低阶煤熔融体系电化学转化过程

Electrochemical conversion process of low-rank coal in the molten system

为解决低阶煤转化的高耗能、高污染与分级转化调控难问题,提出一种基于电化学过程的低阶煤转化方法,以镍作为电化学反应阴极与阳极,在熔融体系中,采用热—电化学协同反应过程电解低阶煤进行提质转化。结果表明:低阶煤在熔融体系中能够进行电化学氧化还原反应,随温度的升高,能够有效降低氧化还原电位;低阶煤的电化学转化随反应时间的改变而呈现阶段性变化;电压/电流、温度是低阶煤转化的关键影响因素,通过调控电压/电流与反应度匹配,能够获得理想的低阶煤转化率;在反应温度为360℃、电压为2.0 V、反应时间为4 h条件下,低阶煤电化学转化率可以达到87.3%,其中液体转化率为48.8%,气体转化率为38.5%。

To solve the problems of high energy consumption,high pollution,and difficult regulation of graded conversion in low-rank coal conversion process,a low-rank coal conversion process based on electrochemical process was proposed.Nickel was used as the electrochemical reaction cathode and anode.In the melting system,the thermal-electric cooperative reaction process was used to electrolyze low-rank coal for upgrading and transformation.The results show that the electrochemical redox reaction of low-rank coal can be carried out in the molten system,and the redox potential can be effectively reduced with the increase of temperature.The constant voltage and current tests show that the electrochemical transformation of low-rank coal in the molten system presents a phased process with the change of reaction time.Voltage,current and temperature are the key factors affecting low-rank coal conversion.By adjusting voltage or current to match the reaction temperature,an ideal low-rank coal conversion rate can be obtained.Under the conditions of 360℃reaction temperature,2.0 V voltage and 4 h reaction time,the electrochemical conversion rate of low-rank coal in the molten system can reach 87.3%,including 48.8%for liquid and 38.5%for gas.