煤制天然气产业发展前景分析

我国天然气供不应求的局面将长期存在,而利用煤炭资源相对丰富的特点发展煤制天然气产业,是缓解我国天然气供求矛盾的一条有效途径。煤制天然气产品的低热值比国家天然气质量标准规定的低热值高17.8%～21%,能量转化效率高。当石油价格为80美元/bbl时,与进口天然气、进口LNG相比,煤制天然气价格具有竞争力。固定床鲁奇炉加压气化技术是煤制天然气较好的选择,而耐硫变换、低温甲醇洗、硫回收、丙烯制冷、压缩干燥等工艺单元不存在技术问题。如果我国企业开发的低温甲烷化技术获得成功,那么煤制天然气项目就可以完全实现国产化,使我国煤制天然气技术居于世界前列。利用低品质的褐煤、采用碎煤固定床鲁奇炉加压气化技术,粗煤气中含有8%～12%的甲烷,气化单元投资仅为气流床气化技术的一半,电耗低,同时可实现焦油、轻油、酚、硫磺、硫酸铵等多联产。但对于排出的"黑水"问题,应采取积极措施尽快予以解决。煤制天然气项目最好在示范装置取得圆满成果之后,特别是环境保护问题解决之后,再进行项目的研究和建设。厂址最好设在坑口或煤炭产地附近,并且要考虑输送问题。

Prospects for Coal Gasification in China

Natural gas shortage will be a long-term problem for China.As China has relatively rich coal resources,gasifying coal is an effective approach to alleviating natural gas shortages.The net heat value of coalderived natural gas is 17.8%-21% higher than the value specified in China＇s national natural gas quality standard,meaning higher energy conversion efficiency.When oil price stands at US$80/bbl,coal-derived natural gas is more competitive compared with imported natural gas and LNG.Fixed-bed Lurgi gasifier pressurized gasification technology is a good option for producing natural gas from coal and there are no technological problems with the technical processes such as sulfur-tolerant shift catalysis,Rectisol,sulfur recovery,propylene refrigeration and compression drying.If domestic enterprises succeed in developing low-temperature methanation technology,a coal gasification project can totally use domestically developed technologies.By that time,China will have been on the forefront of coal gasification worldwide.Using low-quality lignite and conny fixed-bed Lurgi gasifier pressurized gasification technology can produce crude gas with 8%-12% methane.Investment in the gasification unit is only half of that in gas flow bed gasification technology.This production process has relatively low electricity demand and can also produce tar,light oil,hydroxybenzene,sulfur and ammonium sulfate.However,measures should be taken to resolve the problem of black water discharge from these projects.It is best to start the research and construction of a coal gasification project after the demonstration unit association with the project yields satisfactory results,particularly after environmental problems are resolved and it is best to locate a coal gasification facility at the mouth of a coal pit or in the proximity of a coal production area having regard to transmission problems.