Beavon Sulfur Removal process

Beavon, D. K. Fleck, R. N., "Beavon Sulfur Removal Process for Claus Plant Tail Gas" Sulfur Removal and Recovery from Industrial Processes 1975, Advances in Chemistry 239. 

Beavon Sulfur Removal Process for Claus Plant Tail Gas... 

The Beavon sulfur removal process for the cleanup of Claus plant tail gas is a two-step process in which the sulfur contaminants are first catalytically hydrolyzed and/or hydrogenated to hydrogen sulfide and the hydrogen sulfide is then converted to elemental sulfur and recovered in a Stretford process unit. Commercial plants reduce the concentration of sulfur compounds as hydrogen sulfide in the tail gas from 1-3 vol % to less than 100 ppm. The treated gas contains less than 1 ppm hydrogen sulfide. The chemistry, design criteria, operating experience, and economics of the process are discussed. 

A number of commercial plants are now using the Beavon sulfur removal process to convert the sulfur content of Claus tail gas first to hydrogen sulfide and finally to elemental sulfur. These plants reduce the sulfur content of the tail gas from about 1—3% to less than 100 ppm of which less than 1 ppm is present as hydrogen sulfide. The foregoing con-... 

Pilot Plant. The Beavon sulfur removal process was studied in a pilot plant where the scale-up factor was 100 and 200 for the first two commercial units. General process operability was established at this stage. 

Figure 1. Flow diagram of the Beavon sulfur removal process...

Table I. Beavon Sulfur Removal Process Operating Costs" ...

The Beavon sulfur removal process is now a reliable, established method for cleaning up Claus plant tail gas well beyond any proposed regulations. As with any new process, work is currently directed toward reducing capital and operating costs. The capital investment has already been reduced by about 20% over the original design. A further cost reduction now seems possible, thereby increasing the application possibilities of this process. 

Like the Scot process, the BSR BEAVON Sulfur Removal Process) developed by R.M. Parsons Cie. and Union Oil Company of California hydrogenates all sulfur components of the Claus tailgases to H2S. The H2S is then removed in a Stretford unit (see Sect. 2.3.3) to obtain elemental sulfur. The clean offgases from the Stretford unit contain less than 200ppm residual sulfur and less than 5 ppm H2S. 

Hgute 8-28. Typical process flow diagram—Beavon sulfur removal process using Stretford process for H2S removal. 

Figure 8-29. Beavon sulfur removal process plant. Courtesy The Parsons Corp.

Andrews, E. J., and Kouzel, B., 1974, Beavon Sulfur Removal Process Eliminates Sulfur in Claus Plant Tail Gas, paper presented at 53rd GPA Annual Convention, Denver, CO. March 25-27. 

Beavon, D. K., and Brocoff, J.C., 1976, Recent Advances in the Beavon Sulfur Removal Process and the Stretford Process, paper presented at the Second International Conference of the European Federation of Chemical Engineers, University of Salford, England, April 6-8. 

Fenton, D. M., Woertz, B. B., Brocoff, J. C., and Jirus, E. J., 1975, Tail Gas Clean-up With the Beavon Sulfur Removal Process, paper presented at NPRA Annual Meeting, San Antonio, TX, March 23-25. 

Kouzel, B., Fuller, R. H., Jirus, E. J., and Woertz, B. B., 1977, Treat Low Sulftn Gases with Beavon Sulfur Removal Process and the Improved Stretford Process, Gas Conditioning Conference Proceedings, University of Oklahoma, Norman, OK, March 7-8. 

Beavon, D. K., 1973, The Beavon Sulfur Removal Process, Proceedings International Conference on Control of Gaseous Sulphur Compound Emissions, University of Salford (Brit), Vol. 1, April 10-12. 

Beavon [Beavon Sulfur Removal] Also called BSR. A process for removing residual sulfur compounds from the effluent gases from the Claus process. Catalytic hydrogenation over a cobalt/molybdena catalyst converts carbonyl sulfide, carbon disulfide, and other... 

Reductive Tail Gas Treatments. It was largely as a result of the effort to achieve better than 99% recovery that the reductive tail gas desulfurization processes (46) were developed in the 1970 s. The two main methods are the Beavon Sulfur Removal (BSR) (47) and the Shell Claus Off-Gas Treatment (SCOT) (48) processes. Both of these processes are now widely used as tail gas desulfurization units on sulfur recovery plants and can readily achieve point source emission levels below 250 ppm and below 100 ppm if necessary to meet regulatory standards. 

Beavon Also called BSR [Beavon Sulfur Removal], A process for removing residual sulfur compounds from the effluent gases from the Claus process. Usually used in conjunction with other processes. Catalytic hydrogenation over a cobalt-molybdena catalyst converts carbonyl sulfide, carbon disulfide, and other organic sulfur compounds to hydrogen sulfide, which is then removed by the Stretford process. A variation (BSR/MDEA), intended for small plants, uses preliminary scrubbing with methyl diethanolamine. Developed by the Ralph M. Parsons Company and Union Oil Company of California in 1971. More than 100 plants were operating in 2000. See also SCOT. 

Several processes have been developed based on the oxidation approach, but, with some exceptions, such as the Linde Clintox process (Heisel and Marold, 1992) these have not been commercial successes because of the complexity of SO2 recovery processes and their comparatively low SO2 removal efficiencies. Hydrogen sulfide, on the other hand, can be removed at very high efficiency by a number of processes, including the selective amine processes discussed in Chapter 2. Processes that involve the conversion of Claus plant tail gas sulfur compounds to H2S and the removal of this H2S are discussed in the following sections. Processes reviewed include Parson s Beavon Sulfur Removal (BSR) process. Shell s SCOT process, FB and D Technologies Sulften process, the TPA Resulf process, and the Exxon Flexsorb SE Plus process. 

Introduction. The Beavon Sulfur Removal (BSR) process, as repotted by Beavon and King (1970) and Beavon and Vaell (1971), is capable of reducing the total sulfur content of Claus unit tail gases to less than 250 ppm by volume (calculated as sulfur dioxide) and thus of attaining an overall conversion of more than 99.9% of the hydrogen sulfide fed to the Claus unit. The residual sulfur compounds from the Beavon process consist almost entirely of carbonyl sulfide, with only traces of carbon disulfide and hydrogen sulfide. The effluent gas is practically odorless and can often be vented directly to the atmosphere, obviating the need for incineration and the attendant consumption of fuel. 

The Beavon Sulfur Removal (BSR) process was developed jointly by the Parsons Coip. of Pasadena, California, and the Union Oil Company of Califoinia (now Unocal Corporation of Los Angeles, California). The term Beavon process refers to a group of processes utilized for the removal of residual sulfur compounds from Claus plant tail gases. This family of processes has in common an initial hydrogenation and hydrolysis unit to convert all residual sulfur compounds to H2S. Individual processes within this family differ from each other in the technology used to remove the H2S from the Claus tail gas stream. Process improvements and operating experience have been reported by Andrews and Kouzel (1974). Fenton et al. (1975), Beavon and Brocoff (1976), and Kouzel et al. (1977). 

I en percent of the regenerator offgas is purified in a Wellman-Lord unit, and the concentrated sulfur dioxide from this unit is added to the remaining 90% of the gas which is then processed in a BSRP system. The Wellman-Lord process is described in Chapter 7. The BSRP system consists of a Beavon Sulfur Removal (BSR) unit to convert all sulfur compounds to hydrogen sulfide (see Chapter 8) followed by a Stretford unit to convert the hydrogen sulHde to elemental sulfur (see Chapter 9). 

Alternative means for removal of carbonyl sulfide for gas streams iavolve hydrogenation. For example, the Beavon process for removal of sulfur compounds remaining ia Claus unit tail gases iavolves hydrolysis and hydrogenation over cobalt molybdate catalyst resulting ia the conversion of carbonyl sulfide, carbon disulfide, and other sulfur compounds to hydrogen sulfide (25). 

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