煤在H_2/Ar等离子体中直接转化制乙炔的研究

Study on acetylene preparation from coal conversion directly by plasma

以大同煤为原料,通过富氢等离子体条件下的热解实验,考察了供粉速率对煤转化率、乙炔收率和能耗的影响;探讨了热解气相产物中乙炔与一氧化碳和其它小分子烃类的关系.研究结果表明:随着供粉速率的增加,煤的转化率和乙炔的收率呈下降趋势,而甲烷等小分子烃类物质的收率增加,乙炔在产品气中的浓度相应升高,比能耗相应地下降;产品气中一氧化碳的生成和乙炔的生成不存在明显的竞争关系,氧的存在要与乙炔的生成争夺活性碳原子,对乙炔的生成产生不利影响.在所选的实验条件下,当进煤量为5 0g/s时,煤的转化率为38 42%,产品气中乙炔的摩尔分数可达9 3%,乙炔在产品气烃类中选择性大于70%.

To develop an innovative method for directly converting coal into an important chemical material-acetylene, arc plasma technology was applied to the direct conversion of coal. The powdered coal from Datong was injected into a hydrogen-enriched plasma reactor for pyrolysis. The results show that the coal conversion and the acetylene yield and the special energy consumption (SEC) of acetylene are decreased as coal feed rate is increased, but the concentration of acetylene in production gas is increased. The yield of acetylene is not obviously affected by the formation of CO in production gas. Since oxygen can compete with the active atomic carbon, therefore, the high content oxygen in coal is disadvantageous to the formation of acetylene. Under the experimental conditions selected, the coal conversion rate reach 38.42%, the concentration of acetylene in product gas is 9.30% and the selectivity of acetylene in hydrocarbon is above 70% when the coal feed is 5.0 g/s.