Method and device for industrial production of renewable synthetic fuel

Abstract

A process and apparatus for converting biomass and / or carbonaceous solid waste material to syngas is provided. The method includes providing a densified and pressurized feedstock to a gasifier, and the gasifier including a fluidized bed zone and a post-gasification zone, and contacting the feedstock with a gasifying agent. The synthesis gas is then recovered and purified, involving the recovery of CO2 to various stages of the process. The apparatus is configured to perform the method and includes a delivery conduit for recovering CO2. The syngas may be further processed into renewable synthetic products and / or chemicals.

Description

Technical Field

[0001] The present invention relates to a low carbon footprint process and apparatus for converting biomass and / or carbonaceous solid waste materials into more useful syngas products. By using a gasification apparatus having a fluidized bed and a post-gasification zone, the conversion of the feedstock is achieved, and an economical and environmentally friendly downstream treatment can be used to purify the syngas product into a pure syngas that can be used to produce a variety of renewable synthetic products and / or chemicals. Background Art

[0002] Waste materials, such as municipal solid waste (MSW), agricultural and industrial wastes, etc., are mainly disposed of by landfilling and / or incineration. Currently, waste recycling is receiving increasing attention because it allows most of the used materials (such as paper, some plastics, glass, metals, etc.) to be reused. However, other non-recyclable materials are still either dumped into landfills or incinerated to convert the chemical energy therein into electricity and heat. However, this energy cannot be stored.

[0003] Therefore, there is a need for a method and apparatus that can better handle these other non-recyclable materials.

[0004] The gasification of biomass and non-recyclable carbonaceous solid waste materials converts the waste into syngas, thus providing the possibility of converting the waste into more valuable products (such as synthetic products and / or chemicals). In other words, the gasification of waste helps to recycle waste materials in a different way from traditional recycling methods by converting the carbon in the waste into more useful molecules (i.e., syngas), and then synthesizing it into valuable final products. Generally speaking, the gasification of biomass and waste materials can bring the following advantages to the community: (1) Utilize carbonaceous solid waste materials in an environmentally friendly manner without emitting toxic substances into the atmosphere; (2) Provide the most efficient way to convert the chemical energy stored in waste such as municipal solid waste (MSW) into electricity; (3) Provide the most efficient way to convert the carbon content in municipal solid waste (MSW) or refuse-derived fuel (RDF) into high-value products (such as chemicals or synthetic fuels).

[0005] Synthesis gas is generally a fuel gas mixture mainly composed of hydrogen, carbon monoxide and often also some carbon dioxide. It is often used as an intermediate for synthetic natural gas and the production of ammonia or methanol. Synthesis gas (syngas) can be produced by the thermochemical conversion of carbonaceous feedstock materials such as forest residues, agricultural residues, industrial and municipal wastes, etc. Generally speaking, the gasification of such carbonaceous feedstock materials produces raw syngas, which may contain several impurities such as sulfides (mainly hydrogen sulfide H2S and carbonyl sulfide COS), ammonia, chlorides (mainly hydrogen chloride HCl), volatiles, low (methane CH4, ethane C2H6, etc.) and high (tar) molecular weight hydrocarbons, as well as fine particulate matter (mainly in the form of micron and sub-micron fly ash, containing metal salts), and granular carbon (usually above 500 microns). It is expected that biomass and other carbonaceous solid waste materials can be converted into syngas through efficient processes and equipment, and then the syngas can be used to produce high-value materials and synthetic products / fuels such as methanol, hydrogen, ammonia, synthetic natural gas and / or Fischer-Tropsch synthetic fuels.

[0006] Various methods have been proposed for the production, purification and modification of raw syngas from carbonaceous materials. These existing methods are briefly discussed below.

[0007] U.S. Patent No. 6,063,355 discloses a method for treating waste through two consecutive fluidized bed and combustion reactors. The solidified and / or slurry waste is introduced into a fluidized bed with a rotating flow pattern at a temperature range from 450°C to 650°C to produce gaseous and carbonaceous materials. These products directly enter a rotating flow combustion reactor separated from the fluidized bed reactor, and the temperature is raised to at least 1300°C to produce syngas. Then the raw syngas produced in the second reactor is cooled to separate slag, and the cooled raw syngas is further cleaned through a cyclone separator and a scrubber. This method involves the use of two consecutive fluidized beds, resulting in higher capital and operating costs, as well as other inefficiencies.

[0008] DE 4317319 A1 discloses a gasification-based technology for producing raw syngas, which is adjusted and used as a feedstock for alternative end products such as methanol, clean syngas, and hydrogen. The shredded waste is fed into two parallel-connected fixed-bed gasifiers, where the waste reacts with oxygen, steam, and raw carbon dioxide at a maximum temperature of 1200 °C. The resulting raw syngas is partially fed into a suspension fluidized-bed gasifier at a temperature of 1400 °C and a pressure of 26 bar (2600 kPa), and the other part enters a process chain consisting of a washing, heat recovery, and cooling stage, followed by a two-stage gas scrubber, COS hydrolysis reaction, and finally used for power generation. The raw syngas produced from the suspension fluidized-bed gasifier is further processed through a soot scrubber, followed by CO conversion, gas cooling, and washing, and finally used for methanol production. Also, the use of two parallel fixed-bed gasifiers and a suspension fluidized-bed gasifier results in higher capital and operating costs, as well as many other inefficiencies.

[0009] EP 2376607 B1 and EP 2274404 B1 disclose a method for producing and treating raw syngas from biomass at a pressure below 10 atmospheres (1013 kPa) through a three-step gasification and reforming process. The solid biomass is fed into the bottom part of a fluidized-bed reactor, i.e., the so-called gasification zone, in the presence of oxygen and steam, with a temperature range between 500 °C and 750 °C (first step). A part of the oxidized biomass produced in the first step is directly treated in a free combustion zone with a residence time below 8 seconds, in the presence of oxygen and steam, with a temperature range from 800 °C to 850 °C (second step). The part of the oxidized biomass produced in the second step is then treated with an oxidizing gas containing oxygen and steam in a separate thermal reformer at a temperature of at least 900 °C and not exceeding a maximum temperature of 1000 °C to produce raw syngas (third step). The raw syngas produced in the thermal reformer is then further cleaned through a cyclone separator, a heat recovery device, and a final scrubber. This method has some disadvantages, such as:

[0010] - The third step occurs in a separate thermal reformer unit, which means additional reactors are required, resulting in higher capital and operating costs;

[0011] - The method is limited by the operating pressure of the gasifier, which is below 10 atmospheres (1013 kPa). This leads to a larger gasifier unit size when processing a larger quantity of feedstock.

[0012] - Due to the short residence time in the post-gasification zone, heavier hydrocarbons cannot be completely decomposed, so a subsequent separate thermal reforming unit (as described above) is required. And

[0013] - Gasification relying on external catalysts and bed materials increases the operating costs of the system and also has some other inefficiencies.

[0014] All existing technical methods have some different disadvantages, so there is still a need for processes and equipment to convert raw materials containing biomass and / or carbonaceous solid waste into syngas in a more efficient, environmentally friendly and economical way.

[0015] In the prior art, various different methods have been tried to convert biomass and / or waste into more useful products, such as syngas, but all existing methods have the significant disadvantages as described above. Currently, the main methods for preparing syngas from biomass include (1) decentralized biomass pyrolysis followed by production of pyrolysis oil, (2) production of pyrolyzed biomass after decentralized pyrolysis, and (3) biomass / waste gasification. The inventors of the present invention have now found that the principle of the high-temperature Winkler (HTW) technology can be improved to provide an environmentally friendly and improved process and equipment for most effectively converting carbon in biomass and / or carbonaceous solid waste into syngas. HTW gasification is a method that has been used for a long time and is usually carried out under high pressure, and can be described as a fluidized bed gasification process with pressure loading. The HTW method was initially used for a wide range of applications, but until now, there has been a difficulty in developing the existing HTW technology to effectively convert biomass and / or carbonaceous solid waste into syngas. The present invention provides an efficient and environmentally friendly process and equipment for converting biomass and / or carbonaceous solid waste into syngas and subsequently producing high-value products, such as chemicals.

[0016] U.S. Patent Application 2018 / 0291278 A1 discloses a bioreforming reactor formed by a multi-stage reactor for producing chemical-grade biosyngas for any one of the following uses: 1) a methanol synthesis reactor, 2) a reactor group for converting methanol to gasoline, 3) a reactor group for high-temperature Fischer-Tropsch, and 4) any combination of the above three using chemical-grade biosyngas obtained from biomass input into the bioreforming reactor.

[0017] N. Hanchate, S. Ramani, C. S. Mathpati and V. H. Dalvi reported the biomass gasification using a dual-fluidized bed gasification system in the Journal of Cleaner Production, 2021, Volume 280 (pages 123 - 148).

[0018] International Patent Application WO 2011 / 018192 A4 discloses a method for supplying a carbonaceous fuel to a entrained-flow gasification reactor. Summary of the Invention

[0019] In a first aspect of the present invention, there is provided a process for converting biomass and / or carbonaceous solid waste materials into syngas, the process comprising the following steps:

[0020] (a) Concentrating the feedstock;

[0021] (b) Pressurizing the concentrated feedstock in a pressurizing device;

[0022] (c) Supplying the feedstock from step (b) to a gasifier, optionally using a high-temperature Winkler (HTW) gasifier, the gasifier comprising a fluidized bed zone and a post-gasification zone;

[0023] (d) Converting the feedstock into a syngas product by contacting the feedstock with a gasifying agent in the gasifier; and

[0024] (e) Recovering syngas from the product produced in step (d), wherein recovering syngas comprises separating at least a portion of CO2 from the product produced in step (d) and recycling at least a portion of the separated CO2 back to the pressurizing device and recycling at least another portion of the separated CO2 back to the gasifier, thereby improving the efficiency of the overall gasification process.

[0025] According to the present invention, the process provides a simple, relatively low-cost and efficient method for converting feedstocks containing biomass and / or carbonaceous solid waste into syngas. Compared with prior art methods that rely on the use of multiple units (e.g., reactors and supplementary reformers / burners), the use of a single gasifier that includes both a fluidized bed zone and a post-gasification zone greatly simplifies the process.

[0026] It has been found that densifying and pressurizing the feedstock before it enters the gasifier enables the gasifier to operate at high pressure and provides a feedstock with a higher carbon density than fragmented or non-pelletized materials. The densified feedstock can be in the form of pellets. Optionally, these pellets can be cylindrical, with a diameter generally ranging from about 4 mm to 30 mm, particularly from about 4 mm to about 15 mm, more specifically, having dimensions of about 6 mm, 8 mm or 12 mm; and a length generally ranging from about 8 mm to about 80 mm. Operating the gasifier at high pressure is beneficial because it can produce syngas products at high pressure. This is useful because converting syngas into synthetic products also requires high pressure. Compared with systems operating at low pressure, the present invention has a significant energy-saving effect. This is because the pressure required to densify and pressurize the feedstock is much less than the pressure required to compress the syngas produced at a lower gasifier pressure to be converted into synthetic products. Therefore, the net energy consumption is lower than that of prior art systems that do not use densified and pressurized feedstock, making the present invention more environmentally friendly.

[0027] In addition, this gasification technology can convert biomass and / or solid carbon-containing waste into synthetic fuels and / or chemicals, enabling economically beneficial production on an industrial scale due to "economies of scale". A certain scale is required for the production of such synthetic products. For example, the capacity of such a plant should be greater than 100 MWth.

[0028] When recovering syngas from the product, i.e., purifying the syngas product to obtain pure or purer syngas, it has been found that a recycle line can be used to send CO2 back to the pressurization device and the gasifier. CO2 can act as a pressurizing agent in the pressurization device and as a gasifying agent in the gasifier. Therefore, the present invention not only recovers CO2 in the system but also actually re-uses it during the conversion of the feedstock into the syngas product and the pressurization of the feedstock through these transfer lines. Thus, the recovered CO2 is not merely reused as an inert gas but is recycled as a process gas and is at least partially converted into syngas (CO) through the Boudouard reaction in the gasifier. This makes the present invention more environmentally friendly than existing systems and has a lower carbon footprint.

[0029] In one embodiment, step (d) includes contacting the feedstock with a gasifying agent in a fluidized bed zone, where the gasifying agent can include steam, oxygen, and CO2, and its average temperature is about 250 - 500 degrees Celsius lower than the slag softening temperature of the feedstock to partially oxidize the feedstock.

[0030] In one embodiment, step (d) includes contacting the partially oxidized feedstock with a gasifying agent in a post-gasification zone, where the gasifying agent can include steam, oxygen, and CO2, and its average temperature is about 150 - 300 degrees Celsius lower than the slag softening temperature of the feedstock.

[0031] It has been found that these temperature ranges can effectively convert the feedstock into syngas and also allow the gasifier to have flexibility in other operating conditions such as pressure. In particular, this process allows the use of higher pressures, up to about 3000 kPa or about 4000 kPa, which enables the use of smaller-sized and more compact devices to obtain higher production capacities. Additionally, as mentioned above, higher gasification pressures are very beneficial for downstream processes. For example, processes such as synthesizing methanol, synthetic natural gas, or ammonia from the produced syngas all require high pressure. Therefore, less energy is required to operate the downstream processes since the raw syngas produced by the gasifier has a higher pressure.

[0032] In one embodiment, the process further includes setting the operating pressure of the fluidized bed and the post-gasification zone between about 200 kPa and about 3000 kPa or about 4000 kPa, optionally between about 1000 kPa and about 3000 kPa or up to about 4000 kPa, and optionally the gasifier is a refractory-lined reactor. The advantages of increasing the operating pressure have been explained herein.

[0033] In one embodiment, the densification of the feedstock in step (a) occurs in a densification device. Optionally, the densification includes granulating the feedstock in a granulation device. In this gasification process, it has been found that granulation is a particularly advantageous form of densification. In this regard, it has been found that difficulties may be encountered in directly introducing the feedstock into the high-pressure system after crushing and drying the feedstock. This is because the feedstock is prone to forming bridges and / or holes in the feed bin during gravity feeding. In addition, in the case of using light and fluffy materials, due to their low density, a large amount of pressurizing agent is required. It has been found that granulation is a very effective method to avoid the above problems in introducing the feedstock into a gasifier operating at such high pressures in an economical and efficient manner.

[0034] In one embodiment, the recovery of syngas further includes:

[0035] (e1) Filtering and cleaning the product produced in step (d);

[0036] (e2) Quenching, saturating, washing, and conditioning the product of step (e1); and

[0037] (e3) Treating the product of step (e2) to adjust the proportions of the components in the product.

[0038] In one embodiment, the temperature of the product entering the quenching and saturating step is at least 150 °C but does not exceed 400 °C. It has been found that introducing the syngas product into the quenching and saturating device within this temperature range can particularly effectively quench and saturate the product.

[0039] In one embodiment, the quenching and saturation include contacting the product with alkaline water having a pH value between approximately 8 and 11. It has been found that treating the product with alkaline water within this pH range can particularly effectively quench and saturate the product.

[0040] In one embodiment, the product leaving step (e2) has a zero chlorine content and a temperature not exceeding approximately 250 °C.

[0041] In one embodiment, the recovery of syngas further includes filtering dust in the product in a dry dust removal device.

[0042] In one embodiment, the process further includes recycling at least part of the filtered dust to step (a) (i.e., to the densification device), and / or recycling at least part of the filtered dry dust to step (b) (i.e., to the pressurization device). These recycling lines contribute to a significant increase in the overall conversion efficiency of the system because the returned dust (fly ash) contains a high carbon content that has not yet participated in the gasification reaction.

[0043] In a second aspect, there is provided a process for converting biomass and / or carbonaceous solid waste into synthetic products and / or chemicals, the process comprising:

[0044] According to the process of the first aspect, a feedstock containing biomass and / or carbonaceous solid waste material is converted into syngas; and

[0045] The syngas is converted into synthetic products and / or chemicals.

[0046] In one embodiment, the process further includes recycling the off-gas generated during the conversion of syngas into synthetic products and / or chemicals by converting the off-gas into syngas and returning the syngas to the step of converting syngas into synthetic products and / or chemicals. The total amount of syngas entering the system for converting syngas into synthetic products (such as methanol synthesis or Fischer-Tropsch synthesis) will increase, which will lead to an increase in the yield of the final product, thereby improving the economic efficiency of the process.

[0047] In a third aspect, there is provided an apparatus for converting a feedstock containing biomass and / or carbonaceous solid waste material into syngas, the apparatus comprising:

[0048] A feeding system including a densification unit and a pressurization unit;

[0049] A gasifier, optionally an HTW gasifier, including a fluidized bed zone and a post-gasification zone for thermally converting the feedstock into a syngas product, wherein the feeding system is configured to convey the feedstock to the gasifier; and

[0050] A processing system located downstream of the gasifier, configured to recover syngas from the syngas product, wherein the recovery system includes at least one CO2 separation unit configured to separate CO2 from the synthetic product;

[0051] Wherein, the processing system further includes a reflux pipeline between at least one CO2 separation unit and the pressurization unit, and a second reflux pipeline between at least one CO2 separation unit and the gasifier, and the reflux pipeline is configured to recycle at least a part of the separated CO2 into the pressurization unit and the gasifier, optionally,

[0052] The fluidized bed and the post-gasification zone are configured to operate at a pressure between about 200 kPa and about 3000 kPa or between about 200 kPa and about 4000 kPa, more optionally at a pressure between about 1000 kPa and about 3000 kPa or between about 200 kPa and about 4000 kPa.

[0053] In one embodiment, the processing system further includes a dry dust removal unit configured to filter dust from the product, and a reflux pipeline is provided between the dry dust removal unit and the densification unit and / or the pressurization unit, and the reflux pipeline is configured to recycle at least a part of the filtered dust to the densification unit and / or the pressurization unit.

[0054] The device provides the same advantages as the corresponding processing features, and these advantages have been described in the relevant processing procedure features.

[0055] The device may include any relevant device features discussed herein, and these features may be required to perform any processing features discussed in the first and second aspects of the present invention.

[0056] Certain embodiments of the present invention are shown in the drawings and described in detail below. Description of the Drawings

[0057] Figure 1 Shows an example processing and device arrangement for converting a raw material containing biomass and / or carbonaceous solid waste materials into syngas according to an embodiment of the present invention.

[0058] Figure 2 Shows a cross-section of two lock hoppers for pressurizing solid raw materials. If the raw material is not granulated, the raw material may form a bridge (left figure) or a hole (right figure). Detailed Description of the Embodiments

[0059] A method and a device with a low carbon footprint in the process of converting a raw material containing biomass and / or carbonaceous solid waste materials into syngas are provided herein to solve the problems existing in the prior art. These methods and devices comply with the claims of the present invention.

[0060] In this article, "high-temperature Winkler" gasification or "HTW" gasification can be described as a pressurized bubbling fluidized bed gasification process. The reactor used for HTW gasification is called an "HTW" gasifier. The HTW gasifier is a refractory-lined reactor, which generally includes a fluidized bed zone and a post-gasification zone, such as a free board zone, and a cyclone separator and a circulation line are equipped in the reactor. The HTW gasifier generally operates under the pressurization conditions disclosed herein, such as a pressure of about 200 kPa to about 3000 kPa or 200 kPa to about 4000 kPa, and the temperature disclosed in the present invention. The HTW gasifier is well known in the art, for example, it is described in the book "Coal and Biomass Gasification - Recent Advances and Further Challenges" by S. De et al., published by Springer Nature Singapore Pte Ltd in 2018.

[0061] In this document, the term "freeboard region" can be understood as the space between the upper surface of the fluidized bed and the gas outlet at the top of the gasifier during HTW operation.

[0062] In this document, the term "downstream" refers to the natural flow of the feedstock / synthesis gas in the process / plant, indicating a subsequent position or further along in the process / plant, and thus has its ordinary meaning in the art.

[0063] In this document, the term "syngas product" refers to the syngas produced by gasification before downstream processing, which includes syngas and undesirable impurities, i.e., raw syngas, unless otherwise expressly stated.

[0064] In this document, the term "syngas" refers to the syngas before downstream processing, which includes syngas and a lesser amount of undesirable impurities, i.e., pure or relatively pure syngas, unless otherwise expressly stated. In certain embodiments, "syngas" refers to a syngas product that has been treated to remove at least 25 wt% of the impurities, optionally at least 50 wt% of the impurities, optionally at least 75 wt% of the impurities, optionally at least 90 wt% of the impurities, optionally at least 95 wt% of the impurities, optionally at least 99 wt% of the impurities, based on the total weight of the impurities in the syngas product before downstream processing.

[0065] In this document, the term "synthesis product" refers to, unless otherwise expressly stated, synthetic fuels, chemicals, or other desirable products obtainable by the conversion of syngas, and thus has its normal meaning in the art. An example of a method for converting syngas into a synthesis product is Fischer-Tropsch conversion. An example of a synthesis product is bio-methanol. A synthesis product can include a single main synthesis product or multiple synthesis products. The term "synthetic chemical" refers to, unless otherwise expressly stated, a chemically synthesized product.

[0066] In this document, the term "reflux line" refers to, unless otherwise expressly stated, a transfer line in a system for transporting material upstream, i.e., back to an earlier unit in the system. Similarly, the term "recycle" as used herein (in connection with the return of material in a system and process) refers to, unless otherwise expressly stated, the transport / return of material to an upstream location in the process, i.e., an earlier step in the process. Typically, the recycled material can be used again in the system / process described herein.

[0067] The material transportation between units / steps in the equipment / process referred to in this article does not exclude the existence of intermediate units / steps, unless otherwise implied, technically infeasible or clearly stated, such as by using the word "direct". For example, if there is a reflux pipeline between two units, this does not exclude the possibility of intermediate units existing on the reflux pipeline, unless it is technically infeasible or otherwise implied / clearly stated.

[0068] As used herein, the term "a part" means, unless otherwise clearly stated, at least 1% by weight, optionally at least 10% by weight, optionally at least 20% by weight, optionally at least 30% by weight, optionally at least 40% by weight, optionally at least 50% by weight, optionally at least 60% by weight, optionally at least 70% by weight, optionally at least 80% by weight, optionally at least 90% by weight, optionally at least 95% by weight, optionally at least 99% by weight.

[0069] An embodiment of the process and apparatus of the present invention is as Figure 1 shown. The figure shows a general schematic diagram of this embodiment, in which the raw material is gasified to produce raw syngas with a low carbon footprint, and further undergoes a series of process steps, including cleaning, conditioning and modification, through a fly ash / carbon removal, quenching, washing, conditioning and compression unit. Thereafter, the tar-free and low-carbon footprint syngas becomes a suitable raw material for renewable synthetic fuel production.

[0070] In Figure 1 , biomass and / or carbonaceous waste (raw material) is introduced through a pipeline (1) by a shredder 101, which fragments the raw material into smaller particles. After shredding, the fragmented raw material is conveyed through a pipeline (2) to a drying device 102 for drying. In the drying device 102, the moisture content in the raw material is evaporated by natural drying (without additional heating) or artificial drying (using forced flue gas, steam or air). The shredded and dried carbonaceous material is then conveyed through a pipeline (3) by a granulator 103, where the raw material is compressed into pellets. At this stage, a small amount of additives can be premixed, including but not limited to magnesium compounds and some basic adsorbent materials, to neutralize impurities such as chlorine, fluorine, sulfur and alkali metals inherent in the pelletized carbonaceous raw material. Generally, these additives can be premixed with the raw material, with a specific gravity of approximately 3-5%.

[0071] The granulated feedstock is transported through a pipeline (4), and then enters a feeding system including a series of lock hoppers 104 and a star feeder (not shown) through pipelines (4a) and (4b), and then enters a feeding screw conveyor 105 through pipelines (5a) and (5b), and is introduced into a gasifier 106 through a feeding screw via a pipeline (6). The temperature of the feedstock when it enters the gasifier 106 is between 60 and 80 degrees Celsius. The feedstock is introduced into a fluidized bed zone ("zone" or "reaction chamber") 107 of the gasifier 106.

[0072] The granulated feedstock contacts a gasifying agent (including oxygen, steam, and / or carbon dioxide) in the fluidized bed zone 107 of the gasifier 106. The gasifying agent is introduced into the fluidized bed zone 107 of the gasifier 106 through pipelines (7) and (7a) at a controlled flow rate through a single-layer or dedicated multi-layer nozzle ( Figure 1 not shown) to provide an appropriate amount of the gasifying agent for the partial oxidation and thermochemical decomposition of the granulated carbonaceous feedstock to produce high-quality syngas. Although it is shown in Figure 1 that the gasifying agent is introduced into the gasifier 106 through the fluidized bed zone 107, in fact, the gasifying agent will be introduced at different positions in the gasifier 106.

[0073] The form and quantity of the gasifying agent introduced into the gasifier 106 depend on the nature of the feedstock to be gasified. Generally, the gasifying agent is supplied to the gasifier 106 such that the oxygen content in the gasifier 106 is within a controlled range of 0.28 - 0.52 Nm3 / kg (daf), with at least about 20% and not more than 80% supplied to the fluidized bed zone. In a further embodiment, the gasifying agent is supplied to the gasifier 106 such that the oxygen content in the gasifier 106 is within a controlled range of 0.35 - 0.45 Nm3 / kg (daf), with at least about 35% and not more than 65% supplied to the fluidized bed zone 107. The temperature inside the gasifier 106 is achieved by the content, nature, and quantity of the gasifying agent added to the gasifier 106. There is no need to use an external heat source, and in some embodiments, no external heat source is even used.

[0074] The fluidized bed zone 107 of the gasifier 106 is located in the conical section, operates under a bubbling fluidized bed regime, and contains internally generated solid residues with a particle size distribution ranging from 200 to 1600 microns. The fluidized bed zone 107 operates under controlled conditions where the thermochemical conversion of the granulated feedstock, including partial oxidation and pyrolysis, occurs in a temperature range approximately 250 to 500 degrees Celsius below the ash softening temperature of the feedstock and at an elevated pressure ranging from approximately 200 kPa to 3000 kPa. In particular, operating the gasifier 106 at a high pressure above 1000 kPa enables very high production capacity and high-pressure post-treatment of syngas in a compact unit, thereby reducing the capital and operating costs for the typical downstream processing of syngas into renewable synthetic products such as bio-methanol. In the fluidized bed zone 106, the granulated feedstock undergoes partial oxidation and thermochemical decomposition to produce CO and H2, as well as intermediate products mainly consisting of lower molecular weight hydrocarbon volatiles, heterocyclic compounds, light aromatics, light polycyclic aromatics, aerosols with fly ash / carbon particles, and other solid residues.

[0075] The heavy solid residues generated during partial oxidation and thermochemical decomposition are deposited at the bottom of the fluidized bed zone 106 of the gasifier and leave the gasifier through lines (8a) and (8b) via the bottom product removal device 109, which includes a series of heat exchangers (intercooled screw conveyors and moving beds, etc.), and then enter the lock hopper 110 through line (9). In addition, the heavy solid residues still containing some carbon can be sent to the pressure unit 104 through line (10a), to the cement industry through line (10b), or to the auxiliary boiler 111 through line (10c) to generate high-pressure steam.

[0076] In the gasifier 106, the raw syngas including the tar, volatiles, and aerosol fly ash / carbon particles generated in the fluidized bed zone 107 rises to zone 108 (referred to as the "zone" or "reaction chamber") in the post-gasification zone (i.e., downstream of the fluidized bed zone 107), where the raw syngas is highly enriched and modified at a controlled elevated temperature and pressure, up to 3000 kPa. More specifically, in the post-gasification zone 108, the aerosol partially oxidized and thermochemically decomposed particulate matter contacts the gasifying agent containing oxygen, steam, and CO2 at a controlled rate, providing a controlled temperature range 150 to 300 degrees Celsius below the ash softening temperature of the feedstock to keep the particulate matter non-molten in the post-gasification zone 108. Thus, at these elevated temperatures, the carbon-containing particulate matter in the aerosol is further gasified, increasing the overall carbon conversion rate. Intermediates such as volatiles, tar, and pyrolyzed aerosol fly ash / carbon powder undergo thermochemical conversion, steam cracking, reforming, and oxidation, and are further converted into raw syngas including CO and H2, thereby improving the quality of the generated raw syngas. The enriched raw syngas is quenched in the top part of the gasifier to harden the fine dust particles in the aerosol, thereby minimizing the agglomeration problem or deposition problem in the downstream devices (cyclone separator, quencher, scrubber, etc.).

[0077] Examples of the ash softening points of typical feedstocks include refuse-derived fuel (RDF), whose ash softening point is estimated to be 1130 to 1230 degrees Celsius, and untreated hardwood, whose ash softening point is estimated to range from 1150 to 1600 degrees Celsius. To ensure that the relevant zones of the gasifier 106 have the required temperature, the supply of the gasifying agent will be controlled, which is determined based on the ash softening point of the feedstock that can be determined in the system before processing the feedstock.

[0078] The raw syngas product is withdrawn from the gasifier 106 through a pipeline (11) and passes through a cyclone separator 112, where most of the pyrolyzed aerosol fly ash / carbon with a particle size greater than 10 microns is separated from the enriched raw syngas and recycled back to the fluidized bed zone 107 of the gasifier 106 through a pipeline (12). The syngas product exits the cyclone separator 112 through a pipeline (13) and the raw syngas is cooled by a series of raw gas coolers 113 to generate different levels of saturated steam, where process water (added through a pipeline (14)) is used as a cooling medium to exchange heat in a co-current or counter-current manner, thereby cooling the syngas to a temperature not lower than 250 degrees Celsius. In the above heat recovery stage, part of the generated steam can be superheated in a superheater unit 114 and recycled back to the gasifier 106 through pipelines (15), (15a), and (16) (subsequently passing through pipelines (7), (7a), and (7b)) to be used as the basic fluidizing agent, or injected into the gasifying agent together with oxygen in a multi-layer nozzle. Part of the steam can be sent through a pipeline (15b) to a CO conversion reactor 122.

[0079] The cooled syngas exits the raw gas cooler 113 through pipeline (17) and is further cleaned in the fly ash / carbon dry dust removal device 115 (i.e., the dust removal device), where at least part of the dust is trapped by the candle filter. The filtered dust by-product is then processed in a series of heat exchangers 135 (including an intermediate cooling screw conveyor, a moving bed, etc.) and then enters the lock hopper 134 through pipeline (19). The filtered dust by-product can be removed from the system and reused in the cement industry through pipelines (20) and (20b). Since the filtered dust by-product still contains carbon, it can be returned to the granulator device 103 through pipelines (20) and the return pipeline (20a), thereby improving the overall carbon conversion efficiency of the process. Although not shown in Figure 1 it, another return pipeline can also be included to return the filtered dust by-product to the lock hopper 104.

[0080] The cleaned syngas exits the fly ash / carbon dry dust removal device through pipeline (21) and enters the water shower 116 and the washing device 117, where the syngas product is saturated and further processed. More specifically, part of the cleaned syngas enters the submerged cooler in the water shower 116, whose temperature is at least 150 degrees Celsius and does not exceed 400 degrees Celsius, and contacts the alkaline water from the washing device 117 through pipeline (24b), and the pH of the alkaline water is at least 8 and does not exceed 11, thereby saturating and cooling the syngas. The cooled syngas exiting the submerged cooler enters the raw syngas washing device through pipeline (22). Inside this device, the alkaline water meeting the above conditions enters the Venturi scrubber 118 (located inside the washing device) through pipeline (24a), and then enters the second scrubber 119 (located inside the washing device 117) through pipeline (23). The processed cooled syngas is processed in these devices to remove impurities such as fine particles (if any), heterocyclic aromatic compounds, and at the same time, other pollutants including H2S, COS, NH3, HCN, etc. can also be partially removed. The processed syngas is discharged from the washing device 117 through line (27), and its HCl content is close to zero and the temperature does not exceed 250 degrees Celsius. The acidic water in the water shower 116 and the washing device 117 is led to the wastewater treatment device 120 through line (25) for further removal treatment and recycled to the process through line (26).

[0081] The synthesized gas that has been water-sprayed, saturated, and conditioned is withdrawn from the second scrubber 119 via lines (27) and (27a). The temperature is adjusted in the economic heat exchanger 121, which is an inlet and outlet heat exchanger, and then steam is injected via line (15b) to adjust the water content of the synthesized gas product. Then, the synthesized gas enters the acidic CO conversion fixed-bed reactor 122 via line (28). To enhance the acidic CO conversion reaction, a sulfided Co-Mo-K catalyst based on carbon material is used to adjust the H2 and CO concentrations in the original synthesized gas to meet the downstream process requirements. The temperature in the acidic CO conversion reactor 122 rises, and after passing through the economic heat exchanger 121, the adjusted synthesized gas is discharged from the reactor via line (29) at a temperature not exceeding 450 degrees Celsius. The adjusted synthesized gas enters the carbon monoxide sulfide (COS) hydrolysis unit / reactor 123 via lines (30) and (31) for further treatment, where other acidic gas impurities such as HCN and COS are converted into NH3, H2S, etc., promoting the purification and further modification of the adjusted synthesized gas in the downstream treatment.

[0082] The adjusted synthesized gas is discharged from the COS hydrolysis unit 123 at a temperature not exceeding 200 degrees Celsius and enters a series of knock-out drums 124, 125 via lines (32) and (33), where water, NH3, additional heavy hydrocarbons, and metals (if any) are knocked out. The pollutants removed from the knock-out drums 124, 125 are separated via lines (34) and (38) and sent to the wastewater treatment unit 120 via line (39), where the wastewater is neutralized, decontaminated, purified, and recycled back to the scrubber unit 119 via line (26). Between the knock-out drums 124, 125, the synthesized gas is transmitted via line (35), processed by the adjusted synthesized gas compression unit 126, and then transmitted via lines (36) and (37).

[0083] The adjusted synthesized gas enters and is preheated in a preheater via line (40) to avoid possible tar condensation, passes through the activated carbon mercury guard bed 127 (entering via line (41)), and then via line (42), the synthesized gas is sent to the acidic gas removal and tar scrubbing unit 128, where an absorption process is carried out to remove any unwanted impurities and compounds. More specifically, the above absorption process includes a series of heat exchangers, absorption towers, and flash drums (in Figure 1(not shown in the figure), where cold methanol is used as an absorbent to remove all possible tar contents, including heterocyclic compounds (such as phenol, cresol, quinoline, pyridine), as well as light aromatic compounds (such as toluene, xylene, ethylbenzene) and light polycyclic aromatic hydrocarbons (such as naphthalene, indene, biphenyl, anthracene) and acid gases such as CO2 and H2S. The separated heavier hydrocarbon compounds (such as benzene and naphthalene) can be recycled back to the gasifier 106 through lines (47, 47a), or alternatively sent to the auxiliary boiler through line 47b, thereby improving the thermal efficiency of the entire process. The removed acid gases, mainly containing CO2 and H2S, are sent through line (43) to the CO2 and H2S separation unit 129, where sulfur is separated and removed in the form of elemental sulfur cake through line (44). The separated CO2 is sent through line (45) to the CO2 compression unit 130, thereby increasing the pressure of CO2 to 3000 kPa or 4000 kPa, and partially recycled to the process as a pressurizing agent in the pressure increasing device (i.e., the lock hopper 10) through the recycle lines (46, 46a), and used as a gasifying agent in the fluidized bed zone 107 of the gasifier 106 through the recycle lines (46, 46b), thereby ensuring that the process has a low carbon footprint, is environmentally friendly and cost-effective. Part of the CO2 can be processed through the biological CO2 liquefaction unit 131 through line (49) and then exported.

[0084] The adjusted and purified syngas after being treated by the acid gas removal and tar washing unit 128 is withdrawn through line (48) and pressurized by the compressor / booster unit 132, from about 5000 kPa to 10000 kPa, which is a favorable condition for preparing renewable synthetic products (such as methanol) using clean tar-free syngas as a raw material, and is processed through line (50) in the synthetic product production unit 133 (such as the second-generation biofuel synthesis unit).

[0085] The process and apparatus of the present invention will now be described in further detail.

[0086] The process and apparatus of the present invention can generally be divided into three main stages:

[0087] (1) Pre-gasification - i.e., preparing and treating the raw materials before entering the gasifier.

[0088] (2) Gasification - i.e., gasifying the raw materials in the fluidized bed zone and the post-gasification zone of the gasifier.

[0089] (3) Downstream processing - i.e., treating the raw syngas product produced by the gasifier. This generally includes any processing after the syngas product leaves the gasifier. The raw syngas product is usually processed to optimize its properties and remove impurities, thereby obtaining pure or purer syngas.

[0090] After downstream processing, the purified syngas may undergo further processing to convert it into synthetic products or chemicals.

[0091] Pre-vaporization

[0092] According to the present invention, pre-gasification includes densifying the feedstock, optionally in a densifying device, then pressurizing the densified feedstock in a pressurizing device, and subsequently supplying the densified and pressurized feedstock to a gasifier, optionally to the fluidized bed region of the gasifier.

[0093] The process and apparatus may include any other pre-gasification steps or devices typically associated with an HTW gasifier or other suitable gasifier.

[0094] One of the first steps in the pre-gasification process is to provide the feedstock.

[0095] The process of the present invention is applicable to any suitable feedstock, including biomass and / or carbonaceous solid waste materials. In other embodiments, the feedstock includes biomass. In another embodiment, the feedstock includes carbonaceous solid waste materials. In certain embodiments, the feedstock consists only of biomass, while in other embodiments it consists only of carbonaceous solid waste materials. In further embodiments, the feedstock includes a mixture of biomass and carbonaceous solid waste materials. In certain embodiments, the proportion of the feedstock composed of biomass is in the majority (i.e., greater than 50% by weight), or the proportion of the feedstock composed of carbonaceous solid waste materials is in the majority. In certain embodiments, the feedstock consists only of biomass and carbonaceous solid waste materials, i.e., the feedstock is biomass and carbonaceous solid waste materials. In certain embodiments, the feedstock is mainly composed of biomass and carbonaceous solid waste materials. In certain embodiments, the feedstock includes biomass, carbonaceous solid waste materials, or a combination of biomass and carbonaceous solid waste materials, with a weight of at least 10%, 20%, 30%, 40%, 60%, 70%, 80%, 90%, 95%, or 99% of the total feedstock weight.

[0096] The process of the present invention is capable of processing homogeneous and heterogeneous feedstocks. In certain embodiments, the feedstock is a homogeneous feedstock. In other embodiments, the feedstock is a heterogeneous feedstock. The term "homogeneous feedstock" refers to a material from a single source, such as trees, agricultural waste, wood chips, etc. While "heterogeneous feedstock" refers to a material from multiple sources, such as wood residues from sawmills, textiles, paper, plastics, cardboard, hydrocarbon compounds, and contaminant compounds, etc. The final feedstock may consist of a single type of feedstock, or multiple different types of feedstocks, or a main feedstock and minor components that make up other feedstocks.

[0097] Biomass refers to materials that are commonly classified as biomass, i.e., organic matter, and have their ordinary meaning in the art. Examples of biomass available in the present invention include wood and plants. Carbon-containing solid waste materials are defined as any form of solid waste containing carbonaceous materials and thus have their ordinary meaning in the art. Examples of carbon-containing solid waste include waste such as wood waste, agricultural waste, municipal solid waste (MSW), refuse-derived fuel (RDF), dried sludge, and industrial waste. The above materials can be processed in the present invention either alone or in combination. Possible feedstocks include: RDF, MSW, waste wood (optionally untreated), and hardwoods, which can be processed either alone or in combination. In particular, suitable feedstocks can be selected from RDF alone, MSW alone, a mixture of RDF and MSW, a mixture of RDF and plastics, untreated wood, and hardwoods. A mixture of RDF and MSW is particularly suitable for use. "Carbon-containing" means that the waste contains at least some carbon. In certain embodiments, the carbon content of the carbon-containing solid waste material is at least 25 weight percent, at least 35 weight percent, or at least 50 weight percent (i.e., mostly carbon), based on the total weight of the carbon-containing solid waste material. The term "waste" has its ordinary meaning in the art, e.g., the material is unwanted and / or unusable.

[0098] In this process, various different forms of feedstocks comprising biomass and carbon-containing solid waste materials are suitable feedstocks.

[0099] It has been found particularly advantageous to densify the feedstock before supplying it to the gasification unit. Any known densification technique / method can be used to densify the feedstock. One such densification method is granulation in a granulation unit. Any suitable granulation method and equipment known in the art can be used. Using granulated material is not only beneficial for the gasification process under high-pressure conditions but also provides a feedstock with a higher bulk density than fragmented or non-granulated material. Using granulated flowing material helps in operating under high pressure, achieving two main advantages, namely, a higher feed density results in lower CO2 consumption, which is advantageous for the process, and improves the flowability of the feed material, which can be important when using a lock-hopper gravity system for pressurization. In addition, it is possible to return carbon-containing dust to the granulation unit and remove it from the dry dusting unit, and its return can improve the overall carbon conversion efficiency of the system. It is also possible to premix a small amount of additives into the granules, including but not limited to magnesium compounds, to neutralize impurities such as chlorine, fluorine, and sulfur that are inherently present in the carbon-containing granulated material.

[0100] Another step before gasification is to pressurize the densified feedstock in a pressurization device. Here, "pressurization" means increasing the pressure. The pressurization step can be carried out in any suitable pressurization device that can increase the pressure of the feedstock. For example, a lock hopper system including single or multiple lock hoppers can be used. Any suitable pressurizing agent can be used to pressurize the feedstock. In some embodiments, the pressurizing agent includes CO2. In some embodiments, the pressurizing agent includes CO2 recovered / returned from the syngas product separated in the CO2 separation device. This helps to improve the carbon footprint, environmental friendliness of the process, and makes the process more cost-effective, as described above. Recycling CO2 into the pressurization device (or more generally, the feeding system) also helps to enable the feeding system to operate at a pressure similar to that of the gasification device. The dust separated from the dry dust removal device downstream of the gasification device can also be recycled / returned to the pressurization device for reprocessing, thereby improving the overall carbon conversion efficiency of the process. In some embodiments, the pressure in the pressurization device is between 1000 and 3000 kPa, optionally between 1500 and 2500 kPa. In some embodiments, the pressure in the pressurization device is the same as or similar to the pressure of the gasification device.

[0101] The pressurization device and the densification device generally constitute a so-called feeding system, which can include any other steps or devices known in the art for feeding systems, such as star feeders, crusher devices, and drying devices. In the art, the pressurization device is generally also referred to as a feed handling device.

[0102] It is worth noting that further processing of the feedstock may be carried out between the densification and pressurization steps. However, in some embodiments, pressurization will be carried out directly after the feedstock is densified.

[0103] The pre-gasification process and device also include a device suitable for supplying the densified and pressurized feedstock to the fluidized bed area of the gasification device, such as a feed screw conveyor that is easily understood in the art.

[0104] Vaporization

[0105] According to the present invention, gasification means subjecting the feedstock to gasification treatment in a gasification device using a sufficient amount of gasifying agent. The gasification device includes a fluidized bed area and a post-gasification area located downstream of the fluidized bed area to convert the feedstock into a syngas product.

[0106] Any suitable gasifying agent known in the art can be used. In certain embodiments, the gasifying agent includes oxygen, steam, and carbon dioxide. In certain embodiments, the gasifying agent may also include any other suitable gasifying agent. In certain embodiments, the gasifying agent further includes air. In certain embodiments, the gasifying agent is oxygen, steam, and carbon dioxide, i.e., the gasifying agent does not contain any other major gases (except impurities). The gasifying agent enters the fluidized bed region of the gasification device through any suitable feeding device. In certain embodiments, the gasifying agent includes recycled carbon dioxide from a downstream carbon dioxide separation device. In certain embodiments, carbon dioxide is recycled to the fluidized bed region of the gasification device.

[0107] In certain embodiments, the gasifying agent enters the gasification device at a controlled flow rate, which can be through a single-layer or multi-layer nozzle system, as described in detail below.

[0108] In certain embodiments, the content and amount of the gasifying agent input into the gasification device will depend on the identity, characteristics, and properties of the feedstock. These include properties such as the fixed carbon content, calorific value, ash fusion temperature, metal content, and other impurity levels of the feedstock. In certain embodiments, the provided content and amount of the gasifying agent should be sufficient to partially oxidize and thermochemically decompose the feedstock to obtain high-quality, tar-free syngas, which is understandable in the art. Ultimately, in certain embodiments, the selected gasifying agent should be sufficient to convert the feedstock into a syngas product.

[0109] In certain embodiments, depending on the specific feedstock used in the process, the gasifying agent is supplied to the gasification device such that the oxygen content in the gasification device is within the control range of 0.28 - 0.52 Nm3 / kg (daf) of the feedstock, where at least about 20% and not more than about 80% is supplied to the fluidized bed zone. In a further embodiment, the gasifying agent is supplied to the gasification device such that the oxygen content in the gasification device is within the control range of 0.35 - 0.45 Nm3 / kg (daf) of the feedstock, where at least about 35% and not more than about 65% is supplied to the fluidized bed zone.

[0110] daf or DAF = dry ash-free content, i.e., the weight percentage of dry and ash-free material, calculated as follows:

[0111] daf = 100 / (100 - TM - ash)

[0112] where TM = total moisture content of the feedstock, ash = ash content in the feedstock. TM is calculated according to ISO 18134-1, and ash is calculated according to the ISO 18122 standard.

[0113] In certain embodiments, depending on the specific feedstock used in the process, the gasifying agent is supplied to the gasification unit such that the amount of steam in the gasification unit is within the controlled range of 0.23 - 0.52 Nm3 / kg(daf) of the feedstock, with at least about 40% and not more than about 80% being supplied to the fluidized bed zone. In further embodiments, depending on the specific feedstock used in the process, the gasifying agent is supplied to the gasification unit such that the amount of steam in the gasification unit is within the controlled range of 0.30 - 0.45 Nm3 / kg(daf) of the feedstock, with at least about 50% and not more than about 70% being supplied to the fluidized bed zone.

[0114] The gasification unit is typically an HTW gasification unit, comprising a fluidized bed zone and a post-gasification treatment zone, i.e., these two zones are present in a single reactor (i.e., the gasification unit). The fluidized bed zone is located below the post-gasification treatment zone, i.e., the post-gasification treatment zone is downstream of the fluidized bed zone. The fluidized bed zone has its usual meaning in the art and in HTW gasification, i.e., during operation, the materials therein exhibit fluid properties. In certain embodiments, the bubbling fluidized bed includes internally generated solid residues of the gasification feedstock known as bed material. Generally, the particle size range of the bed material is from about 200 to about 1600 microns.

[0115] The described post-gasification treatment zone also has its usual meaning in the art and in HTW gasification herein. In certain embodiments, the post-gasification treatment zone is a freeboard zone.

[0116] In certain embodiments, the gasification unit includes a conical section. In certain embodiments, the fluidized bed zone is located inside the conical section, and the post-gasification treatment zone is located within the non-conical section above the conical section. In certain embodiments, the angle of the conical section is between 3 and 12 degrees. Arranging the fluidized bed zone in the conical section enables the gas velocity and oxygen supply to remain almost constant along the height of the fluidized bed, thereby enabling control of the process conditions such that uniform bubbles are formed in the fluidized bed zone, enhancing the partial oxidation and pyrolysis of the gasification feedstock. Alternatively, the gasification unit can adopt any suitable gasifier shape or form. In certain embodiments, the gasification unit is a gasification unit with a refractory lining.

[0117] In certain embodiments, the operating temperature of the gasification unit depends on the ash fusion temperature of the feedstock to be gasified. Thus, in certain embodiments, before operating the gasification unit, the ash fusion temperature of the feedstock to be gasified is measured first.

[0118] "Ash fusion temperature" has its usual meaning in the technical field, i.e., the temperature at which the ash particles obtained from the feedstock start to deform (i.e., soften) or melt. The ash fusion temperature mentioned herein is experimentally measured using the standard method CEN / TS15370-1.

[0119] The following are the ash fusion temperatures of some example feedstocks under reducing atmosphere conditions:

[0120]

[0121] The above values were obtained from specific feedstocks that were tested. Generally, the ash fusion temperature range for refuse-derived fuel (RDF) is from 1130 to 1230 degrees Celsius, while the ash fusion temperature range for untreated and hardwood is from 1150 to 1600 degrees Celsius, although impurities therein may cause the ash fusion temperature to exceed these ranges. Therefore, these temperature ranges are provided only as approximate ranges.

[0122] In certain embodiments, operating the gasifier according to the ash fusion temperature of the feedstock can efficiently convert the feedstock into syngas. Operating the process within these temperature ranges has been found to advantageously avoid melting the ash slag in the gasifier and making the particles sticky, which can lead to agglomeration and damage to the fluidized bed.

[0123] In certain embodiments, the biomass and / or carbonaceous solid waste feedstock (as discussed in detail previously) is supplied to the gasifier in particulate form (in the manner discussed in detail previously). In certain embodiments, the feedstock is supplied to the gasifier in the form of a fluidized bed region, i.e., through the feed inlet of the fluidized bed region. In certain embodiments, the feedstock is supplied to the fluidized bed region of the gasifier at up to 3 different feed points. In certain embodiments, there are 3 feed points, while in other embodiments there are 2 feed points, and in still other embodiments there is only 1 feed point.

[0124] In certain embodiments, the gasifying agent is supplied to the gasifier at multiple locations. In certain embodiments, the gasifying agent is supplied to the fluidized bed region and the post-gasification region of the gasifier. In certain embodiments, the gasifying agent is supplied to the gasifier at approximately 2 to 15 locations, optionally 4 to 10 locations, and optionally 5 to 8 locations along with the gasifier.

[0125] In certain embodiments, the gasifying agent is supplied to the gasifier through multiple nozzles. In certain embodiments, the nozzles are located at multiple locations along the gasifier. In certain embodiments, the gasifying agent is supplied to the gasifier at approximately 2 to 15 locations, optionally 4 to 10 locations, and optionally 5 to 8 locations along the gasifier. In certain embodiments, at least one nozzle is located on the side of the gasifier, although the nozzles can also be located at the bottom of the gasifier. The nozzles can be located either at the bottom or on the side of the gasifier.

[0126] In some embodiments, each nozzle is multi-layered. In some embodiments, at least one nozzle is arranged at an acute angle with respect to the horizontal plane of the gasifier. In some embodiments, the nozzle can be a burner nozzle or a lance, although any suitable nozzle can be used. In some embodiments, the nozzle is a multi-layer nozzle as described in EP 2885381 A1. A multi-layer nozzle with at least three coaxially arranged pipes is described in this document, and each pipe defines at least one annular gap. The outermost pipe is designed for heat-conducting steam and has a steam supply point. The central pipe is designed as an annular gap. The innermost pipe is designed for oxygen conduction, with a temperature not exceeding 180 °C and having an oxygen supply point. A temperature sensor is provided inside the innermost pipe, and the temperature sensor extends in front of the opening position of the innermost pipe. The innermost pipe is conical in front of the opening; the opening of the innermost pipe enters the central pipe; and the opening of the central pipe protrudes more with respect to the opening of the outermost pipe. Therefore, the nozzle has a "multi-layer" structure, that is, multiple pipes are arranged coaxially.

[0127] In some embodiments, the nozzle is configured to supply gasifying agent during use so as to generate the desired fluidization in the fluidized bed zone and generate multiple working temperatures in the gasification bed and the post-gasification region, that is, generate multiple temperature sub-regions in the fluidized bed and the post-gasification region.

[0128] In some embodiments, at least one nozzle is arranged at an acute angle with respect to the horizontal plane of the gasifier, that is, an angle is set relative to or away from the horizontal plane. The term "acute angle" used herein adopts its normal meaning, that is, less than 90 degrees and greater than 0 degrees. The horizontal plane is defined in a manner perpendicular to the vertical axis of the gasifier (the vertical axis is defined from the bottom to the top of the gasifier), which is the normal manner related to the gasifier.

[0129] Substantially, at least one nozzle is configured to be located at an angle away from the horizontal plane of the gasifier (either above or below the horizontal plane is possible). In some embodiments, at least one nozzle can also be arranged at an acute angle with respect to the vertical plane or axis of the gasifier. In some embodiments, the angle of the nozzle with respect to the horizontal plane is between 5 and 85 degrees, optionally between 10 and 80 degrees or between 20 and 60 degrees.

[0130] It has been found that setting the nozzle at an angle relative to the horizontal plane of the gasifier, and in certain embodiments using the described nozzle arrangement and multi-layer configuration, can enhance the local transport and reaction mechanisms within the gasifier. This is because the gasifying agent is introduced at an acute angle relative to the horizontal plane of the gasifier. In particular, the angle of the nozzle has advantages in terms of the flame (jet stream). Whenever oxygen (i.e., the gasifying agent) is injected into the gasifier, a flame is observed at the nozzle exit. The length of the flame should not exceed the inner radius (half of the inner diameter) of the gasifier vessel. This is to avoid contact of the flame tip of the nozzle with the inner lining of the gasifier (such as a refractory lining), etc. Thus, the nozzle of the present invention can have a longer flame length, which helps to enhance the cracking of high molecular weight hydrocarbons (such as naphthalene), compared to typical nozzles that are usually arranged on the horizontal plane of the gasifier and usually inject the gasifying agent along the basic horizontal plane within the gasifier. Naphthalene is undesirable in the syngas product, thus improving the quality of the syngas product.

[0131] In certain embodiments, the operating pressure range of the gasifier is about 100 to 3000 kPa or 4000 kPa, optionally about 1000 to 2000 kPa, optionally about 1100 to 1700 kPa, optionally about 1200 to 1400 kPa. In certain embodiments, the elevated pressure enables the compact device to have a very high production capacity. In certain embodiments, the operating pressure of the gasifier is higher than about 1000 kPa. In certain embodiments, an operating pressure higher than about 1000 kPa helps with the post-treatment of syngas at high pressure, thereby reducing the capital cost required for the typical downstream processing of syngas into advanced fuels such as bio-methanol.

[0132] In certain embodiments, the feedstock contacts the gasifying agent in the gasifier, and the gasifying agent includes oxygen, steam, and carbon dioxide, and its temperature in the gasifier is as follows:

[0133] (a) Feed the feedstock to a gasifier that includes a fluidized bed zone and a post-gasification treatment zone.

[0134] (b) In the fluidized bed zone, contact the gasifying agent with the feedstock, maintaining the temperature below the ash softening temperature of the feedstock by about 350 - 400 °C to partially oxidize the feedstock.

[0135] (c) Then, treat at least a portion of the product from step (b) at a higher temperature, which is maintained below the ash softening temperature of the feedstock by about 250 - 350 °C, within the fluidized bed zone.

[0136] (d) Then, treat at least a portion of the product from step (c) at a higher temperature, which is maintained below the ash softening temperature of the feedstock by about 200 - 300 °C, in the post-gasification treatment zone.

[0137] (e) Then, at least a portion of the product of step (d) is treated at a higher temperature that is maintained at about 150 - 250 degrees Celsius below the ash softening temperature of the feedstock, and the treatment is carried out in a post - gasification treatment zone.

[0138] In certain embodiments, each of the above steps occurs substantially in a different sub - region within the gasifier. In this context, the sub - regions referred to are a region within the fluidized bed or the post - gasification treatment zone. In certain embodiments, each subsequent step occurs in a sub - region within the gasifier that is above the sub - region of the previous step, that is, as the feedstock ascends from the fluidized bed zone to the post - gasification treatment zone and until it exits the gasifier (progressing gradually downstream), each step progresses gradually upward within the gasifier. In certain embodiments, the temperature within the gasifier generally increases gradually from the bottom to the top, which is technically common. It should be understood that there may be some temperature overlap at the boundaries of each sub - region, and thus the term "substantially" is used above. Similarly, it should be understood that there may be some similar temperature overlap between the fluidized bed zone and the post - gasification treatment zone.

[0139] In certain embodiments, the temperature between each sub - region increases by at least 5 degrees Celsius, 10 degrees Celsius, 20 degrees Celsius, 30 degrees Celsius, or 50 degrees Celsius.

[0140] In certain embodiments, the controlled addition of the gasifying agent creates the above - mentioned temperature or thermal sub - regions within the gasifier. That is, in certain embodiments, no external heat source is used. In contrast, in certain embodiments, the gasifying agent (including oxygen, steam, and carbon dioxide) is injected into the gasifier in a sufficient form and quantity to create multiple thermal sub - regions. In further embodiments, the gasifying agent is injected into the gasifier in a sufficient form and quantity to effectively oxidize the feedstock and convert it into a syngas product. In further certain embodiments, the gasifying agent is provided in an appropriate form and quantity to create a fluidizing effect within the fluidized bed zone.

[0141] In certain embodiments, the operation of the gasifier further includes cooling at least a portion of the product generated in the above-described sub-region step (step (e)) to a temperature below the temperature in step (e), which temperature does not exceed approximately 200 degrees Celsius above the slag softening temperature of the feedstock, and this step occurs in the gasification post-treatment zone. In certain embodiments, the cooling step occurs in the quench sub-region of the gasification post-treatment zone and is cooled using quench water or process condensate. In certain embodiments, the cooling step occurs in a sub-region above sub-region step (d) of the gasification post-treatment zone. In certain embodiments, the cooling step occurs at the top of the gasification post-treatment zone and the top of the gasifier. In certain embodiments, quench water or process condensate is sprayed in using a nozzle, optionally the nozzle is located within the quench sub-region. In certain embodiments, the temperature in this step is 200 to 300 degrees Celsius lower than the slag softening temperature of the feedstock, optionally 200 to 250 degrees Celsius lower than the slag softening temperature of the feedstock. In certain embodiments, the sub-region is cooled by adding quench water or process condensate, optionally without using a further additional external cooling source. This step quenches the raw syngas in the gasification post-treatment zone, thereby freezing or quenching the sticky particles formed at the high temperatures of the process, thus minimizing related problems, mainly including blockage of downstream process equipment, thereby increasing the availability of the gasifier. Therefore, due to the high temperature and the possible melting of inorganic materials in the suspended carbon containing alkali metal chlorides and metal oxides, etc., the raw syngas passes through the quench sub-region to minimize the problem of coalescence or deposition of molten substances on the walls of the gasification post-treatment zone and downstream devices such as cyclones and raw gas coolers.

[0142] In certain embodiments, the method further comprises removing at least a portion of the bottom product (such as heavy solid residue) produced in sub-region step (b) to the sedimentation sub-region of the fluidized bed zone. In certain embodiments, the method further comprises treating the bottom product in the sedimentation sub-region with a gasifying agent comprising steam and / or CO2. In certain embodiments, the gasifying agent comprises steam, and further, the gasifying agent is steam. In certain embodiments, the treatment is carried out at a temperature lower than the temperature in step (b), and the temperature does not exceed about 400 degrees Celsius below the slag softening temperature of the feedstock. In certain embodiments, the temperature is between about 400 degrees Celsius and 500 degrees Celsius below the slag softening temperature of the feedstock. In certain embodiments, this step occurs in a sub-region below sub-region step (b). In certain embodiments, this step occurs at the bottom of the fluidized bed zone and the bottom of the gasifier. In certain embodiments, the gasifying agent is injected into the sub-region in a form and quantity (in a controlled manner) to generate the desired temperature and fluidization in the sub-region, i.e., without using other external heat sources. In certain embodiments, the bottom product, such as heavy solid residue, is removed from the gasifier through the bottom of the fluidized bed zone. In certain embodiments, the bottom product is treated in a bottom product removal unit, optionally including one or more cooling screw conveyors and / or a moving bed. In certain embodiments, the method comprises recycling at least a portion of the bottom product to a pressurizing unit. In certain embodiments, the apparatus includes a recovery pipeline between the bottom product removal unit and the pressurizing unit, and the recovery pipeline is configured to recycle at least a portion of the bottom product to the pressurizing unit. In certain embodiments, the recovery pipeline is directly connected between the bottom product removal unit and the pressurizing unit. In other embodiments, the bottom product is treated in at least one lock hopper boiler before recycling, so that the recovery pipeline is directly connected between at least one lock hopper boiler and the pressurizing unit. In certain embodiments, at least a portion of the bottom product is sent to the cement industry for reuse. In certain embodiments, at least a portion of the bottom product is sent to an auxiliary boiler, and optionally, it can be used for steam production.

[0143] In certain embodiments, in addition to sub-region steps (b) to (e), the process further comprises a quenching step and a bottom product removal step, and these steps all occur in different hot sub-regions. In one embodiment, the gasifier includes six hot sub-regions, three of which are located in the fluidized bed zone and three are located in the post-gasification zone.

[0144] Those skilled in the art will understand that in certain embodiments, the temperature ranges associated with the steps and / or sub-regions occurring within the gasifier refer to the average temperature within each step and / or sub-region, and in fact, the temperature may be higher and / or lower in certain portions of each step and / or sub-region. The term "average temperature" as used herein has its ordinary meaning within the technical field, referring to the average temperature of each step and / or sub-region, and it will be understood that there may be temperatures above / below the average temperature within each step and / or sub-region.

[0145] For the avoidance of doubt, in other embodiments, the temperature ranges expressed herein may refer to absolute temperature ranges rather than average temperature ranges.

[0146] In certain embodiments, the residence time in the fluidized bed region is at least about 8 minutes. In certain embodiments, the residence time is from about 8 minutes to about 90 minutes, optionally from about 15 minutes to about 75 minutes, optionally from about 25 minutes to about 60 minutes, optionally from about 35 minutes to about 45 minutes.

[0147] In certain embodiments, the residence time in the post-gasification region is at least about 7 seconds, optionally at least about 10 seconds, optionally at least about 12 seconds, optionally at least about 15 seconds. In certain embodiments, the residence time in the post-gasification region does not exceed about 20 seconds, optionally does not exceed about 15 seconds, optionally does not exceed about 10 seconds. A longer residence time in the post-gasification region helps to improve the thermal decomposition of heavy hydrocarbons (including tar), thereby helping to reduce the tar content in the syngas product.

[0148] In certain embodiments, no external catalyst is added to the system, i.e., the gasification unit is operated without adding an external (or fresh) catalyst. This means that no external catalyst is specifically added to the gasification unit during operation. Instead, in this embodiment, the ash material in the feedstock is essentially used as a catalyst. In this regard, the bottom product of this process usually contains both ash and carbon, and the ash contains many different materials such as aluminum, iron, nickel, etc., which act as catalysts. This helps to reduce operating costs and makes the process operation simpler because externally added catalysts may be quickly contaminated (especially by impurities in the feedstock) and are difficult to handle and reuse.

[0149] By adding a gasifying agent in the fluidized bed region and the post-gasification region (optionally an HTW gasification unit) of the gasification unit, the feedstock is subjected to thermochemical conversion under the above conditions. The feedstock is converted into raw syngas, i.e., the syngas product, during the thermochemical conversion process. After the syngas product leaves the gasification unit, it will undergo downstream processing.

[0150] Downstream processing

[0151] After the synthesis gas product is produced in the gasification device, it will undergo various downstream processing steps to recover pure or purer synthesis gas (hereinafter simply referred to as "synthesis gas"). This may include any processing steps aimed at purifying, removing impurities, cleaning, and conditioning the synthesis gas product for conversion into synthetic products, as well as other known processing methods for the raw synthesis gas.

[0152] In this article, the term "recovered synthesis gas" refers to the downstream processing of the raw synthesis gas, which is easily understood in the professional field. Downstream processing generally refers to a series of steps that occur below the gasification device and are aimed at purifying or preparing the synthesis gas for conversion into synthetic products. The "processing system" mentioned in this article refers to the equipment used for the downstream processing of the raw synthesis gas.

[0153] In some embodiments, the downstream processing of the synthesis gas product produced in the gasification device is carried out directly after the product leaves the gasification device. In other embodiments, there may be intermediate steps or processes between the product leaving the gasification device and entering the downstream processing stage.

[0154] In some embodiments, the downstream processing includes passing the synthesis gas product through at least one cyclone separator to remove suspended dust. As understood in the professional field, dust is usually generated during the gasification process, and in some embodiments, at least a part of the dust will be removed in the cyclone separator. In some embodiments, the cyclone separator can remove most (greater than 50 weight percentage) of the suspended dust. In some embodiments, the cyclone separator can remove most (greater than 50 weight percentage) of the pyrolysis fly ash / carbon powder with a particle size greater than 10 microns. Any suitable cyclone separator equipment applicable to the gasification process can be used. In some embodiments, the cyclone separator includes a reflux pipeline that directly returns the separated material (i.e., dust) to the gasification device, optionally to the fluidized bed area of the gasification device. This helps to improve the carbon conversion efficiency of the system and process. In some embodiments, the reflux pipeline is located at the bottom of the cyclone separator. In some embodiments, the synthesis gas product is directly processed by the cyclone separator after leaving the gasification device, that is, the cyclone separator is the first post-treatment step and is located directly downstream of the gasification device.

[0155] In some embodiments, downstream processing includes processing in at least one raw gas cooler. In some embodiments, at least one raw gas cooler is located directly downstream of the cyclone separator. The raw gas cooler is configured to cool the syngas product and generate saturated steam. In some embodiments, process water is added to the raw gas cooler in a co-current or counter-current manner as a cooling medium. In some embodiments, the syngas product is cooled to a temperature of not less than 250 °C. In some embodiments, the system includes a reflux pipeline for returning at least a portion of the steam to the gasification unit. In some embodiments, the reflux pipeline is connected to a superheater that superheats the returned steam. In some embodiments, the steam returns to the fluidized bed region of the gasification unit and serves as a fluidizing agent or gasifying agent.

[0156] In certain embodiments, downstream processing includes processing in at least one dry dust removal unit, such as a dry dust removal candle filter or a fly ash / carbon dust removal unit (such as a unique dry dust removal candle filter). Dry dust removal candle filters are common in the art. In certain embodiments, the dry dust removal unit is located directly downstream of at least one raw gas cooler. In certain embodiments, the dry dust removal unit includes a candle filter designed to capture dust and perform dust removal. In certain embodiments, any device suitable for filtering dry dust can be used. In other embodiments, the filter can be a dust removal filter element. In certain embodiments, the dry dust removal unit includes a return pipeline for recycling at least a portion of the filtered dust to the densification step (i.e., the densification device, optionally a granulator device), and / or a return pipeline for recycling at least a portion of the filtered dry dust to the pressurization step (i.e., the pressurization device, optionally a lock hopper system). In certain embodiments, the recycling system includes a return pipeline and one or more lock hoppers and dust removal equipment to process the dust after dust removal before recycling it to the densification and / or pressurization steps. In certain embodiments, the return pipeline is directly connected between the dry dust removal filter and the pressurization and / or densification device. In other embodiments, the separated dry dust is processed through a lock hopper before recycling. In this embodiment, the lock hopper is located between the dry dust removal filter and the pressurization and / or densification device such that the return pipeline is directly connected between the lock hopper and the pressurization and / or densification device. The return pipeline helps to improve the carbon conversion efficiency of the system because the filtered dry dust still contains some carbon. In certain embodiments, at least 10 weight percent of the filtered dust is recycled to the densification and / or pressurization step, optionally 20 weight percent, optionally 30 weight percent, optionally 40 weight percent, optionally 50 weight percent, optionally 60 weight percent, optionally 70 weight percent, optionally 80 weight percent, optionally 85 weight percent, based on the total weight of the dust filtered from the syngas product. In certain embodiments, at least a portion of the filtered dust is removed and sent to the cement industry for further use.

[0157] In certain embodiments, downstream processing includes processing in a cooling and washing unit. In certain embodiments, the cooling and washing unit is located directly downstream of the dry dust removal unit. In certain embodiments, the syngas product is cooled, saturated, washed, and conditioned in the cooling and washing unit. In certain embodiments, the cooling and washing unit includes a cooler unit and a washing unit. Any suitable equipment can be used to cool and wash the syngas product. In certain embodiments, the cooler includes an immersion cooler. In certain embodiments, the temperature of the syngas product entering the cooler is between about 150 - 400 degrees Celsius. In certain embodiments, the syngas product is contacted with alkaline water having a pH between about 8 and 11. In certain embodiments, the syngas product is cooled and saturated in the cooler. In certain embodiments, the syngas product is processed in the cooler and then in the washing unit. In certain embodiments, the cooled syngas product is contacted with alkaline water having a pH of about 8 to 11 in the washing unit, optionally removing impurities such as fine particles, heterocyclic aromatic compounds, and other contaminants including H2S, COS, NH3, HCN, etc. In certain embodiments, when the syngas product exits the cooling and washing unit, its HCl content is close to zero, for example less than 1 weight percent, optionally less than 0.1 weight percent, optionally less than 0.01 weight percent, optionally less than 0.001 weight percent, optionally zero weight percent, based on the total weight of the syngas product. In certain embodiments, the syngas product is processed in the washing unit such that its temperature when exiting the washing unit is not greater than about 250 degrees Celsius.

[0158] In certain embodiments, downstream processing includes adjusting the proportions of the components in the syngas product. In certain embodiments, this occurs in a CO conversion reactor. In certain embodiments, adjusting the component proportions includes adjusting the H2 and CO concentrations in the syngas product, for example, to better prepare for subsequent conversion to synthesis products. In certain embodiments, the adjustment step occurs directly downstream of a cooling and washing unit. In certain embodiments, the syngas product is processed in a heat exchanger to adjust its temperature before entering the CO conversion reactor. In certain embodiments, steam is added to the syngas product before it enters the CO conversion reactor to optimize the water content. In certain embodiments, a Co-Mo-K catalyst is used in the CO conversion reactor to adjust the CO and H2 concentrations of the syngas product. In certain embodiments, the temperature at which the syngas product exits the CO conversion reactor is not greater than about 450 degrees Celsius. In certain embodiments, directly downstream of the CO conversion reactor, the syngas product is processed in a COS (carbonyl sulfide) hydrolysis reactor, where other acidic gas impurities such as HCN and COS are converted to NH3 and H2S. In certain embodiments, the temperature at which the adjusted syngas product exits the COS hydrolysis unit is not greater than about 200 degrees Celsius. In certain embodiments, directly downstream of the COS hydrolysis reactor, the syngas product is processed in a plurality of knock-out drums to remove water, NH3, additional heavy hydrocarbons, and metals.

[0159] In certain embodiments, downstream processing includes treating the syngas product in an active mercury guard bed. In certain embodiments, this step occurs directly downstream of the adjustment step.

[0160] In certain embodiments, downstream processing includes separating at least a portion of the CO2 from the syngas product in at least one CO2 separation device. In certain embodiments, this step occurs directly downstream of the active mercury guard bed. In certain embodiments, at least 5 weight percent of the CO2 in the syngas product is separated out, optionally at least 10 weight percent, 20 weight percent, 30 weight percent, 40 weight percent, 50 weight percent, 60 weight percent, 70 weight percent, 80 weight percent, 90 weight percent, 95 weight percent, more than 99 weight percent, based on the total weight of the CO2 in the syngas product.

[0161] In certain embodiments, the system includes a reflux line between at least one CO2 separation device and a pressurizing device (such as at least one lock hopper), and a second reflux line between at least one CO2 separation device and a gasifier (such as its fluidized bed region), the reflux lines being configured to recycle at least a portion of the separated CO2 into the pressurizing device and the gasifier. Thus, in this embodiment, there are at least two separate reflux lines, although they may initially be a single reflux line that divides into two reflux lines, and thus, different portions of the CO2 are returned to the pressurizing device and the gasifier. In certain embodiments, the reflux lines are located directly between at least one CO2 separation device and the pressurizing device and the gasifier, i.e., there are no other devices between at least one CO2 separation device and the pressurizing device and the gasifier. In such an embodiment, the process includes recycling CO2 directly from the CO2 separation device into the pressurizing device and the gasifier. In certain embodiments, at least one device between the reflux lines is located between the CO2 separation device and the pressurizing device and the gasifier.

[0162] In certain embodiments, generally at least 5 wt% of the CO2 is recycled into the pressurizing device and the gasifier, optionally at least 10 wt%, optionally at least 20 wt%, optionally at least 30 wt%, optionally at least 40 wt%, optionally at least 50 wt%, optionally at least 60 wt%, optionally at least 70 wt%, optionally at least 80 wt%, optionally at least 90 wt%, optionally at least 95 wt%, optionally at least 99 wt%, based on the total weight of the CO2 separated from the syngas product. In certain embodiments, the process includes contacting the feedstock with the recycled CO2 in the gasifier, i.e., the recycled CO2 acts as a gasifying agent in the gasifier. In certain embodiments, the recycled CO2 acts as a pressurizing agent in the pressurizing device. In certain embodiments, the material recycled from at least one CO2 separation device into the pressurizing device and the gasifier contains at least 50 wt% of CO2, optionally at least 60 wt%, optionally at least 70 wt%, optionally at least 80 wt%, optionally at least 90 wt%, optionally at least 95 wt%, optionally at least 99 wt%, based on the total weight of the material recycled from at least one CO2 separation device.

[0163] In certain embodiments, at least one CO2 separation device includes an acid gas removal and tar scrubbing device. In certain embodiments, the acid gas removal and tar scrubbing device is located directly downstream of the activated mercury guard bed. In certain embodiments, this step includes using an absorbent, such as cold methanol, to remove the tar content in the syngas product. In certain embodiments, acid gas is removed from the device, and the removed acid gas includes most of the CO2 and H2S (i.e., at least 50% by weight based on the total weight of the removed acid gas).

[0164] In certain embodiments, at least one CO2 separation device includes a CO2 and H2S separation device, and optionally also includes an acid gas removal and tar scrubbing device. In certain embodiments, the removed acid gas is subsequently processed in at least one CO2 and H2S separation device. In certain embodiments, the CO2 and H2S separation device separates at least part of the sulfur cake and removes it from the system. In certain embodiments, the CO2 and H2S separation device separates CO2 from the removed acid gas.

[0165] In certain embodiments, at least one CO2 separation device further includes a CO2 compression device, and optionally also includes an acid gas removal and tar scrubbing device and a CO2 and H2S separation device. In certain embodiments, the CO2 compression device is configured to compress at least part of the separated CO2, optionally after being processed by the acid gas removal and tar scrubbing device and the CO2 and H2S separation device. In certain embodiments, the recycle pipeline is directly located between the CO2 compression device and the pressurization device and the gasifier. In other embodiments, the recycle pipeline is directly located between the CO2 and H2S separation device and the pressurization device and the gasifier.

[0166] In certain embodiments, the cleaned syngas exits from the CO2 separation device, particularly the acid gas removal and tar scrubbing device, and is transferred through a pressure boosting device, optionally as the last step of downstream processing, to increase the pressure of the syngas to at least 10,000 kPa (optionally from a previous pressure of at least 5,000 kPa).

[0167] As previously mentioned, recycling CO2 to the pressurization device and the gasifier helps improve the carbon conversion efficiency of the system.

[0168] In certain embodiments, after recovering the syngas from the downstream processing step, the syngas can be further processed into any useful synthetic products and / or chemicals that are typically prepared from syngas. In certain embodiments, the syngas is converted into synthetic fuels or chemicals according to any syngas conversion methods or technologies known in the art (such as Fischer-Tropsch conversion). These products can be described as renewable synthetic products or renewable synthetic fuels and chemicals. Examples of such synthetic products include bio-methanol, synthetic natural gas, and / or Fischer-Tropsch synthetic fuels.

[0169] In certain embodiments, converting syngas into synthetic products such as more useful synthetic fuels includes recycling the off-gas generated during the conversion of syngas into synthetic products by converting the off-gas into syngas and returning the syngas to the step of converting syngas into synthetic fuels. This method is explained in DE 102013103356 A1. During the conversion into synthetic products, off-gas or waste gas containing components such as carbon monoxide, hydrogen, methane, and higher hydrocarbons is removed and then processed in a separate treatment device, such as an autothermal reformer (ATR), to convert this off-gas back into pure syngas. Then, this pure syngas can be returned for conversion into synthetic products, thus helping to improve the conversion efficiency of the overall process.

[0170] Based on the processes and apparatuses described herein, successful tests have been conducted. The feedstocks for the tests included the following: i) waste wood pellets (WW), ii) 75% refuse-derived fuel (RDF) / 25% WW, iii) 50% RDF / 50% WW, iv) 25% RDF / 75% WW, and v) 100% RDF. The test results showed that the feedstocks were efficiently converted into syngas, with a carbon conversion efficiency (CCE) of approximately 95% (where CCE represents the percentage of the total carbon in the gasifier feedstock that was successfully converted into carbon-containing product gases such as CO, CO2, CH4, C2H2, C2H4, C2H6, C6H6, and C10H8).

[0171] Surprisingly, it has been found that due to the use of dense granular feedstocks made of biomass and / or carbon-containing solid waste in the current HTW gasification process, the feedstocks can be introduced into the gasifier more simply. Without wishing to be bound by a particular theory, it is believed that this effect is achieved by avoiding obstructions such as Figure 2 the bridges and voids shown. By densifying the feedstock, such as by granulation, the density of the feedstock can be increased from approximately 150 kg / m³ (loose state) to approximately 450 - 550 kg / m³ (granular state). Thereby, the gas (usually CO2) required to pressurize the feedstock in the lock-hopper system is greatly reduced, having a very positive impact on the gasification process within the HTW reactor.

[0172] In addition, densification of the waste / biomass provides a higher carbon density and a higher raw material energy density, and thus provides a higher effective syngas (i.e., CO + H2) flow rate, matching the higher design production capacity of the biofuel production route. In particular, the inventors have found that the chemical energy is retained in the particulate densified feedstock of biomass and / or carbon-containing solid waste used in the present invention as compared to other pretreatment routes. There are main pretreatment routes for industrial-scale production of biofuels through pressurized gasification processes. The inventors surprisingly found that: (1) granulation treatment can process 100% of the chemical energy of the feedstock in the gasifier; (2) drying treatment can only process 87% of the chemical energy of the feedstock, and the rest is lost during drying; (3) pyrolysis treatment can only process about 70% of the chemical energy of the feedstock, and the rest is lost during pyrolysis. Therefore, using the particles described herein as the feedstock is beneficial for gasification using chemical energy.

[0173] In addition, it has surprisingly been found that, when performing the above tests, the total energy required for densification of the feedstock, granulation treatment and subsequent gasification at high pressure (e.g., above 10 bar), and compression of the syngas is less than the energy required for gasification at atmospheric pressure and pressurizing the syngas from atmospheric pressure to the biofuel synthesis pressure.

[0174] The order of process steps described herein is provided by way of example only (unless a particular order is required by the explicit wording of the steps), but these steps can be carried out in any suitable order or simultaneously where appropriate. In addition, individual steps can be added, replaced or deleted in any process without departing from the scope of the subject matter described herein. For example, even if in the claims herein the second step follows the first step, it should be understood that further steps can be carried out between the first and second steps according to expertise, unless the wording of the claim explicitly requires no intervening steps.

[0175] The above description of the preferred embodiments is by way of example only, and various modifications may be made by those skilled in the art. The foregoing includes examples of one or more embodiments. Of course, it is not possible to describe every possible modification and variation for the purpose of describing the above aspects, but those of ordinary skill in the art can recognize that many further modifications and permutations of the various aspects are possible. Accordingly, the aspects described are intended to cover all such modifications, variations and changes that fall within the scope of the appended claims.

Claims

1. A process for converting a feedstock comprising biomass and / or carbonaceous solid waste materials into syngas, the process comprising the following steps: (a) Compressing the feedstock; (b) Pressurizing the compressed feedstock in a pressurizing device; (c) Feeding the feedstock from step (b) into a gasifier, optionally a high-temperature Winkler (HTW) gasifier, which gasifier comprises a fluidized bed zone and a post-gasification zone; (d) Converting the feedstock into a syngas product by contacting the feedstock with a gasifying agent in the gasifier; and (e) Recovering the syngas from the product produced in step (d), wherein recovering the syngas comprises separating at least a portion of carbon dioxide from the product produced in step (d), recycling at least a portion of the separated carbon dioxide back to the pressurizing device, and recycling at least another portion of the separated carbon dioxide back to the gasifier.

2. The process according to claim 1, wherein step (d) comprises contacting the feedstock with a gasifying agent in the fluidized bed zone, the gasifying agent optionally comprising steam, oxygen and carbon dioxide, and partially oxidizing the feedstock at an average temperature of about 250 - 500 °C at the ash fusion temperature of the feedstock.

3. The process according to claim 2, wherein step (d) comprises contacting the partially oxidized feedstock with a gasifying agent in the post-gasification zone at an average temperature of about 150 - 300 °C at the ash fusion temperature of the feedstock, the gasifying agent optionally comprising steam, oxygen and carbon dioxide.

4. The process according to any one of the preceding claims, further comprising operating the fluidized bed and the post-gasification zone at a pressure between about 200 kPa and about 3000 or about 200 kPa and about 4000 kPa, optionally at a pressure between about 1000 kPa and about 3000 or about 1000 kPa and about 4000 kPa, and optionally the gasifier is a refractory-lined reactor.

5. The process according to any one of the preceding claims, wherein the densification of the feedstock in step (a) is carried out in a densifying device, optionally wherein the densification comprises granulating the feedstock in a granulating machine device.

6. The process according to any one of the preceding claims, wherein recovering the syngas further comprises: (e1) Dry-filtering and cleaning the product produced in step (d); (e2) Quenching, saturating, washing and treating the product produced in step (e1); and (e3) Treating the product in step (e2) to adjust the proportion of each component in the product.

7. The process according to claim 6, wherein the temperature of the product entering the quenching and saturating step is at least 150 degrees Celsius but does not exceed 400 degrees Celsius.

8. The process according to claims 6 and 7, wherein quenching and saturating comprises contacting the product with alkaline water having a pH value between about 8 and 11.

9. The process according to claims 6 to 8, wherein the product leaving step (e2) has a zero chloride content and a temperature not exceeding about 250 degrees Celsius.

10. The process according to any one of the preceding claims, wherein recovering the syngas further comprises filtering dust from the product in a dry dust removal device.

11. The process according to claim 10 further comprises recycling at least a portion of the filtered dry dust to step (a) and / or recycling at least a portion of the filtered dry dust to step (b).

12. A process for converting a feedstock comprising biomass and / or carbonaceous solid waste material into synthetic products and / or chemicals, the process comprising: converting a feedstock comprising biomass and / or carbonaceous solid waste material into synthesis gas according to the process of any one of claims 1 to 11; and converting the synthesis gas into synthetic products and / or chemicals.

13. The process according to claim 12 further comprises recycling the tail gas by converting the tail gas into synthesis gas and returning the synthesis gas to the step of converting the synthesis gas into synthetic products and / or chemicals, the tail gas being generated during the conversion of the synthesis gas into synthetic products and / or chemicals.

14. An apparatus for converting a feedstock comprising biomass and / or carbonaceous solid waste material into synthesis gas, the apparatus comprising: a feed system comprising a densification device and a pressurization device; a gasifier, optionally a high temperature Winkler (HTW) gasifier, comprising a fluidized bed zone and a post-gasification zone for thermally converting the feedstock into synthesis gas products, wherein the feed system is configured to deliver the feedstock to the gasifier; and a treatment system downstream of the gasifier configured to recover synthesis gas from the synthesis gas products, wherein the treatment system comprises at least one CO2 separation device configured to separate CO2 from the synthesis products; wherein the treatment system further comprises a recovery line between at least one CO2 separation device and the pressurization device and a second recovery line between at least one CO2 separation device and the gasifier, the recovery lines being configured to recycle at least a portion of the separated CO2 to the pressurization device and the gasifier, and wherein, optionally, the fluidized bed and the post-gasification zone are configured to operate at a pressure between about 200 kPa and 3000 kPa or between about 200 kPa and 4000 kPa, more optionally at a pressure of about 1000 kPa to 3000 kPa or about 1000 kPa to 4000 kPa.

15. The apparatus according to claim 14, wherein the treatment system further comprises a dry dust removal device configured to filter dust from the products, and there is also a recovery line between the dry dust removal device and the densification device and / or the pressurization device, the recovery line being configured to recycle at least a portion of the filtered dust to the densification device and / or the pressurization device.

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