CN111575066A

CN111575066A - Liquid biofuel composition

Info

Publication number: CN111575066A
Application number: CN202010410389.2A
Authority: CN
Inventors: B.帕瓦格奥; 齐玲; J-C.卡斯坦; R.塔德莫里; H.费伊; R.格雷塞尔
Original assignee: Rhodia Operations SAS
Current assignee: Rhodia Operations SAS
Priority date: 2014-12-23
Filing date: 2014-12-23
Publication date: 2020-08-25
Also published as: WO2016101114A1; US20180002621A1; EP3237584A4; EP3237584A1; CN107429179A

Abstract

A liquid biofuel is disclosed comprising D having a range from 0.1 to 200 μm suspended in a liquid biodiesel composition₅₀The carbonaceous material particles of (2).

Description

Liquid biofuel composition

Technical Field

The present invention relates to the field of biofuel compositions.

Background

Recent emphasis on finding alternative energy sources has led to the accelerated search for new fuels or new fuel sources. The production of liquid fuels from biomass or biofuels is an important focus of many alternative energy strategies. The production of ethanol from plant biomass is one example of this. Another example of a newer fuel is biodiesel. Refined vegetable oils have been a typical starting material for the production of biodiesel. Biodiesel can be produced from oils of many plants. Biodiesel is an alternative, non-toxic, biodegradable and renewable diesel fuel. These characteristics of biodiesel reduce the emissions of carbon monoxide, hydrocarbons, and particulate matter in the exhaust gas as compared to diesel fuel.

Biodiesel is commonly referred to as Fatty Acid Methyl Esters (FAME) which are typically obtained from renewable resources such as various vegetable oils (including rapeseed oil, soybean oil, palm oil, etc.), animal oils (including beef tallow, etc.), and waste cooking oils, etc. Biodiesel production relies on a chemical reaction (known as transesterification) that converts esters (such as triglycerides) into monoalkyl esters. Conventionally, this reaction requires a very large excess of methanol, or in some cases ethanol, and an acid or base catalyst under heating. Since biodiesel has physical properties similar to diesel, it can be used in a compression-ignition type diesel engine instead of or in combination with diesel. That is, biodiesel can be defined as an alternative fuel to diesel, which is produced by the chemical reaction of animal or vegetable fatty acids with methanol.

Thus, the production and use of biodiesel increases over time, as an alternative renewable energy source due to depletion of petroleum energy resources and reduction of carbon dioxide production caused by overuse of fossil fuels.

Thus, biodiesel is a clean, safe, ready-to-use alternative fuel that can be operated in any diesel engine without modification.

Further, in view of the anticipated shortage of crude oil as fuel (due to the decline in natural reserves worth producing on the one hand and the need to use it as a chemical feedstock on the other hand), energy recovery processes in which aqueous coal suspensions are subjected to high temperature combustion have recently become increasingly important. Aqueous coal or bio-coal suspensions offer a major advantage over coal in solid (even finely dispersed) form in that these suspensions can be transported over relatively long distances at relatively low cost in transport systems known from crude oil transport, such as pipelines or onshore pipelines. However, a disadvantage is that the dispersion medium, water, which is inert to combustion, reduces the total calorific value of the aqueous coal or biocoal suspension. In the case of the coal content of the aqueous coal or biological coal suspension, an excessive particle content must be avoided in view of transportability, whereas as high a particle content as possible is desirable in view of the gross calorific value.

It is known from the prior art that aqueous coal or bio-coal suspensions can be provided with additives which improve the flowability during transport in pipelines, but on the other hand allow an increase in the coal or bio-coal content of the suspension and thus a significant increase in the gross calorific value. Such additives also improve the combustion characteristics of the aqueous coal suspension. Given the suitable sieve analysis of the coal or biocoal used to prepare the coal suspension, it is possible to produce a readily pumpable suspension having a particle content of from 10 to 50% by weight.

However, it is generally desirable to further increase the particle content in order to increase the overall heating value of the aqueous coal or bio-coal suspension, since the aqueous coal or bio-coal suspension can be economically used in industrial combustion processes for energy recovery only when the substantial particle content of coal by weight is exceeded based on the total weight of the suspension. Furthermore, it is desirable to further reduce the viscosity of the aqueous particle suspension to provide convenient transport even through a pipe having a relatively narrow cross-section. It is also generally desirable to obtain coal or bio-coal suspensions with high stability over time.

Disclosure of Invention

The present invention relates to a liquid biofuel comprising a D having a value ranging from 0.1 μm to 200 μm suspended in a liquid biodiesel composition₅₀The carbonaceous material particles of (2).

In some embodiments, the carbonaceous material particulate content is at least 10% w/w of said biofuel, preferably at least 20% w/w of said biofuel, and most preferably at least 30% w/w of said biofuel.

In some embodiments, the carbonaceous material particles consist of calcined biomass, preferably calcined wood particles.

In some embodiments, the liquid biofuel further comprises additional water in an amount ranging from 0.5% w/w to 25% w/w.

In some embodiments, the liquid biofuel does not comprise any added surfactant compounds.

Drawings

Figure 1 illustrates the viscosity of a liquid biofuel in the form of an oil-in-water emulsion. The abscissa: shear rate, expressed as 1/s; ordinate: viscosity, expressed as pa.s. Curve o: O/W emulsion of LOF biofuel with 10% W/W water; curve ●: an O/W emulsion of LOF biofuel with 20% W/W water; curve □: O/W emulsion of Malaysian biofuel with 10% W/W water; curve ■: O/W emulsion of Malaysian biofuel with 20% W/W water

Detailed Description

The inventors have envisaged specific liquid biofuel compositions comprising a large amount of particles of biomass material which are stable without the requirement for added stabilizing additives such as surfactant compounds or viscosity agents.

Surprisingly, the inventors herein have shown that when liquid biodiesel is used instead of fossil fuel, a stable liquid biofuel composition comprising a significant amount of carbonaceous material particles is obtained without requiring any added stabilizing additives, such as surfactant compounds or viscosity agents.

Accordingly, the present invention provides a stable biodiesel-based liquid biofuel composition comprising suspended carbonaceous material particles.

When such finely ground carbonaceous material particles are used, it is expected that (i) rapid settling of these particles in the liquid biofuel on standing and (ii) aggregation of the settled particles at the bottom of the vessel due to a phenomenon known as particle association.

However, the inventors have unexpectedly shown that liquid biofuels as described herein last for a significant period of storage time without undergoing settling (sedimentation) of the carbonaceous material particles contained therein.

Indeed, detectable deposition of these carbonaceous material particles can be observed after long periods of storage of the liquid biofuel as described herein, i.e. after several months of storage without stirring the liquid biofuel. However, particle deposition over storage time does not constitute a significant disadvantage of liquid biofuels as described herein.

Importantly, the inventors have shown that particles of carbonaceous material contained in a liquid biofuel as described herein remain dispersible over time, even after very long periods of storage time.

Thus, according to an important feature of liquid biofuels as described herein, carbonaceous material particles that can deposit over long periods of storage time are less subject to aggregation and remain dispersible when the liquid biofuel is agitated or pumped.

Further, the inventors have shown that the rheological properties of the liquid biofuel as described herein fully meet the requirements for processability, and in particular pumpability, of the liquid fuel composition.

Notably, the inventors have shown that liquid biofuels as described herein behave as "shear-thinning" liquids, i.e., having a fluid flow resistance that decreases with increasing shear stress rate.

It can be readily appreciated that the shear-thinning properties of liquid biofuels as described herein are important features because it allows liquid biofuels to be easily pumped even after long periods of storage time without requiring high amounts of energy.

In view of the above, it has been shown according to the present invention that liquid biofuels meeting various processability and regulatory requirements can be prepared from liquid biodiesel supplemented with small sized carbonaceous material particles.

Biodiesel oil

As intended herein, the term "biodiesel" refers to vegetable oil-based or animal fat-based diesel fuels composed of long chain alkyl esters, including long chain methyl esters, long chain ethyl esters, and long chain propyl esters. Conventionally, biodiesel is prepared by chemically reacting lipids contained in vegetable oils or animal fats with alcohols (e.g., methanol, ethanol, propanol) for producing the corresponding fatty acid esters.

Within the present description, it is understood that the liquid biodiesel composition does not contain any fossil fuel and therefore does not contain any fuel originating from non-renewable sources. Thus, the term biodiesel refers to a biodiesel composition that does not contain fossil fuels.

Biodiesel materials, such as methyl esters of fatty acids derived from vegetable or animal fats, are conventionally made by liberating the fatty acids from glycerol (e.g., via a transesterification process). Exemplary methods are described in U.S. Pat. nos. 6,399,800; 6,348,074, respectively; 6,015,444, respectively; 6,203,585, respectively; 6,174,501; 6,235,104, respectively; and 7,270,768, each of which is incorporated by reference herein in its entirety. In a typical mechanism, animal or vegetable fats and/or oils (composed of triglycerides-esters containing both fatty acids and glycerol) are reacted with an alcohol such as ethanol or methanol. A base may be used to deprotonate the alcohol to accelerate the reaction, while heat and a catalyst (e.g., a basic catalyst-typically a strong base such as sodium hydroxide or potassium hydroxide) may be used to accelerate the reaction. Because the transesterification reaction is an equilibrium reaction, the reaction is often incomplete, and the yield of biodiesel product can vary significantly (e.g., 40% -90%) depending on the reactants, catalysts, temperature and pressure conditions, and the amount of time allowed to pass. The organic groups of the ester are exchanged with the organic groups of the alcohol by a transesterification reaction, which in the case of triglycerides results in the formation of alkyl esters and crude glycerol. Thus, in the production of biodiesel, significant amounts of waste streams are generated, which may include glycerol, water, fatty acids and/or salts of free fatty acids, methanol, free glycerol, soaps, unconverted mono-and diglycerides, and/or other polar compounds, requiring additional separation/processing steps to obtain a usable biodiesel product, while also creating disposal issues with respect to the waste streams. As defined herein, the term "crude biodiesel product" includes the direct product of a transesterification reaction (e.g., a product that has not been subjected to extensive modification and/or separation processes).

Chemically, triglycerides consist of three long chain fatty acid molecules linked by glycerol molecules. The biodiesel process uses a sodium or potassium hydroxide catalyst (lye) to break down the glycerol molecules and combine each of the three fatty acid chains with a methanol molecule, producing a monoalkyl ester or Fatty Acid Methyl Ester (FAME) -biodiesel. The glycerin byproduct sinks to the bottom and is removed. This process is called transesterification.

A common international standard for biodiesel is EN 14214.

Additional national specifications also exist. ASTM D6751 is the most common standard cited in the united states and canada. In germany, the requirements for biodiesel are specified in the DIN EN14214 standard and in the uk in the BS EN14214 standard, however these last two standards are essentially identical to EN14214 and are prefixed only by the respective national standards agency code.

There are standards for three different varieties of biodiesel, which are made from different oils:

ME (rapeseed methyl ester, according to DIN E51606)

PME (plant methyl ester, pure plant product, according to DIN E51606)

FME (fatty methyl esters, plant and animal products, according to DIN V51606)

These criteria ensure that the following important factors in the fuel production process are met:

-complete reaction.

-removing the glycerol.

Removal of the catalyst

-removal of the alcohol.

-free fatty acids are not present.

Low sulphur content.

In some embodiments of a liquid biofuel as described herein, the liquid biodiesel composition is based on esterified fats and/or oils derived from a group comprising animals, plants, fungi or algae.

In some embodiments of the liquid biofuel as described herein, the liquid biodiesel composition comprises one or more esterified fatty acids, wherein the one or more fatty acids are selected from the group consisting of lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, arachidic acid, gadoleic acid, behenic acid, erucic acid, lignoceric acid, and nervonic acid.

In some embodiments of the liquid biofuel as described herein, the liquid biodiesel composition comprises esterified fatty acids selected from those represented primarily in the group consisting of oleic acid, linoleic acid, linolenic acid, palmitic acid, stearic acid, and gadoleic acid.

In some embodiments of the liquid biofuel as described herein, the liquid biodiesel composition is based on esterified oils derived from the group comprising soybean oil, sunflower oil, rapeseed oil, olive oil, rapeseed oil and palm oil.

In some embodiments of a liquid biofuel as described herein, the liquid biodiesel composition comprises or even consists essentially of esterified palm oil.

In some embodiments, the starting liquid biodiesel composition comprises triglycerides, advantageously at a final concentration complying with the biodiesel standard, including a final concentration complying with european standard EN 14214.

In some embodiments, the starting liquid biodiesel composition comprises a triglyceride content of at most 0.2% by weight of the total weight of the starting liquid biodiesel composition.

In some embodiments, the triglycerides contained in the starting liquid biodiesel comprise one or more triglyceride compounds having fatty acid chains that may be the same or different, i.e., two fatty acid chains are the same and the third fatty acid chain is different from the other two, or three fatty acid chains are different.

In some embodiments of the triglyceride compounds, the fatty acid chains have a number of carbon atoms ranging from 4 to 26, advantageously ranging from 8 to 22, including a number of carbon atoms ranging from 8 to 18.

In some embodiments of these triglyceride compounds, the fatty acid chains contained therein comprise saturated fatty acid chains.

In some embodiments of these triglyceride compounds, the fatty acid chains contained therein comprise unsaturated fatty acid chains including monounsaturated fatty acid chains and polyunsaturated fatty acid chains, advantageously polyunsaturated fatty acid chains having a number of double bonds ranging from 1 to 3, and preferably polyunsaturated fatty acid chains having a number of double bonds ranging from 1 to 2.

In some embodiments, the starting liquid biodiesel composition comprises free fatty acids, notably having a number of carbon atoms ranging from 7 to 13.

In some embodiments, the starting liquid biodiesel composition is produced from a mixture of two or more biodiesel compositions, meaning that the starting liquid biodiesel consists of a blend composition.

In some embodiments, the starting liquid biodiesel composition results from the blending of two or more biodiesel compositions selected in the group comprising (i) a biodiesel composition derived from palm stearin, preferably from Refined Bleached and Deodorized (RBD) palm oil, (ii) a biodiesel composition derived from spent cooking oil, and (iii) a biodiesel composition derived from palm oil methyl ester.

Advantageously, the starting liquid biodiesel composition comprises a biodiesel composition derived from waste cooking oil.

According to these embodiments, the final content of waste cooking oil in the starting liquid biodiesel composition ranges from 20% by weight to 100% by weight, based on the total weight of said starting liquid biodiesel composition, which includes a final content of waste cooking oil ranging from 50% by weight to 100% by weight, based on the total weight of said starting liquid biodiesel composition.

These embodiments include at least 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, based on the total weight of the starting liquid biodiesel composition, 98% and 99% by weight of waste cooking oil.

Without wishing to be bound by any particular theory, the inventors believe that the presence of waste cooking oil in the starting liquid biodiesel composition helps to maintain stable properties of the liquid biofuel composition as described herein over an extended period of time.

An illustrative well-known liquid biodiesel composition containing waste cooking oil is Malaysian biodiesel, which has been used in the examples herein. The Malaysian liquid biodiesel composition comprises a biodiesel composition derived from palm stearin, a biodiesel composition derived from palm oil methyl ester and a biodiesel composition derived from waste cooking oil.

As used herein, the expression "biodiesel composition derived from. In some embodiments, the feedstock comprises at least fatty acids that are processed by transesterification to obtain a liquid biodiesel composition that can be used to prepare a biofuel composition as described herein.

Carbonaceous material

As used herein, the term "carbonaceous" refers to a material that contains carbon.

The carbon content of carbonaceous material particles useful for the present invention is typically more than 30 wt.%, based on the total weight of these carbonaceous material particles; it is often higher than 40 wt.%. It is preferably above 45 wt.%, and more preferably above 50 wt.%, based on the total weight of the carbonaceous material particles. On the other hand, it is typically at most 90 wt.%, and often at most 80 wt.%, based on the total weight of the carbonaceous material particles. It may be up to 70 wt.% or even up to 60 wt.%, based on the total weight of the carbonaceous material particles. Certain useful ranges for the carbon content of the carbonaceous material particles useful in the present invention are from either about 40 wt.% to about 80 wt.%, or from about 45 wt.% to about 75 wt.%, based on the total weight of the carbonaceous material particles. The carbon content of these carbonaceous material particles can be determined by any method known to the skilled person. For example, the carbon content may be determined by: drying the carbonaceous material particles in an oven at 100 ℃ for 12h (to remove water and other volatiles), then holding the dried particles in a dryer (to avoid water absorption), then burning the carbonaceous material particles in a combustion furnace under conditions that convert substantially all (when not all) of the carbon content of the carbonaceous material particles to carbon dioxide, then quantifying the C content by infrared detection (by CO formed via combustion)₂)。

The carbon-containing material includes, by way of illustration and not limitation, coal, coke, graphite, charcoal, bio-coal such as charcoal or roasted biomass, especially roasted wood and the like. In general, any carbonaceous fuel may be used as the solid carbonaceous material in the present invention.

In a preferred embodiment, the carbonaceous material is coal. By way of illustration, anthracite, semi-anthracite, medium and high volatile bituminous, sub-bituminous, and lignite may be advantageously used to practice the present invention.

The coal used in the present invention may be obtained in dry or wet form and mixed with a fluid to form a coal-fluid mixture.

Considering the manner in which coal is broken down during milling, the coal particles will have irregular shapes, however, these shapes have a main body (or maximum side-to-side thickness) such that discrete particles below the screen size will pass through a given mesh of the screen. The size of the discrete particles may be expressed in terms of sphere diameters comprised between 1 μm and 5000 μm; coal particles from a sample of coal or coal-water slurry will pass through the sphere diameter. For particles finer than 10 μm, the size of the particles may be determined by means of a sieve, or a settler, or a Scanning Electron Microscope (SEM), or the like.

In certain embodiments, the particle size values and size distributions of the particles are in accordance with ISO 13320: the principles and ground rules listed in 2009(E), as measured by laser diffraction by dry dispersion.

In practice, the analysis is preferably carried out using a Helos H1302 laser diffraction sensor (Sympatec, n.patach, germany).

The detector focal length is chosen such that its passband covers the size range of these carbonaceous material particles to be analyzed.

For example, an R4 detector (0.5 μm to 350 μm) is particularly well suited when analyzing milled torrefied biomass.

These carbonaceous material particles were dispersed under pressure in a stream of dry nitrogen using a dry dispersion unit (Rodos, new pataks, germany).

The optimum operating conditions were experimentally sought to obtain a good dispersion of particles without breaking in the eductor. In practice, when analyzing carbonaceous material particles in the form of ground torrefied biomass, the nitrogen pressure is about 100kPa (1 bar) and the low pressure (depression) represents about 4kPa (40 mbar).

A vibratory trough is used to feed the carbonaceous material particles. The feed rate was adjusted so as to obtain an optical concentration between 2% and 10%.

In practice, the total mass of the sample containing these carbonaceous material particles to be analyzed ranges from about 1g to about 10g, preferably about 5 g.

Laser diffraction data were acquired and analyzed using windows 5 software (napatch, germany).

In some embodiments, the carbonaceous solid material is coke. Coke is a solid, porous, refractory material that remains after the carbonization of coal, pitch, petroleum residues, and certain other carbonaceous materials. Various cokes, other than those derived from coal, are generally identified by: the word is prefixed to indicate the source, e.g., "petroleum coke". To illustrate the method of making the coke, a prefix, e.g., "honeycomb furnace coke," is also often used.

By way of illustration and not limitation, petroleum coke may be used in the present invention. There are at least two types of petroleum coke: delayed coke, and fluidized coke. The delayed coke generally contains from about 8 to about 18 weight percent volatiles, has a grindability index of from about 40 to about 60, and has a true density of from about 1.28 to about 1.42 grams/milliliter. The fluidized coke generally contains from about 3.7 to about 7 weight percent volatiles, has a grindability index of from about 20 to about 30, and has a true density of from about 1.5 to about 1.6 grams/ml.

Other carbonaceous materials that may be used in the present invention include, for example, high temperature coke, foundry coke, low temperature coke, medium temperature coke, pitch coke, char, charcoal, solvent refined coal, and mixtures of one or more of the carbonaceous materials with coal and/or petroleum coke. Mixtures of coal and petroleum coke can be used in the present invention.

Most preferably, the carbonaceous material according to the invention may also be a biological coal, such as a torrefied biomass, such as a torrefied wood. Bio-coal is a solid fuel made from biomass by heating it in an inert atmosphere. The result is a product called charcoal, or (if the process temperature is mild), a fired wood. Indeed, biomass can be converted by heating in a low oxygen environment through a process called torrefaction into a hydrophobic, corrosion resistant material that can be used as a fuel (e.g., as a coal fuel substitute, feedstock for entrained flow gasification, or other fuel), soil additive, long-term carbon storage mechanism, or for other suitable uses. In particular, the torrefied biomass can be used in existing fuel-fired power plants (e.g., coal-fired power plants), thereby facilitating the use of renewable fuels for power generation with existing fuel-fired infrastructure.

Torrefaction of biomass can be described as a mild form of pyrolysis at temperatures typically ranging between 230 ℃ and 320 ℃. During torrefaction, water present in the biomass may evaporate and biopolymers of the biomass, such as cellulose, hemicellulose and lignin, may partially decompose, giving off various types of volatile organic compounds called "torrefaction gases" (torgas), resulting in a loss of mass typically between about 30% and about 40% and a loss of chemical energy between about 10% and about 20% in the gas phase. Calcination results in energy densification, producing a solid product with a lower moisture content and a higher energy content than untreated biomass. The resulting product may be a solid, dry, dark brown or blackened material referred to as "fired wood", "fired biomass", "bio-coal" or "renewable coal replacement fuel" ("RCRF").

A preferred example of carbonaceous material particles is calcined wood particles. The inventors have shown that very good results are obtained when preparing a liquid biofuel as described herein with the calcined wood particles. Notably, it has been shown that the calcined wood particles suspended in the liquid biodiesel composition are readily dispersible, which further increases the processability, including pumpability, of the liquid biofuel.

Without wishing to be bound by any particular theory, the inventors believe that the calcined wood particles are notably imparted with better dispersible properties because they have a hydrophobic surface compared to other carbonaceous material particles.

Unless otherwise stated in this specification, the weight of carbonaceous material is herein on a moisture free or "dry basis". Thus, as used herein, the term "dry basis" refers to a carbonaceous material that is substantially free of a carrier liquid. The carbonaceous material is considered dry after it has been air dried by exposure to air at a temperature of at least 20 ℃ and a relative humidity of less than 50% for at least 24 hours.

These carbonaceous material particles of the present invention are referred to as solid particles; it refers to particles that are in a solid state rather than a liquid or molten state. However, as can be appreciated by those skilled in the art, the solid particles may have varying degrees of hardness depending on factors such as, for example, the atmosphere to which they are exposed.

These carbonaceous material particles preferably provide an average diameter D ranging from 0.1 μm to 200 μm₅₀。

In some embodiments, the carbonaceous material particles have a D ranging from 1 μ M to 50 μ M, and most preferably ranging from 8 μ M to 25 μ M₅₀A defined size distribution.

In some embodiments, these carbonaceous material particles preferably provide the following size distribution:

-D₁₀comprised between 1 and 50 μm,

-D₅₀comprised between 0.1 and 100 μm, preferably between 3 and 20 μm, and

-D₉₀including between 50 and 500 μm.

Such an average diameter can be obtained by wet or dry grinding (which can be carried out in batch or continuous mode), in particular in a grinding machine such as a roller mill. A roller mill is any horizontally mounted cylindrical mill that tumbles its contents while rotating. The preferred roller mill for use in the present invention is a ball mill.

The particle size distribution and in particular the mean diameter D50 of the carbonaceous material can be determined by using a laser diffraction sensor, a settler or a Scanning Electron Microscope (SEM).

In some embodiments, the liquid biofuel, the carbonaceous material particle content is at least 10% w/w of said biofuel, preferably at least 20% w/w of said biofuel, and most preferably at least 30% w/w of said biofuel.

As shown in this example, a liquid biofuel can be prepared that contains carbonaceous material particles in an amount greater than 50% w/w, while maintaining the dispersibility of the particles and maintaining the rheological properties of the shear-thinning liquid.

As intended herein, a carbonaceous material particle content of at least 10% w/w includes at least 15% w/w, 20% w/w, 25% w/w, 30% w/w, 35% w/w, 40% w/w, 45% w/w, 50% w/w, 55% w/w, 60% w/w, and 60% w/w, based on the total weight of the liquid biofuel.

The carbonaceous material particle content of the liquid biofuel is preferably less than 80% w/w in order to avoid the production of a biofuel liquid having too high a viscosity.

In some embodiments, a liquid biofuel as described herein may comprise from 10 to 80% by weight of carbonaceous material particles, including from 40 to 60% by weight.

Additional features of liquid biofuels

In some embodiments, a liquid biofuel as described herein further comprises water, preferably in an amount of 0.5% w/w or more and 20% w/w or less, based on the total weight of the liquid biofuel.

As used herein, an amount of 0.5% w/w or more of water includes at least 0.5% w/w, 1% w/w, 2% w/w, 3% w/w, 4% w/w, 5% w/w, 6% w/w, 7% w/w, 8% w/w, 9% w/w, 10% w/w, 11% w/w, 12% w/w, 13% w/w, 14% w/w, 15% w/w, 16% w/w, 17% w/w, 18% w/w and 19% w/w based on the total weight of the liquid biofuel.

In embodiments of liquid biofuels where the biofuel comprises water, the liquid biofuel may be in the form of an oil-in-water (O/W) emulsion. Such an O/W emulsion can be prepared by simply mixing the liquid composition comprising (i) a suspension of carbonaceous material particles in a liquid biodiesel composition and (ii) water.

The inventors have shown that in embodiments where the liquid biofuel consists of a W/O emulsion, the carbonaceous material particles (e.g. calcined wood particles) are located in the continuous phase. In the embodiments, the inventors have shown that the carbonaceous material particles (e.g. calcined wood particles) are captured between droplets in the continuous phase, which prevents them from settling. At the same time, the carbonaceous material particles may act as an emulsifier, preventing coalescence of the droplets.

Without wishing to be bound by any particular theory, the inventors believe that O/W emulsions are successfully prepared when the liquid biofuel as described herein comprises water because non-esterified or de-esterified fatty acid and/or alcohol molecules may be present, which act as polar molecules with a surfactant effect.

These results explain why there is no requirement for added emulsifiers, added dispersants, added humectant agents, added wetting agents, added surfactant agents, nor viscosity control agents to obtain a suitable liquid biofuel as described herein.

Thus, in some preferred embodiments, the liquid biofuel is free, substantially free, or contains less than 0.1 wt.% of any non-ionic emulsifier, such as alkoxylated fatty carboxylic acids, alkoxylated fatty alcohols, alkoxylated octylphenols or nonylphenols, alkoxylated fatty amines, alkoxylated fatty amides (where "fat" used wherever here generally indicates C), based on the total weight of the liquid biofuel₈-C₂₄Compound) or mixtures thereof.

In some other preferred embodiments, the liquid biofuel is free of, substantially free of, or contains a total amount based on the liquid biofuelLess than 0.1 wt.% by weight of any ionic emulsifier, such as C₈-C₂₄Sodium alkyl sulfate, sodium dodecylbenzene sulfonate, sodium dioctyl sulfosuccinate, ammonium myristate, cetyl pyridinium chloride, alkali metal salts of naphthalene sulfonic acid, alkali metal lignosulfonate, and the like.

In still other preferred embodiments, the liquid biofuel is free, substantially free, or contains less than 0.1 wt.% of any dispersant, such as polyvinyl alcohol (notably commercially available as a "POVAL" dispersant) having a hydrolysis rate of from about 25% to about 100%, based on the total weight of the liquid biofuel.

In still other preferred embodiments, the liquid biofuel is free of, substantially free of, or contains less than 0.1 wt.% of any humectant agent, based on the total weight of the liquid biofuel.

In still other preferred embodiments, the liquid biofuel is free of, substantially free of, or contains less than 0.1 wt.% of any wetting agent, based on the total weight of the liquid biofuel.

In still other preferred embodiments, the liquid biofuel is free of, substantially free of, or contains less than 0.1 wt.% of any surfactant agent, based on the total weight of the liquid biofuel.

In still other preferred embodiments, the liquid biofuel is free of, substantially free of, or contains less than 0.1 wt.% of any viscosity agent, such as clay powders or gels, hydrogenated castor oil, and mixtures thereof, based on the total weight of the liquid biofuel.

In some particularly surprising embodiments of a liquid biofuel as described herein, the liquid biofuel contains less than 1000ppm of any added compounds capable of performing an emulsifying or stabilizing effect, based on the total weight of the biofuel. In particular, the liquid biofuel may be substantially free or may be free of any added compounds capable of performing an emulsifying or stabilizing effect.

In some other particularly surprising embodiments of a liquid biofuel as described herein, the liquid biofuel does not contain any added emulsifier, any added surfactant agent, any added dispersant, any added humectant agent, any added wetting agent, nor any added rheological additive. As used herein, the term "surfactant" refers to an amphiphilic compound that includes a hydrophilic portion and a hydrophobic portion, and when present in water, reduces the surface tension of the water.

In some embodiments, the liquid biofuels as described herein may also include one or several possible additives generally known in the art, such as, for example, antioxidant agents, Cold Flow Improvers (CFI), corrosion inhibitors, foam inhibitors, and biocidal preservatives.

Characteristics of the final suspension

A liquid biofuel as described herein may provide a viscosity comprised between 0.1 and 10000 pa.s at a temperature of 70 ℃.

Further, it is also shown in the examples that when a liquid biofuel as described herein is subjected to an increased shear rate value, its viscosity decreases. These rheological properties of the liquid biofuel show that the liquid biofuel is easily processable and in particular easily pumpable.

The rheological properties of these suspensions can be measured using a rheometer under controlled shear rate conditions.

Production of liquid biofuels

The liquid biofuel as described herein can be obtained by several known methods, notably by simply mixing the carbonaceous material particles in the liquid biodiesel composition.

It is in particular possible to produce the suspension by milling under wet conditions, which can be carried out in batch or continuous mode. It is entirely possible to add the carbonaceous material, the liquid phase and the additives together prior to the milling operation in order to provide a composition having exactly the desired concentration, or alternatively the carbonaceous material content may be deliberately set at a low level during milling and subsequently increased to the desired level by a dewatering process. The milling process described herein is presented by way of example and is not intended to be limiting as there are many methods of milling carbonaceous material into a composition, including dry processes using a ball mill, or any of a number of other mills (such as those cited above). If any dry milling method is used, it may be preferred to perform a washing step after dry milling to avoid dehydration and drying procedures prior to milling.

It is also possible to go to wet or dry milling of the carbonaceous material to achieve the desired size distribution and, in particular, subsequently blending the carbonaceous material with the liquid phase and the additives with classical stirring/reversing blades.

The invention also relates to a composition having D ranging from 0.1 μm to 200 μm₅₀Use of the carbonaceous material particles of (a) for the preparation of a liquid biodiesel-based biofuel.

The invention also relates to a method for generating electricity comprising combusting a liquid biofuel as described herein.

The following examples are included to illustrate embodiments of the invention. It goes without saying that the invention is not limited to these described examples.

Examples of the invention

The compounds used in the examples below are as follows:

calcined wood chips: 28 GJ/ton, 10% RH, raw sources, Malaysian biofuel based on palm oil from New Biomass Energy LLC

Specified additives

Example 1: preparation of fired wood particles

The calcined wood chips obtained by the calciner (torrefactor) process and having a cm size are first ground by a dry grinding process to obtain a particle size of 300 μm to 1 mm. This powder was then dry milled through a Retsch ZM200 dry mill with the following characteristics: grid 120 μm, speed 18000rpm, 25 deg.C, nitrogen purge, 80g each batch in 10 min; in order to obtain the following particle size distribution centered at 25 μm:

D₁₀＝6μm

D₅₀＝23μm

D₉₀＝60μm

these size distributions were measured with a neopataxy laser diffraction sensor.

Example 2: liquid biofuel production

The slurry was prepared by mixing 70% w/w liquid biodiesel (Malaysian biodiesel) and 30% w/w particles of calcined wood.

The liquid biofuel based on Malaysian biodiesel without additives was stable during visual inspection over 2 days and 2 weeks periods.

Example 3: liquid biofuel emulsion preparation

In example 3, two liquid biodiesel compositions were used for the preparation of liquid biofuels, (i) the Malaysian biofuel used in example 2 and (ii) LOF biodiesel comprising a mixture of palm oil esters, palm oil stearin, palm oil mill sludge (POME) and palm oil methyl ester.

Two biofuels (Malaysian and LOF) with different water and calcined wood particle (TWP) content were used. The results show that for up to 40% w/w of the fired wood particles, 10% water is able to stabilize the slurry. Further, the addition of water increases the viscosity of the liquid biofuel.

The following liquid biofuels based on Malaysian biodiesel were prepared: (i) the method comprises the following steps 50%/TWP 30%/water 20%, (ii) Malaysian biodiesel 50%/TWP 40%/water 20%,

the following liquid biofuels based on LOF biodiesel were prepared at 2 weeks: (i) 50%/TWP 40%/water 10%, (ii) LOF biodiesel 50%/TWP 30%/water 20% (left to right).

The viscosity of the water/biodiesel/TWP biofuel is shown in figure 1. The shear thinning behavior of the produced liquid biofuel is quite apparent. As more water is added, the viscosity decreases.

As shown in fig. 1, the Malaysian biodiesel-based biofuel has a higher viscosity than the LOF biodiesel-based biofuel at all shear rate values.

This method was also tested on liquid biofuels made from Colza biodiesel.

The following liquid biofuels based on Colza biodiesel were prepared at 48 h: 0%/TWP 30%/water 0%, Colza biodiesel 50%/TWP 40%/water 10%, Colza biodiesel 50%/TWP 30%/water 20% and Colza biodiesel 60%/TWP 30%/water 10% (left to right).

Using a liquid biofuel comprising a suspension of calcined wood particles suspended in Colza biodiesel in the presence of water, the same rheological behaviour as using Malaysian biodiesel was observed. The addition of water stabilized the slurry, for which no settling of the fired wood particles was observed on day 2.

Claims

1. A liquid biofuel comprising D having a range from 0.1 μm to 200 μm suspended in a liquid biodiesel composition₅₀Wherein the liquid biodiesel is produced by chemically reacting a lipid contained in a vegetable oil or an animal fat with methanol, ethanol or propanol.

2. The liquid biofuel of claim 1, wherein the lipid comprises triglycerides, and wherein reacting the lipid with methanol comprises decomposing the glycerol of triglycerides consisting of three long chain fatty acid molecules connected by glycerol molecules using sodium hydroxide or potassium hydroxide as a catalyst, each of the three fatty acid chains combining with a methanol molecule to produce a monoalkyl ester.

3. The liquid biofuel according to claim 1 or 2, wherein the liquid biofuel is Fatty Acid Methyl Ester (FAME).

4. Liquid biofuel according to any one of claims 1 to 3, wherein the Fatty Acid Methyl Esters (FAME) comply with the International Standard EN 14214.

5. The liquid biofuel according to any one of claims 1 to 4, wherein the liquid biofuel comprises at most 0.2% by weight of triglycerides based on the total weight of the starting liquid biofuel.

6. Liquid biofuel according to any one of claims 1 to 5, wherein the content of the carbonaceous material particles is at least 10% w/w of the biofuel.

7. The liquid biofuel of any one of claims 1 to 6, wherein the carbonaceous material particles have a D of from 1 μm to 50 μm₅₀The size distribution of (a).

8. The liquid biofuel of claim 7, wherein the carbonaceous material particles have a D of from 8 to 25 μm₅₀The size distribution of (a).

9. The liquid biofuel of any one of claims 1 to 8, wherein the carbonaceous material particles are selected from the group of: plant biomass, coal, coke, graphite, charcoal, bio-coal, and combinations thereof.

10. The liquid biofuel of claim 9, wherein the carbonaceous material particles comprise torrefied biomass.

11. The liquid biofuel of claim 10, wherein the carbonaceous material particles comprise fired wood particles.

12. The liquid biofuel of claim 9, wherein the carbonaceous material particles are bio-coal.

13. The liquid biofuel of claim 9, wherein the carbonaceous material particles are coal.

14. The liquid biofuel of claim 13, wherein the coal is selected from the group consisting of: anthracite, semi-anthracite, medium and high volatile bituminous, sub-bituminous, and lignite.

15. The liquid biofuel of any one of the preceding claims, further comprising water in an amount of from 0.5% w/w to 25% w/w.

16. The liquid biofuel according to any one of the preceding claims, wherein it does not comprise any added emulsifier or any surfactant compound.

17. The liquid biofuel of claim 16 wherein the liquid biodiesel composition comprises a biodiesel composition derived from waste cooking oil.

18. The liquid biofuel of claim 16, wherein the liquid biodiesel composition comprises a biodiesel composition derived from palm stearin, a biodiesel composition derived from palm oil methyl ester or a biodiesel composition derived from waste cooking oil.