Development of Adsorption-Based Process for Heavy Hydrocarbon Removal from Lean Natural Gas

摘要

To prevent freezing of the heavies in LNG (Liquefied Natural Gas) production, one of the requirements in the pretreatment step is the removal of heavy hydrocarbons (C6+). Traditionally, this is done using a distillation approach by a scrub column. If the gas is rich, NGL (Natural Gas Liquid) can also be produced from the bottom of the scrub column. However, when the gas becomes lean in C2 or C3+, the scrub column can easily dry out due to insufficient liquid reflux. The possible solution for providing the needed cold liquid is either from the downstream cold box or/and feed gas expansion. Both options are very energy inefficient for the scrub column operation when it comes to the lean gas.