Biorefinery Symposium Maps out a Green Future
June 1, 2007 By Pulp & Paper Canada
At the PAPTAC 93rd Annual Meeting in February 2007, there were four packed sessions in a Biorefinery Symposium organized by the Canadian Forest Biorefinery Network (CFBR) and chaired by Honghi Tran (U…
At the PAPTAC 93rd Annual Meeting in February 2007, there were four packed sessions in a Biorefinery Symposium organized by the Canadian Forest Biorefinery Network (CFBR) and chaired by Honghi Tran (University of Toronto), with Tom Browne (Paprican) and Jean Paris (cole Polytechnique) as co-chair of the Symposium Organizing Committee.
Forest biomass was the focus of most presenters. During Montreal’s coldest week of the winter, Tom had to remind delegates that public concern about global warming now means that all things renewable and carbon-neutral are suddenly sexy. Given this context, he set the stage for the Symposium by highlighting why the pulp and paper industry is so well positioned with its: in-depth knowledge of forest biomass; large-scale industrial infrastructure located near the forests; and lots of experience processing biomass, making steam and power, treating the effluents and shipping products to market. The compelling concept is that synergies can be achieved when a biorefinery is integrated into an existing pulp mill.
A succinct summary of the government perspective on the forest biorefinery was given by Jim Farrell (Canadian Forest Service). It is an opportunity to increase the value of outputs from the forest resource, to develop new bio-products and markets, to reduce greenhouse gases and to enhance employment in forest-dependent communities. Given that the Canadian forest sector has had to face so many international and domestic challenges recently, the biorefinery can be part of a new model for the industry, based on innovation and diversification.
Tom Gale (Tembec) gave an insightful talk as the senior manager of an existing biorefinery at Temiscaming. He asked if a forest biorefinery would be a band-aid or a panacea for the industry. Driven by the need to reduce effluent from their specialty sulphite mill, over a 25-year period Tembec has incrementally added the production of lignosulphonates, resins, ethanol and anaerobic biogas. The key to success has been to maximize the use of facilities by creating new products with the highest possible net value. Gale concluded that rather than a panacea, biorefineries will be an essential component of the future of forest products in Canada: like table stakes in a game of poker, biorefineries will be what it takes to stay in the game.
Lyle Biglow gave more details of Tembec’s super-green biorefinery success in a later talk: the company is Canada’s second largest industrial alcohol supplier, fermenting the residual sugars in spent cooking liquor. This route to ethanol consumes so little fossil fuel that it is claimed to be the only “truly green” ethanol in North America, putting those fossil-consuming corn-based ethanol producers to shame. Tembec is the world’s second largest supplier of lignosulphonates, used as a cement additive, for animal feed and for carbon black in tire manufacture. Their anaerobic sludge treatment makes methane to displace natural gas on-site in Temiscaming.
European Union (EU) supported research on the pulp mill biorefinery is well underway and Peter Axelgard (STFI) covered some of the current projects aimed at simultaneous production of fibres, composites, chemicals, fuels and energy. He outlined progress in five pilot thermochemical projects, each EU-supported with 5 to 10 million euro. They include high temperature black liquor gasification at Pitea, Sweden, and a pressure fluidized bed gasifier at Esbo, Finland. Syngas, transportation fuels, hydrogen and oil refinery feedstock were typical end products along with heat and steam. The EU program is guided by a biorefinery task force with a strategic plan, and a fresh set of proposals is now being evaluated. Peter also described a kraft mill pilot plant for lignin precipitation, and its successor, a 4000 t/y demonstration plant in start-up at Backhammer, Sweden. Capital expenditures are typically EU funded up to 50%, and operating expense support depends on R&D content. In answer to questions, he said that EU carbon-credits were not a significant driver of biorefinery technology development because of their uncertainty. And you could hear the jaws drop when he gave a frank opinion of ethanol production directly from wood: too complicated; while pentose fermentation remains unproven, it will be twice as costly as ethanol from wheat straw. At present, according to Axelgard, it seems better to use wood hemicellulose directly as a chemical product and he gave an example of a controlled-dissolution seed coating application.
Greg Penner (NeoBio Consulting) came with a biorefinery message from the Canadian Chemical Industry. Chemicals manufactures are faced with an increasingly costly fossil feedstock. At the same time, they are increasingly profitable and eager for new opportunities. The Canadian industry has a current focus on some specific high volume products. A case in point is the remarkable $5.5 billion/y ethylene industry, built over the past 30 years on natural gas from Western Canada. The sector is interested in monomers for product streams that already exist (ethylene, propylene, butylenes, benzene, etc.) and polymers for product streams that do not yet exist. Penner viewed pulp mills as perfectly positioned to process large volumes of forest biomass in a biorefinery and generally left the impression that there are some wonderful opportunities waiting to be developed.
Jean Paris concluded the first session by describing the activities of the Paprican-Papier task force on Biorefining, which had: proposed the RD&D work needed based on Industry Canada Innovation Roadmap and the four Canadian Forest Innovation Council White Papers. In it was the proposed formation of the Canadian Forest Biorefining Network as well as a parallel Canadian University Forest Biorefining Network. It also identified who could do the RD&D work within the academic community and the Institutes; and organized this Symposium. A subsequent announcement two days later by NRCan Minister Gary Lunn confirmed that substantial funding for this effort would be forthcoming.
Antoine Baril (Cascades) is a man on a mission. He directs an energy reduction program for the company’s 120 plants with a 3%/y cost savings target for their $428million/y energy bill. Much of this careful transformation involves renewables, with biomass and syngas substitutions for fossil fuels. He described the new biogas burner/fluid bed reformer installed at Trenton mill, a technology they wish to use for a wider range of low grade feedstock. Ethanol, biodiesel, hydrogen and hybrid vehicles are all part of the Cascades energy strategy, a well presented example of a company-wide energy plan.
Thermochemical conversion systems for biomass were described in three presentations. Phil Beaty (Nexterra) showed a commercial-scale gasifier system designed especially for hog fuel conversion. The low-particulate, dilute syngas output is used to partially or fully displace natural gas in kilns, driers and steam boilers. A different process, fast pyrolysis using a transported fluidized bed for fast heat addition, was the subject of two further presentations.
Garth Gorsky (Ensyn) showed commercial scale plants converting 40 and 100t/d clean wood-waste into bio-oil, a product that can be made into food additives, specialty chemicals and fuels, or combusted for heat. Colin McKerracher (Dynamotive) presented their version of fast pyrolysis, with a 100t/d operating plant which features electric power cogeneration, and one using 200t/d biomass to start up this year, producing a mixture of bio-oil and char as a heavy oil substitute. Although these pyrolysis plants use mostly uniform white wood as feedstock, they are keen to utilize a wide range of biomass waste. These very encouraging Canadian developments prompted a great deal of interest and many questions from the audience.
Two university presenters gav
e more details of biomass gasification and pyrolysis. Esteban Chornet (University of Sherbrooke) summarized syngas production technologies and showed a 100,000 t/y municipal waste gasifier he is currently designing for Novera Energy for London (UK). Modeling fluid bed reactions is what Jamal Chaouki (cole Polytechnique) does for a living, and he gave us a fascinating glimpse into this fast-changing environment. Radioactive tracers help unlock the ‘ergodic’ mysteries of reactor design. The one underlying message from these presentations was that the critical technology issues for any thermochemical process are the requirements for feedstock quality (white wood, bark, particle size, uniformity, moisture…) and product quality (calorific value, tar and char issues, ash control…). A successful commercial operation must readily transform the available feedstock into a product for immediate use with minimal reprocessing.
Availability of forest biomass was a topic addressed by Christian Messier (Universit de Montral Qubec). He gave a refreshing new vision for forestry in Canada, advocating a blend of conservation and tree farming in place of traditional forest management. His central point was that by zoning areas for either parks (12+ %), ecosystem management (60% to 80%), traditional intensive forestry (5% to 20%) or super-intensive forestry (1% to 5%), the boreal forest would be more productive and better protected. In one of his examples, bigger protected areas were balanced by areas of intensive forestry, with a net 40% gain in growth and yield. In wood-short Quebec, it was no surprise that audience questions had the theme of “what are we waiting for?”
Economic collection of forest biomass was addressed by Mark Ryans (Feric), a topic of renewed interest everywhere with the anticipated new demand from biorefineries. For cut-to-length harvesting, one challenge will be in adapting the latest European technology for Canadian conditions. For full-tree harvesting, optimizing the recovery of roadside waste is the issue, where grinding and transport costs can add a big $40/t cost. Whilst low bulk density, moisture and contaminants control are significant challenges, it is widely appreciated that forest residue must meet hard cost constraints on delivered cost to have any value.
Co-production of pulp and ethanol attracts a lot of attention because transportation fuel is such a huge market. Jim Frederick (Georgia Tech) gave an update on extracting fermentable hemicellulose in an existing mill prior to chemical pulping. His recent experimental work showed that acid pretreatment can also extract some cellulose from loblolly pine chips. He found that cellulose or pulp yield loss raises the required break-even price for ethanol from $US 1.54/USG to as high as $US 2.33/USG, too high to be competitive with corn-based ethanol. He concluded that co-production of pulp and ethanol can be competitive, provided there is minimal cellulose loss.
Later, Adriaan van Heiningen (University of Maine) showed that if preextraction of hemicellulose is done with a pinch of anthraquinone and just enough alkali to neutralize the wood acids, then yield loss can be minimized. He called it ‘Near-Neutral Extraction,’ and showed that pulp properties are unaffected, at least for that well known genus “Southern mixed hardwood.” Tests also showed that oriented strand board strands can also be preextracted, though the resulting board has lower internal bond strength.
An ethanol/sulphite process — the AVAP process — was described by Theodora Retsina (American Process) for energy self-sufficient co-production of softwood pulp, ethanol and lignin. Engineering design is underway for a pilot plant for Flambeau River in the US. The production cost for ethanol was projected to be as low as $US 0.62/USG. In response to a question, Retsina said that the process does not make kraft pulp, a significant concern for Canadian producers who must deliver strong kraft market pulps.
Yaman Boluk (Alberta Research Council) reviewed mostly non-alcoholic chemical products that could be derived from hemicellulose. He sped over the full range of possible processing methods including separations, chemical reactions in media, at interfaces and with catalysts, as well as integration with petrochemicals. The bottom line here is that there is a world of chemical possibilities for hemicellulose utilization, and the challenge is to identify which will be money makers.
Paul Stuart (cole Polytechnique) described methodology for identifying promising forest biorefinery products. He pointed out that product-centric thinking is now needed, very different from the process-centric commodity thinking used for pulp and papermaking. It will mean that the role of R&D will be much more closely linked with marketing and strategy. He suggested that a biorefinery is likely to be unique to every mill as companies balance local feedstock quality, process design options and market opportunities. Flexibility was seen to be essential to allow timely readjustment of the product mix to maximize returns, a sentiment which echoed earlier comments by Tom Gale on how the Temiscaming biorefinery is run. Stuart’s recipe for success: plan the transformation to the forest biorefinery; implement the necessary knowledge-based systems; explore product opportunities; identify sources of forest carbon; and focus on energy efficiency.
Grant Allen (University of Toronto) had a useful perspective on waste treatment systems: in the future they will become production facilities. He gave examples. Anaerobic treatment of wastewater or solids is commercially available technology for methane utilization in a mill/biorefinery. Bio-solids and sludge could be used for production of useful polymers and material, such as the Poly (3-hydroxyalkanoates) or PHA biopolymers already produced in significant quantities in secondary treatment systems. Bio-filtration is a low energy treatment for air emissions, and activated carbon for treatment of air emissions and wastewater can be made from pulp mill bio-solids.
Warren Mabee (UBC) spoke on International Lessons from Biorefining Platform Development. In giving examples of top-down policy with typical targets, mandates and tax exemptions, and bottom-up policies with private/public partnering for example, he was of the opinion that the best way forward was a three step combination approach: first create markets e.g. with incentives; next develop capacity; and lastly, enforce consumption with a top-down mandate. He highlighted the promising US biofuel policy to create and stabilize a large new market for ethanol. In answer to a question, Mabee commended Canadian suppliers for developing new commercial technologies for cellulose fermentation, steam explosion, lignin extraction, pyrolysis and syngas.
C.-J. Li (McGill) talked about the Green Chemistry movement which was prompted by the 1990 US Pollution Prevention Act with its vision of industrial processes without waste. Today’s chemical technology has its origins in processing coal-tar in the 19th century, and petroleum in the 20th century. Biomass will be the next major feedstock. He identified two new aspects of green chemistry for biorefineries: separations technologies using supercritical CO2, ionic liquids and membranes, with a focus on reactions in water; and chemistry to utilize renewable resources directly in their natural states. His big message was that the chemical industry of the future will be fed by biomass.
So after 22 presentations and two full days of sessions, the attendees went away with their heads full of wonderful dreams and schemes to stave off global warming, a much needed distraction on a cold Montreal evening. The minister’s announcement during the conference of major research funding from the federal government will mean that a substantial new initiative on Transformative Technologies can now go ahead, coordinated through FPInnovations and PAPIER. Perhaps we wi
ll look back in a decade and recognize this week as a tipping point, when the industry took the first steps to transform itself with a new approach to technology.
This summary of the Biorefinery Symposium was produced on behalf of Papier, the Canadian Pulp and Paper Network for Innovation in Education and Research. The presentations from these sessions can be found on the PAPTAC website www.paptac.ca
Andy Garner is Principal of Andrew Garner and Associates Inc., specializing in pulp and paper technical issues and corrosion. He can be reached at firstname.lastname@example.org
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