Patent ID: 6030597
Filing Date: 2000-02-29
Classification: B01D,B01J,C01B,Y10S

Abstract:
A process for treating a hydrogen sulfide containing feed gas stream to convert the hydrogen sulfide to elemental sulfur, said process comprising:(a) introducing an air stream and said hydrogen sulfide containing feed gas stream into a first reactor comprising a sulfated solid oxide sorbent, said sorbent further comprising a catalytic oxidation promoter, wherein said feed gas stream is contacted with said sulfated solid oxide sorbent under conditions sufficient to convert said hydrogen sulfide and sulfated solid oxide into a product mixture comprising a first vapor phase product and a solid phase product, the rate of said air stream addition being controlled by the temperature of the sorbent, said first vapor phase product comprising elemental sulfur vapor, water vapor and sulfur dioxide, said solid phase product comprising desulfated solid oxide, said first vapor phase product being passed from said first reactor along with unreacted hydrogen sulfide as an effluent, and at least a portion of said solid phase product being retained in said first reactor;(b) passing the effluent from step (a) into a condenser operated under conditions sufficient to condense at least a portion of the elemental sulfur to liquid sulfur, wherein a liquid sulfur product is obtained and a second vapor phase product is formed, said second vapor phase product comprising sulfur and hydrogen sulfide, said second vapor phase product being passed from the condenser;(c) passing the second vapor phase product from step (b) along with a source of oxygen into a burner operated under conditions sufficient to convert substantially all of the sulfur and hydrogen sulfide in the second vapor phase product from step (b) to a combustion product comprising sulfur oxides;(d) passing the combustion product from step (c) into a second reactor comprising a solid oxide sorbent under conditions sufficient to combine said sulfur oxides from step (c) with said solid oxide sorbent in the second reactor, thereby producing a solid phase product and a treated vapor phase product, said vapor phase product comprising less than about 50 ppm of sulfur oxides, said solid phase product comprising a sulfated solid oxide sorbent, said treated vapor phase product being passed from said second reactor and at least a portion of said solid phase product being retained in said second reactor;(e) discontinuing the flow of said feed gas stream into the first reactor;(f) discontinuing the flow of the combustion product from step (c) into the second reactor;(g) introducing said feed gas stream into the second reactor, wherein said feed gas stream is contacted with the sulfated solid oxide generated in step (d) under conditions sufficient to convert said hydrogen sulfide and sulfated solid oxide into a second product mixture comprising a third vapor phase product and a second solid phase product, said third vapor phase product comprising elemental sulfur vapor, water vapor, and sulfur dioxide, said second solid phase product comprising desulfated solid oxide, said third vapor phase product being passed from said second reactor along with unreacted hydrogen sulfide as a second effluent; and at least a portion of said solid phase product being retained in said second reactor;(h) passing the second effluent from step (g) into the condenser of step (b) or into another condenser operated under conditions sufficient to condense elemental sulfur to liquid sulfur, wherein a second liquid sulfur product is obtained and a fourth vapor phase product is formed, said fourth vapor phase product comprising sulfur and hydrogen sulfide, said fourth vapor phase product being passed from the condenser;(i) passing the fourth vapor phase product from step (h) along with a source of oxygen into the burner of step (c) or to another burner operated under conditions sufficient to convert substantially all of the sulfur and hydrogen sulfide in the fourth vapor phase product to a second combustion product comprising sulfur oxides; and(j) passing the second combustion product of step (i) into said first reactor under conditions sufficient to combine said sulfur oxides from step (e) with desulfated solid oxide in the first reactor, thereby producing a sulfated solid oxide and a treated vapor stream comprising less than about 50 ppm of sulfur oxides.