November 22, 2024
Seyed Abdollatif Hashemifard

Seyed Abdollatif Hashemifard

Academic Rank: Associate professor
Address: .
Degree: Ph.D in مهندسی شیمی
Phone: 09177755574
Faculty: Faculty of Petroleum, Gas and Petrochemical Engineering

Research

Title
Removal of heat stable salts from methyldiethanolamine (MDEA) aqueous solution using anion adsorptive membranes
Type Thesis
Keywords
نمك هاي پايدار حرارتي (HSS)؛ تصفيه متيل دي اتانول آمين (MDEA)؛ غشاي جاذب؛ نانوكربن فعال
Researchers seyed hosein mosavi (Student) , Seyed Abdollatif Hashemifard (Primary advisor) , Mohsen Abbasi (Primary advisor)

Abstract

In the process of removing acid gases using alkanolamines in gas refineries, undesirable Heat stable salts (HSS) are irreversibly formed as a result of the reaction between amines and strong organic acids in absorption and stripping towers. The regeneration of these salts in the stripping tower is not easily achievable, leading to amine degradation. This phenomenon not only results in the loss of consumed amine but also causes issues such as increased viscosity of the amine solution, increased foaming, corrosion, and ultimately a reduction in the capacity for acid gas loading. These problems necessitate the replacement of the degraded amine with fresh amine. Various methods exist for the removal of these salts from the amine solution. In this thesis, an adsorptive membrane method, combining activated carbon nanoparticle adsorption with a polyethersulfone UF membrane, was used to remove the anions of heat stable salts from an aqueous solution of methyl diethanolamine (MDEA). Initially, two types of activated carbon, Merck 102186 and Norit GAC 830W, were converted into nanoscale particles using a ball milling method. BET analysis and equilibrium adsorption test were conducted to identify the best adsorbent in a 40 wt% MDEA solution. Subsequently, membranes were fabricated using phase inversion method with suspensions containing activated carbon nanoparticles at ratios of (0, 0.5, 1, 1.5, and 2) relative to the polyethersulfone (PES) polymer. The synthesized membranes were characterized using SEM, AFM, FTIR, and STA analyses to examine their structure and morphology. Additionally, the membranes were analyzed with descriptive tests including porosity and mean pore size calculations, contact angle measurement, and pure water and pure amine flux tests. By performing batch equilibrium adsorption using the membranes, the Langmuir and Freundlich isotherm models accurately described the adsorption behavior of HSS, with the highest Langmuir adsorption capacity (q_m=22.63 mg/g)