The US refining sector continues to face operating pressures with 1.3 million bbl/d of closures in the past three years, while sour gas sulphur production has recovered somewhat. Meanwhile, demand from copper and lithium leaching projects will increase use of sulphuric acid over the next few years.
Sulphur processing from sour gas fields dominates regional production, but the geographical remoteness of the area from end use markets and restrictions on sulphur storage means that producers often opt to reinject acid gas into oil and gas wells.
RSK and its subsidiary ADAS have developed a sustainable solution for the disposal of sulphur waste generated from a natural gas processing facility in Iraq. C. Teulon of RSK reports on the research that was carried out to test whether the waste sulphur from a biological sulphur removal process could be applied in agriculture to increase the quality and quantity of crops in Iraq.
Considering the current shift to produce biofuels instead of conventional oil products, M. van Son of Comprimo discusses the impact that this may have on the ability to process the sour water acid gas streams produced in existing or new sour water strippers.
ASRL has conducted studies on ammonia destruction in the sulphur recovery unit (SRU) for over a decade1-5 . Other studies at ASRL have investigated mechanisms for ammonium salt formation and deposition downstream in the Claus plant, as well as the potential sources of ammonia (NH3 )in a gas plant7 . A less understood subject is addressing how much residual NH3 is tolerable or at what temperature will residual NH3 cause ammonium salt deposition. In this study, existing knowledge on thermal stability of ammonium salts and new measurements have been used to identify the gaseous components required for deposition, through reversible vapour pressure expressions.
M. Baerends of Fluor reports on the conception, engineering, construction, commissioning and start-up of a new sulphuric acid plant that replaced an existing acid plant at a European sour gas processing terminal. This highly complex gas processing facility handles sour gas from an off-shore field, containing H2 S that must be removed to meet transmission grid specifications. Various issues encountered, their resolution by the joint owner, Fluor and Topsoe team, and plant operating results are discussed.
Sour gas processing presents a number of unique challenges, especially at high levels of hydrogen sulphide and carbon dioxide content.
After many years of slow decline, Canadian sulphur exports have begun to rise slightly, but dwindling US markets are seeing a move towards more sulphur forming to expand export opportunities.
K. Hanlon Kinsberg and J. Lewis of Comprimo review the main approaches for mercaptan removal in gas processing plants, based on past project experience and generally accepted industry practice.
Fluor’s case study of recently constructed ultra-sour gas treating facilities provides new information about the operation of DGA-based AGRUs. B. Lynch and C. Graham of Fluor Corporation discuss how using this knowledge and leveraging the recent improvements to process simulators in the gas sweetening space, Fluor has developed an efficient, flexible, and cost effective solution in the two-stage absorption process to maximise mercaptan removal from ultra-sour gases with minimal equipment.