Energy Saving Transformation Of Dehydration Process In Natural Gas Liquefaction Plant

In order to cope with the impact of foreign LNG market and the competition of domestic market,and to respond to the call of national energy saving and consumption reduction,and to reduce production costs,we have made a careful comparative study on the purification process of LNG plant.It is found that there is a large amount of waste of heat energy in the dehydration process of natural gas,increasing the hot stove and cooling tower.The load increases the production cost of the factory.By comparing the dehydration technology of liquefaction plants at home and abroad,this paper lists the advanced technology developed in the past year,sums up the dehydration scheme suitable for medium and small LNG plants,establishes the dehydration process,simulates the dehydration process with HYSYS software,recycles the heat of regenerated gas in the process of dehydration and regeneration,and calculates the production.Economic benefits.Taking a natural gas liquefaction plant with a daily capacity of 300,000 square meters in Xinzhou,Shanxi Province as an example,the dehydration process of natural gas is reformed.The idea is to add a gas heat exchanger between the pre adsorption tower and the reheater.In the process of regeneration by molecular sieve heating,the regenerated high temperature natural gas enters the gas heat exchanger first and exchanges heat with the regenerated gas coming from the pre-adsorption tower to the regenerated gas heater.The heat balance between the two can not only increase the regenerated gas temperature of the regenerated gas heater,but also decrease it.The regeneration temperature of the de-regenerated gas cooler is lowered,thus reducing the load of the regenerated gas heater and the regenerated gas cooler.Make the process flow chart after the transformation,use HYSYS software to simulate the process before and after the transformation,and compare the change of heat consumption.Then design and calculate the heat exchanger and other equipment.The results show that after retrofit,the energy consumption is obviously reduced,and the waste heat recovery is realized,resulting in economic benefits.