Readers of this blog know that I have a soft spot for patent PR, particularly green patent PR (see, e.g., here and here). So I’m always interested in covering announcements by green tech companies about their patents.
Aphios, a Massachusetts company that develops technology for cellulosic biomass conversion, recently put out a press release announcing the grant of U.S. Patent No. 8,540,847 (’847 Patent).
Entitled “Methods and apparatus for processing cellulosic biomass,” the ’847 Patent is directed to methods and apparatus for making ethanol or other biofuels using what Aphios calls its Aosic process.
The apparatus (11) described and claimed in the patent comprises a first vessel (13) for receiving cellulosic biomass and conveying means (15) in fluid communication with the first vessel (13). The apparatus (11) also comprises supercritical, critical, or near critical fluid means (17), which includes a source of gas, such as gas tank (41), holding carbon dioxide pressurized to form supercritical, critical, or near critical fluid.
The fluid means (17) is in fluid communication with conveying means (15) via conduit (31). A pump (47) is connected to a heat exchanger (55), which controls the temperature of the supercritical, critical, or near critical fluid.
The cellulosic biomass is loaded into the first vessel (13) and becomes laden with the supercritical, critical, or near critical fluid. Discharge means (21) is in fluid communication with the conveying means (15) for receiving cellulosic biomass laden with the supercritical, critical, or near critical gas and discharging the gas to form a disrupted cellulosic biomass.
A second vessel assembly (23) may include a hydrolysis vessel (23a) and a fermentation vessel (23b) for further processing of the cellulosic biomass. Discharge means (21), including a discharge pipe (71) is connected to a turbine (73), which captures the kinetic energy of the expanding gas. The turbine (73) is coupled to an electric generator to recover and recycle energy from the process.
According to the press release, contacting the cellulosic biomass with the supercritical, critical, or near critical fluid or gas improves the process by separating the fibers of the biomass:
In the Aosic process, biomass is contacted with SuperFluids such as carbon dioxide with or without small quantities of polar solvents such as ethanol, both sourced from the downstream fermentation process. Pressure is released and fibers are made more accessible to enzymes as a result of expansive forces of SuperFluids (about 10 times those of steam explosion) and carbonic acid hydrolysis.
The ’847 Patent says the process provides biomass recovery yields between 95 and 99 percent.
Eric Lane is a patent and trademark attorney and the Principal at Green Patent Law in San Diego and the author of Green Patent Blog. Mr. Lane can be reached at (619) 818-6043 and at elane@greenpatentlaw.com.
