Evaluation of Chemically Modified Mono-Ethylene Glycol as a Potential Solvent for Enhanced Natural Gas Dehydration Process

Natural gas dehydration using glycol absorption process is one of the gaseous phase water removal technique which is efficient and cost effective. Glycols used for the absorption ranging from mono-ethylene glycol, di-ethylene glycol , tri-ethylene glycol to tetra-ethylene glycol in which tri-ethylene glycol is widely used due to its high dehydration performance. However, many industries in Malaysia that used this approach rarely able to combine high performance, economic energy consumption and low environmental emission. The main problem with the usage of tri-ethylene glycol is BTEX emission, which BTEX are classified as carcinogenic chemicals and are considered as air toxin. Besides, the non-availability of tri-ethylene glycol locally in Malaysia increases the cost of dehydration. Therefore, the locally produced mono-ethylene glycol by OPTIMAL Glycols (M) Sdn. Bhd. with a production of 365000 MTPA make it an attractive candidate. In this study, chemically modified mono-ethylene glycol is used as a new solvent to replace tri-ethylene glycol. The objectives are to simulate different natural gas dehydration processes using mono-ethylene glycol as new solvent, to validate and optimize the simulation besides to investigate enhancement of the dehydration process through chemical modification of mono-ethylene glycol. The scope of study includes comparing the chemically modified mono-ethylene glycol with tri-ethylene glycol in terms of performances; for example, the outlet natural gas water content and BETX emission. The data and results are obtained by process modeling using Aspen HYSYS 8.4 (latest) simulation software.