煤制天然气联产化学品工艺路径探讨与分析

Investigation and analysis of coal-based co-production process of synthetic natural gas and chemicals

煤制天然气示范项目存在产品生产模式单一、煤炭转化增值偏低等问题,在天然气面临价格下调的背景下,单一的产品结构已经成为制约煤制天然气项目健康发展的瓶颈问题。本文从煤基多联产的角度出发,探讨和分析煤制天然气工厂多联产化学品生产路径,旨在实现终端产品多样化和高值化,提高企业经济效益。本文通过对国内主要联产化学品需求和关键单元技术分析的基础上,结合现有煤制天然气工艺技术特点,提出了煤制天然气厂联产甲醇和联产甲醇、乙二醇两种联产方案,并对两种方案进行概念设计以及物料衡算。通过对两种联产方案进行技术经济分析发现,联产甲醇、乙二醇方案在内部收益率和投资回收期关键经济指标方面具有明显的优势。因此,在煤制天然气项目的基础上建立联产甲醇、乙二醇装置是解决现有煤制天然气项目瓶颈问题最为适合的路径。

Coal to synthetic natural gas (SNG) demonstration projects exist serious problems of monotonous production model and low value increase of coal.Under the circumstance of the decline in natural gas price,the single product structure has become to be the bottle-neck of healthy development of coal-to-SNG industry.In this paper,the coal-based co-production process of synthetic natural gas and chemicals is discussed and analyzed systematically.The coal-based co-production system is aiming to diversify and improve the value of terminal products by integration a variety of coal conversion technology.Based on the investigation of the domestic demand for the co-production chemicals and the key unit process,two schemes that co-production methanol scheme and co-production methanol and ethylene glycol scheme are proposed.The conceptual processes are designed and mass balance are calculated.On this basis,techno-economic performances are systematically analyzed.The results show that the co-production methanol and ethylene glycol scheme has obvious advantages in key techno- economic indicators,such as in internal rate of return and economic indicators of payback period.In summary,the co-production methanol and ethylene glycol scheme is the best program for coal-to-SNG co-production chemicals process to solve the bottleneck problem of the existing coal-to-SNG projects.