Department of Chemical Engineering
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Item Advances in Downdraft Biomass Gasification( Nova Science Publishers, 2010) Sheth, P.N.Item Power Generation from Biomass Gasification: A Renewable Energy Source based Technology(Electrical India, 2009) Sheth, P.N.Item Experimental studies on producer gas generation from wood waste in a downdraft biomass gasifier(Elsiever, 2009-06) Sheth, P.N.A process of conversion of solid carbonaceous fuel into combustible gas by partial combustion is known as gasification. The resulting gas, known as producer gas, is more versatile in its use than the original solid biomass. In the present study, a downdraft biomass gasifier is used to carry out the gasification experiments with the waste generated while making furniture in the carpentry section of the institute’s workshop. Dalbergia sisoo, generally known as sesame wood or rose wood is mainly used in the furniture and wastage of the same is used as a biomass material in the present gasification studies. The effects of air flow rate and moisture content on biomass consumption rate and quality of the producer gas generated are studied by performing experiments. The performance of the biomass gasifier system is evaluated in terms of equivalence ratio, producer gas composition, calorific value of the producer gas, gas production rate, zone temperatures and cold gas efficiency. Material balance is carried out to examine the reliability of the results generated. The experimental results are compared with those reported in the literature.Item Thermo-Chemical Conversion of Jatropha Deoiled Cake: Pyrolysis vs. Gasification(IJCEA, 2015-10) Sheth, P.N.Pyrolysis and gasification of biomass is considered to be the promising alternative solutions for the increase of energy demand and environmental awareness. Pyroysis process produces a variety of chemicals by limited degradation and gasification process leads to complete breakdown of the biomass into permanent gases. By gasification, solid biomass is converted into a combustible gas mixture normally called “Producer Gas” consisting primarily of hydrogen and carbon monoxide, with lesser amounts of carbon dioxide, water, methane, higher hydrocarbons, nitrogen and particulates. Whereas the pyrolysis process produces a mainly three types of products: solid (charcoal), liquid (tar and other organics) and gaseous products. In the present study, Jatropha de-oiled cake is taken as a biomass. The pyrolysis and gasification experiments are carried out for comparing the results. The biomass is pyrolyzed in a fixed bed reactor in a Nitrogen environment as well used to produce the producer gas in a fixed bed downdraft biomass gasifier.Item Biomass gasification models for downdraft gasifier: A state-of-the-art review(Elsiever, 2015-10) Sheth, P.N.Among the different methods of energy production from biomass, gasification is considered as the most suitable option as it is a simple and economically viable process to produce thermal energy or decentralized electricity generation. Downdraft gasifiers are typically small-scale units having maximum power production capacity up to 5 MW. This feature makes it more suitable for decentralized power generation and distribution to the remote villages/islands deprived of grid electricity. Mathematical models can be helpful for the design of gasifiers, prediction of operational behavior, emissions during normal conditions, startup, shutdown, change of fuel, change of loading, and to alleviate the type of problems mentioned above. It has been observed that although many researchers have developed models of various types and degrees of complexity, reviews of these modeling and simulation studies are scarce. Largely, it is observed that the review articles reported in the literature fail to address the basic understanding of each model types and their applicability to design different gasifiers for a certain feedstock and variation of operating parameters. This review article discusses different models available for downdraft gasifiers such as thermodynamic equilibrium, kinetic, CFD, ANN and ASPEN Plus models. A comparative analysis of each model and its output is carried out. A critical analysis of the effect of different modeling parameters and finally the advantages and disadvantages of each modeling technique is outlined.Item Recent progress in thermochemical techniques to produce hydrogen gas from biomass: A state of the art review(Elsiever, 2019-10-04) Sheth, P.N.The present work comprehensively covers the literature that describes the thermochemical techniques of hydrogen production from biomass. This survey highlights the current approaches, relevant methods, technologies and resources adopted for high yield hydrogen production. Prominent thermochemical methods i.e. pyrolysis, gasification, supercritical water gasification, hydrothermal upgrading followed by steam gasification, bio-oil reforming, and pyrolysis inline reforming have been discussed thoroughly in view of the current research trend and latest emerging technologies. Influences of important factors and parameters on hydrogen yield, such as biomass type, temperature, steam to biomass ratio, retention time, biomass particle size, heating rate, etc. have also been extensively studied. Catalyst is a vital integrant that has received enough attention due to its encouraging influence on hydrogen production. Literature confirms that hydrogen obtained from biomass has high-energy efficiency and potential to reduce greenhouse gases hence, it deserves versatile applications in the coming future. The study also reveals that hydrogen production through steam reforming, pyrolysis, and in-line reforming deliver a considerable amount of hydrogen from biomass with higher process efficiency. It has been identified that higher temperature, suitable steam to biomass ratio and catalyst type favor useful hydrogen yield. Nevertheless, hydrogen is not readily available in the sufficient amount and production cost is still high. Tar generation during thermochemical processing of biomass is also a concern and requires consistent efforts to minimize it.