Method for reconditioning bacteria-contaminated hydrogen sulfide removing systems

A method for reconditioning a system for treating a hydrogen sulfide-containing gas so as to convert said hydrogen sulfide to elemental sulfur, said system employing an aqueous, alkaline washing solution containing a water-soluble anthraquinone disulfonic acid and a water-soluble vanadate, said solution being contacted with an oxidizing agent to cause formation of said elemental sulfur and to regenerate said vanadate so said solution can be reused, said system including means for removing said elemental sulfur from said solution after said system and said solution have become contaminated with living, sulfur-feeding bacteria to an extent inhibiting said regeneration of said vanadate and operation of said sulfur removing means, said reconditioning method comprising the steps of:

• (a) adding to said washing solution a bactericidal agent selected from the group consisting of water-soluble phenols, the water-soluble salts and hydrates of phenols and the mixtures thereof in an amount sufficient to destroy substantially all of said sulfur-feeding bacteria;
• and
• (b) adding to said washing solution a surfactant selected from the group consisting of:
• (1) a polyoxyethylene condensate represented by the following general formula:
• R--O--(CH.sub.2 --CH.sub.2 --O).sub.n --H,
• wherein R is the residue of a fatty alcohol, acid, amide or amine having from about 10 to about 18 carbon atoms or an alkyl phenol having from about 10 to about 18 carbon atoms and where n is an integer of 1 or above;
• (2) a compound represented by the following general formula:
• ##STR6## wherein a, b, and c are integers between about 1 and about 100;
• and (3) an ethylene oxide adduct of acetylenic glycols represented by the general formula:
• ##STR7## wherein R.sub.1 and R.sub.4 are alkyl radicals containing from about 3 to about 10 carbon atoms, R.sub.2 and R.sub.3 are methyl or ethyl and x and y are integers having a sum in the range of about 3 to about 60, so as to remove at least a sufficient number of said destroyed bacteria from surfaces of said sulfur particles to enable said sulfur particles to agglomerate in said sulfur removal means.

A method for reconditioning a system for treating a hydrogen sulfide containing gas so as to convert said hydrogen sulfide to elemental sulfur, said system employing an aqueous, alkaline washing solution containing a water-soluble vanadate and water-soluble anthraquinone disulfonic acid, said solution being contacted with an oxidizing agent to cause formation of said elemental sulfur and to regenerate said vanadate so said solution can be reused, said system including autoclave means for removing agglomerated, elemental sulfur particles from said washing solution after said system has become contaminated with sulfur-feeding bacteria to an extent that agglomeration in said autoclave means of said particles into larger, easily removed sulfur particles is substantially inhibited, said reconditioning method comprising the steps of:

• (a) initially adding to said washing solution upstream of said autoclave means a bactericidal agent selected from the group consisting of water-soluble phenols, the water-soluble salts and hydrates thereof, and the mixtures thereof in an amount selected to destroy substantially all of said sulfur-feeding bacteria in said system;
• (b) adding to said washing solution upstream of said autoclave means a non-ionic surfactant selected from the group consisting of
• (1) a polyoxyethylene condensate represented by the following general formula:
• R--O--(CH.sub.2 --CH.sub.2 --O).sub.n --H,
• wherein R is the residue of a fatty alcohol, acid, amide or amine having from about 10 to about 18 carbon atoms or an alkyl phenol having from about 10 to about 18 carbon atoms and where n is an integer of 1 or above;
• (2) a compound represented by the following general formula:
• ##STR8## wherein a, b, and c are integers between about 1 and about 100;
• (3) an ethylene oxide adduct of acetylenic glycols represented by the general formula:
• ##STR9## wherein R.sub.1 and R.sub.4 are alkyl radicals containing from about 3 to about 10 carbon atoms, R.sub.2 and R.sub.3 are methyl or ethyl and x and y are integers having a sum in the range of about 3 to about 60, to remove sufficient dead bacteria from sulfur particles in said autoclave means to enable said sulfur particles to agglomerate;
• and
• (c) thereafter adding to said washing solution additional quantities of said bactericidal agent in an amount selected to maintain said system substantially free of bacterial contamination.