ZeaChem Cellulosic Ethanol Refinery, Oregon, USA

On 2 June 2010, ZeaChem started construction of a biorefinery in Boardman, in the US state of Oregon. It is located at Port of Morrow and is near to Albus tree farms, which will supply feedstock. Upon completion in 2011, the biorefinery will annually produce 250,000gal of cellulosic ethanol.

The biorefinery will use third-generation renewable biomass and convert it into sustainable fuel based on a patented core technology developed by ZeaChem.

The cellulosic ethanol refinery is expected to generate 167 jobs in Boardman and 292 jobs in Oregon.

Design and construction

ZeaChem started preparation of the site in 2008. The biorefinery will have chemical fractionation and hydrogenation process units for ethanol production. Construction of a semi-works scale plant, the front-end fermentation part of the biorefinery, was started in November 2009.

The semi-works scale plant has modular building blocks that will offer operational flexibility and ready integration with the plant. Each cargo container-sized block has individual fermentation process units for the production of fermentation bacteria. The units were built by Hazen Research.

Biorefinery feedstock

In February 2008, ZeaChem signed a long-term agreement with GreenWood Resources (GWR) for the supply of poplar tree feedstock for the biorefinery. The ZeaChem ethanol process also uses herbaceous crops, agricultural residuals, corn stover and switch grass as feedstock. GWR and ZeaChem will also seek the development of short-rotation poplar biomass feedstock integrated with ethanol conversion technology.

Technology

The biorefinery produces cellulosic ethanol using ZeaChem's patented biorefinery process. Unlike traditional processes, the ZeaChem technology is considered to be more economical and produce a higher yield. The hybrid technology is developed by combining thermochemical and biochemical fermentation processes. On 28 June 2010, third-party vendors confirmed that the ethanol biorefining process developed by ZeaChem is scalable to commercial production.

Process technology

The ZeaChem biorefining process uses the rigid structural cellulose and lignin compounds from the feedstock. A cellulose carbon chain-digesting bacteria, acetogen, will be used to convert biomass sugar molecules into acetic acid. The acetogen processing will produce 40% more ethanol for a ton of biomass without any CO2 by-product.

The acetic acid will then be converted to ester, which will be further reacted with hydrogen to produce ethanol. ZeaChem generates the required hydrogen through gasification of lignin residue to create hydrogen-rich syngas. Hydrogen from syngas is used for ester hydrogenation, while the remaining gas is combusted for producing power and steam for the process.

The process is expected to generate about 135gal of ethanol for one bone-dry ton of feedstock. The process is environmentally efficient and economical compared to conventional cellulosic ethanol processes.

The biorefinery's C2 carbon chain suite of products includes acetic acid and ethyl acetate. The company is also planning to develop bio-based chemicals and biofuels, and propionic acid, propanol and propylene.

Contractors and companies

ZeaChem will finance, own and operate the biorefinery. In February 2009, the company awarded an engineering, procurement and construction contract to CH2M HILL. Other companies involved in the project are Hazen Research, Valero Energy and GreenWood Resources.

Financing

ZeaChem received a $25m grant from the US Department of Energy through the 2009 American Recovery and Reinvestment Act. In January of that year the company secured $34m from venture capitalists PrairieGold Venture Partners and Globespan Capital Partners. Follow-on investors will include Firelake Capital, Valero Energy Corporation and MDV-Mohr Davidow Ventures.

Market growth

Ethanol or ethyl alcohol is a fuel additive that is blended with petrol and used as eco-friendly transport fuel. The annual market for ethanol is estimated to be $13.6bn in the US and $26.2bn across the world.