Pyrolytic cracking of sugars

Abstract

The present invention relates to a process for the pyrolysis cracking of sugars to C1-C3 oxygenates, comprising the separation of solids from the cracked product wherein the temperature of the cracked product at the reactor outlet is at least 250 DEG C and wherein the water content is at least 40 vol.%, based on all gas phase components. The invention also relates to a system for 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 processes, pyrolysis, and different processes 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 cracking reactor for thermal cracking of sugars, wherein the fluidized bed cracking reactor comprises fluidizable heat-carrying particles;

[0013] c) introducing the feedstock solution into a reactor to pyrolytically crack the sugars to provide a cracked product comprising C1-C3 oxygenates;

[0014] d) separating solids from the cracked products, 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;

[0015] wherein the temperature of the cracked products at the reactor outlet is at least 250°C, such as at least 300°C, at least 350°C, at least 400°C or at least 450°C, and

[0016] The water content is at least 40 vol. %, based on all gas phase components.

[0017] According to another 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:

[0018] a) providing an aqueous raw material solution containing sugar;

[0019] b) providing a fluidized bed cracking reactor for thermal cracking of sugars, wherein the fluidized bed cracking reactor comprises fluidizable heat-carrying particles;

[0020] c) introducing the feedstock solution into a reactor to pyrolytically crack the sugars to provide a cracked product comprising C1-C3 oxygenates;

[0021] d) separating solids from the cracked products, 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;

[0022] wherein the temperature of the cracked products at the reactor outlet is at least 250°C, such as at least 300°C, at least 350°C, at least 400°C or at least 450°C, and

[0023] The steam partial pressure is greater than 650 mbar.

[0024] The present inventors have studied the method of improving the process and system for pyrolysis cracking of sugar into C1-C3 oxygen-containing compounds. Such process and system generally use fluidized bed cracking reactor to pyrolysis cracking of sugar to provide cracking products containing C1-C3 oxygen-containing compounds.

[0025] During such studies, the inventors discovered that there were problems with the operation of equipment downstream of the reactor. The inventors unexpectedly discovered that there was material adhering to the equipment. In some cases, this material could cause the equipment to block or clog.

[0026] Based on this discovery, the inventors conducted experiments to characterize the material and determined that the material comprises solids selected from the group consisting of fluidizable heat-carrying particles (delivered from a reactor), fragments of fluidizable heat-carrying particles (delivered from a reactor) and by-products from pyrolytic cracking of a feedstock solution, and mixtures thereof.

[0027] The inventors have tested various devices (e.g., physical separation devices, such as filters) to reduce the amount of solids delivered to the reactor downstream. Although these devices initially helped to achieve this, the inventors further discovered that over time (reactor run time), the amount of solids (e.g., "filter cake") deposited on these devices continued to increase. In order to promote efficient process operation, the solids are eventually removed. However, removing solids by replacing the device requires shutting down the process, resulting in a large amount of downtime, which is inefficient. When the device includes a filter, the inventors also attempted to remove solids from the filter by "back pulse" or "backflush" techniques, for example, which involves directing air in reverse through the filter. However, these techniques are not effective because the solids still adhere to the filter.

[0028] In view of the above problems, the present inventors unexpectedly found that the presence of water in an amount of at least 40 vol.% based on all gas phase components can improve the performance of the equipment downstream of the reactor. In particular, such a water content can reduce the blockage and / or clogging of the equipment downstream of the reactor. In addition, when a physical separation device (e.g., a filter arranged downstream of the reactor) is used, the present inventors unexpectedly also found that such a water content can reduce the accumulation of solids on the physical separation device.

[0029] Without being bound by theory, it is assumed that such a water content reduces the amount of solids delivered to the reactor downstream and / or reduces the tendency of solids to form and / or reduces the tendency of solids to block or clog equipment downstream of the reactor. In addition, when a physical separation device (e.g., a filter) disposed downstream of the reactor is used, it is further assumed that such a water content reduces the amount of solids reaching the physical separation device and / or reduces the tendency of solids to adhere to the physical separation device and / or reduces the tendency of solids to block or clog the physical separation device.

[0030] 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.

[0031] One skilled in the art can readily calculate the water content based on all gas phase components, for example by using input flow data.

[0032] a) Raw material solution

[0033] The method includes providing an aqueous raw material solution containing a sugar.

[0034] In one aspect, the total sugar content 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.

[0035] In one aspect, the total sugar content 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.

[0036] In one aspect, the total sugar content in the feed solution is 30 to 99 wt.%, eg, 40 to 90 wt.% or 50 to 80 wt.%, based on the total weight of the feed solution.

[0037] In one aspect, the feedstock solution is a liquid.

[0038] In one aspect, the water content in 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.

[0039] In one aspect, the water content in the feed 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 feed solution.

[0040] In one aspect, the total sugar content 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.

[0041] In one aspect, the sugar is a carbohydrate comprising one or more C6 sugar units and / or C5 sugar units.

[0042] In one aspect, the sugar is a monosaccharide or a disaccharide.

[0043] In one aspect, the sugar is selected from sucrose, lactose, xylose, arabinose, ribose, mannose, tagatose, galactose, glucose and fructose.

[0044] In one aspect, the feedstock solution can comprise a syrup.

[0045] In one aspect, the feedstock solution comprises more than one sugar.

[0046] Each sugar may independently be as described herein.

[0047] b) providing a fluidized bed cracking reactor for thermal cracking of sugar, wherein the fluidized bed cracking reactor comprises fluidizable heat-carrying particles

[0048] 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.

[0049] As will be appreciated by those skilled in the art, a fluidized bed reactor is a reactor that contains a bed of particles that can be fluidized by, for example, a fluidizing gas 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 can 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 can be determined or calculated by a skilled technician through experiments.

[0050] 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.

[0051] 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.

[0052] In one aspect, the reactor comprises a riser.

[0053] In one aspect, the riser extends vertically.

[0054] In one aspect, the riser (eg, the lower portion of the riser) includes a fluidizing gas inlet.

[0055] In one aspect, the riser (eg, a lower portion of the riser) includes a fluidizable particle inlet.

[0056] In one aspect, the riser (eg, the lower portion of the riser) includes a feedstock inlet.

[0057] In one aspect, the fluidizable particles inlet is disposed downstream of the fluidizing gas inlet.

[0058] In one aspect, the feedstock solution inlet is disposed downstream of the fluidizable particles inlet.

[0059] 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.

[0060] 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.

[0061] In one aspect, the feedstock solution inlet is disposed downstream of the fluidizable particles and the fluidizing gas inlet.

[0062] In one aspect, the method includes introducing fluidizable heat-carrying particles into a reactor.

[0063] In one aspect, the method includes introducing fluidizable particles into a reactor via a fluidizable particle inlet.

[0064] In one aspect, the method includes introducing fluidizable particles into a reactor via fluidizable particle and fluidizing gas inlets.

[0065] In one aspect, the temperature of the fluidizable heat-carrying particles within the reactor is at least 250°C, e.g., at least 300°C, at least 350°C, at least 400°C, at least 450°C, at least 500°C, at least 550°C, at least 600°C or at least 650°C.

[0066] 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.

[0067] 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, 450 to 650 °C, or 550 to 650 °C.

[0068] 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 250°C, e.g., at least 300°C, at least 350°C, at least 400°C, at least 450°C, at least 500°C, at least 550°C, at least 600°C or at least 650°C.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] In one aspect, the pressure at the reactor outlet is no greater than 8 bara, such as 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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 amount of heat to the feed solution. Fluidizable heat-carrying particles having a high heat capacity may require a lower mass flow rate than fluidizable heat-carrying particles having a lower heat capacity.

[0077] c) introducing the raw material solution into a reactor to thermally crack the sugar to provide a cracked product comprising C1-C3 oxygen-containing compounds

[0078] The method includes introducing a feedstock solution into a reactor to pyrolytically crack the sugars to provide a cracked product comprising C1-C3 oxygenates.

[0079] The pyrolytic cracking of sugars is an endothermic reaction, primarily due to the evaporation of any liquid in the feed solution.

[0080] In one aspect, the temperature difference of the fluidizable particles between the fluidizable particle inlet (or fluidizable particle and fluidizing gas inlet) and the fluidizable particle outlet of the cracking reactor is 10 to 600°C, eg, 50 to 250°C or 50 to 150°C.

[0081] 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.

[0082] 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.

[0083] Fluidizing gas

[0084] In one aspect, the method includes introducing a fluidizing gas into the reactor.

[0085] As will be appreciated by those skilled in the art, the fluidizing gas fluidizes the fluidizable heat-carrying particles in the reactor.

[0086] In one aspect, the method includes introducing a fluidizing gas into the reactor via a fluidizing gas inlet.

[0087] In one aspect, the method includes introducing a fluidizing gas into a reactor via fluidizable particles and a fluidizing gas inlet.

[0088] 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.

[0089] 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.

[0090] In one aspect, in step c), the feedstock solution is entrained in the fluidizing gas.

[0091] In one aspect, the fluidizing gas comprises water (eg, steam).

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

[0093] In one aspect, the fluidizing gas consists of water (eg, steam).

[0094] In this document, "water" and "steam" are used interchangeably.

[0095] In one aspect, the water content in the fluidizing gas is at least 50 wt.%, e.g., at least 60 wt.%, at least 70 wt.%, at least 75 wt.%, at least 80 wt.%, at least 85 wt.%, at least 90 wt.%, at least 95 wt.% or at least 99 wt.%, based on the total weight of the fluidizing gas.

[0096] In one aspect, the water content of the fluidizing gas is no greater than 90 wt.%, eg, no greater than 95 wt.%, no greater than 99 wt.%, or no greater than 99.5 wt.%, based on the total weight of the fluidizing gas.

[0097] 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.

[0098] 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.

[0099] Atomizing gas

[0100] In one aspect, the method includes introducing an atomizing gas into the reactor.

[0101] 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.

[0102] 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.

[0103] In one aspect, the atomizing gas comprises water (eg, steam).

[0104] In one aspect, the atomizing gas consists essentially of water (eg, steam).

[0105] In one aspect, the atomizing gas consists of water (eg, steam).

[0106] In one aspect, the water content in the atomizing gas is at least 50 wt.%, e.g., at least 60 wt.%, at least 70 wt.%, at least 75 wt.%, at least 80 wt.%, at least 85 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 99 wt.%, based on the total weight of the atomizing gas.

[0107] In one aspect, the water content of the atomizing gas is no greater than 90 wt.%, eg, no greater than 95 wt.%, no greater than 99 wt.%, or no greater than 99.5 wt.%, based on the total weight of the atomizing gas.

[0108] 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.

[0109] 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.

[0110] Introduced water

[0111] The method includes introducing water into a reactor.

[0112] 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.

[0113] In one aspect, water is introduced into the reactor via the fluidizing gas.

[0114] In one aspect, water is introduced into the reactor via an atomizing gas.

[0115] In one aspect, the mass ratio of the total amount of sugar introduced into the reactor to the total amount of water introduced into the reactor is at least 0.1:1, e.g., at least 0.2:1, at least 0.3:1, at least 0.4:1, at least 0.45:1, at least 0.5:1, at least 0.55:1, at least 0.6:1, at least 0.65:1, at least 0.7:1, at least 0.75:1, at least 0.8:1, at least 0.85:1, at least 0.9:1, or at least 0.95:1.

[0116] In one aspect, the mass ratio of the total amount of sugar introduced into the reactor to the total amount of water introduced into the reactor is no greater than 5:1, e.g., no greater than 4:1, no greater than 3.5:1, no greater than 3:1, no greater than 2.5:1, no greater than 2:1, no greater than 1.5:1, no greater than 1.4:1, no greater than 1.3:1, no greater than 1.25:1, no greater than 1.2:1, no greater than 1.15:1, no greater than 1.1:1, no greater than 1.05:1 or no greater than 1:1.

[0117] In one aspect, the mass ratio of the total amount of sugar introduced into the reactor to the total amount of water introduced into the reactor is from 0.2: 1 to 5: 1, e.g., from 0.25: 1 to 4: 1, from 0.25: 1 to 3.5: 1, from 0.25: 1 to 2.2: 1, from 0.3: 1 to 1.8: 1, from 0.4: 1 to 1.75: 1, from 0.55: 1 to 1.5: 1, from 0.6: 1 to 1.3: 1, from 0.65: 1 to 1.2: 1, from 0.7: 1 to 1: 1, or from 0.75: 1 to 0.90: 1.

[0118] In one aspect, the mass ratio of water introduced into the reactor via the feed solution to the total amount of water introduced into the reactor is at least 0.001:1, e.g., at least 0.005:1, at least 0.01:1, at least 0.02:1, at least 0.04:1, at least 0.05:1, at least 0.1:1, at least 0.15:1, at least 0.2:1, at least 0.25:1, or at least 0.3:1.

[0119] In one aspect, the mass ratio of water introduced into the reactor via the feed solution to the total amount of water introduced into the reactor is not greater than 5:1, e.g., not greater than 4:1, not greater than 3:1, not greater than 2:1, not greater than 1:1, not greater than 0.8:1, not greater than 0.6:1, not greater than 0.55:1, not greater than 0.5:1, not greater than 0.45:1, or not greater than 0.4:1.

[0120] In one aspect, the mass ratio of water introduced into the reactor via the feed solution to the total amount of water introduced into the reactor is 0.2:1 to 3:1, e.g., 0.04:1 to 4:1, 0.05:1 to 2:1, 0.1 to 1:1, 0.15:1 to 0.6:1, 0.2:1 to 0.5:1, 0.25:1 to 0.45:1, or 0.3:1 to 0.4:1.

[0121] Cracking products

[0122] 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.

[0123] In one aspect, in step c), the cracked product is a solid dense cracked product.

[0124] In one aspect, the solid dense cracked products comprise C1-C3 oxygenates and solids.

[0125] In one aspect, step d) comprises separating solids from solid dense cracked products to provide solids-depleted 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.

[0126] In one aspect, the solids-lean cracked product comprises C1-C3 oxygenates.

[0127] In one aspect, the solids-depleted cracked product contains a smaller amount of solids than the solids-dense cracked product.

[0128] In this document, the terms "lean" in "solids-lean" and "dense" in "solids-dense" are relative to each other.

[0129] 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.

[0130] 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.

[0131] In one aspect, the cracking product comprises glycolaldehyde.

[0132] In one aspect, the cracking products include glycolaldehyde in a major portion.

[0133] 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.

[0134] 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.

[0135] In one aspect, the cracked product comprises one or more of 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.

[0136] 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.

[0137] 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).

[0138] In one aspect, "based on the total weight of cracked products" refers to the cracked products after step (d) (eg, solids-depleted cracked products).

[0139] In one aspect, "based on the total weight of the cracked products" refers to the cracked products excluding solids.

[0140] Water content (vol.%)

[0141] In one aspect, the water content is based on all gas phase components at the reactor outlet.

[0142] In one aspect, the water content is based on all gas phase components within the reactor.

[0143] In one aspect, the water content is measured (eg, using a suitable instrument). One skilled in the art will be aware of suitable instruments for measuring water content.

[0144] In one aspect, the water content is calculated (eg, theoretically determined). Suitable methods for calculating water content are known to those skilled in the art.

[0145] As explained below in "d) Separating solids from cracked products", in one aspect, step d) comprises separating solids from cracked products using a physical separation device.

[0146] In one aspect, when a physical separation device (eg, a filter) is used, the water content is based on all gas phase components at the inlet of the physical separation device (eg, filter).

[0147] In one aspect, the water content is at least 45 vol.%, e.g., at least 50 vol.%, at least 55 vol.%, at least 60 vol.%, at least 65 vol.%, at least 70 vol.%, at least 75 vol.%, or at least 80 vol.%, based on all gas phase components.

[0148] In one aspect, the water content at the reactor outlet is at least 45 vol.%, e.g., at least 50 vol.%, at least 55 vol.%, at least 60 vol.%, at least 65 vol.%, at least 70 vol.%, at least 75 vol.% or at least 80 vol.%, based on all gas phase components at the reactor outlet.

[0149] In one aspect, the water content in the reactor is at least 45 vol.%, e.g., at least 50 vol.%, at least 55 vol.%, at least 60 vol.%, at least 65 vol.%, at least 70 vol.%, at least 75 vol.% or at least 80 vol.%, based on all gas phase components in the reactor.

[0150] In one aspect, the water content at the inlet of the physical separation device (e.g., a filter) is at least 45 vol.%, e.g., at least 50 vol.%, at least 55 vol.%, at least 60 vol.%, at least 65 vol.%, at least 70 vol.%, at least 75 vol.%, or at least 80 vol.%, based on all gas phase components at the inlet of the physical separation device.

[0151] In one aspect, the water content is no greater than 99 vol.%, eg, no greater than 95 vol.%, no greater than 90 vol.%, no greater than 85 vol.%, or no greater than 80 vol.%, based on all gas phase components.

[0152] In one aspect, the water content at the reactor outlet is no greater than 99 vol.%, eg, no greater than 95 vol.%, no greater than 90 vol.%, no greater than 85 vol.% or no greater than 80 vol.%, based on all gas phase components at the reactor outlet.

[0153] In one aspect, the water content in the reactor is no greater than 99 vol.%, such as no greater than 95 vol.%, no greater than 90 vol.%, no greater than 85 vol.% or no greater than 80 vol.%, based on all gas phase components in the reactor.

[0154] In one aspect, the water content at the inlet of the physical separation device (e.g., filter) is no more than 99 vol.%, e.g., no more than 95 vol.%, no more than 90 vol.%, no more than 85 vol.% or no more than 80 vol.%, based on all gas phase components at the inlet of the physical separation device.

[0155] In one aspect, the water content is 45 to 99.5 vol.%, eg, 50 to 99 vol.%, 55 to 97.5 vol.%, 60 to 92.5 vol.%, 65 to 90 vol.%, 70 to 87.5 vol.% or 75 to 85 vol.%, based on all gas phase components.

[0156] In one aspect, the water content at the reactor outlet is 45 to 99.5 vol.%, e.g., 50 to 99 vol.%, 55 to 97.5 vol.%, 60 to 92.5 vol.%, 65 to 90 vol.%, 70 to 87.5 vol.% or 75 to 85 vol.%, based on all gas phase components at the reactor outlet.

[0157] In one aspect, the water content in the reactor is 45 to 99.5 vol.%, e.g., 50 to 99 vol.%, 55 to 97.5 vol.%, 60 to 92.5 vol.%, 65 to 90 vol.%, 70 to 87.5 vol.% or 75 to 85 vol.%, based on all gas phase components in the reactor.

[0158] In one aspect, the water content at the inlet of the physical separation device (e.g., a filter) is 45 to 99.5 vol.%, e.g., 50 to 99 vol.%, 55 to 97.5 vol.%, 60 to 92.5 vol.%, 65 to 90 vol.%, 70 to 87.5 vol.%, or 75 to 85 vol.%, based on all gas phase components at the inlet of the physical separation device.

[0159] Partial Pressure

[0160] In one aspect, the partial pressure of steam is greater than 650 mbar.

[0161] The inventors have also found that the presence of steam at a partial pressure greater than 650 mbar helps to reduce the amount of such solids transported downstream of the reactor, thereby reducing the negative impact on the equipment.

[0162] In one aspect, the partial pressure of steam is at the outlet of the reactor.

[0163] In one aspect, the partial pressure of steam is within the reactor.

[0164] In one aspect, when a physical separation device (eg, a filter) is used, the partial pressure is located at the physical separation device (eg, an inlet thereof).

[0165] Those skilled in the art will appreciate that the partial pressure of a gas can be defined by the following formula:

[0166] p i =x i ×p

[0167] Among them, p i is the partial pressure of a component in the gas mixture, x i is the volume fraction of the component in the gas mixture, and p is the total pressure of the gas mixture.

[0168] In one aspect, the partial pressure is measured (eg, using a suitable instrument). One skilled in the art will be aware of suitable instruments for measuring partial pressure.

[0169] In one aspect, the partial pressure is calculated (eg, determined theoretically). One skilled in the art will be aware of suitable methods for calculating partial pressure.

[0170] In one aspect, the partial pressure of steam is at least 700 mbar, e.g., at least 750 mbar, at least 800 mbar, at least 850 mbar, at least 900 mbar, at least 950 mbar, at least 1000 mbar, at least 1050 mbar, at least 1100 mbar, at least 1150 mbar, at least 1200 mbar, at least 1250 mbar, at least 1300 mbar, at least 1350 mbar, at least 1400 mbar, at least 1500 mbar, at least 1600 mbar, at least 1700 mbar, at least 1800 mbar, at least 1900 mbar, at least 2000 mbar, at least 2100 mbar, at least 2200 mbar, at least 2300 mbar, at least 2400 mbar, at least 2500 mbar, at least 2600 mbar, at least 2700 mbar, at least 2800 mbar, at least 2900 mbar, at least 3000 mbar, at least 3100 mbar, at least 3200 mbar, at least 3300 mbar, at least 3400 mbar, at least 3500 mbar, at least 3600 mbar, at least 3700 mbar, at least 3800 mbar, at least 3900 mbar, at least 4000 mbar, at least 4100 mbar, at least 4200 mbar, at least 4300 mbar, at least 4400 mbar, at least 4500 mbar, at least 4600 mbar, at least 4700 mbar, at least 4800 mbar, at least 4900 mbar, at least At least 1450 mbar, at least 1500 mbar, at least 1550 mbar, at least 1600 mbar, at least 1650 mbar, at least 1700 mbar, at least 1750 mbar, at least 1800 mbar, at least 1850 mbar, at least 1900 mbar, at least 1950 mbar, at least 2000 mbar, at least 2050 mbar, at least 2100 mbar, at least 2150 mbar or at least 2200 mbar.

[0171] In one aspect, the steam partial pressure at the reactor outlet is greater than 650 mbar. In one aspect, the steam partial pressure at the reactor outlet is at least 700 mbar, e.g., at least 750 mbar, at least 800 mbar, at least 850 mbar, at least 900 mbar, at least 950 mbar, at least 1000 mbar, at least 1050 mbar, at least 1100 mbar, at least 1150 mbar, at least 1200 mbar, at least 1250 mbar, at least 1300 mbar, at least 1350 mbar, at least 1400 mbar, at least 1450 mbar, at least 1500 mbar, at least 1550 mbar, at least 1600 mbar, at least 1650 mbar, at least 1700 mbar, at least 1750 mbar, at least 1800 mbar, at least 1900 mbar, at least 1950 mbar, at least 2000 mbar, at least 2050 mbar, at least 2100 mbar, at least 2150 mbar, or at least 2200 mbar.

[0172] In one aspect, the steam partial pressure in the reactor is greater than 650 mbar. In one aspect, the steam partial pressure in the reactor is at least 700 mbar, such as at least 750 mbar, at least 800 mbar, at least 850 mbar, at least 900 mbar, at least 950 mbar, at least 1000 mbar, at least 1050 mbar, at least 1100 mbar, at least 1150 mbar, at least 1200 mbar, at least 1250 mbar, at least 1300 mbar, at least 1350 mbar, at least 1400 mbar. , at least 1450 mbar, at least 1500 mbar, at least 1550 mbar, at least 1600 mbar, at least 1650 mbar, at least 1700 mbar, at least 1750 mbar, at least 1800 mbar, at least 1850 mbar, at least 1900 mbar, at least 1950 mbar, at least 2000 mbar, at least 2050 mbar, at least 2100 mbar, at least 2150 mbar or at least 2200 mbar.

[0173] In one aspect, the steam partial pressure at the inlet of the physical separation device (e.g., filter) is greater than 650 mbar. In one aspect, the steam partial pressure at the inlet of the physical separation device (e.g., filter) is at least 700 mbar, for example, at least 750 mbar, at least 800 mbar, at least 850 mbar, at least 900 mbar, at least 950 mbar, at least 1000 mbar, at least 1050 mbar, at least 1100 mbar, at least 1150 mbar, at least 1200 mbar, at least 1250 mbar, at least 1300 mbar, at least 1350 mbar, at least 1400 mbar, at least 1450 mbar, at least 150 ... 1900 mbar, at least 1950 mbar, at least 2000 mbar, at least 2050 mbar, at least 2100 mbar, at least 2150 mbar or at least 2200 mbar.

[0174] In one aspect, the partial pressure of steam is no greater than 5000 mbar, e.g., no greater than 4500 mbar, no greater than 4000 mbar, no greater than 3800 mbar, no greater than 3600 mbar, no greater than 3400 mbar, no greater than 3200 mbar, no greater than 3000 mbar, no greater than 2800 mbar, no greater than 2600 mbar, or no greater than 2500 mbar.

[0175] In one aspect, the steam partial pressure at the reactor outlet is no greater than 5000 mbar, e.g., no greater than 4500 mbar, no greater than 4000 mbar, no greater than 3800 mbar, no greater than 3600 mbar, no greater than 3400 mbar, no greater than 3200 mbar, no greater than 3000 mbar, no greater than 2800 mbar, no greater than 2600 mbar, or no greater than 2500 mbar.

[0176] In one aspect, the steam partial pressure in the reactor is no greater than 5000 mbar, e.g., no greater than 4500 mbar, no greater than 4000 mbar, no greater than 3800 mbar, no greater than 3600 mbar, no greater than 3400 mbar, no greater than 3200 mbar, no greater than 3000 mbar, no greater than 2800 mbar, no greater than 2600 mbar, or no greater than 2500 mbar.

[0177] In one aspect, the steam partial pressure at the inlet of the physical separation device (e.g., filter) is no greater than 5000 mbar, e.g., no greater than 4500 mbar, no greater than 4000 mbar, no greater than 3800 mbar, no greater than 3600 mbar, no greater than 3400 mbar, no greater than 3200 mbar, no greater than 3000 mbar, no greater than 2800 mbar, no greater than 2600 mbar, or no greater than 2500 mbar.

[0178] In one aspect, the partial pressure of steam is 700 to 5000 mbar, e.g., 750 to 4000 mbar, 800 to 3500 mbar, 1000 to 3000 mbar, 1200 to 2800 mbar, 1500 to 2700 mbar, or 2000 to 2500 mbar.

[0179] In one aspect, the steam partial pressure at the reactor outlet is 700 to 5000 mbar, e.g., 750 to 4000 mbar, 800 to 3500 mbar, 1000 to 3000 mbar, 1200 to 2800 mbar, 1500 to 2700 mbar, or 2000 to 2500 mbar.

[0180] In one aspect, the steam partial pressure within the reactor is 700 to 5000 mbar, e.g., 750 to 4000 mbar, 800 to 3500 mbar, 1000 to 3000 mbar, 1200 to 2800 mbar, 1500 to 2700 mbar, or 2000 to 2500 mbar.

[0181] In one aspect, the steam partial pressure at the inlet of the physical separation device (e.g., filter) is 700 to 5000 mbar, e.g., 750 to 4000 mbar, 800 to 3500 mbar, 1000 to 3000 mbar, 1200 to 2800 mbar, 1500 to 2700 mbar, or 2000 to 2500 mbar.

[0182] d) Separation of solids from cracked products

[0183] The method includes separating solids from cracked products, wherein the solids include solids selected from the group consisting of fluidizable particles, fragments of fluidizable particles, byproducts from pyrolytic cracking of a feedstock solution, and mixtures thereof.

[0184] In one aspect, 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.% solids from the cracked products based on the total weight of the solids.

[0185] In one aspect, step d) 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 based on the total weight of the solids.

[0186] In one aspect, step d) comprises separating a major portion of solids from the cracked products.

[0187] In one aspect, 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.% solids from the cracked products based on the total weight of the solids.

[0188] In one aspect, step d) comprises separating substantially all of the solids from the cracked products.

[0189] In one aspect, step d) comprises separating the solids from the cracked products using a physical separation device.

[0190] In one aspect, the physical separation device is a particle separator.

[0191] In one aspect, the physical separation device is a low capacity separator.

[0192] In one aspect, the physical separation device is a change-of-direction separator.

[0193] In one aspect, the physical separation device is a cyclone separator.

[0194] In one aspect, the physical separation device is a filter.

[0195] In one aspect, the filter is selected from the group consisting of: a metal filter and a ceramic filter.

[0196] 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.

[0197] 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.

[0198] In one aspect, the filter element comprises a porous matrix.

[0199] 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.

[0200] 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.

[0201] In one aspect, the filter comprises a plurality of filter elements. Each filter element can be independently as described herein.

[0202] In one aspect, the filter is a candle filter.

[0203] In one aspect, the filter is a bag filter.

[0204] In one aspect, step d) occurs downstream of the reactor.

[0205] In one aspect, the physical separation device is arranged downstream of the reactor.

[0206] In one aspect, multiple physical separation devices are used. Each physical separation device can independently be as described herein.

[0207] In one aspect, step d) comprises filtering the cracked product using a filter.

[0208] In one aspect, the temperature at the filter inlet is from 230 to 390°C, or from 270 to 390°C, or from 300 to 380°C, or from 330 to 370°C.

[0209] 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. Filter efficiency can be measured using ASTM 795 ACFTD.

[0210] In one aspect, the process is suitable for industrial-scale production of C1-C3 oxygenates.

[0211] solid

[0212] The solid includes a solid selected from the group consisting of fluidizable heat-carrying particles, fragments of fluidizable heat-carrying particles, by-products from pyrolysis and cracking of a feedstock solution, and mixtures thereof.

[0213] 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.

[0214] 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.

[0215] 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.

[0216] 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.

[0217] 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.

[0218] 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.

[0219] 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.

[0220] In one aspect, the pyrolytic cracking process is operated as a continuous process.

[0221] Further process steps

[0222] 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.

[0223] 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 solids from the cracked product based on the total weight of the solids.

[0224] 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.

[0225] 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.

[0226] 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.

[0227] 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.% solids from the cracked products based on the total weight of the solids.

[0228] 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.% solids from the cracked product based on the total weight of the solids.

[0229] 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.

[0230] 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.% solids from the cracked products based on the total weight of the solids.

[0231] 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.% solids from the cracked product based on the total weight of the solids.

[0232] 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).

[0233] 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:

[0234] a) an aqueous raw material solution comprising sugar;

[0235] 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;

[0236] c) a separation device configured to separate solids from the cracked products, 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 feedstock solution, and mixtures thereof;

[0237] wherein the temperature of the cracked products at the reactor outlet is at least 250°C, such as at least 300°C, at least 350°C, at least 400°C or at least 450°C, and

[0238] The water content is at least 40 vol.% based on all gas phase components.

[0239] 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:

[0240] a) an aqueous raw material solution comprising sugar;

[0241] 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;

[0242] c) a separation device configured to separate solids from the cracked products, 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 feedstock solution, and mixtures thereof;

[0243] wherein the temperature of the cracked products at the reactor outlet is at least 250°C, such as at least 300°C, at least 350°C, at least 400°C or at least 450°C, and

[0244] The steam partial pressure is greater than 650 mbar.

[0245] 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.

[0246] BRIEF DESCRIPTION OF THE DRAWINGS

[0247] 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.

[0248] 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;

[0249] Figure 2 Shows Figure 1 A top view of the intermediate cracking reactor;

[0250] Figure 3shows a cross-sectional side view of a reheater forming part of a system according to one embodiment of the present invention;

[0251] 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;

[0252] 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);

[0253] Figure 6 shows the variation of pressure drop across the filter of a system according to one embodiment of the present invention;

[0254] Figure 7 is a schematic diagram of a candle filter; and

[0255] Figure 8 A schematic diagram of a cracking reactor forming part of a system according to one embodiment of the present invention is shown.

[0256] Position number

[0257] 1. Cracking reactor

[0258] 2. Cracking riser

[0259] 3. First particle separator

[0260] 4. Second particle separator

[0261] 5. Cooling section

[0262] 6. Primary fluidizing gas inlet

[0263] 7. Fluidizable particle inlet

[0264] 8. Raw material and atomizing gas inlet

[0265] 9. Product export

[0266] 10. Fluidizable particle outlet

[0267] 11. Reheater

[0268] 12. Fuel and combustion air inlet

[0269] 13. Combustion Chamber

[0270] 14. Reheater fluidizable particle inlet

[0271] 15. Reheater riser

[0272] 16. Reheater fluidized particle separator

[0273] 17. Reheater fluidized particle outlet

[0274] 18. Reheater gas outlet

[0275] 19. Second reheater fluidized particle separator

[0276] 20. Stripper

[0277] 21. Secondary fluidizing gas inlet

[0278] 22. Secondary reheater fluidizing and stripping gas inlet

[0279] O'. Reactor outlet

[0280] 100.Heat exchanger

[0281] 200. Physical separation devices (e.g. filters) for gas / solid filtration

[0282] 300. Cracking reactor

[0283] 301. Fluidizing gas

[0284] 302. Raw material solution

[0285] 303. Atomized gas

[0286] 304. Raw material and atomizing gas inlet (feed nozzle)

[0287] 305.First particle separator

[0288] 306. Recirculating heat-carrying particles

[0289] 307. Rough dividing line used to distinguish dense phase from lean phase

[0290] 308.Heating device DETAILED DESCRIPTION OF THE INVENTION

[0292] 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 that the fluidizable heat-carrying particles have 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 fluidizable heat-carrying particles is also provided. The reactor 01 further includes an outlet O'. It should be understood that in use, the cracked product leaves the reactor 01 at the outlet O' for further processing and / or collection.

[0293] 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.

[0294] 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.

[0295] 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.

[0296] exist Figure 1 and Figure 2 In the embodiment shown, the first particle separator 03 comprises outlet pipes which change the direction of the outlet flow from the riser 02 by approximately 180° 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.

[0297] exist Figure 4 In the embodiment shown, the first particle separator 03 induces separation of gas and particles, forcing the riser gas and the solids entering the reactor 1 to be discharged tangentially 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.

[0298] 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.

[0299] 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 .

[0300] Cracked products are extracted from the cracking reactor 01 via the product outlet 09 .

[0301] exist Figure 1 and Figure 4 In the embodiment shown, an optional further second particle separator 04 is provided for separating a further portion of the fluidizable particles from the product stream before extracting the cracked products.

[0302] 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.

[0303] 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.

[0304] 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 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. A 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.

[0305] 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. Figure 1-4In the embodiment of the invention, it is also conceivable to strip the product gas (cracked products) before or after the fluidizable particle outlet 10, but this is not shown in the figure.

[0306] 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 cooling steps or other unit operations.

[0307] exist Figure 5 In the embodiment of the present invention, the product gas passes through the product outlet 9 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).

[0308] 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.

[0309] In other embodiments, other physical separation devices and other filters are contemplated. For example, candle filters are described in Gasification (Higman, C., 2nd edition, 2008, p. 224-225). The function and operation of candle filters are known to those skilled in the art and are therefore not described in further detail here.

[0310] In use, the cracked products leave the reactor 01 via the product outlet 09 , flow through the heat exchanger 100 and then pass through the separation device 200 .

[0311] The inventor unexpectedly found that there was a substance adhering to the downstream equipment of the reactor 01. In some cases, this substance caused the equipment to be blocked or clogged. The inventor conducted experiments to characterize the substance and determined that this substance included solids selected from the following: fluidizable heat-carrying particles (transported from the reactor 01), fragments of fluidizable heat-carrying particles (transported from the reactor 01), by-products from the pyrolysis and cracking of the raw material solution, and mixtures thereof. The inventor tested various devices (e.g., physical separation devices 200, such as filters) to reduce the amount of solids transported to the downstream of the reactor 01. Although these devices initially helped to achieve this, the inventor further found that the amount of solids (e.g., "filter cakes") deposited on these devices increased over time (reactor operation time). In order to promote efficient process operation, the solids are eventually removed. However, removing solids by replacing the device requires shutting down the process, resulting in a large amount of downtime and low efficiency. When the device includes a filter 200, the inventor also tried to remove solids from the filter 200 by "reverse pulse" or "reverse purge" technology, for example, this involves guiding air in the opposite direction through the filter 200. However, these techniques are not effective because the solids still adhere to the filter 200 .

[0312] In view of the above problems, the present inventors unexpectedly found that the presence of water in an amount of at least 40 vol.% based on all gas phase components can improve the performance of the equipment downstream of the reactor 01. Specifically, such a water content can reduce the clogging and / or plugging of the equipment downstream of the reactor 01. In addition, when a physical separation device (e.g., filter 200) arranged downstream of the reactor 01 is used, the present inventors unexpectedly also found that such a water content reduces the accumulation of solids on the physical separation device 01.

[0313] Without being bound by theory, it is assumed that such water content reduces the amount of solids delivered to the downstream of the reactor 01 and / or reduces the tendency of solids to form and / or reduces the tendency of solids to block or plug equipment downstream of the reactor 01. In addition, when a physical separation device (e.g., filter 200) arranged downstream of the reactor is used, it is further assumed that such water content reduces the amount of solids reaching the physical separation device 200 and / or reduces the tendency of solids to adhere to the physical separation device 200 and / or reduces the tendency of solids to block or plug the physical separation device 200.

[0314] For example, in an embodiment including a filter 200 disposed downstream of reactor 01, the use of steam instead of nitrogen (e.g., provided as an atomizing gas through inlet 8 and / or provided as a fluidizing gas through inlets 6, 21) can have a surprisingly beneficial effect on the filter pressure drop observed during operation. That is, water can be used to maintain a more stable pressure drop across filter 23 during operation. In contrast, when nitrogen or, in fact, low concentrations of water are used, the observed filter pressure drop gradually increases during operation. The beneficial effect on the observed pressure drop indicates that the amount of solids transported downstream of reactor 1 and collected on filter 200 is reduced. As a result, the process can be run for a longer period of time before filter 200 needs to be replaced.

[0315] 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.

[0316] Example 1: Effect of water content on filter pressure drop

[0317] In a system according to one embodiment of the present invention, an aqueous feedstock solution comprising about 60 wt.% glucose and 40 wt.% water (based on the total weight of the feedstock solution) is subjected to thermal cracking (i.e. Figure 4 and 5 ). This involves introducing the feed solution into reactor 01 at position 8 at a (liquid) feed rate of 30 kg / hour. Cracking is carried out under the following conditions:

[0318] (A) Immediately before the first particle separator (3), the water content is 35-40 vol.% based on all gas phase components; at the outlet O' of the reactor 01, the water content is 25-30 vol.% based on all gas phase components (steam partial pressure is 880 to 1030 mbar). The reactor is a riser reactor 01 with a length of about 3 meters. After evaporation and cracking of the raw material solution, the apparent gas velocity is about 6 m / s. The raw material solution is injected into the reactor 1 and enters the bottom of the riser 02 by using a gas-assisted internal mixing atomizing nozzle (i.e., the raw material and atomizing gas inlet 08), and the atomizing gas flow rate is 15 kg / h nitrogen. The optional cooling step 05 is omitted.

[0319] (B) Immediately before the first particle separator (3), the water content is 80-81 vol.% based on all gas phase components; at the outlet O' of the reactor 01, the water content is 85-90 vol.% based on all gas phase components (steam partial pressure is 2040 mbar). The reactor is a riser reactor 01 with a length of about 3 meters. After evaporation and cracking of the raw material solution, the apparent gas velocity is about 6 meters per second. The raw material solution is injected into the reactor 1 and enters the bottom of the riser 02 by using a gas-assisted internal mixing atomizing nozzle (i.e., the raw material and atomizing gas inlet 08), and the atomizing gas flow rate is 12 kg / h steam. The optional cooling step 05 is started from 15 hours to 25 hours of operation, and the product gas is cooled by about 50°C.

[0320] For (A), nitrogen was introduced into the reactor via: fluidizing inlet 6, with a flow rate of 8.7 kg / h nitrogen; feed and atomizing gas inlet 8 (i.e., added as atomizing gas together with the feed solution, as described above); and fluidizing gas inlet 21, with a flow rate of 15 kg / h nitrogen. The total pressure measured at outlet O' of reactor 01 was about 2.4 bara (absolute pressure). The temperature of the fluidizable heat-carrying particles at inlet 07 was about 570°C, and the temperature at reactor outlet O' was about 475°C. The temperature at the inlet of filter 200 was about 400°C.

[0321] For (B), water was introduced into the reactor via: fluidizing inlet 6, gas flow rate 7 kg / h steam; feed and atomizing gas inlet 8 (i.e. added as atomizing gas together with the feed solution, as described above); and fluidizing gas inlet 21, flow rate 12 kg / h steam. The total pressure measured at outlet O' of reactor 01 was about 2.4 bara (absolute pressure). The temperature of the fluidizable heat-carrying particles at inlet 07 was about 570°C, and the temperature at reactor outlet O' was about 475°C. The temperature at the inlet of filter 200 was about 400°C.

[0322] For (B), the mass ratio of the total amount of sugar introduced into the reactor 01 to the total amount of water introduced into the reactor was 0.41:1.

[0323] In both cases, the volume-based gas flow rates in the system are similar, providing the same superficial gas velocity and residence time in different parts of the system.

[0324] Figure 6 The pressure drop changes measured on the filter 200 during operation (A) and (B) are shown, wherein (A) represents data points with crosses and (B) represents data points with circles. The water content at the outlet O' of the reactor 01 is calculated using the flow rate data of the input flow of the reactor 01. Those skilled in the art can easily perform this calculation.

[0325] from Figure 6 As can be seen from Figure 2, for (A), the pressure drop across the filter 200 increases steadily over time at a rate of about 0.27 mbar / hour. Figure 6 It can also be seen that for (B), the pressure drop across the filter 200 remains approximately constant (rate of change is about 0 mbar / hour). This is a performance parameter that is significantly improved for industrial long-term operation. At about 15 hours, a slight change in the pressure drop of (B) was measured, which is caused by an increase in water content from 80 vol.% to 81 vol.% (based on all gas phase components before the first particle separator (3)) and a higher gas flow rate.

[0326] It will be appreciated that the filter pressure drop also varies with the following filtration parameters, such as the surface area of ​​the filter 200 (in this example, 3.4 m2 at the gas inlet surface of the filter). 2 ), the properties of the gas flow (e.g., flow rate and composition), and the thickness of the filter cake (containing solids) deposited on the filter 200. For example, increasing the surface area of ​​the filter or reducing the gas flow rate can reduce the rate of increase of the pressure drop during operation. It should also be understood that the reactor may be operated in another unintended mode, thereby producing more cracked by-products. Those skilled in the art will know how to control the effects of commonly known filtering parameters.

[0327] This example demonstrates that an increase in water content (e.g., at outlet O' of reactor 01) reduces the amount of solids transported downstream of the reactor and collected on separation device 200. Without being bound by theory, it is believed that such water content can reduce the deposition rate of solids on separation device 200 and / or increase the desorption rate of solids from separation device 200. For example, the water content may reach a level such that the net accumulation of solids on separation device 200 (i.e., deposition rate minus desorption rate) may be reduced relative to when a lower water content is used.

[0328] In each of the cases (A) and (B), a solid-poor cracked product is obtained after filtering through the filter 200. The solid-poor cracked product contains substantially no solids.

[0329] In each case of (A) and (B), after filtering through filter 200, the cracked product (lean solids) stream is condensed in a cooling tower together with the recycled condensed product liquid. The glycolaldehyde concentration of the condensed product (lean solids) is measured by HPLC, and a mass (or carbon) balance is applied to derive the carbon-based glycolaldehyde yield in the pyrolytic cracking, i.e., the percentage of carbon recovered as carbon in glycolaldehyde in the feed solution. For example, the glycolaldehyde concentration of the condensed product (lean solids) can be calculated according to the following formula:

[0330] Glycolaldehyde carbon yield = 100% * (2 * mc * Cc / (MwGA * DensC)) / (6 * m1 * C1 / MwGlu)

[0331] in:

[0332] mc is the mass flow rate measured after the condensation step, in kg / h

[0333] Cc is the concentration of glycolaldehyde measured after the condensation step, in kg / m 3

[0334] MwGA is the molecular weight of glycolaldehyde in kg / mol

[0335] DensC is the density of the condensed product in kg / m 3

[0336] m1 is the feed rate of the raw material solution entering the reactor 01, in kg / h

[0337] C1 is the glucose concentration in wt.%

[0338] MwGlu is the molecular weight of glucose in kg / mol

[0339] For (A), the obtained ethanolaldehyde carbon yield was about 48%. For (B), the obtained ethanolaldehyde carbon yield was about 53%. Those skilled in the art know how to calculate the ethanolaldehyde carbon yield.

[0340] Example 2

[0341] This example illustrates another aspect of the pyrolytic cracking of sugars in an industrial setting according to the present invention. Figure 8In 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). Figure 8 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). Figure 8 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).

[0342] 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. Only one particle separator (305) is shown, but it should be understood that the particle separator 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.

[0343] 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 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. Figure 8 In FIG. 3 , the approximate boundary separating the dense phase from the lean phase is indicated by curve ( 307 ). Curve ( 307 ) also shows the approximate location of the top surface of the dense fluidized bed of heat-carrying particles.

[0344] In the dense fluidized bed of heat-carrying particles, an indirect heating device (308) is provided to provide the energy required for the pyrolysis cracking step and to compensate for heat loss and product gas loss. 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).

[0345] The heating device (308) may also be arranged outside 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.

[0346] Figure 8 The system can be used for pyrolysis cracking of sugar under industrial conditions. As described in Example 2 of WO 21 / 032590, about 25,000 liters (pile) 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 atomizing gas (303) is fed into the reactor (300) at a rate of 1,380 kg / h. Steam as fluidizing gas (301) is fed into the reactor (300) at a rate of 5,741 kg / h. The following carbon-based yields of mainly C2-C3 oxygenated compounds are obtained from glucose: 57C-% ethanolaldehyde, 10C-% methylglyoxal, 4C-% acetol, 3C-% glyoxal and 10C-% formaldehyde.

[0347] The water content at the outlet O' of the reactor (300) is about 75 vol.% or more based on all gas phase components. The yield of other byproducts (e.g., CO, CO2, acetic acid) may not significantly change the volume fraction of the steam. It should be understood that, for example, changing the flow rate and / or composition of the atomizing gas (303) or the fluidizing gas (301) may change the volume fraction of the steam generated at the outlet O'.

[0348] 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.

[0349] 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 is 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 obvious modifications to the described modes of implementing the present invention that would be apparent to those skilled in the art are intended to be included within the scope of the appended 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 thermal cracking of sugars, wherein the fluidized bed cracking reactor comprises fluidizable heat-carrying particles; c) introducing the feedstock solution into a reactor to pyrolytically crack the sugars to provide a cracked product comprising C1-C3 oxygenates; d) separating solids from the cracked products, 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; wherein the temperature of the cracked products at the reactor outlet is at least 250°C, such as at least 300°C, at least 350°C, at least 400°C or at least 450°C, and The water content is at least 40 vol. %, based on all gas phase components.

2. The process according to claim 1, wherein the water content at the reactor outlet is at least 40 vol.% based on all gas phase components at the reactor outlet.

3. The process according to claim 1 or 2, wherein the steam partial pressure at the reactor outlet is greater than 650 mbar.

4. The process according to any one of claims 1 to 3, wherein the water content at the reactor outlet is at least 60 vol.%, based on all gas phase components at the reactor outlet.

5. The process according to any one of claims 1 to 4, wherein step d) comprises separating solids from the cracked products using a physical separation device.

6. The process according to claim 5, wherein the physical separation device is arranged downstream of the reactor.

7. The method according to claim 5 or 6, wherein the physical separation device is a filter, optionally wherein the filter is selected from bag filters and candle filters.

8. The method according to any one of claims 5 to 7, wherein the filter comprises a filter element having a filtering surface.

9. The method according to any one of claims 5 to 8, wherein the water content is based on all gas phase components at the inlet of the physical separation device.

10. The process according to any one of claims 1 to 9, comprising introducing an atomising gas into the reactor, optionally wherein the water content in the atomising gas is at least 50 wt.%, based on the total weight of the atomising gas.

11. The method according to any one of claims 1 to 10, 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, and / or wherein the sugar is selected from sucrose, lactose, xylose, arabinose, ribose, mannose, tagatose, galactose, glucose and fructose.

12. The method according to any one of claims 1 to 11, wherein the total sugar content in the raw material solution is 30 to 99 wt.%, such as 40 to 90 wt.%, or 50 to 80 wt.%, based on the total weight of the raw material solution.

13. The process according to any one of claims 1 to 12, wherein the cracked product comprises glycolaldehyde.

14. The process according to any one of claims 1 to 13, wherein the cracked product comprises at least 10 wt.% glycolaldehyde, based on the total weight of the cracked product.

15. The process according to any one of claims 1 to 14, wherein the pressure at the reactor outlet is at least 0.9 bara.

16. The process according to any one of claims 1 to 15, comprising 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 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 or each separation step between step c) and step d) comprises separating at least 50 wt.% of solids based on the total weight of solids from the cracked products, optionally wherein the separation step or each separation step between step c) and step d) is carried out in a reactor.

17. A system for pyrolytic cracking of sugars into C1-C3 oxygenates, the system comprising: a) an aqueous raw material solution comprising sugar; b) a fluidized bed cracking reactor configured to pyrolytically crack the sugar and comprising fluidizable heat-carrying particles to provide a cracking product comprising C1-C3 oxygenates; c) a separation device configured to separate solids from the cracked products, 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 feedstock solution, and mixtures thereof; wherein the temperature of the cracked products at the reactor outlet is at least 250°C, such as at least 300°C, at least 350°C, at least 400°C or at least 450°C, and The water content is at least 40 vol. %, based on all gas phase components.

18. The system according to claim 16, characterized in that The features of any one of claims 2 to 16.

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