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Ethanol production from biomass-derived pentose sugar challenges the development of low cost technologies to produce 2G ethanol. Although some studies describe ethanol production from yeast, few reports describe its manufacturing from hemicelluloses sugars in stirred-tank fermenter under controlled conditions. Experimental assays were performed to evaluate the influence of aeration, agitation rate and initial pH on ethanol production using sugarcane bagasse hemicelluloses hydrolysate by Scheffersomyces stipitis NRRL Y-7124 and Scheffersomyces shehatae UFMG HM 52.2. Ethanol production from these two yeasts was favored by initial pH increase and agitation rate decrease. The maximum fermentative yield was attained by S . stipitis and S . shehatae yeasts at 100 RPM, initial pH 6.50 and under oxygen limited conditions (0.1 and 3.2 h −1 ). Yield, ethanol productivity and process efficiency in S . shehatae and S . stipitis were 0.42 and 0.16 g g −1 , 0.25 and 0.1 g L −1 h −1 and 85 and 31%, respectively. It showed that S . shehatae presented the best ethanol production performance. The current study is the first report describing the influence of these variables on hemicelluloses hydrolysates under controlled conditions. It highlights these xylose-fermenting yeasts potential to produce ethanol from biomass. [ABSTRACT FROM AUTHOR]

Biodiesel production from Mucor circinelloides biomass was investigated by conventional method involving the lipid extraction using ethanol followed by transesterification (two-step process) in comparison with directly producing from the whole biomass without extraction (one-step process). Both processes used solid heteropolyacid catalyst (12-molybdophosphoric acid (H 3 PMo 12 O 40 ) support on alumina (Al 2 O 3 ) under conditions previously set up (200 °C for 4 h). Either one or two-step process was able to convert the microbial lipids into ethyl esters (FAEE) with high yields (97%), though the former simplifies the production process due to the elimination of an oil extraction step that incurs oil loss. Moreover, to minimize the energy used for dewatering, this method can be also used for transesterification of wet M. circinelloides biomass. Direct transesterification of wet biomass greatly simplifies the process of FAEE production by eliminating the drying and oil extraction steps, making this a renewable and environmental friendly process. [ABSTRACT FROM AUTHOR]

Highlights: [•] TLS permit to attain conductivity and thermal diffusivity of biofuels. [•] Diffusivities and viscosities were correlated to attain oil/ biodiesel Pr numbers. [•] Thermal diffusivity changed as a function of iodine index value. [•] Thermal diffusivity of biofuels is important to modeling combustion problems. [•] TLS is unconventional tool to qualify the quality of biodiesel. [ABSTRACT FROM AUTHOR]