This document is an expanded abstract.
Summary
A novel electromagnetic separator (EMS) is designed and developed for removal of heat stable salts (HSS) from industrial lean amine solution used in gas sweetening units. The designed setup is concentric with an outer tubular pipe serving as anode and an inner rod serving as a cathode when connected to an external power supply. The direction of electric field will be radial and perpendicular to the flow path along the channel to enhance the separation of ions at the outlet. The setup has been tested under normal operating conditions. The concentration of HSS was analyzed for each experiment at a fixed voltage and flow rate at different operating time. Various operational parameters, like voltage, flow rate and magnetic field strength are studied to examine the efficiency of the designed system. It was found that the separation efficiency increased on increasing the operational voltage up to 3V, and by decreasing the flow rate and introducing magnetic field on to the system. The developed setup demonstrated potential in removal of HSS from lean amine solutions.
Introduction
Alkanolamine based solvents are widely employed in the gas processing industry to remove acid gas impurities like CO2 and H2S. Most commonly used alkonanolamines for this process are monoethanol amine (MEA), Diethanolamine (DEA) and N-methyl diethanolamine (MDEA). Amine degradation and contamination occurs mainly by the oxidation and thermal degradation of amine itself or by some trace impurities produced during refining or by reaction with oxygen and the acidic gases adsorbed resulting in the production of heat stable salts (HSS) like acetates, formates, sulphates and nitrates. These salts slowly accumulate in the amine solvent therby having detrimental effect on the efficiency of absorptive removal and causing corrosion as well as create operational problems like foaming and amine loss. Hence the periodic removal of HSS is important to maintain overall efficient performance of the amine solvent system.
