Method of converting a carbonaceous material into synthesis gas

Abstract

It is provided method of converting a carbonaceous material into synthesis gas comprising drying a shredded carbonaceous material producing a dried material; treating the dried material in a thermal pre-treatment unit (TPTU), generating a carbonized solids stream, a TPTU liquid stream and a waste gas stream; milling the carbonized solids in a first milling step producing milled carbonized solids; optionally removing metal and non-metal inert from the milled carbonized solids; grinding the milled carbonized solids in a second milling step, producing a carbonized material powder; mixing the TPTU liquid with the carbonized material powder, producing a slurry; gasifying the slurry in a gasifying process at a temperature above 1000°C, producing syngas.

Description

METHOD OF CONVERTING A CARBONACEOUS MATERIALINTO SYNTHESIS GASCROSS-REFERENCE TO RELATED APPLICATION

[0001] The present application is claiming priority from U.S. Provisional Application No. 63 / 749,206 filed January 24, 2025, the content of which is hereby incorporated by reference in their entirety.TECHNICAL FIELD

[0002] It is provided a method of converting a carbonaceous material into synthesis gas comprising producing a slurry.BACKGROUND

[0003] Synthesis gas, also called syngas, is a fuel gas or reactive mixture comprising primarily of carbon monoxide (CO), carbon dioxide (CO2) and hydrogen (H2). When it is a desired product, it may also be comprised of methane (CH4) by changing operating temperature.

[0004] Syngas can be produced from many sources, including biomass, or virtually any carbonaceous material, by reaction with steam (steam reforming), carbon dioxide (dry reforming), air (partial oxidation), oxygen (partial oxidation) or any mixture of the reactants listed. Syngas is a crucial intermediate resource for production of hydrogen, ammonia, and methanol for example. Utilization of syngas in internal combustion engines and as a renewable energy resource is ongoing extensive investigation.

[0005] Converting carbonaceous materials and waste into synthesis gas can be achieved with gasification techniques. The gasification provides a crude syngas which can includesinclude impurities such as ammonia (NH3), hydrogen cyanide (HCN), sulfur (as hydrogen sulfide (H2S) and carbonyl sulfide (COS), chlorine (as HCI), fine ashes (in the form of particles containing metals and metal salts) and volatile metals. At temperature below 1000°C and even below 1200°C, the gasification also generates low molecular weight alkanes and alkenes, aromatic tars (NBTX; naphthalene, benzene, toluene and xylene), tars (including PAH), and char (solid particulates typically above 0.001 mm and containing metals, salts and mostly carbon). Such impurities, however, limit the ability of the syngas to be used as a fuel or to be employed in the synthesis of other useful materials without a cleaning process.

[0006] There are many types of gasifier apparatus that already exist and are used in various processes, including plasma assisted gasification, staged gasification and / or indirect gasification processes. Other examples include fixed bed, moving bed, fluidized bed, circulating fluidized bed and entrained-flow gasifiers (EFG). The entrained flow gasifier typically works at a higher outlet temperature than the other gasifiers. It produces a syngas with less residual char and tar than any other type of gasifier and melts the feedstock mineral material into a glass-like material. One drawback of the entrained-flow gasifier is the limitation in the solid material feeding preparation. Two forms of feed are generally employed in entrained-flow gasifiers; either very fine particle injection with a conveying gas (pneumatic conveying) or mechanical device, or injection of a liquid-solid slurry made of very fine solids and a liquid which can be water and / or a carbonaceous liquid (a surfactant and / or stabilizing agent can be added in small amount to the slurry).

[0007] Untreated waste and many untreated biomass materials require extensive grinding and / or pre-treatment to achieve a fine and homogeneous particle feed size. In addition, most types of waste, biomass, non-coal like carbonaceous solid materials and / or very low-density materials produce a fluffy feed instead of finely divided particles. It is accepted that waste and biomass can undergo a shredding and / or grinding process that produces coarse sized particles, many orders of magnitude bigger than those required for an entrained-flow gasifier.

[0008] One way to overcome the challenges associated with the feeding of waste and / or biomass in an entrained flow gasifier is to replace a small portion of an existing feed, slurry or coal, of an existing plant. This co-feeding approach has been demonstrated on a commercial scale (Nuon Power’s IGCC) where biomass was mixed up to 30% with coal to be dry-fed in a gasifier to produce syngas.

[0009] Another issue with the entrained-flow gasifier is the low residence time in the reactor, consisting of a few seconds to less than a second. This requires a narrow lower range of feedstock particle size / density distribution, otherwise the conversion efficiency to syngas of such feedstock would be low, resulting in the production of more undesirable char and tar in the produced syngas.

[0010] Contrary to coal feedstocks which have a relatively narrow range of particle density / size, biomass, waste and mixtures of both have a very broad range of particle diameter and bulk density. Entrained-flow gasifiers (or thermal reformer) can operate at high temperatures and handle melted mineral only when the particle size is small, in themicron range, and when the mass, particle size distribution, and residual mineral content is uniform.

[0011] A thermal pre-treatment can be successfully applied to biomass or plastics with existing technologies in order to produce a carbonized solid and / or oil with a higher density and / or heating value but its successful application to a mixture of biomass and plastics such as municipal solid waste (MSW) is still to be demonstrated. Moreover, many existing technologies for the thermal treatment of biomass or plastics operate in conditions where a lot of mass, including carbon and hydrogen, is lost in the waste gas and is burnt. The thermal pre-treatment’s main objective is to enable process improvements for the gasification step, which will result in higher gasification efficiency and higher syngas yield (i.e. H2and CO). In the production of biofuel (e.g. methanol or SAF), the carbon intensity (i.e. kilograms of CO2equivalent per Megajoules of product) of the overall process is critical. To improve the production cost and carbon intensity, it is very important for a biofuel project, to maximize syngas yield (thus maximizing the amount of carbon ending up in the final product) and to minimize the utilization of fossil fuels or other energy sources that are greenhouse gas intensive. Table 1 shows that a thermal pre-treatment-, as described herein, coupled with an entrained flow gasifier can achieve a higher theoretical yield than a reference yield of a bubbling bed gasifier coupled with a thermal reformer (similar to an entrained flow gasifier) but when the severity (expressed as mass loss) of the thermal pre-treatment keeps increasing, the syngas yield of the thermal pre-treatment coupled with an entrained flow gasifier drops below the reference yield. The yields shown in Table 1 assumes that the products of the thermal pre-treatment can be processed into a slurry and fed to an entrained flow gasifier, but this is not possible when the ratio of carbonized solids to TPTU liquid is too high, which is the case at very low severity (e.g. below 25% mass loss, d.b.). Therefore, the operating conditions of the TPTU and its integration with the drying, milling, slurry preparation and gasification steps are optimized to maximize the net syngas yield as shown in Table 1. The thermal pre-treatment of a carbonaceous material at low to moderate severity (mass loss below 40%, dry basis) also enables some process improvements for a gasifying step comprising a bubbling bed gasifier coupled with a thermal reformer which can also result in higher syngas yield but to a lesser extent when compared to an entrained flow gasifier.Table 1: Theoretical yield vs Thermal Pre-Treatment Severity (i.e. Mass loss')Extrapolated case

[0012] Considering the current available technologies, it is not possible to gasify a carbonaceous materials comprising a fraction of biomass and / or plastic in an entrained flow gasifier with a carbon to syngas conversion as high or close to theoretically possible with an entrained flow gasifier.

[0013] There is thus a need to be provided with a means and / or process for the gasification of course to upgrade a carbonaceous material with a fraction of plastic and / or biomass to produce an organic liquid for the preparation of a slurry suitable for an entrained flow gasification while also improving the syngas yield.SUMMARY

[0014] It is provided a method of converting a carbonaceous material into an optimized synthesis gas comprising optionally drying a shredded carbonaceous material producing a dried material; treating said dried material or shredded carbonaceous material at a temperature above 300°C in a thermal pre-treatment unit (TPTU), generating a carbonized solids stream, a waste gas and a TPTU liquid stream; milling the carbonized solids in a first milling step producing milled carbonized solids or carbonized material powder; mixing the TPTU liquid with the carbonized material powder, producing a slurry; gasifying the slurry in a gasifying process at a temperature above 1000°C, producing a scrubbed syngas, and solid residues; and removing CO2and H2S from the scrubbed syngas producing the optimized synthesis gas or sweet syngas.

[0015] In an embodiment, the method provided herewith further comprises the step of removing metal and non-metal inert from said milled carbonized solids; grinding the milled carbonized solids in a second milling step, producing the carbonized material powder.

[0016] In an embodiment, the method provided herewith further comprises the step of treating said dried material in a primary TPTU reactor, creating a first stage TPTU gas stream in addition to a baked solids stream.

[0017] In another embodiment, the method provided herewith further comprises the steps of shifting CO in a portion of the sweet syngas in a water gas shift unit, removing produced CO2in a CO2absorption unit and mixing with the un-shifted portion of the sweet syngas, producing a balanced syngas; and converting said balanced syngas into methanol in a methanol reactor.

[0018] In an embodiment, the baked solids generated in step a’) are classified, creating a fine and brittle fraction.

[0019] In a further embodiment, the baked solids are classified in an aerodynamic classifier.

[0020] In an embodiment, the fine and brittle fraction are introduced with the carbonized solids in the milling step or with the milled carbonized solids in the second milling step.

[0021] In an embodiment, the TPTU comprises a condenser to condense the TPTU liquid.

[0022] In another embodiment, the condenser is a direct contact heat exchanger or an indirect heat exchanger.

[0023] In an embodiment, the first stage TPTU gas and / or waste gas are burnt producing heat which is recovered in an exchanger or indirectly in the TPTU reactor and / or primary TPTU reactor.

[0024] In another embodiment, the balanced syngas is converted into Fischer-Tropsch products, ethanol, synthetic or substitute natural gas.

[0025] In an embodiment, the heat is used for the TPTU.

[0026] In another embodiment, the carbonized solids are milled to a particle size of 10 mm and less.

[0027] In an embodiment, the milled carbonized solids are ground to a particle size of 1 mm and less.

[0028] In another embodiment, the slurry is gasified in an entrained flow gasifier followed by a quench, heat recovery exchangers and a water scrubber.

[0029] In an embodiment, the entrained flow gasifier is preceded by a fluidized bed gasifier operating at a temperature below 1000°C.

[0030] In a further embodiment, the baked solids and / or carbonized solids and the TPTU liquid are fed directly in a fluidized bed gasifier followed by a thermal reformer.

[0031] In an embodiment, the CO2and H2S are removed from the syngas by absorption using a CO2selective solvent.

[0032] In another embodiment, the CO2selective solvent is methanol, ethanol, N-Methyl-2-pyrrolidone (NMP), amine, propylene carbonate, dimethyl ether of polyethylene glycol (DMPEG), methyl isopropyl ether of polyethylene glycol (MPEG), tributyl phosphate, or sulfolane.

[0033] In a further embodiment, more than 50% of the energy for the drying step is recovered from the gasification of claim 1.

[0034] In an embodiment, the step of shifting CO in a portion of the sweet syngas in a water gas shift unit is replaced by the addition of green or blue hydrogen, producing a balanced syngas.

[0035] In an embodiment, the balanced syngas has a molar ratio for H2, CO and CO2noted (H2-CO2) I (CO+CO2) between 1.90 and 2.1.

[0036] In another embodiment, the balanced syngas has a molar ratio for H2, CO and CO between 2.0 and 2.05.

[0037] In a further embodiment, the balanced syngas has a molar ratio for H2, CO and CO equal to 2.03.

[0038] In another embodiment, the balanced syngas has a molar ratio adjusted for the selected production.

[0039] In an embodiment, the operating temperature of the TPTU is about 225°C to about 600°C.

[0040] In another embodiment, the carbonaceous material is converted into a slurry with a conservation of at least 80% of the carbon.

[0041] In a further embodiment, the slurry is converted into CO and CO2in the scrubbed syngas with at least 90% of carbon conversion rate.

[0042] In an embodiment, the slurry is converted into CO and CO2in the scrubbed syngas with at least 96% of carbon conversion rate.

[0043] In another embodiment, the carbonaceous material is a solid and / or a liquid containing carbon.

[0044] In a further embodiment, the carbonaceous material is a biomass.

[0045] In an embodiment, the biomass is a homogeneous biomass, a non-homogeneous biomass, a heterogeneous biomass, urban biomass, or a combination thereof.

[0046] In another embodiment, the homogeneous biomass is from a coniferous tree, a deciduous tree, an agricultural material, a primary sludge, waste cooking oil, lychee fruit bark or stillage.

[0047] In a further embodiment, the non-homogeneous biomass is from mixed forest residues, or mixed tree residues.

[0048] In an embodiment, the carbonaceous material comprises plastics, a metal, an inorganic salt, an organic compound, industrial wastes, recycling facilities rejects, automobile fluff, municipal solid waste, ICI waste, C&D waste, refuse derived fuel (RDF), solid recovered fuel, sewage sludge, used wood utility poles, wood railroad ties, wood, tire, synthetic textile, carpet, synthetic rubber, materials of fossil fuel origin, expanded polystyrene, plastic film, construction wood material, or any combination thereof.

[0049] In another embodiment, the TPTU liquid and carbonized material powder are fed independently in an entrained flow gasifier.

[0050] In a further embodiment, the TPTU liquid and carbonized material powder are fed in a gasifier using independent nozzles or using independent orifices or annuluses of the same nozzle.BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Reference will now be made to the accompanying drawings.

[0052] Fig. 1 illustrates a block diagram view of the process as described herein of producing methanol.

[0053] Fig. 2 illustrates a block diagram of the feed preparation and drying of wet carbonaceous material with heat recovery from the gasifying unit as encompassed herein.

[0054] Fig. 3 illustrates a block flow diagram of the thermal pre-treatment unit producing a slurry as described herein.

[0055] Fig. 4 illustrates a block flow diagram of the dual stage thermal pre-treatment unit producing a slurry in accordance with an embodiment.

[0056] Fig. 5 illustrates a block flow diagram of the water gas shift unit as described herein.DETAILED DESCRIPTION

[0057] In accordance with the present disclosure, there is provided method of converting a carbonaceous material into synthesis gas comprising drying a shredded carbonaceous material producing a dried material; treating the dried material in a thermal pre-treatment unit (TPTU), generating a carbonized solids stream and a TPTU liquid stream; milling the carbonized solids in a first milling step producing milled carbonized solids; removing metal and non-metal inert from the milled carbonized solids; grinding the milled carbonized solids in a second milling step, producing a carbonized material powder; mixing the TPTU liquid with the carbonized material powder, producing a slurry; gasifying the slurry in a gasifying process at a temperature above 1000°C, producing syngas.

[0058] As encompassed herein, the carbonaceous material is converted into a slurry with a conservation of at least 80%-96% of the carbon.

[0059] One aim of the present disclosure is to provide a method of converting a carbonaceous material into synthesis gas comprising drying the wet carbonaceous material in a dryer using recovered energy from the gasifying process or from an external source; thermally pre-treating the dried carbonaceous material in a thermal pre-treatmentunit “TPTU” producing a minimum of three streams, a TPTU Gas and a carbonized solids stream and a third stream of TPTU liquid; milling the carbonized solids in a first milling step, optionally removing metal and non-metal inert from the carbonized solids; grinding the carbonized solids in a second milling step to produce a carbonized material powder; optionally mixing the carbonized material powder with the TPTU liquid to produce a slurry; introducing the said carbonized material powder and TPTU liquid or slurry in a gasifying unit operating at a temperature above 1000°C producing a scrubbed syngas.

[0060] As encompassed herein, carbonaceous material refers to any gas, liquid, or combination thereof that contains the “carbon” atom. In most cases, these atoms may be originated from plants or animals and their derivatives, or from fossil fuel and its derivatives. Examples of carbonaceous materials include, but are not limited to, Municipal Solid Waste (MSW); Industrial, Commercial, and Institutional waste (IC&I); Construction and Demolition waste (C&D); any petroleum product; plastic; End of Life Tires (ELT); homogenous and / or non-homogeneous biomass.

[0061] It is provided a method of converting a carbonaceous material into synthesis gas comprising thermally pre-treating the carbonaceous material, preparing a carbonized slurry with the pre-treated material, gasifying the carbonized slurry at a temperature above 1000°C, and scrubbing the syngas to obtain a scrubbed syngas.

[0062] As encompassed herein, a “slurry” is intended to mean a liquid-solid mixture made of very fine solids having a particle diameter below 1 mm and a liquid which can be water and / or an organic liquid. The mass fraction of solids in the slurry is generally between 40 % and 70% but it can be as low as 10% and as high as 80%. One important characteristic of a slurry is its ability to flow in a pipe and to be processed in a pump, either a conventional pump or a specialized pump designed for slurries.

[0063] Contrary to coal feedstocks which have a relatively narrow range of particle density / size, biomass, waste and mixtures of both have a very broad range of particle diameter and bulk density. As can be seen from Table 2, for a same mass, the particle size of different biomass, waste and aggregate can result into a particle apparent diameter ratio ranging from about 1 up to 800 (ratio of largest particle / smallest particle). If one would sieve such a broad range of material to a specific particle size diameter, particles having the same diameter would range in mass ratio from 1 to 800 (ratio of heaviest particle / lightest particle). Feeding such a range of feedstock density into an entrained-flow gasifier creates heterogeneity in the carbon to syngas efficiency. Thus,presently entrained-flow gasifiers (or thermal reformer) can operate at high temperatures and handle melted mineral only when the particle size is small, in the micron range, and when the mass, particle size distribution, and residual mineral content is uniform.Table 2: Average typical density of different materials&

[0064] Entrained flow gasifiers can operate at pressure above 20 bar and even above 70 bar when a coal / water slurry feed system is used whereas dry coal feed systems are limited to lower pressures (below 48 bar). A dry feed system also requires inert gas injection, for example N2orC02, for the pressurization and to assist the feeding in the gasifier. The amount of gas required is a function of feed density and gasification pressure. In the gasifier, N2and / or CO2entering with the feedstock must be heated to the reforming temperature which significantly reduces the efficiency of the gasifying process. The main drawback of coal / water slurry is the impact of water on the overall gasification efficiency. Evaporation of water and heating of that vapor to > 1000°C requires a significant amount of energy which translates in increased oxygen consumption and reduced H2and CO yield. Alternatively, an organic liquid can replace a portion or all the water in a slurry. The organic liquid contributes to the syngas yield and eliminates the impact of adding water in a gasifier. For example, first coal-oil mixture (COM) technologies for combustion purposes were developed as soon as 1879 but the preparation cost and added complexity limited its uses.

[0065] It has been demonstrated that thermally treating a carbonaceous or biomass material increases its calorific value (i.e., LHV or HHV) by losing proportionally more oxygen than carbon. The mass fraction of carbon also increases with increasing treatment temperature thus increasing the carbon density of the material. The thermal pre-treatment can also greatly increase the grindability of a carbonaceous or biomass material, enabling the size reduction to below 1mm with conventional milling apparatus and reasonable power consumption.

[0066] Heat loss, fluidization steam and inert gas injection such as CO2all have a significant impact on the syngas yield (H2and CO) of a gasifying unit comprising a fluidized bed gasifier followed by a thermal reformer. Feeding an entrained flow gasifier with a carbonaceous slurry eliminates the inert gas injection and fluidization steam and the possibility to operate at much higher pressure compared to a fluidized bed gasifier significantly reduces the volume of the gasifier and thus reduces the overall heat loss.

[0067] It has also been demonstrated by the Karlsruhe Institute of Technology (KIT) that dry biomass can be pretreated at 500°C to produce what they call a “Biosyncrude” which is a mixture of pyrolysis coke (up to 40 wt%) and pyrolysis oil. This biosyncrude was then successfully converted into syngas in an entrained flow gasifier at a temperature above 1200°C.

[0068] It is thus provided a method for preparing, treating and converting a carbonaceous material into an optimized synthesis gas or sweet syngas with high carbon to syngas conversion rate, maximized production of H2and CO and minimal impurities. In orderto achieve this objective, the method comprises drying and thermally pre-treating a carbonaceous material to form a carbonized material powder and a TPTU liquid. The method comprises afterwards mixing the carbonized material powder and the TPTU liquid to form a slurry. The slurry from the TPTU is then pumped to a gasifying unit to form a scrubbed syngas. The gasifying unit comprises a high temperature gasifier, quench, heat recovery exchangers and scrubbing column. Afterwards, CO2, H2S and other contaminants are removed from the scrubbed syngas by absorption using a selective solvent, thus forming a sweet syngas (e.g. methanol, ethanol, N-Methyl-2-pyrrolidone (NMP), amine, propylene carbonate, dimethyl ether of polyethylene glycol (DMPEG), methyl isopropyl ether of polyethylene glycol (MPEG), tributyl phosphate, or sulfolane).

[0069] It is also encompassed herein purifying the scrubbed syngas in a CO2 / H2S absorption unit producing a sweet syngas; shifting the sweet syngas in a Water Gas Shift “WGS” unit or alternatively adding imported H2to produce a balanced syngas and; introducing the balanced syngas in a methanol production unit to produce high purity methanol.

[0070] In an embodiment, the balanced syngas has a molar ratio for H2, CO and CO2noted (H2-CO2) I (CO+CO2) between 1.90 and 2.1. Also encompassed is the balanced syngas having a molar ratio adjusted for the selected production.

[0071] As illustrated in Fig. 1, the carbonaceous material 001 and optionally a biomass stream 002 are introduced in a feed preparation unit 100 where they are shredded and sorted to remove metal inerts 102 such as iron, copper or aluminum and non-metallic inerts 103 such as rock, glass or ceramics. The sorted carbonaceous material 101 is introduced in a dryer 200 to reduce the moisture below 14 wt% and preferably below 10%. The dried material 201 is then introduced in a TPTU 300 where it is exposed to moderate temperature in the absence of oxygen or almost no oxygen and where chemical and physical changes occur (i.e. the operating temperature of the TPTU is about 225°C to about 600°C). The products of the TPTU are a slurry 301 comprising a solid and a liquid fraction and a waste gas 319. The waste gas 319 is combusted in a gas burner and the heat is recovered from the hot flue gas 320. The cold flue gas 322 is then treated in a gas treatment unit to remove contaminants before its release to atmosphere. The slurry 301 is introduced in the gasifying unit 400 where it is converted to a scrubbed syngas 401 mainly composed of H2, CO, CO2and other compounds in small concentration. The scrubbed syngas 401 is then introduced in a H2S & CO2absorption unit 500 where it is purified to produce a sweet syngas 501 for further use as fuel, power generation, alcohol synthesis (MeOH, DME, EtOH and others), hydrocarbon synthesis and other uses. The H2S and CO2absorption unit also produces a residual gas 505 containing mainly CO2and H2S. Fig. 1 illustrates an embodiment including methanol synthesis and, the stoichiometry of the sweet syngas (H2vs CO and CO2) must be adjusted as it is the case for other chemical synthesis. To adjust the stoichiometry, a portion of the sweet syngas 501 is introduced in a WGS unit where CO is converted to CO2over a catalyst in the presence of steam to produce H2and where the produced CO2is removed by absorption with a selective solvent. The gas leaving the WGS unit is mixed with the un-shifted portion of the sweet syngas 501 to form a balanced syngas 601 which is introduced in a methanol synthesis 700 to produce high purity methanol 701. The methanol synthesis unit 700 comprises a methanol reaction loop operating at highpressure and distillation columns operating near atmospheric pressure or below atmospheric pressure or both to remove water 703 and contaminants. The liquid contaminants 702 are recycled with waste liquid 504 from the CO2 / H2S Absorption unit 500 to the gasifying unit 400 where they are converted back to syngas.

[0072] In an embodiment, the process described herein encompasses shifting CO in a portion of the sweet syngas in a water gas shift unit, removing produced CO2in a CO2absorption unit and mixing with the un-shifted portion of the sweet syngas, producing a balanced syngas and; converting said balanced syngas into methanol in a methanol reactor

[0073] also encompassed is the formation of other products from syngas as described herein, such as for example, Fischer-Tropsch fuel, Fischer-Tropsch to Olefins (FTO) synthesis.

[0074] In an embodiment, the carbonaceous material and biomass stream are shredded to a size below 50-100 cm.

[0075] In an embodiment, a portion or all of the heat for the dryer is provided from process recovered heat which is transferred with a transfer fluid 410 and 411. The heat can also be recovered from the TPTU 300. In another embodiment, the temperature of the TPTU is between 300°C and 600°C.

[0076] In an embodiment, the gasifying unit comprises an entrained flow gasifier operating at a temperature above 1000°C, a quench, heat recovery exchangers and a water scrubber. In another embodiment, the entrained flow gasifier is preceded by a fluidized bed gasifier operating at a temperature below 1000°C. In another embodiment, the TPTU liquid 337 and baked solids 316 or cooled carbonized solids 327 are fed directly in a fluidized bed gasifier followed by a thermal reformer.

[0077] As illustrated in Fig. 2, the carbonaceous material 001 and biomass stream 002 are treated in separate conditioning lines 106 and 107 where they are shredded and sorted. The sorted carbonaceous material 104 and sorted biomass 105 are stored in a wet storage 108. The sorted material is then introduced in the feed dryer 206 which uses hot air 204 to remove moisture from the material in the dryer. The air 203 is heated in heat exchangers 208 and the heat is provided by a heat transfer fluid 410. A short term storage 207 provides a buffer capacity and it is fed with the dried material 202 from thedryer 206. The hot humid air 205 and the dried material 201 are leaving the drying unit 200 with a moisture content preferably below 14 wt% and most preferably below 10 wt%.

[0078] In an embodiment, the carbonaceous material 001 and biomass stream 002 are shredded and / or sorted in the same conditioning line 106.

[0079] As illustrated in Fig. 3, the dried material 201 is introduced in a feeding device 302 that minimizes the amount of air entering the thermal pre-treatment reactor 305. The feeding device also prevents gas from leaving the thermal pre-treatment reactor. The dried material is exposed to a temperature between 300 and 600°C inside the thermal pre-treatment reactor. In this temperature range, the dried material undergoes physical and chemical changes which produces two streams, a TPTU Gas 324 and carbonized solids 326. The TPTU gas leaves the TPTU reactor and, in an option illustrated in Fig. 3, it is divided into two fractions. The first TPTU gas fraction is heated in a heat recovery exchanger 315 with the hot TPTU flue gas 320 from the TPTU burner 312. This heated TPTU gas 317 is recirculated in the TPTU reactor 305 to provide heat for the thermal pre-treatment. The second TPTU gas fraction is vented by pressure control to a condenser 314 where the water and organic compounds will condense in the cooled TPTU gas 318. The cooled TPTU gas is introduced in a separator 311 which separates the TPTU liquid 337 from the waste gas 319. The gas leaving the separator is burnt in the TPTU burner, producing the hot TPTU flue gas. The cooled TPTU flue gas 334 leaving the heat recovery exchanger 315 is treated in a flue gas treatment unit 313, producing a clean flue gas 333 which complies with applicable regulations. In an alternative option (dashed lines), the TPTU Gas 324 is not divided into two fractions and 100% of the stream is cooled in the condenser 314. The waste gas 319 is burnt in the TPTU burner 312 and the hot TPTU flue gas 320 is providing heat indirectly to the TPTU reactor 305. The cooled TPTU flue gas 322 leaving the TPTU reactor 305 flue is treated in the flue gas treatment unit 313 similar to the previous option. On the solid side, the carbonized solids 326 fall into a cooling apparatus 306 to reduce the temperature below 150°C. The cooled carbonized solids 327 may be more or less agglomerated depending on the composition of the dried material 201 and the operating temperature of the TPTU. The cooled carbonized solids 327 are then introduced in a first milling apparatus 307, producing milled carbonized solids 328 with a particle size of 10 mm or less. The milled carbonized solids 328 are sorted in a second sorting apparatus 308 removing metal 331 and non-metal inert 332. The thermal pre-treatment combined with the milling below 10 mm can enable the sorting of metal and non-metal inert that are not accessible (e.g., imbedded in plastic) in the feed preparation unit. To produce a powder, the sorted milledcarbonized solids 329 are introduced in a second milling apparatus, producing a carbonized powder 330 with a particle size of 1 mm or less. The carbonized powder 330 and the TPTU liquid 337 are mixed in a slurry preparation apparatus 310, producing a carbonaceous slurry or slurry 301.

[0080] The TPTU can be divided into two separate stages operating at two different temperatures. The objective of the first stage is to volatilize most of the H2O that is generated in the TPTU and to send this vapor directly to the burner. This staging also gives the opportunity to remove a fine and brittle solid fraction before the second stage of the TPTU thus minimizing the carbon loss of that fraction and increasing the overall carbon recovery in the TPTU Products. As illustrated in Fig. 4, the dried material 201 is introduced in a feeding device 302 that minimizes the amount of air entering the thermal pre-treatment reactors 303 and 305. The feeding device also prevents gas from leaving the thermal pre-treatment reactors. The dried material then falls in the first TPTU reactor 303 where it is exposed to a temperature between 200 and 400°C. In this temperature range, the dried material undergoes physical and chemical changes which produces two streams, the first stage TPTU Gas 325 and baked solids 316. The first stage TPTU gas 325 goes directly to the TPTU burner as it contains most of the water evaporated or generated in the TPTU reactors. The baked solids 316 are transferred to the second TPTU reactor 305 where they are exposed to a temperature between 300 and 600°C. In this higher temperature range, the baked solids undergo more physical and chemical changes which again produces two streams, the second stage TPTU Gas 324 and carbonized solids 326. The second stage TPTU gas 324 leaves the second TPTU reactor and, in an option illustrated in Fig. 4, it is divided into two fractions. The first TPTU gas fraction is heated in a heat recovery exchanger 315 with the hot TPTU flue gas 320 from the TPTU burner 312. This heated TPTU gas 317 is recirculated in the second TPTU reactor 305 to provide heat for the second stage of the thermal pre-treatment. The second TPTU gas fraction is vented by pressure control to a condenser 314 where the water and organic compounds will condense in the cooled TPTU Gas 318. The cooled TPTU gas is introduced in a separator 311 which separates the TPTU liquid 337 from the waste gas 319. The gas leaving the separator is also burnt in the TPTU burner, producing the hot TPTU flue gas 320. The medium temperature TPTU flue gas 321 leaving the heat recovery exchanger 315 still contains enough energy to heat, at least partially, the first TPTU reactor 303. The cooled TPTU flue gas 322 leaving the first TPTU reactor 303 is treated in a flue gas treatment unit 313, producing a clean flue gas 333 which complies with applicable regulations. On the solid side, the carbonized solids 326fall into a cooling apparatus 306 to reduce the temperature below 150°C. The cooled carbonized solids 327 may be more or less agglomerated depending on the composition of the dried material 201 and the operating temperature of the TPTU. The cooled carbonized solids 327 are then introduced in a first milling apparatus 307, producing milled carbonized solids 328 with a particle size of 10 mm or less. The milled carbonized solids 328 are sorted in a second sorting apparatus 308 removing metal 331 and non-metal inert 332. To produce a powder, the sorted milled carbonized solids 329 are introduced in a second milling apparatus, producing a carbonized powder 330 with a particle size of 1 mm or less. The carbonized powder 330 and the TPTU liquid 337 are mixed in a slurry preparation apparatus 310, producing a carbonaceous slurry or slurry 301. Optionally, a classifier 304 (e.g. using an aerodynamic classifier) can be utilized to separate a fine and brittle fraction 323 from the baked solids 316. This brittle fraction is then introduced in the feed of the second milling apparatus 309 to produce the carbonized powder 330.

[0081] In an embodiment, the first TPTU reactor 303 and / or TPTU reactor 305 is / are heated with a heat transfer fluid such as thermal fluid or molten salts which is heated with recovered heat from the TPTU unit 300 and / or from and external heat source. In another embodiment, the TPTU reactor(s) are heated with electricity directly or indirectly, for example by resistive heating, induction heating or plasma arc.

[0082] In an embodiment, the cooling device 306 also includes a discharge device which, similarly to the feeding device 302, minimizes air leaks inside the thermal pretreatment reactor 305 as well as gas leaks outside of the thermal pre-treatment reactor.

[0083] In an embodiment, the cooling device 306 uses water injection to reduce the temperature of the carbon-densified solids by evaporation. In this case, the generated water vapor circulates back in the thermal pre-treatment reactor and mixes with the TPTU gas leaving the reactor. In another embodiment, the water vapor is condensed in a dedicated exchanger to avoid mixing with the TPTU gas.

[0084] In an embodiment, the condenser 314 and separator 311 are a direct contact cooler apparatus. Accordingly, it is encompassed that the condenser is a direct contact heat exchanger or an indirect heat exchanger. In this case, the second TPTU Gas fraction 318 enters a column where a cooled fluid is sprayed to cool the gas and to condense water and organic compounds. Most of the liquid leaving the column is cooled and recirculated to the column to cool the TPTU Gas. The excess liquid is removed fromthe direct contact cooler apparatus by level control and represents the TPTU liquid 337 while the gas leaving the column represents the waste gas 319.

[0085] In an embodiment, the temperature of the condenser 314 is adjusted to allow more or less organic compounds in the waste gas 319 which can generate more or less heat in the TPTU burner 312.

[0086] In an embodiment, the cooled TPTU flue gas 334 or 322 is treated in the flue gas treatment unit of a gasifying process.

[0087] In an embodiment, air 335 and natural gas 336 or another combustible gas or liquid are added in the TPTU burner 312 to stabilize the operation or to provide additional heat.

[0088] In the example of methanol production illustrated in Fig. 1 it is necessary to adjust the stoichiometry of the syngas entering the methanol synthesis unit. Blue or green hydrogen 710 can be added in the syngas to get the preferred ratio of H2over CO and CO2(SN = 2.03). When green or blue hydrogen is not available, a WGS unit is generally used to produce more hydrogen from the reaction of CO with H2O (reaction 1). As illustrated in Fig. 5, the sweet syngas 501 is separated into two fractions in the WGS unit 600. The first syngas fraction 502 is heated in the WGS feed effluent exchanger 610 and Steam 606 is added to the heated syngas fraction 607. The mixture of steam and syngas is introduced in the WGS reactor 604 where the reaction occurs. The product from the WGS reactor is a hot shifted syngas 609 with more hydrogen, less CO, more CO2and un-reacted H2O. The energy in the hot shifted syngas 609 is recovered in the WGS feed / effluent exchanger 610 after which the gas is cooled in a condenser 615, generally using water or air as a utility fluid. As provided herewith, more than 50% of the energy for the drying in step is recovered from the gasification. The shifted syngas is further cooled in a second feed / effluent exchanger 616 to condense the un-reacted H2O. A cooled shifted syngas 611 is then introduced in a CO2absorption unit 605 producing a cold H2rich syngas 612 and where CO2603 and H2O 614 are extracted in separate streams. The CO2absorption unit may also produce a low pressure H2rich gas 613 that is recycled upstream of the H2S and CO2absorption unit 500. The second syngas fraction 503 is mixed with the cold H2rich syngas 612 before the second feed / effluent exchanger 616 where the gas is heated. At this point, the resulting syngas is a balanced syngas 601, also called makeup gas, with the preferred stoichiometry for the production of Methanol.CO + H2O CO2+ H2(1)

[0089] It is further encompassed the formation of other products from syngas as described herein, such as for example, Fischer-Tropsch fuel, Fischer-Tropsch to Olefins (FTO) synthesis

[0090] Accordingly, the method of converting a carbonaceous material into synthesis gas as provided herewith reduces variability in physical and chemical properties of the feedstock. The thermally treated material can be fed directly in an EFG, and avoids cofeeding with a fossil fuel (e.g., Coal or liquid hydrocarbon). The method encompassed herein allows increase in reliability of the gasification process. Any “black swan event” will happen at the pre-treatment stage, (e.g., large rock) and the pre-treatment will enable the removal of imbedded inert material (e.g., insulated metal wire) before the gasification step. It increases the overall gasification efficiency when compared to direct gasification of waste or biomass. This is true when the pre-treatment conditions are not too severe to avoid losing too much material in the off-gas stream of the TPTU.

[0091] The greenhouse gas (GHG) reduction of the overall process (waste to syngas) has been demonstrated as:-more H2+CO production (conversion) per ton of feedstock;-less electricity needed;-less O2input to the gasifying process; and-less H2import needed when it is the selected line-up.

[0092] The method provided herewith allows the enrichment of biogenic carbon in the powder stream and the enrichment of fossil carbon in the solid stream. It further reduces the carbon loss in the TPTU when only a fraction of the material goes in the second TPTU stage and increases the amount of slurry. The amount of material going in the second stage could be adjusted to optimize and adjust the amount of liquid for the production of the slurry.

[0093] It is encompassed that the thermal pre-treatment may require multiple units to reach the required capacity. Those units should preferably be identical unless they operate in series, at different temperatures (staged thermal pre-treatment). The operation in series allows to extract a portion of the material after the first stage and the addition of a crushing and / or classification step provides a means to separate a bio-rich fraction which will be more brittle and porous after the first stage. The classification of powder vs solid (i.e., chunks) can be done mechanically or aerodynamically. Additionally, the staged TPT can reduce the carbon lost in the gas phase, thus increasing the amount of material going to the gasification.

[0094] A slurry can be fed into a bubbling bed gasifier with a pump, removing complex feeding equipment and inert gas associated with the feeding of solids. The increased gasification efficiency will compensate for the carbon loss occurring during the pre-treatment. Also, it will be easier to increase the pressure of the gasification, reducing the syngas compression downstream of the gasifier.

[0095] Additionally, the thermally treated material can be grinded to generate as much powder as possible. The grinding will accelerate the gasification process and the powder <0.5 mm will be quickly entrained in the reformer, reducing the amount of material in the fluidized bed of the gasifier. This has the potential to reduce the size of the gasifier, and the steam required for fluidization. Also, the powder fraction and the coarse fraction could be fed separately in the gasifier, in order to promote the entrainment of the powder in the freeboard.

[0096] In the Thermal pre-Treatment Unit, some contaminantswill be released in the gas stream. For example, PVC releases chlorine mainly between 240 and 350°C, mostly in the form of HCI. The solid and liquid streams leaving the TPTU will contain significantly less Chlorine than the dried RDF entering the TPTU. The material of construction for the scrubbing loop downstream of the reformer is affected by the amounts of halogens (mainly Cl) present in the feed of the gasifier. If the amount of contaminants entering the gasification is lower for any reason, it will be possible to change the material of construction for a cheaper I less corrosion resistant material. Additionally, a hot removal step for HCI can be included in the TPTU on the gas stream before condensing the oil to minimize the amount of Cl in the liquid stream. The removal efficiency can also be positively affected by higher temperatures. In any case, the flue gas of the TPTU will have to meet the atmospheric release limits. Inert material (e.g., rock and metals) retrieved in the TPTU can be stripped with steam to remove leachable contaminants.

[0097] While the description has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations and including such departures from the present disclosure as come within known or customary practice within the art and as may be applied to the essential features hereinbefore set forth, and as follows in the scope of the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A method of converting a carbonaceous material into an optimized synthesis gas comprising:a) optionally drying a shredded carbonaceous material producing a dried material; b) treating said dried material or shredded carbonaceous material at a temperature above 300°C in a thermal pre-treatment unit (TPTU), generating a carbonized solids stream, a waste gas and a TPTU liquid stream;c) milling the carbonized solids in a first milling step producing milled carbonized solids or carbonized material powder;d) mixing the TPTU liquid with the carbonized material powder, producing a slurry; e) gasifying the slurry in a gasifying process at a temperature above 1000°C, producing a scrubbed syngas, and solid residues; andf) removing CO2and H2S from the scrubbed syngas producing the optimized synthesis gas or sweet syngas.

2. The method of claim 1 , further comprising the step of:c’) removing metal and non-metal inert from said milled carbonized solids and; c”) grinding the milled carbonized solids in a second milling step, producing the carbonized material powder.

3. The method of claim 1, further comprising the step a’) of treating said dried material in a primary TPTU reactor, creating a first stage TPTU gas stream in addition to a baked solids stream.

4. The method of any one of claims 1-3, further comprising the steps ofg) shifting CO in a portion of the sweet syngas in a water gas shift unit, removing produced CO2in a CO2absorption unit and mixing with the un-shifted portion of the sweet syngas, producing a balanced syngas and;h) converting said balanced syngas into methanol in a methanol reactor.

5. The method of claim 3, wherein the baked solids generated in step a’) are classified, creating a fine and brittle fraction.

6. The method of claim 5, wherein the baked solids are classified in an aerodynamic classifier.

7. The method of claim 5 or 6, wherein the fine and brittle fraction is introduced with the carbonized solids in the milling step c) or with the milled carbonized solids in the second milling step c”).

8. The method of any one of claims 1-7, wherein the TPTU comprises a condenser to condense the TPTU liquid.

9. The method of claim 8, wherein the condenser is a direct contact heat exchanger or an indirect heat exchanger.

10. The method of any one of claims 1 -3, wherein the first stage TPTU gas and / or waste gas are burnt producing heat which is recovered in an exchanger or indirectly in the TPTU reactor and / or primary TPTU reactor.

11. The method of claim 4, wherein in step h), where the balanced syngas is converted into Fischer-Tropsch products, ethanol, synthetic or substitute natural gas.

12. The method of claim 10, wherein the heat is used for the TPTU.

13. The method of any one of claims 1-12, wherein the carbonized solids are milled to a particle size of 10 mm and less.

14. The method of any one of claims 1-13, wherein the milled carbonized solids are ground to a particle size of 1 mm and less.

15. The method of any one of claims 1-14, wherein the slurry is gasified in an entrained flow gasifier followed by a quench, heat recovery exchangers and a water scrubber.

16. The method of claim 15, wherein the entrained flow gasifier is preceded by a fluidized bed gasifier operating at a temperature below 1000°C.

17. The method of any one of claims 1-16, wherein the baked solids and / or carbonized solids and the TPTU liquid are fed directly in a fluidized bed gasifier followed by a thermal reformer.

18. The method of any one of claim 1-17, wherein the CO2and H2S are removed from the syngas by absorption using a CO2selective solvent.

19. The process of claim 18, wherein the CO2selective solvent is methanol, ethanol, N-Methyl-2-pyrrolidone (NMP), amine, propylene carbonate, dimethyl ether of polyethylene glycol (DMPEG), methyl isopropyl ether of polyethylene glycol (MPEG), tributyl phosphate, or sulfolane.

20. The method of any one of claims 1-19, wherein more than 50% of the energy for the drying in step a) is recovered from the gasification, step e) of claim 1.

21. The method of claim 4, wherein step g) is replaced by the addition of green or blue hydrogen, producing a balanced syngas.

22. The method of claim 4, wherein the balanced syngas has a molar ratio for H2, CO and CO2noted (H2-CO2) I (CO+CO2) between 1.90 and 2.1.

23. The method of claim 4 or 22, wherein the balanced syngas has a molar ratio for H2, CO and CO between 2.0 and 2.05.

24. The method of any one of claims 4, 22 and 23, wherein the balanced syngas has a molar ratio for H2, CO and CO equal to 2.03.

25. The method of claim 11 , wherein the balanced syngas has a molar ratio adjusted for the selected production.

26. The method of any one of claims 1-25, wherein the operating temperature of the TPTU is about 225°C to about 600°C.

27. The method of any one of claims 1-26, wherein the carbonaceous material is converted into a slurry with a conservation of at least 80% of the carbon.

28. The method of any one of claims 1-27, wherein the slurry is converted into CO and CO2in the scrubbed syngas with at least 90% of carbon conversion rate.

29. The method of any one of claims 1-28, wherein the slurry is converted into CO and CO2in the scrubbed syngas with at least 96% of carbon conversion rate.

30. The method of any one of claims 1-29, wherein the carbonaceous material is a solid and / or a liquid containing carbon.

31. The method of any one of claims 1-30, wherein the carbonaceous material is a biomass.

32. The method of claim 31, wherein the biomass is a homogeneous biomass, a non-homogeneous biomass, a heterogeneous biomass, urban biomass, or a combination thereof.

33. The method of claim 32, wherein the homogeneous biomass is from a coniferous tree, a deciduous tree, an agricultural material, a primary sludge, waste cooking oil, lychee fruit bark or stillage.

34. The method of claim 33, wherein the non-homogeneous biomass is from mixed forest residues, or mixed tree residues.

35. The method of any one of claims 1 -32, wherein the carbonaceous material comprises plastics, a metal, an inorganic salt, an organic compound, industrial wastes, recycling facilities rejects, automobile fluff, municipal solid waste, ICI waste, C&D waste, refuse derived fuel (RDF), solid recovered fuel, sewage sludge, used wood utility poles, wood railroad ties, wood, tire, synthetic textile, carpet, synthetic rubber, materials of fossil fuel origin, expanded polystyrene, plastic film, construction wood material, or any combination thereof.

36. The method of any one of claims 1-14, wherein the TPU liquid and carbonized material powder are fed independently in an entrained flow gasifier.

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