Numerical investigation of sugarcane bagasse gasification using Aspen Plus and response surface methodology

High-Ash Low-Rank Coal Gasification: Process Modeling and Multiobjective Optimization

“…The average RMSE is calculated for dry gas molar compositions of N 2 , H 2 , CO, CO 2 , and the dry gas output (kg/h) as given in Table S3 in the Supporting File. The maximum and minimum RMSE values were found for the dry gas output (kg/h) and H 2 (mol %) as 2.89 and 1.8, 51 and the simulation results of Kombe et al 45 respectively. These RMSE values are perfectly acceptable on the basis of the consideration that the simulation model ignores the reaction kinetics and fluid hydrodynamics inside the gasification system.…”

“…The equilibrium modeling of the coal gasification process in a downdraft fixed-bed gasifier is done based on various assumptions as follows: , The simulation is zero-dimensional, and the reaction processes in coal gasification are assumed to be isothermal and at a steady state. Particle size distribution of the coal is not considered in the simulation. The gasifier unit is assumed to be in a state of thermodynamic equilibrium, which means all the reactants take sufficient residence time in the reactor so that the reaction system approaches the state of chemical equilibrium. This assumption has been adopted to make simulation easier. The coal feeds are initially in standard conditions (25 °C and 1 atm). The final product from the gasification unit is composed of nitrogen (N 2 ), oxygen (O 2 ), hydrogen (H 2 ), carbon monoxide (CO), carbon dioxide (CO 2 ), and methane (CH 4 ), and all these gaseous components behaved as ideal gases. The sulfur present in coal samples does not take part in a chemical equilibrium reaction, and the formation of various sulfur-associated pollutants is neglected in the process. The char produced from gasification consists of solid carbon (C) and ash alone.…”

“…The regression equations are polynomial quadratic-type equations used to express the relationship between independent and response variables. A general polynomial quadratic equation can be written as , y = β 0 + ∑ i = 1 n β i x i + ∑ i = 1 n β ii x i 2 + ∑ i = 1 n − 1 ∑ j = 1 n β italicij x i x j + φ …”

“…The experimental results reported in studies published by Jayah et al 51 and Upadhyay et al 52 were used to validate the present model. The model was also validated using published simulation results reported by Kombe et al 45 The feedstock characterizations used in studies selected for result comparison are given in Table 4. In the study by Jayah et al, 51 rubber wood was gasified in a laboratory-scale downdraft gasifier at 900 °C and 1 atm using air as an oxidant.…”

“…As per Le Chatelier's principle, the equilibrium of an endothermic reaction shifted toward the product direction on increasing the reaction temperature, while exothermic reactions behave in just the opposite manner. 43,45 The concentrations of CO and H 2 in syngas increase with an increase in temperature due to reactions R4, R5, and R10, and the concentrations of CH 4 and CO 2 decrease due to equilibrium shifts of reactions R6 and R9 toward the reactant direction. Less formation of H 2 at higher temperatures is due to the insufficient availability of steam or CH 4 in reactions R5 and R10.…”