6 November, 9:00 am
The most popular form of sulfur plant tail gas treatment is to utilise an amine based system. When working properly, these systems will minimise the amount of hydrogen sulfide (H2S) being burned in an incinerator, thus minimising the amount of sulfur dioxide (SO2) being emitted by the plant. The amine process removes H2S from the tail gas, along with a small amount of carbon dioxide (CO2), and recycles it back to the sulfur recovery unit (SRU) for reprocessing.
One of the most serious operational problems in an amine based tail gas treating unit (TGTU) is ‘foaming’ in the absorber.
Foaming is often the product of a chain of events that starts as early on as the reaction furnace of the SRU. If the H2S:SO2 ratio is too low, or if the reducing gas generator is not functioning properly, or if there are operational problems in the hydrogenation reactor then SO2 can break through the reactor and contaminate the quench water.
The topic of this paper is how Amine Experts has solved this problem using specific testing, analytical and operational strategies. No proprietary techniques were used; these strategies could be adopted by any TGTU operating companies.
Sulfur recovery units (SRU) convert unwanted hydrogen sulfide (H2S) and sulfur dioxide (SO2) to the desired element, sulfur. This is done most often using the Claus process. SRUs are essential parts of refineries, smelters, and natural gas plants, where large amounts of H2S are produced. The quality of the Claus catalyst is critical for maximising the performance of the SRU. BASF’s extensive product line of Claus catalysts provide the superior value that is needed.
BASF offers an extensive line of Claus catalysts. Along with non-promoted and promoted activated alumina, there are two different titania catalysts along with a alumina/titania hybrid catalyst. Two types of active bed supports (ABS) with diameters ranging from 0.12 in. to 0.5 in. are also available.
Activated alumina catalysts:
- S-100 SR (promoted).
- DD-831 (promoted).
Characteristics of BASF Claus catalysts:
- Large number of accessible surface active sites for H2S and S20 to react and form sulfur and water (high surface area).
- Good large pore volume distribution (high macroporosity).
- Low bulk density that directly lowers catalyst expense.
- Low abrasion and high strength which minimises dust and fines.
- Uniform size and shape for lower pressure drops.
Blasch Precision Ceramics
Blasch Precision Ceramics is an advanced refractories company specialising in the design and manufacture of close tolerance, complex net shapes and strives to take an engineering problem solving approach to improving refractory performance.
Blasch is able to do this by utilising a proprietary injection molding process that allows for almost complete freedom of design, and yields components exhibiting exceptional thermal shock resistance and remarkable consistency, in terms of physical properties as well as dimensional tolerances.
Blasch developed the precast one and two piece hexagonal and square head ferrule systems in response to requests from the field to address cracking in large tubesheets utilising the traditional round ferrule and castable approach. Blasch was able to design a system that utilised individual precast ferrules that are carefully sized to allow for repeated thermal cycling without the buildup of stresses that one would find in a monolithic castable or mortared ferrule system.
The Blasch VectorWall™ was initially developed in response to repeated requests to develop a precast refractory checkerwall that was mechanically stable over the long run in a variety of sizes and in even the highest temperatures. It quickly became apparent that the VectorWall offered significant process improvement tied directly to more efficient use of furnace volume, and the creation of the most appropriate flow configuration for the type of furnace under review.
The VectorWall checkerwall consists of a series of hexagonally shaped blocks that lock together through the use of a series of tabs and slots to provide considerable mechanical advantage. Easy to install and reusable, the VectorWall has proliferated quickly and steadily into Claus trains worldwide.
Field results show consistent gains on the order of 30 - 50% in furnace throughput, and greatly improved ammonia destruction.
Controls Southeast Inc.
Controls Southeast Inc. (CSI) specialises in engineered thermal maintenance solutions for refinery and petrochemical applications. In sulfur recovery units (SRU), CSI has products and solutions for heating liquid sulfur lines, sulfur vapour lines and above ground sealing. In liquid sulfur pump lines, CSI’s ControTrace™ and ControHeat™ products replace expensive and complicated jacketed piping. In sulfur vapour lines, the ControTrace product is applied instead of tube tracing. This product maintains a minimum pipe wall temperature and prevents corrosion from occurring in tail gas applications. ControTrace can also be applied externally to tanks and vessels. The widespread application of these products around the world has made CSI the industry standard heating technology in SRUs. CSI provides three products for sulfur sealing: seal legs, and the SxSeal 1000 and 2000, which are above ground sealing devices.
In heavy resid applications, CSI products provide more reliable, faster melt out capability and lower cost solutions compared to standard tube tracing. This has saved cost in the use of flushing oil and in the ability to recover more quickly from upset events and thereby getting in more coking cycles during the year than they would otherwise.
Duiker Combustion Engineers
Duiker Combustion Engineers has earned a reputation as a leading name in process combustion technology since it began supplying equipment to the petrochemical industry during the 1950s. Its main activities include designing, supplying and installing a range of gaseous and liquid fuel process burners for oil refining, chemical and natural gas processing applications. It provides a comprehensive range of equipment including burners, vessels, waste heat boilers, burner management systems and instrumentation. Whatever the project, the company’s expert team of engineers is dedicated to delivering cost effective, environmentally friendly and uniquely tailored solutions.
During the 1950s the company’s original portfolio included mainly in line, reducing gas generator and incinerator burners. However, as the company has progressed its global experience and technology focused innovation have allowed it to further push the limits of burner design for a range of applications including normal air, enriched air and pure oxygen. Duiker is committed to investing in the development of new technologies and currently has five dedicated research and development engineers as well as a fully functioning in house test facility for burners and associated equipment.
Resulting from the industry trend towards super heavy oil, Duiker has developed a patented technology that allows the processing of ammonia outside of sulfur recovery units (SRUs). This stoichiometry controlled oxidation process can reduce the capital investment in a grass roots sulfur recovery unit by 10% and is also very suitable for debottlenecking existing plants. In Paris, Duiker shall be showcasing this technology and more.
DuPont Sustainable Solutions
MECS, Inc. (MECS), a wholly owned subsidiary of DuPont, is part of DuPont Sustainable Solutions, a consulting and technology services business that helps organisations address complex business and market realities through integrated offerings. MECS is a world leader in the design of new sulfuric acid plants and revamps of existing sulfuric acid plants. In addition, MECS provides proprietary equipment and replacement products for the sulfuric acid industry: catalysts, acid coolers, acid piping systems, tanks and towers, and ZeCor® corrosion resistant alloys. MECS is also a well known supplier of OCAP® and MonPlex™ plate heat exchangers, Brink® mist eliminators and DynaWave® scrubbers in sulfuric acid and other industries. At Sulphur 2014, MECS will be highlighting technology solutions available to meet increasingly stringent environmental regulations, as well as efficient and reliable acid plant operator training.
Adapted for the web by Emma McAleavey.
Read the article online at: https://www.hydrocarbonengineering.com/gas-processing/08102014/sulphur-show-preview-1369/