Membrane based triethylene glycol separation and recovery from gas separation plant wastewater | |
| Author | Pimchanok Khachonbun |
| Call Number | AIT Thesis no.EV-13-22 |
| Subject(s) | Gases--Separation Membrane separation Water--Purification--Membrane filtration |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Environment Engineering and Management |
| Publisher | Asian Institute of Technology |
| Abstract | Triethylene glycol (TEG) is absorption, involves the use of a liquid desiccant to remove water content from the gas. This study investigated membrane filtration, pervaporation process and design pre-treatment process to treat real wastewater from gas separation plants. In membrane filtration experiment, four types of membrane (NF-TS40, NF-TS80, RO-ACM5 and RO-NTR759HR) were tested with synthetic wastewater. NF-TS80 is the best of nanofiltration membrane to recover TEG, with a 70% TEG recovery. Moreover, RO-ACM5 was the most effective membrane of reverses osmosis membrane, with a 90% TEG recovery which presented at low concentration applied (0.1%, 5% and 10% of TEG). In case of permeate flux, the low permeate flux (0.01-0.16 L/m².h) presented at high concentration applied (20% and 30% of TEG) that was resulted from the effect of concentration polarization and membrane fouling. Pervaporation process was conducted with 0.1, 5 and 10% of TEG concentrations in synthetic wastewater with temperature variation of 30, 40 and 70°C of each concentration. In case of permeate flux, the high permeate flux 6.81 kg/m².h presented at low concentration (0.1% of TEG) and used high temperature (70°C). While the permeate flux at a concentration of 10% was found with 0.58 kg/m².h at 40°C. Also, the separation factor was 698 for 10% TEG at 40°C. The flux and the separation factors obtained indicate that pervaporation process with NaA Zeolite membrane is not attractive and the system does not performed well at lower concentration of solutes. In pre-treatment experiment, testing with real wastewater using RO-ACM5 and NF-TS80 membranes was necessary. However, the wastewater first needs be pretreated to protect membrane from fouling by suspended solids and oil/grease by used microfiltration (MF) and ultrafiltration (UF) membrane, respectively. Pre-treatment process coupled with nanofiltration membrane (TS80) showed higher TEG removal than synthetic wastewater experiments at 0.1% TEG concentration by approximately 73%. While reverse osmosis membrane (ACM5) showed slightly higher removal for TEG than synthetic wastewater experiments with 0.5% TEG concentration also by approximately 95%. In case of 8.3% TEG concentration, nanofiltration (TS80) and reverse osmosis (ACM5) membrane showed relatively equal to the value of synthetic wastewater experiments by approximately 47.15% and 77.56%, respectively. Therefore, the pre-treatment process should be applied before using membrane filtration with NF and RO membrane which are proposed for industrial applications due to its high removal efficiency, high permeate flux with low TEG concentrations. |
| Year | 2013 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Environmental Engineering and Management (EV) |
| Chairperson(s) | Visvanathan, C.; |
| Examination Committee(s) | Annachhatre, Ajit P.;Romchat Rattanaoudom; |
| Scholarship Donor(s) | Royal Thai Government;Asian Institute of Technology Fellowship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2013 |