Location: Hainan Province, China

Start-up time: 2014

Background:

MDEA aqueous solution was used to remove H2S from LPG in atmospheric-vacuum unit, the existing LPG amine absorber was 3000mm column ID. It was not stable for the performance of desulfurization that the highest content of H2S in LPG product was 48.33ppm and the lowest was 5.58ppm, based on monthly average. The user hoped to revamp it so that the H2S content could stablized less than 10ppm in a long-term basis.

Solution:

Deflection flow and backmixing between two kinds of liquid had great influence on efficiency of desulfurization in such large scale extraction column. ZEHUA could improve efficiency of desulfurization much through D-FlowTM extraction technology.

(1) Existing column shell was used, just revamping internals based on D-Flow TM extraction technology;

(2) High efficienct random packing was used to break and re-mix the dispersed phase;

(3) Vertical baffles were installed to avoid the deflated flow;

(4) Redistributors were added among three sections in order to improve mass transfer.

Result:

LPG amine absorber had a good performance after revamping, which content of H2S in LPG was able to stabilize at about 5ppm. This reconstruction reached expected requirements.