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231.
Zsófia Kádár Anne Deen Christensen Mette Hedegaard Thomsen Anne-Belinda Bjerre 《Fuel》2011,90(11):3323-3329
In organic farming, there is a strong effort to minimize the share of non-renewable resources (e.g. fossil fuels) and use only (preferably on-farm produced) bio-based energy and renewable raw materials, with the aim of achieving sustainable production systems and to become self-sufficient in energy.Throughout our studies, wheat and rye grain was used as raw material in bioethanol production with the purpose of producing in situ enzymes (during germination) for the hydrolysis of starch in the grains and compared with commercial amylase enzyme preparations. Whey permeate was incorporated into the grain in Simultaneous Saccharification and Fermentation (SSF) process to use a cheap nutrient and water source. The ethanol fermentations were completed by 190 h. The fermentation efficiency of germinated and un-germinated grains (without commercial enzymes) was compared with that of commercial enzymes in SSF and furthermore Autoamylolytical Quotient (AAQ) was calculated. On rye 72% yield of the theoretical was achieved by applying commercial enzymes, which decreased only by 10%, when in situ enzymes produced during germination were used alone. The obtained ethanol yields and high (90%) AAQ values showed that rye is a suitable substrate for autoamylolytical processes. According to the low yields (<56%) and AAQs values for all examined wheat samples the results implied that the tested sorts of wheat grains were no efficient for use in autoamylolytical processes. 相似文献
232.
Multi-objective regulation in autohydrolysis process of corn stover by liquid hot water pretreatment
Increasing reducing sugars (xylose and glucose) yield for bioethanol from corn stover depends strongly on optimization of pretreatment conditions. The optimumreaction conditions of two-stage liquid hotwater (LHW) pretreatment based on total sugars yield were investigated. Under optimal conditions, the recovery of glucose of corn stover after two-stage LHWpretreatment and 72 h enzymatic digestion, reached 89.55%. In addition, acetic acid-rich spent liquor pretreatment and one-stage LHW pretreatment have been carried out to make comparisons with two-stage LHWtreatment. Glucose yield 89.55% is superior to the recovery 83.38% using acetic acidrich spent liquor pretreatment or 80.58% using one-stage LHW pretreatment. The production of total sugars was increased by 7.8% when compared with one-stage pretreatment. Moreover, the structural features of the treated corn stover solid residueswere also investigated by XRDand SEMtechnology in order to clarify the effects of the reaction on corn stover. The results indicated that the two-stage LHWpretreatment was an effective pretreatmentmethod of corn stover to get most massive resource utilization, and it could be successfully applied to corn stover. 相似文献
233.
This paper deals with design and control of an extractive dividing-wall distillation column (EDWC) for ethanol dehydration using ethylene glycol as entrainer. An initial design, based on a section analogy procedure for a conventional extractive distillation sequence, was obtained and then used in an optimization process to minimize the total annual cost. It was shown that the EDWC can result in significant savings over the conventional process. As these savings sometimes go along with a decrease in the control properties, an investigation of two control structures for the EDWC and one for the conventional column configuration was performed next.It was observed in closed-loop simulations that the EDWC with an appropriate structure exhibited good control properties and that its closed-loop responses were similar to those obtained for the operation of a conventional extractive distillation system. 相似文献
234.
Christiano de C. Lamb Bruna Martini Zacarias da Silva Diego de Souza Franccesca Fornasier Larissa Brixner Riça 《Chemical Engineering Communications》2018,205(6):833-845
The objective of this research was to produce bioethanol from rice hulls and to evaluate the recovery and potential use of the residue resulting from the enzymatic hydrolysis step before fermentation. Acid pretreatment and enzymatic hydrolysis were studied for saccharification of polysaccharides. Fermentation was conducted for up to 24?h with Saccharomyces cerevisiae yeast. After process optimization, it was possible to produce >7.0?mg?mL?1 of ethanol after only 2?h of reaction. Characterization of the solid residues from the hydrolyzed rice husk and the in natura rice husk showed that these solids have different characteristics and present different adsorption potentials because the residue has higher silica content. The product has potential use in industrial or laboratorial adsorption processes. The results from this study offer support for the potential use of rice husks for bioethanol generation and use the solid residue from hydrolysis for adsorption. 相似文献
235.
《International Journal of Hydrogen Energy》2023,48(23):8418-8429
The article considers the possibility of applying the concept of a “transition link” from hydrocarbon to “green” energy. The entire world industry uses hydrocarbons as fuel. The share of “green” energy is growing, but it cannot completely replace oil, gas and coal at this stage. In many production processes, due to technology, a significant amount of heat is lost. Thus, the anthropogenic impact is doubled both due to fuel combustion and due to heat losses into the environment. Traditional methods of reducing harmful emissions, as a rule, are focused only on a specific type of treatment and are capital treatment facilities. The authors' approach to the problem differs from the generally accepted one. The developed method makes it possible to obtain an additional product due to waste heat, while reducing emissions of carbon monoxide into the atmosphere. The authors have chosen Combined heat power plant (CHPP), thermal power plant (TPP) as the object of research. Their role as a source of heat, light and hot water supply can hardly be overestimated. But thermal power plants and thermal power plants are also sources of greenhouse gases generated during fuel combustion, sources of heat loss with exhaust gases and thermal pollution of water bodies with cooling liquid. Thermal pollution of water bodies leads to their overgrowth with algae, and as a result, deterioration of water quality. The method presented by the authors is based on the integrated use of waste heat generated in large volumes in algae cooling ponds and the production of bioethanol. Studies were carried out on a mass spectrometer of the chemical composition of algae formed in various media (sea, tap and purified water). During the experiments, legumes were grown on purified water, tap water, and distilled water. According to the calculations, the cost of 1 L of the resulting bioethanol will be about 28 rubles/l, which is 3 times cheaper than what is currently produced. It is concluded that the polluted water of a thermal power plant or thermal power plant has a negligible effect on the bioethanol yield. A 17.8-fold decrease in sodium was shown due to the use of biofilters. During the experiments, legumes were grown on purified water, tap water, and distilled water.The conclusion is made about the significant adsorption capacity of Zn, Mg, Fe, Al, Si, Pb ions. The resulting water after passing through the algae was tested according to SanPiN 2.1.4.1074-01, and fully complied with the standard, which allows it to be used for technological and technical purposes and, moreover, to be returned to the natural environment without consequences.The work is planned within the framework of an international project to create devices and industrial technology that provides for the production of synthesis gas in a fuel processor and hydrogen for generating electrical energy using a fuel cell. 相似文献