Location: Fujian Province, China
Start-up time: Jan., 2001
Background:
Original capacity of gas separation plant was 180 Kt/a where propylene tower had 200 layers of V1 valve trays. Before revamping, performance of this plant was good and separation efficiency of propylene tower was also good within 200 Kt/a. Once capacity was larger than 200 Kt/a, separation efficiency of propylene tower obviously decreased.
Capacity of gas separation plant was expected to be 270 Kt/a due to the constantly rising price of propylene product.
Based on overall calculation for whole plant by SEI, depropanizer and propylene tower should be revamped. Client decided to adopt ADV? high performance tray to revamp these two towers after contrast with other vendors, with following demands: Yield and purity of propylene should be no less than 10545 kg/h and 99.6 mol%, respectively; Purity of propane should be no less than 92 mol%.
Solution:
Original valve trays were replaced by ADV? valve trays one by one. The following technologies were adopted:
(1) Increased DC area and adopted sloped DC;
(2) Adopted bubble promoters to improve bubble status and increase open area;
(3) Adopted “Quick-connect” active tray joint methods to further increase open area;
(4) Adopted unique T-shape beam to support center seal pans;
(5) Optimized feed location of propylene tower.
Result:
Capacity of this plant reached to 270 Kt/a soon after it was started-up in Jan., 2001 and maximum capacity was 288 Kt/a. Propylene content from top product of propylene tower was larger than 99.7%. Propane content was 99.8% in bottom product, which was only 95% before revamping. Both capacity and tray efficiency were improved.
Propylene product was increased by 39 Kt/a based on production in 2004. Payback period of revamping plant was less than 3 months.
Currently, it has the highest tray efficiency of propylene tower in contrast with others for ZEHUA.