煤种对煤与天然气共气化过程的影响

Effect of Coal Type on Coal and Natural Gas Co-gasifying Process

以移动床为反应器,进行煤与天然气共气化热态模拟实验,对无烟煤、瘦煤、肥煤与焦炭进行了对比研究,考察了煤种在不同喷吹参数H2O/CH4/O2时对高温火焰区温度、合成气有效成分H2+CO和H2/CO、以及CH4与水蒸汽转化率的影响.结果表明,相对于焦炭,煤为原料时,高温火焰区温度略高,粗合成气有效成分H2+CO体积含量较高,且H2/CO更接近于热力学平衡值.通过不同煤种的实验,可以直接制备H2/CO在1～2之间可调、有效成分H2+CO体积含量大于92%、残留CH4小于2%的粗合成气,CH4转化率超过90%,水蒸汽转化率高达75%.煤种中高灰分含量有利于煤与天然气共气化过程.

Coal and natural gas co-gasifying process is a new technology to produce synthesis gas based on natural gas steam reforming and coal gasification. A moving bed was used as the reactor in hot simulation experiments. With anthracite, lean and fat coals and coke as the raw materials, the effect of different coal types on the temperature in the flame zone was studied. The effect of coal type on the ingredients of synthesis gas, the methane and steam conversions was investigated in the experiments. With the coals as the raw materials, the results showed that the temperature in the flame zone and the content of active compounds （H2＋CO） were higher than those of coke. In addition, the H2/CO ratio of synthesis gas was close to the value calculated by thermodynamic equilibrium. For the crude synthesis gas produced in this work, the content of active compounds is not less than 92%, the rudimental methane less than 2%, and the H2/CO ratio in the range of 1-2. The steam conversion rate is more than 75%, and the methane conversion rate over 90%. The higher ash content of coal is advantageous to the coal and natural gas co-gasifying process. The experimental results have proved that the coal and natural gas co-gasifying process is a new technology to produce synthesis gas suitable to the resource characteristics in China.