WO2013006968A1 - Catalysts and methods for the production of biodiesel - Google Patents

Abstract

In an embodiment there is disclosed a method for the production of biodiesel. The method of the embodiment comprises the step of carrying out a transesterification reaction between biomass oil and alkanol, and the reaction occurs in the presence of a catalyst. In an embodiment the catalyst comprises a transition metal compound and an element selected from the group consisting of carbon, nitrogen, oxygen, sulphur, phosphorous and selenium. There are also disclosed catalysts and methods for making the catalysts. Catalysts according to selected embodiments comprise titanium dioxide and sulphur.

Description

CATALYSTS AND METHODS FOR THE PRODUCTION OF BIODIESEL

Field

The subject matter disclosed generally relates to catalysts and methods for the production of biodiesel.

Background

European Patent EP-B-0 198243, discloses a transesterification catalyst, which transforms oil and methanol into methyl ester and comprises alumina or a mixture of alumina and ferrous oxide.

UK patent GB-A-795573 describes using zinc silicate as a catalyst at temperature of between 250-280°C and under a pressure of at least 100 bar, with methanol. US Patent no. 4668439 describes a continuous production process in which operations are carried out at atmospheric pressure and where the ester and glycerin are evaporated by running excess through oil at more than 210°C, most often 240°C; in the presence of soluble catalyst.

References

M. Bilal Khan, AN Bahadar, Waqas Anjum, "Production of Biodiesel from Jatropha Curcas using Nano Materials". AIP Conf. Proc, September 1 4, 2009, Volume 1 169, pp. 197-205.

Vicente, G., Martinez, M., Aracil, J . /'Integrated biodiesel production: a comparison of different homogeneous catalyst systems". Bioresour. Technol. 2004; 92:297- 305.

Antolin, G., Tinaut, F., Briceno, Y., Castano, V., Perez, C, Ramirez, A., "Optimization of biodiesel production by sunflower oil transesterification". Bioresour. Technol. 2002; 83:1 1 1 -4.

Martini, N., Schell, S., "Plant oil as fuels: present state of future developments". In: Proceedings of the synopsis. Potsdam, Germany, Berlin: Springer; 1998. p.6. Lang, X., Dalai, A.K., Bakhash N., Reaney, M., Hertz, P., "Preparation and characterization of biodiesels from various bio-oils". Bioresour. Technol. 2001 ; 80:53-62.

Freedman, B., Butterfield, R., Pryde, E.H.. "Transesterification kinetics of soybean oil". J . Am. Oil Chem. Soc. 1986; 63:1375-80. Pramanik, K. /'Properties and use of Jatropha curcas oil and diesel fuel blends incompression ignition engine". Renew. Energ. 2003; 28:239-48.

Meher, L, Kulkarni, M., Dalai, A., Naik, S. /Transesterification of karanja {Pongamia pinnata) oil by solid catalysts". Eur. J. of Lipid Sci. Technol. 2006; 108:389-97.

Senthil, Kumar M., Ramesh, A., Nagalingam, B., "An experimental comparison of methods to use methanol and jatropha oil in a compression ignition engine". Biomass Bioenerg. 2003; 25:309-18.

Encinar, J.M., Gonzalez, J .F., Rodriquez, J. J ., Tejedor, A., Biodiesel production from vegetable oils: transesterification of Cynara cardunculus L. Oil ethanol. Energ. Fuel 2002; 16:443-50.

Agarwal, A.K., Das, L.M., "Biodiesel development and characterization for use as a fuel in compression ignition engines". Trans. Am . Soc. Mech. Eng. 2001 ; 123:440- 7. 1 . 6th ed. Germany: Pergamon; 1979.

"Optimization of biodiesel production from edible and non-edible vegetable oils" Prafulla D. Patil, Shuguang Deng, Chemical Engineering Department, New Mexico State University, P.O. Box 3001 , MSC 3805, Las Cruces, NM 88003, USA Fuel 88 (2009) 130201306.

"Jatropha curcas L. Cultivation Experience in Karachi Pakistan" by Syed Asim Rehan Kazmi, Mr. Abdul Hameed Solangi and Syed Nawaid Anjum Zaidi (PSO Library) .

Rao, P. S., and K. V. Gopalakrishnan, 1991 , "Vegetable oils and their methyl esters as fuels for diesel engines" Indian J. Technol. 29(6):292-297.

Arkoudeas, P., et al. 2003, "Study of using JP-8 aviation fuel and biodiesel in CI engines" Energy Conversion and Management, 44(7) :101 3-1025.

Lotero, E., et al. 2005, "Synthesis of biodiesel via acid catalysis" Ind. Eng. Chem. Res. 44:5353-5363.

Zhang, Y., et al. 2003, "Biodiesel production from waste cooking oil: 1 . Process design and technological assessment" Bioresour Technol. 89:1 -16.

Summary

There is disclosed a method for the production of biodiesel, the method comprising the step of carrying out a transesterification reaction between biomass oil and an alkanol, in the presence of a catalyst comprising: a transition metal compound selected from the group consisting of a carbide, oxide, nitride, sulphide, phosphide, and selenide; and an element selected from the group consisting of carbon, nitrogen, oxygen, sulphur, phosphorous and selenium. In a further embodiment there is disclosed a method for the production of biodiesel, the method comprising the step of carrying out a transesterification reaction between biomass oil and alkanol, in the presence of a catalyst comprising a transition metal oxide and an element selected from the group consisting of carbon, nitrogen, oxygen, sulphur, phosphorous and selenium. In a further alternative embodiment where the catalyst comprises a transition metal oxide the catalyst further comprises an element selected from the group consisting of Carbon, Oxygen, Nitrogen, Phosporous, Sulphur and Selenium.

In an alternative embodiment the transition metal oxide is Titanium dioxide and the element is sulphur.

In alternative embodiments the catalyst comprises particles having a diameter of between about 1 nm and about 500nm .

In alternative embodiments the reaction occurs over a residence time of between about 3 minutes and about 10 minutes.

In alternative embodiments the reaction occurs at a temperature of between about 15°C and about 25°C.

In alternative embodiments the biomass oil is derived from a plant source.

In alternative embodiments the plant source comprises one or more of Jatropha Curcas L and algae.

In alternative embodiments the alkanol comprises

a) methanol; or

b) ethanol; or

c) methanol and ethanol.

In alternative embodiments the reaction is carried out a biomass oil to alkanol ratio of about 1 :0.75 to 1 :1 .5 by weight.

In an alternative embodiment there is disclosed a catalyst for the transesterification of biomass oil and alkanol, the catalyst comprising a transition metal oxide and an element selected from the group consisting of Carbon, Oxygen, Nitrogen, Phosporous, Sulphur and Selenium . In a further alternative embodiment where the catalyst comprises a transition metal oxide the catalyst further comprises an element selected from the group consisting of Carbon, Oxygen, Nitrogen, Phosporous, Sulphur and Selenium.

In alternative embodiments the transition metal oxide is titanium dioxide and the element is sulphur.

In alternative embodiments the catalyst comprises particles between about 1 nm and about 500nm in diameter.

In further embodiment there is disclosed a method for making the catalyst according other embodiments, the method comprising the step of contacting the transition metal oxide with a solution of the element.

In alternative embodiments the method comprises the step of sintering the element treated transition metal oxide.

In an alternative embodiment there is disclosed a method for making a titanium dioxide-sulphur catalyst, the method comprising the step of reacting a sulphur containing compound with titanium (IV) isopropoxide.

In an alternative embodiment the method comprises the step of sintering the solid reaction product at a temperature of between about 400°C and about 500°C for between about 3 hours and about 5 hrs.

In a further embodiment there is disclosed biodiesel made using the methods according to embodiments.

In a further embodiment there is disclosed biodiesel made using the catalyst according to embodiments.

In a further embodiment there is disclosed biodiesel comprising less than about 5% impurities.

In a further embodiment there is disclosed biodiesel according to embodiments with a flash point of between about 120C-150°C and a cloud point of less than about 5°C below zero.

In embodiment the alkanol is an alcohol and may be methanol or ethanol.

Features and advantages of the subject matter hereof will become more apparent in light of the following detailed description of selected embodiments, as illustrated in the accompanying figures. As will be realized, the subject matter disclosed and claimed is capable of modifications in various respects, all without departing from the scope of the claims. Accordingly, the drawings and the description are to be regarded as illustrative in nature and not as restrictive and the full scope of the subject matter is set forth in the claims. Brief Description of the Drawings and Tables

FIG.1 . Is a flow diagram for biodiesel production according to an embodiment. FIG.2. Is an FTIR Comparison of biodiesel produced from algae, and Jatropha compared to petro-diesel.

FIG.3. Is a gas chromatograph of biodiesel produced from non-edible energy crop oil according to an embodiment.

Fig.4. Is a schematic drawing of a process for continuous production of biodiesel according to an embodiment.

FIG.5. Is an X-ray diffraction pattern of a sulphur treated titanium dioxide catalyst according to an embodiment.

Detailed Description of Embodiments

Terms

In this disclosure, the word "comprising" is used in a non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article "a" does not exclude the possibility that more than one of the elements is present, unless the context clearly requires that there be one and only one of the elements. It will also be understood that the statement that a combination or embodiment comprises one or more characteristics or components, envisages that in alternative embodiments the embodiment or combination may alternatively consist of, or consist essentially of, such characteristics or components.

In this disclosure the recitation of numerical ranges by endpoints includes all numbers subsumed within that range including all whole numbers, all integers and all fractional intermediates (e.g., 1 to 5 includes 1 , 1 .5, 2, 2.75, 3, 3.80, 4, and 5 etc.).

In this disclosure the singular forms "a", "an", and "the" include plural referents unless the content clearly dictates otherwise. Thus, for example, reference to a composition containing "a compound" includes a mixture of two or more compounds.

In this disclosure term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise.

In this disclosure, unless otherwise indicated, all numbers expressing quantities or ingredients, measurement of properties and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary or necessary in light of the context, the numerical parameters set forth in the disclosure are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings of the present disclosure and in light of the inaccuracies of measurement and quantification. Without limiting the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the disclosure are approximations, their numerical values set forth in the specific examples are understood broadly only to the extent that this is consistent with the validity of the disclosure and the distinction between the subject matter disclosed and claimed and the subject matter disclosed in the prior art.

In this disclosure the terms "agitator", "agitate", "mixer", "mix" and the like, unless the context dictates otherwise, indicate the intermingling or mixing of one or more liquids and/or particulate matter or apparatus for achieving such mixing or intermingling. In embodiments this refers to the mixing of alkanol, such as an alcohol with oil and catalyst. In embodiments such mixing may be gentle or vigorous or violent, and may be achieved using any suitable means, a wide variety of which will be readily identified and implemented by those skilled in the art. By way of example and not limitation, in embodiments liquids are agitated by recirculating or shaking, or by means of rotating or oscillating paddles, vanes, stirrer bars, plungers, or by sound, or by ultrasound, or by convection. In particular embodiments, liquids may be mixed or agitated using a heated or magnetic platform and stirrer.

In this disclosure the term "pump" has its ordinary meaning and should be understood in its broadest sense and is not limiting. By way of example and not limitation a pump may be any means of raising, moving or transferring fluids and may be driven by or comprise a piston, impeller or peristaltic device and may be a positive displacement pump, a piston pump, vacuum pump, a peristaltic pump or any other pump or equivalent, a wide variety of which will be readily apparent to those skilled in the art. In this disclosure the term "valve" has its ordinary meaning and encompasses all means for controlling the flow of a liquid or gas through an opening, and those skilled in the art will readily identify and implement a variety of valve types and designs suitable for use in embodiments. By way of example and not limitation, valves may be of any suitable type and in particular embodiments are ball valves, brass valves, clip valves, butterfly valves, plate and vane valves, electronic valves, gate valves, magnetic valves, taps, or any other means for controllability preventing, or permitting flow of fluids, liquids or gases through a conduit, pipe, tube or opening. It will be understood that in circulation loops and for other selected applications valves may be of a non-return or one-way design. In particular embodiments, valves are controlled by any suitable means and where desired may be equipped with suitable diaphragms to prevent overpressure damage.

In this disclosure the term "filter" refers to any conventional mechanism for removing particulate matter from a liquid or gas. In particular embodiments filters are paper or nylon or plastic or metal or are fuel filters or any other suitable filter types. In particular embodiments, filters are used in series or in any desirable form or arrangement, all of which will be readily understood by those skilled in the art. In some embodiments, filters have a mesh size of about 300 microns but it will be understood that a wide range of mesh sizes may be suitable in particular applications and smaller or larger mesh sizes will be selected from and adopted by a user. In alternative embodiments the removal of finer particulate matter is achieved using smaller mesh filters, for example 250micron, 200 micron, 150 micron, 100 micron or smaller, or the equivalent removal of particulates may be achieved using centrifugation or other suitable means.

In this disclosure the term "biomass" is understood to include all forms of material derived from living organisms and includes but is not limited to plant, animal, algal and bacterial matter. In particular embodiments biomass means plant matter. In this disclosure the term "biodiesel" means a chemical composition primarily composed of the esters, including but not limited to alkyl esters, including but not limited to methyl esters, of lipids. In embodiments these comprise or are comprised in vegetable oils or fats, or animal oils or fats, or both plant and animal oils and fats. In particular embodiments the esters are or comprise, monoalkyl esters, and in embodiments these consist of or comprise methyl, ethyl, and propyl esters or one or more of the foregoing. In particular embodiments "biodiesel" or "biogasoline" means a fuel which is entirely biologically derived and contains no added petro-diesel, and comprises mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats. Such a composition is commonly designated B100 and indicates that 100% of the fuel mix is biodiesel. Biodiesel manufactured according to embodiments has the characteristics, such as viscosity and flashpoint, necessary to satisfy the requirements of ASTM INTERNATIONAL™ standard D 6751 or similar European standard EN 1421 . It will be understood that biodiesel according to embodiments can be used to drive unmodified diesel engines. In embodiments biodiesel is made through a chemical process of transesterification.

In this disclosure the term "transesterification" means a process whereby a lipid, fat, triglyceride, fatty acid or oil is reacted with an alkanol to separate out the glycerin contained therein. The transesterification process generates two products, namely: bio-diesel and glycerin. In particular embodiments the glycerin is suitable for commercialisation such as use in soaps and other products. In particular embodiments a lipid, oil, triglyceride or fatty acid is treated to neutralize the free fatty acids, and the glycerin is thereafter removed leaving an alkanol ester. In embodiments the alkanol is an alcohol and in embodiments is or comprises methanol or ethanol or methanol and ethanol.

In this disclosure the term "biomass oil" means oil derived directly or indirectly from biomass. In embodiments the biomass is or comprises a plant material or plant source or is or comprises algal material or algal culture or is or comprises or is derived from bacterial material or bacterial cultures or is or comprises animal matter or any other form of biomass. In embodiments fats are heated or otherwise converted to a liquid or oil phase which is then converted to biodiesel using the embodiments of compositions, methods and apparatuses disclosed herein.

In this disclosure "pipes", "tubes", "conduits" and the like may be of any desired dimensions and materials. In particular embodiments, piping has inlet diameters of about 10 to 20mm and outlet diameters of up to about 50mm or more. In particular embodiments, piping is made of stainless steel.

Those skilled in the art will recognize that a range of alternative materials and dimensions may be selected and adapted to suit particular requirements. The selected materials and dimensions will be compatible with the materials they are in contact with and suitable to the volumes and conditions with which they must function. A wide range of materials will be recognized and implemented by those skilled in the art.

In this disclosure a "centrifuge" may be of any suitable type. In embodiments a centrifuge is an ultracentrifuge and in alternative embodiments is a centrifuge that operates at lower speeds, the selection being dependent on the requirements of the user. In an embodiment of a batch centrifuge, the centrifuge holds about 500ml per ampoule but in alternative embodiments larger and smaller capacities may be adopted as desired. Where a continuous operation centrifuge is to be used, a capacity of up to or greater than about 10 litres/minute is contemplated, and centrifugation speeds of up to or greater than about 10,000 RPM are considered to be suitable. Those skilled in the art will readily identify and implement suitable centrifuge designs to carry out the desired steps and functions in embodiments.

In this disclosure the term "plant source" refers to all manner of agricultural and algal plant material. In variant embodiments a plant source is or comprises whole plants, including angiosperms, gymnosperms, monocotyledonous and dicotyledonous plants, lower plants, algae and all manner of photosynthetic organisms, and in further variant embodiments includes parts of plants, seeds, beans, fruits, or cultures of plant material or plant cells, or includes leaves, stems, roots, fruits and other forms of plant tissue or includes combinations, fragments, or components of any of the foregoing or includes tissues or cultures of one or more algal species. In embodiments a plant source or plant material comprises refined or purified or enriched components such as lipids, fats or oils or comprises waste plant oils. In embodiments a plant source, comprises waste cooking oils or edible oils. In embodiments plant sources or plant materials are pretreated, compressed, processed, heated, cooled, preserved, frozen, chopped, ground, fragmented, pulverized, solubilized, comminuted, shredded or permeabilised or otherwise treated to facilitate subsequent processing. In embodiments plant sources comprise plant materials, including plant oils, derived from any suitable species or variety, and by way of example but not of limitation in variant embodiments such species or varieties include canola, castor, soy, rape, palm, or algal species or varieties, and in certain variant embodiments comprise Euphorbiaceae species or varieties, Jatropha species or varieties and in embodiments comprise Jatropha Curcas L. In particular embodiments and without limitation, a plant source comprises one or more of castor oil, castor bean oil, soy oil, soybean oil, jatropha oil or jatropha seed oil. In embodiments, and without limitation, where plant sources comprise algal material then in embodiments such algal material comprises or consists of or is derived from one or more of Botryococcus braunii; Chlorella; Dunaliella tertiolecta; Gracilaria; Pleurochrysis carterae (which may also be referred to as CCMP647); Sargassum; Gracilaria; Ulva or related strains or may comprise or consist of or be derived from one or more of Ankistrodesmus, Chlorella protothecoides, Cyclotella, Haritzschai DI- 160, Nannochloris, Nannochloropsis, Nitzschia TR114, Phaeodactylum tricornutum, Scenedesmus, Stichococcus, Tetraselmis suecica, Thalassiosira pseudonana, Crpthecodinium cohnii, Neochloris oleoabundans and Schiochytrium. For simplicity of explanation, "plant material" and "plant source" are understood to include all manner of plant, algal and bacterial matter.

In particular embodiments a plant source comprises the oil extracted from Jatropha Curcas and in embodiments using Jatropha Curcas a biodiesel yield of up to 2800kg oil/Hectare is achievable.

In this disclosure the term "alkanol" means any organic compound containing a hydroxyl (— OH) functional group, other than those wherein the hydroxyl group is attached to an aromatic ring. In particular variant embodiments alkanols are monohydric, dihydric, trihydric, or polyhydric and in variant embodiments are straight or branched chain and in embodiments bear any substituent groups that are compatible with the transesterification reactions contemplated in this disclosure. All of such modifications and variants will be readily identified by those skilled in the art who will similarly readily understand which variants and substituent groups should be avoided.

In this disclosure the term "alcohol" refers to all alcohols whose chemical properties are compatible with the processes and catalysts according to embodiments. In particular embodiments an alcohol is or comprises ethanol, methanol, or a mixture of ethanol and methanol. However, those skilled in the art will readily understand that in particular embodiments, other forms of alkyl, aliphatic, alicyclic, straight chain, branched chain, saturated and unsaturated, and mixed alcohols are useable. Without in any way limiting the range of possible alcohols, in particular embodiments suitable alcohols comprise one, two, three, four, five and six carbon alcohols, and comprise any alcohols that comprise 1 , 2, 3, 4, 5, 6, 7, 8, or more hydroxyl groups, and in alternative embodiments comprise any substituted forms and isomers of any of the foregoing. In particular embodiments and without limitation, the following types of alcohol are or may be suitable: methanol, ethanol, ethane-1 ,2-diol, 1 -propanol, 2-propanol, 1 ,3- propanediol, propan-1 ,2,3-triol, 2-methyl-2-propanol, 1 -butanol, isobutanol, 2- butanol, 2,3-butanediol, 1 ,4-butanediol, 2,3-butandiol; 2-methyl-2-butanol, 3- methylbutanol, 1 -pentanol, 2-pentanol, 3-pentanol, 2,3-pentanediol, 1 ,5- pentanediol, 1 ,2-cyclopentanediol, cyclopentanol; 4-methylpentanol, 4-methyl-2- pentanol, 2-methyl-3-pentanol, 4-methyl-2,3-pentanediol, 1 -hexanol, 2-hexanol, 3- hexanol, 2,3-hexanediol, 3,4-hexanediol and cyclohexanol. Those skilled in the art will readily adjust the conditions and reaction parameters of embodiments to favour or optimise the production of particular desired alcohols. It will understood that all forms of alcohol are included within the term "alkanol" and those skilled in the art will readily recognise and avoid alkanols unsuitable for the reactions contemplated in particular embodiments.

In this disclosure the term "catalyst" has its usual meaning and means a substance that increases the rate of a chemical reaction without itself suffering any permanent or irreversible chemical change, although those skilled in the art will readily understand that any catalyst may be gradually degraded or exhausted or poisoned or otherwise lose efficacy. In particular embodiments a catalyst is a nano-catalyst, and in embodiments is a heterogeneous catalyst and in alternative embodiments is a homogeneous catalyst. In particular alternative embodiments a catalyst may be loose, or may be mounted on a support, or may be shaped or distributed in a variety of ways. In particular embodiments the exposure of a catalyst to a reaction mixture may be modified in any desirable manner, as will be readily understood and implemented by those skilled in the art. By way of example and not limitation in alternative embodiments catalyst is embedded in filters or confined in flow-through cartridges, or is actively intermixed with reaction mixture, or is distributed on baffles, surfaces, filters, membranes or other supports, or is used in the form of powder, granules, capsules, tablets, ribs, spheres, extrusions, perforated structures, microspheres or pellets, or is embedded in or on any suitable matrix. In particular embodiments a catalyst is a nanocatalyst. Catalysts according to embodiments comprise at least one transition metal compound and in embodiments this is a transition metal oxide. In embodiments such transition metal is selected from the group consisting of Yttrium, Scandium, Vanadium, Hafnium, Niobium, Tantalum and Titanium, and in embodiments such compound, is an oxide. In embodiments the transition metal compound is treated with one or more element selected from the group consisting of Carbon, Nitrogen, Oxygen, Phosphorous, Sulphur and Selenium In alternative embodiments the transition metal compound is a carbide, nitride, oxide, sulphide, phosphide or selenide. In embodiments the catalyst comprises Titanium dioxide and in embodiments it comprises sulphur and in one embodiment the catalyst comprises sulphur-titanium dioxide, which in embodiments is titanium dioxide treated with sulphur and in alternative embodiments is the product of reacting suitable reactive sulphur and titanium compounds.

In this disclosure the term "catalyst" includes nano-catalysts (also referred to as nanocatalysts), and the terms "nano-catalyst" or "nanocatalyst" refer to a catalyst comprising particles with a diameter of up to or less than 0.02nm, 0.03nm, 0.04nm, 0.05nm, 0.06nm, 0.07nm, 0.08nm, 0.09nm, 0.1 nm, 0.2nm, 0.3nm, 0.4nm, 0.5nm 0.6nm, 0.7nm, 0.8nm, 0.9nm, 1 .0nm, 1 .1 nm, 1 .2nm, 1 .3nm,1 .4nm, 1 .5nm, 1 .6nm, 1 .7nm, 1 .8nm, 1 .9nm, 2nm, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm, 10nm, 1 1 nm, 12 nm, 1 3nm, 14nm, 15nm, 16nm, 17nm, 18nm, 19nm, 20nm, 21 nm, 22nm, 23nm, 24nm, 25nm, 26nm, 27nm, 28nm, 29nm, 30nm, 31 nm, 32nm, 33 nm, 34nm, 35nm, 36nm, 37nm, 38nm, 39nm, 40nm, 41 nm, 42nm, 43nm, 44nm, 45nm, 46nm, 47nm, 48nm, 49nm, 50nm, 51 nm, 52nm, 53nm, 54nm, 55nm, 56nm, 57nm, 58nm, 59nm, 60nm, 61 nm, 62nm, 63nm, 64nm, 65nm, 66nm, 67nm, 68nm, 69nm, 70nm, 71 nm, 72nm, 73nm, 74nm, 75nm, 76nm, 77nm, 78nm, 79nm, 80nm, 81 nm, 82nm, 83nm, 84nm, 85nm, 86nm, 87nm, 88nm, 89nm, 90nm, 91 nm, 92nm, 93nm, 94nm, 95nm, 96nm, 97nm, 98nm, 99nm, 100nm . In particular embodiments the particles have a diameter of between0.2 and 500nm, between 0.5 and 500nm, betweenl and 500nm, betweem2 and 300nm, betweenl and 25nm, between 25 and 50nm, between 50 and 75nm, between 75 andl OOnm, between 100 and 125nm, between 125 and150nm, between 150 and 175nm, between 175 and 200nm, between 200 and 225nm, between 225 and 250nm, between 250 and 275nm, between275 and 300nm, between 300 and 325nm, between 325 and 350nm, between 350 and 375nm, between 375 and 400nm, between 400 and 425nm, between 425 and 450nm, between 450 and 475 nm, between 475 and 500nm or greater than 500nm. In embodiments particles have a diameter of between 0.5nm and 30nm, between 0.5 and 25 nm, between 1 nm and 30nm, between 1 nm and 25 nm, between 1 .5nm and 30 nm, between 1 .5nm and 25 nm, between 2nm and 30nm, or between 2nm and 25 nm. It will be understood by those skilled in the art that reference to the "diameter" of a particle or to a catalyst composition comprising particles having a designated diameter, which catalysts may be a nanocatalysts, refers to the approximate average diameter of the particles comprised in a composition or mixture of the catalyst particles. Thus, by way of illustration and not limitation, the statement that a nanocatalyst has a diameter of, for example, about 5nm, does not mean or imply that all particles in the composition necessarily have this diameter, or have exactly this diameter, or that such particles have a uniform diameter, or that the catalyst does not comprise any particles of irregular shape or having different dimensions. It will be understood that in particular embodiments a user may choose to regulate or control the diameter of catalyst particles or the range of particle diameters, in a variety of ways. In this disclosure a reference to the size of a particle will be understood to refer to the diameter of such particle, unless the context requires otherwise. In particular embodiments of catalysts disclosed, the particles of catalyst are substantially or approximately or predominantly spherical. While in embodiments particles are screened to maintain a desired size range, this is not a requirement of the embodiments disclosed.

In this disclosure the term "reactive compound" means a compound capable of reacting as required to generate the desired catalyst or chemical. Thus, by way of example and not limitation, in this disclosure the term "reactive titanium compound" where used with reference to methods to synthesise a titanium dioxide-sulphur catalyst, means any titanium compound suitable for a reaction with a reactive sulphur compound in order to yield a sulphur-titanium dioxide compound of a catalyst according to an embodiment. It will be understood that any more general reference to a sulphur, titanium or other compound, includes suitably reactive compounds, unless the context otherwise requires. In an embodiment a suitable reactive titanium compound is or comprises titanium (IV) isopropoxide, and the reaction is a reaction between thiourea and titanium (IV) isopropoxide. Similarly, the term "reactive sulphur compound", where used with reference to methods to synthesise a titanium dioxide-sulphur catalyst, means any sulphur compound suitable for reaction with a suitable titanium compound in order to yield a sulphur-titanium dioxide compound of a catalyst according to an embodiment. In an embodiment a suitable reactive sulphur compound is or comprises thiourea, and the reaction is a reaction between thiourea and titanium (IV) isopropoxide. Thus in particular embodiments, reactive compounds are compounds of transition metals and include compounds of Yttrium, Scandium, Vanadium, Hafnium, Niobium, Tantalum or Titanium and are suitable to react with reactive compounds of nitrogen, oxygen, phosphorous, sulphur or selenium. In embodiments the transition metal compounds include nitrides, carbides, selenides, sulphides, oxides and phosphides.

In this disclosure the term "ambient" temperature means any temperature within the normal temperate or tropical atmospheric range and in particular embodiments is any temperature above 1 °C, 2°C, 3°C, 4°C, 5°C, 6°C, 7°C, 8°C, 9°C, 10°C, 1 1 °C, 12°C, 13°C, 14°C, 15°C, 1 6°C, 17°C, 18°C, 19°C, 20°C, 21 °C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31 °C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 39°C, 40°C, 41 °C, 42°Cs or higher or is any temperature below 1 °C, 2°C, 3°C, 4°C, 5°C, 6°C, 7°C, 8°C, 9°C, 10°C, 1 1 °C, 12°C, 13°C, 14°C, 1 5°C, 1 6°C, 17°C, 18°C, 19°C, 20°C, 21 °C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31 °C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 39°C, 40°C, 41 °C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C, or 50°C and in particular embodiments "ambient temperature" is a temperature within the ranges between 1 °C and 50°C, or is between 5°C and 40°C, or between 10°C and 35°C, or between 1 5°C and 30°C, or between 15°C and 25°C, or between 5°C and 50°C, or may be between 5°C and 45°C, or between 5°C and 40°C, or between 5°C and 35°C, or between 5°C and 30°C, or between 10°C and 50°C, or may be between 10°C and 45°C, or between 10°C and 35°C or between 10°C and 30°C or between 10°C and 25°C, or may be between 15°C and 50°C, or may be between 15°C and 45°C, or between 1 5°C and 35°C or between 1 5°C and 30°C or between 15°C and 25°C.

In this disclosure "separating" a catalyst from a reactant or product liquid or mixture may be achieved by any suitable methods, all of which will be readily identified and implemented by those skilled in the art. In particular alternative embodiments, separating is achieved by centrifugation, filtration, sedimentation, magnetic separation, precipitation, or any other suitable method or combination of methods.

In particular embodiments of the processes and methods disclosed herein, the resulting biodiesel mixture comprises up to 80%, 81 %, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91 %, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% biodiesel by weight and/or comprises less than 10%, 9.5%, 9%, 8.5%, 8%, 7.5%, 7%, 6.5%, 6%, 5.5%, 5%, 4.5%, 4%, 3.5%, 3%, 2.5%, 2%, 1 .5% or less than 1 % of glycerin or of impurities by weight. In particular embodiments of the processes and methods disclosed herein, the resulting biodiesel mixture comprises up to 80%, 81 %, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91 %, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% biodiesel by volume or comprises less than 10%, 9.5%, 9%,8.5%, 8%, 7.5%, 7%, 6.5%, 6%, 5.5%, 5%, 4.5%, 4%, 3.5%, 3%, 2.5%, 2%, 1 .5% or less than 1 % of glycerin by volume or of impurities by volume.

In this disclosure the terms "sinter" and "sintering" refer to a process wherein a powder which may be a fine or coarse powder, and may be of uniform composition or of non-uniform composition, is molded into a solid without heating the powder above its melting temperature. In particular embodiments this is achieved by heating the powder in the mold to a temperature below its melting point, but in alternative embodiments it will be understood that a range of alternative forms of sintering, including but not limited to thermally driven sintering, pressure driven sintering, liquid phase sintering, electric current assisted sintering, spark plasma sintering and pressureless sintering may optionally be used and will be readily implemented by those skilled in the art.

In this disclosure the term "impurities" means any components whose presence is not generally desired in a fuel or diesel or biodiesel. By way of example and not of limitation, in embodiments impurities include glycerin. In particular embodiments, impurities and degree of purity are quantified in terms of weight, volume, or in such other ways as may be required by the context.

In this disclosure the term "residence time" refers to the time period for which selected chemicals are exposed to reaction conditions, or to a suitable catalyst. In particular embodiments residence time refers to the time period over which an alkanol and biomass oil are held under suitable conditions for transesterification to occur, and in particular embodiments refers to the time period over which reagents are exposed to or intermingled with catalysts according to embodiments. In embodiments the residence time a transesterification reaction is greater than 1 ,

2, 3, 4, 5, 6, 7, 8, 9, 10, 11 , 12, 13, 14, 1 5, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25,

26, 27, 28, 29, or 30 minutes or longer than about 30 minutes. In particular embodiments the residence time for a tranesterification reaction is less than 1 , 2,

3, 4, 5, 6, 7, 8, 9, 10, 11 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26,

27, 28, 29, or 30 minutes. In particular embodiments the residence time for a transesterification reaction is between 1 , 2, 3, 4, 5, 6, 6, 7, 8, 9 or 10 or less minutes and 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 1 6, 1 7, 1 8, 19, 20 or more minutes.

A) An Embodiment:

In an embodiment, there is disclosed a method for the production of biodiesel, the method comprising the step of carrying out a transesterification reaction between biomass oil and alkanol, in the presence of a catalyst comprising a transition metal oxide and an element selected from the group consisting of Carbon, Nitrogen, Oxygen, Sulphur, Phosphorous and Selenium. In one variant of the embodiment the transition metal oxide is Titanium Dioxide and the element is Sulphur. In alternative embodiments the catalyst is a nanocatalyst and in further alternative embodiments the catalyst comprises particles having a diameter of between 1 nm and about 500nm. In alternative embodiments the reaction occurs over a residence time of between 3 minutes and 10 minutes. In alternative embodiments the reaction occurs at a temperature of between 1 5°C and 25°C. In alternative embodiments the biomass oil is derived from a plant source and in further alternative embodiments the plant source comprises one or more of Jatropha Curcas L and algae. In alternative embodiments the alkanol is or comprises an alcohol and in embodiments comprises a) methanol; or b) ethanol; or c) methanol and ethanol. In alternative embodiments the reaction is carried out with a biomass oil to alkanol ratio of about 1 :0.75 to 1 :1 .5 by weight and in embodiments the alkanol is an alcohol and is or comprises ethanol or methanol or both ethanol and methanol.

In a variant of the embodiment there is disclosed a method for the production of biodiesel, the method comprising: carrying out a transesterification reaction between biomass oil and alkanol, in the presence of a heterogeneous catalyst, the catalyst comprising Sulphur-treated Titanium (IV) Dioxide (Ti0₂) . In particular embodiments and without limitation the catalyst is a nano-catalyst, and the particle size of the nano-catalyst is between 1 nm and 500nm, or between 10nm and 500nm, or between 20nm and 230nm . In embodiments the reaction occurs at ambient temperature, and in embodiments the reaction is continued for between 1 and 15 minutes, or for between 3 minutes and 10 minutes. In embodiments the ambient temperature is between 1 5°C and 25°C. In embodiments the biomass oil is derived from a plant source, and in embodiments this comprises Jatropha Curcas L or Algae. In embodiments the alcohol comprises methanol; or ethanol; or methanol and ethanol.

In embodiments the ratio of plant oil to alcohol is in the range of 1 :0.75 to 1 :1 .5 by weight. It will be understood that the catalysts used in the first embodiment and any variants of the first embodiment, comprise any catalysts according to the other embodiments hereof and that such catalysts may be made by any suitable method, including but not limited to the methods disclosed herein.

Example of the embodiment:

In one example of the first embodiment the reaction is carried out batchwise in an apparatus or system schematically shown in FIG. 1 . Broadly, according to the method and apparatus of the embodiment, biomass oil is transferred into a reactor tank and is circulated in a closed circuit. Catalyst is mixed with methanol and the mixture is charged into the reactor while oil is being circulated therethrough. The content of the reactor is mixed by pumping, agitation or otherwise for a desired time period and in alternative embodiments this is or is about 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30 or more minutes. In embodiments the reaction is allowed to proceed at ambient or room temperature. The biodiesel product is decanted from the bottom valve of the reactor and transferred to centrifuge for separation of the catalyst.

The pilot plant of the example is now explained in greater detail with general reference to FIG. 1 and is generally designated 100. It will be seen that the apparatus generally comprises a methanol /catalyst feed, a biomass oil feed, and a reaction portion.

Methanol/catalyst feed: a pipe 121 carries methanol, or such other alcohol or alkanol as may be selected, to tank 1 1 4. Flow of the methanol is driven by a pump 120 which in variant embodiments is a hand pump. Catalyst is held in the tank 1 14 and the tank 1 14 contains an agitator, stirrer or other device to ensure the even suspension of catalyst in the methanol or other chosen alkanol. A recirculation loop 1 16 is provided, comprising recirculation pump 1 16, the recirculation serves to ensure that catalyst remains well dispersed in the methanol. A feed line 124 leads mixed methanol/catalyst to reactor tank 122.

Vegetable oil, which in embodiments is filtered vegetable oil which in embodiments is edible, or non-edible or waste vegetable oil, is charged in the oil barrel 1 10. If a pump is used to transfer the oil then in some embodiments it is a hand pump, and in embodiments is positioned in line 1 12, and in embodiments is primed by filling the barrel to a suitable level and the filtered oil is then transferred into the reactor tank 122. To feed oil from tank 1 10 into the reactor 122, valve 133 is opened while valves 155 and 156 remain closed to isolate the circuit. If a pump is not used to transfer the oil, then oil flow may be driven by gravity with suitable relative positioning of tanks 110 and 122.

Biomass oil feed: Biomass oil is held in a storage tank 1 10 which may be a 55 gallon pre-filter barrel having a 300 micron filter. The tank according to an embodiment is equipped with one or more filters, which may comprise one or more 300 micron filter, to filter the oil either on entry to the tank, or on exit from the tank, or both. Oil is lead off from the tank through pipe 1 12, whence via pipe 1 13, comprising heater /dryer 1 15 it is led to reactor tank 1 22 (which is also referred to as a batch reactor or batch reactor tank). Heater/dryer 1 15 is controlled to warm the oil to a desired temperature, generally in the range of 10°C to 30°C. Heater/dryer 1 15 may be an inline 2000 watt heating and drying system.

Reaction circuit: Reactor tank 122 comprises vent valves and piping collectively designated 123. Oil and methanol are fed into the reactor in desired quantities. An agitator is provided within the reactor tank 122 to ensure vigorous mixing of the reactants and catalyst. It will be understood by those skilled in the art that the degree and means of agitation may be adapted in a variety of ways. The mixed oil, alcohol and catalyst are held in the tank 122 for the desired residence time and the reaction products are then led out of the tank 1 22 through outlet pipe 125 by opening control valve 124 where it joins outflow pipe 126. It will be seen that pipe 126 may be drained directly through pipe 127 or may be drained through pipe 128. As will be seen pipe 126 is also continuous with pipe 1 13 through joining pipe 141 and recirculation pump 1 42 so that with the operation of suitable valves, (namely valve 133 in line 11 2) reagents may be recirculated through reactor 122 and pipe 1 13 and heater 1 15 to ensure continued mixing during the residence period and to maintain temperature stability if desired.

When the reaction is complete or at a desired time, the reaction products are be led off through pipe 128, if desired filtered through a filter 170, which in variant embodiments is or comprises a 300 micron filter, and then dispensed through pipe 180 leading to nozzle 182 and collected in suitable vessels ready for use. It will be seen that valves 1 33, 132, 123 and pumps 120, 1 1 7, 142, may be alternately closed, opened and operated as desired by a user to isolate different regions of the apparatus and activate, deactivate and redirect the flow of reagents as desired.

Thus in operation valve 151 is opened, methanol is fed into tank 1 14 using hand pump 120, and then valve 151 is closed. To recirculate methanol and catalyst through line 1 16, valves 1 53 and 152 are kept open and valve 134 is kept closed to maintain isolation from reactor 1 22. To feed methanol into the reactor 122, valve 1 52 is closed, pump 1 17 is deactivated, and valve 1 54 is opened to allow flow through line 124 into the reactor. To feed oil from tank 1 10 into the reactor 122, valve 133 is opened while valves 155 and 156 remain closed to isolate the circuit. If desired a further pump may be introduced in line 1 1 3 or the flow may be driven by gravity with suitable relative positioning of tanks 110 and 1 22. Once the desired amount of oil has been delivered to the tank 122, valve 1 33 is closed and as desired valve 155 is opened and pump 142 activated to recirculate reagents in the reactor loop for the desired residence time. Once the desired residence time is complete, the pump 142 is deactivated and the valve 155 closed. Valve 124 may be opened to allow reaction products to exit reactor 122. Valve 132 may be opened to directly harvest the biodiesel. Alternatively, valves 156 and 155, 157 may be opened to lead the biodiesel through filter 170 to be dispensed through the nozzle 182.

Those skilled in the art will readily understand that in variant embodiments additional valves, pumps, filters, heaters, agitators and controls may be added at various locations, and that in variant embodiments the operation of the plant may be achieved manually or may be automated or partly automated, all in ways that will be readily understood by those skilled in the art. For example a suitable programmable logic controller may be used to coordinate the operation of the various elements.

In more detail, in one embodiment the apparatus comprises steel plumbing and brass ball valves, a switch panel for the heater and mixing pumps with a pumping capacity of about 12gal/min, and an electric catalyst mixing system. In a variant embodiment filters are provided and in one embodiment may optionally include a MIS™, 10 micron WIX™ fuel filter. Output may be delivered using a 10 foot long fuel hose and steel fuel nozzle coupled with a downstream centrifuge.

In an embodiment positive displacement, piston pumps are employed to circulate the liquid. The pumping rate is variable and is dictated by the desired throughput of the biodiesel product. The rates of the individual feed streams are dictated by the reaction stoichiometery via a ratio control prescribed through the control console of the device. The inlet diameters of pumps in an embodiment are typically be in the range of 10 to 20mm and the exit diameters up to about 50mm although other dimensions will be readily adopted by those skilled in the art. The control console where provided comprises a programmable logic controller or any other suitable control device, all of which will be readily identified and implemented by those skilled in the art. Valves employed to control liquid flow in the batch system will typically be of ball, butterfly or plate-and-vane type and in embodiments are manually operated and in embodiments are centrally operated using suitable control systems. Where provided filter assemblies may optionally be arranged in series.

In embodiments the transesterification batch reactor is fabricated out of transparent material, suitable materials include perspex, polycarbonate, and high density polyethylene and in some embodiments the reactor tank is Perspex. In one embodiment a conventional impeller stirring method is used to intermingle the catalyst and alkanol. In an embodiment the circulation pump is allowed to operate for a residence time of five minutes, following which the biodiesel product is decanted from the bottom valve of the reactor and transferred to a suitable centrifuge for separation of the catalyst. Fine filtration is achieved in a centrifuge. In one example the capacity for the batch centrifuge is about 500 ml/ampoule and the centrifuge operates at up to about 10000 rpm . In alternative embodiments the capacity may be higher or lower and the centrifuge may operate at up to or less than about 5000rpm or about, 6000, 7000, 8000, 9000, 10,000, 1 1 ,000, 12,000, 13,000 14,000, or about 15,000rpm . Biodiesel is decanted as the final product.

B) A further embodiment:

In further embodiment the process and apparatus are adapted to implement continuous production of biodiesel and this is achieved in embodiments by using a combination of impingement mixing / static mixing with online separation of biodiesel and glycerin. An example of a continuous production embodiment is generally illustrated in FIG. 4.

Referring to FIG. 4 a continuous flow embodiment is generally designated 300. Biomass oil is held in storage tank 210 and methanol in storage tank 220. Oil is fed through pipe 21 1 and its flow controlled by centrally regulated valve 212. Alkanol/catalyst mixture, which in one embodiment is a methanol/catalyst mixture is fed through pipe 221 and regulated by valve 21 1 . These reagents are brought together at high speed through opposed ends 231 , 232 of impingement device 230 using suitably regulated pumps which are not shown in the Drawing but in embodiments are positioned proximate opposed ends 231 and 232 of the impingement device. The thus mixed reagents are led off through pipe 240 into static mixer 240 and thence out through pipe 252. The discharge pipe 240, of the embodiment is transparent and is lined with static mixing elements to ensure continued intermingling of the reactants as the flow through the pipe. In one embodiment length of the pipes 240 and 252 are selected to satisfy, in combination with the selected flow rate, the selected residence time for the transesterification reaction. It will be appreciated that as an alternative to static mixing elements a variety of active mixing devices may be employed to ensure continued mixing of the reagents. Those skilled in the art will readily recognize and implement all such systems. In embodiments chamber 230 has volume of about 1000cm³. It will be understood that the rates of flow will be centrally controlled to ensure that the residence time of the reaction mix is as desired and to maintain desired reaction conditions.

Outflow line 252 leads to a centrifuge 260 from which the biodiesel 270, glycerin 280 and catalyst are constantly drawn off. It will be apparent that catalyst will normally be recirculated into the methanol tank 220. It will be understood that in embodiments it is necessary or desirable to wash, dry, clean or otherwise regenerate the catalyst from time to time, and this process will be readily understood and carried out by those skilled in the art.

The action of the two pumps is coordinated as may be required to ensure that reagents are mixed in suitable ratios and in particular embodiments such coordination is achieved by using a common motor drive or drives, or other suitable control mechanism . The mixing point or impingement device 230 of the illustrated embodiment comprises a small volume where the components may be mixed in a variety of ways. In one embodiment the mixing comprises head-on impingement of the two streams. High velocity head-on impingement of the reactant streams in the embodiment is carried out in a mixing cavity or chamber having any suitable volume. In one example the mixing cavity has a volume of about 1000 cubic centimeters, and those skilled in the art will understand that a variety of volumes and configurations for the mixing cavity may be possible or desirable and will choose between them to suit desired flow rates and other reaction parameters. In embodiments the Reynolds number of one or both of the reagent streams are independently be greater than or less than 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1 100, 1200, 1300, 1400, 1500, 1600 and higher values. In embodiments liquids are mutually contacted at pressures of up to or less than 100 psi, or up to or less than 200, 200, 300, 400, 600, 700, 800, 900, 1000, 1 100, 1200, 1 300 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000 or higher or at pressures in the 500-2000 psi range. Typically, in embodiments, the flow rates reside in the 5-50 L/min range.

It will be understood that parameters such as flow rate, pipe diameters, pressure and the like may all be adjusted to achieve desired reaction conditions and durations. Those skilled in the art will readily adjust the operating parameters and design of the system to achieve the desired performance characteristics.

It is expected that a continuous production system will use pneumatically controlled valves in the feed stream and will use non-return valves for the recirculation streams. In embodiments the valves are protected against overpressures through suitably calibrated bursting diaphragms.

In one example of a proposed continuous production system it is expected that impingement mixing will be carried out at Reynolds numbers of up to or above 1000 and at pressures in the range of 500-20, OOOpsi, with flow rates in the region of 5 to 50 litres per minute. Those skilled in the art will readily adjust these parameters as necessary or desirable to respond to particular reaction requirements.

It is envisaged that in embodiments the resulting biodiesel will be processed to separate out catalyst and by-products such as glycerin. In selected embodiments this will be achieved by filtration, or by centrifugation or both, or will be achieved using other conventional methods, all of which will be readily recognized and implemented by those skilled in the art. It is envisaged that where filters are employed then in embodiments these will be provided in series. It is further envisaged that a preliminary filtration step to recover catalyst will optionally be followed by a glycerin separation step utilizing an online centrifuge. In embodiments the centrifuge will also be used to simultaneously separate out the catalyst. For continuous mode centrifugation a capacity of about 10 L/min is envisaged with the centrifuge operating at up about to 10000 rpm. In embodiment the capacity is optionally higher or lower and the centrifuge according to embodiments will operate at up to or less than 5000rpm or, 6000, 7000, 8000, 9000, 10,000, 1 1 ,000, 1 2,000, 13,000 14,000, or 15,000rpm .

The molar ratio of alkanol; plant oil (which in embodiments is a ratio of alcohol to plant oil and in embodiments is a ratio of ethanol or methanol to plant oil or of ethanol or methanol to plant oil) in embodiments is in the range of 1 .75 to 0. 25, or 1 to 0.5, and or 0.9-1 .0. The method according to one series of embodiments employs a heterogeneous catalyst comprising sulphur Ti0₂ produced through the sol-gel method or alternatively uses other suitable catalysts comprising a transition metal compound. In embodiments this is a transition metal oxide and the catalyst also comprises an element selected from the group consisting of carbon, nitrogen, oxygen, phosphorous and selenium. In embodiments liquid precursors are reacted with sulphur containing compounds under vigorous agitation followed alcoholysis and sintering to produce a catalyst comprising particles which in embodiments have diameters in the range of 2nm to 22nm. The quantity of nano- catalyst used in a reaction of particular embodiments is in the range of 0.05 to 1 .0 percent by weight of the of the reaction mass or in the range of 0.1 to 0.75 percent by weight of the reaction mass. The reaction mixture containing the catalyst is agitated over a residence time of between 1 minute and 10 minutes, and in particular embodiments is agitated for about 3 minutes to 7 minutes. In embodiments the reaction temperature is within a range between 5°C and 30°C, or between about 10°C and about 25°C.

The biodiesel produced may be processed in a conventional centrifuge to separate out the catalyst from the biodiesel product. The biodiesel according to embodiments is useable to operate a conventional diesel engine without modifications. It will be understood that in alternative embodiments the transition metal compound may be a carbide, oxide, phosphide, nitride, sulphide or selenide. C) A Further Embodiment:

In a further series of embodiments there are disclosed catalysts for the transesterification of biomass oil and alkanol. In alternative embodiments the alkanol is an alcohol and in embodiments is or comprises, ethanol or methanol, or ethanol and methanol the catalyst comprising a transition metal compound which in embodiments is an oxide and further comprising an element selected from the group consisting of Carbon, Oxygen, Nitrogen, Phosporous, Sulphur and Selenium. In embodiments the transition metal compound is a carbide, oxide, phosphide, nitride, sulphide or selenide. In embodiments where the transition metal compound is an oxide then the additional element is selected from the group consisting of carbon, nitrogen, phosphorous, sulphur and selenium . In variants of the embodiments the transition metal oxide is titanium dioxide and the element is sulphur. In variants of the embodiments the catalyst comprises particles between 1 nm and 500nm in diameter. In a variant of the second embodiment there is disclosed a Sulphur-Titanium Dioxide catalyst for the transesterification of biomass oil and alcohol which in embodiments is a nano- catalyst according to other embodiments and in embodiments comprises particles between 20nm and 230nm in diameter.

In a series of alternative embodiments there are disclosed methods for making the catalyst according other embodiments, the methods comprising the step of contacting a transition metal oxide with a solution of the element. In alternative embodiments the method comprises the step of sintering the element treated transition metal oxide.

In an alternative embodiment there is disclosed a method for making a catalyst the method comprising the step of reacting a reactive compound of sulphur, nitrogen, oxygen, phosphorous, carbon or selenium with a reactive transition metal compound. In one variant of the embodiment the compounds are thiourea and titanium isopropoxide and the catalyst is a sulphur-titanium dioxide catalyst. In variant embodiments the methods comprise the step of sintering the solid reaction product at a temperature of between about 400°C and about 500°C for between about 3 hours and about 5 hours.

In further variants of the embodiments there is disclosed a method for making a sulphur-titanium dioxide catalyst for the transesterification of a biomass oil and an alkanol. In embodiments the alkanol is an alcohol and in embodiments comprises methanol or ethanol, or both methanol and ethanol. In embodiments the method comprises reacting a reactive sulphur compound with a reactive titanium compound. In a further variant of the embodiment there is disclosed a method for making the catalyst according to embodiments, wherein said method comprises the steps of: agitating nano sized Titanium (IV) Dioxide in a solution of Sulphur; sintering the Sulphur-treated Titanium (IV) Dioxide. In a further variant of the embodiment there is disclosed an alternative method comprising: reacting a sulphur containing compound with titanium (IV) isopropoxide separating out the solid product, and sintering the solid product at 400°C-500°C for about 3 to 5 hrs. Example of the embodiment:

In an example of the method for making catalyst, Sulfur-treated titanium dioxide (S-Ti0₂) is prepared by the following steps: Dissolve Thiourea in ethanol followed by drop-wise addition of titanium (IV) isopropoxide and vigorously stir to yield a white precipitate. Remove solvent heat the remaining white powder as necessary. This powder of nanoparticles may them be washed to remove residual surface impurities. Sulphur treatment of the nanoparticles may be performed by agitating the said nanoparticles in a solution of sulfur using a ball mill, followed by filtration, removal of solvent and subsequent sintering. In embodiments sintering may be carried out at a temperature of between about 400 and 500°C for a period of about 3 to 5 hours. It will be understood however that in embodiments higher or lower temperatures, and longer or shorter sintering periods are suitable. For example in embodiments a temperature of between 300°C and 350°C, between 350°C and 400°C, between 400°C and 450°C, between 450°C and 500°C, between 500°C and 550°C, between 550°C and 600°C, or greater than 600°C are suitable. Likewise, in embodiments sintering is continued for up to about 2, 3, 4, 5, 6, 7, 8, 9 or more hours.

Example of a catalyst and its production according to the embodiment:

More specifically, in an example of catalyst and catalyst production according to the second embodiments, Sulfur-treated titanium dioxide (S-Ti0₂) was prepared by dissolving 1 10.3 g of thiourea in 950 mL of 90% ethanol followed by drop-wise addition of 1 1 3.5ml of titanium (IV) isopropoxide and vigorously stirring the mixture. A white precipitate was observed. The solution was stirred at room temperature under aerated conditions for 36 hours to allow for complete hydrolysis. In embodiments stirring may be continuous, may be at a temperature of between about 10°C and about 30°C and may be achieved using an impeller type stirrer which may be operated at about l OOOrpm.

Solvent was evaporated under partial vacuum and then condensed for recycling.

The precipitated white powder was heated at about 450°C for about 4 hours. The powder was then washed thoroughly with distilled and deionized water over a vacuum filter to remove residual surface adsorbates and any surface sulfates.

When dried, S-Ti0₂ was obtained as a vivid yellow powder.

SEM analysis showed that the catalyst comprised particles with diameters between 2nm and 22 nm . In variants of the example of an embodiment, Sulphur treatment of the nanoparticles may be performed by agitating the nanoparticles in a solution of sulfur using a ball mill, followed by filtration, removal of solvent and subsequent sintering at 400-500°C for a duration of about 3 to 5 hours. The resulting pale yellow powder is ground and preserved for use in embodiments.

XRD (X-ray diffraction) analysis of the heterogeneous nano-catalyst prepared by the method of the example is presented in FIG. 5.

D) A Further Embodiment:

In a further series of embodiments there is disclosed biodiesel made using the methods according to embodiments and/or using the catalyst according to embodiments. In variant embodiments biodiesel comprises less than about 5% impurities. In particular variants the biodiesel comprises less than about 1 5, 14, 13, 1 2, 1 1 , 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 % impurities. In embodiments there is disclosed biodiesel according to embodiments with a flash point of between 120°C-1 50°C and a cloud point of less than 5°C below zero. Examples:

Hereafter by way of example and not limitation, are described examples of embodiments. Examples of Biodiesel according to the embodiments:

A GC (gas chromatograph) spectrum of biodiesel produced by the method and procedures of the exemplary embodiments is shown in FIG. 3.

Referring to FIG.3, the peak obtained at a retention time of about 4.6 minutes in GC spectrum represents glycerine. The second peak appearing at about 5.5 minutes represents butanetriol. The peaks indicative of monoglycerides, diglyceride and triglycerides appear in the form of groups ranging over retention times of about 1 5.9-16.4, 20-21 .3 and 23-24.4 minutes respectively. Similarly peaks representing mono-1 , mono-olein, mono-2,mono-3 and tricaprine appear at retention times of about 1 5.5, 16.3, 17.0, 18.5 and 19.1 minutes respectively. A biodiesel sample produced by the preferred embodiments of the present invention was analyzed by FTI R (Fourier Transform Infrared Spectroscopy) and compared with the one produced through a traditional hydroxide route, with an algal oil based sample and with a sample of natural or petro diesel. The results are shown in FIG. 2. Referring now to FIG. 2, trace A is a sample of Petro Diesel, trace B is a sample of post heating Biodiesel, trace C is Standard Biodiesel, trace D is biodiesel prepared from Jatropha seed according to an embodiment and trace E is biodiesel prepared from Rapeseed according to an embodiment.

In embodiments, the biodiesel has a flash point at above or below 50°C, or above or below 60°C, 70°C, 80°C, 90°C, 100°C, 1 10°C, 120°C, 130°C, 1 40°C, 150°C, 160°C, 170°C, 180°C, 190°C, or 200°C. In particular embodiments the biodiesel has a flash point of between 100°C and 200°C, between 1 10°C and 190°C, 120°C and 1 80°C, 130°C and 1 60°C, or 120°C and 150°C. In embodiments, the biodiesel has a cloud point of less than about 0°C or less than minus 1 °C, minus 2°C, minus 3°C, minus 4°C minus 5°C, minus 6°C, minus 7°C, minus 8°C, minus 9°C, minus 10°C, minus 1 1 °C, or minus 1 2°C. In embodiments the biodiesel has a cloud point between minus 2°C and minus 8°C and in embodiments has a cloud point between minus 4°C and minus 6°C.

The following additional examples are presented to further illustrate the subject matter hereof. Example 1

Biodiesel produced by a conventional method using hydroxide catalyst was analyzed for flash point, cloud point, and other significant parameters. The results are compared with equivalent measurements of biodiesel produced according to the example. The results are set out in Table 1 . Samples AB-09, AB-10, AB-1 1 and AB-12 are of biodiesel made using Sulphur-Titanium Dioxide catalyst. B100 limits are also shown for comparison.

Table 1 . Comparison of biodiesel produced using Sulphur-Titanium Dioxide catalyst according to embodiments, and biodiesel produced using a conventional hydroxide catalyst.

Example 2 Biodiesel produced using heterogeneous Sulphur-Titanium Dioxide catalyst for various oil to methanol ratios was analyzed with respect to flash point. The results are presented in Table 2.

Table 2. Effect of oil to methanol ratio on Flash point of Biodiesel

Example 3

Biodiesel produced using Sulphur-Titanium Dioxide catalyst at various oil to methanol ratios and various temperatures was analyzed with respect to flash point. The data are presented in Table 3.

Table 3. Effect of oihmethanol ratio and temperature on flash point of biodiesel.

Example 4

Biodiesel produced according to embodiments using heterogeneous Sulphur- Titanium Dioxide catalyst in combination with various oihmethanol ratios and temperatures was analyzed with respect to flash point. Data are presented in Table 4.

Table 4. Effects of oihmethanol ratio and temperature on the flash point of biodiesel.

05 1 :6 (Conventional) 70^UC 177

The embodiments and examples presented herein are illustrative of the general nature of the subject matter claimed and are not limiting. It will be understood by those skilled in the art how these embodiments can be readily modified and/or adapted for various applications and in various ways without departing from the spirit and scope of the subject matter disclosed and claimed. The claims hereof are to be understood to include without limitation any alternative embodiments and equivalents of the subject matter hereof. Phrases, words and terms employed herein are illustrative and are not limiting. Where permissible by law, all references cited herein are incorporated by reference in their entirety. It will be appreciated that any aspects of the different embodiments disclosed herein may be combined in a range of possible alternative embodiments, and alternative combinations of features, all of which varied combinations of features are to be understood to form a part of the subject matter claimed. Particular embodiments may alternatively comprise or consist of or exclude selected ones or pluralities of the elements disclosed.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

A method for the production of biodiesel, the method comprising the step of carrying out a transesterification reaction between biomass oil and an alkanol, in the presence of a catalyst comprising:

a transition metal compound selected from the group consisting of a carbide, oxide, nitride, sulphide, phosphide, and selenide; and

an element selected from the group consisting of carbon, nitrogen, oxygen, sulphur, phosphorous and selenium .

The method according to claim 1 wherein the transition metal compound is Titanium dioxide and the element is sulphur.

The method according to claim 1 wherein the catalyst comprises particles having a diameter of between about 1 nm and about 500nm.

The method according to any one of claims 1 through 3 wherein said reaction occurs over a residence time of between about 3 minutes and about 10 minutes.

The method according to claim 1 wherein said reaction occurs at a temperature of between about 15°C and about 25°C.

The method according claim 1 , where the biomass oil is derived from a plant source.

The method according to claim 6 wherein the plant source comprises one or more of Jatropha Curcas L and algae.

The method according to claim 6 wherein the alkanol comprises

a) methanol; or

b) ethanol; or

c) methanol and ethanol.

The method according to claim 1 , wherein the reaction is carried out a biomass oil to alkanol ratio of about 1 :0.75 to 1 :1 .5 by weight.

A catalyst for the transesterification of biomass oil and an alkanol, the catalyst comprising:

a transition metal compound selected from the group consisting of a carbide, oxide, nitride, sulphide, phosphide, and selenide; and an element selected from the group consisting of carbon, nitrogen, oxygen, sulphur, phosphorous and selenium .

1 1 ) The catalyst according to claim 10 wherein the transition metal compound is titanium dioxide and the element is sulphur.

12) The catalyst according to claim 10 comprising particles between about 1 nm and about 500nm in diameter.

13) A method for making the catalyst according to claim 10, said method comprising the step of contacting the transition metal oxide with a solution of the element.

14) The method according to claim 13 further comprising the step of sintering the element treated transition metal oxide.

15) A method for making a titanium dioxide-sulphur catalyst according to claim

10, said method comprising the step of reacting a sulphur containing compound with titanium (IV) isopropoxide.

16) The method according to claim 15 further comprising the step of sintering the solid reaction product at a temperature of between about 400°C and about 500°C for between about 3 hours and about 5 hrs.

17) Biodiesel made using the method according to claim 1 .

18) Biodiesel made using the catalyst according to claim 10.

19) Biodiesel according to claim 18 comprising less than about 5% impurities. 20) Biodiesel comprising according to claim 19 with a flash point of between about 120°C-1 50 C and a cloud point of less than about 5°C below zero.