The document discusses a regional approach in Italy for integrated municipal solid waste (MSW) management that utilizes a hydrolyser (autoclave) to produce a pelletized engineered fuel called Fluff Pellets from processed MSW. The hydrolyser uses steam and high pressure to further decompose the MSW into a sterile, pathogen-free fuel that is dried and pelletized. Compared to conventional refuse derived fuels, Fluff Pellets allow for more stable, controlled combustion and can be safely stored indefinitely. The process aims to treat MSW on a commercial scale while producing a higher-quality fuel for waste-to-energy applications.

1. HYDROLYSER APPLICATION AND
DEVELOPMENT OF A PELLET
ENGINEERED FUEL FOR MSW
MANAGEMENT IN ITALY
P. ISARD*AND E.A.STERN**
* Dunham Heath Canada Corporation, 3750A Laird Drive, Mississauga, Ontario
L7L 6a8, Canada
** Montclair State University, Department of Earth and Environmental Studies,
1 Normal Avenue, Montclair, New Jersey, USA
Presented at the 5th
International Symposium on Energy from Biomass and Waste (Venice 2014)
17-20 November 2014
San Servolo – Venice, Italy
SUMMARY: A regional innovative approach to integrated treatment train Municipal Solid Waste
(MSW) management on a commercial scale that manufactures a beneficial use product for
incorporation into a Waste to Energy (WTE) process utilizing a Hydrolyser (autoclave) is
discussed. This entails the application of a near continuous-flow Hydrolyser that uses a combination
of steam and high pressure to further decompose the processed MSW waste stream. The process
produces a non-putrescent, pathogen-free, homogeneous fuel product known as Flufftm
. The air
dried Flufftm
is converted into Flufftm
Pellets (Process Engineered Fuel – PEF) which are quite
different from Refuse Derived Fuels (RDF) and Solid Recovered Fuels (SRF); in that, they are non-
putrescent, stable and can be safely stored for many months prior to use. Compared with
conventional RDF and SRF, Flufftm
Pellets allow for a more stable, controlled combustion
environment significantly reducing the risk for incomplete combustion and the undesirable by-
products that can challenge conventional RDF and SRF facilities.
1. INTRODUCTION
The management of Municipal Solid Waste (MSW) from an environmental, sustainable,
economic and socio-political reality perspective continues to be an evolving global challenge.
Associated long-term liability coupled with risk management of MSW transport (and other wastes,
as well) to other regions and/or countries for processing and land filling calls for a more integrated
21st Century approach for a global, transferable environmental management solution. Whereas, the
Not In My Backyard (NIMBY) social and political context continues to be the higher level decision
making driver for moving forward with regional MSW processing utilizing innovative technologies
– landfill disposition, where available, remains the preferred path. In Italy, landfill disposition is the
usual option for MSW management. Though rates from 2001 to 2009 have decreased from 67% to
48%, there is a geographical difference among Italy’s regions in processing their MSW (ETC/STP,
2013). The challenge for developed and developing countries is to consider utilizing “waste” as a

2. resource rather than viewing it as a problem to be dealt with. The latter leads to handling waste in
the most inexpensive and un-sustainable way and does not recognize the long-term implications of
those decisions. The ability to derive a high-quality fuel that can be incorporated into a WTE
process in multiple industrial facilities and power generation complexes should be of social and
political consciousness, as it relates to long-term sustainable outcomes. Regional facilities that can
manage a waste stream as opposed to long-distance transport and land filling are environmentally
protective from both human health and ecological perspectives. Furthermore, economically sound
and socio-political drivers that promote innovative technologies which generate high quality fuel for
beneficial use market streams will create secondary employment opportunities.
The utilization of a continuous flow hydrolyser (as opposed to batch units) produces a PEF
which is hygroscopic, pathogen free (sterile) and has a Btu content of approximately 19,800 Btu’s
per kilogram/20,890 kilojoules as compared to 15,400 Btu’s per kilogram for RDF and SRF.
The disposition and sale of RDF or SRF as fuel pellets has been a challenge since in some
aspects they are still perceived as “waste” and not pathogen free. RDF and SRF are generally
extruded as loose pellets that lose their physical integrity in a relatively short period of time, usually
within a few weeks. Cement plants and power generation plants tend to charge a fee per ton to
accept the RDF from the waste generator; and even though they utilize the RDF as a fuel, they do
not perceive it as a resource and/or feedstock. Furthermore, due to the existing laws in the European
Union (not unlike other countries), these industrial plants are aware of the municipalities need to
material transfer the back-end produced RDF because of the municipality’s reduced option of
placing MSW in landfill sites. This results in a de facto tipping fee charge to the municipality by the
industrial user.
2. MSW HYDROLYSER – PEF PROCESS TRAIN
2.1 Front-end
The primary purpose of the integrated system is to quickly process, in 22 minutes (4.5
tonnes/hr), MSW - either unsorted or sorted and to create a pathogen free, low ash, high yield fuel
to be used as a resource for power generation. The process operates on a continuous basis where
all treatment train steps are automated and controlled by a proprietary Electronic Supervisory
Control System. This system slows or stops as required for the next integrated component – the
Hydrolyser to be batch loaded on a continuous basis with prepared MSW. The System needs to
have proprietary learned knowledge of the controls by using industrial PLCs (programmable logic
controllers) to provide both for discrete control of individual pieces of equipment and total
integration for the entire process line. This not only reduces process down time but also increases
the usable life of the shredder and shredder knives and trouble shoots immediate jamming in the
system during loading.
Typical of sorting and pre-processing, the MSW enters the system. Ferrous and non-ferrous
metals are removed in-line separately. Ferrous metals are removed by magnetic belts and non
ferrous metals are removed by eddy currents, each at several extraction points in the process. The
captured ferrous and nonferrous metals must meet a high standard for resale to scrap metal buyers.
Plastics are generally left in the process at least until market prices makes plastic recycling
economical. Textiles are processed separately in the line prior to drying to assure a consistent fuel
pellet and to allow for lower use of energy in the drying cycle. Inert materials such as glass, rocks
and sand are also removed and the remaining organic portion of the waste is fed into a continuous
flow Hydrolyser (high temperature and high pressure steam autoclave).

3. 2.2 Hydrolyser
Typically autoclaves operate in a batch mode. In comparison, the Hydrolyser in a commercial
operation mode takes in small continuous batch loads and releases them under pressure as the batch
arrives at the Hydrolyser output 22 minutes later. The continuous-flow Hydrolyser uses a
combination of live steam injection and a steam heated jacket to generate and maintain the required
high pressure/high temperature for adequate processing of the organic phase of the MSW stream. It
operates at temperatures, pressures and dwell time longer than surgical instrument autoclaves in
medical settings. This is critical to insure that the post treated product or Flufftm
exiting the
Hydrolyser is sterile, pathogen free and odor free. Once the processed MSW exits the chamber, it is
allowed to rapidly decompress from 650 cmHg (approximately 125 psi) at 175o
C to atmosphere
further aiding the material transformation of the processed waste. The MSW undergoes a physical
change during this stage. The material enters the hydrolyser as shredded MSW of minus 2.54cm.
When it exits the hydrolyser the rapid decompression causes the material to explode and results in
Flufftm
at minus 1.0 cm. The Flufftm
is easily dried for pelletizing through a conventional pellet mill.
Because Flufftm
is loaded with micronutrients and has high water retention capacity, it can be used
beneficially as compost packing in manufactured soil processing as an alternative to use as a fuel
pellet.
2.3 Post Hydrolyzer Processing Steps
2.3.1 Flufftm
Grinder - Sizing)
The Flufftm
is processed through an additional grinder and/or shredder with a nominal 20mm
grate size to ensure the material is adequately sized for the pelletizing process.
2.3.2 Air Dryer
To optimize the pelletizing process, a tumble air dryer is used to reduce the nominal 28% by
weight moisture content of the Flufftm
to approximately less than 10% by weight. Local conditions
may require additional heat to complete the drying process during this phase. The process train uses
natural gas with steam regeneration that can assist with the pellet drying process to reduce energy
utilization within the system.
2.3.3 Pelletizer
Unlike standard RDF, which is extruded, the PEF is produced using a controlled hydraulic
pressure pellet mill. The air dried Flufftm
is converted from its normal fibrous state to a dense 13
mm (nominal diameter) Flufftm
Pellet to optimize the handling, storage and eventual firing of the
pellet in a power generating system or other facilities. The exact pellet size is optimized to reduce
energy and maintenance costs while maximizing combustion efficiency and material handling
characteristics of the fuel that will be compatible with the feeding and combustion systems of the
accepting facility.
2.3.4 Pellet Cooler
From the pelletizer the warm pellets are conveyed to a counter flow pellet cooler. The pellet
cooler is incorporated to improve pellet quality prior to transport and during interim fuel storage.
Once cooled to slightly above ambient temperatures, the Flufftm
Pellets are transferred to the fuel
storage area.

4. 3. Pellet Engineered Fuel (PEF)
3.1 PEF Characteristics
The pressure within the Hydrolyser is 125psi at 350°F (8.62 bars at 175o
C). This a higher
pressure/ temperature combination than is found in hospital autoclaves used to sterilize surgical
instruments. These pressure/temperature characteristics allow the steam to penetrate the cell walls
of the cellulosic material in the MSW as well as the cell walls of any pathogens in the MSW. The
MSW travels continuously through the Hydrolyser from ingress to egress for a period of 22
minutes, while pressure and temperature remain constant. When MSW exits the Hydrolyser, a
material transformation takes place. The sudden pressure drop causes the steam to explode the cell
walls of the cellulosic material and the cell walls of the pathogens. The resultant material is now
Flufftm
. It is pathogen free (sterile) and all moisture is now surface and no longer interstitial, which
allows for faster and more complete drying. The material release takes place in a concrete silo
which absorbs the rapid decompression. (It is a process which resembles how Rice Krispiestm
is
made).
This air dried Flufftm
is then converted into Flufftm
Pellets which are a cleaner and more
consistent fuel product than standard RDF/SRF pellets. Flufftm
pellets have a Btu content of 19,800
Btu’s per kilogram or 20,890 kilojoules. They are non-putrescent, stable and can be safely stored
for many months prior to use. Metals and inert materials are removed by an automated process in
advance of the Hydrolyser. Toxic Characteristic Leaching Procedure (TCLP) analysis of Flufftm
has
consistently shown that the material is safe and complies with applicable US Environmental
Protection Agency regulations. The PEF is manufactured through a highly controlled process to
create a predictable fuel that is 30% higher in energy value over most RDF/SRF.
3.1.1 Difference from RDF
Compared with conventional RDF/SRF, Flufftm
Pellets allow for more stable, controlled
combustion significantly reducing the risk of incomplete combustion and the undesirable by-
products that challenge RDF/SRF combustion. Secondly, the PEF is pathogen and odor free and
therefore can be stored indefinitely. This means the size of the pellet can be changed depending on
use. Thirdly, with the main concern being the chlorine content of RDF, PEF has less than 0.3%
(3000 ppm chlorine unlike the standard RDF/SRF which is usually greater than 0.6% (6000 ppm).
3.1.2 Regulatory Classification as a Waste
Most groups such as cement companies define burning RDF/SRF as burning MSW, not as a
fuel, and thus demand a tipping fee. In the United States, an entity may submit a petition to the US
Environmental Protection Agency (USEPA) for classification as a Non-Hazardous Secondary
Material (NHSM), and therefore, not a waste. When used as a fuel by a third party, the emission
metrics and the handling requirements for NHSMs are significantly more relaxed than those
required for waste. A petition may apply to a class of NHSM and not just a particular facility. The
petition must demonstrate that the material meets legitimate NHSM criteria by addressing the
physical and chemical properties of the material.
Specific test protocol is established by the USEPA and the tests are conducted by independent
third parties. The USEPA will review the data based upon analysis of test data from samples
obtained by following rigorous and well defined sampling criteria submitted. Upon review, USEPA
would provide a “Comfort Letter” defining a waste derived fuel as conforming to NHSM
requirements meeting USEPA’s legitimacy requirements. With respect to PEF, the significance of

5. this “Comfort Letter” is that unlike RDF/SRF which is essentially still a waste material, PEF will
not be considered a waste. This “Comfort Letter” would provide an imprimatur from the USEPA
that PEF burned in combustion units are non-waste fuels in accordance with the requirements in 40
CFR part 241.2(b)(4). To be designated as a non-waste fuel under that section, the rule requires that
processing of NHSM meets the definition of processing in 40 CFR 241.2. Also after processing, the
NHSM must meet the legitimacy criteria for fuels in 40 CFR 241.3 (d)(1). A “Comfort Letter”
could indicate USEPA’s belief that the 40 CFR part 241 regulations would identify fuel generated
by a MSW process and burned in combustion units as a non-waste fuel. Within the EU and Italy, a
re-classification of a PEF as a non-waste would be a significant move forward in developing less
dependence on landfills and a market generator for sustainable fuel product.
4. DISCUSSION
Integrated applications and long-term sustainable solutions for handling of MSW is needed. The
long and protracted regulatory process as well as the socio-economic and political realities perhaps
has not come as far as a societal needs thinks in order to move towards faster implementation until a
crisis situation is at hand. We have seen these situations play out globally in all disciplines of waste
management. In these situations decisions are made hastily, usually are not sustainable since it
takes care of an immediate need (including political) and long-term innovation wanes because the
technological impetus is deflected and the financial capital needed for investments is directed
somewhere else. Hence business as usual continues.
What is discussed in this paper is an innovative application of utilizing a Hydrolyser to produce
a beneficial use Process Engineered Fuel or pelletized Flufftm
with a 30% higher energy value over
most RDF that uses MSW as a feedstock but that can also process organic de-watered sludge which
sets up multiple market driven opportunites within a municipal structure (need for MSW and
sewage treatment sludge). The organic material can have a high moisture content and still be
processed and bring it to a usable fuel pellet as with de-watered sludge. It is conceived that coupled
on the back end of the process, a downdraft gasification system is added that produces synthetic gas
to operate an engine and produce electricity. These applications are different than MRF/SRF/RDF
configurations.
CanmetEnergy, the research arm of Natural Resources Canada, has taken a close look at the PEF
potential for displacing coal as a fuel source. Findings have shown that PEF could replace up to
10% of the thermal content at a coal-fire power plant with no change in operations. Canmet Energy
estimates the greenhouse gas savings to be 2.75 tons CO2 equivalent per ton of coal displaced,
mostly due to the avoided methane emissions from not land filling the material. In this study, PEF
was shown to meet EU standards CEN/TS 15359 (Class 2/2/1) with a Btu similar to coal
(approximately 19,233 btu/kg). It was shown that PEF could be co-fired at a 10% blend without
impact on overall combustion behavior (Geddis and Clements (2013).
Full-scale operational facilities exist in Tennessee, USA and the Caribbean Island of Aruba. The
tropical Caribbean Island had no viable options for disposing the tons of waste generated by the
105,000 residents and thousands of tourists who visit each year. The Island’s landfill, visible to
tourists as they arrive and depart from the major airport on the Island, was overflowing. The
solution was to develop a facility at the edge of the landfill. The Aruban project, which included
design, manufacture, construction, and start-up, took two years to complete. The facility has been
operational since July, 2009. The Aruba facility is 150 tons per day with three process Hydrolyser
lines. With this system there is zero landfill and no need for special environmental systems to be put

6. in place for the venting of expended natural gas. Futhermore, diverting some waste froma landfill
results in Offset Credits to methane avoidance as well as metal recovery. Overall emissions
reduction attributed per tonnes of PEF produced are 2.75 tonnes of CO2 equivalent (Blue Source,
2013).
5. CONCLUSIONS
It is conceived that a multiple-line Hydrolyser process could be sited, designed and constructed
in Italy and the EU. The plan formulation and process outcome would entail:
Creating a regional facility in Italy sited in an Industrial Park that will provide a long- term
integrated MSW solution to the waste collected locally by a municipality (s). A Park of this
type could be developed within a municipality as an Environmental Industrial Park
(EcoPark) that is part of an industrial master plan for a city for recycling and economic
development.
Developing scaleable system lines that are able to adjust to MSW feedstock availability as
opposed to fixed volume infrastructure.
Creating a facility that will divert as close to 100% of residual municipal waste away from
landfills.
Creating energy from waste, reducing the need for fossil fuels (especially reducing dirty
fuels such as coal and petcock).
Creating a cleaner environment, significantly reducing greenhouse gases.
Creating a system that is economical and state of the art for waste processing and production
of energy.
Creating a system that will be profitable for to allow self-financing over an 8 year time.
Creating jobs and tax revenue within the local economy.
Taking leader/ownership in becoming a national leader in technical transfer of innovative
waste management.
REFERENCES
Blue Source (2013). Aspen Integrated Resource Recovery Facility (AIRR) – CCEMC Round 7:
Renewable Energy Fuel Project Proposal: Appendix H: GHG Emission Reduction. Blue Source
Canada ULC. Final report Version 2.1. February 2013. Calgary, Alberta.
ETC/SCP (2013). Muncipal Waste Management in Italy. Prepared by Matteo Ferraris and Susanna
Paleari. European Environment Agency.
Geddis, P. And B. Clements (2013). Co-Firing Process Engineered Fuel With Highvale Coal: Final
Report. Canmet ENERGY. Ottawa, Ontario.