Liquefied Natural Gas Plant Purification Technology

With the rapid development of the world economy, the rapid increase inpopulation, energy consumption is growing, the greenhouse gas and all kinds ofharmful substances emissions surge, the environment for human survival challenge. Inthis situation, clean, high calorific value of natural gas energy sources are becomingmore and more important, the development of natural gas industry has become thebest choice of countries in the world to improve the environment and promotesustainable economic development.To the rational use of natural gas resources, the contradiction betweentransportation and utilization of natural gas must be firstly solved. Actually, naturalgas liquefaction made its long distance transportation become reality. Natural gasmust be purified before being liquefied. Purification is to remove water, acid gas(hydrogen sulphide, carbon dioxide), mechanical impurities, heavy components(carbon3,4and above), which is a very important link in the process of production ofliquefied natural gas.Content of this paper is mainly on the impurities contained in natural gasprocessing and the impurity content being reduced to within the permitted values. Itdescribes the purification process, process flow diagram, the control system.Especially, detailed introduction and analysis are made on the whole process ofpurification. According to the author’s many-years work experience in two liquefiednatural gas factories, some detailed descriptions of MDEA solution of molecular sievedehydration, acid gas removal, impurities removal are made. And the summary ofpractical problems and technical difficulties is also made. The analysis of all thefactors that affect the purification process and the proposed improvement method andscheme of purification technology are useful for increasing natural gas processingcapacity and reducing energy consumption.