A DECADE OF LIGNOCELLULOSIC BIOPROCESS

DEVELOPMENT: STAGNATION OR CONSOLIDATION?

Iogen’s process in Canada and (insofar as process details can be assessed) from Spanish and other imminent facilities use only a small fraction of the technologies that have been devised for ethanol production from lignocellulosic sources; patents and patent applications covering the last 30 years are exemplified by those listed in table 4.6.

Can any predictions be made about the take-up of innovative process methodolo­gies in the first decade of commercial fuel ethanol production from biomass? Retrac­ing steps across the 10-12 years since the manuscripts were prepared for the 1996 Handbook on Bioethanol publication reveals a significant divergence:

• “Ethanol from lignocellulosic biomass (bioethanol) can now be produced at costs competitive with the market price of ethanol from corn.”320

• “Although bioethanol production is competitive now for blending with gas­oline, the goal of the Department of Energy Biofuels Program is to lower the cost of production to $0.18/l, which is competitive with the price of gasoline from petroleum at $25/bbl with no special tax considerations.”321

• “Despite high capital costs, Charles Wyman of the University of California, Riverside, US, told Chemistry World that cellulose technology could be commercialized now if investors would take the risk or government provide more policy and financial assistance. That breakthrough may happen in the next five years.”322

Despite crude oil prices being considerably higher than $25/bbl since 2002 (figure 1.3), and despite two successive Presidential State of the Union addresses outlining a consistent vision for alternative fuels in the United States, only tax breaks may accelerate cellulosic ethanol production in an uncertain market, or the equivalence between corn and cellulosic ethanol production costs has been broken, or the 1990s may have seen too many overly optimistic forward statements.

Or, the successes of corn and sugar ethanol confused rather than illuminated. Together with biodiesel (a product with a very straightforward technology platform,

Подпись: Date of filing or award September 12, 1997 July 23, 1999 January 11, 2000 November 16, 2001 April 11, 2002 August 27, 2002 November 29, 2005 January 5, 2006 February 2, 2006 May 11, 2006 August 15, 2006 August 17, 2006 TABLE 4.5

Patent Applications and Patents Awarded for Plant Genetic Applications Relevant to Bioethanol Production

Title

Transgenic plants expressing cellulolytic enzymes Expression of enzymes involved in cellulose modification Expression of enzymes involved in cellulose modification

Manipulation of the phenolic acid content and digestibility of
plant cell walls…

Regulation and manipulation of sucrose content in sugarcane
Self-processing plants and plant parts

Genetic engineering of plants through manipulation of lignin
biosynthesis

Manipulation of the phenolic acid content and digestibility of
plant cell walls…

Commercial production of polysaccharide degrading enzymes in
plants…

Modification of plant lignin content

Transgenic fiber producing plants with increased expression of
sucrose synthetase

Подпись: Applicant/assignee Syngenta AG, Basel, Switzerland Calgene, Davis, CA Calgene, Davis, CA Genencor International, Palo Alto, CA F.C. Botha and J.H. Groenewald Syngenta AG, Basel, Switzerland Michigan Technological University, Houghton, MI Genencor International, Palo Alto, CA Applied Biotechnology Institute, College Station, TX ArborGen, LLC Texas Tech University, Lubbock, TX M.S. Sticklen et al. Подпись: Patent/application ЕР 1 574 580 A2 WO 00/05381 US 6013860 WO 02/068666 Al US 2002/0042930 Al WO 03/018766 A2 US 6969784 US 2006/0005270 Al US 2006/0026715 Al US 2006/0101535 Al US 7091400 US 2006/0185036 Al Подпись: Biochemical Engineering and Bioprocess Management for Fuel Ethanol 207Transgenic plants containing ligninase and cellulase…

Подпись: December 25, 2001 February 27, 2002 July 16, 2002 March 6, 2003 April 29, 2003 June 12, 2003 December 9, 2003 April 8, 2004 March 8, 2004 September 9, 2004 TABLE 4.6

Patent Applications and Patents Awarded for Cellulosic Ethanol Technologies

Date of filing or award Title Applicant/assignee

February 22, 1977 Process for making ethanol from cellulosic material using plural Bio-Industries, Inc., Hialeah, FL

ferments

December 9, 1986 Method for the conversion of a P & W substrate to glucose using Parsons and Whittemore, Inc. (NY)

Microspora bispora strain Rutgers P & W

October 10, 2000 Ethanol production using a soy hydrolysate-based medium or a University of Florida, Gainesville, FL

yeast autolysate-based medium

Ethanol production from lignocellulose University of Florida, Gainesville, FL

Method of processing lignocellulosic feedstock for enhanced Iogen Bio-Products Corporation, Ontario,

xylose and ethanol production Canada

Method of treating lignocellulosic biomass to produce cellulose Pure Vision Technology, Inc., Fort Lupton, CO

Organic biomass fractionation process E. S. Prior

Method for processing lignocellulosic material Forskningscenter Riso, Roskilde, Denmark

Methods for cost-effective saccharification of lignocellulosic E. E. Hood and J. A. Howard

biomass

Ethanol production with dilute acid hydrolysis using partially dried Midwest Research Institute, Kansas City, MO lignocellulosics

Recombinant hosts suitable for simultaneous saccharification and University of Florida Research Foundation, Inc. fermentation

Methods to enhance the activity of lignocellulose-degrading Athenix Corporation, Durham, NC

enzymes

Подпись: Patent/application US 4009075 US 4628029 US 6130076 US 6333181 WO 02/070753 A2 US 6419788 US 2003/0041982 A1 US 6555350 US 2003/0109011 A1 US 6660506 US 2004/0067555 A1 WO 2004/081185 A2 US 2004/0176647 A1 Подпись: 208 BiofuelsProcess to extract phenolic compounds from a residual plant Centro de Investigaciones Energeticas, Madrid, material using a hydrothermal treatment Spain

Подпись: July 28, 2005 October 20, 2005 January 12, 2006 April 11, 2006 June 13, 2006 April 3, 2007 June 28, 2007 Procedure for the production of ethanol from lignocellulosic
biomass using a new heat-tolerant yeast

Methods for degrading lignocellulosic materials
Methods for degrading or converting plant cell wall
polysaccharides

Methods for glucose production using endoglucanase core protein
for improved recovery and reuse of enzyme
Methods and compositions for simultaneous saccharification and
fermentation

Upflow settling reactor for enzymatic hydrolysis of cellulose
Pretreatment of bales of feedstock
Methods and processing lignocellulosic feedstock for enhanced
xylose and ethanol production

Centro de Investigaciones Energeticas US 2005/0069998 A1

Medioambientales у Tecnologicas, Madrid,

Spain

Novozymes Biotech, Inc., Davis, CA US 2005/0164355 A1

Novozymes Biotech, Inc., Davis, CA US 2005/0233423 A1

 

Подпись: Biochemical Engineering and Bioprocess Management for Fuel Ethanol 209

D. Wahnon et al.

 

US 2006/008885 Al

 

University of Florida Research Foundation, Inc. US 7026152

 

B. Foody et al.

Iogen Energy Corporation, Ottawa, Canada
R. Griffin et al.

 

US 2006/0154352 Al
US 7198925
US 2007/0148751 Al

 

see chapter 6, section 6.1), conservative technologies proved both profitable and easily scaleable. Biodiesel in particular had the temptation of untapped resources of plant materials (oils) that could, with no time-consuming or costly processing, become a second-generation biofuel after alcohol from sugar and corn.323 Designs of cellulosic ethanol plants still face the crucial problem of choice, especially that of pretreatment technology (section 4.2) for any of the large-scale feedstocks presently under serious consideration — and there may be simply too many possible choices, all supported by published data sets. In addition, there is the question of timing: the marked acceleration and expansion of fuel ethanol production in the United States started in the late 1990s with corn ethanol and has continued with corn ethanol for at least eight years (figure 1.16). In other words, the actual expansion of the industry could have occurred (and did occur) without exhausting the possible supply of corn, the feedstock with, by far, the easiest substrate preparation route before fermentation that could use the existing corn milling infrastructure.

What now (2008) and in the near future? The almost exclusive focus on corn in North America has certainly caused price inflation that has translated to higher feed costs for beef, pork, and chicken that will (as USDA predicts) result in a declin­ing meat supply.324 Higher corn prices have also triggered a tortilla inflation crisis in Mexico, and another USDA prognosis is for a 3.5% annual rise in food prices in 2007. These economic changes will only be exacerbated by a continued expansion of corn ethanol outputs without a massive surge in corn grain yield; lignocellulosics break this vicious cycle, adding diversity to the limited range of substrates but inevi­tably requiring more complex bioprocess technologies — of which the Iogen and Abengoa initiatives represent add-on solutions to existing fuel alcohol production processes. On this analysis, the more advanced process options remain for another five to ten years, and possibly much longer, while investors follow the proven tech­nologies (wheat straw, separate hydrolysis and fermentation, batch or fed-batch fer­mentation), minimizing production costs by sharing facilities with cereal ethanol production: the first cellulosic ethanol facilities in the United States may be opera­tional in 2010, possibly utilizing sugarcane bagasse feedstock, whereas the same recombinant bacterial technologies will be producing 4 million liters of ethanol from demolition wood waste in Japan by 2008 (www. verenium. com).

The step change beyond mixed cereal/cellulosic ethanol has, however, already been extensively discussed, that of the integrated production of biofuel, power, animal feeds, and chemical coproducts to maximize the number of different saleable commodities to supplement or (if need be, under adverse market conditions) supplant bioethanol as the income stream, that is, “biocommodity engineering.”325 Given the availability of large amounts of biomass sources in probably overlapping and complementary forms (thus necessitating flexibility in the production process to utilize multiple substrates on a seasonal basis), biocommodities will become no more of a process and production chal­lenge than are the different alcoholic outputs from most large breweries or, with a chem­ical methodology, those from industrial petroleum “cracking” into petrochemicals.

Investors will nevertheless require convincing of the economic viability of bio­ethanol in the short term, in years where crop yields (corn, wheat, etc.) are better or worse than expected, when farm commodity prices fluctuate, and when interna­tional competition for the most widely sought biofuel feedstocks may have become significant and — most importantly — with or without continued “financial assis­tance” from national governments. The economics of bioethanol will be examined in the next chapter to define the extent of financial subsidies used or that still remain necessary and how high capital costs may inhibit the growth of the nascent industry.