Flare Mitigation Approach during Abnormal Process Operations By Integrating Thermal Membrane Distillation Networks and Cogeneration Unit for an Existing Process Plant

Flare Mitigation Approach during Abnormal Process Operations by Integrating Thermal Membrane Distillation Networks and Cogeneration Unit for an Ethylene Process Plant

Monzure-Khoda Kazi, Fadwa Eljack^*

Department of Chemical Engineering, College of Engineering,

Qatar University, P.O. Box-2713, Qatar

Email: Fadwa.Eljack@qu.edu.qa

Flared gas from an ethylene process plant can be used as valuable energy source when properly harnessed. Usually, ethylene plants are not interested about these enormous energy sources due to the lack of proper flare management system and appropriate integration. Moreover, these process plants use extra heating/cooling utilities and waste water treatment plant to reduce the contamination of their downstream to satisfy the environmental regulations. These extra costs can be minimized if proper integration is possible within the process itself. Using cogeneration (COGEN) and thermal membrane distillation (TMD) unit with industrial processes can offer a potential scope of process and energy integration and can also offer the maximum utilization of flared gas streams. Cogeneration is an improve process integration where dual industrial process requirement of power and heating can be satisfy using same fuel. Furthermore, the low-level heat produced in the process and cogeneration can be transferred to a TMD unit, which is an emerging technology in the area of high-purity separation especially in water treatment (Elsayed et al., 2013). Produced water from TMD can be recycled in the process or sold to external users. There is scope to integrate cogeneration unit and thermal membrane distillation networks with the ethylene process plant to manage flares from abnormal process operations.    

This work has proposed a multi-objective optimization methodology for simultaneous energy integration, cogeneration sizing, and TMD networking. An ethylene base case study is solved to illustrate the applicability of the proposed methodology. The results of different scenarios demonstrate the benefits of integrating TMD and cogeneration unit with the process plant for flare mitigation approach. It will ensure the maximum use of flared gas streams, reduction of cooling utility load and the creation of recycle/reuse opportunities for the treated waste water.

Reference

Elsayed, N. A., Barrufet, M. A., & El-Halwagi, M. M. (2013). Integration of Thermal Membrane Distillation Networks with Processing Facilities. Industrial & Engineering Chemistry Research, 53, 5284-5298.