NG treatment with extraction of up to 95% of С₂+ hydrocarbons

Process Description
Feedstock – natural gas – is separated in separator 1 into the separation residue and gas, which is separated into two streams. The first stream is supplied via a bypass line as a heat transfer medium to the heater of the demethanizer 5 and mixed with the second stream cooled in the heat exchanger 3. The combined stream is separated in separator 2 into the separation residue and the gas, which is cooled in heat exchanger 4. The pressure of cooled gas and the separation residue is reduced in devices 8 and 7, respectively, and supplied into the demethanizer 5.
The demethanized condensate, together with the inlet separation residue reduced in the device 6, is supplied into the fractionation unit 10, from which hydrocarbon fractions are removed. In unit 10, cold generated by a cooling machine 11, which is connected to expanders (devices 6-9), is used to cool the column overhead. The pressure of treated NG from the top of demethanizer 5 is reduced in device 9 and heated in heat exchanger 4. The heated gas is mixed with methane-containing gas from unit 10, heated in heat exchanger 3 and discharged from the unit as a commercial gas.

Process features

• Extraction of maximum amount of heavy hydrocarbons
• Minimization of methanol losses
• Elimination of process discharges to the flare

Technical Specification

• Raw NG pressure - 8.0-12.0 MPa
• Applicable for the line of CGTU with unit capacity up to 10 million nm³/day of commercial gas
• Gas condensate withdrawal up to 100.0 % of the potential
• Capacity С₃-С₄ selection up to 99.5%
• Ethane withdrawal up to 80%
• Possibility to produce C₂-С₄ fraction with SVP corresponding to propane

Patents of the Russian Federation No.
2753753

Development level, industrial application
Developed design concepts
Completed feasibility study