Modeling of Nanofiltration Process Using DSPM-DE Model for Purification of Amine Solution.

Asma Ghorbani,Tavan Kikhavani,Enrico Drioli,Mirko Frappa,Francesca Macedonio,Behrouz Bayati

doi:10.3390/membranes11040230

Asma Ghorbani, Tavan Kikhavani + Show 4 more

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https://doi.org/10.3390/membranes11040230

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Abstract

The formation of heat stable salts (HSS) during the natural gas sweetening process by amine solvent causes many problems such as corrosion, foaming, capacity reduction, and amine loss. A modeling study was carried out for the removal of HSS ions from amine solution using nanofiltration (NF) membrane process that ensures the reuse of amine solution for gas sweetening. This model studies the physics of the nanofiltration process by adjusting and investigating pore radius, the effects of membrane charge, and other membrane characteristics. In this paper, the performance of the ternary ions was investigated during the removal process from methyl di-ethanol amine solution by the nanofiltration membrane process. Correlation between feed concentration and permeate concentration, using experimental results with mathematical correlation as Ci,p = f (Ci,f) was used in modeling. The results showed that the calculated data from the model provided a good agreement with experimental results (R2 = 0.90–0.75). Also, the effect of operating conditions (including feed pressure and feed flow rate on ions rejection and recovery ratio across the flat-sheet membrane) was studied. The results showed that the recovery and rejection ratios of the NF membrane depend on the driving pressure across the membrane. While the driving pressure is affected by the feed flow conditions and feed pressure.

Highlights

Natural gas is a nonrenewable energy source that usually contains undesirable species such as hydrogen sulfide (H2S), and carbon dioxide (CO2), which as well as being harmful to human health cause problems such as corrosion, plugging, freezing, erosion, and environmental hazards [1,2,3,4,5,6]
methyl diethanolamine (MDEA) solution was high according to the Van’t Hoff equation (π = CRT, where π is the osmotic pressure, R is constant of proportionality called general solution constant or gas constant, C is the concentration of the solution and T is the temperature [67]), and the rejection of MDEA by NF-3 was 1.2% at 70 bar
This is due to the fact that in NF and reverse osmosis (RO), the solute flux is described by Js = B.∆cs where B is the solute permeability coefficient

Summary

Introduction

Natural gas is a nonrenewable energy source that usually contains undesirable species such as hydrogen sulfide (H2S), and carbon dioxide (CO2), which as well as being harmful to human health cause problems such as corrosion, plugging, freezing, erosion, and environmental hazards [1,2,3,4,5,6]. The maximum concentrtions of the dominant anionic components in amine solvents are as follows: sulfate—500 ppm; acetate—1000 ppm; glycolate—500 ppm; oxalate—250 ppm; formate—500 ppm; chloride—500 ppm respectively [13,14]. The accumulation of these salts in amine solution leads to a reduction in the efficiency of the CO2 absorption process and operational problems such as corrosion, fouling, foaming, high viscosity, capacity reduction [15,16,17,18]. Various technologies that can be used to remove HSS ions from amine solvent include electrodialysis, thermal reclamation, ion exchange and distillation [19,20,21,22]

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