Research On Recovery Process Of Oil Gas In Oil Loading Process

Refining and chemical enterprises in the tank farm and loading process,every year a large number of gasoline,kerosene,styrene,xylene,benzene,C9,MTBE and other substances sent by car or train everywhere.Because of the low boiling point of these components,they are volatile,flammable,explosive and other characteristics.In the process of processing,storage and transportation,the inevitable evaporation and gasification,resulting in the loss of oil.If not recycled,it will directly enter the atmosphere,not only cause serious pollution to the surrounding environment,affecting the health of the operators.Many of these volatile organic compounds are carcinogenic,will cause serious harm to human health,according to the"oil and gas loading system of oil and gas recovery facilities section design specification"(GB 50759-2012)the provisions of article 3.01,gasoline,aviation kerosene,naphtha,solvent oil or similar oil loading system of oil and gas recovery facilities should be set up.In this paper,a condensing oil and gas recovery unit and a low temperature diesel oil absorption method are designed for a large domestic refinery vehicle and train loading platform.A large flow simulation software Aspen Plus is adopted.The condensing oil and gas recovery unit has a design load of 1800 Nm~3/h and a total of three stages.The condensing temperature is 8?,-30?and-80?,respectively.The first and two stage condensation form is simple single-stage refrigeration,the refrigerant is propylene,the third stage is cascade refrigeration cycle,the refrigerant is ethylene,and the overlapped refrigerant temperature is determined to be-29.0?.In addition,in order to increase the COP value of the second stage refrigeration,the third stage low temperature tail gas is used as the cold source of the two stage refrigeration cycle cooler.The compression power consumption of condensing oil gas recovery unit is 278.45kW,and the maximum power consumption of unit volume flow is 0.15kWh.The total recovery of oil and gas recovery device for oil volume was 2176kg/h,oil and gas recovery rate as high as 98%,exhaust after treatment in non methane total hydrocarbon content is 45.3g/m~3,the remaining exhaust gas into the Claus sulfur oxidation furnace direct incineration device.The absorption capacity of the oil and gas recovery unit is 1800 Nm~3/h,the absorbent is diesel,the dosage is 25t/h,and the temperature of the absorber is controlled at 5-15?.The chiller uses a simple single-stage propylene refrigerator.Under the standard conditions,the compressor power of propylene compressor is 138.75kW,and the volume of oil and gas handled by unit volume is 0.077kWh.When the oil and gas are absorbed by low temperature diesel oil,the content of non methane and total hydrocarbon in tail gas is 27.14g/m~3,and the recovery rate of oil and gas is more than 98%.The residual tail gas is passed into the incinerator for incineration treatment.In the oil and gas recovery unit,the design of heat exchanger for oil and gas is two units in series,and the model is BEM450-1.6-70.7-6000/19-4.The design model of the evaporator is BEM500-1.6-113.1-6000/19-1.Diesel absorption tower using MELLAPAK 250Y structured packing tower design size of 1.1 meters,the total filling height is 8.4m,the maximum flooding factor is 0.46.