Carbon conversion in an atmospheric-pressure entrained coal gasifier

Entrained gasification tests with a Utah high-volatile bituminous coal were performed at atmospheric pressure to assess the influence of particle size, coal feed rate, steam-coal ratio and oxygen-coal ratio. Independent argon-carbon balance and ash balance methods were used to evaluate carbon conversion, with good agreement observed between the methods. A higher O₂-coal ratio and finer particles increased the carbon conversion. Carbon conversion and hydrogen formation showed little dependence on the amount of steam injected in the secondary stream, indicating minimal steam-coal reaction. When the coal feed rate was varied from 23 to 27 kg h⁻¹, a small increase in carbon conversion was observed with no significant change in the gas composition.