Developing minimum liquid discharge strategies for Bangchak Oil refinery's RO plant | |
| Author | Apinun Pipatparnukul |
| Call Number | AIT Thesis no.EV-18-03 |
| Subject(s) | Petroleum refineries Water--Purification--Reverse osmosis treatment |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Environmental Engineering and Management |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. EV-18-02 |
| Abstract | The Bangchak oil refinery’s RO water treatment plant (Thailand) has been in operation since 2015. The water reuse system combines media filtration with the combination of double phase of microfiltration (MF) and reverse osmosis (RO) to recirculate water to use in cooling tower system. The current RO system salt rejection is still above 85% at 50% designed water recovery. The first phase of this study is water audit. Water audit was conducted to understand the performance of Bangchak oil refinery’s RO water treatment plant in terms of the balance of water and salt (TDS). The audit results indicated that there was not significant operation problem in the plant because difference of input and output of water and salt are lower than 10%. The main reason for imbalance is friction loss in the pipe line, membrane degradation, instability of applied pressure and inaccurate flow rate and conductivity meter. Currently, the large amount of RO concentrate (360 m³/day) ware discharged without any further recovery process. Pilot scale of Minimum Liquid Discharge (MLD) system was designed in this study to recovery discharged wastewater as much as possible. The MLD system was divided into 2 options namely, Double stage of RO systems with chemical precipitation and A single stage of RO and electrodialysis (ED) system. For the results of both MLD systems, the performance of MLD system option 1 and system 2 can achieve with 87.5 % and 95 % of water recovery respectively. The quality of permeate water was good enough to recovery back to cooling tower system. With the proposed MLD systems, the engineering design of both MLD systems was designed to achieve 75 % and 90 % of overall water recovery with 360 m³/day. The initial cost investment of MLD system 1 and MLD system 2 are 12,071,000 Baht and 28,288,000 Baht respectively, while O&M cost of both MLD systems are 29 Baht/m³ and 64 Baht/ m³. Hence, the MLD system 2 might be not very attractive from industry’s point of view because of very expensive, while the MLD system 1 is likely to be appropriate to apply in Bangchak’s RO water treatment system. |
| Year | 2018 |
| 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 (EV) |
| Chairperson(s) | Visvanathan, C.; |
| Examination Committee(s) | Thammarat Koottatep;Mohanty, Brahmanand; |
| Scholarship Donor(s) | The Bangchak Corporation Public Company Limited, Thailand; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2018 |