Location: Quanzhou, Fujian province, China

Start-up time: 2013

Background:

Four columns, which were absorber, fractionator, dethanizer and stabilizer, were included in 2.6 Mt/a light hydrocarbon recovery unit. The purposes of the reconstruction were to enlarge capacity of this unit and to meet the desired operating flexibility, i.e. 60-110%.

Solution:

(1) All internals of absorber, fractionator and trays #8-#30 in dethanizer could be remained without any modification;

(2) Weir loading for trays #1-#7 of dethanizer was too large to operate normally, so downcomer configurations for that parts were modified in order to increase weir length;

(3) Number of passes for trays #1-#25 in stabilizer were changed to four passes due to large weir loading;

(4) Decks for trays #26-#40 in stabilizer were replaced by new decks with increased open area in order to decrease pressure drop and meet desired operating flexibility.

Result:

Requirements for all products could be met so that customer was satisfied with this revamping.

(1) Content of C5+ was less than 2% (v) and vapor pressure was less than 1380kPa for LPG product from top of stabilizer;

(2) Vapor pressure of naphtha product from bottom of stabilizer was less than 72kPa (in summer) and 88kPa (in winter).