Characteristics of Low-Temperature Gasification Products from Wheat Straw in a Fluidized Bed Based on Cement Production Process

Abstract

This study aimed to improve the safety and economy of cement production and to investigate the gasification performance and tar properties of wheat straw in a small electrically heated bubbling fluidized bed by varying three factors, namely, gasification reaction conditions, fuel quality and type, and the natural environment, so as to promote the application of the low-temperature gasification of biomass in the cement industry. The gasification experiment was carried out at temperatures of 550–700 °C, air equivalence ratios of 0.1–0.2, moisture contents of 5.25–24%, blended rubber ratios of 0–100%, and furnace vacuums of 0–0.03 within the parameter ranges, and the component analyses of the produced gases and tars were carried out by gas chromatography (GC) and gas chromatography–mass spectrometry (GC-MS). The experimental findings revealed that the optimal operating conditions for gasification were attained at a temperature of 650 °C, an equivalence ratio of 0.15, a moisture content of 5.25%, a rubber blending ratio of 0, and a vacuum degree of 0. Under these conditions, the concentrations of combustible components (H2, CH4, and CO) in the produced gas were 4.01%, 4.60%, and 21.05%, respectively. The carbon conversion rate was 62.40%, with the cold gas efficiency of 39.37%. The lower heating value of the produced gas was 5.915 MJ/Nm3, accompanied by a tar yield of 118.15 g/Nm3 and lower heating value of 3.385 MJ/Nm3.