METHOD OF PRODUCING ELEMENTARY SULFUR FROM HYDROGEN SULFIDE AND CYCLIC METHOD FOR PRODUCING HYDROGEN PEROXIDE Russian patent published in 1997 - IPC

FIELD: sulfur and hydrogen peroxide production. SUBSTANCE: hydrogen sulfide-containing gas is brought in contact with 2,3-dialkyl-substituted naphtoquinone in presence of amine catalyst dissolved in hydrophobic organic solvent system to produce corresponding quinhydrone and insoluble elementary sulfur. Total number of carbon atoms in alkyl substituents ranges advantageously from 2 to 6. Most appropriate compounds are dimethyl- and/or ethyl/methylnaphtoquinones. Preferable pH value is 9 to 11.5 and preferable solvent systems are mixtures of aromatic hydrocarbons with alifatic esters, such as methyl cyclohexanolacetate, or dialkylcarbinols, such as diisobutylcarbinol. Naphtoquinones react with H₂S substantially faster than antraquinone and tetrahydpoanthraquinone compounds which are known reagents with H₂O_r. Insoluble sulfur may be removed as reaction product, whereas solution containing reduced naphtoquinhydrone may be brought in contact with oxygen-containing gas to produce hydrogen peroxide and produce back naphtoquinone. Extracted with water to remove H₂S, solution may be reused in contact with another H₂S-containing gas. EFFECT: enhanced hydrogen sulfide conversion process. 16 cl