Patent ID: 7682460

Claim:
A method for cleaning apparatus(es) of a chemical or hydrocarbon processing plant to remove heavy organic compounds, foulants, sludge or coke, as material to be removed, comprising: a) connection of the apparatus(es) to be cleaned to a plant comprised of: heating means, a system for circulating a fluid, a connection system for establishing a closed loop, inlet/outlet for fluids, control means, filtering means; b) establishment of a closed flow circulation loop which effectively includes: the apparatus(es) to be cleaned, the heating means, the system for circulating a fluid, the connection system for establishing a closed loop, the inlet/outlet for fluids, the control means, the filtering means; c) filling of the apparatus(es) with a sufficient amount of hydrocarbon-based fluid(s), in a way that the closed flow circulation loop be full during subsequent circulation, and such that said closed flow circulation loop is full of said hydrocarbon-based fluid(s); d) circulation through the loop of the hydrocarbon-based fluid(s); e) heat up the circulating hydrocarbon-based fluid(s) to a temperature comprised between 100° C. and 600° C.; f) set up the pressure of the circulating hydrocarbon-based fluid(s) to a value comprised between 1 bar and 50 bar; g) circulation of the hydrocarbon-based fluid(s) for a time sufficient to clean the apparatus(es) of the material to be removed, comprised of between 20 minutes and 7 days, at temperature comprised between 100° C. and 600° C. and a pressure comprised between 1 bar and 50 bar, with the pressure and temperature being effective in solubilizing the material to be removed; h) monitoring of the status of cleaning operations, as to determine cleaning time, by performing chemical and/or physical analysis; i) removal of the circulated hydrocarbon-based fluid(s).