(226d) Abengoa Bioenergy New Technologies Development of Enzymatic Cellulosic Ethanol

Authors: 
Wooley, R. - Presenter, Abengoa Bioenergy


Abengoa Bioenergy, a subsidiary of Abengoa, S.A. is one of the largest producers of bioethanol in the world with capacity in the U.S., Europe and Brazil. The research organization of Abengoa Bioenergy, Abengoa Bioenergy New Technologies (ABNT) is currently developing the 2nd generation technology, lignocellulose conversion to bioethanol and other bioproducts. ABNT is pursuing both the enzymatic conversion of cellulosic feedstocks to fermentable sugars and subsequent fermentation to products and the thermochemical route to syngas and catalytic conversion to products.

The enzymatic conversion process selected by ABNT is based on dilute acid pretreatment, followed by enzymatic hydrolysis and finally fermentation. ABNT is utilizing a strategy of key technology development partnerships and internal development. As an example, in partnership with Dyadic, considerable advances have been made in the efficacy of the cellulase systems based on their patented Chrysosporium lucknowense fungus, known as C1, and in partnership with Cargill, the ethanol fermentation capabilities have been greatly advanced using industrially robust and proven yeast that can currently consume the hexose and xylose sugars. Internally, ABNT has constructed a 1 tonne/day pilot plant in York, NE. This pilot facility has enabled ABNT to study multiple configurations of pretreatment and various strategies of process configuration with respect to the arrangement of fermentation and saccharification. Feedstocks that have been investigated in the York facility include wheat straw, corn stover and various perennial grasses.

Simultaneously to building the York pilot plant, ABNT constructed a demonstration facility in Salamanca, Spain. The process utilized in this demonstration was less flexible than the pilot plant and utilizes one variation of the many considered in the pilot plant. This process consists of the same general unit operations of pretreatment, enzymatic saccharification and fermentation and has a capacity of 70 tonne/day of straw. Valuable information about the handling of solids and their conversion in a near plant scale environment has complemented the laboratory and pilot work conducted.

ABNT has combined work with key partners, its own work with the pilot plant in York and the demonstration facility in Salamanca with Aspen based economic evaluation to develop a first-of-a-kind commercial scale facility scheduled to begin construction in early 2010. This facility to be located in Hugoton, KS is Abengoa Bioenergy's first step in its long term strategy to commercialize this technology as hybrid facilities along with biopower or existing corn (starch) ethanol facilities and then move to stand alone ethanol production and finally biorefineries with multiple products.

The Hugoton facility, known as Abengoa Bioenergy Hybrid of Kansas (ABHK) received a financial assistance award from the U.S. Department of Energy of $76,000,000. The total capital cost of the facility is expected to be about $450,000,000. With construction starting in the first half of 2010, start-up will be in early 2012. The Hugoton site was selected based on the significant supply of biomass and the strong state and local support for the project.

The process will consume about 2,500 tons per day of various biomass feedstocks (82% corn stover, 7% straw, 7% milo stubble and 4% switchgrass) and produce 70 MW of biopower, 16,000,000 gallons of ethanol and 29,000 tons of lignin per year. Six hundred tons per day of corn stover will be utilized for the enzymatic conversion to ethanol.

The technology to be employed at ABHK will consist of dilute acid pretreatment, enzymatic saccharification and fermentation of hexose sugars and xylose. Cargill is a partner in the development of the ethanologen. The harvest radius will be about 50 miles from the plant and consume about 10-12% of the available feedstock. ABHK will use a system of satellite depots for storage and collect the feedstock in two windows, one for wheat straw and one for corn stover and milo stubble.

The facility will create about 45 full time jobs at the facility, 50-100 jobs in biomass procurement, 88 jobs during construction (18 months) and about $9,000,000 to producers for feedstock per year.

With the engineering design of its first-of-a-kind facility in Hugoton, KS completed, ABNT has begun an effort to further refine the design for the future plants. Aspen based economic evaluations and experimental planning has begun to further reduce the cost of cellulosic conversion. Key focus areas are feedstocks (switchgrass and other perennial grass will be more sustainable, reliable and cost effective when available), the high capital costs of pretreatment, effective and efficient enzymatic saccharification and fermentation with the latest enzymes and ethanologens, production of other high value chemicals and the best utilization of lignin to high value products.

Research, key partnerships, project development and operational experience at pilot, demonstration and commercial scales are enabling Abengoa Bioenergy to accomplish its strategic plan to deploy enzymatic cellulosic conversion to ethanol and chemicals through hybrid facilities (co-locating with existing starch ethanol facilities or biopower) and eventually stand alone biorefineries.