Fuel mixture comprising marine fuel and tall oil

Abstract

Fuel mixture comprising: (a) from 80% by weight to 99.99% by weight, preferably from 85% by weight to 99.95% by weight, of marine fuel; (b) from 0.01% by weight to 20% by weight, preferably from 0.05% by weight to 15% by weight, of tall oil; the sum of (a) + (b) being equal to 100; wherein said marine fuel has the following characteristics: - a density, at 15°C, comprised between 890 kg / nr and 1010 kg / m3, preferably comprised between 910 kg / m3 and 991 kg / m3; - a kinematic viscosity, at 50°C, comprised between 6 mm2 / s and 700 mm2 / s, preferably comprised between 20 mm2 / s and 500 mm2 / s; - a total quantity of post-hot filtration sediments (TSA - "Total Sediment Aged") less than or equal to 0.1% m / m; - an acidity (TAN - "Total Acid Number") less than or equal to 2.5 mg KOH / g, preferably comprised between 0.05 mg KOH / g and 2.4 mg KOH / g; - a Conradson carbon residue (CCR) less than or equal to 20% m / m. Said fuel mixture can advantageously be used, as such, or in a mixture with other renewable or fossil marine fuels, in combustion engines for ships.

Description

[0001] FUEL MIXTURE COMPRISING MARINE FUEL AND TALL OIL

[0002] DESCRIPTION

[0003] The present invention relates to a fuel mixture comprising marine fuel oil and tall oil.

[0004] More specifically, the present invention relates to a fuel mixture comprising marine fuel oil and tall oil, in specific quantities, said marine fuel having specific characteristics.

[0005] Said fuel mixture can advantageously be used, as such, or in a mixture with other renewable or fossil marine fuels, in combustion engines for ships.

[0006] The present invention also relates to the use of said fuel mixture, as such, or in a mixture with other renewable or fossil marine fuels, in combustion engines for ships.

[0007] There are two basic types of marine fuel: distillate-based marine fuel, also known as marine gas oil [“Marine Gas Oil” (MGO) or “Marine Diesel Oil” (MDO)]; and residual marine fuel [“Residual Marine Fuel Oil” (RMFO)], also known as heavy marine fuel oil [“Heavy Marine Fuel Oil” (HMFO)].

[0008] Large ocean-going vessels have relied on residual marine fuel [“Residual Marine Fuel Oil” (RMFO) or “Heavy Marine Fuel Oil” (HMFO)] to power large combustion engines for over 50 years.

[0009] However, the high conten t of heavy substances, and in particular of aromatic- based substances (for example, polynuclear aromatic compounds, asphaltenes), in residual marine fuel [“Residual Marine Fuel Oil” (RMFO) or “Heavy Marine Fuel Oil” (HMFO)] can be critical for optimal combustion in the combustion engines in which it is used. For this reason, it is important to evaluate the CCR parameter (Conrandson carbon residue) representative of the tendency to form coke. Specifically, the CCR parameter indicates the formation of carbon deposits that are formed on the injectors, pistons and piston rings, which could give rise to tribological phenomena (abrasive wear) and to a delayed combustion (increased flame area in the cylinder), with a reduction in the lubricating power exerted by the oil. Reducing this parameter therefore means not only improving fuel combustion, but also extending the life of the engine itself. It is known both to add tall oil to fuels and to use tall oil as a fuel.

[0010] For example. International Patent Application WO 2013 / 098524 relates to the use of a liquid fuel derived from biomass as an additive for stabilising a fuel composition comprising a heavy fuel oil, the heavy fuel oil being defined according to ASTM D396-98. Said liquid fuel derived from biomass is selected from the group consisting of neutrali sation oil and tall oil. Tall oil is said to be present in the fuel composition in a proportion varying from 1% by weight to 80% by weight, preferably from 5% by weight to 50% by weight, more preferably from 10% by weight to 30% by weight, with respect to the total weight of the fuel composition and the best results are said to be observed for the latter range (i.e. 10%-30% by weight). The use of the aforesaid liquid fuel derived from biomass is said to be able to stabilise the fuel composition, i.e. to keep the viscosity during storage practically constant.

[0011] International Patent Application WO 2019 / 122707 relates to a liquid fuel composition comprising a mixture comprising from 10% to 50% by mass of tall oil pitch, at least one compound derived from a terpene and at least one rosin ester, said compounds being derived from the treatment of resinous wood. The aforesaid fuel composition derived directly from biomass is said to be capable of being burnt in an industrial boiler or furnace instead of fossil fuel oil.

[0012] International Patent Application WO 2022 / 129681 relates to a method for producing marine fuel components comprising: a) supplying a raw material comprising tall oil pitch, b) submitting the raw material to hydrotreatment to produce a hydrotreated tall oil pitch, wherein said hydrotreatment is carried out at a pressure comprised between 30 barg and 200 barg, at a temperature comprised between 300°C and 350°C, in the presence of a hydrogen stream and of one or more hydrotreating catalysts, and c) fractionation of the hydrotreated tall oil pitch into a first fraction and a second fraction, wherein the second fraction is the marine fuel component. The aforesaid second fraction is said to be usable as a marine fuel as such or, alternatively, in a mixture with other renewable or fossil marine fuel components.

[0013] The aforesaid documents do not specifically mention fuel mixtures comprising marine fuel, in particular residual marine fuel [(“Residual Marine Fuel Oil” (RMFO) or “Heavy Marine Fuel Oil” (HMFO)] and tall oil as such, nor do they mention the ability of tall oil to redu ce the Conrandson carbon residue (CCR) of such fuel mixtures without adversely affecting the remaining characteristics.

[0014] The Applicant has set itself the problem of finding a fuel mixture comprising a specific marine fuel, in particular a residual marine fuel ["Residual Marine Fuel Oil" (RMFO) or "Heavy Marine Fuel Oil" (HMFO)] and tall oil, which can be obtained by a simple, energy-saving process, and which shows an improved Conrandson carbon residue (OCR) without negatively affecting the remaining characteristics such as, for example, sulphur content.

[0015] The Applicant has now found a fuel mixture comprising marine fuel, in particular residual marine fuel ["Residual Marine Fuel Oil" (RMFO) or "Heavy Marine Fuel Oil" (HMFO)], and tall oil, in specific quantities, said marine fuel having specific characteristics. Said fuel mixture can be obtained through a simple, energy-saving process, and shows an improved Conrandson carbon residue (CCR) compared to the starting marine fuel, without adversely affecting other characteristics such as, for example, sulphur content. Said fuel mixture can advantageously be used, as such, or in mixtures with other renewable or fossil marine fuels, in combustion engines for ships.

[0016] An object of the present invention is thus a fuel mixture comprising:

[0017] (a) from 80% by weight to 99.99% by weight, preferably from 85% by weight to 99.95% by weight, of marine fuel,

[0018] (b) from 0.01% by weight to 20% by weight, preferably from 0.05% by weight to 15% by weight, of tall oil; the sum of (a) + (b) being equal to 100; wherein said marine fuel has the following characteristics: a density, at 15°C, comprised between 890 kg / m3and 1010 kg / m3, preferably comprised between 910 kg / m3and 991 kg / m3; a kinematic viscosity, at 50°C, comprised between 6 mm2 / s and 700 mtn2 / s, preferably comprised between 20 mm2 / s and 500 mm2 / s; a total quantity of post-hot filtration sediments (TSA - “Total Sediment Aged”) less than or equal to 0. 1% m / m; an acidity (TAN - “Total Acid Number”) less than or equal to 2.5 mg KOH / g, preferably comprised between 0.05 mg KOH / g and 2.4 mg KOH / g; a Conradson carbon residue (CCR) less than or equal to 20% m / m.

[0019] For the purpose of the present description and of the following claims, the characteristics of marine fuel were measured according to ISO 8217:2017.

[0020] For the purpose of the present description and of the following claims, the definitions of the numerical intervals always comprise the extreme values unless otherwise specified.

[0021] For the purpose of the present description and of the following claims, the term "comprising" also includes the terms "which essentially consists of or "which consists of .

[0022] According to a preferred embodiment of the present invention, said marine fuel is a residual marine fuel [“Residual Marine Fuel Oil” (RMFO) or “Heavy Marine Fuel Oil” (HMFO).

[0023] According to a preferred embodiment of the present invention, said tall oil is crude tall oil (CTO) or tall oil pitch (TOP), preferably tall oil pitch (TOP).

[0024] As defined herein, crude tall oil (CTO - CAS registry number 8002-26-4) is preferably obtai ned as a by-product of kraft pulp or sulphite production processes, and tall oil pitch (TOP - CAS number 8016-81 -7) is the lower residual fraction of crude tall oil (CTO) distillation processes).

[0025] Crude tailoil (CTO) has a diverse chemical composition comprising resin acids, fatty acids and unsaponifiable compounds. Resin acids are a mixture of organic acids derived from terpene oxidation and polymerisation reactions. The main resinic acid present in crude tailoil (CTO) is abietic acid, but abietic derivatives and other acids, such as pimaric acid, are also found. Fatty acids are long-chain monocarboxylic acids and are present in hard and soft woods. The main fatty acids present in crude tailoil (CTO) are oleic, linoleic and palmitic acids. Unsaponifiable compounds cannot be made into soaps because they are neutral compounds that do not react with sodium hydroxide to form salts and include sterols, higher alcohols and hydrocarbons. Sterols are steroid derivatives that also include a hydroxyl group.

[0026] Tall oil pitch (TOP) typically comprises from 34% by weight to 51% by weight of free acids, from 23% by weight to 37% by weight of esterified acids, and from 25% by weight to 34% by weight of unsaponifiable compounds, relative to the total weight of tall oil pitch (TOP). Free acids are typically selected from a group consisting of dehydroabietic acid, abietic acid and other resin acids. Esterified acids are typically selected from a group consisting of oleic and linoleic acids. Unsaponifiable compounds are typically selected from the group consisting of diterpene sterols, high molecular weight fatty alcohols, sterols and dehydrated sterols.

[0027] According to a further preferred embodiment of the present invention, said tall oil may be used in a mixture with at least one polar solvent selected, for example, from: mono- or poly-alcohols such as, for example, methanol, ethanol, glycerin; ketones such as, for example, acetone, methyl ketone; ethers such as, for example, methyl ethyl ether, methyl tert-butyl ether.

[0028] According to a further preferred embodiment of the present invention, in said tall oil / at least one polar solvent mixture, said tall oil may be present in a quantity comprised between 5% by weight and 70% by weight, preferably comprised between 10% by weight and 60% by weight, relative to the total weight of said tall oil / at least one polar solvent mixture.

[0029] According to a preferred embodiment of the present invention, when using said tall oil / at least one polar solvent mixture, said fuel mixture comprises:

[0030] (a) from 80% by weight to 99% by weight, preferably from 85% by weight to 98.5% by weight, of marine fuel;

[0031] (b) from 1% by weight to 20% by weight, preferably from 1.5% by weight to 15% by weight, of tall oil / at least one polar solvent mixture; the sum of (a) + (b) being equal to 100.

[0032] The fuel mixture object of the present invention can be obtained by directly mixing tall oil into marine fuel, at a temperature comprised between 25°C and 290°C, preferably comprised between 30°C and 280°C, for a time comprised between 10 minutes and 180 minutes, preferably comprised between 15 minutes and 160 minutes.

[0033] Alternatively, the fuel mixture object of the present invention can be obtained by mixing the tall oil / at least one polar solvent mixture in the marine fuel, at a temperature comprised between 25°C and 290°C, preferably comprised between 30°C and 280°C, for a time comprised between 10 minutes and 180 minutes, preferably comprised between 15 minutes and 160 minutes.

[0034] As mentioned above, said fuel mixture can advantageously be used, either as such, or in a mixture with other renewable or fossil marine fuels, in combustion engines for ships.

[0035] Accordingly, it is a further object of the present invention the use of said fuel mixture as such, or in a mixture with other renewable or fossil marine fuels, in combustion engines for ships.

[0036] As mentioned above, the fuel mixture object of the present invention has an improved Conrandson carbonaceous residue (CCR) compared to the starting marine fuel.

[0037] The improvement of the Conrandson carbonaceous residue (CCR) was evaluated according to the following equations: EXAMPLES 1 -2

[0038] Mixtures of marine fuel and tall oil pitch

[0039] Tall oil pitch (Altapyne Pitch® - Ingevity) and marine fuel were placed in a 1 -litre flask, (quantities are given in Table 1): the whole was kept, at 100°C, under stirring, for 120 minutes, obtaining a fuel mixture that was characterised according to ISO 8217:2017.

[0040] In Example 1, the marine fuel BTZ (FUEL OIL 380 - 0.5% S RMG 380 - Eni S.p.A) was used, while in Example 2, the marine fuel ATZ ('RESIDUAL MARINE FUEL RME 180 3.5% S - Eni S.p.A), having the characteristics shown in Table 1 (measured according to ISO 8217:2017) was used.

[0041] Tall oil pitch was also characterised according to ISO 8217:2017. EXAMPLES 3-5

[0042] Mixtures of marine fuel and tail oil pitch / polar solvent mixture

[0043] The following mixtures were prepared for this purpose.

[0044] 2.5 g of tall oil pitch (Altapyne Pitch®' - Ingevity) and 2.5 g of glycerine (Merck) were placed in a 1 -litre flask: the whole was kept, at 100 °C, under stirring, for 120 minutes, obtaining a tall oil pitch / glycerine mixture (Mix 1).

[0045] Mix 2 and Mix 3 were also prepared, as follows.

[0046] 2.5 g of tall oil pitch (Altapyne Pitch®- Ingevity) and 2.5 g of acetone (Merck) were placed in a 1-litre flask: the whole was kept, at 60°C, under stirring, for 120 minutes, obtaining a tall oil pitch / acetone mixture (Mix 2).

[0047] 2.5 g of tall oil pitch (Altapyne Pitch® - Ingevity) and 2.5 g of ethanol (Merck) were placed in a 1-litre flask: the whole was kept, at 70 °C, under stirring, for 120 minutes, obtaining a tall oil pitch / ethanol mixture (Mix 3).

[0048] Mix 1 (Example 3), or Mix 2 (Example 4), or Mix 3 (Example 5), and marine fuel ATZ (RESIDUAL MARINE FUEL RME 180 3.5% S - Eni S.p.A.), having the characteristics shown in Table 1 (measured according to ISO 8217:2017), were placed in a 1-litre flask: the whole was kept, under stirring for 120 minutes: at 100°C (Mix 1 - Example 3); at 60°C (Mix 2 - Example 4); and at 70°C (Mix 3 - Example 5); obtaining a fuel mixture that was characterised according to ISO 8217:2017.

[0049]

[0050]

Claims

CLAIMS1. Fuel mixture comprising:(a) from 80% by weight to 99.99% by weight, preferably from 85% by weight to 99.95% by weight, of marine fuel;(b) from 0.01% by weight to 20% by weight, preferably from 0.05% by weight to 15% by weight, of tall oil; the sum of (a) + (b) being equal to 100; wherein said marine fuel has the following characteristics: a density, at 15°C, comprised between 890 kg / nri and 1010 kg / m3, preferably- comprised between 910 kg / m3and 991 kg / m3; a kinematic viscosity, at 50°C, comprised between 6 mm2 / s and 700 mm2 / s, preferably comprised between 20 mm2 / s and 500 mm2 / s; a total quantity of post-hot filtration sediments (TSA - “Total Sediment Aged”) less than or equal to 0.1% m / m; an acidity (TAN - “Total Acid Number”) less than or equal to 2.5 mg KOH / g, preferably comprised between 0.05 mg KOH / g and 2.4 mg KOH / g; a Conradson carbon residue (CCR) less than or equal to 20% m / m.

2. Fuel mixture according to claim 1, wherein said marine fuel is a residual marine fuel [“Residual Marine Fuel Oil” (RMFO) or “Heavy Marine Fuel Oil” (HMFO)].

3. Fuel mixture according to claim 1 or 2, wherein said tall oil is crude talloil (CTO) or tall oil pitch (TOP), preferably tall oil pitch (TOP).

4. Fuel mixture according to any of the previous claims, wherein said tall oil is used in a mixture with at least one polar solvent selected from: mono- or poly- alcohols such as methanol, ethanol, glycerin; ketones such as acetone, methyl ketone, ethers, such as methyl ethyl ether, methyl tert-butyl ether.

5. Fuel mixture according to claim 4, wherein in said tall oil / at least one polar solvent mixture said tall oil is present in a quantity comprised between 5% by- weight and 70% by weight weight, preferably comprised between 10% by weight and 60% by weight, with respect to the total weight of said tall oil / at least one polar solvent mixture.

6. Fuel mixture according to any of the previous claims, wherein in the case of using said tall oil / at least one polar solvent mixture, said fuel mixture comprises: (a) from 80% by weight to 99% by weight, preferably from 85% by weight to98.5% by weight, of marine fuel, (b) from 1% by weight to 20% by weight, preferably from 1.5% by weight to15% by weight, of tall oil / at least one polar solvent mixture; the sum of (a) + (b) being equal to 100.

7. Use of the fuel mixture referred to in any of claims 1 to 6, as such, or mixed with other renewable or fossil marine fuels, in combustion engines for ships.

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