Environmental Engineering Reference
In-Depth Information
4. Commercialization
4.1. Cellulases
Although many commercial preparations of cellulase exist, costs have remained high
because present applications are in higher-value markets (food and clothing) than fuels. In
addition, these applications typically require much less than 100 percent cellulose hydrolysis,
in contrast to ethanol production; much improvement is therefore needed to advance the
current cellulase enzyme industry to the point at which it can support the fuel ethanol
industry. As a result, many fuel ethanol commercialization efforts are choosing to use acid
hydrolysis techniques for cellulose hydrolysis until cellulase preparations become less
expensive or until recombinant microbes capable of combined cellulolysis and fermentation
are perfected [3]. Toward this goal, the DOE biofuels program is working with the two largest
global enzyme producers, Genencor International and Novozymes Biotech Incorporated, to
achieve a 10-fold reduction in cost of cellulases [3]
4.2. Ethanol Plants
The first dedicated large-scale plants for the conversion of waste biomass to ethanol are
now in planning and/or construction phases by BCI and the Masada Resource Group
(www.masada.com), while Iogen Corporation (www.iogen.com) is currently operating a 50
ton per week pilot plant. BCI and the DOE Office of Fuels Development have formed a cost-
shared partnership to develop a biomass-to-ethanol plant intended to produce 20 million liters
of ethanol per year initially from sugar cane waste (bagasse) and other biomass, utilizing an
existing ethanol plant in Jennings, LA. Dilute acid hydrolysis will be used to recover sugar
from bagasse initially, allowing for addition of enzyme hydrolysis when cellulases become
less expensive. A proprietary genetically-engineered microbe will ferment the sugars to
ethanol. BCI is also planning to operate a plant in Gridley, CA, in which cellulases will be
used in conversion of commercial rice straw to ethanol, again with partial DOE support.
The Masada plant is expected to produce 9.5 million gallons from municipal solid waste
using Masada's patented CES OxyNolTM concentrated acid hydrolysis technology in New
York [3].
Petro-Canada, the second largest petroleum refining company in Canada, began to co-
fund research and development on biomass-to-ethanol technology with Iogen in 1997. Petro-
Canada, Iogen, and the Canadian government then began plans to fund construction of a
demonstration plant based on Iogen's cellulase enzyme technology in an SSF process [3]. The
plant of Iogen, a leading producer of cellulases, has completed a 40 ton per day biomass-to-
ethanol demonstration facility that is now in its start-up phase [5].
In the pulp and paper industry, Tembec and Georgia Pacific are using dilute acid
hydrolysis to dissolve hemicellulose and lignin from wood, producing a cellulose pulp that
can be fermented to ethanol. The lignin is then used to generate energy, through combustion,
or converted to other products such as concrete additives and soil stabilizers [3].
Pursuing the gasification and syngas-to-ethanol fermentation, BioEngineering Resources,
Inc. (BRI) has developed syngas technology to the extent that plans are underway to pilot the
technology as a first step toward commercialization. BRI has developed bioreactor systems
for fermentation that result in retention times of minutes or less, yielding low equipment costs
[3].
