Dehydration and de-heavy hydrocarbon technology for production of liquefied natural gas from methane-rich mixed gas

Abstract

The invention relates to a dehydration and de-heavy hydrocarbon technology for production of liquefied natural gas from a methane-rich mixed gas. The technology is characterized in that: after a deacidification treatment, the methane-rich mixed gas falls into two parts, one part enters a drying process, and the other part enters a regeneration process. The methane-rich mixed gas entering the drying process undergoes a drying treatment to remove moisture and heavy hydrocarbons from the gas simultaneously in a drying tower adsorbent composite bed, the moisture is removed till an atmospheric dew point lower than or equal to -76DEG C, and the heavy hydrocarbons above C6 are removed till a content of less than or equal to 217ppm. The methane-rich mixed gas entering the regeneration process serves as a regeneration gas of a drying tower regeneration process, and when the regeneration process is completed, the regeneration gas part returns to the process gas of the system. The invention can achieve a good purification effect, and compared with conventional process routes, the equipment investment and the later stage system energy consumption are reduced, the raw material utilization rate is improved, and the operation indexes of each part become clearer and are easier to control. The invention also relates to equipment used by the technology.

Description

technical field [0001] The invention belongs to the front-end purification treatment technology of low-temperature liquefaction of methane-rich gas, and in particular relates to a dehydration and heavy hydrocarbon removal process and device for producing liquefied natural gas from methane-rich mixed gas. Background technique [0002] Under the pressure of environmental protection and energy costs, the proportion of natural gas as a primary energy source in various fields of society is gradually increasing, and its market demand is also increasing rapidly. The traditional pipeline transportation supply method is still the mainstream, but due to the limitation of raw material conditions and user distribution, a considerable part of resources cannot be transported by pipelines for long distances. It is necessary to choose the liquefaction method to convert methane into liquid and then use flexible transportation methods to send it to to the user terminal. The volume of liquefi...

AI Technical Summary

Problems solved by technology

According to the operation of several sets of LNG plants that have been put into operation in China, the purification part of the front-end mixed gas mostly uses acid gas removal units, dry adsorption units and heavy hydrocarbon removal units to gradually remove impurity components. The disadvantages of this situation The reason is that its equipment investment cost is high, and its system energy consumption is also high under normal working conditions

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