|Flow diagram for Arkenol’s acid-hydrolysis process.|
Nikkei. Japan’s JGC Corp. will work with Arkenol in the US to begin production and sales of fuel ethanol made from scrap wood. The two companies will establish a joint venture before the end of the year with the goal of launching production in 2009.
JGC intends to seek US investors and build a ¥5 billion (about US$43 million) plant in California with a capacity of 30,000 kl (7.9 million gallons US) per year. The Japanese firm will supply technology for construction, design and maintenance. Arkenol holds basic patents on technology to produce bioethanol from waste wood.
JGC is a global engineering firm with a focus on plant design and construction and an emphasis on oil and gas fields and utilities.
Arkenol is a California-based technology and project development company whose focus is the construction and operation of ethanol factories worldwide. The company also licenses its ethanol-producing technology to others.
Arkenol developed and has patented an implementation of concentrated acid hydrolysis for the processing of cellulosic biomass into simple sugars suitable for fermenting into ethanol.
The acid hydrolysis process for alcohol production has been known for more than 100 years, but was characterized by poor yields, high wastage, and a large volume of unmarketable by-products. Arkenol developed methods for efficient acid recovery and reconcentration, and for delivering high sugar concentration at high purity.
Incoming biomass feedstocks are cleaned and ground to reduce the particle size for the process equipment. The pretreated material is dried and then mixed with a solution of about 25-90% acid by weight to at least partially decrystallize the materials and form a gel that includes solid material and a liquid portion.
The gel is diluted to an acid concentration of from about 20–30 wt.% heated to a temperature between about 80–100° C. This partially hydrolyzes the cellulose and hemicellulose contained in the starting materials.
The liquid portion and the solid material are separated, thereby obtaining a first liquid containing sugars and acid. The separated solid material is then run through the same process again, hydrolyzing the cellulose and hemicellulose remaining in the separated solid material and forming a second solid material and a second liquid portion.
The two liquid portions are then combined, and the acids separated from the hexose (C6) and pentose (C5) sugars with an Arkenol-developed technology that uses commercially available ion exchange resins. The resulting solution has a sugar content of at least 15% by weight, and an acid content of not more than 3% by weight.
The separated sulfuric acid is recirculated and reconcentrated to the level required by the decrystallization and hydrolysis steps. The small quantity of acid left in the sugar solution is neutralized with lime to make hydrated gypsum, CaSO4 · 2H2O, an insoluble precipitate which is readily separated from the sugar solution and which also has beneficial use as an agricultural soil conditioner.
US Patent #5,597,714: Strong acid hydrolysis of cellulosic and hemicellulosic materials