The pulp and paper industry generates a significant amount of pollution and is recognized as one of the most polluting industries in the US. Each pulp and paper facility generates on average over 457,000 pounds of toxic pollutants annually. Great potential exists to improve efficiency and sustainability in this sector through closed loop pulp mills that discharge no wastewater and minimize air and solid waste pollution. Oxygen-based bleaching processes have been shown to be more energy efficient and create less toxicity and hazards for workers compared to chlorine dioxide bleaching. Fully closed loop mills employing oxygen bleaching represent the best path forward for a sustainable kraft pulp industry.
Pulp and Paper Manufacturing and Treatment Of Waste Water
is About:
What is Fiber?
Lignin?Hemicellouse?
Real Explanation of Photosynthesis?
SEM (Scanning Electronic Microscope) Pictures of Trees
Can Plants Survive in Green Light?
How the Pulp is Produced from The Trees (Video) ?
Can We Use Other Than Trees for Pulp Preparation?
Some Information about Locally Located oldest Paper Mills
How the Waste Water Treated from Industries?
Zero Liquid Discharge For Pulp and paper industriesSooraj Garg
This Presentation contains Importance of ZLD, What is ZLD, Challenges in ZLD and a case study of a pulp and paper Industry named "Tamil Nadu Newsprint and Papers Limited, Karur Tamil Nadu"
Pulp and Paper Industry (Pulp Mill, Paper Mill, Printing and Writing Papers, ...Ajjay Kumar Gupta
Pulp and paper are manufactured from raw materials containing cellulose fibers, generally wood, recycled paper, and agricultural residues. In developing countries, about 60% of cellulose fibers originate from non wood raw materials such as bagasse, cereal straw, bamboo, reeds, esparto grass, jute, flax, and sisal. The main steps in pulp and paper manufacturing are: Raw material preparation and handling, Pulp manufacturing, Pulp Washing and Screening, Chemical recovery, Bleaching, Stock Preparation, and Papermaking.
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Niir Project Consultancy Services
106-E, Kamla Nagar, Opp. Spark Mall,
New Delhi-110007, India.
Email: npcs.ei@gmail.com , info@entrepreneurindia.co
Tel: +91-11-23843955, 23845654, 23845886, 8800733955
Mobile: +91-9811043595
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Website : www.entrepreneurindia.co , www.niir.org
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Pulp and Paper Industry, Pulp Mill, Paper Mill, Printing and Writing Papers, Corrugating Medium Paper, Newspapers Hardboards, Pulp and paper processing industry, Pulp and paper making business, Investment Opportunity for Pulp & Paper, Paper Manufacturing Plant, Pulp from Bamboo, Profitable pulp and paper business, Pulp and paper production, Manufacture of corrugating medium paper, Feasibility of recycled newspapers hardboards, Paper mill in India, Best small and cottage scale industries, Book of Pulp and Paper, Paper Board and Paper-based Technology, Book on Pulping and Papermaking, Business guidance for Pulp and paper industry, Business guidance to clients, Business Plan for a Startup Business, Business start-up, Drying of Paper, Great Opportunity for Startup, Hard-Board manufacturing, How to Start a Pulp and paper industry?, How to Start a Pulp and paper Production Business, How to start a successful Pulp and paper business, How to Start Pulp and paper Processing Industry in India, How to Start-Up a paper converting Business, Industry of pulp and paper, Kraft Paper manufacturing, Kraft Paper production, Kraft Process in the paper and pulp industry, Manufacture of pulp and paper, Modern small and cottage scale industries, Most Profitable Pulp and paper Processing Business Ideas, New small scale ideas in Pulp and paper processing industry, Paper and pulp industries, Paper and Pulp Production Technology book, Paper Making Small Business Manufacturing, Paper Production, Paper production line, Paper Production: The Kraft Process in the paper and pulp industry, Paper, Pulp and Paper Conversion, Papermaking Science and Technology book, Production of Kraft Paper, Production of Soda Semi-Chemical Pulp, Profitable small and cottage scale industries, Profitable Small Scale Pulp and paper manufacturing, Project for startups, Pulp and paper Based Profitable Projects, Pulp and paper Based Small Scale Industries Projects, Pulp and Paper Chemistry and Technology
Pulp and Paper Manufacturing and Treatment Of Waste Water
is About:
What is Fiber?
Lignin?Hemicellouse?
Real Explanation of Photosynthesis?
SEM (Scanning Electronic Microscope) Pictures of Trees
Can Plants Survive in Green Light?
How the Pulp is Produced from The Trees (Video) ?
Can We Use Other Than Trees for Pulp Preparation?
Some Information about Locally Located oldest Paper Mills
How the Waste Water Treated from Industries?
Zero Liquid Discharge For Pulp and paper industriesSooraj Garg
This Presentation contains Importance of ZLD, What is ZLD, Challenges in ZLD and a case study of a pulp and paper Industry named "Tamil Nadu Newsprint and Papers Limited, Karur Tamil Nadu"
Pulp and Paper Industry (Pulp Mill, Paper Mill, Printing and Writing Papers, ...Ajjay Kumar Gupta
Pulp and paper are manufactured from raw materials containing cellulose fibers, generally wood, recycled paper, and agricultural residues. In developing countries, about 60% of cellulose fibers originate from non wood raw materials such as bagasse, cereal straw, bamboo, reeds, esparto grass, jute, flax, and sisal. The main steps in pulp and paper manufacturing are: Raw material preparation and handling, Pulp manufacturing, Pulp Washing and Screening, Chemical recovery, Bleaching, Stock Preparation, and Papermaking.
See more
https://goo.gl/MqZ7s4
https://goo.gl/jByd5s
https://goo.gl/4KnBEM
Contact us
Niir Project Consultancy Services
106-E, Kamla Nagar, Opp. Spark Mall,
New Delhi-110007, India.
Email: npcs.ei@gmail.com , info@entrepreneurindia.co
Tel: +91-11-23843955, 23845654, 23845886, 8800733955
Mobile: +91-9811043595
Fax: +91-11-23841561
Website : www.entrepreneurindia.co , www.niir.org
Tags
Pulp and Paper Industry, Pulp Mill, Paper Mill, Printing and Writing Papers, Corrugating Medium Paper, Newspapers Hardboards, Pulp and paper processing industry, Pulp and paper making business, Investment Opportunity for Pulp & Paper, Paper Manufacturing Plant, Pulp from Bamboo, Profitable pulp and paper business, Pulp and paper production, Manufacture of corrugating medium paper, Feasibility of recycled newspapers hardboards, Paper mill in India, Best small and cottage scale industries, Book of Pulp and Paper, Paper Board and Paper-based Technology, Book on Pulping and Papermaking, Business guidance for Pulp and paper industry, Business guidance to clients, Business Plan for a Startup Business, Business start-up, Drying of Paper, Great Opportunity for Startup, Hard-Board manufacturing, How to Start a Pulp and paper industry?, How to Start a Pulp and paper Production Business, How to start a successful Pulp and paper business, How to Start Pulp and paper Processing Industry in India, How to Start-Up a paper converting Business, Industry of pulp and paper, Kraft Paper manufacturing, Kraft Paper production, Kraft Process in the paper and pulp industry, Manufacture of pulp and paper, Modern small and cottage scale industries, Most Profitable Pulp and paper Processing Business Ideas, New small scale ideas in Pulp and paper processing industry, Paper and pulp industries, Paper and Pulp Production Technology book, Paper Making Small Business Manufacturing, Paper Production, Paper production line, Paper Production: The Kraft Process in the paper and pulp industry, Paper, Pulp and Paper Conversion, Papermaking Science and Technology book, Production of Kraft Paper, Production of Soda Semi-Chemical Pulp, Profitable small and cottage scale industries, Profitable Small Scale Pulp and paper manufacturing, Project for startups, Pulp and paper Based Profitable Projects, Pulp and paper Based Small Scale Industries Projects, Pulp and Paper Chemistry and Technology
The bleaching chemistry indicates that pH affects the effectiveness of chlorine dioxide treatment and
the standard recommendations has been to maintain a final stage pH range for brightening with chlorine
dioxide between 3.5 and 4.0. But we used 16% & 17% TAA cooked Clone EH2013 of kappa number 18.7 &
17.4 without Oxygen Delignification (ODL), were bleached in Acidic and Alkaline pH initial chlorine dioxide
(DO) stage, followed by Caustic reinforced Hydrogen peroxide (Ep) and final Chlorine dioxide (D1) stage of
bleaching. At constant bleaching condition both EH2013 pulps show these alkaline pH bleaching methods can
improve the pulp bleachability without affecting pulp strength properties, optical properties, and physical
properties and improved effluent characteristics. The Alkaline pH bleached pulp final brightness 85.7 %ISO
(16% TAA) and 86.5%ISO (17% TAA) are well compared to Acidic pH final brightness 83.4 %ISO (16% TAA)
and 84.4%ISO (17% TAA) initial chlorine dioxide bleaching and followed by extraction reinforced Hydrogen
peroxide and final Chlorine dioxide bleaching. The fiber length, width and curl index of Acidic and Alkaline pH
bleached pulp has not shown any distinct variation, but alkaline pH bleached pulp has shown slightly higher
than Acidic pH bleached Pulp. Both 16&17% TAA cooked pulps filtrate analysis of the Alkaline pH Do stage,
shows lower Colour (14.6 & 15.4%), Total Dissolved Solids (10.7 & 17.9%) and COD (14.2 & 18.0%) than
Acidic pH Do bleaching filtrate. Based on results from the Acidic and Alkaline pH bleaching of EH2013 pulp ,
we found that the optimum pH for initial Do and final D1 chlorine dioxide bleaching stage should be operated
with a final pH close to alkaline, when a typical chlorine dioxide charge is applied and its effluent
characteristics shows lesser inorganic load when compared to acidic effluent .
A Comparative Greenhouse Gas Emission Assessment of Two Gasket Manufacturing ...Zatkoff Seals & Packings
Zatkoff Seals & Packings, the largest independent distributor of seals in North America, commissioned an independent comparative product life cycle emission analysis. This analysis compares the greenhouse gas (GHG) emissions produced by the Synthetic Fiber and Nitrile Butadiene (SFNB) gasket, which is manufactured with the calendering process, to the emissions of the Rubber-Edged Composite (REC) gasket, which is manufactured with the Beater-Addition process.
By comparing the manufacturing process of the REC gasket and the SFNB gasket, it is discovered that the production process matters a great deal for the environment. This study concludes that the SFNB gasket offers significant environmental benefits. The SFNB gasket offers up to 30% emission reductions, including energy savings around water and forestry, when compared to the REC gasket.
International Refereed Journal of Engineering and Science (IRJES)irjes
International Refereed Journal of Engineering and Science (IRJES) is a leading international journal for publication of new ideas, the state of the art research results and fundamental advances in all aspects of Engineering and Science. IRJES is a open access, peer reviewed international journal with a primary objective to provide the academic community and industry for the submission of half of original research and applications
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Identification and Selection of the Best Industrial Wastewater Treatment Tech...theijes
A bench scale model and treatability study was developed for chemical product “detergents, shampoos, toilet soaps and sanitary paper” industry to study the analysis of waste discharge. The main process lines used in the industry are fabric and home care production unit, soap production unit, and sanitary paper production unit. The main environmental problem of the industry is that the industrial wastewater resulting from the facility is not meeting the limits of the environmental regulations for the discharge of wastewater to the sewer network. Accordingly, the industry has to treat the wastewater prior to its discharge to the wastewater sanitary network. The main objectives of this study are management and control of liquid and solid wastes in the industry as well as selecting the different possible treatment trains for the waste water prior to its discharge to the sewer system in order to protect the environment and to gain benefits as much as possible from the wasted materials and identify opportunities for introducing pollution prevention measures and best method for waste minimization as cleaner production system. The study is taking into account all types of waste production including wastewater and solid waste during the production processes activities. Treatment Procedure is conducted through treatability study using two proposed streams of techniques; biological treatment technique (Anaerobic Treatment) and chemical treatment followed by biological treatment technique (Coagulation followed by Sedimentation). According to the different treatment alternatives conducted through the study, it is proved the biological method is not suitable for this type of waste, as the antifoaming chemicals and enzymes present in the wastewater leads to death of the microorganisms and accordingly the failure of the treatment system. As for the chemical treatment, it provided good results in both industrial wastewater mixed with domestic wastewater, and industrial wastewater alone. It also provided good results when using both ferric chloride and aluminum sulphate. It is concluded that the coagulation and Flocculation process followed by plain sedimentation is the most reliable alternative treatment method for this kind of industry using ferric chloride for the wastewater without domestic wastewater. The removal efficiency reached 72 to 79%, 86 to 96%, 83 to 88% and 86% for COD, TSS, Phosphorous, and Oil and Grease respectively.
Biopolymers for Paperboard Extrusion Coating and Converting - SPE FlexPackCon...C. Carey Yang, Ph.D.
Biopolymers have shown promising options for sustainable packaging applications. This article presents an overview of challenges and opportunities in biopolymers for paperboard extrusion coating and converting processes. Material properties, extrusion coating process and equipment requirements, regulatory compliance, and downstream converting are reviewed. The latest developments and emerging trends in biopolymer technology and innovation are discussed.
Sugar cane stalk is a solid biomass waste that can be utilised as a feed for biogas plant. With gratitude to the authors, a paper is made available here for educational putpose.
Single crystallized sugar from Sugar Cane is a large industry of India that generates rural employment and produces useful by-products. an essay about this industry is presented.
Natural rubber tree is cultivated in Asia and a large supplement needed for tyre industry is synthesised based on monomers derived from olefines & benzene.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
Thinking of getting a dog? Be aware that breeds like Pit Bulls, Rottweilers, and German Shepherds can be loyal and dangerous. Proper training and socialization are crucial to preventing aggressive behaviors. Ensure safety by understanding their needs and always supervising interactions. Stay safe, and enjoy your furry friends!
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
TESDA TM1 REVIEWER FOR NATIONAL ASSESSMENT WRITTEN AND ORAL QUESTIONS WITH A...
Pulp paper-pollution
1. Pulp & Paper industry & Pollution – A report from USA-1995
The manufacture of wood pulp is an important method for
chemically converting wood into useful products. It is a
highly important component of the global manufacturing
industry in both economic and environmental terms.
Pulp and paper manufacture can have potentially serious
impacts on environmental quality and hence the health of
both human and wider ecosystems.
In the United States alone, pulp and paper is recognized as
one of the nation's most highly polluting industries. The US--
EPA’s 1994 Toxic Release Inventory (TRI) reported that such
facilities generate the greatest quantities of polluting substances
(measured in pounds per facility) of any industry sector.
Each facility was reported as generating an average of 457,457
pounds of reportable toxic substances every year. In addition, these
industrial plants discharge an estimated 6.01 billion pounds of
other pollutants not covered by the TRI into national waterways
and public sewerage systems.
Great potential exists for both improving efficiency and
moving to sustainability in this industrial sector. Now, the state of
current research and technology development in the field of
1
2. ecologically responsible Kraft pulp manufacture, and
developments designed to mitigate and eliminate human and
environmental health impacts are emphasized. Also explored in
depth is the potential for operating closed loop pulp mills which
discharge no wastewater into our rivers and oceans and minimize
the quantity and toxicity of air pollution and solid waste.
While it is recognized that issues such as sustainable forestry,
control of consumer demand and maximizing the use of recycled
and alternative fibers are critical components in moving the entire
pulp and paper industry onto a sustainable footing, these issues are
not addressed here.
The concept of a closed loop mill aims to eliminate discharges
to the aquatic environment, recycle and reuse all possible solid and
liquid process wastes, and reduce air emissions to the lowest
possible quantity and toxicity. A mill should be able to produce its
primary product, with most of its by-products suitable for use as
secondary products.
To date, much of the by-product in existing mills attempting
to go closed loop is burned as a fuel for the mill. It is far from ideal
reuse for much of the waste-stream. Research must continue to
develop more sustainable reuse options for Kraft pulping solid
wastes, as well as pulping methods that result in purified by-
2
3. products that can serve as feedstock for other manufacturing
processes.
Since the discovery of highly toxic dioxin compounds in pulp
mill effluent there has been a great deal of work on reducing the
toxicity of liquid discharges from pulp mills. There have been
efforts at both end-of-the-pipe control, and at eliminating
precursors to known toxic compounds.
Despite progress on these fronts, a variety of toxic impacts
persist. Genetic to fish and toxicity to micro-organisms that help to
break down waste are still present in secondarily treated effluent
from mills employing only chlorine dioxide as a bleaching agent.
The presence of resin acids and other unidentified constituents
continue to have toxicity problems for all Kraft mills, regardless of
bleaching chemicals.
Ecosystems near pulp mills which meet relatively tough
existing environmental regulations continue to experience
significantly reduced diversity in the plants and animals able to
live near them. These facts emphasize the need to pursue closed
loop strategies.
In this review, the literature on a wide variety of factors that
will influence the overall impact of a pulp mill on its total
environment is discussed. An attempt is made to draw conclusions
about which pathways the research and practical experience
3
4. indicate are the best ways forward to a Kraft pulp industry with the
lowest possible negative influence on its surroundings.
Areas addressed include: effluent toxicity, air emissions,
sludge and solid waste, raw material utilisation (i.e. energy usage,
chemical consumption, wood yield and paper quality), bleaching
methods, capital, conversion and operating costs, and worker and
community health and safety.
Current progress on closed loop mills is reviewed and
evaluated with a particular look at non-bleach plant improvements,
non-process element control to manage the build-up of recycled
chemicals that can harm mill equipment and product quality,
bleaching chemical choices and effects on mill equipment. Finally,
looking to future improvements in the industry, emerging work on
alternative pulping methods is discussed and a summary of next
steps and gaps in existing research is presented.
A different quality and quantity of information is available
for each area reviewed. Effluent toxicity has been, and continues to
be, extensively researched. While the most advanced mills in the
world may have similar final effluent toxicity, those employing
only oxygen based bleaching chemicals continue to have the
lowest toxicity on a full spectrum of toxicity parameters. As
important as this area of study is under existing circumstances,
4
5. closed loop operations will eliminate all toxicity to aquatic
environments by eliminating all discharge into them.
The characteristics of air emissions have not been well
documented, nor have there been adequate comparison studies
between various mill types. The current regulatory standards are
inadequate. Existing data suggest that oxygen based closed loop
operations will have either no difference in air emission impacts,
or an improved one.
However, this conclusion warrants further testing, especially as
emissions to air will continue as a major output of closed loop
mills.
The production of waste fibre sludge should end with a
closed loop pulp mill. Until that time, some sludge will continue
to be produced as mills increase the degree of effluent recycling
they are able to accommodate. An increasing push towards land-
spreading of this material is being seen throughout many
jurisdictions with intensive pulp production. This method of sludge
disposal is an area of concern, as sludge constituents are not well
identified, the sludge in any given mill is highly variable, and the
fate of the sludge on land is not thoroughly researched. Well
designed, independently monitored pilot projects of significant
duration are necessary before this practise becomes widespread.
The closed loop process will likely increase the amount of solid
5
6. waste being generated in the dregs, grit, and ash of pulp mills as
these waste streams become the only remaining options for the
purge of chemicals and elements that can upset the process or
damage equipment. While the quantity of dregs, grit, and ash in a
closed loop mill will increase over current mill designs, total solid
waste will be significantly reduced. Recovery of process chemicals
from these purge points should be maximized. Remaining wastes
will likely be committed to secure landfills. Therefore, more work
on the composition and reprocessing of these waste streams is
needed. The review of total energy consumption is a critical
element of evaluating an ecologically responsible pulp mill.
A major factor in this calculation is the energy balance inherent
in the various bleaching chemicals. Almost without exception, the
literature indicates that oxygen based bleaching sequences have a
superior efficiency over chlorine dioxide based sequences in this
area. Even when combined with potential increased energy
consumption in some oxygen based configurations, these mill
designs are the most energy efficient available.
Wood yield and paper quality are two areas that have been
frequently used by the North American pulp industry, in particular,
to suggest that oxygen based bleaching sequences are neither
ecologically, nor economically preferable. Many of these
comparisons cite reductions in wood yield based on how the wood
6
7. fibre is turned into pulp. This type of comparison is spurious and
has no bearing on yield variations due to the type of bleaching used
in a mill.
Setting aside the yield effects of pulping processes, assertions
made about yield loss due to oxygen based bleaching have been
based on measurements of carbohydrate content in effluent and the
resulting Chemical Oxygen Demand (COD), a standard regulatory
measurement. These have suggested that there is between 0-1%
increase in wood consumption for oxygen based production. These
estimates, based on secondary measurements, have not been
substantiated on a practical basis. The widely reported fall in yield
of 6% at the Wisaforest TCF mill in Finland is thought to be due to
the fact that the mill switches between ECF and TCF pulp
production and as a result is not optimised for TCF production
methods. Södra Cell has not seen a change in wood consumption
since full conversion to TCF bleaching, in common with reports
from the Louisiana Pacific mill in Samoa California after
conversion to TCF. While there is undoubtedly a need to evaluate
the yield aspect in greater detail, on the basis of the available
evidence, yield loss does not appear to be a significant factor
detracting from the overall benefits of using oxygen based bleach
processes.
7
8. Similarly, claims made about inferior pulp quality from oxygen
based sequences, while touching on an area of real concern for a
small portion of the market pulp produced worldwide, seem to
have been exaggerated, presented as representative of the full
spectrum of bleach kraft pulp, and continually based on outdated
information. As a general observation it appears that oxygen based
kraft pulps show no appreciable shortcomings in quality relative to
chlorine dioxide bleached products and that the unhelpful debate
which has surrounded the product quality issue is of rapidly
diminishing relevance both to pulp users and wider consumer
markets.
The costs of converting an existing mill to closed loop
operations are one area where there is extensive and often
contradictory information in the public realm. Finding estimates
that consider all relevant aspects of mill conversion and have
access to enough detailed, mill specific information is nearly
impossible. In general, it appears that costs for converting an
existing mill to a closed loop mill are similar regardless the type of
bleaching chemicals used.
The authors acknowledge that the actual cost of any
conversion will be highly influenced by the state of the mill in
question and we encourage the industry to open the evaluation
8
9. process to public scrutiny. New, or “greenfield”, mills appear to be
most financially efficient when designed to optimise oxygen based
bleaching and a closed-loop design. As mentioned earlier, the
health and welfare of the workers and surrounding communities
has not been a regular feature of the debate over how to achieve an
ecologically responsible pulp industry. This is most unfortunate
because workers, especially, have often had to suffer increased
workplace concentrations of hazardous chemicals as laws
preventing those substances from entering the environment have
been tightened. While no bleaching chemical is benign, the
conclusion based on extensive available literature is that the
oxygen based bleaching chemicals present the least immediate and
long term hazards for workers and the general public. Additionally,
the upgrades inherent in designing a closed loop mill should
include other improvements, such as light gas strippers and, non-
condensable gas collection systems which will remove hazardous
and foul smelling pollution from the air and increase workplace
safety.
Finally, we look at the current state of efforts to build and run an
actual industrial scale closed loop mill. Efforts continue with both
chlorine dioxide- and oxygen-based systems.
Progress has been made on both fronts, with non-process element
control (i.e., managing the build-up of chemicals which are
9
10. recycled through the system), being the greatest barrier to final
effluent circuit closure. For oxygen based sequences, the control of
metals in the process liquor is the greatest challenge, while systems
employing chlorine dioxide must have as primary concern
equipment damage from the recirculation of highly corrosive
chlorides.
A final solution has not been achieved for either approach.
However, mills attempting to run chlorine dioxide based recycling
have not been able to run at a high degree of effluent closure for
extended periods. Oxygen based sequences have reached the
lowest effluent levels and been able to run for longer periods
between system purges.
The conclusion, given the best research in all of these areas,
is that oxygen based, closed loop kraft pulp mills are the best route
forward to a successful and ecologically responsible kraft pulp
industry.
10