CN112424317B

CN112424317B - Method and system for reactive distillation of biological crude oil

Info

Publication number: CN112424317B
Application number: CN201980047051.0A
Authority: CN
Inventors: 李春柱; R·古纳万; Z·王; S·王; L·张; M·M·海森; H·王
Original assignee: Renergi Pty Ltd
Current assignee: Renergi Pty Ltd
Priority date: 2018-05-14
Filing date: 2019-05-14
Publication date: 2023-07-14
Anticipated expiration: 2039-05-14
Also published as: CN112424317A; AU2019268408A1; WO2019218007A1

Abstract

The present disclosure provides methods and systems for reactive distillation of biocrude formed by heat treatment of carbonaceous feedstock including biomass. First, the bio-crude is heated under elevated pressure. Next, the partial pressure of the material resulting from the chemical reaction of the bio-crude is reduced such that the bio-crude is distilled to form different fractions. Reactive distillation can be integrated with further upgrading and utilization of the bio-crude. For the integration of reactive distillation of bio-crude with hydrotreating or reforming of bio-crude, two examples are given.

Description

Method and system for reactive distillation of biological crude oil

Technical Field

The present invention relates to a method and a system for reactive distillation of bio-crude, in particular reactive distillation of bio-oil at elevated pressure. The invention also relates to the integration of reactive distillation of bio-crude with further upgrading/utilization of bio-crude.

Background

Biomass is the only renewable resource containing carbon that can be directly used to produce liquid fuels, chemicals, and carbon materials. Among the various pathways of biomass conversion, thermochemical conversion offers many advantages from the standpoint of process yield and efficiency. Pyrolysis and hydrothermal liquefaction of biomass have attracted considerable attention worldwide, particularly for the production of liquid fuels and chemicals.

Pyrolysis of biomass will produce three main classes of products, including liquid products known as bio-oils, solid products known as biocarbons, and gaseous products including various flammable and non-flammable gases. There are many different pyrolysis techniques and one such technique is the abrasive pyrolysis of biomass disclosed in PCT/AU 2011/000741. Bio-oils are a class of bio-crude oils and can be bio-refined/upgraded into various liquid fuels and chemicals (e.g., using the techniques disclosed in PCT/AU 2013/000825) as well as solid carbon materials (e.g., using the techniques disclosed in PCT/AU 2016/000133).

When biomass is heated to elevated temperatures, bio-oils have very complex physical and chemical structural features as a product from (partial) disruption of biopolymers and other substances in biomass. For example, the materials in bio-oils can have a very broad range of molecular mass distributions, ranging from small molecules, such as water to partially degraded biopolymers of cellulose, hemicellulose and lignin. The materials in the bio-oil may have various chemical structures including, but not limited to, aliphatic, cycloaliphatic, hydro-aromatic, heteroaromatic, and aromatic structures having abundant functional groups such as carboxylic acid groups, carbonyl groups, and phenolic groups. Although oxygen-containing structures (e.g., furan type structures) and functional groups are very abundant in biological oils, various organic structures containing nitrogen and/or sulfur may also be present in biological oils. Therefore, bio-oils are very reactive. Various inorganic substances such as potassium, sodium, magnesium, calcium and various trace elements, which are macro-and micro-inorganic nutrients for the growth of biomass, may also be partially volatilized during pyrolysis and become part of the bio-oil.

While bio-oils are commonly referred to as liquids, bio-oils may also have a colloidal structure and properties.

Biochar fines and other particulates (e.g., soil derived from biomass feed for pyrolysis) may also be present in the bio-oil.

Biological crude oil from the hydrothermal liquefaction of biomass or other means of thermochemical conversion of biomass has many of the characteristics described above for biological oils.

In developing new technologies for upgrading or directly utilizing bio-crude, the complex nature and structural features of bio-crude must be fully considered. For example, when bio-oil is hydrotreated to produce liquid fuels and chemicals, lighter materials in bio-oil can have very different behaviors than corresponding heavier materials. Ideally, they should be hydrotreated under very different conditions.

Similarly, the lighter fraction and the heavier fraction are significantly different during reforming and have different optimal reforming conditions.

In addition, heavier materials may also have different beneficial uses than lighter materials. For example, heavier materials may be more suitable than lighter materials as feeds for producing solid carbon materials.

Still further, the inorganics or particulates in the bio-oil may adversely affect the optimal performance of the bio-oil upgrading or utilization process and should be separated from the bio-oil prior to upgrading or utilizing the bio-oil.

Therefore, it is desirable to separate the bio-oil into various fractions, for example based on their volatility or boiling point (more practical boiling point range), simultaneously with the removal of inorganic matter and particulates. Distillation appears to be a suitable way of performing such separation. However, due to the high reactivity of bio-oils, excessive coke formation is a major problem when bio-oils are distilled using prior art techniques at ambient or reduced (vacuum distillation) pressures. New techniques for separating biological crude oil, for example, into fractions via distillation, and minimizing coke formation are necessary.

Disclosure of Invention

According to a first aspect of the present invention there is provided a process for the reactive distillation of a biological crude oil, the process comprising:

providing a biocrude formed by heat treating a carbonaceous feedstock comprising biomass;

heating the bio-crude at an elevated pressure; and

the partial pressure of the material initially present in the bio-crude and formed by the reaction of the bio-crude is reduced such that the material distills to form different fractions.

As used herein, the term "biomass" refers to any material derived from a living or recently living organism, including material excreted from or by an organism. Examples include, but are not limited to, plant-derived lignocellulosic material and animal-derived manure.

As the term is used herein, "carbonaceous feed" is intended to include various renewable feeds containing carbon and non-renewable feeds including, but not limited to, coal (its full coalification grade spectrum), biomass, solid waste, or mixtures thereof. The solid waste may include, but is not limited to, agricultural waste, forestry waste, industrial waste, domestic/municipal waste, or residues from the processing of carbonaceous feedstocks. These wastes may also be mixed into carbonaceous feed. In fact, in a broad sense, many solid wastes are considered biomass. Alternatively, biomass is at least an important component of many solid wastes.

As used herein, the term "heat treatment" is intended to include within its scope any process at elevated temperature in the presence or absence of additional substances. For example, pyrolysis of biomass under an inert, oxidizing or reducing atmosphere is a heat treatment process. Hydrothermal treatment of aquatic biomass (in subcritical or supercritical state or at critical point) is another type of heat treatment process.

As used herein, the term "bio-crude" is intended to include any liquid or paste/slurry product from the heat treatment of biomass or other carbonaceous feedstock. Bio-oils from the pyrolysis of biomass are typical bio-crude oils. The bio-crude may include various impurities including, but not limited to, dissolved inorganics and particulates. The particulates may contain organic carbon (e.g., biochar fines) or may be common organics (e.g., soil in the feed that includes biomass that is ultimately in biocrude).

In an embodiment, the bio-crude is a bio-oil from pyrolysis of a carbonaceous feed comprising biomass. In a further particular embodiment, the bio-crude is a bio-oil from pyrolysis of biomass. In another embodiment, the bio-crude is a product from the hydrothermal liquefaction of a carbonaceous feedstock comprising biomass or a product from the hydrothermal liquefaction of biomass.

The term "elevated pressure" refers to a pressure level that is higher than ambient pressure. Similarly, the term "elevated temperature" refers to a temperature level that is higher than ambient temperature.

As used herein, the term "distillation" is intended to include within its scope any process in which components (or materials) in a feed for distillation are separated into various fractions having different boiling point ranges or other properties. The boiling point ranges for the various fractions may overlap each other. After separation, these fractions may be in the form of vapors (gases), supercritical fluids, liquids, solids, or mixtures thereof, such as pastes, slurries, and composites. As used herein, the term "reactive distillation" is intended to include any distillation process in which at least one type of chemical reaction occurs.

Distillation of bio-crude typically involves chemical reactions due to the high reactivity of the bio-crude. Therefore, distillation of biological crude oil is typically a reactive distillation process. In fact, biological oils, even though they are stored under ambient conditions, can undergo complex chemical reactions, albeit slowly. In particular, heating the bio-crude to an elevated temperature may cause a network of chemical reactions to occur in the bio-crude, forming lighter and heavier materials. For example, distillation of bio-oil to a temperature above 150 ℃ at a pressure near atmospheric pressure may allow formation of fumes and solid residues due to the reaction.

Embodiments of the present invention have significant advantages. In particular, heating the bio-crude (e.g., bio-oil) under pressure greatly reduces the formation of coke or heavy materials as compared to heating the same bio-crude to the same temperature at a low pressure, such as at atmospheric pressure or at a reduced pressure (under vacuum).

Without being bound by any particular theory, a number of benefits may be realized by heating the bio-crude at elevated pressure. For example, many chemicals in biological oils are polar, mainly due to the presence of various oxygen-containing structures in biological oils. Water, which often occupies 15 to 35wt% of the bio-oil, plays an important role in dissolving various substances in the bio-oil, helping to keep the bio-oil as a liquid or liquid-like material. Interactions between water and other bio-oil components include not only van der waals forces but also other interactions such as H-bonds. These forces are also at least partially responsible for the 3-D structural configuration of macromolecules in biological oils. Other light materials in the bio-oil also contribute to the dissolution of heavy materials in the same bio-oil. When the bio-oil is heated at low pressure, e.g., near atmospheric pressure or under some vacuum, water and some light materials in the bio-oil will readily evaporate, leaving behind a viscous liquid or solid. However, when the bio-oil is heated under elevated pressure, evaporation of water and light materials will be greatly hindered or inhibited. The presence of water and light materials will also dilute the heavy materials, helping to slow down the recombination reaction responsible for forming additional heavier materials. Many other reactions may also be carried out at elevated pressures. For example, acids (e.g., formic acid and acetic acid) in biological oils can catalyze hydrolysis reactions that will help reduce the formation of heavy materials. In contrast, evaporation of water and light acids during distillation at low pressure will make these reactions, such as hydrolysis, very difficult or impossible.

The saturated vapor pressure of a material (including a mixture) is a function of temperature. With embodiments of the present invention, it is difficult to set a fixed pressure value for reactive distillation of bio-crude. The higher the pressure, the smaller the amount of bio-crude component will be evaporated. The distillation pressure at which the bio-crude is heated can advantageously be maintained at a level higher than the saturated vapor of the bio-crude at any temperature to which the bio-crude is heated.

The step of heating the bio-crude at an elevated pressure may be performed in various ways. In one embodiment, the bio-crude is heated at an elevated pressure created by the vapor of the bio-crude itself. For example, bio-crude may be heated at elevated pressure by limiting the space available in a closed vessel (autoclave) for evaporation and escape of vapors from the heated bio-crude.

In another embodiment, the bio-crude is heated at an elevated pressure created by a pressurized fluid surrounding the bio-crude but having low solubility in the bio-crude liquid. The fluid may be an inert gas or other gas, including mixtures thereof.

In further embodiments, the bio-crude is heated at an elevated pressure created by a combination of a pressurized fluid and a confined space that delays volatilization of components from the bio-crude.

When reactive distillation of bio-crude is integrated with other means of bio-crude upgrading/utilization, it is contemplated that distillation pressure be set at a level higher or closer than the upgrading/utilization process. For example, when reactive distillation is integrated with the hydrotreating of a bio-crude (see below for more details), the distillation may be performed at a pressure higher or near that of the hydrotreating.

The peak temperature of the biological crude being distilled is an important factor affecting the degree of separation to be achieved from the reactive distillation. This may be selected and set according to the desired product to be obtained from the distillation. In a particular embodiment, in order to achieve a good yield of light substances from bio-oil, the peak temperature for distillation of bio-oil is set to a level preferably between 100 ℃ and 300 ℃, more preferably between 150 ℃ and 270 ℃, even more preferably between 150 ℃ and 230 ℃ and most preferably between 150 ℃ and 210 ℃ when the operating pressure is about 7 MPa.

The peak temperature is selected based on the volatility of the substances present in the biocrude to be distilled and the extent of the reaction to be achieved. In one embodiment, the peak temperature is set low (< 150 ℃) in order to minimize chemical reactions. Only very light materials will distill from the bio-crude. In another embodiment, the peak temperature is set at a moderate level (e.g., <230 ℃) for some of the very reactive species to be reacted. In yet another embodiment, the peak temperature is set higher (e.g., up to 450 °) such that the bio-crude undergoes strong reactions, including but not limited to cracking reactions and polymerization reactions, such that a solid residue is formed, and the remaining portion of the bio-crude is distilled off.

Once the bio-crude reaches the desired peak temperature, the partial pressure of the material originally present in and/or derived from the bio-crude may be reduced to allow distillation to proceed. This can be achieved in many ways. In one embodiment, the overall system pressure is reduced such that the partial pressure of all materials originally present in and/or derived from the bio-crude is reduced. This is typically accompanied by a decrease in temperature, which may require a device to supply the thermal energy required for the evaporation (latent heat) of the volatile material.

In another embodiment, another fluid is mixed with the hot bio-crude and its reaction products such that the partial pressure of all substances initially present in and/or derived from the bio-crude is reduced. The exact choice of fluid will depend on the purpose of the reactive distillation. In one aspect, the fluid is preferably a gas and more preferably an inert gas. On the other hand, the reactive fluid preferably undergoes some beneficial reaction with the bio-crude component. Furthermore, evaporation of volatile materials may cause the system temperature to drop, and thus a means of supplying heat to satisfy the heat of evaporation may be required.

The volatilized material may condense into various fractions having different boiling point ranges, but the boiling point ranges of these fractions may overlap one another. In one embodiment, the condensation may be performed in multiple steps/stages, as in conventional distillation columns known to those skilled in the art. In alternative embodiments, the condensable volatiles may be condensed into a fraction. The product fraction may be a gas (vapor), liquid, solid or mixtures/composites thereof, such as slurries and And (5) paste. For example, lighter materials and thus products may be formed due to reactions occurring during distillation, as part of which may be materials containing such as CO ₂ And CH (CH) ₄ In gaseous (vapor) form.

According to a second aspect of the present invention there is provided a process for the reactive distillation of a biological crude oil, the process comprising:

providing an additive capable of reacting with the bio-crude, catalyzing and/or inhibiting reactions involving the bio-crude and/or dissolving the bio-crude and/or its reaction products;

mixing the bio-crude and an additive to form a feed mixture;

heating the feed mixture at an elevated pressure; and

Although "catalytic" is generally meant to refer to the effect of accelerating the reaction, it also broadly includes the effect of slowing down, i.e. "suppressing", the reaction. In the same reaction mixture, the same catalyst may catalyze some reactions and inhibit others.

In an embodiment, the bio-crude is a bio-oil from pyrolysis of a carbonaceous feed comprising biomass. In a further particular embodiment, the bio-crude is a bio-oil from pyrolysis of biomass. In another embodiment, the bio-crude is a product from the hydrothermal liquefaction of a carbonaceous feedstock comprising biomass or the hydrothermal liquefaction of biomass.

In contrast to the first aspect of the invention, one purpose of introducing the additive in the second aspect of the invention is to react the bio-crude with the additive when the feed mixture is heated, either by catalyzing/initiating a new reaction between the bio-crude or by catalyzing/inhibiting an inherent reaction involving the bio-crude components at elevated temperatures. The additives may also perform the function of catalyzing/initiating new reactions and catalyzing/inhibiting reactions inherent to the biological crude oil component.

In one embodiment, the additive is methanol for reactive distillation of bio-oil from pyrolysis of biomass. Methanol may be in the form of a liquid (subcritical state), vapor, supercritical fluid, or at a critical point thereof. Methanol can initiate many reactions with bio-oil components. For example, methanol may react with carboxylic acid groups in the bio-oil to form esters, with carbonyl groups (e.g., aldehydes) in the bio-oil to form acetals, and with sugars (or oligomers) in the bio-oil to form products such as levulinic acid. Transesterification with methanol may also occur. Many other reactions may also occur, such as methanolysis of olefins. Methanol may also at least partially inhibit reactions associated with bio-oils that would form heavy materials or coke. These reactions between methanol and bio-oil components will help stabilize the bio-oil and reduce coke formation when the bio-oil is heated. Many reactions associated with methanol and bio-oil can be catalyzed by acidic components in the bio-oil or externally added acidic species.

In another embodiment, higher alcohols (e.g., ethanol, propanol, and butanol, or any mixture thereof) are used as additives.

The additive may also be a mixture. In a further embodiment, a mixture of alcohols including methanol and/or higher alcohols is used as additive.

In a particular embodiment, the additive mixture is a mixture of an alcohol (or alcohol mixture) and an acid, wherein the acid will act as a catalyst for the reaction between the alcohol and the bio-oil. In an alternative particular embodiment, the additive mixture is a mixture of an alcohol (or alcohol mixture) and a base, wherein the base will catalyze the reaction between the alcohol and the bio-oil.

Those skilled in the art will recognize that many different types of additives, catalysts, or mixtures thereof may be used to initiate/catalyze new reactions in the bio-crude and/or inhibit inherent reactions of the bio-crude at elevated temperatures and pressures without departing from the inventive essence of the present invention.

Another purpose of introducing the additive is for the additive to act as a solvent or as part of a solvent mixture. In particular, the additive is mainly used to dissolve heavy substances in the bio-crude and/or heavy substances formed from the bio-crude when heated. This is particularly useful for preventing the distillation system from clogging or reducing the degree and/or frequency of clogging. In a particular embodiment, the additive is acetone. During heating of the feed mixture, depending on the conditions of the reactive distillation, the acetone may be in the form of a liquid or supercritical fluid or at its critical point. Those skilled in the art will recognize that many types of solvents may be used for this purpose by taking into account the thermal stability, solubility, and other factors of the heavy materials, such as economics. Solubility is referred to herein as under conditions of distillation (temperature and pressure) and not necessarily under ambient conditions. Recovery of the solvent after distillation, and thus reuse of the solvent, is also contemplated.

In embodiments of the first or second aspects of the invention, one or more of the heavier fractions are further heat treated to produce additional lighter products.

In another embodiment of the first or second aspect of the invention, one or more heavier fractions are used as fuel. In a further embodiment, these heavier fractions are blended with additional substances to modify their properties, such as viscosity.

It is also desirable to integrate such bio-oil separation processes into overall bio-oil upgrading or utilization processes for optimal performance and efficiency. For example, and without limiting the scope of the invention, for a bio-crude to be hydrotreated, the bio-crude must be heated to an elevated temperature at which the hydrotreating reaction takes place, which requires a significant amount of energy. The presence of water in the bio-crude (e.g., water in the bio-oil) means that in many hydrotreating processes, a significant amount of energy may be required to evaporate the water in addition to the bio-crude material. It may be very advantageous to separate and remove very heavy substances, inorganic substances and particulates from the bio-crude prior to the hydrotreating. Therefore, innovation is needed to distill bio-crude with minimized coke formation and integrate distillation into the overall bio-crude upgrading or utilization process. Integration of bio-crude distillation with bio-crude hydrotreating is one such example. Integration of bio-crude distillation with bio-crude reforming is another such example.

According to a third aspect of the present invention there is provided a process for the reactive distillation of a biological crude oil, the process comprising:

heating the bio-crude at an elevated pressure;

lowering the partial pressure of the material initially present in the bio-crude and formed by the reaction of the bio-crude such that the material distills to form a different fraction; and

one or more of the fractions is hydrotreated with a hydrogenating reagent to produce a hydrotreated product.

The term "hydrotreating" or variants such as "hydrotreating" and "hydrotreating" as used herein refers to any reaction between a bio-crude and a hydrogenating agent, including but not limited to hydrogenation, hydrocracking, hydrodeoxygenation, hydrodesulfurization, and hydrodenitrogenation. These reactions may be catalytic or non-catalytic.

In an embodiment, the bio-crude is a bio-oil from pyrolysis of a carbonaceous feed comprising biomass. In a further particular embodiment, the bio-crude is a bio-oil from pyrolysis of biomass. In another embodiment, the bio-crude is a product from the hydrothermal liquefaction of a carbonaceous feed comprising biomass or a product from the hydrothermal liquefaction of biomass.

According to a fourth aspect of the present invention there is provided a process for the reactive distillation of a biological crude oil, the process comprising:

providing an additive capable of reacting with the bio-crude;

mixing the bio-crude and an additive to form a feed mixture;

heating the feed mixture at an elevated pressure; and

hydrotreating one or more fractions to produce a hydrotreated product.

In an embodiment of both the third and fourth aspects of the invention, the hydrogenation reagent is hydrogen.

The third and fourth aspects of the invention introduce the further step of hydrotreating one or more fractions from the reactive distillation of the bio-crude as compared to the first and second aspects of the invention, respectively. Embodiments of the present invention provide a beneficial integration of reactive distillation with upgrading of bio-crude, where hydrotreating is an example of an upgrading process. This may have significant advantages over direct upgrading (hydrotreating) of bio-crude, which will be explained below using bio-oil as an example of bio-crude:

(a) In a preferred embodiment, the hydrogen gas used for the hydrotreatment can be used as a fluid to reduce the partial pressure of the material originally present in and/or derived from the bio-crude to effect distillation.

(b) The bio-oil may contain inorganic substances (e.g., K salts or carboxylates, mg salts or carboxylates, and Ca salts or carboxylates) and particulates (including biochar fines). These inorganics and particulates can adversely affect the hydrotreating process, for example, by plugging the catalyst bed or poisoning the catalyst. These inorganics and particulates have very limited volatility and can be effectively separated from the bio-oil during reactive distillation of the bio-oil. In a preferred embodiment, the hydrotreatment of the organic components of the bio-oil is performed without the side effects of these organics and particulates.

(c) The heavy and light materials of the bio-oil can be distilled into different fractions and hydrotreated separately under their optimal hydrotreating conditions. In one embodiment, the bio-oil is distilled into two fractions: the heavier fractions include very heavy organics, inorganics, and particulates, and the lighter fractions contain lighter materials of the bio-oil. The lighter fraction may be hydrotreated under very different conditions than those used for the heavy fraction. In alternative embodiments, only the lighter fraction is hydrotreated and the heavier fraction is to be recovered for other purposes.

(d) In a preferred embodiment, the fraction to be hydrotreated is fed directly to the hydrotreating reactor in its vapor form without condensation. This means that the heat required to heat the bio-oil and to evaporate the water and organics can be supplied during reactive distillation, reducing the heat requirement at the inlet of the hydrotreating reactor, allowing the bio-crude vapor fraction to be hydrotreated according to the hydrotreating technique disclosed in PCT/AU2013/000825 to be rapidly heated to the hydrotreating reaction temperature in the presence of hydrotreating catalyst, minimizing coke formation.

(e) In embodiments, an alcohol (e.g., methanol) is added to the bio-oil during distillation. The alcohol effectively reacts with many reactive functional groups in the bio-oil to stabilize the bio-oil. Stabilization of the bio-oil helps reduce coke formation during hydrotreating.

(f) In further embodiments, the reactive distillation may be further integrated with the hydrotreating. As an example, the lighter fraction and the heavier fraction are separated in a corresponding hydrotreating reactor which hydrotreats at least one separated fraction, wherein the initial section of the hydrotreating reactor performs the separation function.

In an embodiment of the third or fourth aspect of the invention, the system further comprises one or more reactors in which the one or more heavier fractions are further heat treated to produce an additional lighter product which is further hydrotreated.

According to a fifth aspect of the present invention there is provided a process for the reactive distillation of a biological crude oil, the process comprising:

heating the bio-crude at an elevated pressure;

one or more of the fractions are reformed to produce a reformed product.

As used herein, the term "reforming" refers to the reaction of a biological crude or fraction thereof, by their reaction with a reforming agent, to convert into lighter products, typically gases. Mainly comprises CO and H ₂ Is typically the target product. The reforming agent may be steam, air, oxygen, carbon dioxide, hydrogen, or a mixture containing any two or more thereof.

According to a sixth aspect of the present invention there is provided a process for the reactive distillation of a biological crude oil, the process comprising:

providing an additive capable of reacting with the bio-crude;

mixing the bio-crude and an additive to form a feed mixture;

heating the feed mixture at an elevated pressure; and

one or more of the fractions are reformed to produce a reformed product.

By removing inorganic, particulate and very heavy materials via reactive distillation of the bio-crude, a number of beneficial results can be achieved during reforming, including reduced coke formation, reduced catalyst poisoning (if used in a catalytic reforming process), and reduced catalyst bed plugging, as well as increased product quality.

The third to sixth aspects of the present invention are merely examples for integrating reactive distillation with further upgrading or utilization of bio-crude. In addition to hydrotreating and reforming, which are used as examples in the third to sixth aspects of the invention, the reactive distillation of the invention may be integrated with many other ways of upgrading and utilizing biological crude oil, which will be within the scope of the invention.

According to a seventh aspect of the present invention there is provided a system for reactive distillation of a bio-crude, the system comprising:

at least one inlet for feeding a biocrude oil formed by heat treating a carbonaceous feed comprising biomass into a distillation reactor capable of being pressurized;

a heat source and means for heating the bio-crude at an elevated pressure in the distillation reactor to form a product mixture comprising reaction products and unreacted components;

at least one outlet for allowing the product mixture to leave the distillation reactor for entry into the evaporation vessel;

means for reducing the partial pressure of the components in the product mixture such that the volatile materials in the product mixture evaporate to form one or more condensed and vapor phases.

The distillation reactor may take various shapes. In one embodiment, the distillation reactor is a coil or series of coils. The coil or series of coils is advantageous from the standpoint of providing a large amount of heat transfer area to heat the bio-crude at elevated pressure inside the distillation reactor.

Heat may be provided to the distillation reactor in various ways. In one embodiment, a coil or series of coils is immersed in a heating medium. In one embodiment, the heating medium may be a fluid in which the distillation reactor (e.g., coil or series of coils) is immersed, such as in a heat exchanger. In another embodiment, the heating medium is a bed (bath) of fluidized sand in which a distillation reactor (e.g., a coil or series of coils) is immersed.

In one embodiment, the partial pressure of the components in the product mixture is reduced using a pressure let down valve or orifice through which the product flows in a controlled manner. The degree of pressure reduction is controlled by the amount the blow-off valve is opened or the size of the orifice. In particular embodiments, a pressure let down valve or orifice is installed between the distillation reactor and the vaporization vessel.

In another embodiment, an additional fluid is introduced, the additional fluid is mixed with the product mixture and the product mixture is diluted to reduce the partial pressure of the components in the product mixture. In this case, the system further comprises a further inlet and/or a mixer. In particular embodiments, the additional fluid is a gas.

Upon lowering the partial pressure of the components in the product mixture, the volatile compounds will evaporate in the evaporation vessel. Evaporation is typically an endothermic process. It is advantageous to supply heat to the evaporation vessel. The evaporation vessel may take various shapes. In one embodiment, the vaporization vessel is a coil or a series of coils. The coil or series of coils advantageously provides a large heat transfer surface area to supply heat into the vaporization vessel. The amount of heat to be supplied will depend on the degree of separation to be achieved. Higher vaporization vessel temperatures will tend to vaporize more components than lower vaporization vessel temperatures.

In a further embodiment, the distillation reactor and the vaporization vessel are the same vessel. In this case, the distillation reactor may not have a separate physical outlet. In particular embodiments in which the distillation reactor is a coil, additional fluid is introduced into the coil at a point downstream of the inlet of the coil. The introduction of additional fluid divides the coil into two sections: the first portion of the coil serves as a distillation reactor and the second portion serves as an evaporation vessel. There may be more than one such point to introduce additional fluid.

In some applications, it may be sufficient to distill the bio-crude into a condensed phase and a vapor phase in the evaporation vessel. Of course, the system may further comprise means for cooling and condensing the volatile phase. In other applications, it may be necessary to produce a fraction having a narrower boiling point range (when condensed) than the volatile phase initially produced in the vaporization vessel. For this reason, the system further comprises means for cooling and condensing the volatile phase into more than one fraction. In a particular embodiment, the volatile phase initially formed undergoes progressive cooling and condensation for collecting the condensate into different fractions having different boiling ranges. Those skilled in the art of distillation will recognize that various means, such as distillation columns, and corresponding cooling means, may be used for this purpose. These also include corresponding means for effecting reflux to improve separation efficiency.

According to an eighth aspect of the present invention there is provided a system for reactively distilling a biological crude oil, the system comprising:

at least one inlet for feeding a mixture comprising bio-crude formed by heat treating a carbonaceous feed comprising biomass and an additive into a distillation reactor capable of being pressurized;

According to a ninth aspect of the present invention there is provided a system for reactive distillation of a biological crude oil, the system comprising:

at least one further inlet for feeding an additive into the distillation reactor;

The eighth and ninth aspects of the invention differ from the seventh aspect mainly in that the additive is fed into the distillation reactor. The additives may perform any or all of the following functions:

(a) When the bio-crude is heated at an elevated pressure in the distillation reactor, a new reaction of the components in the bio-crude is initiated and participated,

(b) Catalyzing and/or inhibiting intrinsic reactions associated with the bio-crude when heated at elevated pressure in the distillation reactor, and/or

(c) Dissolving (acting as a solvent) in the distillation reactor the heavy substances present in and/or formed by the components in the bio-crude.

In various embodiments, the additive is a mixture of more than one chemical compound.

The ninth aspect of the invention differs from the eighth aspect in that the additive is not mixed with the bio-crude before the additive and the bio-crude are fed into the distillation reactor, and in that the inlet for the additive may be further downstream of the inlet for the bio-crude, or vice versa.

The description relating to the seventh aspect and the related embodiments relating to the seventh aspect are also applicable to the eighth and ninth aspects of the present invention.

In an embodiment of any of the seventh to ninth aspects of the invention, the system further comprises a reactor in which one or more heavier fractions are fed for heat treatment to produce an additional lighter product.

According to a tenth aspect of the present invention there is provided a system for reactive distillation of a bio-crude, the system comprising:

means for reducing the partial pressure of the components in the product mixture so that the volatile materials in the product mixture evaporate to form different fractions;

means for feeding at least one of said fractions into a hydrotreating reactor containing a hydrotreating catalyst for hydrotreating therein to form a hydrotreated product, and

The hydrotreating reactor has means for receiving at least one hydrogenating reagent and at least one outlet for discharging hydrotreated products and unconverted hydrotreating reactants.

According to an eleventh aspect of the present invention there is provided a system for reactive distillation of a biological crude oil, the system comprising:

According to a twelfth aspect of the present invention there is provided a system for reactive distillation of a biological crude oil, the system comprising:

In a preferred embodiment of any of the tenth to twelfth aspects of the invention, the system further comprises at least one means to heat the fraction in the hydrotreating reactor only when the fraction contacts a hydrotreating catalyst which has been heated to a hydrotreating reaction temperature at which the catalyst is capable of providing activated hydrogen for the hydrotreating reaction to occur. In a further preferred embodiment, the fraction to be hydrotreated is heated by mixing the fraction with a heat stream of a hydrogenating reagent which may be hydrogen.

In an embodiment of any of the tenth to twelfth aspects of the invention, the means for receiving the hydrogenating reagent into the hydrotreating reactor is the same inlet for the fraction to be hydrotreated, wherein the fraction and the hydrogenating reagent are rapidly mixed. In an alternative embodiment, the means for receiving the hydrogenating reagent into the hydrotreating reactor is different from the inlet for the fraction to be hydrotreated.

In an embodiment of any of the eleventh and twelfth aspects of the invention, the additive, which may be a single compound or a mixture, performs any or all of the functions of reacting with the bio-crude during distillation, catalyzing/inhibiting the reaction of the bio-crude or dissolving the bio-crude and/or its reaction products. In a further embodiment, the additive participates in the hydrotreating reaction during the hydrotreating.

In an embodiment of any of the tenth to twelfth aspects of the invention, the lowering of the partial pressure of the components in the product mixture is achieved with any one or a combination of a pressure let down valve and the introduction of a further fluid. Importantly, in a preferred embodiment, the additional fluid is a hydrogenation reagent. The hydrogenation reagent may be hydrogen.

In embodiments of any of the tenth to twelfth aspects of the invention, each system may further comprise one or more hydrotreating reactors for hydrotreating of other fractions formed during distillation.

In further embodiments of any of the tenth to twelfth aspects of the invention, each system may further comprise means for cooling and condensing the volatile phase into more than one fraction and means for moving each fraction into a different hydrotreating reactor in which it is to be hydrotreated.

In still further embodiments of any of the tenth to twelfth aspects of the invention, the hydrogenation reagent comprises one or more H-donating compounds that can provide activated hydrogen in the hydrotreating reactor. In a further particular embodiment, the hydrogenation reagent comprises one or more compounds capable of generating free radicals to stabilize the broken bonds in the hydrotreating reactor. In particular embodiments, the hydrogenation reagent comprises recovered hydrotreated product. In a further particular embodiment, the hydrogenation reagent comprises hydrogen.

In a still further embodiment of any of the tenth to twelfth aspects of the invention, the lighter fraction and the heavier fraction are separated in a corresponding hydrotreating reactor in which the at least one separated fraction is hydrotreated, wherein the initial section of the hydrotreating reactor performs a separation function.

In an even further embodiment of any of the tenth to twelfth aspects of the invention, the system further comprises a reactor wherein one or more heavier fractions are fed for heat treatment to produce an additional lighter product which is further hydrotreated.

In an embodiment of any of the tenth to twelfth aspects of the invention, the bio-crude is bio-oil from pyrolysis of a carbonaceous feed comprising biomass. In a further particular embodiment, the bio-crude is a bio-oil from pyrolysis of biomass. In another embodiment, the bio-crude is a product from the hydrothermal liquefaction of a carbonaceous feed comprising biomass or a product from the hydrothermal liquefaction of biomass.

According to a thirteenth aspect of the present invention, there is provided a system for reactive distillation of a bio-crude, the system comprising:

means for passing at least one of said fractions to be reformed into a reforming reactor for reforming therein to form a reformed product gas; and

a reforming reactor having at least one inlet for receiving at least one reforming reagent and at least one outlet for discharging reformate and unconverted reforming reactant.

According to a fourteenth aspect of the present invention there is provided a system for reactive distillation of a bio-crude, the system comprising:

According to a fifteenth aspect of the present invention there is provided a system for reactively distilling a bio-crude, the system comprising:

In an embodiment of any of the fourteenth and fifteenth aspects of the present invention, the additive, which may be a single compound or a mixture, performs any or all of the functions of reacting with the bio-crude, catalyzing/inhibiting the reaction of the bio-crude, dissolving the bio-crude and/or its reaction products during distillation, or participating in a reforming reaction during reforming.

In an embodiment of any of the thirteenth to fifteenth aspects of the invention, reducing the partial pressure of the components in the product mixture may be achieved with any one or a combination of a pressure let down valve and the introduction of additional fluid. Importantly, in a preferred embodiment, the additional fluid is part of a reforming agent that may comprise steam.

In an embodiment of any thirteenth to fifteenth aspects of the invention, the bio-crude is bio-oil from pyrolysis of a carbonaceous feedstock comprising biomass. In a further particular embodiment, the bio-crude is a bio-oil from pyrolysis of biomass. In another embodiment, the bio-crude is a product from the hydrothermal liquefaction of a carbonaceous feed comprising biomass or a product from the hydrothermal liquefaction of biomass.

In an embodiment of any of the thirteenth to fifteenth aspects of the present invention, the reforming reagent is H ₂ O (steam), CO ₂ Air, oxygen or H ₂ One or more of the following.

In a further embodiment of any of the thirteenth to fifteenth aspects of the invention, the system further comprises one or more reforming reactors for reforming other fractions formed during distillation. This allows different distillate fractions to be reformed under different conditions.

Drawings

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

FIG. 1 is a flow chart of a method and system for reactive distillation of a bio-crude in accordance with an embodiment of the present invention;

FIG. 2 is a flow chart of a method and system for reactive distillation of a bio-crude in accordance with another embodiment of the present invention;

FIG. 3 is a flow chart of a method and system for reactive distillation of a bio-crude in accordance with a further embodiment of the present invention; and

fig. 4 is a flow chart of a method and system for reactive distillation of bio-crude according to still further embodiments of the present invention.

Detailed Description

Embodiments of the present invention relate to methods and systems for reactive distillation of biological crude oil. It should be emphasized that the present invention may be practiced in either batch or continuous operation. Some example embodiments of the invention will be explained below, focusing particularly on continuous operation. However, the present invention is not limited to these embodiments.

Fig. 1 shows a method and system 100 for reactive distillation of a bio-crude to produce a lighter fraction and a heavier fraction. Biological oils from pyrolysis of biomass are used as biological crude oil to illustrate specific embodiments.

A number of pyrolysis techniques may be used to produce bio-oil from the pyrolysis of various biomass resources. In this embodiment, bio-oil is produced from the abrasive pyrolysis of eucalyptus dwarf biomass according to the techniques disclosed in PCT/AU 2011/000741.

The bio-oil 101 to be distilled is stored in a refillable tank 105. The high pressure pump 110 is used to feed the bio-oil 101 to the distillation reactor 125. Distillation reactor 125 can be pressurized. In one embodiment, it is pressurized to 7MPa when in use. The operating pressure can be within a wide range. Therefore, the distillation reactor 125 is preferably constructed using steel. In embodiments, distillation reactor 125 is made from a coil or series of coils. This has a significant advantage because the coil structure provides a large heat transfer surface area while it can sustain high pressures. In an alternative embodiment, a bank of tubes is used similar to the arrangement in a shell-and-tube exchanger.

Distillation reactor 125 is heated by immersion in a bath/bed 130 of fluidized sand. The fluidized sand bath 130 has the excellent ability to provide a relatively uniform temperature distribution inside the bed. As the bio-oil flows through distillation reactor 125, it will be indirectly heated by the sand. In an alternative embodiment, a bank of tubes is used as a distillation reactor and heated using a hot fluid in an arrangement similar to that in a shell-and-tube heat exchanger.

As will be explained later, the back pressure regulator 198 is used to maintain system pressure. As the bio-oil 101 is heated at an elevated pressure in the distillation reactor 125, reactions associated with the bio-oil will occur to form a product mixture comprising reaction products and unreacted components. The product mixture then exits distillation reactor 125 as stream 126.

In an embodiment, the additional fluid 135 is used to reduce the partial pressure of the components in the product mixture. Fluid 135 is supplied from a high pressure source and then its pressure is regulated to a desired pressure level with pressure regulator 140 before its flow rate is measured with flow metering device 145. The fluid 135 then enters the heater 150, which is a coil or series of coils 150, to be heated. In alternative embodiments, heater 150 may be a bank of tubes or any other suitable device. Coil 150 is heated by immersion in a fluidized sand bath (130) that also houses and heats distillation reactor 125. In an alternative embodiment, a separate tool (e.g., another fluidized sand bed or shell-and-tube heat exchanger) is used to heat the fluid 135. In one embodiment, the fluid is a gas. In a preferred embodiment, the fluid is hydrogen.

The heated fluid 135 exiting coil 150 mixes with the hot product mixture 126 exiting distillation reactor 125 to form a new stream 151 that then enters vaporization vessel 155. Upon mixing, the fluid 135 dilutes the product mixture 126 such that the partial pressure of the components therein decreases, so that upon mixing, some limited degree of evaporation may occur. However, by carefully controlling the conditions (especially for short periods of mixing), evaporation occurs mainly in the evaporation vessel 155. Evaporation is an endothermic process. In one embodiment, the vaporization vessel is shaped as a coil or series of coils 155 that are immersed in the fluidized sand bath 130 for heating. The fluidized sand bath for vaporization vessel 155, the fluidized sand bath for distillation reactor 125, and the fluidized sand bath for heater 150 may be the same or different. This arrangement effectively supplies heat for evaporation to maintain the evaporation operating temperature. In an alternative embodiment, the evaporation vessel is in the form of a row of tubes arranged like a shell-and-tube heat exchanger. The evaporation vessel may be any suitable device.

After evaporation in evaporation vessel 155, stream 156 exiting vessel 155 may comprise multiple phases, which then enter separator 160. Condensed phase 164 from separator 160 is discharged from valve 165 as stream 166, while the vapor phase exits separator 160 as stream 167. The temperature of the separator 160 needs to be well controlled. In one embodiment, the separator 160 is maintained at the same temperature as the vaporization vessel 155. In particular embodiments, distillation reactor 125, heater 150, vaporization vessel 155, and separator 160 are all immersed in the same fluidized sand bath 130. In another embodiment, the separator is maintained at a temperature different (e.g., lower) than the temperature of distillation vessel 155 using another fluidized sand bath or other tool.

In one embodiment, stream 167 is condensed together as a fraction (except for some minor amounts of uncondensed gaseous products and uncondensed components in stream 135). In another embodiment, stream 167 can undergo progressive cooling and condensation in separator 170, separator 180, and separator 190 to produce condensed products, and is discharged as stream 176, stream 186, and stream 196 via valve 175, valve 185, and valve 195, respectively. Many cooling tools known to those skilled in the art (details not shown in fig. 1) may be used.

Streams

177 and 187 are intermediate volatile streams. Stream 197 will contain uncondensed gaseous products and uncondensed components in stream 135. After passing through the back pressure regulator 198, the uncondensed material will be discharged from the system 100 as stream 199. Any reasonable number of separation stages may be present, suitable separators (e.g., 160, 170, 180, and 190) and inter-stage cooling (not shown) to produce product fractions (e.g., 166, 167, 176, 177, 186, 187, 196, and 197).

In further embodiments, the separator and inter-stage cooling may be replaced by a conventional distillation column known to those skilled in the art. When a pressure let down device (e.g., a valve) is used, the distillation column may be operated at various pressures.

Now back to distillation reactor 125. The use of a back pressure regulator 198 maintains the distillation reactor at an elevated pressure. Evaporation of the lighter materials is greatly hindered inside distillation reactor 125 (after heating in heater 150 before product stream 126 is mixed with stream 135), allowing the desired reaction between the lighter and heavier materials to occur.

In embodiments, the system 100 further comprises one or more reactors (not shown in fig. 1) into which one or more heavier fractions are fed for heat treatment to produce additional lighter products. The lighter products may be collected separately or in combination with any of

streams

167, 177, 187, and 197.

In some applications, the heavier fractions (any of

streams

166, 176, 186, and 196) may be used as fuel. Additional substances (e.g., methanol or other solvents) may be blended with the heavier fractions to alter fuel properties such as viscosity and ignition characteristics.

The system 100 also includes means for introducing the additive 114. In one embodiment, the additive 114 is pumped 120 from its refillable storage tank 115 to mix with the bio-oil 101 to form a feed mixture 123. Feed mixture 123 then enters distillation reactor 125.

The additives 114 may perform any or all of the following functions: as reactants for reaction with bio-oil, as catalysts/inhibitors for catalyzing/inhibiting the intrinsic reaction of bio-oil under elevated temperature and pressure conditions in distillation reactors, or as solvents for dissolving heavier materials present in distillation reactors.

The additive 114 may be a mixture of various materials that perform the above-mentioned functions.

In a further embodiment (not shown in fig. 1), additive 114 is introduced into the distillation reactor at a point downstream of the inlet of the distillation reactor.

In still further embodiments (not shown in fig. 1), the additive 114 is introduced after the distillation reactor, e.g., mixed with the product mixture 126.

In yet a further embodiment (not shown in fig. 1), additive 114 is introduced in any or all of the ways mentioned above: before distillation reactor 125, at a point downstream of the inlet of distillation reactor 125, and/or after the outlet of distillation reactor 125.

In a particular embodiment, additive 114 is methanol. In another particular embodiment, additive 114 is acetone. In a further embodiment, the additive is a mixture of acetone and methanol.

Fig. 2 shows a method and system 200 for reactive distillation of a bio-crude integrated with hydrotreating of a fraction to produce a lighter fraction and a heavier fraction. Biological oils from pyrolysis of biomass are used as biological crude oil to illustrate specific embodiments.

Many of the numbers in fig. 2 (method and system 200) are the same as those in fig. 1 (method and system 100) and have the same roles as those in system 100.

The lighter fraction 167 resulting from the reactive distillation of the bio-oil 101 is fed directly into a hydrotreating reactor 210 containing a catalyst 230 to produce a hydrotreated product stream 215. The catalyst 230 may be a mixture of catalysts. The hydrotreating reactor may contain different catalysts at different locations, for example in different stages along the direction of material flow in the reactor. In an embodiment, the hydrogenating reagent stream 220 is also fed to the hydrotreating reactor. In a particular embodiment, the hydrogenation reagent is hydrogen. In a further particular embodiment, stream 167 and stream 220 are rapidly mixed at the beginning of the cone forming the inlet section of the hydrotreating reactor 210. Many different hydrotreating techniques may be suitable, but particularly suitable hydrotreating techniques are those disclosed in PCT/AU 2013/000825.

Consistent with the teachings of PCT/AU2013/000825, lighter fraction 167 should be heated rapidly in the presence of catalyst 230, which catalyst 230 has already been at an elevated temperature and is effective to provide activated hydrogen. The elevated temperature referred to herein may be in the range of hydrotreating temperatures. To achieve rapid heating of stream 167, stream 220 is superheated, i.e., above the hydrotreating temperature, so that its thermal energy can be transferred to the materials in stream 167 as they mix in the presence of catalyst 230.

In another embodiment, stream 220 may be a mixture including, for example, hydrogen and other components. In a particular embodiment, the stream contains a hydrogen donating agent. In a further embodiment, the hydrogen donating agent is a hydrotreated product. For example, a portion of hydrotreated product stream 215 or stream 257 or a portion of stream 267 can be recovered (not shown in fig. 2) and become a portion of stream 220. For example, a hydrogen-donating agent containing a hydrogenated aromatic and/or cycloaliphatic can react with some of the components in stream 167 to supply activated hydrogen to the components in stream 167. For example, when mixed with stream 220, chemical bonds in components in stream 167 may break as the stream is heated, and/or while in hydrotreating reactor 210. The hydrogen donating agent in stream 220 can then supply activated hydrogen to stabilize the bond breaking (which can be part of the hydrotreating reaction) while the hydrogen donating agent is dehydrogenated. The dehydrogenated hydrogen donor reagent may then be rehydrogenated on the catalyst surface to continue the hydrogen donor process. In this way, the hydrogen donor reagent may act as a "hydrogen shuttle" to transfer hydrogen in the hydrogenation reagent, via the catalyst 230, to components in the stream 167 to be hydrotreated. The hydrogen shuttling process may be particularly useful for heavy molecules in stream 167 that have difficulty contacting active sites on/in the catalyst, especially active sites in the micropores of the catalyst, due to their size. Therefore, the hydrogen shuttle process can greatly help reduce coke formation, particularly in the hydrotreating reactor 210, due to heavy components in the bio-oil that have remained in stream 167.

Stream 220 may also contain materials that can react to produce other types of activating species, such as methyl radicals. These radicals may also stabilize broken bonds in the components of stream 167.

The additive 114 may be selected to be able to supply hydrogen or produce other activated species as described above.

The hydrotreating reaction is strongly exothermic, which can lead to a "slip" state in which the temperature in the hydrotreating reactor becomes very high and dangerous. This heat of reaction must be removed to maintain the reaction temperature within the desired range. In one embodiment, heat exchange means 235 is mounted inside the hydrotreating reactor. In a particular embodiment, the heat exchange means is a coil or series of coils 235 in a hydrotreating reactor. The heat exchange medium 240 flows through the coil 235, taking heat away. The heat exchange medium may enter from the upper inlet or the lower inlet. The heat exchange coil 235 also plays an important role in providing heat to the inlet section of the hydrotreating reactor to heat the incoming material in stream 167. In other words, the heat exchange coil 235 serves a dual role in providing heat in the initial section of the hydrotreatment reactor and removing heat in the later section (downstream) of the hydrotreatment reactor.

The hydrotreating reactor 210 may be placed vertically upward (fig. 2) or in any other orientation relative to the ground. For example, the hydrotreating reactor 210 may be placed upside down with the inlet in a lower position.

Hydrotreated product stream 215 is subjected to progressive cooling and condensation (250 and 260) to produce

different product fractions

256 and 266 that are discharged via valve 255 and valve 265. Stream 257 is the intermediate between the steps. The cooling and condensing may be performed in any number of steps (two steps are shown as examples in fig. 2). The back pressure regulator 278 is used to maintain system pressure. When some of stream 267 (in fig. 2) is vented (stream 279), the remainder may be recycled (not shown in fig. 2) to the hydrotreating reactor via stream 220. Recirculation may also operate from any or all of

streams

215, 257, or 267.

The heavier fraction 166 from the reactive distillation may also be hydrotreated in another hydrotreating reactor. Similarly, reactive distillation may have multiple steps of cooling and condensing (160, 170, 180, and 190 in fig. 1 as examples) to produce different fractions (166, 176, 186, and 196). All of these different fractions may be hydrotreated together or separately in different hydrotreating reactors. The present invention provides means for producing these fractions and means for hydrotreating these fractions in different hydrotreating reactors under conditions suitable for hydrotreating each fraction. In some particular embodiments, any of the

heavier fractions

166, 176, 186, and 196 can be heat treated in another reactor or reactors at higher temperatures to produce additional lighter products. The light product may then be hydrotreated.

Fig. 3 shows a method and system 201 for reactive distillation of a bio-crude integrated with hydrotreating of a fraction to produce a lighter fraction and a heavier fraction. Similar to system 200, bio-oil from pyrolysis of biomass is used as bio-crude to illustrate specific embodiments. The numbers in fig. 3 are the same as those in fig. 2 (method and system 200) and fig. 1 (method and system 100) and have the same uses as those in system 200 and system 100.

The main difference between system 201 and system 200 is that the lower section of hydrotreating reactor 210 also acts as a separator. In other words, the separator 160 in fig. 2 is integrated with the hydrotreating reactor 210 such that the separator 160 in fig. 2 becomes the lower section of the hydrotreating reactor 210 in fig. 3. Stream 220 enters hydrotreating reactor 210 from the bottom. In fig. 3, the reaction fluid flows upward in the hydrotreating reactor 210. Stream 156 exiting vessel 155 enters the bottom section of reactor 210. Stream 156 is mixed with stream 220, which may cause some of the material in stream 156 to further evaporate or condense. After mixing, stream 164 leaving reactor 210 contains a majority of the heavier materials in stream 156 which is discharged as stream 166 from valve 165, while the lighter materials contained in stream 156 flow upward in the hydrotreating reactor for hydrotreating therein. Product stream 215 exits hydrotreating reactor 210 from its top and enters unit 250. All downstream units (250, 256, 260, 266, and 278) and streams (256, 257, 266, 267, and 279) function the same as those of system 200 in fig. 2.

For

systems

200 and 201, there may be more than one hydrotreating reactor in series. In one embodiment, each hydrotreating reactor may have a bio-crude fraction feed (e.g., stream 167 in fig. 2 or stream 156 in fig. 3) produced from its own reactive distillation system using bio-crude (bio-oil 101), which is the same as defined by the numbers of 101 to 167 (fig. 2) or 101 to 156 (fig. 3). For the second hydrotreatment reactor or each further downstream hydrotreatment reactor, the hydrogenating reagent stream (e.g., 220) may include fresh hydrogenating reagent and a product stream (e.g., 215) from a preceding hydrotreatment reactor.

Fig. 4 shows a method and system 300 for reactive distillation of a biocrude to produce a lighter fraction and a heavier fraction integrated with reforming of the fraction to produce a synthesis gas product. Synthesis gas may also be used to produce hydrogen. Biological oils from pyrolysis of biomass are used as biological crude oil to illustrate specific embodiments.

Many of the numbers in fig. 4 (method and system 300) are the same as those in fig. 1 (method and system 100) and have the same purpose as those in method and system 100.

The lighter fraction 167 resulting from the reactive distillation of the bio-oil 101 passes through a pressure regulating device 310 to change its pressure to a level close to the desired operating pressure for the reformer 320 (to become stream 305). In one embodiment, reformer 320 is operated at a pressure near atmospheric (ambient) pressure.

Stream 305 is mixed with stream 330 containing reforming agent. In one embodiment, the reforming agent is a mixture of air and steam to effect an autothermal reforming operation. In a further embodiment, oxygen or oxygen enriched air is substituted for air to produce synthesis gas containing little nitrogen. In another embodiment, if a separate heat source is available to supply heat to reformer 320 (not shown in fig. 4), the reforming agent is steam. In all cases, CO ₂ And H ₂ It is also possible to reconstruct a part of the reagent mixture. The mixing of

streams

305 and 330 may be performed just before they enter reformer 320, at the inlet of reformer 320, or inside reformer 320.

The reforming reaction in reformer 320 is selected to convert as much organic components as possible in stream 305 (167) into synthesis gas (primary CO, H ₂ And CO ₂ ). If the synthesis gas is subsequently used to generate electricity, the light hydrocarbons such as CH in the synthesis gas are increased ₄ 、C ₂ H ₆ And C ₃ H ₈ Will be beneficial.

Reformer 320 may contain various catalysts.

Reformate stream 335 may contain various undesirable components,such as tarry materials, inorganic vapors (e.g., K volatilized from biomass during pyrolysis and present in bio-oil 101), and NO _x /SO _x And their precursors. An important advantage of the present invention is that inorganic vapors in stream 167 are minimized. It is often necessary or beneficial to remove these organic and inorganic impurities from reformate gas 335. Many different hot gas cleaning techniques may be used for this purpose, but the technique disclosed in PCT/AU2014/001135 is particularly advantageous for this purpose. In one embodiment, the hot gas cleaning is performed in two stages. In the first stage (340), the product gas stream 335 passes through a bed of coke or a bed of coke-laden catalyst, the product gas flowing in a direction perpendicular to the direction of flow of the coke catalyst (not shown). The key function of the first stage is to reform the tarry material to destroy impurities such as NH ₃ HCN and H ₂ S and remove any large particulates (if any). Stream 345 exiting the first stage enters the second stage (350) containing porous media. The key function of the second stage is to cool the product stream 345 to recover heat energy and condense the remaining organic and inorganic impurities on the porous medium. The porous medium may comprise coke or a coke-containing adsorbent. In a heat exchanger, which also houses the porous medium, cooling is performed using a heat exchange medium (see PCT/AU 2014/001135). Clean product gas is produced as stream 355.

The method and system 300 of the present invention also provides the option of reforming or combusting the heavier fraction 164 from the reactive distillation of the bio-crude. Stream 164 is passed through pressure regulating device/valve 165 to form stream 166 at a pressure level approaching the operating pressure required for reformer 360. Stream 166 is mixed with a mixture of reforming reagents 365 before entering reformer 360, at the inlet of reformer 360, or after inside reformer 360. Stream 365 may contain high concentrations of oxygen and other reforming agents, such as steam and CO ₂ . In particular embodiments, stream 365 is primarily air or oxygen, with heavier fraction 164 (166) being combusted therein. Reformate gas 367 exiting reformer 360 may enter reformer 320 or enter a hot gas cleaning system (340). Ash 366 is discharged.

An important advantage of reactive distillation is that the bio-crude 101 is separated into a lighter fraction 167 and a heavier fraction 164, which have very different reforming activities and can be reformed under very different conditions. In a particular embodiment, the heavier fraction 164 is simply combusted with a high concentration of oxygen in the reformer 360. The thermal energy embedded in the product gas 367 is used to meet the thermal requirements of the endothermic reaction in the reformer 320. Lighter and more reactive fraction 167 can therefore be reformed with less oxygen in reformer 320 and therefore with higher efficiency. Burning the heavier and more difficult to process fraction (164) represents the fastest and most efficient way to reform the bio-oil 101.

Another important advantage is that the lighter fraction 167 with reduced coking tendencies can be reformed catalyzed in the reformer 320 with longer catalyst life, while the heavier fraction with better propensity to form coke can be burned or reformed without catalyst.

In an embodiment, one or more reforming reactors operate as combustion reactors. In further embodiments, reformate from any or all reforming or combustion reactors is further subjected to cleaning using coke or coke-loaded catalysts, such as the two-stage hot clean gas cleaning process (340 and 350) mentioned above.

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising" will be 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, due to the express language or necessary implication.

It will be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art in australia or any other country.

Claims

1. A method of reactively distilling a biological crude oil, the method comprising:

providing a feed mixture of bio-crude formed by heat treating a carbonaceous feed comprising biomass;

heating the feed mixture at an elevated pressure, wherein the elevated pressure is above ambient pressure, and wherein evaporation of water and light materials is impeded; and

another fluid is mixed with the bio-crude and its reaction products such that the partial pressure of the substances initially present in the bio-crude and formed by the reaction of the bio-crude is reduced such that the substances distill to form different fractions.

2. The method of claim 1, wherein the feed mixture further comprises an additive capable of reacting with the bio-crude, catalyzing and/or inhibiting reactions involving the bio-crude and/or dissolving the bio-crude and/or reaction products thereof.

3. The process of claim 1, wherein the biocrude is heated at an elevated pressure generated by the vapor of the feed mixture itself.

4. The method of claim 1, wherein the bio-crude is heated at an elevated pressure created by a pressurized fluid surrounding the bio-crude.

5. The method of claim 1, wherein the bio-crude is heated at an elevated pressure created by a combination of a pressurized fluid and a confined space that delays volatilization of components from the bio-crude.

6. The method according to any of the preceding claims 1-5, wherein the total system pressure is reduced such that the partial pressure of all substances initially present in and/or originating from the bio-crude is reduced.

7. The method of claim 1, wherein the fluid reacts with the bio-crude.

8. The process of any one of claims 1-5, wherein the process further comprises hydrotreating one or more of the fractions formed by distillation with a hydrogenating reagent to produce a hydrotreated product.

9. The process of claim 8, wherein the hydrogenation reagent comprises one or more H-donating compounds capable of providing activated hydrogen in a hydrotreating reactor.

10. The process of claim 9, wherein the hydrogenation reagent comprises one or more compounds capable of generating free radicals to stabilize broken bonds in the hydrotreating reactor.

11. The process of claim 9, wherein the hydrogenation reagent comprises the hydrotreated product.

12. The method of claim 11, wherein the hydrogenation reagent comprises hydrogen.

13. The method of claim 12, wherein hydrogen is used as a pressurized fluid surrounding the bio-crude to produce an elevated pressure.

14. The method of claim 13, wherein the hydrogen is also mixed with the bio-crude and its reaction products such that the partial pressure of substances initially present in the bio-crude and formed by the reaction of the bio-crude is reduced such that the substances distill to form a fluid of different fractions.

15. The process of claim 8 wherein the fraction to be hydrotreated is rapidly heated to a hydrotreating reaction temperature in the presence of a hydrotreating catalyst.

16. The process of claim 8 wherein the lighter fraction and the heavier fraction are separated in a hydrotreating reactor that hydrotreats at least one separated fraction, wherein an initial stage of the hydrotreating reactor performs a separation function.

17. The method of claim 1, wherein the method further comprises reforming one or more of the fractions formed by distillation to produce a reformed product.

18. The method of claim 17, wherein the fraction is reformed with any one of steam, air, oxygen, carbon dioxide, hydrogen, or a mixture containing any two or more thereof.

19. The method of any one of claims 1 to 5, wherein the bio-crude is bio-oil from pyrolysis of a carbonaceous feed comprising biomass.

20. The method of any one of the preceding claims 1 to 5, wherein the biocrude is a product from the hydrothermal liquefaction of a carbonaceous feedstock comprising biomass.

21. A system for reactive distillation of a biological crude oil, the system comprising:

at least one inlet for feeding a feed mixture of biocrude formed by heat treating a carbonaceous feed comprising biomass into a distillation reactor capable of being pressurized;

a heat source and means for heating the biocrude in the distillation reactor at an elevated pressure to form a product mixture comprising reaction products and unreacted components, wherein the elevated pressure is above ambient pressure, and wherein evaporation of water and light materials is hindered; and

at least one outlet for allowing the product mixture to leave the distillation reactor to enter an evaporation vessel;

Wherein a further fluid is introduced which mixes with the product mixture and dilutes the product mixture to reduce the partial pressure of components in the product mixture so that the volatile species in the product mixture evaporate to form one or more condensed and vapor phases.

22. The system of claim 21, wherein the feed mixture further comprises an additive.

23. The system of claim 21 or 22, wherein the distillation reactor is a coil or a series of coils.

24. The system of claim 21 or 22, wherein the distillation reactor is immersed in a heating medium.

25. The system of claim 24, wherein the heating medium is a fluid in which the distillation reactor is immersed.

26. The system of claim 24, wherein the heating medium is a bath of fluidized sand in which the distillation reactor is immersed.

27. The system of claim 21 or 22, wherein the partial pressure of the components in the product mixture is reduced using a pressure let down valve or an orifice through which a product stream flows in a controllable manner.

28. The system of claim 21 or 22, wherein the additional fluid is a gas.

29. The system of claim 21 or 22, wherein the evaporation vessel is a coil or a series of coils.

30. The system of claim 21 or 22, wherein the distillation reactor and the vaporization vessel are the same vessel.

31. The system of claim 21 or 22, wherein the system further comprises means for cooling and condensing the volatile phase into more than one fraction.

32. The system of claim 22, wherein the additive is capable of reacting with the bio-crude, catalyzing and/or inhibiting reactions involving the bio-crude and/or dissolving the bio-crude and/or reaction products thereof.

33. The system of claim 21 or 22, wherein the system further comprises one or more reactors in which one or more heavier fractions are fed for heat treatment to produce additional lighter products.

34. The system of claim 21 or 22, wherein the bio-crude is bio-oil from pyrolysis of a carbonaceous feed comprising biomass.

35. The system of claim 21 or 22, wherein the bio-crude is a product from the hydrothermal liquefaction of a carbonaceous feed comprising biomass.