A method for providing pyrolysis oil from holocellulose and lignin containing biomass.
A two-stage pyrolysis process with controlled oxygen exclusion and extended treatment in a second reactor enhances the yield and energy content of pyrolysis oil from biomass by optimizing the thermal decomposition of holocellulose and lignin.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- BTG BIOLOQUIDS BV
- Filing Date
- 2022-10-31
- Publication Date
- 2026-04-13
AI Technical Summary
Existing fast pyrolysis technologies face challenges in optimizing yield, reducing water content, and increasing the energy content of pyrolysis oil, particularly in the production of pyrolysis oil from biomass.
A two-stage pyrolysis process involving a first reactor for rapid pyrolysis with a short residence time and a second reactor for extended pyrolysis treatment in the absence of oxygen, using a solid heat transfer medium to enhance thermal decomposition of holocellulose and lignin, with a controlled separation of solids to prevent oxygen ingress.
The method improves pyrolysis oil yield, reduces water content, and increases the carbon-to-oxygen ratio, resulting in higher-quality pyrolysis oil with enhanced energy content.
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Figure 2026511293000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a method for providing pyrolysis oil from holocellulose and lignin, including biomass. This method provides, inter alia, an improved pyrolysis oil / carbide ratio or a higher yield. This method further provides pyrolysis oil having, inter alia, an improved carbon (C) / oxygen (O) ratio or energy content.
Background Art
[0002] Fast pyrolysis, like slow pyrolysis, is the heating of biomass in the absence of oxygen. Unlike slow pyrolysis, fast pyrolysis generally uses a high heating rate, short residence time, and rapid cooling of the vapor to maximize the production of organic liquid oily products, also called bio-oil and pyrolysis oil.
[0003] [[ID=十六]]The fast pyrolysis of biomass with a high heating rate and rapid cooling of the vapor minimizes secondary decomposition reactions and repolymerization. Operation at high temperatures results in a relatively high yield of pyrolysis oil. The fast pyrolysis of biomass typically includes the steps of drying the biomass to less than 10 wt.% moisture and grinding the biomass into particles of 2 - 3 mm. Some techniques for fast pyrolysis include - A fast pyrolysis process using a fluidized bed reactor, developed, inter alia, by Dynamotive Energy Systems Corporation - RTP (Rapid Thermal Processing) using a transport dilution fluidized bed, developed by Ensyn Technologies; and - A fast pyrolysis process using a fluidized bed reactor, developed by Savon Voima; and - A fast pyrolysis process using a modified rotating cone reactor, developed by Biomass Technology Group which are commercially available.
[0004] In the first three technologies, the circulation of non-condensable products causes the bed to fluidize, and the rate of their fluidization determines the residence time of the vapors in the reactor. In all cases, a portion of the gas produced is used to provide energy for pyrolysis. In particular, in the RTP process, a heat-transporting, diluted fluidized bed, usually sand, circulates in two reactors: the first is dedicated to pyrolysis, and the second reheats the sand particles by burning the carbides formed during pyrolysis.
[0005] On the other hand, the process commercialized by BTG is based on the intensive mixing of biomass particles and hot sand in a modified rotating cone reactor. Because it does not use a carrier gas, the volume of steam discharged from the reactor is much lower than that of a fluidized bed reactor, and as a result, the size of the condenser for recovering the bio-oil is smaller than with other technologies. The solid flow containing char and sand particles is recycled to a combustion section, where the combustion of the char provides the energy to reheat the sand particles that are sent back to the pyrolysis reactor.
[0006] While fast pyrolysis technology is already commercially available, there is a continuing demand in the technical field to improve parameters of the fast pyrolysis process, such as optimizing yield, reducing water content, and / or increasing the energy content of the resulting pyrolysis oil. [Overview of the project] [Problems that the invention aims to solve]
[0007] The objective of this invention is to satisfy the needs of the above-mentioned technical field. [Means for solving the problem]
[0008] The above needs are met by the present invention as described in the attached claims.
[0009] Specifically, the above-mentioned demand according to the present invention is a method for providing pyrolysis oil from holocellulose and lignin, including biomass, a) A step of separately introducing biomass and a solid heat transfer medium having a temperature of 400°C to 700°C into a first reactor or first reaction zone; b) Providing a first-time pyrolysis treatment, which is a period of 0.5 to 5 seconds, in which biomass and a solid heat transfer medium are continuously mixed in a first reactor or first reaction zone in the absence of oxygen, yielding a mixture containing partially pyrolyzed biomass and solid heat transfer medium, as well as primary pyrolysis gas; b1) Optionally, a step of collecting primary pyrolysis gas from the first reactor or the first reaction zone; c) A step of introducing a mixture from a first reactor or first reaction zone to a second reactor or second reaction zone, wherein the second reactor or second reaction zone is configured to allow gravity to precipitate or separate a solid at the bottom of the second reactor or second reaction zone, thereby forming a layer of solid at the bottom of the second reactor or second reaction zone; d) A step of maintaining the mixture in the absence of oxygen in a second reactor or reaction zone for a second period of pyrolysis treatment, which is 10 to 1200 seconds, to further yield secondary pyrolysis gas and solid carbides, and collecting the pyrolysis gas from the second reactor or reaction zone; e) A step of condensing the collected primary and secondary pyrolysis gases into pyrolysis oil by rapidly cooling to a temperature of 60°C or lower, preferably; This is satisfied by a method that includes [a specific method].
[0010] The inventors of this application have surprisingly discovered that, compared to the prior art, extending the time of the pyrolysis treatment in the second reactor improves the yield of pyrolysis oil, reduces the water content of the resulting pyrolysis oil, and / or improves the energy content of the resulting pyrolysis oil, as indicated by a higher carbon (C) / oxygen (O) ratio.
[0011] While not intended to be limited to a specific mechanism, the inventors assume that holocellulose (hemicellulose and cellulose) present in biomass is primarily subjected to thermal decomposition (crushing) in the first reactor or reaction zone, while the increased time in the second reactor or reaction zone allows for additional thermal decomposition (crushing) of lignin in particular.
[0012] In the method according to the present invention, no further heat is introduced except for the heat provided by the heat transfer medium introduced into the first reactor or reaction zone.
[0013] According to the present invention, the method can be carried out in a single apparatus including separate reaction vessels or separate reaction zones that enable the necessary mixing and separation.
[0014] According to the present invention, a solid layer (generally containing sand and charcoal) at the bottom of the second reactor or reaction zone appears essential to prevent oxygen from entering the second reactor or reaction zone.
[0015] In a preferred embodiment of the present invention, the duration of the second time is determined by the height of the layer or dipleg of the solid precipitated or separated at the bottom of the second reactor or reaction zone. The solid is mainly a mixture of a heat transfer medium and (partially) pyrolytically treated biomass or char.
[0016] In a particularly preferred embodiment of the present invention, the duration of the second time is controlled by the height of the layer of precipitated or separated solid at the bottom of the second reactor or reaction zone, where an increased height increases the duration of the second time. In the second reactor or reaction zone, the height of the solid layer at the bottom can be easily controlled using a level controller that removes solid from the bottom of the second reactor or reaction zone.
[0017] In a preferred embodiment of the present invention, the second time of the method is 10 to 900 seconds, preferably 50 to 900 seconds, more preferably 100 to 900 seconds, and most preferably 200 to 720 seconds.
[0018] In the present invention, the solid heat medium is selected from the group consisting of silicate minerals, catalytic minerals, metals, zeolites, and sand. Sand is preferred because it is readily available and an inert material.
[0019] The present method provides a pyrolysis oil having an increased C content, a pyrolysis oil having an increased oil / carbide ratio or yield, and / or a pyrolysis oil having an increased C / O ratio or energy content.
[0020] Suitable holocellulose and lignin having biomass used in the present method can be selected from the group consisting of wood, wood products, agricultural products, agricultural waste, horticultural products, horticultural waste, forest products, forest waste, human and animal waste; food processing industries, wood chips, sawdust, wood pellets, bark, seeds, kernels, husks, and combinations thereof.
[0021] In the present invention, the first time is determined by the volume of the first reactor or reaction zone and the supply rates of the biomass and the solid heat medium. That is, the first reactor or reaction zone is configured and operated to provide a residence time of 0.5 to 5 seconds.
[0022] The present method is preferably a continuous process. That is, the biomass and the solid heat medium are continuously supplied to the first reactor or reaction zone, the pyrolysis gas is continuously collected from the reactor or reaction zone, and the solid heat medium and the carbide are continuously removed from the second reactor or reaction zone.
[0023] Preferably, the water content of the biomass is less than 10 wt.%, preferably less than 5 wt.% and more preferably less than 3 wt.% or less than 4 wt.%.
[0024] In the present invention, the temperature of the heat medium during step (a) is preferably 450 to 650 °C, more preferably 450 to 600 °C.
[0025] In a preferred embodiment of the present invention, the first reactor or the first reaction zone includes mixing means, an inlet for biomass and a heat medium, an outlet for a mixture containing partially pyrolyzed biomass and a solid heat medium, and optionally an outlet for primary pyrolysis gas.
[0026] In a preferred embodiment of the present invention, the second reactor or the second reaction zone includes means for separating solid particles and gas by gravity, an inlet for a mixture containing partially pyrolyzed biomass and a solid heat medium into the second reactor, an outlet for solids precipitated or separated at the bottom of the second reactor, and an outlet for pyrolysis gas.
[0027] The present invention will be further described in the following examples. In the examples, reference is made to the drawings.
Brief Description of the Drawings
[0028] [Figure 1] FIG. 1 shows a schematic diagram of the method. The upper part of FIG. 1 shows an embodiment in which pyrolysis gas is collected from the first and second reactors. The lower part of FIG. 1 shows an embodiment in which gas is collected from the second reactor. [Figure 2] FIG. 2 shows a schematic diagram of the second reactor with various heights of layers or inclined legs (gray regions) of solids precipitated or separated at the bottom of the second reactor. [Figure 3] FIG. 3 graphically shows the relationship between the yield, carbon content, and energy content of pyrolysis oil and the residence time in the second reactor or reaction zone. [Figure 4] FIG. 4 graphically shows the relationship between carbonized products and the residence time in the second reactor or reaction zone.
Modes for Carrying Out the Invention
[0029] Introduction In this invention, the pyrolysis of biomass can be distinguished into two stages: 1) crushing of holocellulose (hemicellulose and cellulose), and 2) crushing of lignin. Both stages yield different products and preferably require two crushing methods. The first crushing method generally involves rapidly increasing the temperature to crush the holocellulose, and then rapidly cooling the resulting pyrolysis gas (primary gas) to prevent its subsequent permanent conversion into gas and water. The second crushing method generally involves exposing the lignin to a high temperature, however, unlike the crushing of holocellulose, the lignin is kept at a high temperature to obtain sufficient conversion. The resulting gas is then guided to a hot sand bed and further crushed to obtain short-chain carbon products (secondary pyrolysis gas).
[0030] The present invention relates to a method in which both pyrolysis steps are preferably combined into a single pyrolysis process. 1) High-quality oils (less water, more organic components, more acid-emulsifiers, smaller phenol chains, lower polarity, and lower tendency towards phase separation); 2) Less fragmented "non-condensable gas" from the primary gas yields a higher oil yield. 3) The increased lignin is broken down, resulting in less "carbon" and thus a higher oil yield. This provides a competitive advantage.
[0031] An embodiment of this method is schematically shown in Figure 1. This method uses two reactors, in which biomass and a heat transfer medium are supplied to a first reactor configured to provide a residence time of 0.5 to 5 seconds. The partially pyrolyzed biomass is then supplied to a second reactor configured to provide a residence time of 10 to 1200 seconds.
[0032] Specifically, biomass and heat transfer medium (sand) are supplied to reactor 1 and immediately physically mixed. In reactor 1, "rapid pyrolysis" takes place, characterized by rapid heating of the biomass and a short residence time of the primary gas. The residence time of the primary gas is kept as short as possible (on the scale of 0.5 to 5 seconds).
[0033] Due to rapid pyrolysis, the mixture of biomass, heat transfer medium (sand), and crushed gas leaves reactor 1 and moves towards reactor 2 (separator). The primary pyrolysis gas from rapid pyrolysis rises directly into the separator, while the heat transfer medium (sand) and solid biomass (which is incompletely crushed due to the short residence time in the first reactor) descend into the separator (by gravity).
[0034] The solid forms a layer (inclined leg) that slowly sinks into the separator (with a residence time of approximately 10 to 900 seconds). Due to the high temperature within the inclined leg (generally above 350°C), the lignin "cracks through," and the remaining material moves upward through the hot sand bed, eventually producing gas that forms secondary pyrolysis gas.
[0035] The combination of primary and secondary gases is condensed into a liquid (pyrolysis oil) via, for example, a cyclone, while the heat transfer medium (sand) and the completely converted biomass (carbonized material) leave the separator via the bottom. [Examples]
[0036] Experimental apparatus Using a small pilot plant with inclined legs of three different sand height levels (as schematically shown in Figure 2), pyrolysis was carried out to demonstrate the effect of lignin residence time in the inclined legs on the quality and yield of the resulting pyrolysis oil.
[0037] Specifically, three experiments were conducted using woody biomass, clean sand, and starting fluid, varying the screw output for sand and char removal in the separator (reactor 2) experimentally. The experiments were conducted to provide different height levels (I, II, and III) of the inclined legs for each operation, while keeping other operating parameters constant. The different height levels used were I = very low; II = low level; III = high level, immediately before oxygen transport. In the experimental apparatus used, the residence times obtained in reactor 2 were III: 11 minutes (operation 1); II: 4.5 minutes (operation 2); I: 3.6 minutes (operation 3).
[0038] result As shown in Figure 3 and the table below, 1) The increased C / O ratio indicates a higher amount of organic components. 2) Lower water content in pyrolysis oil This resulted in higher quality pyrolysis oil at a higher separator level.
[0039] As shown in Figure 4 and the table below, a higher oil / carbide ratio (mass balance) was obtained.
[0040] [Table 1]
[0041] [Table 2]
[0042] [Table 3]
[0043] [Table 4]
[0044] [Table 5]
Claims
1. A method for providing pyrolysis oil from holocellulose and lignin containing biomass, a) A step of separately introducing the biomass and a solid heat transfer medium having a temperature of 400°C to 700°C into a first reactor or a first reaction zone; b) Providing a first-time pyrolysis treatment, which is a period of 0.5 to 5 seconds, in which the biomass and solid heat transfer medium in the first reactor or the first reaction zone are continuously mixed in the absence of oxygen, yielding a mixture containing partially pyrolyzed biomass and solid heat transfer medium and primary pyrolysis gas; b1) Optionally, a step of collecting primary pyrolysis gas from the first reactor or the first reaction zone; c) A step of introducing the mixture from the first reactor or first reaction zone to a second reactor or second reaction zone, wherein the second reactor or second reaction zone is configured to provide a precipitate or separation of solids at the bottom of the second reactor or second reaction zone by gravity, thereby forming a layer of solids at the bottom of the second reactor or second reaction zone; d) Maintaining the mixture in the second reactor or reaction zone in the absence of oxygen for a second period of pyrolysis treatment, which is 10 to 1200 seconds, to further yield secondary pyrolysis gas and solid carbides, and collecting the pyrolysis gas from the second reactor or reaction zone; e) A step of condensing the collected primary pyrolysis gas and secondary pyrolysis gas into pyrolysis oil by rapidly cooling to a temperature of 60°C or lower, preferably; Methods that include...
2. The method according to claim 1, wherein the second time in the pyrolysis treatment is determined by the height of the layer of solid precipitated or separated at the bottom of the second reactor or second reaction zone.
3. The method according to claim 2, wherein the second time is controlled by the height of the layer of solid precipitated or separated at the bottom of the second reactor or second reaction zone, and an increased height increases the second time.
4. The method according to any one of claims 1 to 3, wherein the second time in the thermal decomposition treatment is 10 to 900 seconds, preferably 50 to 900 seconds, more preferably 100 to 900 seconds, and most preferably 200 to 720 seconds.
5. The method according to any one of claims 1 to 4, wherein the solid heat transfer medium is selected from the group consisting of silicate minerals, catalyst minerals, metals, zeolites, and sand.
6. The method according to any one of claims 1 to 5, which provides a pyrolysis oil having an increased carbon content.
7. The method according to any one of claims 1 to 6, which provides a pyrolysis oil having an increased oil / carbide ratio or yield.
8. The method according to any one of claims 1 to 7, which provides a pyrolysis oil having an increased C / O ratio or energy content.
9. The method according to any one of claims 1 to 8, wherein the biomass-containing holocellulose and lignin are selected from the group consisting of wood, wood products, agricultural products, agricultural waste, horticultural products, horticultural waste, forest products, forest waste, human and animal waste; food processing industry, wood chips, sawdust, wood pellets, bark, seeds, kernels, husks, and combinations thereof.
10. The method according to any one of claims 1 to 9, wherein the first time is determined by the volume of the first reactor and the supply rate of biomass and solid heat transfer medium.
11. The method according to any one of claims 1 to 10, which is a continuous process.
12. The method according to any one of claims 1 to 11, wherein the water content of the biomass is less than 10 wt.%, preferably less than 5 wt.%, more preferably less than 3 wt.%, or 4 wt.%.
13. The method according to any one of claims 1 to 12, wherein the temperature of the heat transfer medium in step (a) is 450 to 650°C, preferably 450 to 600°C.
14. The method according to any one of claims 1 to 13, wherein the first reactor or first reaction zone includes a mixing means and an inlet for the biomass and the heat transfer medium, an outlet for a mixture containing partially pyrolyzed biomass and a solid heat transfer medium, and optionally an outlet for primary pyrolysis gas.
15. The method according to any one of claims 1 to 14, wherein the second reactor or second reaction zone includes means for separating solid particles and gases by gravity, and the second reactor further includes an inlet for the mixture comprising partially pyrolyzed biomass and a solid heat transfer medium, an outlet for solids settled or separated at the bottom of the second reactor, and an outlet for pyrolysis gases.