Ensuring Safety through Flexibility Enhancement of Amine Unit Operation

Abstract Limitations in Amine storage capacities at one of GASCO's Plants necessitates the use of temporary ISO-Storage containers to store surplus Amine during Plant / Process shutdown. This poses serious risks to equipment and personnel safety which could be categorized as a safety critical issue. This paper addresses the study carried out to resolve the issue, exploring various options and how the proposed solution mitigates the risks and ensures process safety by enhancing operational flexibility of the amine unit. Optimization of the Plant layout for HSE constraints resulted in location of amine regeneration section farther away from the amine unit, leading to an increase of solvent inventory above design levels. As a result, during shutdown operations, the existing storage capacity was deficient by a significant margin, necessitating use of temporary facilities to overcome the shortfall. A study was carried out to find solutions to the issue and various options were explored. Limited availability of space in an existing Plant, working within hazardous area and tie-ins with existing processes posed several challenges. The entire study was carried out utilizing GASCO's in-house resources involving full spectrum of discipline engineering expertise. The selected option involved provision of an additional storage tank and associated facilities. This included identification of the required tank sizing and storage capacity, feasible location of tank and transfer pump, feasibility study of pipe routing and tank bund containment calculations. The following benefits will be achieved with the proposed solution: - Safe access for operation/maintenance. - Proper containment of spillages / leakages within the tank bund. - Nitrogen blanketing to stop H2S release and reaction of lean amine with oxygen. - Venting (routed to a safe location). - New lean amine tank will have fixed firefighting foam system. - Use of fixed 6 inch line instead of hose for lean amine transfer. - Shutdown delays will be avoided. - Process contamination will be avoided. As the proposed location was within the hazardous area close to live Plant units, tank installation was required to be carried out within the shutdown period. This triggered the development of a novel approach for a modular fabrication of tank, transportation in parts and installation strategy, to maximize pre-shutdown activities and enable optimum use of shutdown duration for the installation. Accordingly, study addressed this concern through extensive interaction with tank fabricator and recommended suitable methods. Modular fabrication and installation of a new tank within live process units to ensure reliable and safe operations, is a novel approach to addressing the solvent storage issue. This approach will also avoid delays and extended shutdown duration.