Biomass gasification in molten salt for syngas production

Abstract

The dynamic release characteristics and compositions of gas products under different parameters were obtained by using an online gas analyzer from cotton stalk gasification in molten salt (Na2CO3–K2CO3–Li2CO3) with CO2. The parameters studied included CO2 flow rate (50–400 mL/min), CO2 concentration (0–100%), temperature (750–950 °C) and feedstock particle size (0.1–8 mm). The increase of CO2 flow rate, CO2 concentration and temperature all promoted the gasification of cotton stalk for more CO production due to the enhanced Boudouard reaction, greatly improving the gasification efficiency. With the increase of feedstock particle size, the gasification efficiency firstly increased and then decreased owing to the different heating conditions of feedstock particles, and the maximum value of 88% was obtained at 0.8–1 mm. Additionally, CO content almost accounted for more than 80% in gas products, with yield around 850 mL/g. The contents of CH4 and H2 were equivalent, while C2+ content was less than 1%. A maximum gasification efficiency of 125% was obtained under the optimum gasification conditions: 850–900 °C, 50–100% CO2 and 1 mm. And CO2 flow rate should be determined according to the feed rate of cotton stalk feedstock.