Patent ID: 6852683

Claim:
A detergent composition for non-aqueous washing of the inside of a petroleum refining apparatus, the composition comprising: a petroleum solvent comprising a light oil, a surfactant having a solubility of at least 10 with respect to a diesel fuel at a temperature of 25° C. and comprising at least one of petroleum sulfonate, lecithin, sorbitan esters having an HLB value of 1 to 10, aliphatic esters having an HLB value of 1 to 10, alkyl ether nonions having an HLB value of 1 to 10, and alkylaryl ether nonions, and a terpene compound, wherein the surfactant comprises 5 to 80% by weight of the mixture of the surfactant and the terpene compound, and 0.5 to 20% by weight of the mixture of the surfactant and the terpene compound is dissolved in the light oil.