The present invention relates to the production of biodiesel and alkyl esters by the transesterification of triglyceride esters, with alcohols in heterogeneous phase in the presence of heterogeneous catalysts, with yields higher than 80%, at a temperature from 0 to 300° C., residence time from 20 minutes to 20 h, space velocity of 0.1 to 10 h.sup.−1, pressure of 25-100 kg/cm.sup.2 (24.5-98.07 bar), methanol/oil molar ratio of 10 to 40 and catalyst concentration of 0.001 to 20 weight % based on tri-, di- or monoglyceride. The method produces biodiesel and alkyl esters by transesterification of tri-, di- or mono-glycerides, from palm, jatropha, castor, soybean and sunflower oils, wherein the alcohoxyls R.sup.1O, R.sup.2O and R.sup.3O of the glycerides are C.sub.1 to C.sub.24 and a C.sub.1-C.sub.4 alcohol, such as methanol, in an alcohol:oil ratio from 3:1 to 50:1. The transesterification reaction produces biodiesel while avoiding loss of catalyst, contaminating liquid effluents and eliminating undesirable hydrolysis of triglycerides, diglycerides and monoglycerides into free fatty acids and saponification that generate soaps.

A diesel fuel composition containing a renewable diesel component and oxymethylene ethers having molecular structure CH3O—(CH2O)n-CH3 with n=3-5 (OME3-5). A method for producing a diesel fuel composition and use thereof. Use of OME3-5 to decrease particle emission of renewable diesel fuels is further disclosed.

A motor fuel comprising gasoline comprising 70-99 wt % gasoline and 1 to 30 wt % of mesitylene. This fuel can advantageously contain conventional additives used in gasoline. The use of mesitylene in gasoline blend yields a fuel blend with a higher research octane number and motor octane number. In addition, an improved jet fuel is provided, having from 1-10 wt % mesitylene added to the jet fuel, having improved carbon emission characteristics while maintaining required specifications. Further, an improved bio-fuel is provided, which may function as a replacement for conventional Jet A/JP-8 fuel and has lowered carbon emission specifications, the bio-fuel comprised of 75-90 wt % synthetic parafinnic kerosene (SPK) and 10-25 wt % mesitylene.

The disclosure encompassed herein relates, in part, to a method for increasing energy density of plant biomass that can be used for production of renewable fuel, such as biodiesel oil and/or ethanol. In an aspect, genetic engineering for enhanced sugar accumulation can be achieved by overexpressing a bacterial enzyme sucrose isomerase. Sugars or oils extracted from the plants of the disclosure encompassed herein may be used for industrial purposes such as heating, producing bio-fuels such as biodiesel fuel, or lubricating applications.

A method for production of a biodiesel is described herein. The method for production of a biodiesel comprises (a) separating solids from a waste oil composition to provide a clarified oil composition; (b) acidifying the clarified oil composition to produce an acidified oil composition including free fatty acids derived from the waste oil; (c) converting at least a portion of the free fatty acids in the acidified oil composition to glycerides to provide a glyceride composition; and (d) reacting at least a portion of the glycerides in the glyceride composition with methanol to form fatty acid methyl ester to provide a biodiesel composition.

A fuel composition for use in internal-combustion engines has a fuel component, an alcohol component, a water component, a microemulsion blend, and a cetane-enhancer component. The microemulsion blend includes at least one of lower grade fatty acid derivatives being present in an amount effective for the fuel, alcohol, and water components to form a microemulsion blend. The emulsifier is present in an amount effective for the biodiesel fuel, alcohol, water, and emulsifier to form an emulsion.

There is described a process and an apparatus for purifying a mixture and related products. In particular, there is described a process and an apparatus for purifying a mixture comprising fats, oils and greases as are typically found in sewer waste. The process involves heating, acidifying and separating the mixture. The apparatus used includes a heating and separation device for separating into a solid fraction, an organic liquid fraction and an aqueous liquid fraction. Apparatus such as a three phase separation unit and a rotary vacuum filter may also be used.

A process for production of biofuels from algae can include cultivating an oil-producing algae by promoting sequential photoautotrophic and heterotrophic growth. The method can further include producing oil by heterotrophic growth of algae wherein the heterotrophic algae growth is achieved by introducing a sugar feed to the oil-producing algae. An algal oil can be extracted from the oil-producing algae, and can be converted to form biodiesel.

The invention discloses a method for producing bio-fuel (BF) from a high-viscosity biomass using thermo-chemical conversion of the biomass in a production line (10) with pumping means (PM), heating means (HM) and cooling means (CM). The method has the steps of 1) operating the pumping means, the heating means and the cooling means so that the production line is under supercritical fluid conditions (SCF) to induce biomass conversion in a conversion zone (CZ) within the production line, and 2) operating the pumping means so that at least part of the production line is in an oscillatory flow (OF) mode. The invention is advantageous for providing an improved method for producing biofuel from a high-viscosity biomass. This is performed by an advantageous combination of two operating modes: supercritical fluid (SCF) conditions and oscillatory flow (OF).

The present invention provides a method for producing a biofuel that allows an animal/vegetable fat/oil raw material containing a free fatty acid to react with a lower alcohol in the presence of a solid acid catalyst, in which the consumption of the lower alcohol is reduced and the free fatty acid and the lower alcohol are selectively esterified to reform the animal/vegetable fat/oil. In this method, as a solid acid catalyst is used a catalyst selected from an SiO.sub.2/Al.sub.2O.sub.3 solid acid catalyst, an SiO.sub.2/Al.sub.2O.sub.3 solid acid catalyst with aluminum being partially introduced into mesoporous silica, an Al.sub.2O.sub.3/B.sub.2O.sub.3 solid acid catalyst, and a sulfated zirconia solid acid catalyst, with a molar ratio of the free fatty acid and the lower alcohol of 1 to 6.