PTQ Q1 2023 Issue

reactor is represented by a series of small discrete segments. In each segment, the progress of each reaction is represented by.km,m:

ΔC a = – C a

n C

b m k

app Δt,

Δx

where Δx = fractional depth in reactor (a segment), n, m = reac- tion order, Δt = residence time per segment = 3600 x catalyst volume/hourly gas rate. All reac- tions are solved in parallel in each reactor segment, and overall con- version is summed across all reac- tor segments. Figure 6 shows the user interface. The model presented here cap- tures not only the detailed reac- tion kinetics but also accounts for deactivation from ageing (depend- ing on temperature, humidity, and

Figure 6 Hydrogenation reactor model interface in OGT SulphurPro

time) and poisoning (related to operational stresses, such as BTEX or O 2 in feed). Hydrothermal ageing affects the rel- ative activity of an entire bed, whereas poisoning impacts the bed along the flow path, starting at the inlet and mov - ing toward the outlet. Poisoning accelerates performance decline, related to loss of conversion of sulphur species that slip through the TGU into the thermal oxidiser. Sound technical tools, which represent the kinetics of the TGU system and enable meaningful simulation, help to reveal substantial effects on performance Conclusions Sound technical tools, which represent the kinetics of the TGU system and enable meaningful simulation, help to reveal substantial effects on performance, allowing a potentially serious event to be identified and mitigated before it happens. With kinetics and deactivation elements considered, one can use the model to analyse and predict the performance and useful life of a real reactor based on a comparison of simulated versus actual temperature profiles, especially over time. Designers will have a tool to better specify reac- tors, and operators will be able to better quantify what is actually occurring instead of only simulating ideal operation. Improved operation and better designs can reduce sulphur emissions, improving the quality of life on our planet.

Gas Catalyst Performance , Brimstone 2013, Sulphur 2014. 2 Maldonado F, Krueger K, Huffmaster M, Low Temperature Tail Gas: kinetic functions – what they are – really , Brimstone 2016. 3 Lavery C B, Sui R, Loftali-Kazemi M, Marriott R A, Kinetic Studies for the Hydrolysis of CS 2 and COS across the Claus Catalytic Converters, Alberta Sulphur Research Ltd, Brimstone, 2019.

SulphurPro is a mark of Optimized Gas Treating, Inc.

Michael A Huffmaster consults to industry on sulphur recovery, treat- ing, gas processing, advanced control, and CO2 capture, and has con- tributed to numerous publications and presentations on these topics. His career includes 17 years as a consultant after 36 years with Shell. He holds a BSc degree in chemical engineering, and is a registered P.E. in Texas. Prashanth Chandran is Software Development Team Lead at Opti- mized Gas Treating, Inc. He holds a B.Tech in chemical engineering from Anna University, India and a MS in chemical engineering from Oklahoma State University. Nathan A Hatcher served as Vice-President, Technology Develop- ment for OGT from 2009. For most of his career, he has been involved with some facet of gas treating and sulphur recovery. He holds a BS in chemical engineering from the University of Kansas, is a registered professional engineer in the state of Kansas, and currently a member of the industry Amine Best Practices Group. Daryl Jensen is a Development Engineer at OGT, experienced in de - sign/development, simulation, basic engineering design package proj- ect execution, process control design, and on-site start-up/trouble - shooting. He holds BS and MS degrees in electrical engineering from New Mexico State University and is a registered professional engineer in Texas. Ralph H Welland formed Optimized Gas Treating in 1992. He was OGT’s original President and now serves as Chairman. He holds BASc, MASc, and PhD degrees in chemical engineering from the University of Toronto, and was a post-doctoral fellow in applied mathematics at the University of Western Australia.

References 1 Huffmaster M, Maldonado F, T ime and Temperature Effects on Tail

PTQ Q1 2023