A systematic approach for design and simulation of monoethylene glycol (MEG) recovery in oil and gas industry

Abstract

Monoethylene glycol (MEG) is a widely used hydrate inhibitor in the oil and gas industry to reduce the risk of hydrate formation in pipelines that could cause a blockage. For flow assurance and hydrate inhibition purposes, large volumes of MEG are required to control the hydrate formation conditions in pipelines. Disposal of rich MEG after separation has considerable costs and poses significant environmental concerns. Therefore, the development of an effective process for MEG recovery has been gaining importance. The current study presents a systematic approach to develop, simulate, and optimize MEG recovery using Aspen Plus and ELEC-NRTL thermodynamic package. Two distinct MEG recovery process (MEG-R-P) designs, namely, the vacuum (design I) and atmospheric (design II) distillation, were tested. Both designs have demonstrated exceptional performance in recovering MEG from salts and water and producing lean MEG at a purity of 90 wt%. Design I operating at vacuum conditions outweighs design II in terms of MEG purity and energy requirements. The addition of MEG-R-P has the advantage of recovering and reusing significant amounts of MEG and removing the burden on the environment.

Design, optimization and economic analysis of a monoethylene glycol recovery process: salt precipitation and vacuum operation

“…The simulation results including the effect of different operational parameters and sensitivity analysis for the proposed two designs and scenarios have been presented in our previous work. 29 The following is a summary of the main findings that will be used in economic evaluation.…”

“…The properties and characteristics of rich MEG used in the present study are presented in our previous work. 29 The total cost of the project was estimated based on capital (CAPEX) and the operating (OPEX) costs. The cost of utilities and equipment was determined using Aspen Plus economic analyzer tool.…”

“…The process retrieved up to 99.5% of MEG wit purity of 90 wt% and reduced the overall project cost by 50% (CAPEX ~8.5 MMUSD and OPEX ~47.33 MMUSD). In our previous work, 29 a simulation‐based MEG‐R‐P was proposed considering various operating conditions, unit configurations. The energy requirements, the impact on the percentage of MEG recovery and purity as well as the influence of salt and its precipitation were evaluated and assessed.…”

Reliability and Performance of Vinyl Lactam-Based Kinetic Hydrate Inhibitor Polymers after Treatment under a Range of Conditions

“…If the THI is injected with KHI and is regenerated on site, the KHI polymer will be subjected to elevated temperatures; this can be up to 160 °C if the THI is MEG. 18,19 It is important that the KHI polymer in the MEG does not cause fouling and is not degraded by this thermal treatment as the whole formulation is to be reinjected. If the KHI polymer is not to be recycled, it may be preferable in some regions if the polymer is destroyed before it is discharged in the produced water into the environment.…”

“…Due to the volumes and costs, methanol and MEG are often regenerated and reused. If the THI is injected with KHI and is regenerated on site, the KHI polymer will be subjected to elevated temperatures; this can be up to 160 °C if the THI is MEG. , It is important that the KHI polymer in the MEG does not cause fouling and is not degraded by this thermal treatment as the whole formulation is to be reinjected.…”