Laboratory investigation removal of heat stable salt anions and chloride from industrial lean amine solvent using anion exchange resin in first refinery of SPGC

The formation of heat stable salts (HSS) in natural gas sweetening unit causes many problems such as corrosion, foaming and fouling of the equipment. HSS being resistant to heat cannot be removed from the solvent by simple heating in the regenerator, hence demanding new approaches for HSS removal from aqueous solution of lean amine (methyldiethanolamine) solvent. In this study, commercial anion exchange resins designated as Resin Lewatit monoplus mp 800 was tested to remove major anions such as chloride, Thiosulfates, formate and Acetate from direct raw industrial lean amine solution. Batch and continues ion-exchange adsorption studies. The solvent to resin ratio was seen to administer a prime effect on controlling the adsorption process. It was observed that Acetate has maximum 99.34% removal than Thiosulfate (97.89%) and formate (96.87%) and chloride (96.50%) for fixed solvent to resin ratio of 20. SEM and FTIR analysis on Resin mapped the surface morphology changes and interaction of HSS adsorption process over the resin. The equilibrium batch sorption studies for chloride anion removal was fitted into Langmuir, Freundlich, model isotherms to obtain the best fitted model. It was observed that Langmuir equilibrium isotherm best explained the ion exchange process. The Langmuir model predicted qmax value of 625 mg/g. The breakthrough curves for removal of chloride in column bed with 1.0 cm column diameter and flow rate of 5 ml/min was achieved within 2 h.

کلیدواژه ها:

Sweetening gas ، Heat stable salts ، Chloride ، MDEA ، Ion Exchange resin