This document provides information on biomass cofiring in coal-fired boilers at federal facilities. It discusses how biomass cofiring can (1) reduce operating costs by substituting a portion of coal with lower-cost biomass fuels, (2) increase the use of renewable energy sources, and (3) enhance energy security. Key points include that biomass cofiring is most economically attractive when facilities have existing coal boilers and access to steady, low-cost biomass supplies, and that several federal sites have demonstrated biomass cofiring can lower costs with minimal modifications to boilers and fuel handling systems.
The convergence of high energy prices,
global warming potential, general environmental
pollution, home-grown energy imperatives,
and green energy possibilities has
created opportunities that far-sighted companies
can capture and the public expects.
The convergence of high energy prices,
global warming potential, general environmental
pollution, home-grown energy imperatives,
and green energy possibilities has
created opportunities that far-sighted companies
can capture and the public expects.
Promoting Renewable Energy Technologies through Public Private Partnership_NR...Nawa Raj Dhakal
Paper presented in international workshop on "Financing Village Level Energy for Development in Asia Pacific" jointly organized by ADB, GVEP & FDC in Manila
Construction IT Research - Climate Change AgendaŽiga Turk
Addressing climate change is one of the key technological challenges of the present and
the near future. With about a half of the energy being used in the built environment and
with a huge proportion being used by the transportation sector, the construction
industry will be a very important player. The paper presents the general context of the
climate change discussion. It identifies construction industry as a double winner in this
process, potentially benefiting both from the changes in nature as well as from
governments' measures. There are many things construction industry can accomplish
without much additional research, even more, however, if it moves beyond the current
state of the art, particularly in building automation and the use of ICT throughout the
building's life cycle. The paper concludes by identifying the emerging research and
development agenda in the field constriction informatics.
published in: in B.H.V. Topping, L.F. Costa Neves, R.C. Barros, (Editors), "Trends in Civil and Structural
Engineering Computing", Saxe-Coburg Publications, Computational Science, Engineering & Technology
Series, ISSN 1759-3158; Stirlingshire, UK, Chapter 19, pp 413-423, 2009. doi:10.4203/csets.22.19
Renewable and low carbon energy capacity study for the East of Englandcrifcambs
Richard Summers from The Landscape Partnership and Andrew Turton from AECOM shared their findings from work commissioned by the Department for Energy and Climate Change (DECC) to identify the potential for renewable energy in the East of England. This study highlighted the renewable energy resources for Cambridgeshire.
Presented to Councillors on 28 September 2011.
Register for the international thermochemical biomass conference...
"tcbiomass2009"
September 16-18, 2009
Chicago, Illinois, USA
http://www.gastechnology.org/tcbiomass2009
Measures to reduce the energy consumption have been suggested in a separate document. After the adoption of the ones that
the management thinks appropriate, the moment will be for the centre to think of a more economic and environmental friendly manner to generate its own energy.
Closing the Carbon Cycle for Sustainability - Peter Eisenberger (October 15, ...Graciela Chichilnisky
Closing the Carbon Cycle for Sustainability - A Key Strategy for Environmental Protection, Energy Security, and Economic Development - Peter Eisenberger (October 15, 2012 @ Oxford University)
Biomass co firing in coal power plantsJossie Xiong
Why choose wood pellets in co-firing plant with coal? Lowest cost renewable power and Relatively easy to implement features makes wood pellets more popular than other biomass for co-firing.
Promoting Renewable Energy Technologies through Public Private Partnership_NR...Nawa Raj Dhakal
Paper presented in international workshop on "Financing Village Level Energy for Development in Asia Pacific" jointly organized by ADB, GVEP & FDC in Manila
Construction IT Research - Climate Change AgendaŽiga Turk
Addressing climate change is one of the key technological challenges of the present and
the near future. With about a half of the energy being used in the built environment and
with a huge proportion being used by the transportation sector, the construction
industry will be a very important player. The paper presents the general context of the
climate change discussion. It identifies construction industry as a double winner in this
process, potentially benefiting both from the changes in nature as well as from
governments' measures. There are many things construction industry can accomplish
without much additional research, even more, however, if it moves beyond the current
state of the art, particularly in building automation and the use of ICT throughout the
building's life cycle. The paper concludes by identifying the emerging research and
development agenda in the field constriction informatics.
published in: in B.H.V. Topping, L.F. Costa Neves, R.C. Barros, (Editors), "Trends in Civil and Structural
Engineering Computing", Saxe-Coburg Publications, Computational Science, Engineering & Technology
Series, ISSN 1759-3158; Stirlingshire, UK, Chapter 19, pp 413-423, 2009. doi:10.4203/csets.22.19
Renewable and low carbon energy capacity study for the East of Englandcrifcambs
Richard Summers from The Landscape Partnership and Andrew Turton from AECOM shared their findings from work commissioned by the Department for Energy and Climate Change (DECC) to identify the potential for renewable energy in the East of England. This study highlighted the renewable energy resources for Cambridgeshire.
Presented to Councillors on 28 September 2011.
Register for the international thermochemical biomass conference...
"tcbiomass2009"
September 16-18, 2009
Chicago, Illinois, USA
http://www.gastechnology.org/tcbiomass2009
Measures to reduce the energy consumption have been suggested in a separate document. After the adoption of the ones that
the management thinks appropriate, the moment will be for the centre to think of a more economic and environmental friendly manner to generate its own energy.
Closing the Carbon Cycle for Sustainability - Peter Eisenberger (October 15, ...Graciela Chichilnisky
Closing the Carbon Cycle for Sustainability - A Key Strategy for Environmental Protection, Energy Security, and Economic Development - Peter Eisenberger (October 15, 2012 @ Oxford University)
Biomass co firing in coal power plantsJossie Xiong
Why choose wood pellets in co-firing plant with coal? Lowest cost renewable power and Relatively easy to implement features makes wood pellets more popular than other biomass for co-firing.
Fischer-Tropsch fuels based on biomass and coal with carbon capture and storage could play a significant role in forming a low carbon transportation system. Coal and solar energy can power such a system allowing more of the carbon to be be integrated into the biofuels.
Poyry - Is biocoal a game changer? - Point of ViewPöyry
Climate change concerns have created pressure to reduce fossil fuel consumption. Once heralded as the next big thing - the potential of co-firing biomass in coal boilers
has been limited by the significant capital investment required to modify fuel handling and combustion systems. However, biocoal can be co-fired in existing coal fired power plants, produced from a vast array of feedstock, and is efficient to ship, even over long distances. Is biocoal a game changer?
Biomass Co-firing: A transition to a low carbon futurevivatechijri
Biomass Co-firing is defined as simultaneous combustion of different fuels in the same boiler, provides one alternative to achieve emission reductions. This is not only accomplished by replacing fossil fuel with biomass, but also as a result of interaction of fuel reactants of different origin, e.g. biomass and coal. Co-firing of biomass with fossil fuels provides means to reduceSO2, and CO2 emissions and it also may reduce NOx emissions. It is assumed that there is no net emission of CO2 from biomass combustion as plants use the same amount of CO2 during growth that is released in combustion On the other hand utilisation of solid biofuels and wastes sets new demand for boiler process control and boiler design, as well as for combustion technologies, fuel blend control and fuel handling system. Cofiring with biomass offers a cheap and practical means of reducing carbon emissions using existing infrastructure. The capital costs for cofiring are generally low and usually limited to retrofitting boilers with modified delivery systems. Compared to other forms of renewable energy, the up-front investments needed for co-firing in existing boilers are fairly small. These retrofits are often substantially less expensive than the costly overhaul that would otherwise be needed to meet increased emissions standards.
Biomass refers to a group of organic materials that can be used to generate electric and thermal power. Sources of biomass are: herbaceous and woody plants, agriculture and forestry wastes and residues, landfill gases, animal wastes, municipal wastes, and other organic material.
Five steps to a sustainable biobased product economy - Adrian Higson.pdfNNFCC
A chemicals and materials industry based on fossil inputs extracted from the geosphere is inherently unsustainable and can never achieve zero greenhouse gas emissions.
A transition to alternative raw materials is required. However this transition cannot be based on simply switching one type of raw material for another. The approach to transition must be wider and based on a re-engineering of the way the economy and society approaches manufacturing and the consumption of products.
The linear model of consumption (take, make, dispose) needs to end, as must approaches to consumerism such as fast fashion. To speak metaphorically, we must put the brakes on the material economy and change direction.
To be successful the biobased economy must overcome two critical challenges: cost and acceptance. The latter being the key to overcoming the former. The widespread acceptance by politicians, industrialists, and consumers, of the need to move away from fossil-based materials and that practical means of doing so exist, would unblock a flow of resources and market interventions allowing the scale up of technology, market development and learning-by-doing, which will inexorably reduce production costs.
The legitimacy of a biobased economy has been widely questioned by both NGOs and the academic community , , , , , although criticisms have been largely targeted at biofuel production, these concerns do apply to biobased products. Questions over biodiversity impacts, social concerns around food security and even questions on the potential for greenhouse gas emission reductions, serve to reduce the acceptance of biobased products as a positive change for good.
This position has resulted in the discrepancy seen between positive policy statements, recognising the need to reduce fossil inputs in material production , and the inertia in the actual practical implementation of policy , . This issue is widely recognised in the UK and across the EU, although the biobased economy is attractive in many ways; for too many stakeholders, it’s complicated and fraught with risk, resulting in a wait and see, or a let’s focus on simpler issues mind set.
Therefore, unlocking the full potential of the biobased economy rests on achieving a consensus between stakeholders on what a transition could look like and how it should be managed.
At the heart of societies environmental crisis lies the issue of overconsumption , . This isn’t just a fossil fuel problem but an issue which cuts across the extraction of all natural resources whether it be water for food production, sand for concrete manufacture or precious metals for mobile phones. ‘Earth overshoot day’ creeps earlier each year and it is argued that without intervention, by 2030 we will need 2 planets to meet both our resource needs and absorb societies wastes.
Five steps to a sustainable biobased product economy - Adrian Higson.pdfNNFCC
This presentation was given at the CHEMUK 2022 - The UK Chemical & Process Industries Expo. The presentation discusses the need for societal, systems and technological change to enable a move from the current petrochemical industry to an industry based on the use of sustainable carbon resources. A presentation is accompanied by a discussion paper which can be accessed at https://www.nnfcc.co.uk/news-transition-biobased-economy-steps.
Search and Society: Reimagining Information Access for Radical FuturesBhaskar Mitra
The field of Information retrieval (IR) is currently undergoing a transformative shift, at least partly due to the emerging applications of generative AI to information access. In this talk, we will deliberate on the sociotechnical implications of generative AI for information access. We will argue that there is both a critical necessity and an exciting opportunity for the IR community to re-center our research agendas on societal needs while dismantling the artificial separation between the work on fairness, accountability, transparency, and ethics in IR and the rest of IR research. Instead of adopting a reactionary strategy of trying to mitigate potential social harms from emerging technologies, the community should aim to proactively set the research agenda for the kinds of systems we should build inspired by diverse explicitly stated sociotechnical imaginaries. The sociotechnical imaginaries that underpin the design and development of information access technologies needs to be explicitly articulated, and we need to develop theories of change in context of these diverse perspectives. Our guiding future imaginaries must be informed by other academic fields, such as democratic theory and critical theory, and should be co-developed with social science scholars, legal scholars, civil rights and social justice activists, and artists, among others.
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Connector Corner: Automate dynamic content and events by pushing a buttonDianaGray10
Here is something new! In our next Connector Corner webinar, we will demonstrate how you can use a single workflow to:
Create a campaign using Mailchimp with merge tags/fields
Send an interactive Slack channel message (using buttons)
Have the message received by managers and peers along with a test email for review
But there’s more:
In a second workflow supporting the same use case, you’ll see:
Your campaign sent to target colleagues for approval
If the “Approve” button is clicked, a Jira/Zendesk ticket is created for the marketing design team
But—if the “Reject” button is pushed, colleagues will be alerted via Slack message
Join us to learn more about this new, human-in-the-loop capability, brought to you by Integration Service connectors.
And...
Speakers:
Akshay Agnihotri, Product Manager
Charlie Greenberg, Host
"Impact of front-end architecture on development cost", Viktor TurskyiFwdays
I have heard many times that architecture is not important for the front-end. Also, many times I have seen how developers implement features on the front-end just following the standard rules for a framework and think that this is enough to successfully launch the project, and then the project fails. How to prevent this and what approach to choose? I have launched dozens of complex projects and during the talk we will analyze which approaches have worked for me and which have not.
"Impact of front-end architecture on development cost", Viktor Turskyi
Femp biomass co-firing (2007)
1. DOE/EE-0288
Leading by example,
saving energy and Biomass Cofiring in Coal-Fired Boilers
taxpayer dollars
in federal facilities
Using this time-tested fuel-switching technique in existing federal boilers
helps to reduce operating costs, increase the use of renewable energy,
and enhance our energy security
Executive Summary
To help the nation use more domestic fuels and renewable energy technologies—and increase
our energy security—the Federal Energy Management Program (FEMP) in the U.S. Department
of Energy, Office of Energy Efficiency and Renewable Energy, assists government agencies in
developing biomass energy projects. As part of that assistance, FEMP has
prepared this Federal Technology Alert on biomass cofiring technologies. This
publication was prepared to help federal energy and facility managers make
informed decisions about using biomass cofiring in existing coal-fired boilers
at their facilities.
The term “biomass” refers to materials derived from plant matter such as
trees, grasses, and agricultural crops. These materials, grown using energy
from sunlight, can be renewable energy sources for fueling many of today’s
energy needs. The most common types of biomass that are available at
potentially attractive prices for energy use at federal facilities are waste
wood and wastepaper.
The boiler plant at the
Department of Energy’s One of the most attractive and easily implemented biomass energy technologies is cofiring
Savannah River Site co-
fires coal and biomass.
with coal in existing coal-fired boilers. In biomass cofiring, biomass can substitute for up
to 20% of the coal used in the boiler. The biomass and coal are combusted simultaneously.
When it is used as a supplemental fuel in an existing coal boiler, biomass can provide the
following benefits: lower fuel costs, avoidance of landfills and their associated costs, and
reductions in sulfur oxide, nitrogen oxide, and greenhouse-gas emissions. Other benefits,
such as decreases in flue gas opacity, have also been documented.
Biomass cofiring is one of many energy- and cost-saving technologies to emerge as feasible for
federal facilities in the past 20 years. Cofiring is a proven technology; it is also proving to be
life-cycle cost-effective in terms of installation cost and net present value at several federal sites.
Energy-Saving Mechanism
Biomass cofiring projects do not reduce a boiler’s total energy input requirement. In fact, in
a properly implemented cofiring application, the efficiency of the boiler will be the same as
it was in the coal-only operation. However, cofiring projects do replace a portion of the non-
renewable fuel—coal—with a renewable fuel—biomass.
Cost-Saving Mechanisms
Overall production cost savings can be achieved by replacing coal with inexpensive biomass
fuel sources—e.g., clean wood waste and waste paper. Typically, biomass fuel supplies should
cost at least 20% less, on a thermal basis, than coal supplies before a cofiring project can be
economically attractive.
U.S. Department of Energy
Energy Efficiency Internet: www.eere.energy.gov/femp/
and Renewable Energy No portion of this publication may be altered in any form without
Bringing you a prosperous future where energy prior written consent from the U.S. Department of Energy, Energy
is clean, abundant, reliable, and affordable Efficiency and Renewable Energy, and the authoring national laboratory.
2. Federal Technology Alert
Payback periods are typically To make economical use of captive investment of $850,000 was
between one and eight years, wood waste materials—primarily required, resulting in a simple
and annual cost savings could bark and wood chips that are payback period for the project
range from $60,000 to $110,000 unsuitable for making paper—the of less than four years. The net
for an average-size federal boiler. U.S. pulp and paper industry has present value of the project,
These savings depend on the cofired wood with coal for evaluated over a 10-year analysis
availability of low-cost biomass decades. Cofiring is a standard period, is about $1.1 million.
feedstocks. However, at larger- mode of operation in that indus-
Test burns at SRS have shown that
than-average facilities, and at try, where biomass fuels provide
the present stoker boiler fuel han-
facilities that can avoid disposal more than 50% of the total fuel
dling equipment required no
costs by using self-generated input. Spurred by a need to reduce
modification to fire the biomass/
biomass fuel sources, annual fuel and operating costs, and
coal mixture successfully. No fuel-
cost savings could be signifi- potential future needs to reduce
feeding problems were experi-
cantly higher. greenhouse gas emissions, an
enced, and no increases in main-
increasing number of industrial-
tenance are expected to be needed
Application and utility-scale boilers outside
at the steam plant. Steam plant
Biomass cofiring can be applied the pulp and paper industry are
personnel have been supportive
only at facilities with existing being evaluated for use in cofiring
of the project. Emissions measure-
coal-fired boilers. The best oppor- applications.
ments made during initial testing
tunities for economically attrac- showed level or reduced emissions
tive cofiring are at coal-fired facili- Case Study Summary for all eight measured pollutants,
ties where all or most of the fol- The U.S. Department of Energy’s and sulfur emissions are expected
lowing conditions apply: (1) coal (DOE) Savannah River Site (SRS) to be reduced by 20%. Opacity
prices are high; (2) annual coal in Aiken, South Carolina, has levels also decreased significantly.
usage is significant; (3) local or installed equipment to produce The project will result in a reduc-
facility-generated supplies of bio- “alternate fuel,” or AF, cubes from tion of about 2,240 tons per year
mass are abundant; (4) local land- shredded office paper and finely in coal usage at the facility.
fill tipping fees are high, which chipped wood waste. After a series
means it is costly to dispose of of successful test burns have been Implementation Barriers
biomass; and (5) plant staff and completed to demonstrate accept-
management are highly motivated For utility-scale power generation
able combustion, emissions, and
to implement the project success- projects, acquiring steady, year-
performance of the boiler and fuel
fully. As a rule, boilers producing round supplies of large quantities
processing and handling systems,
less than 35,000 pounds per hour of low-cost biomass can be diffi-
cofiring was expected to begin in
(lb/hr) of steam are too small to cult. But where supplies are avail-
2003 on a regular basis. The bio-
be used in an economically attrac- able, there are several advantages
mass cubes offset about 20% of
tive cofiring project. to using biomass for cofiring opera-
the coal used in the facility’s two
tions at federal facilities. For exam-
traveling-grate stoker boilers. The
ple, federal coal-fired boilers are
Field Experiences project should result in annual coal
typically much smaller than
Cofiring biomass and coal is a time- cost savings of about $112,000.
utility-scale boilers, and they
tested fuel-switching strategy that Cost savings associated with avoid- are most often used for space
is particularly well suited to a ing incineration or landfill disposal heating and process heat appli-
stoker boiler, the type most often of office waste paper and scrap cations. Thus, they do not have
found at coal-fired federal facili- wood from on-site construction utility-scale fuel requirements.
ties. However, cofiring has been activities will total about $172,000
successfully demonstrated and In addition, federal boilers needed
per year. Net annual savings from
practiced in all types of coal for space heating typically operate
the project, after subtracting the
boilers, including pulverized- primarily during winter months.
$30,000 per year needed to oper-
coal boilers, cyclones, stokers, During summer months, waste
ate the AF cubing facility, will be
and fluidized beds. wood is often sent to the mulch
about $254,000. An initial capital
3. Federal Technology Alert
market, which makes the wood • Economics is the driving factor. energy efficiency and renewable
unavailable for use as fuel. Thus, Project economics largely deter- energy projects. Projects can be
federal coal-fired boilers could mine whether a cofiring proj- funded through Energy Savings
become an attractive winter mar- ect will be implemented. Performance Contracts (ESPCs),
ket for local wood processors. This Selecting sites where waste Utility Energy Services Contracts,
has been one of the driving fac- wood supplies have already or appropriations. Among these
tors behind a cofiring demonstra- been identified will reduce resources is a Technology-Specific
tion at the Iron City Brewery overall costs. Larger facilities “Super ESPC” for Biomass and
in Pittsburgh, Pennsylvania. with high capacity factors— Alternative Methane Fuels (BAMF),
those that operate at high loads which facilitates the use of bio-
These are some of the major policy year-round—can utilize more mass and alternative methane
and economic issues and barriers biomass and will realize fuels to reduce federal energy con-
associated with implementing greater annual cost savings, sumption, energy costs, or both.
biomass cofiring projects at assuming that wood supplies
federal sites: are obtained at a discount in Through the BAMF Super ESPC,
comparison to coal. This will FEMP enables federal facilities
• Permit modifications may be
also reduce payback periods. to obtain the energy- and cost-
required. Permit requirements
savings benefits of biomass and
vary from site to site, but
Conclusion alternative methane fuels at no
modifications to existing
up-front cost to the facility. More
emissions permits, even for DOE FEMP, with the support of
information about FEMP and
limited-term demonstration staff at the DOE National Labor-
atories and Regional Offices, offers BAMF Super ESPC contacts and
projects, may be required for
many services and resources to contract awardees is provided in
cofiring projects.
help federal agencies implement this Federal Technology Alert.
Disclaimer
This report was sponsored by the United States Department of Energy, Energy Efficiency and Renewable Energy, Federal Energy
Management Program. Neither the United States Government nor any agency or contractor thereof, nor any of their employees,
makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or useful-
ness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned
rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or other-
wise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or
any agency or contractor thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of
the United States Government or any agency or contractor thereof.
5. Federal Technology Alert
Contents
Abstract .....................................................................................................2
About the Technology ..............................................................................3
Application Domain
Cost-Saving Mechanisms
Other Benefits
Installation Requirements
Federal-Sector Potential ............................................................................9
Estimated Savings and Market Potential
Laboratory Perspective
Application .............................................................................................11
Application Prerequisites
Cost-Effectiveness Factors
Where to Apply
What to Avoid
Equipment Integration
Maintenance
Equipment Warranties
Codes and Standards
Costs
Utility Incentives
Project Financing and Technical Assistance
Technology Performance........................................................................17
Field Experience
Fuel Supply and Cost Savings Calculations ...........................................17
Case Study — Savannah River Cofiring Project ....................................18
Facility Description
Existing Technology Description
New Technology Description
Energy Savings
Life-Cycle Cost
Performance Test Results
The Technology in Perspective ..............................................................20
Manufacturers.........................................................................................21
Biomass Pelletizing Equipment
Boiler Equipment/Cofiring Systems
Biomass and Alternative Methane Fuels (BAMF) Super ESPC
Competitively Awarded Contractors
For Further Information .........................................................................21
Bibliography ...........................................................................................21
Appendix A: Assumptions and Explanations for Screening Analysis .......23
Appendix B: Blank Worksheets for Preliminary Evaluation of a
Cofiring Project ......................................................................................24
Appendix C: Completed Worksheets for Cofiring Operation at
Savannah River Site ................................................................................28
Appendix D: Federal Life-Cycle Costing Procedures and BLCC
Software Information .............................................................................31
Appendix E: Savannah River Site Biomass Cofiring Case Study:
NIST BLCC Comparative Economic Analysis ........................................33
FEDERAL ENERGY MANAGEMENT PROGRAM — 1
6. Federal Technology Alert
Abstract nity for federal energy managers This Federal Technology Alert was
to use a greenhouse-gas-neutral produced as part of the New Tech-
Biomass energy technologies con-
renewable fuel while reducing nology Demonstration activities
vert renewable biomass fuels to
energy and waste disposal costs in the Department of Energy’s
heat or electricity. Next to hydro-
and enhancing national energy Federal Energy Management Pro-
power, more electricity is gener-
security. Specific requirements gram, which is part of the DOE
ated from biomass than from any
will depend on the site. But in Office of Energy Efficiency and
other renewable energy resource
general, cofiring biomass in an Renewable Energy, to provide
in the United States. Biomass
existing coal-fired boiler involves facility and energy managers
cofiring is attracting interest
modifying or adding to the fuel with the information they need
because it is the most economical
handling, storage, and feed sys- to decide whether to pursue bio-
near-term option for introducing
tems. Fuel sources and the type mass cofiring at their facilities.
new biomass resources into today’s
of boiler at the site will dictate
energy mix. This publication describes biomass
fuel processing requirements.
cofiring, cost-saving mechanisms,
Biomass cofiring can be economi- and factors that influence its per-
cal at federal facilities where most formance. Worksheets allow the
or all of these criteria are met: reader to perform preliminary cal-
current use of a coal-fired boiler, culations to determine whether
access to a steady supply of com- a facility is suitable for biomass
petitively priced biomass, high cofiring, and how much it would
coal prices, and favorable regu- save annually. The worksheets
latory and market conditions for also allow required biomass sup-
renewable energy use and waste plies to be estimated, so managers
reduction. Boilers at several fed- can work with biomass fuel bro-
eral facilities were originally kers and evaluate their equipment
designed for cofiring biomass needs. Also included is a case
with coal. Others were modified study describing the design, oper-
after installation to allow cofiring. ation, and performance of a bio-
Some demonstrations—e.g., at the mass cofiring project at the DOE
Figure 1. The NIOSH boiler plant was
modified to cofire biomass with coal. National Institute of Occupational Savannah River Site in Aiken,
Safety and Health (NIOSH) Bruce- South Carolina. A list of contacts
ton Boiler plant in Pittsburgh, and a bibliography are also
Cofiring is the simultaneous com-
Pennsylvania (Figure 1)—show included.
bustion of different fuels in the
that, under certain circumstances,
same boiler. Cofiring inexpensive
only a few boiler plant modifica-
biomass with fossil fuels in exist-
tions are needed for cofiring.
ing boilers provides an opportu-
2 — FEDERAL ENERGY MANAGEMENT PROGRAM
7. Federal Technology Alert
About the Technology involves substituting biomass for cles, because biomass is a more
a portion of the fossil fuel used volatile fuel. Biomass that does
Biomass is organic material from
in a boiler. not meet these specifications is
living things, including plant
likely to cause flow problems in
matter such as trees, grasses, Cofiring inexpensive biomass with
the fuel-handling equipment or
and agricultural crops. These fossil fuels in existing federal boilers
incomplete burnout in the boiler.
materials, grown using energy provides an opportunity for federal
General biomass sizing require-
from sunlight, can be good energy managers to reduce their
ments for each boiler type men-
sources of renewable energy energy and waste disposal costs
tioned here are shown in Table 1.
and fuels for federal facilities. while making use of a renewable
fuel that is considered greenhouse-
Wood is the most commonly used Table 1. Biomass sizing requirements.
gas-neutral. Cofiring biomass
biomass fuel for heat and power.
counts toward a federal agency’s Existing Type Size Required
The most economical sources of of Boiler (inches)
goals for increasing the use of
wood fuels are wood residues from
renewable energy or “green power” Pulverized coal ≤1/4
manufacturers and mill residues,
(environmentally benign electric
such as sawdust and shavings; Stoker ≤3
power), and it results in a net cost
discarded wood products, such Cyclone ≤1/2
savings to the agency. Cofiring
as crates and pallets; woody yard Fluidized bed ≤3
biomass also increases our use of
trimmings; right-of-way trim-
domestic fuels, thus enhancing
mings diverted from landfills; More detailed information follows
the nation’s energy security.
and clean, nonhazardous wood about the cofiring options for
debris resulting from construction This publication focuses on the stoker and pulverized-coal federal
and demolition work. Using these most promising, near-term, boilers.
materials as sources of energy proven option for cofiring—using
recovers their energy value and solid biomass to replace a portion Stoker boilers. Most coal-fired boilers
avoids the need to dispose of of the coal combusted in existing at federal facilities are stokers,
them in landfills, as well as coal-fired boilers. This type of similar to the one shown in the
other disposal methods. cofiring has been successfully schematic in Figure 2. Because
demonstrated in nearly all coal- these boilers are designed to fire
Biomass energy technologies con- fairly large fuel particles on travel-
fired boiler types and configura-
vert renewable biomass fuels to ing or vibrating grates, they are
tions, including stokers, fluidized
heat or electricity using equip- the most suitable federal boiler
beds, pulverized coal boilers, and
ment similar to that used for type for cofiring at significant
cyclones. The most likely opportu-
fossil fuels such as natural gas, biomass input levels. In these
nities at federal facilities will be
oil, or coal. This includes fuel- boilers, fuel is either fed onto
found at those that have stokers
handling equipment, boilers, the grate from below, as in under-
and pulverized coal boilers. This
steam turbines, and engine gener- feed stokers, or it is spread evenly
is because the optimum operating
ator sets. Biomass can be used in across the grate from fuel spread-
range of cyclone boilers is much
solid form, or it can be converted ers above the grate, as in spreader
larger than that required at a fed-
into liquid or gaseous fuels. Next stokers. In the more common
eral facility, and few fluidized bed
to hydropower, more electricity spreader-fired traveling grate stoker
boilers have been installed at fed-
is generated from biomass than boiler, solid fuel is mechanically
eral facilities for standard, non-
from any other renewable energy or pneumatically spread from the
research uses.
resource in the United States. front of the boiler onto the rear
One of the most important keys of the traveling grate. Smaller par-
Cofiring is a fuel-diversification ticles burn in suspension above
to a successful cofiring operation
strategy that has been practiced the grate, while the larger particles
is to appropriately and consistently
for decades in the wood products burn on the grate as it moves the
size the biomass according to the
industries and more recently in fuel from the back to the front of
requirements of the type of boiler
utility-scale boilers. Several fed- the boiler. The ash is discharged
used. Biomass particles can usually
eral facilities have also cofired from the grate into a hopper at
be slightly larger than coal parti-
biomass and coal. Cofiring the front of the boiler.
FEDERAL ENERGY MANAGEMENT PROGRAM — 3
8. Federal Technology Alert
03381101
The retrofit requirements for cofir-
ing in a stoker boiler will vary,
depending on site-specific issues.
If properly sized biomass fuel can
be delivered to the facility pre-
mixed with coal supplies, on-site Gas burners
capital expenses could be negligi-
ble. Some facilities have multiple Hopper
coal hoppers that discharge onto Receiving
a common conveyor to feed fuel bin
Traveling
into the boiler. Using one of the grate
Overfire
existing coal hoppers and the Boiler air
associated conveying equipment injection
for biomass could minimize new
Figure 2. Schematic of a typical traveling-grate spreader-stoker.
capital expenses for a cofiring
project. Both methods have been
Front end loader
successfully employed at federal to blend wood Metal
stoker boilers for implementing and coal supplies detector Magnetic
(coal and wood
a biomass cofiring project. If blend is passed separator Dump conveyor
through existing #1 Walking floor trailer
neither of these low-cost options Dump or dump truck
coal pulverizers)
is feasible, new handling and Wood conveyor #2
pile Scale
storage equipment will need
03381102
to be added. The cost of these
additions is discussed later. Figure 3. Schematic of a blended-feed cofiring arrangement for a pulverized
coal boiler.
Pulverized coal boilers. There are two
primary methods for cofiring bio- heat input basis. If the biomass is the NIOSH Bruceton boiler plant
mass in a pulverized coal boiler. obtained at a significant discount in Pennsylvania and DOE’s Savan-
The first method, illustrated in to current coal supplies, the addi- nah River Site in South Carolina—
Figure 3, involves blending the tional expense may be warranted have been considering implement-
biomass with the coal before the to offset coal purchases to a ing commercial cofiring applica-
fuel mix enters the existing pul- greater degree. tions. Other federal sites with
verizers. This is the least expensive cofiring experience include KI
method, but it is limited in the Application Domain Sawyer Air Force Base in Michi-
amount of biomass that can be gan, Fort Stewart in Georgia, Puget
The best opportunities for cofiring
fired. With this blended feed Sound Naval Shipyard in Washing-
biomass with fossil fuels at federal
method, only about 3% or less ton, Wright- Patterson Air Force
facilities are at sites with regularly
of the boiler’s heat input can be Base in Ohio, Brunswick Naval
operating coal-fired boilers. Biomass
obtained from biomass at full Air Station in Maine, and the
cofiring has been successfully
boiler loads because of limitations Red River Army Depot in Texas.
demonstrated in nearly all coal-
in the capacity of the pulverizer.
fired boiler types and configura- More than 100 U.S. companies or
The second method, illustrated in tions, including stokers, fluidized organizations have experience in
Figure 4 on page 5, requires beds, pulverized coal boilers, and cofiring biomass with fossil fuels,
installing a separate processing, cyclones. The least expensive and many cofiring boilers are in
handling, and storage system opportunities are most likely to operation today. Most are found
for biomass, and injecting the be for stoker boilers, but cofiring in industrial applications, in
biomass into the boiler through in pulverized coal boilers may which the owner generates a
dedicated biomass ports. Although also be economically attractive. significant amount of biomass
this method is more expensive, it At least 10 facilities in the federal residue material (such as sawdust,
allows greater amounts of biomass sector have had experience with scrap wood, bark, waste paper, or
to be used—up to 15% more on a cardboard or agricultural residues
biomass cofiring. Two facilities—
4 — FEDERAL ENERGY MANAGEMENT PROGRAM
9. Federal Technology Alert
Metal
detector
Magnetic
separator
Conveyor #1 Wood
Disc screener pile
Grinder Scale Front end Walking floor trailer 03381103
loader or dump truck
Rotary
airlock
feeder
Separator
Air Intake Exhaust
Bin Dedicated biomass
vent injection Existing coal
Injection ports
Wood silo Boiler
Scale Pressure
blower
Figure 4. Schematic of a separate-feed cofiring arrangement for a pulverized coal boiler.
like orchard trimmings and coffee project, and the next 10 states were Within each group in Table 2,
grounds) during manufacturing. classified as having good potential. states are shown in alphabetical
Using these residues as fuel allows See Table 2 and Figures 5 and 6. order, because slight variations
organizations to avoid landfill in rankings result from selecting
and other disposal costs and off- Table 2. States with most attractive weighting-factor values. The anal-
sets some purchases of fossil fuel. conditions for biomass cofiring. ysis was intended simply to indi-
Most ongoing cofiring operations cate which states have the most
Cofiring helpful conditions for econom-
are in stoker boilers in one of four
Potential State
industries: wood products, agricul- ically successful cofiring projects.
ture, textiles, and chemicals. High Connecticut It found that the Northeast, South-
Potential Delaware east, Great Lakes states, and
A screening analysis was done to Florida Washington State are the most
determine which states have the Maryland attractive locations for cofiring
most favorable conditions for a Massachusetts projects.
financially successful cofiring proj- New Hampshire
New Jersey Utility-scale cofiring projects are
ect. The primary factors consid-
New York shown on the map in Figure 5.
ered were average delivered state Pennsylvania
coal prices, estimated low-cost These sites are in or near states
Washington
biomass residue supply density identified by the screening model
Good Alabama as having good or high potential
(heat content in Btu of estimated Potential Georgia
available low-cost biomass resi- for cofiring. This increases confi-
Indiana
dues per year per square mile of dence that the states selected by
Michigan
state land area), and average state Minnesota the screening process were reason-
landfill tipping fees. See Appendix North Carolina able choices. Figure 6 shows the
A for a more detailed discussion. Ohio locations of existing federal coal-
South Carolina fired boilers. There is good corre-
The top 10 states in the analysis Tennessee spondence between the locations
were classified as having high Virginia of these facilities and the states
potential for a biomass cofiring identified as promising for cofiring.
FEDERAL ENERGY MANAGEMENT PROGRAM — 5
10. Federal Technology Alert
pay off the initial investment—
by switching part of the fuel sup-
ply to biomass. Federal facilities
that operate coal-fired boilers but
are not in states on the list in
Table 2 could still be good candi-
dates for cofiring if specific condi-
tions at their sites are favorable.
“Wild card” factors, such as the
impact of a motivated project
manager or biomass resource
supplier, the local availability
of biomass, and the fact that a
large federal facility or campus
could act as its own source of
biomass fuel, capitalizing on
03381104
fuel cost reductions while avoid-
High potential for a Good potential for a
biomass cofiring project biomass cofiring project ing landfill fees. These factors
Locations of existing utility Locations of existing operational could easily tip the scales in
power plants cofiring biomass coal plants within the Federal System favor of a particular site. The
Figure 5. States with most favorable conditions for biomass cofiring, based on coal-fired boilers in Alaska
high coal prices, availability of biomass residues, and high landfill tipping fees. could be examples of good
candidates not located in
highly rated states because of
WA a long heating season, large
(57) NH
MT VT (49) ME size, and very high coal prices.
ND (50) (46)
OR (19) (26) MN
(34) (56) MA The map in Figure 6 indicates
ID SD WI NY (48)
(26) WY MI (71) average landfill tipping fees for
(29) (33) (32) RI
(23) IA each state. It also shows cities
NV NE PA(51) NJ (41)
(15) (24) (31) CT in which fairly recent local bio-
UT IN OH (74)(61)
CO IL (26) (29) WA
(29) mass resource supply and cost
CA (16) KS MO (25) (39) VA MD DE
(29) (25) (27) KY(27) (38) (43) (47) studies have been performed,
AZ NC(30) as reported in Urban Wood Waste
NM OK TN(28)
(20) AR
(16) (21) Resource Assessment (Wiltsee 1998).
(18)
MS AL GA SC
Additional information on poten-
TX (19) (25) (25) (29)
AK (23) LA tial biomass resource supplies near
(22) federal facilities can be obtained
(42) FL
(41) from the DOE program manager
HI
(50) for the Technology-Specific Super
03381105 ESPC for Biomass and Alternative
High potential for a Good potential for a Methane Fuels, or BAMF; contact
biomass cofiring project biomass cofiring project
information can be found later in
(##) State average tipping Locations of recent local
fee ($/ton)* biomass supply studies this publication. To encourage
*Source: Chartwell Information Publishers, Inc., 1997. new projects under the BAMF
Super ESPC, the National Energy
Figure 6. Average tipping fee and locations of local biomass supply studies
Technology Laboratory (NETL)
(Chartwell 1997, Wiltsee 1998).
has compiled a database that
Coal-fired federal boilers in the biomass if annual coal use is high identifies federal facilities within
20 states indicated in the study enough to obtain significant 50 miles of 10 or more potential
would be promising for cofiring annual cost savings—enough to sources of wood waste.
6 — FEDERAL ENERGY MANAGEMENT PROGRAM
11. Federal Technology Alert
Cost-Saving Mechanisms mated the quantities and costs of dry biomass would have a heating
Cofiring operations are not imple- unused and discarded wood resi- value of about 7,000 Btu/lb, com-
mented to save energy—they are dues in the United States, large pared with an average of 11,500
implemented to reduce energy quantities of biomass are available Btu/lb for the coal used at DoD
costs as well as the cost of other at delivered costs well below the facilities. Each ton of biomass
facility operations. In a typical $2.10 per million Btu average will thus offset 7,000/11,500 =
cofiring operation, the boiler price of coal at the DoD facilities. 0.61 ton of coal. If the biomass
requires about the same heat Coal prices at other federal facili- is used to replace coal at $49/ton,
input as it does when operating ties are likely to be similar. each ton of biomass is worth
in a fossil-fuel-only mode. When $49/ton x 0.61 = $30 in fuel cost
For example, if 15% of the coal
cofiring, the boiler operates to savings. The typical cost of pro-
used at a boiler were replaced by
meet the same steam loads for cessing biomass waste material
biomass delivered to the plant for
heating or power-generation into a form suitable for use in a
$1.25 per million Btu, annual fuel
operations as it would in fossil- boiler is $10 per ton, so the net
cost savings for the average DoD
fuel-only mode; usually, no costs savings per ton of biomass
boiler described above would be
changes in boiler efficiency residues could be about $56:
more than $120,000. Neither the
result from cofiring unless a $66/ton for the fuel and landfill
cofiring rate of 15% of the boiler's
very wet biomass is used. With cost savings minus $10/ton for
total heat input, nor the delivered
no change in boiler loads, and the biomass processing cost. This
price of $1.25 per million Btu, is
no change in efficiency, boiler assumes that the biomass is avail-
unrealistic, especially for stoker
energy usage will be the same. able at no additional transporta-
boilers. Higher cofiring rates and
The primary savings from cofiring tion costs, as is the case at the
lower biomass prices are common
are cost reductions resulting from Savannah River Site.
in current cofiring projects. Note
(1) replacing a fraction of high- that the cost of most biomass If the average DoD facility using a
cost fossil fuel purchases with residues will range from $2 to coal-fired boiler could obtain bio-
lower cost biomass fuel, and (2) $3 per million Btu, so successful mass fuel by diverting its own
avoiding landfill tipping fees or cofiring project operators must residues from landfill disposal,
other costs that would otherwise try to obtain the biomass fuel the net annual cost savings would
be required to dispose of the at a low price. be about $560,000 per year. This
biomass. would require about 10,000 tons
The average landfill tipping fee in
According to data obtained from of biomass residues per year, a
the United States is about $36 per
the Defense Energy Support quantity higher than most federal
ton of material dumped. Average
Center (DESC), the average facilities generate internally. The
tipping fees for each state are
delivered cost of coal for 18 coal- savings generated by a real cofir-
shown in Figure 6. If significant
fired boilers operated by the ing project would be expected to
quantities of clean biomass
Department of Defense (DoD) fall somewhere between the
residues—such as paper, card-
was about $49 per ton in 1999, two examples given here—
board, or wood—are generated
or about $2.10 per million Btu. between $120,000 and $560,000
at a federal site, and if some of
(The average coal heating value per year. They would probably
that material can be diverted from
for those boilers is about 11,500 depend on using some biomass
landfill disposal and used as fuel
Btu/lb) Coal costs for those facili- materials generated on site and
in a boiler, the savings generated
ties ranged from $1.60 to $3 per some supplied by a third party.
would be equivalent to about
million Btu, depending on the $66 per ton of biomass: $36/ton
location, coal type, and annual Other Benefits
by avoiding the tipping fee, and
quantity consumed. The average $30/ton by replacing the coal When used as a supplemental fuel
annual coal cost for these boilers with biomass. Since biomass has in an existing coal boiler, biomass
was about $2 million and ranged a lower heating value than coal, can provide the following bene-
from $28,000 to $8.9 million per it takes more than one ton of bio- fits, with modest capital outlays
year. According to three independ- mass to offset the heat provided for plant modifications:
ently conducted studies that esti- by one ton of coal. A ton of fairly
FEDERAL ENERGY MANAGEMENT PROGRAM — 7
12. Federal Technology Alert
• Reduced fuel costs. Savings in • Renewable energy when needed. modifications to existing opera-
overall production costs can Unlike other renewable energy tional procedures, such as increas-
be achieved if inexpensive technologies like those based ing over-fire air, may also be nec-
biomass fuel sources are avail- on solar and wind resources, essary. Increased fuel feeder rates
able (e.g., clean wood waste). biomass-based systems are are also needed to compensate for
Biomass fuel supplies at prices available whenever they are the lower density and heating
20% or more below current needed. This helps to accelerate value of biomass. This does not
coal prices will usually pro- the capital investment payoff usually present a problem at fed-
vide the cost savings needed. rate by producing more heat eral facilities, where boilers typi-
• Reduced sulfur oxide and nitrogen or power per unit of installed cally operate below their rated
oxide emissions. Because of dif- capacity. output. When full rated output
ferences in the chemical is needed, the boiler can be oper-
• Market-ready renewable energy
composition of biomass and ated in a coal-only mode to avoid
option. Cofiring offers a fast-
coal, emissions of acid rain derating.
track, low-cost opportunity
precursor gases—sulfur oxides to add renewable energy Expected fuel sources and boiler
(SOx) and nitrogen oxides capacity economically at type dictate fuel processing
(NOx)—can be reduced by
federal facilities. requirements. For suspension
replacing coal with biomass.
firing in pulverized coal boilers,
Because most biomass has • Fuel diversification. The ability
biomass should be reduced to a
nearly zero sulfur content, to operate using an additional
particle size of 0.25 in. or smaller,
SOx emissions reductions fuel source provides a hedge
with moisture levels less than
occur on a one-to-one basis against price increases and
25% when firing in the range
with the amount of coal supply shortages for existing
of 5% to 15% biomass on a heat
(heat input) offset by the fuels such as stoker coals. In
input basis. Equipment such as
biomass. Reducing the coal a cofiring operation, biomass
supply to the boiler by 10% hoggers, hammer mills, spike rolls,
can be viewed as an opportu-
will reduce SOx emissions and disc screens may be required
nity fuel, used only when the
by 10%. Mechanisms that to properly size the feedstock.
price is favorable. Note that
lead to NOx savings are Local wood processors are likely
administrative costs could
more complicated, and to own equipment that can ade-
increase because of the need
relative savings are typically quately perform this sizing in
to purchase multiple fuel
less dramatic than the SOx return for a processing fee. Other
supplies; this should be
reductions are, on a percent- boiler types (cyclones, stokers,
considered when evaluating
age basis. and fluidized beds) are better suited
this benefit.
to handle larger fuel particles.
• Landfill cost reductions. Using • Locally based fuel supply. The
waste wood as a fuel diverts Two common forms of processed
most cost-effective biomass
the material from landfills biomass are shown in Figure 7,
fuels are usually supplied
and avoids landfill disposal along with a typical stoker coal,
from surrounding areas, so
costs. shown in the center of the photo.
economic and environmental
Recent research and demonstra-
• Reduced greenhouse-gas emissions. benefits will accrue to local
tion on several industrial stoker
Sustainably grown biomass is communities.
boilers in the Pittsburgh area has
considered a greenhouse-gas-
shown that wood chips (on the
neutral fuel, since it results in Installation Requirements
right) are preferable to mulch-like
no net carbon dioxide (CO2)
Specific requirements depend on material (on the left) for cofiring
in the atmosphere. Using bio-
the site that uses biomass in cofir- with coal in stoker boilers that
mass to replace 10% of the coal
ing. In general, however, cofiring have not been designed or
in an existing boiler will reduce
biomass in an existing coal boiler previously reconfigured for
the net greenhouse-gas emis-
requires modifications or addi- multifuel firing. The chips are
sions by approximately 10% if
tions to fuel-handling, processing, similar to stoker coal in terms
the biomass resource is grown
storage, and feed systems. Slight of size and flow characteristics;
sustainably.
8— FEDERAL ENERGY MANAGEMENT PROGRAM
13. Federal Technology Alert
therefore, they cause minimal The potential savings resulting occur. In terms of CO2 reductions,
problems with existing coal- from using the technology at this would be equivalent to remov-
handling systems. Using a mulch- typical federal facilities with ing about 1,000 average-sized
like material, or a biomass supply existing coal-fired boilers were automobiles from U.S. highways.
with a high fraction of fine parti- estimated as part of the technol-
Additional indirect benefits could
cles (sawdust size or smaller) can ogy-screening process of FEMP’s
also occur. If the biomass fuel
cause periodic blockage of fuel New Technology Demonstration
would otherwise be sent to a land-
flow openings in various areas activities. Payback periods are fill to decay over a period of time,
of the conveying, storage, and usually between one and eight methane (CH4) would be released
feed systems. These blockages years, and annual fuel cost sav- to the atmosphere as a by-product
can cause significant maintenance ings range from $60,000 to of the decomposition process,
increases and operational prob- $110,000 for a typical federal assuming no landfill-gas-capturing
lems, so fuel should be processed boiler. Savings depend on the system is installed. Since CH4 is
to avoid those difficulties. With availability of low-cost biomass 21 times more powerful than CO2
properly sized and processed feedstocks. The savings would in terms of its ability to trap heat
biomass fuel, cofiring operations be greater if the federal site can in the atmosphere and increase
have been implemented success- avoid landfill costs by using its the greenhouse effect, cofiring
fully without extensive modifica- own clean biomass waste mate- at one typical coal-fired federal
tions to equipment or operating rials as part of the biomass fuel facility could avoid decomposition
procedures at the boiler plant. supply. processes that would be equiva-
lent to reducing an additional
Estimated Savings and Market
Federal-Sector Potential
29,000 tons of CO2 emissions
Potential per year.
The National Renewable Energy
A large percentage of federal facili- Laboratory (NREL) conducted a Payback periods using cofiring
ties with coal-fired boilers have study for FEMP of the economic at suitable federal facilities are
the potential to benefit from this and environmental impacts of between one and eight years.
technology. However, as noted, biomass cofiring in existing fed- Annual cost savings range from
the potential is highest in areas eral boilers, as well as associated about $60,000 to $110,000 for
with high coal prices, easy-to- savings. Results of the study are a typical federal boiler, if low-
obtain biomass resources, and presented in Tables 3 through 6 cost biomass feedstocks are avail-
high landfill tipping fees. on pages 10 and 11. As shown in able. There are more than 1500
Table 6, cofiring bio- industrial-scale stoker boilers in
mass with coal at operation in the United States.
one typical coal- If federal technology transfer
fired federal facility efforts result in cofiring projects
will replace almost at 50 boilers (this is about 7%
3,000 tons of coal of existing U.S. stokers), the
per year, could resulting CO2 reductions would
divert up to about be about 405,000 tons/yr (the
5,000 tons of bio- equivalent of removing about
mass from landfills, 50,000 average-size cars from U.S.
and will reduce net highways), and SO2 reductions
carbon dioxide would be about 6,700 tons/yr.
(CO2) emissions by If all biomass materials used in
more than 8,000 these boilers were diverted from
tons per year and landfills with no gas capture, the
Figure 7. Comparison of two biomass residues with coal. sulfur dioxide (SO2) greenhouse-gas equivalent of an
Because they are similar in size and flow characteristics, emissions by about additional 1.45 million tons of
wood chips (right) flow more like coal (center) in stoker 136 tons per year.
CO2 emissions would be avoided.
boilers. Wood chips can thus be used in existing boilers
Reductions in NOx
with minimal modifications to fuel-handling systems.
emissions could also (Continued on page 11)
Mulch-like processed wood (left) is more problematic.
FEDERAL ENERGY MANAGEMENT PROGRAM — 9
14. Federal Technology Alert
Table 3. Example economics of biomass cofiring in power generation applications (vs. 100 percent coal).
Net
Example Heat Total Annual Production Production
Plant from Biomass Unit Cost for Cost Payback Cost, no Cost, with
Size Biomass Power Cost Cofiring Savings Period Cofiring Cofiring
Boiler Type (MW) (%) (MW) ($/kW)1 Retrofit ($) ($/yr)2 (years) (¢/kWh)3 (¢/kWh)3
Stoker
(low cost) 15 20 3.0 50 150,000 199,760 0.8 5.25 5.03
Stoker
(high cost) 15 20 3.0 350 1,050,000 199,760 5.3 5.25 5.03
Fluidized bed 15 15 2.3 50 112,500 149,468 0.8 5.41 5.24
Pulverized coal 100 3 3.0 100 300,000 140,184 2.1 3.26 3.24
Pulverized coal 100 15 15.0 230 3,450,000 700,922 4.9 3.26 3.15
Notes:
1Unit costs are on a per kW of biomass power basis (not per kW of total power).
2Net annual cost savings = fuel cost savings – increased O&M costs.
3Based on data obtained from EPRI's Technical Assessment Guide, 1993, EIA's Costs of Producing Electricity, 1992, UDI's Electric
Power Database, EPRI/DOE's Renewable Energy Technology Characterizations, 1997, coal cost of $2.10/MBtu, biomass cost of
$1.25/MBtu, and capacity factor of 70%.
Table 4. Example environmental impacts of cofiring in power generation applications (vs. 100 percent coal).
Example Annual Annual Annual
Plant Heat Reduced Biomass CO2 SO2 NOx
Size from Coal Use Used Savings Savings Period
Boiler Type (MW) Biomass (tons/yr) (tons/yr)1 (tons/yr)2 (tons/yr) (tons/yr)
Stoker
(low cost) 15 20% 10,125 16,453 27,843 466 N/A
Stoker
(high cost) 15 20% 10,125 16,453 27,843 466 N/A
Fluidized bed 15 15% 7,578 12,314 20,839 349 N/A
Pulverized coal 100 3% 7,429 12,072 20,430 342 N/A
Pulverized coal 100 15% 37,146 60,362 102,151 1,709 N/A
Notes:
1Depending on the source of biomass, “biomass used” could be avoided landfilled material.
2Carbon savings can easily be calculated from CO savings (i.e., carbon savings = 12/44 x CO savings).
2 2
Table 5. Example economic of biomass cofiring in heating applications (vs. 100 percent coal).
Example No. of Heat from Biomass Total Cost Net Annual Payback
Boiler Size Boilers Biomass Capacity Unit Cost for Cofiring Cost Savings Period
(steam lb/hr) at Site (steam lb/hr) (steam lb/hr) ($/lb/hr)1 Retrofit ($) ($/yr)2 (years)
120,000 2 15% 36,000 2.8 100,075 41,628 2.4
Notes:
1Unit costs are on a per unit of biomass capacity basis (not per unit of total capacity).
2Assumptions: coal cost of $2.10/MBtu and capacity factor of 25% (based on data from coal-fired federal boilers), biomass cost of
$1.25/MBtu.
10— FEDERAL ENERGY MANAGEMENT PROGRAM
15. Federal Technology Alert
Table 6. Potential environmental impact of cofiring in heating applications (vs. 100 percent coal).
Annual Annual Annual
No. of Reduced Biomass CO2 SO2 NOx
Cofiring Coal Use Used Savings Savings Period
Projects1,2 (tons/yr) (tons/yr)3 (tons/yr)4 (tons/yr) (tons/yr)
1 2,947 5,057 8,103 136 N/A
2 5,893 10,114 16,206 271 N/A
10 29,466 50,570 81,030 1,355 N/A
50 147,328 252,851 405,151 6,777 N/A
Notes:
1There are approximately 1500 industrial stoker boilers operating today.
2Assumptions for the average project were: 120,000 lb/hr steam capacity per boiler, 2 boilers at site, 15% heat from biomass, and a
25% capacity factor.
3Depending on the source of biomass, “biomass used” could be avoided landfilled material.
4Carbon savings can easily be calculated from CO savings (i.e., carbon savings = 12 / 44 x CO savings).
2 2
Laboratory Perspective that, in general, NOx emissions be used more easily as fuel at
Since the 1970s, DOE and NETL decrease with cofiring as a result existing coal-fired facilities. In
have worked with alternative fuels of the lower nitrogen content of a separate project with funding
such as solid waste and refuse- most woody biomass in relation from NETL, the University of
derived fuel. In 1995, NETL, to coal, and the greater volatility Missouri-Columbia’s Capsule
Sandia National Laboratories, and of biomass in relation to coal. Pipeline Research Center exam-
NREL sponsored a workshop that The greater volatility of biomass ined the potential for compacting
led to several projects evaluating results in a natural staging of the various forms of biomass into
technical and commercial issues combustion process that can small briquettes or cubes for use
associated with biomass cofiring. reduce NOx emissions to levels as supplemental fuels at existing
These projects included research below those expected on the coal-fired boilers. The results indi-
conducted or sponsored by NETL, basis of fuel nitrogen contents. cated that biomass fuel cubes
NREL, Sandia, and Oak Ridge could be manufactured and deliv-
DOE, NETL, and the Electric Power
National Laboratory (ORNL) on ered to a power plant for as little
Research Institute (EPRI) also col-
char burnout; ash deposition; as $0.30 per million Btu, or less
laborated on short-term demon-
NOx behavior; cofiring demon- than $5 per ton. This price
stration projects. Several of the
stration projects using various included all capital and operating
demonstrations took place at
boiler types, coal/biomass feed- costs for the manufacturing facility
federal facilities in the Pittsburgh
stock combinations, and fuel plus transportation costs within
area. They found no significant
handling systems; reburning for a 50-mile radius. The analysis
impact on boiler efficiency at low
enhanced NOx reduction; and the assumed the facility would
levels of cofiring. Fuel procure-
use of ash. These efforts have led collect a $15-per-ton tipping
ment, handling, and preparation
to improved and documented fee for biomass delivered to the
were found to require special
knowledge about the impacts site. See the bibliography for
attention.
of cofiring biomass with coal more detailed information on
in a wide range of circumstances. In addition, DOE’s Idaho National biomass cofiring research activities
Energy and Environmental Labor- and published results of research
Results from a joint Sandia/NETL/ atory (INEEL) and DOE’s Savan- led by DOE and its laboratories.
NREL project found that in terms nah River Site have biomass-
of slagging and fouling, wood was cubing equipment that can Application
more benign than herbaceous convert paper and wood waste This section addresses technical
crops. It has also been shown materials into a form that can aspects of biomass cofiring in
FEDERAL ENERGY MANAGEMENT PROGRAM — 11
16. Federal Technology Alert
coal-fired boilers, including the access to local expertise in dirt. It may also be possible
range of situations in which cofir- collecting and processing to arrange storage through
ing technology can be used best. waste wood. This expertise the biomass fuel provider.
First, prerequisites for a successful can be found primarily
• Receptive plant operators at the
biomass cofiring application are among companies specializ-
federal facility. At the very
discussed, as well as the factors ing in materials recycling,
least, increases will be
that influence the cost-effective- mulch, and wood products.
necessary in administrative
ness of projects. Design and inte-
• Boiler plant equipped with a bag- activities associated with
gration considerations are also
house. Cofiring biomass with adding a new fuel to a boiler
discussed and include equipment
coal has been shown to plant’s fuel mix. In addition,
and installation costs, installation
increase particulate emissions new or additional boiler con-
details, maintenance, and permit-
in some applications in com- trol and maintenance proce-
ting issues.
parison to coal-only opera- dures will be required to use
tion. If the existing facility is biomass effectively. As
Application Prerequisites
already equipped with a bag- opposed to a capital improve-
The best opportunities for cofiring house or cyclone separation ment project, which requires
occur at sites in which many of devices, this should not be a one-time installation and
the following criteria apply: significant problem; in other minimal attention afterwards
• Existing, operational coal-fired words, it should not cause (such as equipment upgrades),
boiler. It is possible to cofire noncompliance with particu- a cofiring operation requires
biomass with fossil fuels late emissions standards. The ongoing changes in fuel pro-
other than coal; however, existing baghouse or cyclone curement, fuel-handling, and
the similarities in the fuel- typically provides sufficient boiler control operations.
handling systems required particulate filtration to allow Receptive boiler plant opera-
for both coal and biomass stack gases to remain in com- tors and management are
(because they are both solid pliance with air permits. How- therefore instrumental in
fuels) usually make cofiring ever, some small coal-fired implementing and sustaining
less expensive at coal-fired boilers are not equipped with a successful cofiring project.
facilities. An exception could these devices. Instead, they
• Favorable regulatory climate for
be cofiring applications in use methods such as natural
renewable energy. As of Febru-
which the biomass fuel is gas overfiring to reduce par-
ary 2003, 28 states had either
gas piped to the boiler from ticulate emissions. In such
enacted electricity restructur-
a nearby landfill. Cofiring cases, a new baghouse may
ing legislation or issued orders
with landfill gas has been be required to permit cofiring
to open their electricity mar-
done in both coal-fired and biomass at significant input
kets to competition. Most of
natural-gas-fueled boilers, levels, and this would increase
these states have established
but is less common than project costs significantly.
some type of incentive pro-
solid-fuel cofiring because of • Storage space available on site. gram to encourage more
the need for a large boiler Unless the biomass is imme- installations of renewable
very close to the landfill. diately fed into a boiler’s energy technologies. Since
• Local expertise for collecting and fuel-handling system upon biomass is a renewable energy
processing biomass. Most boiler delivery, a temporary staging resource, some states may
operators at federal facilities area at the boiler plant will provide favorable conditions
are not likely to be interested be needed to store processed for implementing a cofiring
in purchasing and operating biomass supplies. An ideal project through incentive
equipment to process biomass storage facility would have programs, technical assis-
into a form that can be used at least a concrete pad and tance, or flexible permitting
as boiler fuel.Thus, it is advan- a roof to minimize the accu- procedures.
tageous for the facility to have mulation of moisture and
12 — FEDERAL ENERGY MANAGEMENT PROGRAM