Gasification of kitchen wastes in an updraft fluidized bed gasifier and simulation of the process with Aspen Plus

Abstract

Kitchen wastes can be converted into a gaseous source for the generation of energy rather than being dumped around recklessly which results into environment pollution. Less amount of carbon in the wastes (56%) can lead to a decrease in the amount of carbonaceous gases produced in gasification than that from other energy sources like coal, wood and bagasse. The gasification of kitchen wastes was carried out cost-effectively in an in-house designed laboratory scale updraft fluidized bed gasifier along with a cyclone separator and a cooler. Variation of temperature in a range of (400–800) °C, air flow rate (2.8 L/h and 7 L/h), moisture content (30% wt. of feed) and feed weight (50–150) g were investigated on the gasification of kitchen wastes to optimize the process in respect to the production of CO, CO2, CH4, tar and char. The higher the temperature utilized in the process, the conversion into gases was obtained the higher up to 800 °C. Air flow rate did not affect the process much other than fluidizing the feed in the gasifier. Feed weight had shown a substantial effect in the process. A simulated model for the gasification process involving the different parameters applied in the gasifier was developed with the help of Aspen Plus V8.8 software in order to compare the experimentally obtained data with the theoretically simulated results. The kitchen waste can be directly converted to valuable energy sources materials at a low temperature conversion process in a fluidized bed gasifier using non-treated air as a fluidizing agent, which helps to distribute the heat throughout the reactor uniformly and facilitate the gasification. Comparing the experimental data with the simulated one, it is observed that application of high temperature will not be suitable for kitchen waste gasification.