TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The solid transesterification catalyst is a double metal cyanide catalyst of formula ((M)2(M1)13(CN)10), preferably iron (II) zinc (III) deca cyanate, cobalt (II) zinc (III) deca cyanate or nickel (II) zinc (III) deca cyanate. The solid, acidic, etherification catalyst in the second reactor is zeolite beta, zeolite Y, or an acidic, polymeric cation exchange resin, preferably Amberlyst-15 (RTM: Ion exchange resin) or an aluminosilicate zeolite.M, M1 = metals having oxidation states of 2 or 3, preferably iron, cobalt, zinc or nickel.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The process further comprises: removing alcohol present in the effluents of the second reactor zone; and recycling the removed alcohol back to the transesterification reaction. The molar ratio of alcohol to triglyceride in the oil in the feed to the first reactor zone is greater than 6. In the process, when free fatty acids are present in the oil being transesterified, the free fatty acids are converted to alkyl esters of fatty acids over the transesterification catalyst. The temperature of the reaction in the first reactor zone is 60-200degreesC. The pressure in the first reactor is kept at the autogenous pressure of the alcohol at the transesterification reaction temperature. The temperature of the reaction in the second reactor zone is 120-200degreesC. The pressure in the second reactor zone is kept at the autogenous pressure of the alcohol at the etherification reaction temperature. The process is carried out in a reactor configuration such as two continuous stirred tank reactors connected in series, two fixed bed, plug flow reactors connected in series, continuous stirred tank first reactor connected in series with a fixed bed, plug flow second reactor, or a fixed bed, plug flow first reactor connected in series with a continuous stirred tank second reactor. The process is run via a cascade operation without separation or purification of the effluents from the first reactor zone. The alkyl esters of fatty acids are removed from the effluents from the first reactor zone. The separated alkyl esters are mixed with the glyceryl ethers from the effluents of the second reactor zone. Preferred Components: The oil is: a vegetable oil such as soyabean oil, rapeseed oil, corn oil, sunflower oil, cottonseed oil, jojoba oil, palm oil, olive oil, coconut oil, margarine oil and/or rubberseed oil; or a used oil such as corn oil, soyabean oil, sunflower oil, rubberseed oil, palm oil, rapeseed oil, linseed oil, peanut oil, canola oil, cotton seed oil, tallow, lard and/or yellow grease. The alcohol in the first reactor zone is a 1-10C alcohol, preferably methanol or ethanol. EXAMPLE - Hexa cyano potassium ferrate (II) (0.02 moles) was dissolved in a mixture of water (80 ml). Zinc chloride (0.2 moles) was dissolved in a mixture of water (200 ml) and tertiary butanol (40 ml). Triblock, poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol), of molecular weights 5800 (30 g) was dissolved in a mixture of tertiary butyl alcohol (80 ml) and water (4 ml). The zinc-containing solution was added to the iorn-containing solution over a period of 60 minutes at 50degreesC with vigorous stirring. The polymer solution was then added over a period of 5 minutes. Stirring was continued for a further 12 hours, filtered, washed with distilled water, and dried in air at 25degreesC for 2 days. The material was heated in air at 180degreesC for 4 hours to give a iron (II) zinc (III) deca cyanate. Sunflower oil (5 g) and ethanol (ethanol to oil molar ratio of 10:1) were preheated to 150degreesC and passed through a first reactor zone consisting of iron (II) zinc (III) deca cyanate (1 g). The catalyst was maintained at 170degreesC. The pressure in the first reactor was maintained at 10 bar. The effluents from the first reactor, consisting mainly of glycerol, ethyl esters of fatty acids and unreacted ethanol were cooled to 90degreesC and passed through a second reactor zone containing an Amberlyst-15 (RTM: Ion exchange resin) (1 g). The polymeric cation exchange resin was maintained at 90degreesC. The pressure in the second reactor was maintained at 1 bar. The effluents from the second reactor, containing ethyl esters of fatty acids, glycerol triethyl ether, and unreacted alcohol, were cooled. The unreacted alcohol was removed from the product by flash distillation to give the biodiesel (containing mixture of ethyl esters of the fatty acids and glycerol triethyl ether).