Oil and gas recovery in oil storage tanks, with a modular condensing membrane separation unit

Oil and gas recovery in oil storage tanks, with a modular condensing membrane separation unit

In the process of oil loading and unloading and daily storage, the tank breather valve and loading crane pipe will discharge a large amount of oil and gas. These oil and gas contain benzene series, alkanes and other VOCs, direct emissions not only cause oil loss, but also face strict environmental supervision. Skid-mounted condensing membrane separation unit is one of the mainstream equipment for oil and gas recovery in oil storage depots at present, which adopts the combined process of condensing and membrane separation to achieve standard discharge and at the same time recover oil products to create economic benefits.

The working process of the unit is divided into four links. The oil and gas first enters the compression unit and is sent to the condensation system after being pressurized by the compressor. The condensing unit adopts three-stage step cooling, and the temperature drops to minus 20 to minus 30 degrees Celsius step by step. Most of the hydrocarbon components above C3 are liquefied into gasoline at this stage and flow into the recovery storage tank from the bottom of the equipment. The uncondensed tail gas enters the membrane separation unit and is used.gas separation membraneThe selective permeability difference between oil and gas molecules and air molecules, hydrocarbon organic matter is trapped and enriched, recycled back to the condensation inlet for further treatment, and clean air meets the discharge standard.

The advantage of the skid-mounted design is a high degree of integration. All components, including the compressor, condenser, membrane module, vacuum pump and control system, are installed on a steel base and are assembled and tested before leaving the factory. The site only needs to connect the power supply, connect the oil and gas pipeline and the oil return pipeline, and it can be put into use. The installation period is short and the area is small.

In terms of technical indicators, the overall oil and gas recovery rate of the combined process of condensation and membrane separation can reach more than 95%, and the concentration of non-methane total hydrocarbons in the exhaust gas can be controlled below 25 grams per cubic meter, meeting national and local emission standards. The service life of the membrane module is three to five years. The system adopts PLC automatic control, and automatically starts and stops when the pressure reaches the set value, realizing unattended operation.

In terms of economy, taking an oil storage depot with an annual loading of 100,000 tons of gasoline as an example, after adopting a skid-mounted condensing membrane separation unit, more than 100,000 liters of gasoline can be recovered each year, and the recovery value is considerable. The operation of the equipment only consumes electricity, and two to three liters of gasoline can be recovered per kilowatt-hour, and the operating cost is much lower than other processes.

LuoyangWohong PetrochemicalEquipment Co., Ltd. can provide customized solutions for skid-mounted condensing membrane separation units in oil storage depots. The air volume of the unit covers 100 to 1,000 cubic meters per hour, and the explosion-proof design is suitable for explosion-proof places in oil depots. The company is located at W2-1, Dongda Science and Technology Industrial Park, Luoxin Industrial Cluster Zone, Xin’an County, Luoyang City. Website: www.wohongshihua.com.