Condensing Recovery Of Natural Gas Light Hydrocarbon

This subject comes from the adaptation project of the Kelameili Gas Field.Kelameili treatment station is currently using the"J-T valve throttling+alcohol antifreeze"treatment process,it is difficult to recover hydrocarbon components such as ethane,propane and stable light hydrocarbon because of the limitation of refrigeration temperature.The processing station needs to build a new light hydrocarbon recovery unit with a treatment capacity of 2.5×10~6 Nm~3/d to recover light hydrocarbons from natural gas.This article analyzes and compares the advantages and disadvantages of natural gas dehydration,desolidification,and condensate stabilization processes,and comprehensively considers the benefits and requirements of the light hydrocarbon recovery process for comparative analysis.The pretreatment method of molecular sieve dehydration,non-renewable decontamination of solid impurities,adsorption and desolidification was determined.Using hysys to simulate cooling methods such as mixed refrigerant refrigeration,expander refrigeration,expander refrigeration,and propane precooling,analyze the advantages and disadvantages of the three refrigeration methods and analyze the mixed refrigerant ratio and adaptability of mixed refrigerant refrigeration light hydrocarbon recovery process.The optimum mixing ratio for determining the mixed refrigerant refrigerant is methane:ethylene:propane:n-butane:nitrogen=0.4966:0.2856:0.036:0.1153.The conclusion is that the best cooling method is expander refrigeration.Hysys was used to simulate and optimize the DHX process and RSV process for light hydrocarbon recovery.By comparing the optimized process parameters and the comprehensive benefits of the processing station,the appropriate natural gas light hydrocarbon recovery process,RSV process,is selected.The conclusion is that the expander refrigeration temperature is-108.8°C,the expansion ratio is 3.5,the expander outlet pressure is 2000 kPa,the dry gas reflux ratio is 0.1,and the cryogenic separator separation temperature is-46.0°C.The ethane yield of the process was 98.05%,the propane yield was 99.99%,and the ethane content in the ethane product was 98.34%by mole.Finally,the entire system of waste heat recovery research and the main equipment selection.