Aphios granted patent for cellulosic biomass pretreatment

By Aphios Corp. | January 10, 2014

Aphios Corp. has announced that it was granted U.S. Patent No. 8,540,847 entitled “Methods and Apparatus for Processing Cellulosic Biomass,” for its Aosic enabling technology platform.

Cellulosic biomass resources are currently greatly underutilized in the United States and countries around the world. If effectively exploited, these resources can reduce climate change while alleviating several environmental problems. Trevor P. Castor, inventor of the Aosic platform, states that, “Cellulosic biomass is tightly wound for obvious mechanical strength reasons. In order to breakdown cellulose into its individual sugar molecules, cellulosic biomass must be expanded to enhance the access of enzymes that cleave the polymeric bonds between individual sugar molecules.”

Currently, steam explosion is one of the most promising methods of expanding cellulosic fibers. However, this process has several disadvantages including degradation of cellulose and hemicelluloses at the high temperatures utilized and the generation of byproducts that are toxic to cellulosic degrading enzymes. As a result, stem explosion treated wood must be washed after pretreatment. The process is thus both energy and water intensive.

In the Aosic process, biomass is contacted with SuperFluids such as carbon dioxide with or without small quantities of polar cosolvents 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. Additional fiber separation is achieved by ejecting biomass through mechanical impact devices. Carbon dioxide is recovered and recycled; pressure energy is recovered in a turbine.

Castor points out that “Carbon dioxide is consumed in the Aosic process which is a net consumer of carbon. It also utilizes significantly less water than steam explosion and the dilute acid pre-hydrolysis pretreatment processes. It can be used for wood cuttings, bagasse, newsprint, corn fodder and spent biomass from the manufacturing of pharmaceuticals and nutraceuticals.” He continues that “While the primary potential application is pretreating biomass waste for conversion into ethanol and other wood-based chemicals, there are several other potential applications such as newsprint recycling.”