TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The catalyst of step (b) is selected from the compounds of cobalt (preferably cobalt acetate, cobalt chloride or cobalt sulfate). The catalyst of step (a) belongs to the compounds of tungsten and molybdenum, particularly their acids and alkaline salts. Catalyst tungsten and molybdenum (up to 2 mol%), and their acids and alkaline salts, is added to catalyst of the group of the compounds of cobalt.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: Production (M1) of saturated carboxylic acids and their derivatives involves: a) reacting unsaturated fatty acid derivative with an oxidizing compound in a catalyst (0.03 - 2, preferably 0.07 - 1.8, especially 0.08 - 1.5 wt.%) capable of catalyzing the double olefinic bond of unsaturated fatty acid derivative to give intermediate product vicinal diol; and b) reacting the intermediate compound with oxygen, or a compound containing oxygen, in a catalyst (0.1 - 3, preferably 0.2 - 2, especially 0.3 - 1.5 mol%) capable of catalysing the hydroxyl groups of the vicinal diol to carboxylic groups. The oxidizing compound is present in aqueous solution in a concentration of 30 - 70 (preferably 35 - 60, especially 40 - 49.9)%. In step (a), the water present in the reaction mixture and the catalyst dissolved are removed. An aqueous solution of the catalysts is added at the start of step (b), and the only water added is the water of the solution in which the catalyst is dissolved. At the start of step (a), the intermediate that is to be formed at the end of step (a) is added in less than 5 wt.%. The intermediate is added in less than 3 wt.%. The steps (a) and (b) are carried out at a pressure of less than or equal to 20 (preferably less than or equal to15, especially less than or equal to10) atm or at atmospheric pressure.Preferred Components: The oxidizing compound is hydrogen peroxide. Derivative of unsaturated fatty acid is a derivative of a mono -unsaturated fatty acid obtained by esterification of mixtures comprising the ones present in vegetable oils (preferably soybean oil, olive oil, castor oil, sunflower oil, peanut oil, rape-seed oil, corn oil or palm oil) (preferably 9-tetradecenoic acid (myristoleic acid), 9-hexadecenoic acid (palmitoleic acid), 9-octadecenoic acid (oleic acid), 12-hydroxy-9-octadecenoic acid (ricinoleic acid), icosenoic acid (gadoleic acid), 13-docosenoic acid (erucic acid) or 15-tetracosenoic acid (nervonic acid)). The carboxylic group of derivative of unsaturated fatty acid is modified by reaction with an alcohol to form an ester (preferably 1-9C alkyl group, especially methyl, ethyl or propyl). The modified unsaturated fatty acid is methyl oleate obtained by transesterification of methanol with the triglycerides contained in sunflower oil with a high content of oleic acid.Preferred Oil: The clear oil comprises the monomethyl ester of azelaic acid, pelargonic acid, and at least one ester of the methyl ester of dihydroxystearic acid with monomethyl azelate and/or pelargonic acid. EXAMPLE - Crude methyl oleate (methyl esters from sunflower oil with an extremely high content of oleic acid containing 92% methyl oleate; 1% methyl linoleate; 4% methyl palmitate; 3% methyl stearate) (1000 g), tungstic acid (10 g) crude methyl dihydroxy stearate (the intermediate obtained at the end of step (a) coming from a preceding reaction) (50 g) were heated at 65degreesC with hydrogen peroxide (H2O2) solution (49.9%, 250 cc) for 3 hours. Nitrogen was made to flow to distil a part of the water produced in the process. Water (70 cc) was distilled for 3 hours. Once addition of H2O2 had been completed, sodium bicarbonate (7 g) was dissolved in water (100 cc) to convert tungstic acid into tungstate, and the aqueous phase was separated when hot (at 60degreesC) from the organic phase. The aqueous solution containing the catalyst was separated, and oily phase (1150-1200 g) was obtained. The oily phase contained methyl dihydroxystearate (75-80%), palmitate and stearate, methyl-9,10-epoxystearate that is an intermediate of reaction, pelargonic acid and monomethyl azelate and acetal. Oily phase (1150 g) and disodium tungstate (15.1 g) were dissolved in water (200 cc). Cobalt acetate (6.9 g) was dissolved in water (100 cc). The two solutions were mixed, with precipitation of cobalt hydroxide. Cobalt(II) was then oxidized to cobalt(III) by of addition of a H2O2. The product was acidified to with hydrochloric acid to give pH of 3. The product was finally brought up to volume with 400 cc of distilled water. The temperature was raised to 75 - 80degreesC, and oxygen was bubbled through, at a rate of 30 lt/h. The reaction was carried out for 5 - 6 hour. Start of oxidation was detected by the change of colour of the catalytic solution from green to yellow. At the end of the reaction, the aqueous phase containing the catalyst was separated when hot. The oily phase (slightly more than 1150 g) comprised of pelargonic acid, monomethyl azelate, azelaic acid and dihydroxymethylstearic acid, methyl palmitate, methyl stearate, and mixtures of monoesters and di-esters of methyl dihydroxystearate with pelargonic and monomethyl azelate. The oily phase was treated with sodium carbonate or ammonia to transform the monomethyl azelaic acid and pelargonic acid into the corresponding water-soluble salts of sodium or ammonium. The two salts were separated out from the residue by addition of water to give mixture of acids. Distillation of the mixture of the acids gave pelargonic acid (350 g), and monomethyl azelate (450 g).