Research on Optimizing Operation of Dehydration System in Natural Gas Cryogenic Processing Plant
A cryogenic unit in Daqing Oilfield adopts molecular sieves for dehydration.During operation,there are mainly problems with hydrocarbon absorption and severe pulverization of molecular sieves in the dehydration system,which have an impact on the light hydrocarbon production and operational stability of the unit.On-site investigation and literature review indicate the reasons causing hydrocarbons adsorption,which are surface adhesion on solids,pulverizing and cracking of molecular sieve,entrainment of heavy hydrocarbon in natural gas,and crystal structure damages by sour gas.The selective adsorption of water by molecular sieves is higher than that of any other molecules,base on this character,the molecular sieve adsorption period is adjusted from 10.9 h to 13.7 h,and field experiments are conducted.The results show that the adsorbed hydrocarbons in one adsorption period decreased from 743 kg to 332 kg,the loss of hydrocarbon absorption by molecular sieves is significantly reduced.The strength test of molecular sieve particles from different parts of the molecular sieve tower,and analysis of operation parameters show that rapid pressure increase-decrease in molecular sieve beds and pollution on molecular sieve are the main reasons causing molecular sieve pulverization.Therefore,the operation process has been optimized to ensure that the pressure increase-decrease rates meet the design requirements,and suggestions for adding composite adsorption beds have been proposed to improve the pulverization of molecular sieves.This provides a guarantee for the efficient and stable operation of the molecular sieve system.
dehydration systemmolecular sievehydrocarbons adsorptionpulverizationstrength test
万方数据
维普
