Light hydrocarbon recovery unit revamp
Location: Quanzhou, Fujian province, China
Start-up time: 2013
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%.
(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.
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).