Technical paper
Options for Removing Methanol from NGL in an Amine Treater
Methanol is commonly injected into hydrocarbon fluids to inhibit hydrate formation. Bulk methanol removal from a hydrocarbon fluid often occurs through separators as it is processed. However, a small amount of methanol in a processing plant's feed can often result in high concentrations (greater than 1,000 ppm) in the natural gas liquid (NGL) product. This work evaluates several methods for removing enough methanol in the amine sweetening unit to meet NGL specifications. It also discusses strategies for preventing methanol buildup in the NGL by understanding the phase behavior through the entire plant. A complete model of the operating plant was created and compared to operating data to make impactful decisions for operating the plant. This paper shows that methanol concentrations in the NGL product can be reduced in the amine treating system by increasing the condenser temperature, increasing amine solvent circulation rate, decreasing the lean amine loading, decreasing stripper pressure, and purging some or all of the stripper reflux.
Methanol is commonly injected into hydrocarbon fluids to inhibit hydrate formation. Bulk methanol removal from a hydrocarbon fluid often occurs through separators as it is processed. However, a small amount of methanol in a processing plant’s feed can often result in high concentrations (greater than 1,000 ppm) in the natural gas liquid (NGL) product. This work evaluates several methods for removing enough methanol in the amine sweetening unit to meet NGL specifications. It also discusses strategies for preventing methanol buildup in the NGL by understanding the phase behavior through the entire plant. A complete model of the operating plant was created and compared to operating data to make impactful decisions for operating the plant. This paper shows that methanol concentrations in the NGL product can be reduced in the amine treating system by increasing the condenser temperature, increasing amine solvent circulation rate, decreasing the lean amine loading, decreasing stripper pressure, and purging some or all of the stripper reflux.