Biofuel production from acid-impregnated willow and switchgrass

As part of a broader technical and economic feasibility study, we studied production of bioethanol from two types of lignocellulosic biomass by way of concentrated acid impregnation at low temperature. Willow chips and switchgrass were submitted to various impregnation techniques with concentrated sulfuric acid at varying acid: biomass ratios and impregnation times. Goal of the experiments was to investigate the technical feasibility of concentrated acid pretreatment technology as part of an industrial process that employs recycling of acid through biological means. Experimental results showed that significant amounts of fermentable sugars including glucose (up to 78 f max. obtainable glucose) and xylose can be obtained by relatively simple impregnation techniques at room temperature. Fermentation of willow-derived hydrolysates with S. Cerevisiae yielded 0.45 - 0.49 g ethanol/g glucose. Ethanol production rates however were 38 ower compared to standard glucose fermentation, prompting the need for further optimization to reduce the formation of acetic acid and furfural, two fermentation inhibitors. Novel impregnation techniques, including employment of sulfur trioxide, were also investigated but require more work to assess technical feasibilit

Process and apparatus for conversion of biomass

The invention is directed to a process for the conversion of cellulosic biomass, in particular lignocellulose-containing biomass into fermentable sugars. The invention is further directed to apparatus suitable for carrying out such processes. According to the invention biomass is converted into fermentable sugars by contacting in a reactor said biomass with an acid, while passing an inert gas stream capable of taking up water through said reactor, by which the pH in said reactor can be controlled

Pre-treatment of ligno-cellulose with biological acid recycling (the Biosulfurol process)

A biomass pretreatment process is being developed based on contacting ligno-cellulosic biomass with 70% sulphuric acid and subsequent hydrolysis by adding water. In this process, the hydrolysate can be fermented yielding ethanol, while the sulphuric acid is partly recovered by anion-selective membranes before the fermentation process, and partly via biological sulphate reduction in the anaerobic wastewater treatment plant. The produced sulphide is recovered as H2S gas and chemically converted (burned) into SO 2 and SO3 (by which heat is recovered as well) and subsequently into sulphuric acid. In this unique approach, the sulphuric acid is recycled to a large extent. This process, the Biosulfurol process, is able to handle a wide variety of ligno-cellulosic biomass and does not need the addition of enzymes. In the project switchgrass, willow wood and bagasse are tested as model substrates. The utilization of bagasse can be of interest for the sugar industry and the production of monosaccharides can be regarded as an alternative way to produce sugars from sugarcane residues

Process and apparatus for conversion of biomass

The invention is directed to a process for the conversion of cellulosic biomass, in particular lignocellulose-containing biomass into fermentable sugars. The invention is further directed to apparatus suitable for carrying out such processes. According to the invention biomass is converted into fermentable sugars by contacting in a reactor said biomass with an acid, while passing an inert gas stream capable of taking up water through said reactor, by which the pH in said reactor can be controlled

Pre-treatment of ligno-cellulose with biological acid recycling (the Biosulfurol process)

A biomass pretreatment process is being developed based on contacting ligno-cellulosic biomass with 70% sulphuric acid and subsequent hydrolysis by adding water. In this process, the hydrolysate can be fermented yielding ethanol, while the sulphuric acid is partly recovered by anion-selective membranes before the fermentation process, and partly via biological sulphate reduction in the anaerobic wastewater treatment plant. The produced sulphide is recovered as H2S gas and chemically converted (burned) into SO 2 and SO3 (by which heat is recovered as well) and subsequently into sulphuric acid. In this unique approach, the sulphuric acid is recycled to a large extent. This process, the Biosulfurol process, is able to handle a wide variety of ligno-cellulosic biomass and does not need the addition of enzymes. In the project switchgrass, willow wood and bagasse are tested as model substrates. The utilization of bagasse can be of interest for the sugar industry and the production of monosaccharides can be regarded as an alternative way to produce sugars from sugarcane residues

De reductie van ijzererts in een gefluidiseerd bed

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Biofuel production from acid-impregnated willow and switchgrass

As part of a broader technical and economic feasibility study, we studied production of bioethanol from two types of lignocellulosic biomass by way of concentrated acid impregnation at low temperature. Willow chips and switchgrass were submitted to various impregnation techniques with concentrated sulfuric acid at varying acid: biomass ratios and impregnation times. Goal of the experiments was to investigate the technical feasibility of concentrated acid pretreatment technology as part of an industrial process that employs recycling of acid through biological means. Experimental results showed that significant amounts of fermentable sugars including glucose (up to 78 f max. obtainable glucose) and xylose can be obtained by relatively simple impregnation techniques at room temperature. Fermentation of willow-derived hydrolysates with S. Cerevisiae yielded 0.45 - 0.49 g ethanol/g glucose. Ethanol production rates however were 38 ower compared to standard glucose fermentation, prompting the need for further optimization to reduce the formation of acetic acid and furfural, two fermentation inhibitors. Novel impregnation techniques, including employment of sulfur trioxide, were also investigated but require more work to assess technical feasibilit