Abstract: A composition for recovering and upgrading sludge that accumulates in vessels for storing and transporting petroleum products comprises a solvent made up of at least one aliphatic hydrocarbon and at least one aromatic monohalogenated hydrocarbon of the benzene or naphthalene type, together with a demulsifying and dispersing agent that is an aliphatic straight-chain oxyethylated amineated derivative or a quaternary ammonium compound having at least one alkyl and at least one aryl residue in the form of thiocyano derivative.The composition is dissolved in a hydrocarbon in a proportion of from 2 to 10% by weight, the resulting solution is projected on to the residues at a pressure of from 2 to 15 bars, and the resulting suspension is recycled, recovered, and treated like crude oil.The invention is applied to the recovery and upgrading of sludges which accumulate in storage vessels and petroleum product transport vessels, whether they are on the ground or on land or sea transport vessels.

Abstract: A process for cleaning surfaces of installations fouled by products of combustion of carbon-bearing materials, such as in particular boiler combustion chambers, rotary or static heat exchangers, combustion product ducts and flues, electrostatic filters, etc., which are to be cleaned without having to stop the combustion process, in order to maintain maximum thermal efficiency in order thereby to make a substantial energy saving, in which an aqueous solution of ammonium nitrate and potassium nitrate is injected into the installation, the deposited substances being detached from the installation by means of sound sources.