Elimination of SO
A process to treat/clean a gas, containing SO 2 , CO 2 and O 2 comprising the steps of: bringing the gas in contact with an activated carbon catalyst, converting SO 2 to SO 3 /H 2 SO 4 on the activated carbon catalyst, washing the SO 3 /H 2 SO 4 from the activated carbon catalyst to obtain a sulfuric acid solution and a SO 2 depleted gas; bringing the SO 2 depleted gas in contact with an aqueous ammonia solution wherein CO 2 is converted to obtain a SO 2 and CO 2 depleted gas containing ammonia; and bringing the SO 2 and CO 2 depleted gas containing ammonia in contact with the sulfuric acid solution obtained in step a. to form a solution containing ammonium sulfate and a treated, clean gas.
1. A process to treat or clean a gas containing SO 2 , CO 2 and O 2 , said process comprising the steps of:
(a) bringing the gas in contact with an activated carbon catalyst, converting SO 2 to SO 3 /H 2 SO 4 on the activated carbon catalyst, washing the SO 3 /H 2 SO 4 from the activated carbon catalyst to obtain a sulfuric acid solution and a SO 2 depleted gas;
(b) bringing the SO 2 depleted gas in contact with an aqueous ammonia solution wherein CO 2 is converted to obtain a SO 2 and CO 2 depleted gas containing ammonia;
(c) bringing the SO 2 and CO 2 depleted gas containing ammonia in contact with the sulfuric acid solution obtained in step (a) to form a solution containing ammonium sulfate and a treated, clean gas.
2. The process of claim 1 , wherein the activated carbon catalyst is a mixture of an activated carbon catalyst and a filler material.
3. The process of claim 2 , wherein the mixture contains no other solid ingredients than at least one of an activated carbon catalyst and a filler material.
4. The process of claim 2 , wherein the filler material is chosen from fillers made of at least one of ceramic material, metal, plastic material and mixtures thereof.
5. The process of claim 2 , wherein the filler material is a shape chosen among saddle shaped, ring shaped, ball shaped, torus shaped, prism shaped or irregular shaped.
6. The process of claim 2 , wherein the mixture of the activated carbon catalyst and the filler material is in a fixed bed.
7. The process of claim 1 , wherein the activated carbon catalyst is washed in step (a) with water or an aqueous solution in an amount between 5 l/hour/m 3 of activated carbon catalyst and 100 l/hour/m 3 of activated carbon catalyst.
8. The process of claim 1 , wherein the activated carbon catalyst is washed by intermittent spraying with at least one of water and an aqueous solution in counter-flow to the gas.
9. The process of claim 1 , wherein the gas containing CO 2 , SO 2 and O 2 is a natural gas, syngas, flue gas generated by at least one of:
combustion of carbon and hydrogen-containing fuels;
chemical processes; and
metallurgical processes.
10. The process of claim 1 , wherein the gas being brought into contact with the activated carbon catalyst has a temperature of between 10 and 150° C.
11. The process of claim 1 wherein the SO 2 content of the gas is between 50 and 5,000 ppm.
12. The process of claim 1 wherein the CO 2 content of the gas is between 2 and 20 v %.
13. The process of claim 1 , wherein the O 2 content of the gas is between 5 and 20% vol.
14. The process of claim 1 , wherein the H 2 SO 4 content of the H 2 SO 4 solution is between 5 and 50% vol.
15. The process of claim 1 , wherein the aqueous ammonia solution in step (b) comprises at least one of ammonia, urea and a mixture thereof.
16. The process of claim 1 , wherein steps (a) and (c) take place in a same reactor.
17. The process of claim 16 , wherein the reactor contains an upper bed of the activated carbon catalyst where step (a) takes place and a lower bed where step (c) takes place.