Ethylene Recovery Technology (LECT)

1. High ethylene recovery, low energy consumption and simple operation.
2. The gasoline fractionator uses circulating pan oil to remove heat and to make a better temperature distribution in the tower. Pan oil is meanwhile used as   heat source for reboilers of HP/LP depropanizers.
3. PFO stripper is used to control the viscosity of the quench oil, resulting in the increase of bottom temperature of gasoline fractionator.
4. The 5-stages cracked gas compressor with low compression ratio can reduce the fouling caused by cracked gas inside the compressor.
5. The HP/LP-depropanizer system decreases fouling in the reboilers. The C3’s overhead of LP depropanizer are sent back to HP depropanizer. All acetylene and large amount of MAPD are removed in C2 hydrogenation system so that the load of C3 hydrogenation system is reduced.
6. The catalysts for C2/C3 hydrogenation are independently developed by SINOPEC. Main advantages of these catalysts include low investment, and high selectivity. No hydrogen is needed either from the cold recovery system or OSBL during the commissioning stage.
7. C3 washing tower, C2 washing tower, cold box, pre-demethanizer and demethanizer are involved in the cold area so that the streams will be more reasonably distributed. By using this new process, cold duty will be reduced whereas the ethylene recovery rate will be increased.
8. Proprietary Condensating-Fractionate Tower (CFT) is used. It has both heat and mass transfer function, and can separate the materials as well as recycle cold duty.
9. Ethylene fractionator and ethylene refrigerant compressor consist of an open heat-pump system. The ethylene fractionator operates at low pressure so that reflux ratio is also low. The heat-pump system reduces the total power of the refrigerant compressor. Equipment cost is reduced by integrating ethylene fractionator heat-pump compressor and ethylene refrigerant compressor into one compressor.