Improvement of Separation Efficiency in Crude Distillation Columns

Abstract

This research was conducted on Nile Blend Crude Oil to improve the separation efficiency in crude distillation columns. El-Obeid atmospheric crude distillation unit efficiency was considered as study case of the research and the column efficiency in the period of (1998-2007) was investigated. Using Under Wood, Fenske, and Gilliland equations, the number of minimum plates at El-Obeid Refinery Company (ORC) crude distillation column was found to be 16 and that the number of theoretical plates was found to be 37, whereas, the number of actual plates at ORC was 46. With calculated overall efficiency of 80%. Aspen plus 12.1 program was used to simulate crude distillation column with specified parameters to improve the separation efficiency at El-Obeid Refinery Company (ORC). API° of Nile blend crude oil was 32.2 and its density at 60°C was 964.2 kg/m3, carbon residue was 4.2, water content was 0.35%, sulfur content was 0.06, etc, as shown in table (4.1). The properties of the products were shown in tables (4.2) through (4.5). The experiments were executed at Khartoum Refinery Company (KRC). Central Lab and El-Obeid Refinery Company (ORC). Khartoum Refinery Company processed 100.000 barrels/day and produces liquefied petroleum gas (LPG) 9.5%, gasoline 35.0%, Jet oil 7.0%, gas oil 32.0% coke, refinery fuel and losses 16.5% on the other hand El Obied refinery Company processed (10.000 – 15.000) barrels/day and produces; Naphtha (6.40%), Kerosene (7.90%), gas oil (22.8%), Furnace (62.82%%) and losses (0.08%). Aspen plus simulation flow sheets for a feed of (10,12 and 14 ton/day) showed an increase in oil products as the amount of feed increased. When the feed of the Nile blend was of 904229.9 light Naphtha, heavy Naphtha, kerosene, and gas oil were changed to 37618.9, 7570.7, 15912.3, and 105464.5 lb/hr respectively. When the feed was raised to 1108897 bbl/day, the light Naphtha, heavy Naphtha, kerosene, gas oil and residue products were of 45789.3, 7569.5, 15706.9, 137323.7lb/hr respectively, On the other hand, when the feed was raised to 129368.0 lb/hr, light Naphtha, heavy Naphtha, Kerosene, and gas oil were 53320.6, 75661, 15674.4 and 149499.3 lb/hr respectively.