Biomass to Syngas: Modified Stoichiometric Thermodynamic Models for Downdraft Biomass Gasification

Abstract

To help meet the global demand for energy and reduce the use of fossil fuels, alternatives such as the production of syngas from renewable biomass can be considered. This conversion of biomass to syngas is possible through a thermochemical gasification process. To design such gasification systems, model equations can be formulated and solved to predict the quantity and quality of the syngas produced with different operating conditions (temperature, the flow rate of an oxidizing agent, etc.) and with different types of biomass (wood, grass, seeds, food waste, etc.). For the comparison of multiple different types of biomass and optimization to find optimal conditions, simpler models are preferred which can be solved very quickly using modern desktop computers. In this study, a number of different stoichiometric thermodynamic models are compared to determine which are the most appropriate. To correct some of the errors associated with thermodynamic models, correction factors are utilized to modify the equilibrium constants of the methanation and water gas shift reactions, which allows them to better predict the real output composition of the gasification reactors. A number of different models can be obtained using different correction factors, model parameters, and assumptions, and these models are compared and validated against experimental data and modelling studies from the literature.

Co-Combustion of Blends of Coal and Underutilised Biomass Residues for Environmental Friendly Electrical Energy Production

“…Guo et al showed that the excessive amount of biomass and coal blends have advantages to the co-combustion process. They reported the optimum blending ratio of 30% for the composite biomass pellets (CBPs) and coal blends [18].…”

“…The European Union has fixed a mandatory target of getting 20% share of renewable resources in the energy mix by 2020 [16]. Among various available renewable resources, such as solar, hydro, and geothermal; biomass presents a viable substitute owing to its availability and capability of meeting diverse energy needs, including electricity generation, vehicle fueling, and domestic heating [17,18]. Biomass is considered to be the fourth largest fuel after coal, oil, and natural gas, and compared to fossil fuels, biomass is termed as carbon-neutral [19,20].…”

Specific and Cumulative Exhaust Gas Emissions in Micro-Scale Generators Fueled by Syngas from Biomass Gasification

“…It is important to prevent an excessive amount of these contaminants from reaching the engine to maintain the operation and endurance of components such as valves, combustion chamber, and pistons [36]. Tar yield depends on the gasifier type [37] and the downdraft reactors produce syngas with a low tar content [38,39] and, therefore, was chosen to implement this very simple filtration stage. The fuel tank was removed from the generator for safety reasons.…”

Performance Optimization of the Gasification Process by using Equilibrium Model and Dragonfly Algorithm

“…Tauqir et al [10] modelled the gasification process through equilibrium approach, using ASPEN Plus software and studied the effect of Tgasification, MC and ϕ on the SC, lower heating value of the syngas (LHVsyngas) along with hot gas efficiency and cold gas efficiency (ηcoldgas). For wood and agricultural based biomasses, Ayub et al [11] improved the equilibrium model 115-2 by adding correction factors based on the experimental data into the design equations. Caglar et al [12] calculated the variation of the production of syngas yield, hydrogen production, methane production, carbon dioxide emission and gasification efficiencies with respect to Tgasification and different gasifying agents.…”