Retrofitting of an Existing Condensate Recovery Plant to Maximize Natural Gas Liquids Production

Abstract

Nowadays, gas processing for NGLs (Natural Gas Liquids) and LPG (Liquefied Petroleum Gas) recovery has gained a great interest due to the increase of the market demand as well as the higher prices of these products. Based on sales gas calorific value from ABU-SANNAN Condensate Recovery Plant (General Petroleum Company-Egypt) and by close monitoring of NGLs content in feed and sales gas, it is clear that there is a valuable amount of NGLs leave with sales gas without recovery. NGLs have significantly greater value as separated products than as part of the gas stream, so General Petroleum Company could seek ways and means to maximize NGLs recovery. The current research work proposes a possible modification of ABU-SANNAN Condensate Recovery Plant to produce liquefied petroleum gas (LPG) from natural gas liquids (NGLs), instead of producing lighter hydrocarbon gases during the stabilization process, in addition to the current condensate and sales gas products. The new LPG recovery unit will comprises of: Molecular Sieve based-dehydration unit, Turbo-Expander unit, Cold Box heat exchanger, DE-ETHANIZER system, DE-ETHANIZER Overhead compressor, DE-BUTANIZER system, and two LPG storage bullets. New process equipment selection, sizing and rating will be performed by using Aspen HYSYS simulation program V8.8. The results show that the retrofitted plant can produce 87 Tons/Day of LPG. The produced LPG can participate to solve the LPG shortage problem in Egypt. The economic evaluation for the Retrofitted Plant is conducted by using Aspen Capital Cost Estimator V8.8, to ensure rapid return of investment and good profitability over the expected lifetime. It is remarkable that the Retrofitted plant has a great value from the economic point of view as the total capital investment will be paid back within two years, so the Retrofitted plant will achieve a high and rapid return on investment (ROI). The efforts done in this work are helpful and can be applied for plants in operation as well as the plants under design for increasing their profits.

Simulation of Liquefied Petroleum Gas Recovery from Off Gases in a Fuel Oil Refinery

“…The optimum vent rate is 0.53 MMSCFD. Almost 98% of ethane is recovered at this vent rate, which means only 2 % of LPG losses occur, which is a negligible loss [11,21]. The bottom product of the de-propanizer solvent is to be recycled, so it mustn't contain light fractions in it.…”

“…Thusly membrane separation is an earlier choice in the remote zones where utilities like cooling water and steam are not effectively accessible. Convincingly, expander separation is efficient for little to the medium progression of off-gases and higher stream rates; absorption is the favored procedure [21].…”