Two-stage gas washing method applying sulfide precipitation and alkaline absorption
AssigneeNeste Oyj
InventorsJan Wahlström, Juhani Aittamaa, Isto Eilos, Kari I. Keskinen, Jukka Koskinen, Marja Tiitta, Heli Vuori
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Abstract
Disclosed is a method relating to hydrocarbon production by gasification of carbonaceous material, for example, a two-stage gas washing method as a part of gas refining. Disclosed is a method for hydrogen sulfide and carbon dioxide removal from synthesis gas produced by gasification. Disclosed is a use of a combination of two chemical wash approaches. The process can be utilized as a part of biomass to liquid (BTL) process.
Claims24
A method for washing hydrogen sulfide and carbon dioxide from a gas obtainable by gasification of a carbonaceous biomass, the method comprising:
- a) contacting the gas with a first absorbent solution comprising transition metal ions in acidic aqueous solution, wherein the transition metal ions include copper, zinc, iron, cobalt or a mixture thereof;
- b) binding hydrogen sulfide present in the gas to said first absorbent solution;
- c) recovering the gas from step b);
- d) contacting the recovered gas from step c) with a second absorbent solution comprising an alkaline absorbent;
- e) binding carbon dioxide present in the recovered gas from step c) to said second absorbent solution;
- and
- f) recovering the gas obtained from step e).
Dependencies are inferred from the claim text.