Pyrolytic cracking of sugars

Abstract

The present invention relates to a process for the pyrolysis cracking of sugars to C1-C3 oxygenates, the process comprising cooling the cracked product downstream of the reactor to a cooling temperature of 230 DEG C to 390 DEG C and then separating solids from the cracked product cooled to the cooling temperature. The invention also relates to a system for performing the pyrolysis cracking of sugars into C1-C3 oxygenates. The method and system are suitable for industrial scale production.

Description

Technical Field

[0001] The present invention relates to a method for thermally cracking sugar into C1-C3 oxygen-containing compounds. The present invention also relates to a system for thermally cracking sugar into C1-C3 oxygen-containing compounds. The method and system are suitable for industrial-scale production. Background Art

[0002] Biomass is particularly attractive as a raw material because of its potential to supplement or even replace petroleum as a feedstock for the preparation of commercial chemicals. In recent years, various technologies for utilizing biomass have been investigated. Carbohydrates constitute a large part of biomass, and various strategies are being established to efficiently utilize them as feedstocks for the preparation of commercial chemicals. These strategies include various fermentation-based methods, pyrolysis, and different approaches using catalysis, such as hydrogenolysis, conversion via retroaldehyde chemistry, and various acid-catalyzed dehydration methods.

[0003] Examples of chemicals produced from biomass include: small alcohols such as ethanol, propanol, and butanol; monomers such as ethylene glycol, ethylene, propylene, butadiene, isoprene, furandicarboxylic acid, succinic acid, lactic acid and lactide, acrylic acid, epichlorohydrin, and vinyl glycolic acid. Also included are diols such as 1,2-propylene glycol, 1,2-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,2-hexanediol, and sorbitol, glycerol, glycolaldehyde, methylglyoxal, and levulinic acid. Other products such as alternative natural gas, syngas, and biofuels are also included.

[0004] In the field of pyrolysis, there has been a lot of effort to produce the above-mentioned chemicals using solid biomass-based feedstocks and other lignocellulosic materials.

[0005] Some efforts have been made to use sugars as raw materials for producing food browning materials, with large amounts of glycolaldehyde (also known as hydroxyacetaldehyde) acting as the key browning agent.

[0006] Fluidized bed reactors containing heat-carrying particles are used to process a variety of feedstocks. They can be operated in many different fluidization schemes. The preferred scheme is selected depending on the feedstock in question and the desired chemical to be obtained, which results in a large number of different reactor configurations for fluidized bed reactors.

[0007] For the conversion of biomass to bio-oil by pyrolysis, several reactor configurations have been investigated, such as dense phase (i.e., bubbling fluidized bed) and dilute phase (i.e., riser) reactors, as well as completely different reactor types, such as ablative pyrolysis reactors.

[0008] Examples of prior art disclosing the use of fluidized bed reactors include US 5,397,582 (Underwood), US 7,094,932 (Majerski), WO 2014 / 131764, WO 2012 / 115754, US 5,302,280 (Lomas) and WO 2017 / 216311 (Larsen et al.).

[0009] There remains a need for improved methods and systems for the pyrolytic cracking of sugars into C1-C3 oxygenates, particularly methods and systems suitable for industrial-scale production. Summary of the invention

[0010] According to one aspect of the present invention, there is provided a method for thermally cracking sugar into C1-C3 oxygen-containing compounds, the method comprising the following steps:

[0011] a) providing an aqueous raw material solution containing sugar;

[0012] b) providing a fluidized bed pyrolysis reactor for pyrolyzing and cracking sugar, wherein the fluidized bed pyrolysis reactor contains fluidizable heat-carrying particles;

[0013] c) introducing the feedstock solution into a reactor to pyrolyze and crack the sugar to provide a cracked product comprising C1-C3 oxygen-containing compounds, wherein the temperature of the cracked product at the reactor outlet is at least 400° C.;

[0014] d) cooling the cracked products downstream of the reactor to a cooling temperature of 230° C. to 390° C.; and

[0015] e) separating solids from the cracked products cooled to the cooling temperature, wherein the solids include solids selected from the group consisting of fluidizable heat-carrying particles, fragments of fluidizable heat-carrying particles, by-products from pyrolytic cracking of the feed solution, and mixtures thereof.

[0016] The inventors are surprised to find that by cooling the cracked products downstream of the reactor to a cooling temperature, the method can achieve a good yield of C1-C3 oxygenates while improving efficiency and improving design. In particular, by a downstream cooling step, for example, the physical unit operations of the cooling step and the reactor can be arranged at different positions from each other, rather than including the cooling step in the reactor. In this way, the design of the reactor does not need to adapt to the physical unit operations of the cooling step, thereby reducing design complexity and installation complexity, and improving space efficiency and ease of handling. In terms of reducing installation complexity, the physical unit operations of the cooling step can be located at a position closer to the ground than the reactor and installed independently of the reactor. In terms of space efficiency and ease of operation, since the design of the reactor does not need to accommodate the physical unit operations of the cooling step, the reactor can be more compact and lighter in weight. In addition, for example, once the reactor is installed, the physical unit operations of the cooling step can be connected to the reactor (for example, in a modular manner). Cooling the reactor downstream to a cooling temperature unexpectedly brings these advantages and also brings a good yield of C1-C3 oxygenates.

[0017] The above advantages are particularly beneficial in the context of industrial production equipment, where large amounts of capital expenditures (CAPEX) and operating expenditures (OPEX) can be spent on building and maintaining process equipment, and where product yield is a major consideration.

[0018] As used herein, the terms "downstream" and "upstream" are relative to the direction of component flow. For example, the outlet of a reactor is located downstream of the point where the feed solution is introduced into the reactor, assuming that the components flow from the point where the feed solution is introduced to the outlet of the reactor.

[0019] a) Raw material solution

[0020] The method includes providing an aqueous raw material solution containing a sugar.

[0021] In one aspect, the total content of sugars in the feed solution is at least 30 wt.%, e.g., at least 35 wt.%, at least 40 wt.%, at least 45 wt.%, at least 50 wt.%, at least 55 wt.%, at least 60 wt.%, at least 65 wt.%, at least 70 wt.%, at least 75 wt.%, at least 80 wt.%, at least 85 wt.%, at least 90 wt.%, or at least 95 wt.%, based on the total weight of the feed solution.

[0022] In one aspect, the total content of sugars in the feed solution is no greater than 99.9 wt.%, e.g., no greater than 99.5 wt.%, no greater than 99 wt.%, no greater than 95 wt.%, no greater than 85 wt.%, or no greater than 80 wt.%, based on the total weight of the feed solution.

[0023] In one aspect, the total content of sugars in the feed solution is 30 to 99 wt.%, such as 40 to 90 wt.%, or 50 to 80 wt.%, based on the total weight of the feed solution.

[0024] In one aspect, the feedstock solution is a liquid.

[0025] In one aspect, the water content of the feed solution is at least 20 wt.%, e.g., at least 25 wt.%, at least 30 wt.%, at least 35 wt.%, at least 40 wt.%, at least 45 wt.%, at least 50 wt.%, based on the total weight of the feed solution.

[0026] In one aspect, the water content of the feedstock solution is no greater than 70 wt.%, e.g., no greater than 65 wt.%, no greater than 60 wt.%, no greater than 55 wt.%, no greater than 50 wt.%, or no greater than 45 wt.%, based on the total weight of the feedstock solution.

[0027] In one aspect, the total content of sugars in the aqueous feed solution is 20 to 70 wt.%, eg, 25 to 60 wt.%, or 30 to 50 wt.%, based on the total weight of the feed solution.

[0028] In one aspect, the sugar is a carbohydrate comprising one or more C6 sugar units and / or C5 sugar units.

[0029] In one aspect, the sugar is a monosaccharide or a disaccharide.

[0030] In one aspect, the sugar is selected from sucrose, lactose, xylose, arabinose, ribose, mannose, tagatose, galactose, glucose and fructose.

[0031] In one aspect, the feedstock solution can comprise a syrup.

[0032] In one aspect, the feedstock solution comprises more than one sugar.

[0033] Each sugar may independently be as described herein.

[0034] b) providing a fluidized bed cracking reactor for thermal cracking of sugar, wherein the fluidized bed cracking reactor comprises fluidizable heat-carrying particles

[0035] The method includes providing a fluidized bed cracking reactor for pyrolytic cracking of sugars, wherein the fluidized bed cracking reactor contains fluidizable heat-carrying particles.

[0036] As will be appreciated by those skilled in the art, a fluidized bed reactor is a reactor that contains a bed of particles that may be fluidized, for example, by a fluidizing gas that may be introduced at the bottom of the reactor. The velocity and physical properties of the fluidizing gas combined with the physical properties of the fluidizable particles may regulate the fluidization state of the fluidizable particles in the bed. The superficial velocity of the fluidizing gas in a dense bed / turbulent bed / bubbling bed in a reactor is 0.01 to 2 m / s. The superficial velocity of the fluidizing gas in a fast bed (also referred to as a riser / transport reactor) in a reactor may be 3 to 22 m / s. However, the exact velocity range depends on the physical properties of the fluidizable particles and the fluidizing gas, and may be determined experimentally or calculated by a skilled technician.

[0037] In one aspect, the fluidized bed cracking reactor is operated in the following fluidization regimes: bubbling fluidization regime, plug flow fluidization regime, turbulent fluidization regime, fast fluidization regime, and / or pneumatic conveying regime.

[0038] In one aspect, the fluidized bed cracking reactor is operated in a fast fluidized state. Such a reactor is also referred to as a "riser reactor". Thus, in one aspect, the reactor is a riser reactor.

[0039] In one aspect, the reactor comprises a riser.

[0040] In one aspect, the riser extends vertically.

[0041] In one aspect, the riser (eg, the lower portion of the riser) includes a fluidizing gas inlet.

[0042] In one aspect, the riser (eg, the lower portion of the riser) includes a fluidizable particle inlet.

[0043] In one aspect, the riser (eg, the lower portion of the riser) includes a feedstock inlet.

[0044] In one aspect, the fluidizable particles inlet is disposed downstream of the fluidizing gas inlet.

[0045] In one aspect, the feedstock solution inlet is disposed downstream of the fluidizable particles inlet.

[0046] In one aspect, the fluidizable heat-carrying particles form a dense fluidized bed in the region between the fluidizable particles inlet and the feedstock solution inlet.

[0047] In one aspect, the riser (eg, the lower portion of the riser) comprises fluidizable particles and fluidizing gas inlets. In this way, fluidizable heat-carrying particles and fluidizing gas can be introduced into the reactor via a common inlet, eg, sequentially or simultaneously.

[0048] In one aspect, the feedstock solution inlet is disposed downstream of the fluidizable particles and the fluidizing gas inlet.

[0049] In one aspect, the method includes introducing fluidizable heat-carrying particles into a reactor.

[0050] In one aspect, the method includes introducing fluidizable heat carrier particles into a reactor via a fluidizable particle inlet.

[0051] In one aspect, the method includes introducing fluidizable heat-carrying particles into a reactor via fluidizable particle and fluidizing gas inlets.

[0052] In one aspect, the temperature of the fluidizable heat-carrying particles within the reactor is at least 400°C, such as at least 450°C, at least 500°C, at least 550°C, at least 600°C, or at least 650°C.

[0053] In one aspect, the temperature of the fluidizable heat-carrying particles within the reactor is no greater than 800°C, such as no greater than 700°C, or no greater than 650°C.

[0054] In one aspect, the temperature of the fluidizable heat-carrying particles within the reactor is from 400 to 800 °C, such as from 500 to 800 °C, from 450 to 650 °C, or from 550 to 650 °C.

[0055] In one aspect, the temperature of the fluidizable heat-carrying particles at the fluidizable particle inlet (or the fluidizable particle and fluidizing gas inlet) is at least 400°C, e.g., at least 450°C, at least 500°C, at least 550°C, at least 600°C, or at least 650°C.

[0056] In one aspect, the temperature of the fluidizable heat-carrying particles at the fluidizable particle inlet (or fluidizable particle and fluidizing gas inlet) is no greater than 800°C, such as no greater than 700°C, or no greater than 650°C.

[0057] In one aspect, the temperature of the fluidizable heat-carrying particles at the fluidizable particle inlet (or fluidizable particle and fluidizing gas inlet) is 400 to 800°C, such as 500 to 800°C, 450 to 650°C, or 550 to 650°C.

[0058] In one aspect, the pressure at the reactor outlet is at least 0.9 bara, e.g., at least 1 bara, at least 1.2 bara, at least 1.4 bara, at least 1.6 bara, at least 1.7 bara, at least 1.8 bara, at least 2 bara, or at least 2.2 bara.

[0059] In one aspect, the pressure at the reactor outlet is no greater than 8 bara, e.g., no greater than 6 bara, no greater than 5 bara, no greater than 4 bara, no greater than 3.5 bara, no greater than 3 bara, no greater than 2.9 bara, or no greater than 2.8 bara.

[0060] In one aspect, the pressure at the reactor outlet is 0.9 to 8 bara, e.g., 1 to 6 bara, 1.1 to 5 bara, 1.2 to 4 bara, 1.5 to 3 bara, 1.6 to 2.9 bara, 1.7 to 2.8 bara, 1.8 to 2.8 bara, 2 to 2.8 bara, or 2.2 to 2.8 bara.

[0061] In one aspect, the fluidizable heat carrying particles are selected from the group consisting of sand, mullite, silica, glass, alumina, silica-alumina, steel, and silicon carbide.

[0062] In one aspect, the average particle size of the fluidizable heat-carrying particles is 20 to 400 μm, for example 20 to 300 μm, or 20 to 200 μm. The particle size distribution can be measured by laser diffraction spectroscopy, microscopy, electrical area sensing. The average particle size can then be calculated based on the particle size distribution. The average particle size may be a Sauter average particle size. Those skilled in the art will appreciate that other average particle sizes are conceivable.

[0063] As will be appreciated by those skilled in the art, the flow of the fluidizable heat-carrying particles within the reactor may be adjusted relative to the flow of the feed solution in order to provide the desired heat to the feed solution. Fluidizable particles with a high heat capacity may require a lower mass flow rate than fluidizable particles with a lower heat capacity.

[0064] c) introducing the feed solution into a reactor to thermally crack the sugar to provide a cracked product comprising C1-C3 oxygen-containing compounds, wherein the temperature of the cracked product at the reactor outlet is at least 400° C.

[0065] The method comprises introducing a feedstock solution into a reactor to pyrolytically crack sugars to provide cracked products comprising C1-C3 oxygen-containing compounds, wherein the temperature of the cracked products at the reactor outlet is at least 400°C.

[0066] The pyrolytic cracking of sugars is an endothermic reaction, mainly due to the evaporation of any liquid in the feed solution and the reaction enthalpy of the pyrolytic cracking of sugars into oxygenated compounds.

[0067] In one aspect, the temperature of the cracked products at the reactor outlet is at least 420°C, such as at least 430°C, at least 440°C, at least 450°C, at least 460°C, or at least 470°C.

[0068] In one aspect, the temperature of the cracked products at the reactor outlet is no greater than 550°C, such as no greater than 530°C, no greater than 520°C, no greater than 510°C, no greater than 500°C, or no greater than 490°C.

[0069] In one aspect, the temperature of the cracked products at the reactor outlet is 400 to 600°C, eg, 420 to 550°C, 450 to 510°C, 460 to 500°C, or 470 to 490°C.

[0070] In one aspect, in step c), the raw solution is introduced into the reactor at a rate of at least 1000kg / h (kilograms / hour). In one aspect, in step c), the raw solution is introduced into the reactor at a rate of at least 2000kg / h. In one aspect, in step c), the raw solution is introduced into the reactor at a rate of at least 5000kg / h. In one aspect, in step c), the raw solution is introduced into the reactor at a rate of at least 10000kg / h. In one aspect, in step c), the raw solution is introduced into the reactor at a rate of at least 15000kg / h. In one aspect, in step c), the raw solution is introduced into the reactor at a rate of at least 20000kg / h.

[0071] There may be no upper limit to the rate at which the feed solution is introduced into the reactor in step c). In one aspect, in step c), the feed solution is introduced into the reactor at a rate of no more than 1,000,000 kg / h. In one aspect, in step c), the feed solution is introduced into the reactor at a rate of no more than 100,000 kg / h.

[0072] Fluidizing gas

[0073] In one aspect, the method includes introducing a fluidizing gas into the reactor.

[0074] As will be appreciated by those skilled in the art, the fluidizing gas fluidizes the fluidizable heat-carrying particles in the reactor.

[0075] In one aspect, the method includes introducing a fluidizing gas into the reactor via a fluidizing gas inlet.

[0076] In one aspect, the method includes introducing a fluidizing gas into a reactor via fluidizable particles and a fluidizing gas inlet.

[0077] When the feed solution encounters the fluidizable heat carrier particles in the reactor, a vaporization zone is formed, in which the liquid evaporates and produces gaseous products via sugar cracking. This causes the superficial velocity of the gaseous products to increase, thereby entraining the fluidizable heat carrier particles. Thus, downstream of the feed solution inlet, the fluidizable heat carrier particles and the feed solution form a fast bed above the vaporization zone.

[0078] In one aspect, step c) comprises introducing a feedstock solution and a fluidizing gas into a reactor to pyrolytically crack the sugars to provide cracked products.

[0079] In one aspect, in step c), the feedstock solution is entrained in the fluidizing gas.

[0080] In one aspect, the fluidizing gas comprises water (eg, steam).

[0081] In one aspect, the fluidizing gas consists essentially of water (eg, steam).

[0082] In one aspect, the fluidizing gas consists of water (eg, steam).

[0083] In this document, "water" and "steam" are used interchangeably.

[0084] In one aspect, in step c), the fluidizing gas is introduced into the reactor at a rate of at least 100 kg / h. In one aspect, in step c), the fluidizing gas is introduced into the reactor at a rate of at least 500 kg / h. In one aspect, in step c), the fluidizing gas is introduced into the reactor at a rate of at least 1000 kg / h. In one aspect, in step c), the fluidizing gas is introduced into the reactor at a rate of at least 2000 kg / h. In one aspect, in step c), the fluidizing gas is introduced into the reactor at a rate of at least 4000 kg / h. In one aspect, in step c), the fluidizing gas is introduced into the reactor at a rate of at least 5000 kg / h.

[0085] There may be no upper limit to the rate at which the fluidizing gas is introduced into the reactor in step c). In one aspect, in step c), the fluidizing gas is introduced into the reactor at a rate of no more than 50,000 kg / h. In one aspect, in step c), the fluidizing gas is introduced into the reactor at a rate of no more than 20,000 kg / h.

[0086] Atomizing gas

[0087] In one aspect, the method includes introducing an atomizing gas into the reactor.

[0088] As will be appreciated by those skilled in the art, the atomizing gas is used to atomize the feed solution introduced into the reactor. The term atomizing refers to the breaking of a liquid into small droplets.

[0089] In one aspect, an atomizing gas and a feedstock solution are introduced into a reactor such that the feedstock solution is atomized by the atomizing gas.

[0090] In one aspect, the atomizing gas comprises water (eg, steam).

[0091] In one aspect, the atomizing gas consists essentially of water (eg, steam).

[0092] In one aspect, the atomizing gas consists of water (eg, steam).

[0093] In one aspect, in step c), the atomizing gas is introduced into the reactor at a rate of at least 50 kg / h. In one aspect, in step c), the atomizing gas is introduced into the reactor at a rate of at least 100 kg / h. In one aspect, in step c), the atomizing gas is introduced into the reactor at a rate of at least 200 kg / h. In one aspect, in step c), the atomizing gas is introduced into the reactor at a rate of at least 500 kg / h. In one aspect, in step c), the atomizing gas is introduced into the reactor at a rate of at least 800 kg / h. In one aspect, in step c), the atomizing gas is introduced into the reactor at a rate of at least 1000 kg / h. In one aspect, in step c), the atomizing gas is introduced into the reactor at a rate of at least 1200 kg / h.

[0094] There may be no upper limit to the rate at which the atomizing gas is introduced into the reactor in step c). In one aspect, in step c), the atomizing gas is introduced into the reactor at a rate of no more than 20,000 kg / h. In one aspect, in step c), the atomizing gas is introduced into the reactor at a rate of no more than 10,000 kg / h.

[0095] Introduced water

[0096] The method includes introducing water into a reactor.

[0097] Water can be introduced in the form of one or both of gas (steam) and liquid. Water can be introduced in various ways and by one or more different means, including, for example, via the feed solution and / or via the fluidizing gas and / or via the atomizing gas.

[0098] In one aspect, water is introduced into the reactor via an atomizing gas.

[0099] In one aspect, water is introduced into the reactor via the feed solution.

[0100] Cracking products

[0101] The cracked product comprises C1-C3 oxygen-containing compounds produced by pyrolytic cracking of the feed solution. The cracked product provided in step (c) is a crude product. The cracked product provided in step (c) comprises solids.

[0102] In one aspect, in step c), the cracked product is a solid dense cracked product.

[0103] In one aspect, the solid dense cracked products comprise C1-C3 oxygenates and solids.

[0104] In one aspect, step e) comprises separating solids from the solid dense cracked products cooled to the cooling temperature to provide solid-depleted cracked products, wherein the solids comprise solids selected from the group consisting of fluidizable heat-carrying particles, fragments of fluidizable heat-carrying particles, by-products from pyrolytic cracking of the feedstock solution, and mixtures thereof.

[0105] In one aspect, the solids-lean cracked product comprises C1-C3 oxygenates.

[0106] In one aspect, the solids-depleted cracked product contains a smaller amount of solids than the solids-dense cracked product.

[0107] The terms "lean" in "solids-lean" and "dense" in "solids-dense" are relative to each other.

[0108] In one aspect, the C1-C3 oxygenate comprises one, more or each of formaldehyde (C1), glycolaldehyde (C2), glyoxal (C2), methylglyoxal (C3) and acetol (C3). For most purposes, C2 and C3 oxygenates are the most valuable.

[0109] In one aspect, the cracking product comprises a mixture of two or more C1-C3 oxygenates. The mixture may be referred to interchangeably as a C1-C3 oxygenate mixture, a C1-C3 oxygenate product, or a C1-C3 oxygenate.

[0110] In one aspect, the cracking product comprises glycolaldehyde.

[0111] In one aspect, the cracking products include glycolaldehyde in a major portion.

[0112] In one aspect, the cracked product comprises glycolaldehyde in an amount of at least 10 wt.%, such as at least 20 wt.%, at least 30 wt.%, at least 40 wt.%, at least 50 wt.%, at least 60 wt.% or at least 70 wt.%, based on the total weight of the cracked product.

[0113] In one aspect, the cracked product comprises one or more glycolaldehydes or glyoxals in an amount of at least 10 wt.%, e.g., at least 20 wt.%, at least 30 wt.%, at least 40 wt.%, at least 50 wt.%, at least 60 wt.%, at least 70 wt.%, or at least 80 wt.%, based on the total weight of the cracked product.

[0114] In one aspect, the cracked product comprises one or more methylglyoxal or acetol in an amount of at least 3 wt.%, such as at least 5 wt.%, or at least 7 wt.%, based on the total weight of the cracked product.

[0115] In one aspect, the total amount of C1-C3 oxygenates in the cracked product is no greater than 99 wt.%, eg, no greater than 95 wt.% or no greater than 90 wt.%, based on the total weight of the cracked product.

[0116] In one aspect, "based on the total weight of the cracked product" refers to the cracked product provided in step (c) (eg, a solid dense cracked product).

[0117] In one aspect, "based on the total weight of cracked products" refers to the cracked products after step (e) (eg, solids-depleted cracked products).

[0118] In one aspect, "based on the total weight of the cracked products" refers to the cracked products excluding solids.

[0119] d) Cooling the cracked products downstream of the reactor to a cooling temperature

[0120] The process comprises cooling the cracked products downstream of the reactor to a cooling temperature of 230°C to 390°C.

[0121] The "cooling temperature" corresponds to the average temperature of the cracking products after cooling step d).

[0122] In one aspect, the cooling temperature is from 250 to 390°C.

[0123] In one aspect, the cooling temperature is from 260 to 385°C.

[0124] In one aspect, the cooling temperature is from 270 to 380°C.

[0125] In one aspect, the cooling temperature is from 300 to 375°C.

[0126] In one aspect, the cooling temperature is from 330 to 370°C.

[0127] In one aspect, step d) comprises indirectly cooling said cracked products to said cooling temperature.

[0128] In one aspect, step d) comprises cooling said cracked product to said cooling temperature using a cooling device.

[0129] In one aspect, the cooling device is a heat exchanger.

[0130] In one aspect, the cooling device is an indirect heat exchanger.

[0131] In one aspect, step d) is the earliest step of cooling the cracked products.

[0132] In one aspect, no step of cooling the cracked products is performed within the reactor.

[0133] In one aspect, no step of cooling the cracked products is performed prior to step d).

[0134] In one aspect, step d) is performed at a location below the location where the reactor is located (relative to sea level).

[0135] In one aspect, the cooling device (eg, a heat exchanger) is disposed at a location below (relative to sea level) where the reactor is disposed.

[0136] In one aspect, the lowest surface of the cooling device (eg, heat exchanger) is disposed at a location (relative to sea level) below where the lowest surface of the reactor is disposed.

[0137] In one aspect, no cooling step is performed within the reactor.

[0138] e) separating solids from the cracked products cooled to the cooling temperature, wherein the solids include solids selected from the group consisting of fluidizable heat-carrying particles, fragments of fluidizable heat-carrying particles, by-products from pyrolytic cracking of a feed solution, and mixtures thereof

[0139] The method includes separating solids from cracked products cooled to the cooling temperature, wherein the solids include solids selected from the group consisting of fluidizable heat-carrying particles, fragments of fluidizable heat-carrying particles, byproducts from pyrolytic cracking of a feedstock solution, and mixtures thereof.

[0140] In one aspect, step e) comprises separating at least 50 wt.%, at least 60 wt.%, at least 70 wt.%, at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.% of solids from the cracked product cooled to the cooling temperature, based on the total weight of the solids.

[0141] In one aspect, step e) comprises separating no greater than 99.999 wt.%, e.g., no greater than 99.99 wt.%, no greater than 99.9 wt.%, no greater than 99.5 wt.%, or no greater than 99 wt.% of solids from the cracked product cooled to the cooling temperature, based on the total weight of the solids.

[0142] In one aspect, step e) comprises separating substantially all of the solids from the cracked products cooled to the cooling temperature.

[0143] In one aspect, step e) comprises separating the solids from the cracked products using a physical separation device.

[0144] In one aspect, the physical separation device is a particle separator.

[0145] In one aspect, the physical separation device is a low capacity separator.

[0146] In one aspect, the physical separation device is a change-of-direction separator.

[0147] In one aspect, the physical separation device is a cyclone separator.

[0148] In one aspect, the physical separation device is a filter.

[0149] In one aspect, the filter is selected from the group consisting of: a metal filter and a ceramic filter.

[0150] In one aspect, the filter comprises a filter element.The filter element can be considered as a material (filter medium) for filtering cracked products containing solids, thereby separating the solids from the cracked products.

[0151] In one aspect, the filter element comprises a filter surface. The filter surface may also be referred to as a filter area. The filter surface may be considered to be the outer surface of the filter element. The filter surface may be considered to be an interface through which cracked products including solids enter the filter element in use. The filter surface may be used to separate the solids from the cracked products. In this way, the solids may be collected on the filter surface in use.

[0152] In one aspect, the filter element comprises a porous matrix.

[0153] In one aspect, the porous matrix is ​​selected from: a porous fiber matrix; a porous mesh matrix; a porous matrix comprising sintered spheres; a porous metal matrix (eg, a sintered porous metal matrix); a porous ceramic matrix; and combinations thereof.

[0154] In one aspect, the porous matrix is ​​a porous fiber matrix. In one aspect, the porous fiber matrix is ​​a porous fiber metal matrix. In one aspect, the porous fiber matrix is ​​a sintered porous fiber metal matrix.

[0155] In one aspect, the filter comprises a plurality of filter elements. Each filter element can be independently as described herein.

[0156] In one aspect, the filter is a candle filter.

[0157] In one aspect, the filter is a bag filter.

[0158] In one aspect, the filter has an efficiency of at least 99.9% for particles having a size of at least 50 microns, such as at least 30 microns, at least 20 microns, or at least 10 microns.

[0159] In one aspect, multiple physical separation devices are used. Each physical separation device can independently be as described herein.

[0160] Dwell time

[0161] In one aspect, the average residence time of the cracked products between step d) and step e) is no greater than 50 seconds, e.g., no greater than 45 seconds, no greater than 40 seconds, no greater than 35 seconds, no greater than 30 seconds, no greater than 25 seconds, or no greater than 20 seconds.

[0162] In one aspect, the average residence time of the cracked products between step d) and step e) is at least 0.1 s, such as at least 1 s, at least 3 s, at least 5 s, at least 8 s, at least 10 s, at least 12 s, or at least 15 s.

[0163] In one aspect, the average residence time of the cracked products between step d) and step e) is from 0.1 to 50 s, such as from 1 to 40 s, or from 2 to 20 s.

[0164] “Between step d) and step e)” means between the end of step d) and the start of step e). When a cooling device is used in step d), “between step d) and step e)” means between the exit of the cracked products from the cooling device to step e). When a separation device is used in step e), “between step d) and step e)” means between step d) and the entry of the cracked products into the separation device. When a cooling device is used in step d) and a separation device is used in step e), “between step d) and step e)” means between the exit of the cracked products from the cooling device and the entry of the cracked products into the separation device.

[0165] In one aspect, the average residence time of the cracked products in step e) is 5 to 50 s, e.g., 8 to 30 s, 10 to 25 s, 14 to 22 s, 15 to 20 s, 16 to 17 s.

[0166] "In step e)" refers to the duration of the separation process in step e). When a physical separation device is used in step e), "in step e)" refers to the time from when the cracked products enter the physical separation device to when the cracked products leave the physical separation device. For example, when a filter is used in step e), "in step e)" refers to the time from when the cracked products enter the filter to when the cracked products leave the filter.

[0167] Apparent velocity

[0168] In one aspect, when a filter is used in step e), the superficial velocity of the cracked products at the filtering surface of the filter is 0.1 to 3 cm / s, e.g., 0.15 to 2.5 cm / s, 0.2 to 2 cm / s, 0.25 to 1.5 cm / s, 0.3 to 1 cm / s, 0.3 to 0.75 cm / s, 0.35 to 0.6 cm / s, or 0.4 to 0.5 cm / s.

[0169] One skilled in the art will know how to calculate the superficial filtration velocity.

[0170] solid

[0171] The solid includes a solid selected from the group consisting of fluidizable heat-carrying particles, fragments of fluidizable heat-carrying particles, by-products from pyrolytic cracking of a feedstock solution, and mixtures thereof.

[0172] When the fluidizable heat-carrying particles are fluidized in the reactor, a certain amount of particles can be transported out of the reactor, for example, via the outlet of the reactor. Particle fragments can be formed by abrasion or breakage of the particles, for example, by mechanical interactions between the particles themselves and / or between the particles and the reactor.

[0173] The byproducts may be sticky and / or viscous. Without removal of the byproducts, these byproducts may adhere to the filter (when present) and / or equipment downstream of the reactor. For example, when a filter is used, over time, the byproducts may form a larger and larger sticky filter cake on the filter, necessitating eventual removal of the filter cake.

[0174] In one aspect, the solids consist essentially of solids selected from the group consisting of fluidizable heat-carrying particles, fragments of fluidizable heat-carrying particles, byproducts from pyrolytic cracking of a feedstock solution, and mixtures thereof.

[0175] In one aspect, the solid consists essentially of solids selected from the group consisting of fluidizable heat-carrying particles, fragments of fluidizable heat-carrying particles, byproducts from pyrolytic cracking of a feedstock solution, and mixtures thereof.

[0176] In one aspect, the solid consists of a solid selected from the group consisting of fluidizable heat-carrying particles, fragments of fluidizable heat-carrying particles, byproducts from pyrolytic cracking of a feedstock solution, and mixtures thereof.

[0177] In one aspect, the process is suitable for processing greater than 1,000 tons of sugar per cracking reactor per year, e.g., greater than 5,000 tons of sugar per cracking reactor per year, greater than 10,000 tons of sugar per cracking reactor per year, greater than 50,000 tons of sugar per cracking reactor per year, greater than 100,000 tons of sugar per cracking reactor per year, or greater than 1,000,000 tons of sugar per cracking reactor per year, based on the weight of dry sugar.

[0178] In one aspect, the process is suitable for processing no more than 10,000,000 tons of sugar per cracking reactor per year, such as no more than 5,000,000 tons of sugar per cracking reactor per year, or no more than 2,000,000 tons of sugar per cracking reactor per year, based on the weight of dry sugar.

[0179] In one aspect, the pyrolytic cracking process is run as a continuous process.

[0180] Further process steps

[0181] In one aspect, the method comprises one or more further separation steps between step c) and step d), wherein the separation or each separation between step c) and step d) comprises separation of solids from the cracked products, wherein the solids comprise solids selected from the group consisting of fluidizable heat-carrying particles, fragments of fluidizable heat-carrying particles, by-products from pyrolytic cracking of the feed solution, and mixtures thereof. In one aspect, the separation or each separation between step c) and step d) is performed in a reactor.

[0182] In one aspect, the separation step or each separation step between step c) and step d) comprises separating at least 50 wt.%, at least 60 wt.%, at least 70 wt.%, at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.% of the solids from the cracked products, based on the total weight of the solids.

[0183] In one aspect, the separation step or each separation step between step c) and step d) comprises separating no more than 99.9 wt.%, e.g., no more than 99.5 wt.%, no more than 99 wt.%, no more than 95 wt.%, no more than 90 wt.%, or no more than 80 wt.% of solids from the cracked product, based on the total weight of the solids.

[0184] In one aspect, the method comprises a primary separation and / or a secondary separation between step c) and step d). In one aspect, the primary separation and / or the secondary separation is performed in a reactor.

[0185] In one aspect, the primary separation comprises separating solids from the cracked products, wherein the solids comprise solids selected from the group consisting of fluidizable heat-carrying particles, fragments of fluidizable heat-carrying particles, byproducts from pyrolytic cracking of a feedstock solution, and mixtures thereof.

[0186] In one aspect, the primary separation comprises separating at least 50 wt.%, at least 60 wt.%, at least 70 wt.%, at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.% of the solids from the cracked products based on the total weight of the solids.

[0187] In one aspect, the primary separation comprises separating no greater than 99.9 wt.%, e.g., no greater than 99.5 wt.%, no greater than 99 wt.%, no greater than 95 wt.%, no greater than 90 wt.% or no greater than 80 wt.% of solids from the cracked products based on the total weight of the solids.

[0188] In one aspect, the secondary separation comprises separating solids from the cracked products, wherein the solids comprise solids selected from the group consisting of fluidizable heat-carrying particles, fragments of fluidizable heat-carrying particles, byproducts from pyrolytic cracking of a feedstock solution, and mixtures thereof.

[0189] In one aspect, the secondary separation comprises separating at least 50 wt.%, at least 60 wt.%, at least 70 wt.%, at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.% of the solids from the cracked products based on the total weight of the solids.

[0190] In one aspect, the secondary separation comprises separating no greater than 99.9 wt.%, e.g., no greater than 99.5 wt.%, no greater than 99 wt.%, no greater than 95 wt.%, no greater than 90 wt.%, or no greater than 80 wt.% of solids from the cracked products based on the total weight of the solids.

[0191] One or more further separation steps between step c) and step d) may help to reduce the amount of solids in the cracked product before step d). In this way, less energy is wasted in cooling the heat-carrying particles in cooling step d).

[0192] The process according to the invention may provide a cracked product which is subjected to one or more further processing steps. For example, after step d), the cracked product may be further processed by one or more of chemical conversion (e.g. conversion into another product, e.g. by a hydrogenation reactor), purification (e.g. reduction of the presence of any impurities) and separation (e.g. providing a specific oxygenate or a specific mixture of oxygenates).

[0193] According to another aspect of the present invention, there is provided a system for pyrolytic cracking of sugar into C1-C3 oxygenated compounds, the system comprising:

[0194] a) an aqueous raw material solution containing sugar;

[0195] b) a fluidized bed cracking reactor configured to pyrolytically crack sugars and comprising fluidizable heat-carrying particles to provide cracked products comprising C1-C3 oxygenates, wherein the temperature of the cracked products at the reactor outlet is at least 400°C;

[0196] c) means for cooling the cracked products downstream of the reactor to a cooling temperature of 230° C. to 390° C.; and

[0197] d) a separation device configured to separate solids from the cracked products cooled to the cooling temperature, wherein the solids include solids selected from the group consisting of fluidizable heat-carrying particles, fragments of fluidizable heat-carrying particles, by-products from pyrolytic cracking of the feed solution, and mixtures thereof.

[0198] According to another aspect of the present invention, there is provided a system for thermally cracking sugar into C1-C3 oxygen-containing compounds, the system comprising:

[0199] a) a fluidized bed cracking reactor configured to pyrolytically crack sugars to provide cracked products comprising C1-C3 oxygenates; and

[0200] b) means for cooling the cracked products to a cooling temperature downstream of the reactor,

[0201] The means for cooling the cracked products is arranged at a position below the reactor position (relative to sea level).

[0202] In one aspect, the reactor and the means for cooling are separate physical structures.

[0203] According to another aspect of the present invention, there is provided a system for thermally cracking sugar into C1-C3 oxygen-containing compounds, the system comprising:

[0204] a) a fluidized bed cracking reactor configured to pyrolytically crack sugars to provide cracked products comprising C1-C3 oxygenates; and

[0205] b) means for cooling the cracked products downstream of the reactor to a cooling temperature.

[0206] In one aspect, the means for cooling is a cooling device.A cooling device may be as defined herein.

[0207] Any aspect of the present invention may include any feature of any other aspect of the present invention. The feature of any aspect of the present invention may be as described herein with respect to any other aspect of the present invention. For example, a system according to the present invention may be characterized by any feature of a method according to the present invention, and vice versa.

[0208] BRIEF DESCRIPTION OF THE DRAWINGS

[0209] Embodiments of the present invention are described by way of example and with reference to the accompanying drawings. The drawings show only examples of embodiments of the invention and are therefore not to be considered limiting of its scope, as the invention may admit to other alternative embodiments.

[0210] Figure 1 shows a cross-sectional side view of a cracking reactor forming part of a system according to one embodiment of the present invention;

[0211] Figure 2 Shows Figure 1 A top view of the intermediate cracking reactor;

[0212] Figure 3shows a cross-sectional side view of a reheater forming part of a system according to one embodiment of the present invention;

[0213] Figure 4 shows a cross-sectional side view of a system according to one embodiment of the present invention (not all components of the system are shown), the system comprising a cracking reactor in fluid communication with a reheater;

[0214] Figure 5 A block diagram of a system according to one embodiment of the present invention is shown (not all components of the system are shown);

[0215] Figure 6 shows an example temperature profile of the fluidizable particle inlet, reactor outlet, and filter;

[0216] Figure 7 The carbon yield in glycolaldehyde carbon recovery and the carbon yield in C1-C3 oxygenates (total) carbon recovery are shown as a function of filtration temperature;

[0217] Figure 8 is a schematic diagram of a candle filter; and

[0218] Fig. 9 A schematic diagram of a cracking reactor forming part of a system according to one embodiment of the present invention is shown.

[0219] Position number

[0220] 1. Cracking reactor

[0221] 2. Cracking riser

[0222] 3. First particle separator

[0223] 4. Second particle separator

[0224] 5. Cooling section

[0225] 6. Primary fluidizing gas inlet

[0226] 7. Fluidizable particle inlet

[0227] 8. Raw material and atomizing gas inlet

[0228] 9. Product export

[0229] 10. Fluidizable particle outlet

[0230] 11. Reheater

[0231] 12. Fuel and combustion air inlet

[0232] 13. Combustion Chamber

[0233] 14. Reheater fluidizable particle inlet

[0234] 15. Reheater riser

[0235] 16. Reheater fluidized particle separator

[0236] 17. Reheater fluidized particle outlet

[0237] 18. Reheater gas outlet

[0238] 19. Second reheater fluidized particle separator

[0239] 20. Stripper

[0240] 21. Secondary fluidizing gas inlet

[0241] 22. Secondary reheater fluidizing and stripping gas inlet

[0242] O'. Reactor outlet

[0243] 100.Heat exchanger

[0244] 200. Physical separation devices (e.g. filters) for gas / solid filtration

[0245] 300. Cracking reactor

[0246] 301. Fluidizing gas

[0247] 302. Raw material solution

[0248] 303. Atomized gas

[0249] 304. Raw material and atomizing gas inlet (feed nozzle)

[0250] 305.First particle separator

[0251] 306. Recirculating heat-carrying particles

[0252] 307. Rough dividing line used to separate dense phase and lean phase

[0253] 308.Heating device

[0254] 309. Cooling Steps

[0255] 310. Separation step DETAILED DESCRIPTION OF THE INVENTION

[0257] like Figure 1 and Figure 4As shown, the cracking reactor 01 is rectangular in the vertical direction. A riser 02 is provided in the cracking reactor, which is rectangular and has a small cross-sectional area relative to the height. This promotes the possibility of fluidized heat-carrying particles having a low residence time in the riser 02. At the lower part of the riser 02, a fluidizing gas inlet 06 is provided. The primary fluidizing gas inlet 06 is suitable for providing fluidizing gas to the riser 02. At the lower part of the riser 02, an inlet 07 for fluidized heat-carrying particles is also provided. The reactor 01 further includes an outlet O'.

[0258] The fluidizing gas helps promote the movement of the fluidizable heat carrier particles from the fluidizable heat carrier particle inlet 07 to the feedstock inlet 08 and toward the top of the riser 02. In addition, the fluidizing gas can also be used to pre-treat the fluidizable heat carrier particles before the particles contact the feedstock solution.

[0259] The feedstock and atomizing gas inlet 08 is located in the riser 02 above the particle inlet 07 and the fluidizing gas inlet 06. The feedstock inlet 08 enables the feedstock solution to be supplied to the riser 02. Figure 1 As shown, the feed inlet 08 is located at the lower portion of the riser 02, although its position may be adjusted according to process requirements.

[0260] After the raw material solution and the fluidizable particles interact in the riser 02, they are separated in the first particle separator 03 when leaving the riser. In some embodiments, the first particle separator 03 is designed to quickly separate the fluidizable particles and the cracked products (including C1-C3 oxygen-containing compounds), because such a fast separation is very beneficial to the whole process. Therefore, the particle separator 03 can be a low residence time type.

[0261] exist Figure 1 and Figure 2 In the embodiment shown, the first particle separator 03 comprises outlet pipes which change the upward flow direction of the flow out of the riser 02 by approximately 180° so that it changes to a downward flow direction within the cracking reactor 01 and outside the riser 02, which is referred to herein as a change-of-direction particle separator.

[0262] exist Figure 4 In the embodiment shown, the first particle separator 03 induces separation of gas and particles, forcing the riser gas and solids entering the reactor 1 to leave in a tangential direction relative to the wall of the reactor 01, thereby achieving separation. A portion of the particles settle to the bottom of the cracking reactor 01 after leaving the first particle separator 03.

[0263] The features of the riser 02, the position of the feed inlet 06 and the low residence time of the first particle separator 03 provide the possibility of a very short contact time between the fluidizable particles and the feed solution. Of course, this also depends on process parameters such as volume flow rate and specific dimensions, which need to be adjusted according to process requirements.

[0264] An optional cooling section 05 is provided in the cracking reactor 01. Figure 1 In the embodiment shown, this cooling section is located between the first particle separator 03 and the outlet O′ of the reactor 01 .

[0265] Cracked products are extracted from the cracking reactor 01 via the product outlet 09 .

[0266] exist Figure 1 and Figure 4 In the embodiment shown, an optional second particle separator 04 is provided for separating more fluidizable particles from the product stream prior to extraction of the cracked products.

[0267] The second particle separator 04 (e.g., a cyclone separator) may have a higher separation efficiency than the separate redirecting separator 03. The gas outlet of the cyclone separator 04 is connected to the product outlet 09, and the particles from the particle outlet of the cyclone separator 04 are sent to the bottom of the cracking reactor 01, where the fluidizable particles are kept in a fluidized state by using a fluidizing gas supplied from a secondary fluidizing gas inlet 21. The distribution of the fluidizing gas over the horizontal cross-section of the vessel 1 is ensured by, for example, using a sprinkler. At the bottom of the cracking reactor 01, the particle outlet 10 allows the fluidizable particles that have been used in the cracking reactor 01 to be extracted and transported elsewhere, for example, for reheating in another reactor. In Figure 1-4 Although not shown, stripping of the product gas (cracked products) before or after the fluidizable particle outlet 10 is also envisaged.

[0268] Figure 2 yes Figure 1 01. As shown, the riser 02 is located in the center of the horizontal cross section of the cracking reactor 01. In addition, multiple outlet pipes forming a first particle separator 03 and a second particle separator 04 located in a non-central position of the cracking reactor 01 are shown.

[0269] exist Figure 3 and Figure 4In FIG. 1 , a reheater 11 is shown for reheating fluidizable particles coming out of a cracking reactor 01. A reheater particle inlet 14 is in fluid communication with the fluidizable particle outlet 10, and a reheater fluidizable particle outlet 17 is in fluid communication with the fluidizable particle inlet 07. The reheater 11 also comprises a riser-type fluidized bed and a reheater riser 15, wherein a combustion chamber 13 is arranged in fluid communication with the lower part of the reheater riser 15. The fuel and combustion air inlet 12 enables fuel and combustion air to be supplied to the combustion chamber 13, which during operation provides heat to the reheater riser 15. The reheater fluidizable particle inlet 14 is arranged to be located at the lower part of the reheater riser 15, so that the fluidizable particles coming out of the cracking reactor 01 can enter the reheater riser 15; in the reheater riser 15, these particles are fluidized by the upward flow of hot gas provided by the combustion chamber 13 and are heated in the process. The connection between the combustion chamber 13 and the reheater fluidizable particle inlet 14 is intentionally designed to reduce or prevent the fluidizable particles from falling from the riser 15 into the combustion chamber 13. This design can take many different forms. For example, in Figure 3 and Figure 4 In FIG. 1 , this is shown by the constriction between 13 and 15 which results in an increased gas velocity, thereby preventing or reducing the falling of the particles. After reheating, the fluidizable particles are separated from the combustion gases and sent back to the cracking reactor 01. Figure 3 In the embodiment of the present invention, the reheater particle separator 16 is a cyclone separator that allows gas to leave the reheater 11 via a reheater gas outlet 18, while the separated fluidizable particles leave the reheater 11 via a reheater fluidizable particle outlet 17, which is connected to the fluidizable particle outlet of the cyclone separator of the reheater 11. It should be understood that the degree of separation in the particle separator depends on various process parameters, such as pressure loss in the separator, flow rate, particle size, etc., as known in the art.

[0270] exist Figure 4 In the embodiment of the present invention, the reheater first particle separator 16 is similar to the cracking reactor first particle separator 03. Figure 4 The embodiment is also equipped with a two-stage cyclone particle separator 19. Both particle separators 16, 19 convey the fluidizable particles to the bottom of the reheater 11. At the lowest position of the reheater 11, a section 20 for stripping excess oxygen from the fluidizable particles is provided. Figure 4 In an embodiment, the secondary fluidizing and stripping gas inlets 22 for the reheater 11 and section 20 are distributed over the cross section using, for example, sprinklers or other methods. Figure 4 There may be additional fluidizing gas inlets in the reheater 11, but these are not shown. It is also envisaged that Figure 1-4Stripping of the product gas (cracked products) before or after the outlet 10 for the fluidizable particles in the fluidized phase is possible but not shown in the figure.

[0271] refer to Figure 5 , showing Figure 4 The system includes Figure 4 In other embodiments, the system includes Figure 1 cracking reactor instead of Figure 4 The system may also include a cooling device, such as a heat exchanger 100, for cooling the product gas (cracked product). The system also includes a physical separation device 200 (discussed below). Figure 5 In the embodiment of the present invention, the heat exchanger 100 is arranged downstream of the reactor 1, and the physical separation device 200 is arranged downstream of the heat exchanger 100. Those skilled in the art will understand that the system may include additional components, such as one or more additional cooling steps or other unit operations.

[0272] exist Figure 5 In the embodiment of the present invention, the product gas passes through the product outlet 09 to the heat exchanger 100, then to the physical separation device 200, and then to other downstream equipment. Figure 5 In an embodiment, the physical separation device 200 is a filter, in particular a candle filter, wherein the filter element provided by the candles of the candle filter comprises a porous matrix of metal fibers. More specifically, the metal fibers comprise a nickel-chromium-molybdenum alloy (Alloy 59).

[0273] Figure 8 A schematic diagram of a candle filter is shown. The candle filter includes a housing having a solid / cracked product inlet, a solid outlet, and a cracked product / gas outlet, wherein cracked products containing solids are guided through the solid / cracked product inlet, and separated solids are guided through the solid outlet, and cracked products from which solids have been separated are guided through the cracked product / gas outlet. A plurality of candles are arranged in the housing. Each candle includes a filter element for separating solids from cracked products. Each filter element includes a filter surface (or filter area). The filter surface can be considered as an interface, and in use, cracked products including solids enter the filter element through the interface. The filter surface is the outer surface of the filter element. In use, cracked products enter each filter element via the filter surface, so that solids are separated from cracked products by each filter element. The separated solid is removed from the housing through the solid outlet. The solid outlet can be equipped with a valve system (not shown) to prevent gas from escaping and remove the collected solids.

[0274] In other embodiments, other physical separation devices and other filters are contemplated. For example, candle filters are described in Gasification (Higman, C., 2 nd The function and operation of candle filters are known to those skilled in the art and will not be described in further detail here.

[0275] In some embodiments (e.g., Figure 5 In some embodiments, the step of cooling the cracked products using the heat exchanger 100 is the earliest step of cooling the cracked products. In some embodiments, the step of cooling the cracked products is not performed in the reactor 01. In some embodiments, other steps of cooling the cracked products are not performed before the step of cooling the cracked products using the heat exchanger 100.

[0276] In this particular embodiment, the cracked products pass through a first particle separator 03 and a second particle separator 04 (as described above) before passing through the product outlet 09. These particle separators 03, 04 reduce the amount of heat-carrying particles in the cracked products.

[0277] The separation device 200 separates solids from cracked products, wherein the solids include solids selected from the following: fluidizable heat-carrying particles, fragments of fluidizable heat-carrying particles, by-products from pyrolysis cracking of the feed solution (the latter is discussed below), and mixtures thereof. In this particular embodiment, the solids consist essentially of solids selected from the following: fluidizable heat-carrying particles, fragments of fluidizable heat-carrying particles, by-products from pyrolysis cracking of the feed solution, and mixtures thereof. By separating the solids from the cracked products, the impact of these solids on the equipment downstream of the reactor 1 is reduced. In use, the cracked products leave the reactor 01 via the product outlet 09 and pass through the heat exchanger 100 before passing through the separation device 200.

[0278] The heat exchanger 100 is disposed at ground level, whereas the reactor 01 is disposed elevated relative to the ground level.

[0279] As will be appreciated by those skilled in the art, water may be introduced into the reactor in various ways, including, for example, via a feed solution, a fluidizing gas, and / or an atomizing gas. However, it should be understood that the fluidizing gas and / or the atomizing gas may include an inert gas, such as N2, CO, CO2, CH4, or a mixture thereof.

[0280] Example 1

[0281] In a system according to one embodiment of the present invention, an aqueous feed solution (glucose syrup) containing about 60 wt.% glucose and 40 wt.% water (based on the total weight of the feed solution) is subjected to thermal cracking (i.e. Figure 4, but wherein the optional cooling step 25 is omitted). The aqueous raw material solution is fed into the reactor at a rate of 15 kg / h.

[0282] The cracking reactor 1 is operated at a pressure of about 2.5 bara (absolute) (at the outlet O' of the reactor), the heat carrier temperature at the inlet 07 is about 580° C., and the temperature at the reactor outlet O' is about 475° C. During the operation of the reactor 01 for a duration of about 15 hours, the temperature of the filter 200 (e.g., at the inlet of the filter 200) is gradually reduced from about 400° C. to 340° C. by increasing the cooling rate of the indirect cooling heat exchanger 100 located between the reactor 01 and the filter 200. Figure 6 The temperature profile during this 15 hour run is shown. The feed solution was injected into reactor 1 using a gas assisted internal mixing atomizing nozzle (i.e. feed and atomizing gas inlet 08) entering from the bottom of riser 02, the atomizing gas flow rate was 15 kg / h of nitrogen, the fluidizing steam gas flow rate was 7 kg / h of steam through 6, and 12 kg / h of steam was added through inlet 21.

[0283] The average gas residence time (average residence time of the cracked products) in the filter 200 is about 16-17 seconds (although those skilled in the art will appreciate that this will vary with temperature). The superficial filtration velocity (i.e., the superficial velocity at the filter surface of the filter) is 0.42 to 0.46 cm / s.

[0284] refer to Figure 8 When the cracked products containing solids flow toward the candle in use, the cracked products containing solids are distributed on the candle and flow through the filter element of the candle. The cracked products enter the filter element of the candle via the filter surface of the candle. The average superficial velocity at which the cracked products containing solids flow through the filter surface of the candle can be calculated by the following formula:

[0285] U=Q / Area

[0286] Where Q is the actual gas volume flow rate in m 3 / s, area is the filter surface area, unit is m 2 A person skilled in the art will know how to calculate the actual gas flow and correct it for pressure and temperature. The filter element of the candle can be made of different materials and have different porosities, such as Figure 8 The gas velocity U at the filter surface will be roughly independent of the material type.

[0287] A solids-depleted cracked product is obtained after filtering at filter 200. This solids-depleted cracked product contains substantially no solids.

[0288] After filtering at filter 200, condense the stream of cracked product (depleted solid).Measure the concentration of glycolaldehyde of cracked product (depleted solid) by HPLC at different times during 15 hours of operation.In addition, measure the concentration of C1-C3 oxygenates of cracked product (depleted solid) by HPLC at different times during 15 hours of operation.Measure the productivity of C1-C3 oxygenates (i.e. all C1-C3 oxygenates).Use water as inert reference, calculate the productivity or recovery of glycolaldehyde based on carbon at each filtering temperature.The recovery or productivity of glycolaldehyde is the percentage of carbon recovered as carbon in glycolaldehyde in the raw material solution.All C1-C3 oxygenates are carried out the same calculation. Figure 7 The carbon yield or recovery of glycolaldehyde and C1-C3 oxygenates (all C1-C3 oxygenates) as a function of filtration temperature is shown. It is observed that the glycolaldehyde yield increases significantly with decreasing filter temperature, i.e., from less than 40% to about 50%. It is also observed that the C1-C3 oxygenate yield increases significantly with decreasing filter temperature, i.e., from about 65% to about 78%.

[0289] Thus, the present inventors surprisingly found that the yield of C1-C3 oxygenates (eg glycolaldehyde) depends on the filtration temperature, which is preferably below 370°C, more preferably below 350°C.

[0290] Therefore, the inventors are surprised to find that, by cooling the cracked product downstream of reactor 01 to a cooling temperature, the method provides an improvement in efficiency and design, while achieving a good yield of C1-C3 oxygenates (e.g., ethanolaldehyde). In particular, by means of a downstream cooling step, such as not cooling in the reactor, cooling heat exchanger 100 and reactor 01 can be arranged at positions different from each other. In this way, reactor 01 can be designed to not need to accommodate cooling heat exchanger 100, which reduces design complexity and installation complexity, and improves space efficiency and ease of operation. In terms of reducing installation complexity, cooling heat exchanger 100 can be located at a position closer to the ground than reactor 01, and is installed independently of reactor 01. In terms of space efficiency and ease of operation, since the design of reactor 01 does not need to accommodate cooling heat exchanger 100, reactor 01 can be more compact and lighter in quality. In addition, for example, once reactor 01 is installed, cooling heat exchanger 100 can be connected to reactor 01 (e.g., in a modular manner). Cooling downstream of the reactor 01 to a cooling temperature unexpectedly brings about these advantages as well as a good yield of C1-C3 oxygenates.

[0291] The above advantages are particularly beneficial in industrial production environments, where large amounts of capital expenditures (CAPEX) and operating expenditures (OPEX) can be spent on building and maintaining process equipment, and product yield is a major consideration.

[0292] Example 2

[0293] This example illustrates another aspect of the pyrolytic cracking of sugars in an industrial setting according to the present invention. Fig. 9 In the system and method, a fluidized bed cracking reactor (300) is used. Inside the reactor (300), a fluidizing gas (301) is added through a gas distributor (not shown in detail) at the bottom of the reactor (300) to fluidize the heat-carrying particles used for the pyrolytic cracking of sugars. The gas distributor distributes the fluidizing gas (301) over the entire cross-section of the reactor (300). Fig. 9 In the embodiment of the present invention, the gas distributor is a gas sparger with a downward direction (although other directions, such as upward, horizontal or directions in between are also possible). The liquid sugar feedstock (302) is mixed with the atomizing gas (303) in the feed nozzle (304) to provide a fine spray of liquid droplets before contacting the heat carrying particles in the reactor (300). Fig. 9 Only one feed nozzle (304) is shown, but it should be understood that multiple feed nozzles can be used and placed at different locations within the reactor (300) to ensure that the feedstock (302) is well distributed within the reactor (300).

[0294] Therefore, the liquid sugar raw material (302) in contact with the heat-carrying particles is cracked in the reactor to obtain a cracked product rich in C1-C3 oxygen-containing compounds in the gas phase. Cracking and evaporation of feed water increase the gas volume flow rate, thereby increasing the upward gas flow rate. The gas flows upward and enters the cyclone separator (305) (first particle separator). Inside the cyclone separator (305), most (e.g., at least 95wt.%) of the entrained heat-carrying particles are separated and recycled (306) to the lower part of the reactor (300). The outlet of the reactor O' transports the cracked product gas to downstream processing. It should be understood that the particle separator (305) can be configured in different ways, and multiple particle separators can be used. For example, parallel cyclone separators, or series cyclone separators, or a combination thereof can be used. Surface filtration filters can also be used.

[0295] The lower part of the reactor (300) operates in a dense fluidized bed with a superficial gas velocity of less than about 2 m / s (meters per second). The upper part of the reactor 300 operates in a lean phase with a superficial gas velocity greater than about 3 m / s. The demarcation between the operating modes (dense or lean) is not clear-cut and may also depend on the physical properties of the gas and solids, such as density, gas viscosity, and particle size and shape. The increase in gas flow rate during the cracking process may also depend on the feed concentration and yield. Fig. 9 In FIG. 1 , the approximate boundary separating the dense phase and the lean phase is represented by curve ( 307 ). Curve ( 307 ) also shows the approximate position of the upper surface of the dense fluidized bed of heat carrying particles.

[0296] In the dense fluidized bed of heat-carrying particles, the indirect heating device (308) is positioned to bring the energy required for the pyrolysis cracking step and take into account heat losses and product gas losses. The heating device (308) can be a resistive electric heating rod or other type or indirect heating method. The dense mode of fluidization ensures good mixing and transportation of the heat-carrying particles in the reactor (300).

[0297] The heating device (308) may also be positioned external to the reactor (300), and additional means may be provided for transferring heat-carrying particles between the reactor (300) and the heating device (308). This configuration is not shown.

[0298] like Fig. 9 As shown, downstream of the outlet O' of the reactor (300), there is a cooling step (309) followed by a solid separation step (310).

[0299] Fig. 9 The system can be used for pyrolysis cracking of sugar under industrial conditions. As described in Example 2 of WO 2021 / 032590A1, about 25,000 liters (bulk) of heat-carrying particles are added to the reactor (300). An aqueous solution of 60 wt.% glucose (302) is fed into the reactor (300) at a rate of 23,000 kg / h (kilograms / hour). Steam as an atomizing gas (303) is fed into the reactor (300) at a rate of 1,380 kg / h. Steam in the fluidizing gas (301) is fed into the reactor (300) at a rate of 5,741 kg / h. The cooling step (309) involves cooling the cracked product to a cooling temperature of 230°C to 390°C. The separation step (310) involves separating solids from the cracked product cooled to the cooling temperature, wherein the solids include solids selected from the following: fluidizable heat-carrying particles, fragments of fluidizable heat-carrying particles, by-products from pyrolysis cracking of the feed solution, and mixtures thereof. The following carbon-based yields of major C2-C3 oxygenates were obtained from glucose: 57C-% ethanolaldehyde, 10C-% methylglyoxal, 4C-% acetol, 3C-% glyoxal and 10C-% formaldehyde.

[0300] The product gas flow rate at the reactor (300) outlet O' is about 24380 Nm 3 / h(Nm 3 It refers to standard cubic meters at a temperature of 0°C and an absolute pressure of 1 atmosphere. The production of other by-products (such as CO, CO2, acetic acid) may not significantly change this flow rate. It should be understood that, for example, changing the flow rate and / or composition of the atomizing gas (303) or the fluidizing gas (301) can change the resulting gas flow at the outlet O'. The process gas temperature at the outlet O' of the reactor (300) is about 525°C, and the cooling load required to cool the gas to a cooling temperature of 300°C is about 3.7 MW (megawatts). The reactor (300) is operated at an absolute pressure of about 2.1 atmospheres before the gas inlet of the particle separator (305).

[0301] Those skilled in the art will appreciate that the present invention can be scaled up as needed. The present invention is suitable for industrial scale production.

[0302] Various modifications and variations of the present invention that are obvious to those skilled in the art may be introduced without departing from the scope of the present invention. Although the present invention has been described in conjunction with specific preferred embodiments, it should be understood that the claimed invention should not be unduly limited to these specific embodiments. In fact, various modifications of the described modes for implementing the present invention that are obvious to those skilled in the art are intended to fall within the scope of the following claims.

Claims

1. A method for thermally cracking sugar into C1-C3 oxygen-containing compounds, the method comprising the following steps: a) providing an aqueous raw material solution containing sugar; b) providing a fluidized bed cracking reactor for pyrolytic cracking of sugars, wherein the fluidized bed cracking reactor comprises fluidizable heat-carrying particles; c) introducing the feedstock solution into a reactor to pyrolyze and crack the sugar to provide a cracked product comprising C1-C3 oxygen-containing compounds, wherein the temperature of the cracked product at the reactor outlet is at least 400° C.; d) cooling the cracked products downstream of the reactor to a cooling temperature of 230° C. to 390° C.; and e) separating solids from the cracked products cooled to the cooling temperature, wherein the solids comprise solids selected from the group consisting of fluidizable heat-carrying particles, fragments of fluidizable heat-carrying particles, by-products from pyrolytic cracking of a feedstock solution, and mixtures thereof.

2. The process according to claim 1, wherein step d) comprises cooling the cracked products to the cooling temperature indirectly, optionally wherein step d) comprises cooling the cracked products to the cooling temperature using a cooling device, optionally wherein the cooling device is a heat exchanger.

3. The process according to claim 1 or 2, wherein step d) is the earliest step of cooling the cracked products, optionally wherein the step of cooling the cracked products is not performed in the reactor, optionally wherein the step of cooling the cracked products is not performed before step d).

4. The method according to any one of claims 1 to 3, wherein the cooling temperature is 260 to 385°C, such as 270 to 380°C, 300 to 375°C or 330 to 370°C.

5. The process according to any one of claims 1 to 4, wherein the average residence time of the cracked product between step d) and step e) is not more than 50 s.

6. The process according to any one of claims 1 to 5, wherein the average residence time of the cracked products in step e) is from 8 s to 34 s.

7. The process according to any one of claims 1 to 6, wherein step e) comprises separating solids from the cracked products using a physical separation device.

8. A method according to claim 7, wherein the physical separation device is a filter, optionally wherein the filter has an efficiency of at least 99.9% for particles having a size of at least 50 microns, such as at least 30 microns, at least 20 microns or at least 10 microns, optionally wherein the filter is selected from bag filters and candle filters.

9. The method of claim 8, wherein the filter comprises a filter element having a filter surface, wherein the superficial velocity of the cracked products at the filter surface is from 0.1 to 3 cm / s.

10. The method according to any one of claims 1 to 9, wherein the sugar is a carbohydrate comprising one or more C6 sugar units and / or C5 sugar units, and / or wherein the sugar is a monosaccharide or a disaccharide, optionally wherein the sugar is selected from sucrose, lactose, xylose, arabinose, ribose, mannose, tagatose, galactose, glucose and fructose; and / or wherein the total content of sugars in the feed solution is 30 to 99 wt.%, e.g., 40 to 90 wt.%, or 50 to 80 wt.%, based on the total weight of the feed solution.

11. The process according to any one of claims 1 to 10, wherein the cracked product comprises glycolaldehyde; optionally wherein the cracked product comprises one, more or each of formaldehyde, glycolaldehyde, glyoxal, methylglyoxal and acetol; optionally wherein the cracked product comprises at least 10 wt.% glycolaldehyde based on the total weight of the cracked product.

12. The process according to any one of claims 1 to 11, wherein step d) is performed at a position below the position where the reactor is arranged.

13. The process according to any one of claims 1 to 12, wherein the pressure at the reactor outlet is at least 1.5 bara.

14. The process according to any one of claims 1 to 13, wherein the cracking reactor comprises a riser.

15. The method according to any one of claims 1 to 14, comprising one or more further separation steps between step c) and step d), wherein the separation between step c) and step d) or each separation comprises separating solids from the cracked products, wherein the solids comprise solids selected from the group consisting of fluidizable heat-carrying particles, fragments of fluidizable heat-carrying particles, by-products from pyrolytic cracking of a feed solution, and mixtures thereof, wherein the separation step between step c) and step d) or each separation step comprises separating at least 50 wt.% of solids from the cracked products based on the total weight of the solids.

16. A system for pyrolytic cracking of sugars into C1-C3 oxygenates, the system comprising: a) an aqueous raw material solution containing sugar; b) a fluidized bed cracking reactor configured to pyrolytically crack sugars and comprising fluidizable heat-carrying particles to provide cracked products comprising C1-C3 oxygenates, wherein the temperature of the cracked products at the reactor outlet is at least 400°C; c) means for cooling the cracked products downstream of the reactor to a cooling temperature of 230° C. to 390° C.; and d) a separation device configured to separate solids from the cracked products cooled to the cooling temperature, wherein the solids include solids selected from the group consisting of fluidizable heat-carrying particles, fragments of fluidizable heat-carrying particles, byproducts from pyrolytic cracking of the feed solution, and mixtures thereof.

17. The system according to claim 16, characterized in that It has the features of any one of claims 2 to 15.

18. A system for pyrolytic cracking of sugars into C1-C3 oxygenates, the system comprising: a) a fluidized bed cracking reactor configured to pyrolytically crack sugars to provide cracked products comprising C1-C3 oxygenates; and b) means for cooling the cracking products downstream of the reactor, The device for cooling the cracked products is arranged at a position below the reactor position.

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