YEAR 2 BIOMASS UTILIZATION

Abstract

This Energy & Environmental Research Center (EERC) Year 2 Biomass Utilization Final Technical Report summarizes multiple projects in biopower or bioenergy, transportation biofuels, and bioproducts. A prototype of a novel advanced power system, termed the high-temperature air furnace (HITAF), was tested for performance while converting biomass and coal blends to energy. Three biomass fuels--wood residue or hog fuel, corn stover, and switchgrass--and Wyoming subbituminous coal were acquired for combustion tests in the 3-million-Btu/hr system. Blend levels were 20% biomass--80% coal on a heat basis. Hog fuel was prepared for the upcoming combustion test by air-drying and processing through a hammer mill and screen. A K-Tron biomass feeder capable of operating in both gravimetric and volumetric modes was selected as the HITAF feed system. Two oxide dispersion-strengthened (ODS) alloys that would be used in the HITAF high-temperature heat exchanger were tested for slag corrosion rates. An alumina layer formed on one particular alloy, which was more corrosion-resistant than a chromia layer that formed on the other alloy. Research activities were completed in the development of an atmospheric pressure, fluidized-bed pyrolysis-type system called the controlled spontaneous reactor (CSR), which is used to process and condition biomass. Tree trimmings were physically and chemicallymore » altered by the CSR process, resulting in a fuel that was very suitable for feeding into a coal combustion or gasification system with little or no feed system modifications required. Experimental procedures were successful for producing hydrogen from biomass using the bacteria Thermotoga, a deep-ocean thermal vent organism. Analytical procedures for hydrogen were evaluated, a gas chromatography (GC) method was derived for measuring hydrogen yields, and adaptation culturing and protocols for mutagenesis were initiated to better develop strains that can use biomass cellulose. Fly ash derived from cofiring coal with waste paper, sunflower hulls, and wood waste showed a broad spectrum of chemical and physical characteristics, according to American Society for Testing and Materials (ASTM) C618 procedures. Higher-than-normal levels of magnesium, sodium, and potassium oxide were observed for the biomass-coal fly ash, which may impact utilization in cement replacement in concrete under ASTM requirements. Other niche markets for biomass-derived fly ash were explored. Research was conducted to develop/optimize a catalytic partial oxidation-based concept for a simple, low-cost fuel processor (reformer). Work progressed to evaluate the effects of temperature and denaturant on ethanol catalytic partial oxidation. A catalyst was isolated that had a yield of 24 mole percent, with catalyst coking limited to less than 15% over a period of 2 hours. In biodiesel research, conversion of vegetable oils to biodiesel using an alternative alkaline catalyst was demonstrated without the need for subsequent water washing. In work related to biorefinery technologies, a continuous-flow reactor was used to react ethanol with lactic acid prepared from an ammonium lactate concentrate produced in fermentations conducted at the EERC. Good yields of ester were obtained even though the concentration of lactic acid in the feed was low with respect to the amount of water present. Esterification gave lower yields of ester, owing to the lowered lactic acid content of the feed. All lactic acid fermentation from amylose hydrolysate test trials was completed. Management activities included a decision to extend several projects to December 31, 2003, because of delays in receiving biomass feedstocks for testing and acquisition of commercial matching funds. In strategic studies, methods for producing acetate esters for high-value fibers, fuel additives, solvents, and chemical intermediates were discussed with several commercial entities. Commercial industries have an interest in efficient biomass gasification designs but are waiting for economic incentives. Utility, biorefinery, pulp and paper, or other industries are interested in lignin as a potential fuel or feedstock but need more information on properties.« less