20-03-2018

Latest developments in sour hydrocarbon treatment to be covered at SOGAT 2018

Sulphur management encompasses all aspects of sour hydrocarbon conditioning and dominates the current thinking and planning in the Middle East region and non more so than in the UAE . Here recent FEED contracts have been awarded for the Hail,  Ghasha the Dalma  ultra- sour fields . Known collectively as the North-West Area, the three fields tap into Abu Dhabi’s Arab formation, which is estimated to hold multiple trillions of cubic feet of recoverable gas. Thus this activity will contribute significantly to ADNOC plans to enhance gas requirements and production of sulphur in the coming years

Sulphur production however has it pitfalls as witnessed by ADNOC Gas Processing HSE’s department in studying  the implications of sulphur dust which is an underrated risk component in sour operations . They noted since the commissioning of Etihad Rail as transportation mode for solid sulphur, a new phenomenon of increased sulphur dust generation was observed. The phenomenon corresponds to transportation and handling of granulated sulphur to the shipping terminals from two of the ADNOC’s distantly located Sulphur Granulation plants. They undertook Fire and Explosion Risk Assessment studies to deal with this new challenge. In the light of sulphur dust incidents experienced, they were able to provide insights on the improvements that can facilitate the smooth operation and maintenance of sulphur handling units to improve and avoid these incidents and will present them exclusively at SOGAT 2018  . Other problems with sulphur are encountered in gas transportation , sulphur handling and  refinery operations with sulphur deposition and slugging and ARKEMA will be launching SULFA-TEK at the SOGAT  2018 Exhibition . SULFA-TEK is a new and powerful tool to help the maintenance and cleaning operations when these scenarios occur .

Khalifa University who have been conducting research on issues experienced in the exploitation of sour reservoirs with high concentrations of H2S in the raw well fluids found  that it can  pose significant health, safety and environmental threats. Employing atmospheric gas dispersion modeling is a vital component of mandatory hazard assessment, which can provide critical input data to the design of hazardous gas sensor networks, development of emergency response plans to hazardous gas releases, and post-hazard investigations and they will share their findings of this modeling approach at the SOGAT conference .
 
Another vital component of sour hydrocarbon conditioning is the correct use of Sulphur Recover Units (SRU’s) and KTI  S.p.A. from  Italy will demonstrate  how to increased sulphur processing capacity of an existing refinery  plant . Environmental regulations  around the world are becoming more stringent imposing the production of fuels with lower sulphur content. On the other hand, the trend shows that in the refineries the crudes treated are always more sour, increasing the quantity of sulphur that must be removed in the refinery processes. In addition, also the emissions of SO2 from most  industrial complexes are now strictly monitored and limited to challenging values. These factors require the need to treat higher quantities of H2S recovering it into elemental sulphur. They will show that the best solution for sulphur processing capacity is by employing their proprietary RAR technology which effectively and economically improved the Gas Sweetening and Tail Gas Treatment aspects of the process .  Also ADNOC Sour Gas will present  their test run results with optimizing the fuel gas co-firing in SRU reaction furnaces. This additional capacity in SRU has helped the overall gas plant operate at 110% of the original design as well as provided additional availability of the gas plant at 86% capacity against the original design of 75% in case of one SRU shutdown. This has increased the overall gas plant profitability . Similarly Sulphur Recovery Engineering (SRE) from Canada will provide guidelines  for operators to achieve their recovery efficiency license requirements and to ensure that their SRUs are operating reliably and efficiently.  In achieving this mandate, SRE conducts onsite sampling, analyses and operational recommendations for SRUs worldwide.  The main service performed is an SRU performance evaluation and they will describe what benefits a performance evaluation can deliver to the operator.  The advantages apply to all stakeholders of the SRU including Operations, Maintenance, Management and Environmental personnel.

The  industry is increasingly pursuing compact and low weight processing technology to meet the technological and economic demands of offshore, onshore, remote, and challenged gas processing. ExxonMobil has developed the Compact Mass transfer and Inline Separation Technology (cMIST) gas treating system, a novel, compact and low weight processing technology platform, to achieve process intensification in processing facilities .The incentives include lower size, weight, solvent circulation and cost compared to a conventional amine system.  For applications where H2S removal is integrated with sulfur recovery, the additional potential benefit of the cMIST system is the elimination of the Acid Gas Enrichment (AGE) unit due to high H2S purity in the acid gas. The technology is highly modular to allow for simple transportation into remote, challenged, or offshore environments and provide installation configuration flexibility. They  will also demonstrate how it is also beneficial for debottlenecking and capacity enhancement applications.

A major aspect of the event will be the  presentation on research work conducted for producing hydrogen from H2S in SRU’s using an innovative chemical process of H2S methane reforming in a similar fashion to the well-known water shift reaction between water and methane. Specifically, the process is designed to process a sour gas stream from one of the sweetening units in the UAE. While in conventional SRU’s, valuable hydrogen is wasted, methane reforming will allow the recovery of sulfur products and hydrogen simultaneously. This has the  potential to become a revolutionary idea of simultaneously recovering sulphur from H2S while generating hydrogen as a fuel. The proposed design work involves cryogenic separation of carbon dioxide and water from the hydrogen sulfide feed, implementation of a membrane reactor and product separation. The high energy requirement of the process makes the exploration of renewable energy sources worthwhile such as the use of solar reactors. Overall, the methane reforming process was found to have a potential in recovering hydrogen from hydrogen sulfide and can possibly and ultimately replace the Claus process units which has always been used as the conventional sulfur recovery process. Indeed, this justifies the need for further exploration of this process, especially its reaction kinetics , process energy requirements and their implementation in a membrane reactor. Additionally, a viable economic model will be generated to evaluate economic feasibility of this process .

Another innovative aspect  presented at SOGAT 2018 will be Air Products ability in low temperature gas separations and its interest in recovery and purification of helium and CO2 from sour natural gases  experience  in North America . This led on to develop a distillation based sour gas processing scheme including a novel, efficient distillation technology for bulk separation of CO2 and H2S from sour natural gas by condensation and distillation followed by separation of CO2 and H2S by their advanced distillation process that can efficiently and cost effectively produce concentrated H2S for reinjection as a pumped liquid  if required and pure CO2 for enhanced oil recovery at elevated pressure. This latter aspect is important to ADNOC as they plan to expand their use of Carbon Capture, Use and Storage ( CCUS) technology to meet a six fold increase in using CO2 for EOR over the next decade . These  CCUS plans in detail will be laid out by ADNOC Gas Processing.

Amine units are crucial for removal of H2S and CO2 from the gas streams. Any failure in these units can lead to unavailability of the plant and may have substantial economic consequences. Therefore it is essential that potential degradation threats are recognised, understood and properly managed. SRE will discuss typical materials of construction, typical corrosion loops, potential degradation mechanisms for different types of amine and recommended integrity operating windows as well as give guidelines on how to overcome current operational problems such as foaming.
 
As previously mentioned  treatment in oil and gas fields, refineries and chemical facilities is getting more complex due to stringent emissions requirement.  While the conventional acid gas removal systems based on amine scrubbing and caustic treatment are highly effective in removing H2S, these technologies are not highly effective for complex organo-sulfur compounds such as complex mercaptans , sulfides, thiophenes and disulfides and how this situation can be improved will be demonstrated to remove such complex contaminants  by US based company , Sulfatrap.
 
A very important consideration in today’s market is plant energy efficiency and management and recent beneficial work from ADNOC Gas Processing will show how energy savings initiatives have been arrived at to achieve ADNOC’s  2020 target of reducing energy consumption by 10 % and how they are being implemented in their Bu Hasa plant . Energy Recovery Inc  based in California will also show how their hydraulic turbocharger system, known as IsoBoost for AGR , operating at 6000 gpm at a major GCC facility was capable of saving 12,000 MWh annually and they expect multiple such units to be installed in this coming year thus making significant energy savings for the NOC concerned .

All these issues and many other case histories  especially in the highly practical  pre-conference workshops will be covered in this year’s event  and more will be found at www.sogat.org