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This work examines some aspects of sugarcane bagasse pyrolysis. Fixed bed pyrolysis was performed varying the final process temperature. Product yields and the variation of quality properties (calorific values) of bio-oil, biochar, and non-condensable gas were investigated. A mathematical model to simulate the trend of temperature that maximizes a marginal gain was developed considering the regression equations for yields and prices of products (related to market prices and calorific value of conventional fuels) and for the amount of biomass used to supply energy to the process. Two methodologies were adopted to calculate the optimum process temperature. The results showed very close temperatures (600 and 602 8C) for the best performing simulations of endogenous and fixed prices methods, with little difference between the yields of products, but with good variation between the marginal gains ($124.9/tonne and $129.8/tonne). Finally, the results of endogenous prices method for the fixed bed reactor were compared to the vacuum and fast pyrolysis reactors.

The microbial populations of an upflow anaerobic sludge blanket reactor, used for treating wastewater from the gelatin industry, were studied by microbiological methods and phase-contrast and electron microscopy. Microscopy examination of the sludge showed a complex mixture of various rod-shaped and coccoid bacterial pluslong filaments and verymobile curved rods. In addition free-living anaerobic ciliates and flagellates were also observed. The trophic group population observed in decreasing order of dominance were hydrolytic and acetogenic at 10(6) and sulfate reducing and methanogenic at 10(5). The rate of methane production in anaerobic granular sludge cultivated in growth medium supplement with formate pressurized with H2:CO2 showed a significant increase in methane yield compared with theseed culture containingthe same substrate and atmosphere of N2:CO2. Similar rates of methane production were observed when the growth medium was supplemented with acetate pressurized either with H2:CO2 or N2:CO2. The number of total anaerobic bacteria at 10(7), fecal coliforms and total coliforms at 10(6), and fecal streptococci at 10(3) is based on colony counts on solid media. The four prevalent species of facultative anaerobic gram-negative bacteria that belong to the family of Enterobacteriaceae were identified as Escherichia coli, Esherichia fergusonii, Klebsiella oxytoca, and Citrobacter freundii. The species Aeromonas hydrophila, Aeromonas veronii, Acinetobacter iwoffi and Stenotrophomonas maltophila were the most frequently isolated glucose fermenting and nonfermenting gram-negative bacilli.