Light hydrocarbon recovery unit is a special device for recovering light hydrocarbon. The mature and reliable process technology is adopted to treat the gas and initial top gasoline of four sets of atmospheric and vacuum distillation units. The recovery rate of C3 and C4 light hydrocarbon is 10.69%.
Function of light hydrocarbon recovery unit: the function of light hydrocarbon recovery unit is to recover light hydrocarbon, which is also known as natural gas condensate (NGL), covering C2 ~ C6 + and containing condensate components (C3 ~ C5). Light hydrocarbon recovery is a process in which heavier components in natural gas than methane or ethane are recovered in liquid form.
On the one hand, the purpose is to control the hydrocarbon dew point of natural gas to achieve the quality index of commercial gas and avoid gas-liquid two-phase flow; on the other hand, the recovered liquid hydrocarbon has great economic value, which can be directly used as fuel or further separated into ethane, propane, butane or propane butane mixture (liquefied gas), light oil, etc., and can also be used as chemical raw materials.
Technical performance and characteristics of light hydrocarbon recovery unit:
1. Dehydration and separation system: this system is a natural gas through the separation device, through low-speed, rotary separation, metal filter screen and other processes to fully separate water, heavy oil, sediment, etc., greatly reducing the load of the subsequent process system and cumbersome maintenance. The remarkable feature of the system is the addition of rotating separation and metal wire mesh filtering devices, the separation effect is significantly increased.
2. Compression and purification system: the compression system adopts oil-free compressor and evaporative condenser for cooling, which has the characteristics of low energy consumption and convenient maintenance.
3. Drying system: this system uses 4A molecular sieve, gas heating and reduction, automatic exchange and other characteristics, good energy saving effect, the labor intensity of operators has been reduced.
4. Refrigeration system: the device adopts ammonia refrigeration cycle system, the compressor is piston refrigeration compressor, the motor power is automatic frequency conversion, the auxiliary machine adopts evaporative condenser and aluminum plate evaporator, which has the functions of energy saving, water saving, good heat exchange effect and so on, and occupies a small area. The valve is not sealed by welding.
5. Cooling and separation system: the system adopts four-stage heat exchange, which makes full use of energy. The preheater, ammonia evaporator and gas-gas heat exchanger are all made of aluminum sheet tube, with good heat exchange effect. The precooling can completely remove water and avoid ice blockage. The separator adopts liquid level automatic discharge to reduce the labor intensity.
6. Automatic control system: the device adopts DSC automatic control system to realize decentralized control, centralized display and operation, with display, monitoring, alarm and other functions, instead of manual operation, improving production efficiency.