CN111971402A

CN111971402A - Method for producing solid composite material

Info

Publication number: CN111971402A
Application number: CN201980025984.XA
Authority: CN
Inventors: 李春柱; 李婷婷
Original assignee: Renergi Pty Ltd
Current assignee: Renergi Pty Ltd
Priority date: 2018-04-16
Filing date: 2019-04-11
Publication date: 2020-11-20
Also published as: WO2019200424A1; AU2019254838A1; AU2019254838B2; JP2021521342A; JP7365360B2; CN116622984A

Abstract

The present disclosure provides methods of producing solid composite materials. The method includes providing a biomeal formed from a thermal treatment of a carbonaceous feed including biomass. The biomeal is capable of hardening at elevated temperatures. The method further includes mixing the biomeal with the solid or paste to form a raw composite material, and heating the raw composite material to produce a hardened solid composite material.

Description

Method for producing solid composite material

Technical Field

The present invention relates to a method of producing a solid composite material, in particular a composite material containing minerals.

Background

Many industrial processes are both energy intensive and carbon intensive. Examples of such processes include the production of iron and steel from iron ore minerals and the production of silicon from silica minerals. Fossil fuels, such as coal, are often the primary source of energy and carbon. For example, metallurgical coke from the coking of high quality pitch-bonded coal is the predominant form of carbon used in the steel industry, especially in the feed to blast furnaces. These industrial sectors are greenhouse gases (especially CO)₂) And actively search for alternative and low emission means to supply the energy and carbon required in the process.

Although many renewable energy sources are available to meet the energy requirements of such industrial processes to reduce their CO₂Emissions, but biomass is the only renewable energy source that can be directly used to meet the carbon requirements of these industrial processes.

Beneficiation is a process commonly used to improve the quality (purity) of raw minerals such as iron ore. It generally involves comminution and thus the production of fine mineral material. The fines must then be made into large particles, for example by granulation or briquetting, so that the fines become feed in the form of large particles, such as pellets and briquettes, which are suitable for the desired process, for example as feed for a blast furnace. Clays, such as bentonite, are commonly used as binders. However, such inorganic binders will tend to introduce undesirable inorganic impurities into the process, which may adversely affect the main process and ultimately be discharged from the process as slag that needs to be disposed of. Organic binders would be desirable, especially if they could also physically and/or chemically interact with the mineral matter to be processed to form a composite material and become part of the carbon required in the process. In composites that give high mechanical strength, a chemical reaction between the binder and the mineral will be advantageous.

Although carbon can also be an energy source, the "carbon" required by the above-mentioned industrial sectors is usually a reactant, for example as a reducing agent, to reduce iron ore to iron, or silica to silicon. As used herein, "carbon" does not have to be pure carbon, but refers primarily to carbon-rich carbonaceous materials. Metallurgical coke and activated carbon are typical examples of these "carbon" materials. The intimate contact between the carbonaceous material and the mineral to be reacted (reduced) in the composite material will have a number of beneficial effects on process acceleration and process efficiency.

Many fines may be produced during the production of the carbon material and/or during subsequent preparation of the carbon material so that the carbon material in the desired particle size range may be fed to a desired industrial process, such as a blast furnace or electric arc furnace. For example, many metallurgical coke fines may be produced when metallurgical coke is crushed so that coke of the desired particle size range can be produced and fed to the blast furnace. These coke fines may not be fed directly into the blast furnace and have a lower commercial value than the coke slab. Another example is the production of biochar fines during the production and preparation of biochar as a feedstock that can be fed to an electric arc furnace to produce silicon. Also, the biochar fines cannot be fed to the electric arc furnace and have a lower commercial value than the biochar blocks. The use of corresponding fines to produce bulk carbon material would be an important commercial achievement. In particular, the lumped carbon materials produced from the fines should meet the quality requirements of the intended use, for example the coke slab should have sufficient mechanical strength required for blast furnaces for producing iron and steel, or the biomass slab should have sufficient mechanical strength required for electric arc furnaces for producing silicon.

The scope of the invention should in no way be limited by the examples cited above. Other examples can be cited where the fines should be made into large particles, as large particles have a higher commercial value than fines.

Biocoarse material can be produced from the thermal treatment of biomass at elevated temperatures and used as a binder or as a component in a binder. A typical type of bio-crude is bio-oil from the pyrolysis of biomass (which also produces a solid by-product called biochar). Upon heating, the bio-oil may devolatilize and harden. Bio-oils contain a rich set of reactive structures and functional groups that can react with minerals to create very strong bonds between the minerals and components derived from the bio-crude. Hydrothermal liquefaction of biomass can also produce reactive biomeal. The biomeal may also serve as a binder for other materials, such as metallurgical coke fines and/or biochar fines.

Organic binders can decompose at high temperatures, releasing flammable volatiles. The use of carbon as a reductant may also produce gases such as CO with useful heating values. The recovery of the energy values of these volatiles and gases will be important to the overall process energy efficiency.

The carbon in the organic binder may also become part of the carbon required in the process of upgrading minerals, for example, as a reductant in a blast furnace or similar process to reduce iron ore to iron.

Therefore, there is a need to develop organic binders from biomass and/or to bring carbon in intimate contact with the ore (or other material to be combined) in the composite material into a high temperature process, for example for the reduction of iron ore to iron.

Disclosure of Invention

According to a first aspect of the present invention, there is provided a method of producing a solid composite material, the method comprising:

providing a biomeal formed from a heat treatment of a carbonaceous feed comprising biomass, the biomeal being capable of hardening at an elevated temperature;

mixing the biomeal with the solid or paste to form a crude composite; and

heating the raw composite material to produce a hardened solid composite material.

Embodiments of the present invention have significant advantages. In particular, the resulting solid composite material may have a relatively high density and strength. Furthermore, the resulting solid composite material may have a relatively low sulfur content and the biocrude may not introduce undesirable impurities into the composite material. Furthermore, the biomeal may contain a useful substance that may act as a flux, for example, in a subsequent steelmaking process.

As used herein, the term "biomass" refers to any material derived from a living or recently living organism. While biomass is the preferred feed for the production of organic binders due to its potential carbon neutrality and other characteristics of biomass, other carbonaceous feeds may be used as the feed, including various carbonaceous renewable and non-renewable feeds, including but not limited to coal, solid waste, or mixtures thereof. The solid waste may include, but is not limited to, agricultural waste, forestry waste, and domestic/municipal solid waste or residues from the processing of carbonaceous feedstocks. In fact, in a broad sense, many solid wastes are considered as biomass. Alternatively, biomass is at least a significant component of many solid wastes.

As used herein, the term "heat treatment" is intended to include within its scope any process at elevated temperatures, with or without the presence of additional substances. For example, pyrolysis of biomass in an inert, oxidizing or reducing atmosphere is a thermal treatment process. Hydrothermal treatment of biomass in subcritical, critical or supercritical water is another heat treatment process.

As used herein, the term "biocrude" is intended to include any liquid or paste product resulting from the thermal treatment of biomass or other carbonaceous feedstock. Bio-oil from the pyrolysis of biomass is a typical bio-crude.

As used herein, the term "biochar" (or "char") is intended to include solid products from the thermal treatment of biomass or other carbonaceous feedstocks.

As used herein, the term "composite material" is intended to include within its scope any material composed of two or more constituent materials having different properties. "crude composite" refers to a mixture of precursors that produce the final solid composite. The raw composite material may be in the shape of pellets and lumps or any other regular or irregular shape and be of any size.

The process of the present invention can be carried out at a wide range of relative proportions between the biomeal and the solids to produce solid composites having widely varying compositions and characteristics.

In an embodiment, the solids comprise minerals, such as iron ore or silica. For example, the solid may be magnetite iron ore.

In another embodiment, the solid comprises a solid carbon material. For example, the solid may be metallurgical coke, biochar, or charcoal.

In one embodiment, the solid may have a wide range of particle sizes. For example, magnetite iron ore fines, either separately beneficiated or together with magnetite rocks, may be mixed with bio-oil to make a crude composite. The solids may contain impurities including, but not limited to, water.

In a further embodiment, the solids may be in the form of a slurry, meaning water or other chemical.

In an embodiment, the solid comprises a mixed solid. For example, the solids may be a mixture of magnetite and hematite iron ore, along with other impurities. Alternatively, the solids may be a mixture of ore and biochar or a mixture of ore and metallurgical coke.

In a further embodiment, the raw composite material may include a fluxing agent, such as lime, to facilitate subsequent processing of the composite material.

In still further embodiments, the crude composite material may include additional chemicals, including catalysts, to accelerate the hardening of the composite material.

The step of heating the crude composite material may be carried out by heating the crude composite material to a temperature between 100 ℃ and 600 ℃, preferably between 150 ℃ and 450 ℃ and still more preferably between 200 ℃ and 350 ℃. The heating may be carried out in an inert atmosphere or a reducing atmosphere or an oxidizing atmosphere.

In another embodiment, the step of heating the crude composite material may be performed by heating the crude composite material to a temperature above 600 ℃ under an inert or reducing or oxidizing atmosphere.

In an embodiment, the step of heating the crude composite material is performed in a stepwise manner. For example, the temperature may be gradually increased at different heating rates and for various holding periods at selected temperature levels.

The process may comprise the further step of carbonizing the composite material at an elevated temperature, preferably above 600 ℃, more preferably above 800 ℃ and still more preferably above 1000 ℃, particularly but not exclusively the biocrude-derived carbon-containing component of the carbonized composite material.

The method may include the further step of combusting the composite material by reaction with an oxidant, such as air, to at least partially melt or recrystallize the solids in the composite material to achieve better mechanical strength.

According to a second aspect of the present invention, there is provided a method of producing a solid composite material, the method comprising:

providing biochar formed from heat treating a carbonaceous feed comprising biomass;

mixing the biomeal and biochar with a solid or paste to form a crude composite; and

The inclusion of biochar in the crude composite material can advantageously increase the carbon content of the composite material. Biochar and biomeal can be produced by thermal treatment of the same or different carbonaceous feedstocks.

According to a third aspect of the present invention there is provided a method of producing a solid composite material, the method comprising:

mixing the biomeal with the solid or paste to form a crude composite;

heating the raw composite material to produce a hardened solid composite material; and

volatiles released by heating the crude composite are recovered.

According to a fourth aspect of the present invention there is provided a method of producing a solid composite material, the method comprising:

mixing the biomeal and biochar with a solid or paste to form a crude composite;

volatiles released by heating the crude composite are recovered.

Biochar and biomeal can be produced by thermal treatment of the same or different carbonaceous feedstocks.

In an embodiment of the third or fourth aspect of the invention, the step of recovering the volatiles comprises feeding the volatiles to a combustion unit to provide heat energy to heat the crude composite.

In a further embodiment of the third or fourth aspect of the present invention, the step of recovering the volatiles comprises cooling the volatiles to form a liquid and non-condensable gas mixture. The liquid or non-condensable gas mixture may be used alone or together as a fuel to supply the thermal energy required to heat the raw composite or for other purposes.

In a specific embodiment of the third or fourth aspect of the invention, the recovered volatiles are used as fuel for power generation. Any suitable method of generating electricity, known now or in the future, such as using an internal combustion engine or gas turbine, may be used for this purpose.

Drawings

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings:

FIG. 1 is a flow diagram of a method of producing a solid composite material according to an embodiment of the invention;

Detailed Description

Embodiments of the present invention relate to methods of producing solid composite materials. To produce a solid composite material, a biomeal formed by thermal treatment of biomass or other carbonaceous feedstock or mixtures thereof is provided, wherein the biomeal is capable of hardening when heated. Without having to follow any particular theory, the hardening process involves complex chemical reactions involving reactive species and functional groups in the biomeal and solids forming part of the crude composite material, in addition to the evaporation of water and light materials from the biomeal. The description of the embodiments herein focuses on bio-oil from pyrolysis of biomass, but the bio-coarse in the present invention is not limited to bio-oil alone. Various biomass pyrolysis technologies now known or later invented may be used to produce bio-oil. For example, the mill pyrolysis technology (PCT/AU2011/000741) is very effective in producing bio-oils for use in producing composites using the methods of the present invention. The pyrolysis process also typically produces a solid by-product biochar and gaseous by-products including non-condensable gases. Biochar may also be used as a feed for producing solid composites in the present invention.

Bio-oils are mostly liquids, but one skilled in the art will recognize that bio-oils may contain colloids and even solids (including biochar). In addition to water, bio-oils can contain many organic compounds that contain various chemical functional groups, especially oxygen-containing functional groups. Bio-oils may also contain dissolved organics and inorganic solids such as sodium, potassium, magnesium and calcium salts. They may have beneficial effects for subsequent processes using the composite as a feed. For example, in the steel industry, they may act as fluxes in blast furnaces. In some pyrolysis processes, bio-oil is produced in the form of a paste or slurry. In some pyrolysis processes, a slurry of bio-oil and bio-char is produced directly.

The bio-oil is mixed with the solids to produce a crude composite. In an embodiment, the bio-oil is mixed with magnetite iron ore to produce a crude composite material comprising bio-oil and magnetite. In another embodiment, bio-oil and bio-char are mixed with magnetite ore to produce a crude composite material. In further embodiments, various additional chemicals are also added to the mixture to produce a crude composite material having different properties.

In a further embodiment, the bio-oil is mixed with a carbon material to produce a crude composite material. The carbon material may be metallurgical coke or biochar or any solid from the thermal treatment of carbonaceous feed. Additional chemicals, including catalysts, may also be components of the crude composite.

The mixing process can be performed in various ways and the crude composite can be produced in various shapes. The bio-oil and solids can be extruded into a crude composite material having a desired shape. In an embodiment, the pelletizing disks are used to mix and roll bio-oil, which may also include bio-char or any other component chemical as described above, with iron ore into a briquette. In a further embodiment, a granulation drum is used.

The relative proportions of bio-oil, iron ore and other components in the composite, including biochar and additional chemicals, can be varied over a wide range to suit the needs of the subsequent process in which the composite is used.

The crude composite is then heated to produce the final solid composite product. Heating may be performed in various ways in an inert atmosphere, a reducing atmosphere, or an oxidizing atmosphere to harden the composite material.

During heating, many physical processes and chemical reactions can occur. Moisture, such as that in bio-oil or iron ore, will evaporate. Some of the light components in the bio-oil will also evaporate. Depending on the temperature, the reactive functional groups in the bio-oil will also undergo various reactions, especially cracking and polymerization reactions, to produce additional lighter and heavier components. The heavy component is particularly important for binding together solid (e.g. ore) particles.

Without being bound to any particular theory, the components in the bio-oil may also react with solids (e.g., iron ore, biochar, or other carbon materials) to form some new chemical bonds between the bio-oil components and the iron ore. This type of chemical bond will be much stronger than the physical interaction/force, greatly contributing to the mechanical strength of the composite product.

Heating of the crude composite material can be performed in various ways. In an embodiment, the crude composite material is heated in an oxidizing atmosphere to combust at least some of the bio-oil components. The combustion will heat the raw composite material to high temperatures, causing some degree of melting/sintering of the iron ore, where recrystallization or other physico-chemical processes can take place to produce a composite material with high mechanical strength. Some of the iron ore may also be at least partially reduced while being combusted. The combustion process can be performed on the raw composite or on the final composite product.

In the steel industry, composite materials derived from bio-oil and iron ore and/or composite materials derived from bio-oil and metallurgical coke can be used as part of the feed to the blast furnace. A composite material derived from bio-oil and solid bio-char (or other type of char) may be fed to an electric arc furnace to produce silicon.

The volatiles released by heating the crude composite can contain many flammable components. If heated at relatively low temperatures (e.g., less than about 600℃.), some of these volatile components may condense to produce liquid fuel and non-condensable gaseous fuel.

Iron ore can be an excellent catalyst for reforming the released volatiles into light gases. Thus, in a specific embodiment, the composite material produced in the present invention is used for integration with an electrical power generation process, wherein volatiles and gases released by heating of the crude composite material are used for power generation using a power generation device. Examples of such power generation devices include, but are not limited to, internal combustion engines, gas turbines, and fuel cells.

Referring now to fig. 1, a flow chart illustrating a method 100 is shown, in accordance with an embodiment of the present invention.

In a first step 102, a biomeal formed by thermal treatment of biomass and capable of hardening is provided. In this embodiment, the biomeal is a bio-oil obtained from the pyrolysis of biomass.

In step 104, biochar is provided. Although bio-oil and bio-char are typically produced simultaneously from pyrolysis of the same biomass, bio-oil and bio-char may also be produced from different biomasses and using different thermal treatment processes.

Specific examples of pyrolysis processes are described in more detail in PCT international patent application No. PCT/AU 2011/000741.

In the next step 106, bio-oil and bio-char are mixed together with the solids to form a crude composite material. In this particular embodiment, the solid is magnetite iron ore, in particular magnetite iron ore fines after beneficiation. Instead of biochar and iron ore, the solids can also be biochar fines produced during the production and preparation of biochar for use in the silicon production process. In a further embodiment, silica may be added to form a crude composite material so that the silica in the final composite product is in intimate contact with the carbon to facilitate its reduction to form silicon in an electric arc furnace. The mixing may be carried out at room temperature. In this particular example, mixing is performed to form the desired shape. The crude composite material may be formed by extrusion.

The crude composite material is then heated in step 108 to a temperature at which the bio-oil hardens through complex physical and chemical processes. The bond between the C-containing component (including the reaction products from the bio-oil) and the magnetite ore includes physical forces and chemical bonds.

In step 110, the volatiles released by the reactions involving the bio-oil are recovered to extract their energy values. They can also be used as chemical feeds for other chemical processes.

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Claims

1. A method of producing a solid composite material, the method comprising:

providing a biomeal formed from the thermal treatment of a carbonaceous feed comprising biomass, the biomeal being capable of hardening at an elevated temperature;

mixing the biomeal with a solid or paste to form a raw composite; and

2. The method of claim 1, wherein the biomeal is formed by pyrolysis or hydrothermal treatment or liquefaction or other thermal treatment of a carbonaceous feed comprising biomass.

3. The method of claim 1 or claim 2, wherein the biomeal comprises a flowable liquid or a non-flowable paste.

4. The method of any one of the preceding claims, wherein the solid or paste is a mineral.

5. The method of claim 4, wherein the mineral is iron ore.

6. The method of claim 5, wherein the composite material forms a portion of a blast furnace feed.

7. The method of any one of claims 1 to 3, wherein the solid or paste is a carbon material.

8. The process of claim 7 wherein the solid is metallurgical coke fines.

9. The method of claim 7, wherein the solid is biochar.

10. The method of any preceding claim 7 to 9, wherein the solid also comprises silica.

11. The method of any preceding claim 7 to 10, wherein the composite material forms part of an electric arc furnace feed.

12. The method of any one of the preceding claims, further comprising the steps of providing biochar formed from the thermal treatment of a carbonaceous feed comprising biomass and mixing the biochar with the biomeal and the solids to form a crude composite material.

13. The method according to any one of the preceding claims, further comprising the step of recovering volatiles and other gases released by the heating of the crude composite material.

14. The method of claim 13, wherein the recovered volatiles and other gases are combusted to provide energy to heat the crude composite.

15. The method of claim 13, wherein the recovered volatiles and other gases are used to generate electricity.

16. The method of any one of the preceding claims, wherein the step of heating the crude composite material is performed in a stepwise manner.

17. The method according to any one of the preceding claims, wherein the step of heating the raw composite material is performed so as to at least partially melt or sinter and/or carbonize the composite material.

18. The method of any one of the preceding claims, wherein the step of heating the raw composite material is performed by heating the raw composite material to combust organic components in the raw composite material.

19. The method according to any one of the preceding claims, further comprising the step of providing a catalyst to increase the rate of hardening of the crude composite material.