CO2 And H2S Co-Removal From Natural Gas Using Membrane Contactor Technology

Abstract

Acid gas removal mainly CO2 and H2S from natural gas is an essential treatment process in the oil and gas industry to increase the heating value of sales gas, prevent corrosion of pipeline and process equipment’s and avoid crystallization during the liquefaction process (Ahmad et al., 2010). Among the popular acid gas removal technologies, the amine-based acid gas absorption process that relies on chemical absorption of acid gas into aqueous amine solution followed by thermal regeneration is one of the technologies that is widely used in the oil and gas industry for acid gas treatment (Brau et al., 2017; Yu et al., 2012; Tay et al., 2017). For amine-based acid gas removal technology, contactors play an important role to ensure efficient and economical separation processes. Membrane contactor technology is one of the promising alternatives to existing conventional contactors that provides a large surface area per unit volume, independent gas and liquid flow rate and ease of scale-up for the acid gas absorption process. In this study, the feasibility of using membrane contactor technology for CO2 and H2S co-removal at high pressure was investigated. The effect of operating parameters such as gas flow rate, liquid flow rate and amine concentration on CO2 and H2S removal performance using activated MDEA as liquid absorbent was conducted using the design of experiment approach. Results from experimental runs have shown that the H2S target outlet which is ≤50 ppm was achieved at all operating conditions but not for CO2 outlet. The target CO2 outlet which is 6.5 mol% was only achieved at experimental runs where the condition of gas flowrate is the lowest, liquid flowrate is the highest and amine concentration is the lowest. The results achieved have proven that there is a high potential to use membrane contactor technology for co-removal of CO2 and H2S from natural gas.

Numerical Modeling and Economic Analysis of Ultrasonic-Assisted CO2 Absorption Process for Offshore Application

“…Due to this, piperazine (PZ), a cyclic diamine, is usually used with MDEA as the activator for CO 2 removal because of its rapid formation to form carbamate and bicarbamate with CO 2 [5,12]. The blended MDEA and PZ solvent (known as activated MDEA, or aMDEA) is usually employed to remove both CO 2 and hydrogen sulfide (H 2 S) from natural gas during the sweetening process [9,13,14]. The aMDEA solvent was developed in the 1970s and patented by BASF for the CO 2 absorption process, with a removal efficiency higher than the traditional MEA and potassium carbonate solvents.…”