Biomass Downdraft Gasifier Controller Using Intelligent Techniques

Synthetic gas generated from the gasification of biomass feedstocks is one of the clean and sustainable energy sources. In this work, a fixed-bed downdraft gasifier was used to perform the gasification on a lab-scale of rice husk, sawdust, and coconut shell. The aim of this work is to find and compare the synthetic gas generation characteristics and prospects of sawdust and coconut shell with rice husk. A temperature range of 650–900 °C was used to conduct gasification of these three biomass feedstocks. The feed rate of rice husk, sawdust, and coconut shell was 3–5 kg/h, while the airflow rate was 2–3 m3/h. Experimental results show that the highest generated quantity of methane (vol.%) in synthetic gas was achieved by using coconut shell than sawdust and rice husk. It also shows that hydrogen production was higher in the gasification of coconut shell than sawdust and rice husk. In addition, emission generations in coconut shell gasification are lower than rice husk although emissions of rice husk gasification are even lower than fossil fuel. Rice husk, sawdust, and coconut shell are cost-effective biomass sources in Bangladesh. Therefore, the outcomes of this paper can be used to provide clean and economic energy sources for the near future.

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Downdraft gasifier design calculation for biomass gasification using exhaust gas as a gasification agent

Materials Today Proceedings ◽

10.1016/j.matpr.2021.03.520 ◽

2021 ◽

Author(s):

Sherif Elshokary ◽

Sherif Farag ◽

OSayed Sayed Mohamed Abu-Elyazeed ◽

Bitu Hurisso ◽

Mostafa Ismai

Keyword(s):

Biomass Gasification ◽

Design Calculation ◽

Exhaust Gas ◽

Downdraft Gasifier

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Simulation of a Downdraft Gasifier for Production of Syngas from Different Biomass Feedstocks

ChemEngineering ◽

10.3390/chemengineering5020020 ◽

2021 ◽

Vol 5 (2) ◽

pp. 20

Author(s):

Mateus Paiva ◽

Admilson Vieira ◽

Helder T. Gomes ◽

Paulo Brito

Keyword(s):

Modeling And Simulation ◽

Pilot Scale ◽

Operating Conditions ◽

Fuel Gas ◽

Heating Value ◽

Downdraft Gasifier ◽

Process Operation ◽

Independent Parameters ◽

Gasification Temperature ◽

Main Operating

In the evaluation of gasification processes, estimating the composition of the fuel gas for different conditions is fundamental to identify the best operating conditions. In this way, modeling and simulation of gasification provide an analysis of the process performance, allowing for resource and time savings in pilot-scale process operation, as it predicts the behavior and analyzes the effects of different variables on the process. Thus, the focus of this work was the modeling and simulation of biomass gasification processes using the UniSim Design chemical process software, in order to satisfactorily reproduce the operation behavior of a downdraft gasifier. The study was performed for two residual biomasses (forest and agricultural) in order to predict the produced syngas composition. The reactors simulated gasification by minimizing the free energy of Gibbs. The main operating parameters considered were the equivalence ratio (ER), steam to biomass ratio (SBR), and gasification temperature (independent variables). In the simulations, a sensitivity analysis was carried out, where the effects of these parameters on the composition of syngas, flow of syngas, and heating value (dependent variables) were studied, in order to maximize these three variables in the process with the choice of the best parameters of operation. The model is able to predict the performance of the gasifier and it is qualified to analyze the behavior of the independent parameters in the gasification results. With a temperature between 850 and 950 °C, SBR up to 0.2, and ER between 0.3 and 0.5, the best operating conditions are obtained for maximizing the composition of the syngas in CO and H2.

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