Patent Application
20250043205
The present invention relates to fuels. More specifically, the present invention is related to biofuel oily suspensions that employ solid biocarbon in their composition.
Internal combustion engines are widely used in industries covering segments such as machine movement, cogeneration, and transport, covering a wide range of capacities. They are applied in different modes of transport, in large, medium, and small machines, and in the naval, railway, and road sectors. Compression-burning internal combustion engines, commonly called diesel engines in honor of their inventor, Rudolph Diesel, are of great relevance.
Liquid fossil fuels from petroleum distillation are usually used in compression internal combustion engines. In general, for large engines, higher viscosity fuels called heavy fuel oil (HFO—Heavy Fuel Oil or HFOLS—Heavy Fuel Oil Low Sulphur), normally called bunker oil, are used, and for medium and small engines they are used lower viscosity fuels were used, called diesel oil and gas oil.
Although the fossil fuels mentioned above are currently in widespread use, the world is rapidly moving towards changing the energy matrix, which will imply an agenda of bold commitments towards an economy with zero carbon emissions. To achieve this goal of reducing Greenhouse Gases—GHGs in the transport sector, countries will have to simultaneously adopt a set of measures. Biofuels are among the main protagonists in reducing carbon emissions in the transport sector in several countries.
As an example, the European Union (EU) recently launched a bold plan to reduce GGE emissions by at least 55% by 2030, known as the “Fit for 55” Package, which will contribute so that member countries can meet the objective of a carbon neutral EU by 2050, under what is established by the Paris Agreement. The plan includes the transport sectors, including aviation and maritime—currently responsible for almost 40% of all emissions. The commitment of these modes to the goals assumed will be fundamental for the European continent to achieve a rapid reduction in CO2 emissions.
Additionally, it is proposed to ban the use of conventional diesel, gasoline, gas, or even hybrid technology, in new vehicles by 2035, creating a space for electric or biodiesel-powered vehicles.
In this scenario, which is gradually spreading throughout the world, biodiesel plays a very important role in providing an energy alternative to entirely fossil fuel, as it generally contains raw materials of vegetable origin in its composition, such as soybean oils, cotton, castor beans, sunflower, babassu, peanuts, palm oil, etc.
In addition to the conventional biodiesel composition previously described, recent studies show the possibility of using coal, especially of mineral origin, in micronized form (particle size less than 50 μm) mixed with a liquid, such as water, forming an aqueous suspension.
However, the use of micronized mineral coal for the manufacture of aqueous suspensions still faces several technical barriers for its practical application, as its physical-chemical properties (calorific power, viscosity, and inorganic content) differ from the fuels used today, which requires adaptations to the engines currently on the market.
Furthermore, solid coal has a hydrophobic chemical nature, which makes its stability difficult when mixed with water. Another relevant point is that experimental results show that the calorific value of the aqueous coal suspension, and therefore, the energy density, is considerably lower than that of fuels currently on the market.
Finally, the presence of inorganics in the composition of micronized carbons used in state-of-the-art biofuels commonly generate problems of scale and wear due to abrasion of internal engine components.
In the context of seeking sustainability in production processes, biomass pyrolysis technology has been recognized by the technical and scientific community as a powerful tool for transforming biomass into new products such as charcoal, synthesis gas (syngas) and liquids such as tar and pyroligneous extract. Precisely to characterize the biomass pyrolysis process carried out rigorously under aspects of operational safety and respect for the environment, charcoal began to receive other names in the literature such as biochar or biocarbon. This last term is what will be adopted in this invention to designate the solid product obtained from biomass pyrolysis.
The document US2016137939A1 reveals a liquid fuel derived from processed biomass with extremely low water content and suitable for use in diesel engines or as an additive to petroleum-based fuels, or which can be used as a substitute for petroleum or coal slurry in those uses where a fuel of lower cost reduces emission is desired.
The document “Analysis of Micronized Charcoal for Use in a Liquid Fuel Slurry” from 2016 reveals the use of yellow poplar (Liriodendron tulipifera) as woody biomass for the production of charcoal for use in a liquid fuel slurry. The charcoal produced from this biomass resulted in a highly porous structure similar to the original material. Micronized particles were produced from this coal using a multi-step milling process and verified using a scanning electron microscope and a laser diffraction system.
The 2015 document “Development of a charcoal slurry for compression ignition internal combustion mechanisms” deals with a solid biofuel, charcoal, in the form of a liquid paste for use in a compression ignition IC engine. Charcoal pastes were produced by adding micronized charcoal to mixtures of biodiesel and diesel oil. The charcoal was micronized using a multi-step grinding process using charcoal produced from virgin materials and wood waste. The particles were analyzed using various techniques to determine the physical and chemical properties of the charcoal used in the production of a paste. The coal slurry has been successfully tested on a diesel engine platform.
The 1984 document “Diesel Engine Injection and Combustion of Slurries of Coal Charcoal, and Coke in Diesel Fuel” reveals fuels contaminated with solids and evaluated for their relative potential as a fuel for diesel engines. Thirteen test fuels with different solids concentrations were formulated using eight different materials. The injection and atomization characteristics (transient diesel sprays) of the test fuels were examined in a spray pump in which a nitrogen atmosphere was maintained at high pressure and temperature, 4.2 MPa and 480° C., respectively. The diagnosis of the sprays included high-speed film and high-resolution photographs. The pastes were also tested on a single-cylinder CLR engine in direct injection and pre-chamber configurations. The data included normal performance parameters as well as heat release rates and emissions.
The 2020 document “Char-Diesel slurry fuels for microgeneration: emission characteristics and engine performance” teaches about the use of so-called “fuel pastes” produced by mixing micrometric particles of carbonaceous material in diesel and evaluates whether these “fuel pastes” can be used on a standard diesel engine generator with minimal modifications. Two types of micronized carbons were added to diesel, produced by pyrolysis or hydrothermal carbonization of biomass.
The 2014 document “Development of a Charcoal Slurry for Compression Ignition Internal Combustion Engines” deals with the thermal pathway that uses heat to break down biomass into usable compounds and/or energy. Charcoal is one of the usable compounds produced and is currently used throughout the world as a solid fuel for heating and cooking, where the use of charcoal in the form of liquid paste has been investigated as a renewable alternative to charcoal and oil pastes diesel in compression ignition IC engines. The charcoal was successfully micronized using a multi-step grinding process. Different coal sources were used and analyzed to develop coal slurries that were successfully tested on a diesel engine platform. Virgin coal was produced under controlled conditions and analyzed to calculate energy density for comparison of coal slurries with other liquid fuels.
The document “Combustion characteristics of a charcoal slurry in a direct injection diesel engine and the impact on the injection system performance” from 2011 reveals the use of renewable biomass-diesel coal pastes and their use as alternative fuels for combustion in diesel generating plants, investigating the formulation, emulsification, sprays, combustion, injection system operation, and subsequent wear with coal-diesel pastes.
The 1977 document “An Experimental Investigation of a Coal-Slurry Fueled Diesel Engine” reveals a test in which a 1360 cc single-cylinder diesel engine was operated with a slurry of 15 percent by weight of solvent-refined coal-slurry fuel aviation. The coal was pulverized to a nominal size of 2 micrometers.
The 2018 document “An assessment of the viability of alternatives to biodiesel transport fuels” presents an economic feasibility study of using algae and biochar deposition strategies to offset the carbon emission of conventional fossil-derived transport fuels. Economic viability is quantified based on the final price of decarbonized fossil diesel, which must be lower than or equal to the price of biodiesel considered the next best alternative. The extra costs associated with carbon capture/offset via algae and biochar are estimated for the most typical scenarios using the developed economic models. Furthermore, global sensitivity analyzes based on high-dimensional model representation (HDMR) are performed to quantify the influence of key model parameters on overall costs.
The proposed invention solves the prior art problems described above simply and efficiently.
The present invention's first objective is to provide a biocarbon-based biofuel oily suspension better adapted to compression internal combustion engines currently on the market, dispensing with major adaptations to them.
The present invention has as a second objective to provide an oily biofuel suspension based on highly sustainable biocarbon and with calorific value, energy density and viscosity compared to fuels currently present on the market.
To achieve the objectives described above, the present invention provides a biofuel oily suspension, comprising 5 to 50% by mass of micronized biocarbon and 50 to 95% by mass of suspension base liquid.
The invention also provides a process for manufacturing the aforementioned biofuel oily suspension comprising the steps of (i) micronizing biocarbon to a maximum diameter of 50 μm and (ii) mixing 5 to 50% by mass of micronized biocarbon to 50 to 95% in mass of suspension base liquid.
The detailed description presented below makes reference to the attached FIGURE and their respective reference numbers.
Preliminarily, it should be noted that the following description will start from preferred embodiments of the invention. As will be evident to anyone skilled in the art, however, the invention is not limited to these particular embodiments.
The present invention therefore provides an oily biofuel suspension, comprising 5 to 50% by mass of micronized biocarbon and 50 to 95% by mass of the liquid base of the suspension. For the purposes of this description, micronized biocarbon is any charcoal of vegetable origin, produced according to sustainable standards, with a maximum diameter of 50 μm. Preferably, this biocarbon has a low inorganic content (less than 1%).
Preferably, the liquid base of the aforementioned suspension is at least one of (i) bunker oil (also known as HFO—Heavy Fuel Oil), (ii) marine diesel oil (MDO—Marine Diesel Oil or MGO—Marine Gasoil), (iii) hydrotreated vegetable oil (HVO—Hydrotreated Vegetable Oil), (iv) hydrotreated pyrolysis oil (HPO—Hydrotreated Pyrolysis Oil), and (v) vegetable tar (also called PO—Oil of Pyrolysis or Pyrolysis Oil).
More preferably, the liquid base of the suspension used in the present invention may be a mixture of at least two of the above-mentioned oils in suitable proportions to generate a biofuel with viscosity and energy density equivalent to fuel oils found on the market.
In the first embodiment of the present invention, the following composition is used:
In this first embodiment, biocarbon is mixed with bunker oil. The engineering of large combustion engines is already prepared to operate with a viscosity typical of bunker oil. Naturally, as solid biocarbon particles are introduced into the suspension, its viscosity tends to increase. Another oily base, diesel oil or gas oil, is then introduced to adjust the viscosity of the suspension and return it to values close to the original viscosity of the bunker. This is a suspension characterized by the partial replacement of fossil fuel (bunker) with green fuel (biocarbon). It is a highly optimized suspension in terms of technical (burning) and logistical aspects since the introduction of biocarbon can be carried out in different proportions and implemented gradually.
In a second embodiment of the present invention, 100% sustainable, the following composition is used:
In this second embodiment, the biocarbon is mixed with a completely green oily base, which may be HVO (Hydrotreated Vegetable Oil) or vegetable tar (PO Pyrolysis Oil) or a mixture of these components. This suspension is characterized by lower viscosity compared to the bunker and, in this case, there is a suspension composed only of sustainable products, that is, of renewable origin.
In a third embodiment of the present invention, also 100% sustainable, the following composition is used:
In this third embodiment, the suspension is composed of biocarbon and the oily base HPO (Hydrotreated Pyrolysis Oil) and, like the second embodiment, is completely sustainable.
The three aforementioned embodiments have one characteristic in common: the use of micronized biocarbon in the composition. Aiming for suspensions that result in the lowest level of wear due to abrasion in diesel engines, it is preferable to produce biocarbon from biomass with low ash content, such as eucalyptus, preferably without the bark, which has a higher inorganic content compared to the wood core itself.
The present invention also provides a process for manufacturing the biofuel oily suspension described above, comprising the steps of (i) micronizing biocarbon to a maximum diameter of 50 μm and (ii) mixing 5 to 50% by mass of micronized biocarbon to 50 to 95% by mass of liquid suspension base.
The present invention refers to an oily biofuel suspension whose composition contains a portion of biocarbon from the carbonization of biomass in micronized form (particles smaller than 50 μm). The presence of biocarbon provides advantages in the ecological aspect, such as a reduction in greenhouse gas and SOx emissions, in marketing aspects, by bringing cost reduction through the use of cheaper fuel raw materials and in technical aspects.
The main technical advantages arise from the catalytic effects due to the presence of solid biocarbon particles in the reacting atmosphere, inside the engine's combustion chamber.
Firstly, the internal surface area associated with porosity, as well as the external surface area of biocarbon particles, favors the process of physical adsorption of oxygen molecules and other liquid fuels, promoting chemical interaction between them, which characterizes a catalytic effect in the process of combustion. More specifically, biocarbon is a product with a high concentration of carbon, typically greater than 80%, depending on the raw material and operational conditions in which it is produced. It is, therefore, a friable and porous product, and these pores can be closed or open. Associated with the degree of micronization, the external specific surface area of the particles is generated and associated with porosity, the internal specific surface area of the particles is generated. Both the external and internal specific surface area contribute to the phenomenon of heterogeneous catalysis during the combustion process. This effect is illustrated in
Additionally, the catalytic effect of the injection of potassium salts in the burning of solid, liquid and gaseous fuels is known. It is also known from the relevant literature that, during the biomass carbonization process, the migration of inorganic elements present in the precursor biomass occurs, forming pockets of SiO2 and KCl crystals on the surface of the biocarbon particle. Biomass and its respective biocarbon contain micronutrients in their composition, including potassium salts. In this way, the heterogeneous suspension containing biocarbon is an intrinsic way of seeking this catalytic action of potassium in the combustion process. This effect, where potassium reduces the activation energy and catalyzes the reaction of oxygen with the carbon surface of the biocarbon itself, is illustrated in
Optionally, the present invention also provides for the introduction of additives into the biocarbon-based biofuel oily suspension, such as surfactant agents, to improve the stabilization of the solution and its handling, transport, and storage properties. Additives can be used in small proportions, typically less than 5%.
In addition to the innovative effects listed above, the following advantages are observed in the biofuel of the present invention:
The biofuel of the present invention has its viscosity, calorific value, and energy density adjustable to its applications. This way, it can be adjusted to replace any types of diesel oils currently on the market. By way of example, the present invention can be used very efficiently to replace bunker oil for applications in low-speed engines, such as marine engines. However, its application is not limited to this specific application, and can also be used in engines used in rail, road, air transport, machine movement, and cogeneration.
Thus, as explained above, the present invention provides a biofuel oily suspension better adapted to diesel engines currently on the market, dispensing with major adaptations to them. Furthermore, the biofuel oily suspension of the present invention is highly sustainable and has a calorific value, energy density and viscosity compared to fuels currently on the market.
Numerous variations affecting the scope of protection of this order are permitted. In this way, the fact is reinforced that the present invention is not limited to the particular configurations/embodiments described above.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1020220061432 | Mar 2022 | BR | national |
This application is a Continuation of PCT Patent Application No. PCT/BR2023/050054 having International filing date of Feb. 15, 2023, which claims the benefit of priority of Brazilian patent application Ser. No. 1020220061432 filed on Mar. 30, 2022. The contents of the above applications are all incorporated by reference as if fully set forth herein in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/BR2023/050054 | Feb 2023 | WO |
| Child | 18901042 | US |
