Methods for processing ultramafic rock and uses thereof

Abstract

Processing ultramafic rock and uses thereof are described herein to manufacture hydrocarbon and / or alcohol compounds derived from the reaction of organic acids, ultramafic rock, and hydrogen (H2). In one aspect, a method of manufacture of at least one hydrocarbon, at least one alcohol, or a mixture of alcohols and hydrocarbons by selecting and mixing together at least one organic acid, ultramafic rock, and an aqueous solution. The inventors have found that by mixing together these compounds, a reaction takes place resulting in the formation of hydrocarbon and / or alcohol compounds from ultramafic rock.

Description

[0001] METHODS FOR PROCESSING ULTRAMAFIC ROCK AND USES THEREOF

[0002] RELATED APPLICATIONS

[0003] This application claims priority from USA patent application no. 63 / 655,766 dated 4 June 2024 WIPO DAS code 7198 the contents of which are incorporated herein.

[0004] TECHNICAL FIELD

[0005] Described herein are methods for processing ultramafic rock and uses thereof. More specifically, methods are described for manufacture of hydrocarbons and / or alcohols derived from the reaction of organic acids, ultramafic rock, and hydrogen (H2).

[0006] BACKGROUND

[0007] Methods of producing hydrocarbon and alcohol compounds are known in industry and widely used owing the value of these types of compounds.

[0008] Generation of hydrogen (H2) from ultramafic rocks is known to occur and this reaction may be enhanced by the introduction of acids. The purpose of acid addition is to aid in the release and oxidation of iron (Fe2+) present in these rocks to generate hydrogen.

[0009] The focus of hydrogen production from ultramafic rocks in existing publications is related to either producing and collect hydrogen itself (as a source of energy / fuel) and / or, to assess potential interactions with carbon dioxide (CO2) that may produce methane (CH4).

[0010] In these reactions between acids and ultramafic rock, the hydrogen and methane may evolve into gas forms making collection in natural and / or industrial systems difficult or impractical.

[0011] Additionally, to the inventor's knowledge, the utility of hydrogen produced through the hydrolysis of ultramafic rocks (i.e., serpentinization) and its subsequent interactions with introduced organic acids have not been disclosed. The inventors have found that organic acids and related carbon products may be used to aid in hydrogen production as well as to react with hydrogen to form hydrocarbons, alcohols, and / or a mixture of both.

[0012] Catalysation may be needed for hydrogen to react with organic acids to form alcohols (i.e., hydrogenation) and / or hydrocarbons. This has been demonstrated in published art with engineered catalysts and with introduced hydrogen such as from electrolysis. The cost of additional catalysing material addition may however detract from the use of this reaction process in industrial settings. It is simpler to extract hydrocarbons that already exists in ground deposits or use other processes to form alcohols than to react hydrogen and organic acids including addition of catalysing materials.

[0013] It may be useful to provide an alternative method of manufacturing hydrocarbon and / or alcohol compounds, particularly by using a rock source that provides an abundant hydrogen source and which may inherently also comprise catalysing materials thereby addressing drawbacks of existing reaction methods, or at least to provide the public with a choice.

[0014] Further aspects and advantages of the methods for processing ultramafic rock and uses thereof will become apparent from the ensuing description that is given by way of example only.

[0015] SUMMARY

[0016] As noted above, processing ultramafic rock and uses thereof are described herein to manufacture hydrocarbon and / or alcohol compounds derived from the reaction of organic acids, ultramafic rock, and hydrogen (H2).

[0017] In a first aspect, there is provided a method of manufacture of at least one hydrocarbon compound, at least one alcohol compound, or a mixture of hydrocarbon compounds and alcohol compounds, by selecting and mixing together to form a mixture: at least one organic acid; ultramafic rock; and an aqueous solution.

[0018] In a second aspect, there is provided at least one hydrocarbon compound, at least one alcohol compound, or a mixture of hydrocarbon compounds and alcohol compounds produced by selecting and mixing together to form a mixture: at least one organic acid; ultramafic rock; and an aqueous solution.

[0019] In a third aspect, there is provided a reacted ultramafic rock produced by selecting and mixing together to form a mixture: at least one organic acid; ultramafic rock; and an aqueous solution; allowing the mixture to react and obtaining reacted ultramafic rock after the reaction is completed post mixing.

[0020] The inventors found that the reaction rate has a self-governing rate whereby the organic acid used accelerates endogenous hydrogen production from the ultramafic rock which in turn accelerates the production of hydrocarbon compounds and / or alcohol compounds. Addition of external hydrogen may further drive the reaction rate and product output(s). Also the presence of catalysing materials in the ultramafic rock may further drive the reaction rate in a synergistic manner. Without catalysing materials, reaction pathways may not progress and products may not form or, at least not form at a commercially useful rate. With reactions aided by catalysing compounds inherent to ultramafic rock, the reactions minimise hydrogen loss where hydrogen is both difficult to collect and store.

[0021] The reaction dynamics and end products may be tailored.

[0022] The method may be beneficial in that hydrogen is transformed into hydrocarbon and / or alcohol compounds that can be more readily collected and stored without the complications of gaseous hydrogen processing and storage performed in the art.

[0023] The above and further advantages are described in detail below.

[0024] DETAILED DESCRIPTION

[0025] As noted above, processing ultramafic rock and uses thereof are described herein to manufacture hydrocarbon and / or alcohol compounds derived from the reaction of organic acids, ultramafic rock, and hydrogen (H2).

[0026] For the purposes of this specification, the term 'about' or 'approximately' or 'substantially' and grammatical variations thereof mean a quantity, level, degree, value, number, frequency, percentage, dimension, size, amount, weight or length that varies by as much as 30, 25, 20, 15, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1% to a reference quantity, level, degree, value, number, frequency, percentage, dimension, size, amount, weight or length.

[0027] The term 'comprise1and grammatical variations thereof shall have an inclusive meaning - i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components or elements. Method of Manufacture

[0028] In a first aspect, there is provided a method of manufacture of at least one hydrocarbon compound, at least one alcohol compound, or a mixture of hydrocarbon compounds and alcohol compounds, by selecting and contacting together to form a composition: at least one organic acid; ultramafic rock; and an aqueous solution.

[0029] In a second aspect, there is provided at least one hydrocarbon compound, at least one alcohol compound, or a mixture of hydrocarbon compounds and alcohol compounds produced by selecting and contacting together to form a composition: at least one organic acid; ultramafic rock; and an aqueous solution.

[0030] In a third aspect, there is provided a reacted ultramafic rock produced by selecting and contacting together to form a composition: at least one organic acid; ultramafic rock; and an aqueous solution; allowing the composition to react and obtaining reacted ultramafic rock after the reaction is completed post contact.

[0031] The inventors have found that by contacting together the above compounds, reactions take place resulting in the formation of hydrocarbon compounds and / or alcohol compounds from ultramafic rock.

[0032] Two Stages

[0033] The reaction process may be in two stages. The reaction process may be summarised as follows: STEP 1:

[0034] Mg / Fe Silicate (e.g., (Mg'Fe SiCU) + Organic Acid Oxidized Fe (solution / solid) + H2 + Carbon Source (e.g., Reacted Organic Acid) + Reacted Mg / Fe Silicate + Secondary Mineral Formation.

[0035] In this step, CO2 gas may evolve.

[0036] STEP 2:

[0037] [A] H2 + Carbon Source (e.g., Reacted Organic Acid) + Catalyst (optional, present already in the silicate and / or Added) Hydrocarbon + H2O (Similar to Fischer-Tropsch- Type [FTT] Reaction).

[0038] AND / OR

[0039] [B] H2 + Carbon Source (e.g., Reacted Organic Acid) + Catalyst (optional, present already in the silicate and / or Added) Alcohol + H2O

[0040] The optional catalyst noted above in step 2 may comprise metal oxides / (oxy)hydroxides and alloys. These catalysts may be inherent to the ultramafic rock or may be added. The catalyst is described further below.

[0041] All of the above reactions may occur using water as the aqueous solution or in gaseous forms e.g. steam.

[0042] The reaction may be characterised by a number of features described further below. The reaction products may be of value in a wide variety of industries and applications.

[0043] Hydrocarbon Compounds

[0044] The term 'hydrocarbon' and grammatical variations thereof as used herein refers to organic compounds consisting entirely of hydrogen and carbon atoms.

[0045] The at least one hydrocarbon compound may comprise: at least one alkane, at least one alkene, and combinations thereof.

[0046] The term 'alkane' and grammatical variations thereof as used herein refers to acyclic saturated hydrocarbons The at least one alkane may comprise: methane (CH4), ethane (CjHg), propane (CaHg), butane (C4H10) and combinations thereof. It is envisaged that the alkane may be any alkane with 1 to 20+ carbon atoms.

[0047] The term 'alkene' and grammatical variations thereof as used herein refers to a hydrocarbon containing a carbon-carbon double bond.

[0048] The at least one alkene may comprise: ethene (C2H4), propene (CaHg), and combinations thereof.

[0049] The type and size of hydrocarbon compound manufactured is understood to be a function of the organic acid used and the molecular weight and carbon chain size of the organic acid. Alkane and / or alkenes with different chemistry may be produced to those described above e.g. where the organic acid has seven or more carbon atoms along with the preponderance of saturated or unsaturated carbon bonds in the organic acid.

[0050] The hydrocarbon compound produced may further be used as a reaction source for alcohol production.

[0051] Alcohol

[0052] The term 'alcohol' and grammatical variations thereof as used herein refers to organic compounds comprising at least one hydroxyl functional group bound to a saturated carbon atom.

[0053] The at least one alcohol compound may be at least one primary alcohol, or at least one secondary alcohol, or at least one tertiary alcohol, or a combination of primary, secondary, and / or tertiary alcohols.

[0054] The at least one alcohol compound may comprise at least one monohydric alcohol, or at least one polyhydric alcohol, or a combination of monohydric alcohols and polyhydric alcohols.

[0055] The at least one alcohol compound may comprise: ethanol (CjHgO), methanol (CH3OH), isopropyl (CaHgO), and combinations thereof.

[0056] Like for the hydrocarbon above, the type and size of the at least one alcohol compound manufactured is understood to largely be a function of the organic acid used and the molecular weight and carbon chain size of the organic acid.

[0057] The alcohol compound produced may further be used as a reaction source for hydrocarbon production. Organic Acid

[0058] Organic acids are organic compounds with acidic properties, classified based on the number of carboxylic functions. In general, organic acids are weak acids. However, organic acids with phenol, enol, alcohol, and thiol groups are weaker than carboxylic acids. Organic acids vary in the number of hydroxy or carboxyl functional groups and carbon-carbon double bonds in their structures. Organic acids are categorised based on four characterisations: (1) the nature of carbon chain (aromatic, aliphatic, alicyclic, and heterocyclic); (2) saturation or unsaturation properties; (3) substituted or non-substituted features; and (4) the number of functional groups (mono, di- or tri-carboxylic).While a wide variety of organic acids are envisaged as being used in this method, in one example, the at least one organic acid may comprise at least one carboxylic acid group. The at least one organic acid may comprise six or fewer carbon atoms. The carbon atoms of the organic acid may be saturated or unsaturated.

[0059] The at least one organic acid may comprise organic acids selected from low molecular weight organic acids. For the purposes of this specification, the term 'low' in the context of the organic acids may refer to a molecular weight of less than approximately 215g / mol. In one example, the at least one organic acid may have a molecular weight of approximately 40 to 215g / mol.

[0060] In one example, the at least one organic acid may be selected from: oxalic acid (H2C2O4); citric acid (CgHgO?); malic acid (C4H6O5); acetic acid (CH3COOH); formic acid (HCO2H); tartaric acid (C4H6O6), and combinations thereof.

[0061] The at least one organic acid may be added to the mixture described as a liquid or in liquid form. The organic acid may be liquid at ambient temperature and pressure.

[0062] The mixture may comprise 0.1 to 50, or 1 to 45, or 1 to 40, or 1 to 35, or 1 to 30, or 5 to 30, or 10 to 30, or 15 to 25% by weight organic acid.

[0063] The mixture may comprise a 1:1 ratio by weight of at least one organic acid to ultramafic rock.

[0064] The ratio of at least one organic acid to ultramafic rock in the mixture may be from 1 part at least one organic acid to 0.1-100, or 1-100, or 1-90, or 1-80, or 1-70, or 1-60, or 1-50 parts ultramafic rock by weight. In one example, the ratio may be 1 part at least one organic acid to 100 to 1000 parts ultramafic rock. This ratio may occur in a geologic scenario where the organic acid only enters small veins in the ultramafic rock. The reaction rate and production of the hydrocarbon and / or alcohol compounds may tend to increase with a greater amount of organic acids present during the reaction. It is expected that a maximum amount of organic acids exists at which point no extra reaction products are produced, this being a function of available hydrogen and catalysing agents among other factors.

[0065] Organic acids were also found by the inventors to be of particular benefit to accelerate and / or enhance the rate of hydrogen H2 production. This added rate of acceleration / enhancement was not expected and makes the method of greater value through faster reaction rate. The addition of organic acids was found to increase the rate of hydrogen production by at least 5%, or 10%, or 15%o, or 20% by volume.

[0066] Ultramafic Rock

[0067] The term 'ultramafic rock' and grammatical variations thereof as used herein refers to a rock containing in total less than 60, or 55, or 50, or 45 wt. % silica (SiCh) with elevated magnesium and iron concentrations. The formation of ultramafic rocks is related to magmatic and mantle processes. Ultramafic rocks usually contain substantial olivine (generically noted as (Mg,Fe)2SiO4). Ultramafic rocks that undergo serpentinization (i.e., hydrolysis or reaction with water) are referred to as serpentinites where the extent of serpentinization and / or the abundance of the remaining primary minerals, such as olivine, are not directly defined.

[0068] The ultramafic rock may be selected from: olivine, pyroxene, amphibole, phyllosilicate, and combinations thereof.

[0069] The ultramafic rock may be milled crushed or otherwise processed to reduce the particle size of the rock. Reducing particle size may increase the surface area of the rock on which the reactions may take place and hence speed the reaction up. Reducing the particle size may also be useful to expose reactive crystal sites in the rock and therefore also aid the reaction kinetics and expose catalysing agents described further below.

[0070] The ultramafic rock may be in a form of: sand, sediment, rock, and combinations thereof.

[0071] The ultramafic rock may comprise magnesium silicates.

[0072] Catalyst

[0073] The ultramafic rock may comprise catalysing materials. The inventors have identified that ultramafic rocks have catalysing compounds present naturally. These naturally present compounds interact with hydrogen to enhance and / or guide hydrocarbon and / or alcohol formation in a way that was unexpected and not disclosed in the art.

[0074] The ultramafic rock may comprise catalysing materials at a concentration sufficient to catalyse a reaction between the at least one organic acid and hydrogen gas produced during the reaction of the at least one organic acid and the ultramafic rock to in turn produce the at least one hydrocarbon compound and / or the at least one alcohol compound.

[0075] Alternatively, catalysing materials may be added to supplement that inherent to the ultramafic rock. Alternatively, catalysing materials may be added where the ultramafic rock does not comprise sufficient catalysing materials to catalyse a reaction between the at least one organic acid and hydrogen gas produced during the reaction of the at least one organic acid and the ultramafic rock to in turn produce the at least one hydrocarbon compound and / or the at least one alcohol compound

[0076] The catalysing materials may be selected from at least one of: metal oxides, metal (oxy)hydroxides, metal alloys, and combinations thereof. The metal oxides, metal (oxy)hydroxides, metal alloys, and combinations thereof may be present in the ultramafic rock at a concentration sufficient to catalyse the reaction between the organic acid compound(s) and hydrogen gas to produce the hydrocarbon and / or alcohol compounds.

[0077] The term 'metal oxide' and grammatical variations thereof as used herein refers to crystalline solids that contain a metal cation and an oxide anion.

[0078] The term 'metal (oxy)hydroxide' and grammatical variations thereof as used herein refers to crystalline and / or amorphous solids that contain a metal cation and an oxide and / or a hydroxide anion.

[0079] The term 'metal alloy' and grammatical variations thereof as used herein refers to metals made by combining two or more metallic elements.

[0080] Catalysing concentrations of metal oxides, metal (oxy)hydroxides, metal alloys, and combinations thereof may optionally be added to the reaction compounds.

[0081] The metal oxides, metal (oxy)hydroxides, metal alloys may comprise at least one of: nickel, chromium, cobalt, iron, vanadium, rare earth elements (REE's), platinum group elements (PGEs) and combinations thereof. The metal oxide may comprise a spinel group mineral and iron oxides such as hematite. The spinel group may comprise the minerals chromite [FeCrjC and magnetite [FeaCU]), for example.

[0082] The metal (oxy)hydroxide may comprise any variety of diaspore group minerals such as goethite [FeOOH]).

[0083] The metal alloys may include a wide variety of Fe alloys with the most common being awurite (Ni2.3Fe)).

[0084] Aqueous Solution

[0085] The aqueous solution may be water. The aqueous solution may be mixed with the organic acid. For example, most organic acids are not pure (100%) acid and are typically mixed with a cosolvent such as water. In this example, water is the aqueous solution and the organic acid and aqueous solution (water) are presented together to the ultramafic rock and mixture.

[0086] The aqueous solution may be present at an amount sufficient rate to provide a liquid phase for mixing of the mixture.

[0087] The aqueous solution may be present at an amount of 1-99%, or 5-99%, or 5-60%, or 5-35%, or approximately 20% by weight water.

[0088] The aqueous solution may be present at a rate sufficient to form a slurry. The term 'slurry' in the context of this specification refers to a mixture of denser solids (the ultramafic rock typically) suspended in the aqueous solution. A slurry may be useful as a means to transport, convey or react the solids via the reaction described. A slurry form may also not dilute the solids too much that the reaction rate is impaired. As noted elsewhere, solids in the slurry may be in a granular or particle form. The granules or particles may settle below a certain transport velocity. The slurry may behave like a Newtonian or non-Newtonian fluid depending on the slurry contents however, in the inventor's experience, for the reaction described, the slurry may have generally Newtonian fluid properties.

[0089] A solid content of the slurry may be: 1-50%, or 1-40%, or 1-30%, or 1-20%, or 5-15%, or approximately 10% by weight. Hydrogen

[0090] Endogenous hydrogen may be generated during the method of manufacture. Endogenous hydrogen generation is a reaction between the aqueous solution, ultramafic rock, and / or organic acid that occurs when the mixture is put together.

[0091] External hydrogen may be added to the mixture. External hydrogen may replace endogenous hydrogen production or may be added in addition to the endogenous hydrogen produced during the reaction.

[0092] The hydrogen (endogenous or external if used) may preferentially react via the reaction chemistry described, to form the hydrocarbon and / or the alcohol compounds. The reaction rate and production of the hydrocarbon and / or alcohol compounds tends to increase with a greater amount of hydrogen gas. It is expected that a maximum amount of hydrogen exists at which point no extra reaction products are produced, this being a function of available organic acids and catalysing agents among other factors.

[0093] Reaction Dynamics

[0094] The reaction dynamics may be varied by adjusting at least one characteristic selected from: organic acid concentration; type of organic acid; ultramafic rock concentration and chemistry; the surface area of the ultramafic rock; rate of addition / production, if any, of hydrogen gas; residence time of the reaction materials; the temperature at which the reaction occurs; the pressure at which the reaction occurs; the presence and concentration of catalysing materials.

[0095] As indicated elsewhere in this description, the reaction rate and dynamics may be influenced by a number of factors. Reaction rate influencing factors may comprise those listed above although other factors may also influence the reaction rate e.g. reaction vessel characteristics or subsurface characteristics. Above Ground Reaction

[0096] The reaction may occur above ground. In this context, 'above ground' may refer to industrial processes completed using ultramafic rock extracted from a source.

[0097] The reaction compounds may be added to a sealed chamber. The sealed chamber may take a variety of sizes and forms e.g. a tube reactor.

[0098] The sealed chamber may be a contactor configured to receive and mix together different material phases therein. The sealed chamber may comprise at least one solid phase and at least one liquid phase during the reaction. The sealed chamber may comprise at least one solid phase, at least one liquid phase, and at least one gas phase during the reaction.

[0099] Gases added to the sealed chamber may be fed to the sealed chamber. This may be by injection of gas into the reactor e.g. into the liquid phase and / or the headspace (gas) phase. Injection may be at a point or multiple points e.g. a sparge ring.

[0100] Liquids added to the sealed chamber may be fed to or about a solid phase (generally comprising ultramafic rock) already located in the sealed chamber.

[0101] Temperature inputs may be added to or about the solid phase or ultramafic rock located in the sealed chamber.

[0102] The method of manufacture may occur at a temperature greater than or equal to: 25, or 50, or 75 or 100, or 125, or 150°C. In one example, the maximum envisaged temperature used may be approximately 250°C based on thermodynamic modelling completed by the inventors.

[0103] The method of manufacture may occur at a pressure greater than or equal to: 1, or 2, or 3, or 4, or 5 bar. The reaction may occur at a pressure up to approximately 700bar.

[0104] The mixture comprising the at least one organic acid, ultramafic rock and aqueous solution may be agitated, rotated or otherwise moved to encourage mixing during the reaction process.

[0105] Hydrocarbon compounds produced from the reaction may be separated from the sealed chamber as: a gas output, a liquid output, both a gas and a liquid output.

[0106] Alcohol compounds produced from the reaction may be separated from the sealed chamber as: a gas output, a liquid output, both a gas and a liquid output. Batch, Continuous or Semi-Continuous Processing

[0107] Subsequent to, or during, the reaction process, hydrocarbon compounds or alcohol compounds produced from the reaction may be separated.

[0108] The reaction may be a batch process where the reaction is left to progress as far as possible and the reaction products separated subsequent to the reaction process. In a batch process, the inputs (e.g. ultramafic rock, organic acid(s) and aqueous solution) may be added to a reaction chamber at the start of the reaction and not subsequently, altered in concentration.

[0109] Alternatively, the reaction may be a continuous or semi-continuous process where the reaction products may be separated during the reaction process on a continuous basis or on a periodic basis on changes in volume, measured weights, time intervals and so on. In this scenario, the reaction may also have inputs such as ultramafic rock, organic acids, catalysts, and aqueous solution added further to the reaction whilst the reaction takes place. Inputs may be added continuously or semi-continuously, for example in reaction to weight or volume change or on a time basis.

[0110] Subsurface Geologic Reaction

[0111] The ultramafic rock may, alternatively, be utilised in a subsurface geologic environment. In this example, the method of manufacture occurs in a subsurface geologic environment wherein, the at least one organic acid and the aqueous solution are combined with ultramafic rocks, the ultramafic rocks being located in a subsurface geologic environment.

[0112] Ultramafic rocks are found in the Earth's mantle and crust and deposits existing in a variety of locations geographically. The reaction method described herein may take place below ground in a sub-surface environment. This reaction may be controlled or at least influenced subsurface.

[0113] The reaction compounds may be combined in a subsurface geologic environment and the reaction products of hydrocarbon compounds and / or alcohol compounds extracted from the subsurface geological environment as or after the reaction occurs.

[0114] Subsequent to, or during, the sub-surface reaction process, produced hydrocarbon and / or alcohol compounds may be separated above ground e.g. via a piping network and separation downstream of the subsurface reaction. Product Separation

[0115] Products may be separated. Separation described above of produced hydrocarbon and / or alcohol compounds may be via washing, distillation, evaporation, filtration, PSA, absorption, dehydration, fractionation, phase separation, liquefaction or other standard hydrocarbon industry unit operations and methods.

[0116] Remaining reacted or unreacted ultramafic rock may be rinsed, dried, or simply separated and disposed of.

[0117] Reacted Ultramafic Rock

[0118] As noted above, the reacted ultramafic rock may be a by-product. The reacted ultramafic rock may have increased surface area and reactivity. The reacted ultramafic rock by-product may be used in other industrial, environmental, and / or climate change applications such as for example, enhanced rock weathering carbon dioxide (CO2) injection or enhanced CO2 mineralisation.

[0119] Advantages

[0120] The inventors have identified a reaction between ultramafic rock, aqueous solution and organic acids to produce high value compounds.

[0121] The reaction acts in an unexpected manner to produce hydrocarbons. The rate and concentration of H2 produced from ultramafic rock can be modified to the extent that H2 becomes both a product and a new reactant in the system. A wide variety of factors can increase H2, including reactions involving organic acids, by enhancing Fe oxidization opportunities. With H2 at sufficient / high levels, never expected to occur previously, it becomes reactive with a wide variety of carbon sources including organic acids.

[0122] The reaction is understood to be synergistic due to the combination of compounds used. Whilst not being bound by theory, the inventors found that the reaction rate has a self- governing rate whereby the organic acid used accelerates endogenous hydrogen production from the ultramafic rock which in turn accelerates the production of hydrocarbon compounds and / or alcohol compounds. Addition of external hydrogen further drives the reaction rate. Also the presence of catalysing materials in the ultramafic rock further drives the reaction rate in a synergistic manner.

[0123] The reaction dynamics and end products may be tailored. For example, the reaction speed may be altered through use of varied temperature and pressure. The chemistry of the hydrocarbon compounds or the alcohol compounds may be influenced by the type and concentration of organic acid used.

[0124] This method may be beneficial in that hydrogen is transformed into hydrocarbon and / or alcohol compounds that can be more readily collected and stored without the complications of gaseous hydrogen processing and storage performed in the art.

[0125] With reactions aided by catalysing compounds inherent to the ultramafic rock, the reactions occur faster and, this approach minimises hydrogen loss where hydrogen is both difficult to collect and store.

[0126] A further advantage identified is that hydrogen produced in an industrial above ground setting due to the reaction of ultramafic rocks can be directed towards forming a non-gaseous product which may be stored easily and used for other purposes.

[0127] A further advantage identified is that hydrogen produced in subsurface ultramafic rock systems will be retained in the subsurface system. This may negate the complexity of hydrogen extraction and storage.

[0128] The embodiments described above may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more said parts, elements or features.

[0129] Further, where specific integers are mentioned herein which have known equivalents in the art to which the embodiments relate, such known equivalents are deemed to be incorporated herein as if individually set forth.

[0130] BRIEF DESCRIPTION OF THE DRAWINGS

[0131] Further aspects of the methods for processing ultramafic rock and uses thereof will become apparent from the following description that is given by way of example only and with reference to the accompanying drawings in which: Figure 1 illustrates examples of different reaction pathways to formation of hydrocarbon / alcohol compounds and the reaction of organic acids, ultramafic rock, aqueous solutions, and hydrogen (H2);

[0132] Figure 2 illustrates a flow diagram of above ground (industrial) and below ground (sub-surface) applications of the described methods to process ultramafic rocks to generate hydrocarbon / alcohol compounds;

[0133] Figure 3 illustrates an example of an above ground apparatus used to complete the method described;

[0134] Figure 4 illustrates a graph showing the results of a trial to measure the reaction efficacy in terms of hydrocarbon and alcohol compound formation during ultramafic rock, hydrogen H2, and organic acid interactions;

[0135] Figure 5 demonstrates how temperature and pressure affect olivine rock hydrolysis as compared to the olivine rock composition;

[0136] Figure 6A-F illustrate graphs showing measurements of H2 concentration (ppm) produced during the trials by reacting solution A at different reaction conditions (temperature, concentrations of organic acid, type of organic acid, presence of catalyst, surface area);

[0137] Figure 7 illustrates a chromatogram showing the presence of ethanol as a fluid product of one of the tests conducted in accordance with the methods described;

[0138] Figure 8 illustrates a chromatogram peak area plot, for methane as a gas product of one of the tests conducted in accordance with the methods described; and

[0139] Figure 9 illustrates a simplified representation of a gas chromatogram overlay for a reaction mixture obtainable in accordance with the present invention, wherein the reaction gas mixture has been obtained at two different reaction times.

[0140] WORKING EXAMPLES

[0141] The above described methods for processing ultramafic rock and uses thereof are now described by reference to specific examples and the Figures and the following item numbering:

[0142] 100 Initial reaction box

[0143] 105 Hydrogen production 110 Catalysing reaction box

[0144] 120 Hydrocarbon and / or alcohols

[0145] 130 Separation step

[0146] 140 External hydrogen addition

[0147] 200 Ultramafic rock

[0148] 210 Rock processing

[0149] 220 Rock powder

[0150] 230 Reacting

[0151] 240 Produced hydrocarbons and alcohols

[0152] 250 Filtration / distillation

[0153] 260 Concentration / purification

[0154] 300 Subsurface geological environment

[0155] 310 Ultramafic rock deposit in the ground

[0156] 320 Production of hydrogen

[0157] 330 Formed hydrocarbons / alcohols

[0158] 340 Extraction from the subsurface environment

[0159] 400 Reactor

[0160] 410 Solid phase

[0161] 420 Liquid phase

[0162] 430 Gaseous phase

[0163] 440 Mixing

[0164] 450 Gas input

[0165] 460 Liquid input

[0166] 470 Solid input 480 Gas output

[0167] 490 Liquid output

[0168] EXAMPLE 1

[0169] In this example the method of manufacture is described with reference to specific examples.

[0170] Figure 1 illustrates two methods of manufacture labelled A and B to produce the described products of hydrocarbon and / or alcohol compounds (termed hereafter as hydrocarbons or alcohols).

[0171] Method A in Figure 1 in the first box 100 shows the initial reaction between the organic acids, ultramafic rock and water as the aqueous solution to produce hydrogen 105 via an oxidation reaction. Also present in the ultramafic rock are catalysing compounds that may urge the reaction dynamics so that organic acids, hydrogen compounds / molecules present react together (box 110 in Figure 1) to form the described hydrocarbons and alcohols 120.

[0172] Optionally, the hydrocarbons and alcohols may be separated in a further step 130. Optionally also, catalysing compounds (not shown) may be added at this step in addition to the catalysing compounds inherent to the ultramafic rock (if any are present).

[0173] Method B in Figure 1 is similar to method A however additional external hydrogen 140 is added during the initial step of endogenous hydrogen production 105. The addition of extra hydrogen 140 may force the reaction dynamics towards additional production of the hydrocarbons and alcohols 120.

[0174] EXAMPLE 2

[0175] In this example, an above ground industrial method of manufacture is described (method A in Figure 2) and a sub-surface geological method is described (method B in Figure 2).

[0176] Method A in Figure 2 shows ultramafic rock 200 processed 210 to a rock powder 220. This rock powder 220 is then reacted 230 by mixing the rock powder, water and organic acid(s) together in a sealed chamber. Hydrocarbons and / or alcohols 240 are produced. These may be filtered / distil led 250 and concentrated or purified 260. Also shown in Method A is the addition of hydrogen from an external source 270 to the reaction 230.

[0177] Method B in Figure 2 illustrates a schematic of a subsurface geological environment 300. In this example, organic acids and aqueous solution may be added to an ultramafic rock deposit in the ground 310. This causes the production of hydrogen 320 beneath the ground and subsequent hydrocarbon / alcohol formulation 330. The hydrocarbons / alcohols formed 330 may then be extracted from the subsurface environment 340.

[0178] EXAMPLE 3

[0179] In this example, a schematic reactor 400 is described with reference to Figure 3 to explain further one way the reaction may occur.

[0180] The reactor 400 as shown in Figure 3 may be a sealed chamber. The sealed chamber may be a contactor configured to receive and mix together different material phases solid 410, liquid 420, and gaseous 430 therein, mixing shown by arrow 440.

[0181] The reactor 400 may comprise at least one solid phase and at least one liquid phase during the reaction.

[0182] Gases produced during the reaction rise to the headspace 430 of the reactor 400. Gases inputs such as hydrogen gas may be added via input 450 into the headspace 430 area of the reactor 400.

[0183] Liquid inputs 460 such as the organic acids and aqueous solution may be added to the reactor 400 to a liquid phase area 420 of the reactor 400 or into or about a solid phase area 410 of the reactor 400.

[0184] Solid phase inputs (e.g. ultramafic rock) may be added or settles to the reactor 400 base 410.

[0185] Temperature inputs 470 may be added to or about the solid phase 410 or ultramafic rock located in the reactor 400. The reactor 400 may be heated to a temperature over 25°C during processing. The internal pressure may be 1 bar or greater during processing.

[0186] The mixture comprising the at least one organic acid, ultramafic rock and aqueous solution may be agitated, rotated or otherwise moved shown by arrows 440 to encourage mixing during the reaction process.

[0187] Hydrocarbons or alcohols produced from the reaction may be separated from the sealed chamber as: a gas output 480, a liquid output 490, both a gas 480 and a liquid output 490.

[0188] EXPERIMENTAL PART

[0189] MATERIALS

[0190] Mass spectrometer Mass spectrometry was used to identify organic compounds by ionizing them and measuring their mass-to-charge ratios, thereby, revealing molecular weight and structural details. This method was used to confirm the presence and abundance of hydrocarbons and alcohols from autoclave samples.

[0191] Hydrogen Meter

[0192] A handheld hydrogen detector (USA NIST Calibration) with an electrochemical cell sensor and a measurement range of 0-1000 ppm H2 was used for H2 measurements in gases present in the headspace of the autoclave. This instrument and H2 measurements were used to confirm / corroborate results obtained by gas chromatography.

[0193] Toluene Meter

[0194] A handheld toluene detector (USA NIST Calibration) with an electrochemical cell sensor and a measurement range of 0-100 ppm CgHsCHa was used for toluene measurements in gases present in the headspace of the autoclave. This instrument and toluene measurements were used to confirm / corroborate that a heavy organic molecule was / could be synthesized in the system.

[0195] Gas Chromatographer

[0196] Gas chromatography (GC) separates compounds based on their volatility and interaction with the column, allowing identification by retention time. By measuring peak areas in the resulting chromatogram and using standards, it was used to quantify the type and abundance of gases such as H2, CO2, and N2 and organic species in both gas and liquid samples.

[0197] Multiple measurements of hydrocarbons and alcohols obtained by different methods (mass spectrometry, handheld meters, and gas chromatography) with similar results provide greater confidence in products produced from the experiments performed.

[0198] Autoclave

[0199] A Parr Instruments autoclave allows rock powders and solutions to be reacted under controlled temperatures and pressures, simulating subsurface conditions. The sealed reactor enables sampling ports or valves to extract gases and liquid aliquots during the experiment, allowing real-time monitoring of chemical changes and evolved species over time.

[0200] METHODS

[0201] Rocks powders and solutions were loaded into the autoclave in order to react under specific conditions. Samples (gas and liquid) from the autoclave were monitored and measured over time using the methods described above. Rock powders from ultramafic rocks from Washington, USA, and New Zealand were assessed demonstrating similar results. Data and analyses from only the Washington ultramafic rocks are shown.

[0202] EXAMPLE 4

[0203] A pilot trial was completed to confirm the reaction process.

[0204] Ultramafic rock in the form of a powder and 10% concentration acetic acid as the organic acid, the balance of the acetic acid solution being water (as the aqueous solution) were mixed in a 1:1 ratio by weight to form a slurry. The powder contained ~10 wt. % of magnetite and chromite (i.e., potential catalysts).

[0205] The slurry was added to an autoclave, the autoclave acting as a sealed reaction chamber.

[0206] The temperature of the autoclave contents was heated to 50°C. Temperature changes were made for gas and liquid sampling as well as to modulate hydrogen production during the time frame of the experiment.

[0207] After 4.5 hours, gases in the headspace of the reactor and compounds evolved from the liquid in the autoclave were sampled and tested.

[0208] The presence of hydrogen H2, methane CH4, and ethanol were measured at 4.5 hours in the liquid and headspace using mass spectrometry (Figure 4). When the ultramafic powder was reacted with water (no acetic acid) under the same conditions, H2 and no hydrocarbons and / or alcohols were detected (not shown).

[0209] Results for the experiments completed showed that:

[0210] With ultramafic rock powder and water, hydrogen production was rapid where the hydrogen was mainly present as a gas in the headspace; Hydrogen concentration drops when organic acids are added (which are converted to methane and ethanol in this experiment);

[0211] No hydrocarbons or alcohols were detected in solution or in the headspace at the start of the experiment as expected;

[0212] Ethanol was present in both the liquid phase and the gas head space;

[0213] Acetic acid concentrations decreased as expected due to the reaction that occurs. The pH was initially acidic and after reacting the pH values increased to >4.5 further illustrating the chemical change that occurs to the organic acids.

[0214] These experiments demonstrate that acetic acid (a low molecular weight organic acid) reacting with ultramafic rock utilised hydrogen (endogenous) to produce both a hydrocarbon (CH4) and alcohol (ethanol).

[0215] The combination of ultramafic rock and organic acid serves as a mediator to create and then transform hydrogen added to the system to hydrocarbons and / or alcohol.

[0216] Figure 5 demonstrates how ultramafic rock composed of olivine reacting with water (i.e., serpentinization) to produce hydrogen H2 may be further modified using pressure and temperature. These variations may be used to modify reactions to adjust endogenous hydrogen production.

[0217] In summary, Figure 5 shows that:

[0218] - High pressure (5kbar) and temperatures between 25-400°C are conducive to H2 formation related to the serpentinization of most Earth olivine (F090). Lower temperatures may be preferable; and

[0219] - At low pressure (1 bar) and liquid-vapor saturation pressures, Earth olivine (F090) will produce H2 over a wide temperature range. Experiments demonstrate that H2 production is optimal between 25 to 200°C.

[0220] EXAMPLE 5

[0221] Further tests were carried out to illustrate the benefits of the present invention.

[0222] For each test, the general procedure here below was followed:

[0223] 100 grams of the ultramafic rock (olivine) used in EXAMPLE 4 and 200 mL of solution A were added into an autoclave in which temperature was controlled and gases / fluids were monitored. Rotation rate of the autoclave stirrer was 120 rpm. Gas and fluid analyses were analysed immediately following extraction from the autoclave using GC, and / or by means of handheld gas meters (for hydrogen and toluene). All peaks for the sample in the gas chromatograph were identified using knowns / standards. As samples were collected over time, rates and temporal changes in gas and fluid chemistry were identified. During these tests, a variety of organic acids were reacted with ultramafic rock at different temperatures and concentrations, and the resulting products identified by means of GC. The tests conducted are summarised in Table 1.

[0224] Table 1

[0225] Figures 6A-F illustrate graphs showing measurements of H2 concentration (ppm) produced during the trials by reacting solution A at different reaction conditions (temperature, concentrations of organic acid, type of organic acid, presence of catalyst, surface area).

[0226] In particular, Figure 6A illustrates that acids increase / enhance the production of H2 relative to only having water in the system. Figure 6B illustrates that an increase in temperature (from 22°C to 50°C) enhances H2 production for the same organic acid. Figure 6C illustrates that 1 and 10 % Acetic acid provided similar results. Figure 6D illustrates that different organic acids (acetic acid, citric acid) provide for different enhancements to H2 production. Figure 6E illustrates that the use of a catalyst, in this case a chromite (FeC^CU) catalyst, increases H2 production. Figure 6F illustrates that increasing surface area of the ultramafic rock (from a block to powder form) increases H2 production. The rates of H2 illustrated in Figures 6A-6F are not necessarily reflective of the true rate of H2 production due to the possible partial consumption of H2 by organic compounds to form hydrocarbons and alcohols. At times greater than 5000 minutes in some of the tests, H2 has been seen to begin to decrease potentially due to the formation of species more reactive with it. All lines in Figures 6A-6F were created using a logarithmic regression fit of the collected points / samples. For all Figures 6A-6F, the y-axis denotes the Hydrogen Concentration (ppm) and the x-axis the Time (minutes).

[0227] Table 2 lists observed reaction product parameters for some tests, meaning H2 production, Hydrocarbons (HCs) levels, Alcohol(s) presence, Organic compounds presence (excluding organic acid or alcohols). For each test 1-6, volume of acid, mass of ultramafic rock and surface area were equivalent.

[0228] Table 2

[0229] Figure 7 illustrates a chromatogram obtained during the monitoring of the tests by means of GC. Figure 7 shows a very clean ethanol peak in the gas chromatograph for fluid collected from test 3 (1% acetic acid, 50 °C).

[0230] Figure 8 illustrates a plot of peak area for methane obtained for test No. 2 (10% acetic acid, 50 °C), wherein methane peak area which can be converted into CH4 concentration. The tests conducted demonstrate the benefits of the present invention of providing novel methods for obtaining H2, hydrocarbons and / or alcohols from ultramafic rocks, which H2, hydrocarbons and / or alcohols have been identified by means of both mass spectrometry and gas chromatography.

[0231] Figure 9 illustrates a simplified representation of a gas chromatogram overlay for a reaction mixture obtainable in accordance with the present invention. In particular, Figure 9 illustrates gas chromatograms for gas samples sampled from the reaction mixture for the reaction carried out in test No. 6, wherein olivine was reacted with 10% acetic acid at 50 °C in the presence of FeCr2O4 as catalyst. Figure 9 illustrates an overlay of 3 plots, a first plot at 0 hours, at the start of the reaction, a second plot 1 hour after the start of the reaction, and a third plot at 28 hours after the start of the reaction.

[0232] At 0 hours, air was used to standardize the GC and to confirm the absence of organic compounds (demonstrated by the absence of peaks / wiggles). At 1 hour, a gas sample was collected from the autoclave, where test No. 6 was carried out, and analyzed by GC. The gas chromatogram obtained for the collected sample is shown in Figure 9, which illustrates many peaks indicating the presence of variety of organic compounds. The presence of methanol and ethane could be determined by means of comparison with standards on hand. The present gas chromatogram further illustrates heavier and heavier species are obtained with an increase of reaction time. At 28 hours, after the start of the reaction, a further gas sample was collected from the autoclave, and analyzed by GC. Figure 9, illustrates that a varieties of organic compounds are obtained (different peaks denote different species), and that the amount of said species e.g. ethane and methanol also changes (different peak areas).

[0233] In conclusion, for each test No. 2 to 7, H2, methane, ethane, methanol, ethanol and toluene, alongside many other organic species, could be obtained.

[0234] Aspects of the methods for processing ultramafic rock and uses thereof have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope of the claims herein.

Claims

WHAT IS CLAIMED IS:

1. A method of manufacture of at least one hydrocarbon compound, at least one alcohol compound, or a mixture of hydrocarbon compounds and alcohol compounds, by selecting and mixing together to form a mixture: at least one organic acid; ultramafic rock; and an aqueous solution.

2. The method as claimed in claim 1 wherein the at least one hydrocarbon compound comprises: at least one alkane, at least one alkene, and combinations thereof.

3. The method as claimed in claim 2 wherein the at least one alkane comprises: methane (CH4), ethane (CzHg), propane (CaHg), butane (C4H10), and combinations thereof.

4. The method as claimed in claim 2 wherein the at least one alkene comprises: ethene (C2H4), propene (CaHg), and combinations thereof.

5. The method as claimed in claim 1 wherein the at least one alcohol compound comprises: ethanol (CzHgO), methanol (CH3OH), isopropyl (CaHgO), and combinations thereof.

6. The method as claimed in claim 1 wherein the at least one organic acid comprises at least one carboxylic acid group.

7. The method as claimed in claim 1 wherein the at least one organic acid comprises six or fewer carbon atoms.

8. The method as claimed in claim 1 wherein the at least one organic acid has a molecular weight of approximately 40-215g / mol.

9. The method as claimed in claim 1 wherein the at least one organic acid is selected from: oxalic acid (H2C2O4); citric acid (CgHgO?); malic acid (C4H6O5); acetic acid (CH3COOH); formic acid (HCO2H); tartaric acid (C HGOG) acids, and combinations thereof.

10. The method as claimed in claim 1 wherein the mixture comprises 0.1 to 50% by weight organic acid.

11. The method as claimed in claim 1 wherein the mixture comprises at least 1 part by weight of at least one organic acid to 0.1 to 100 parts by weight of ultramafic rock.

12. The method as claimed in claim 1 wherein the ultramafic rock is selected from: olivine, pyroxene, amphibole, phyllosilicate, and combinations thereof.

13. The method as claimed in claim 1 wherein the ultramafic rock is in a form of: sand, sediment, rock, and combinations thereof.

14. The method as claimed in claim 1 wherein the ultramafic rock comprises catalysing materials at a concentration sufficient to catalyse a reaction between the at least one organic acid and hydrogen gas produced during the reaction of the at least one organic acid and the ultramafic rock to in turn produce the at least one hydrocarbon compound and / or the at least one alcohol compound.

15. The method as claimed in claim 14 wherein the catalysing materials are selected from at least one of: metal oxides, metal (oxy)hydroxides, metal alloys, and combinations thereof.

16. The method as claimed in claim 1 wherein catalysing materials are added to a concentration sufficient to catalyse a reaction between the at least one organic acid and hydrogen gas produced during the reaction of the at least one organic acid and the ultramafic rock to in turn produce the at least one hydrocarbon compound and / or the at least one alcohol compound17. The method as claimed in claim 16 wherein the catalysing materials are selected from at least one of: metal oxides, metal (oxy)hydroxides, metal alloys, and combinations thereof.

18. The method as claimed in claim 1 wherein the aqueous solution is water, and the aqueous solution is present at a sufficient rate to provide a liquid phase for mixing of the mixture.

19. The method as claimed in claim 1 wherein the aqueous solution is present at a rate sufficient to form a slurry, a solid content of the slurry being 1-50% by weight.

20. The method as claimed in claim 1 wherein endogenous hydrogen is generated during the method of manufacture.

21. The method as claimed in claim 20 wherein endogenous hydrogen is generated during the method of manufacture at an accelerated relative to if no organic acids were used to complete the method.

22. The method as claimed in claim 1 wherein external hydrogen is added to the mixture.

23. The method as claimed in claim 1 wherein the method of manufacture occurs within a sealed chamber comprising a contactor configured to receive and mix together different material phases therein.

24. The method as claimed in claim 1 wherein the method of manufacture occurs at a temperature equal to or greater than 25°C.

25. The method as claimed in claim 1 wherein the method of manufacture occurs at a pressure equal to or greater than 1 bar atmospheric.

26. The method as claimed in claim 1 wherein the method of manufacture occurs in a subsurface geologic environment wherein, the at least one organic acid and the aqueous solution are combined with ultramafic rocks, the ultramafic rocks being located in a subsurface geologic environment.

27. At least one hydrocarbon compound, at least one alcohol compound, or a mixture of hydrocarbon compounds and alcohol compounds produced by the method of manufacture as claimed in claim 1.

28. Reacted ultramafic rock produced by completing the method of manufacture as claimed in claim 1; and obtaining reacted ultramafic rock after the reaction is completed post mixing.

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