Influence of mid-point temperature of heavy hydrocarbons separator to the liquefaction process for small LNG plant

Abstract

In liquefied natural gas (LNG) process production, one of the important units is heavy hydrocarbon removal unit to prevent freezing during liquefaction. For small scale of LNG plant, this unit is usually integrated with main heat exchanger. Feed is obtained from main heat exchanger then flows to separator to separate liquid from gas. The separator operating condition is called as Midpoint condition. Selecting Midpoint conditions have impact to light hydrocarbon losses, Specific Brake Horse Power (SBHP) process, and heating value of LNG. Hence understanding of selecting this condition and its effect to light hydrocarbon losses, SBHP process, and HHV of LNG will help to design more efficient LNG plant. According to study, the lower of Mid-Point temperature will result in lower SBHP, lower of light hydrocarbon losses, and increase LNG of HHV value. Meanwhile, the higher Mid-Point pressure will result in lower SBHP, higher light hydrocarbon losses, and lower LNG of HHV value. The change of Mid-Point pressures have more impact to light hydrocarbon losses than SBHP process.