Environmentally friendly technology of discharge and degassing of LPG railway tanks

Process Description
After reaching normative pressure in tank cars 2, nitrogen is supplied from unit 3, and a mixture of LPG and nitrogen vapors is supplied to unit 5 using unit 4. In unit 5, mixture of LPG and nitrogen is cooled, condensed and separated to produce LPG, which is supplied to container 1, and a depleted mixture of LPG and nitrogen vapors, which is mixed with nitrogen supplied from unit 3.

Process features

• Prevention of atmospheric contamination by hydrocarbons
• Options: a) with use of nitrogen as purge gas b) without use of nitrogen, nitrogen-carbon dioxide mixture is used as purge gas, generated in oxidation and drying unit during oxidation of vents from railway tank cars

Technical Specification

• LPG recovery at least 96% (with nitrogen purging), at least 92% (with nitrogen-free technology)
• Residual content in the tank car after degassing: hydrocarbons – 0.1–0.2 LEL; oxygen – less than 1%, water – none
• Degassing time of 5 railway tank cars: 2.5–4 hours

Patents of the Russian Federation No.
2649496, 2650246, 2654777, 2654779

Development level, industrial application

• Developed design concepts