Aphios granted US Patent for pretreating cellulosic biomass to manufacture biofuels and biochemicals

Aosic process contacting biomass with SuperFluids to make fibers more accessible to enzymes

Woburn, Mass. – Aphios Corporation today announced that it was granted United States 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 energy and environmental problems. Dr. 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 the most commercially used method for 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 water and energy 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.

Dr. 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 process. It can be used for wood cuttings, bagasse, newsprint, corn fodder and spent biomass from the manufacturing of natural 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.”

About Aphios Corporation
Aphios Corporation, Woburn, MA is developing green, enabling technology platforms for improved drug discovery and manufacturing, nanotechnology drug delivery, pathogenic drug safety, and cellulosic biomass conversion and utilization. This research was supported in part by Grant Number 90-33610-5111 from the United States Department of Agriculture.


Aphios Corporation, press release, 2013-01-08.


Aphios Corporation
US Department of Agriculture (USDA)