GB709653A - Improvements in and relating to fuel oils and the combustion of fuel oils - Google Patents

Abstract

A fuel oil composition, whose combustion products cause no oxidation, incrustation or corrosion of metallic surfaces with which they come into contact, comprises a high ash residual fuel oil and a minor proportion of red phosphorus or a metal- and sulphur-free organic or inorganic compound of phosphorus (other than an oil-soluble organic compound of phosphorus). The use of pyrophosphoric acid or mixtures of red phosphorus and sulphur in residual fuel oils is disclaimed. The high ash residual fuel oil is defined as a liquid fuel having an ash content of at least 0.005 per cent. by weight, when measured by method I.P. 4/44 of the Institute of Petroleum, and a viscosity of at least 100 seconds Redwood I at 100 DEG C. and consisting of or containing a residual petroleum oil. The high ash residual fuel oil may contain liquid fuels other than residual petroleum oils, such as distilled or cracked hydrocarbon fuel oils, while the residual petroleum oil may be one which yields, on combustion, an ash containing a major proportion of vanadium and/or sodium compounds. Inorganic phosphorus compounds mentioned are the oxides and oxy acids of phosphorus, such as phosphorus pentoxide, hypophosphorous acid, phosphorous acid, hypophosphoric acid, the phosphoric acids (other than pyrophosphoric acid) and the perphosphoric acids; the metal-free salts of oxy acids of phosphorus, such as the ammonium salts of the oxy acids listed above; and the hydrides and halides of phosphorus, such as di- and tri-hydrogen phosphide, phosphorus tri- or penta-chloride, phosphorus oxychloride and phosphonium chloride. Organic phosphorus compounds mentioned are the lower alkylphosphoric acid, phosphorous acid, di- or tri-alkylphosphine oxides and the organic base salts of the oxy acids listed above. Preferred phosphorus compounds are ortho- or meta-phosphoric acid, phosphorus acid, di- or triammonium orthophosphate, ammonium phosphite and ammonium pentametaphosphate. The red phosphorus or phosphorus compound may be added to the high ash residual fuel oil in bulk to form a solution, dispersion or emulsion, or it may be injected, either as such or as a solution, emulsion or suspension in a suitable liquid medium, such as water or an organic liquid, into the fuel oil supply lines. The injection may be continuous or intermittent, while a convenient way of adding the red phosphorus or phosphorus compound is in the form of a solution, emulsion or dispersion in a proportion of the high ash residual fuel oil which is to be burnt. In the examples, an aqueous solution of orthophosphoric acid or of triammonium orthophosphate, or red phosphorus, are added to petroleum residual fuel oil. According to the Provisional Specification, white phosphorus and other allotropic forms of phosphorus, pyrophosphoric acid, and sulphides of phosphorus such as phosphorus pentasulphide, may be employed.