Method of oxygen-enriched two-stage underground coal gasification

Two-stage underground coal gasification was studied to improve the caloric value of the syngas and to extend gas production times.A model test using the oxygen-enriched two-stage coal gasification method was carried out.The composition of the gas produced,the time ratio of the two stages,and the role of the temperature field were analysed.The results show that oxygen-enriched two-stage gasification shortens the time of the first stage and prolongs the time of the second stage.Feed oxygen concentrations of 30%, 35%,40%,45%.60%,or 80%gave time ratios（first stage to second stage） of 1：0.12,1：0.21.1：0.51,1：0.64, 1：0.90.and 1：4.0 respectively.Cooling rates of the temperature field after steam injection decreased with time from about 19.1-27.4℃/min to 2.3-6.8℃/min.But this rate increased with increasing oxygen concentrations in the first stage.The caloric value of the syngas improves with increased oxygen concentration in the first stage.Injection of 80%oxygen-enriched air gave gas with the highest caloric value and also gave the longest production time.The caloric value of the gas obtained from the oxygenenriched two-stage gasification method lies in the range from 5.31 MJ/Nm^3 to 10.54 MJ/Nm^3.

二阶段的地下的煤气化被学习改进 syngas 的热量的价值并且扩大煤气的生产时间。用充实氧的二阶段的煤气化方法的模型测试被执行。生产的气体的作文，二个阶段的时间比率，和温度地的角色被分析。充实氧的二阶段的气化弄短的结果表演第一个阶段的时间并且延长第二个阶段的时间。喂 30% ， 35% ， 40% ， 45% ， 60% ，或 80% 的集中分别地给了 1:0.12， 1:0.21， 1:0.51， 1:0.64， 1:0.90，和 1:4.0 的时间比率(第二上演的第一个阶段) 的氧。在蒸气注射以后的温度领域的冷却的率从大约 19.127.4 与时间减少了吗？？