Aphios Corporation

Biomass Pretreatment

Biomass resources are currently greatly underutilized in the United States and countries around the world. If effectively exploited, these resources can reduce our dependency on foreign oil while alleviating several environmental problems.

Forests are prime candidates for improvement in biomass utilization. In the harvesting of a tree, approximately 40% of the biomass is either burned or treated as a waste problem. This waste biomass can be utilized as the feedstock for fermentation processes that could produce ethanol, industrial chemicals and ruminants for animal feed. Ethanol production from plant substrates requires the development of an efficient pretreatment process for increasing the susceptibility of woody biomass to hydrolytic enzymes. Pretreated biomass substrates can then be hydrolyzed to glucose and converted to ethanol by conventional yeast fermentation. Biomass produced ethanol can displace gasoline usage, thereby reducing oil consumption while lowering air pollution.

Currently, steam explosion is one of the most promising methods of pretreating and fractionating woody biomass waste. However, this process has several disadvantages including degradation of cellulose and hemicellulose, loss of brightness, deterioration of fiber strength, reduction in yield and operating cost requirements. Also, the steam explosion pretreatment process may have upper limit pressure constraints that are defined by the maximum allowable saturated steam temperature, which can be utilized without significant product degradation.

Aphios has developed an improved biomass pretreatment process [the CBP process] that has the combined capability to defibrate biomass at low operating temperatures and fractionate wood into its constituents. We have demonstrated that the CBP process is technically feasible with several advantages over conventional steam explosion pretreatment. These conclusions are based on: (1) high enzymatic conversion efficiencies to ethanol (CBP was 60% more effective than steam explosion in pretreating white pine, 300% better in pretreating newsprint and just as effective in pretreating red oak): (2) biomass recovery yields were much higher with CBP (between 95% and 99%) than steam explosion (often less than 80%); (3) operating conditions of temperature and time were lower for CBP than for steam explosion.

The primary potential application for the CBP process is pretreating biomass waste for bioconversion into ethanol and other wood-based chemicals. The use of waste biomass as a cheap raw material for the production of ethanol by bioconversion processes could significantly impact the manufacturing cost of gasohol. There are several other potential applications such as recycling of newsprint, microfibrillation of cellulose as an additive in the food and cosmetic industries, manufacturing improved hardboard and producing “super” pulp while reducing chemical usage and spent liquor generation.