合成气甲烷化工艺技术研究进展

Research development syngas methanation technology

合成气完全甲烷化技术是煤制天然气特有的技术,按照反应器类型,合成气甲烷化工艺可以分为绝热固定床、等温固定床、流化床和浆态床等工艺,其中绝热固定床甲烷化工艺成熟并广泛应用于煤制天然气项目。本文介绍了多种绝热固定床甲烷化工艺,并比较了5种高温绝热固定床甲烷化工艺的流程、技术特点和应用情况。随着研究工作的不断深入,国内绝热固定床甲烷化技术达到了国际技术同类水平,具备了工业化应用条件,但还需在节能降耗、提高催化剂寿命方面加大研究力度。还概述了等温固定床、流化床和浆态床甲烷化工艺,分析了等温固定床、流化床和浆态床甲烷化工艺存在的问题,并指出了后续研究重点,等温固定床工艺应在反应温度控制和反应器开发方面深入研究,流化床甲烷化工艺研究重点放在开发高强度催化剂和工程化放大方面,浆态床甲烷化工艺需要重点研究解决CO转化率较低和催化剂损耗严重的问题。

Compared with other coal-to-chemicals routes,Coal to SNG is characterized by synthesis gas methanation. In view of reactor type,syngas methanation processes can be classified into adiabatic fixed bed process,isothermal fixed bed process,fluidized bed process and slurry bed process. Adiabatic fixed bed process has been proven in industrial application and has been widely used in Coal to SNG projects. Adiabatic fixed bed processes are introduced and five specific processes are analyzed and compared in terms of process,technology characteristics and application situation. Domestic adiabatic fixed bed technology has reached the same level of foreign processes,ready for commercialization. But further research is required on energy saving,consumption reduction and catalyst life. Furthermore, isothermal fixed bed process,fluidized bed process and slurry bed process are also introduced. Their existing problems and further research points are analyzed. As to isothermal fixed bed process, attention should be paid to reaction temperature control and reactor development. Research on fluidized bed process should be focused on the development of catalyst with high strength and engineering scale-up. About slurry bed process,efforts should be made to increase CO conversion rate and decrease catalyst loss.