Process for condensing oxygenate mixture

Abstract

The present application provides a process for at least partially condensing an oxygenate mixture, the process comprising the steps of: (a) providing a vapour phase oxygenate mixture resulting from cleavage of an aqueous carbohydrate solution; (b) at least partially condensing the vapor phase oxygenate mixture to provide a condensate; and (c) combining an antifoaming agent and the condensate.

Description

Technical Field

[0001] The present invention relates to a method and system for at least partially condensing an oxygenate mixture to provide a condensate. Background Art

[0002] Biomass is of particular interest as a raw material because of its potential to supplement and possibly replace petroleum as a feedstock for the preparation of commercial chemicals. In recent years, various technologies for the development of biomass have been investigated.

[0003] Carbohydrates constitute a large part of biomass and various strategies are being developed to effectively use them as feedstocks for the preparation of commercial chemicals. These strategies include various fermentation-based methods, catalyst-based methods, pyrolysis, thermal cracking and other methods such as hydrogenolysis, hydroformylation or acid-catalyzed dehydration.

[0004] The conversion of biomass via pyrolysis processes is desirable because of the high volumetric productivity that can be achieved and because these types of processes are able to convert a wide range of substrates into a small range of products. However, current pyrolysis processes often present challenges when implemented in industrial settings, where, for example, industrial applications require processes with high efficiency and long-term stability.

[0005] One pyrolysis process for converting carbohydrates, in particular sugars, into commercially valuable chemicals is "thermolytic fragmentation". Further process steps may follow. It may also be referred to as "aqueous thermolysis" or "carbohydrate cracking".

[0006] Examples of chemicals produced from biomass include: alternative natural gas, biofuels (such as ethanol and biodiesel), food browning materials, and commercial chemicals such as glycols (ethylene glycol and propylene glycol), acids (lactic acid, acrylic acid, and levulinic acid), and various other important chemical intermediates (epichlorohydrin, isoprene, furfural, and syngas).

[0007] Therefore, new uses for C1-C3 oxygenate products are being developed, and it is expected that the demand for these products will continue to increase. Such oxygenate products can be used, for example, to produce ethylene glycol and propylene glycol by hydrogenating the oxygenate products (see, for example, WO 2016 / 001169), or to remove hydrogen sulfide (see, for example, WO 2017 / 064267). However, many other uses can be envisioned.

[0008] After carbohydrate cleavage, a composition consisting primarily of C1-C3 oxygenates is formed. The primary C1 oxygenate is formaldehyde, which is undesirable in many products because it has high toxicity / carcinogenicity and has been shown to be a catalyst poison (see US2016 / 00213). The primary C2 oxygenate is glycolaldehyde, which is a target product because it can be converted into useful chemicals such as ethylene glycol, glycolic acid, and vinyl methyl glycolate (methyl 2-hydroxy-3-butenoate). The mixture of oxygenates produced by carbohydrate cleavage can be used in many different applications where formaldehyde toxicity may be a problem. Therefore, it is highly desirable to prepare a formaldehyde-free or formaldehyde-depleted composition. US2016 / 002137 discusses a method for removing formaldehyde by reactive distillation; however, this method adds additional process steps.

[0009] WO 02 / 40436 discloses a method for producing glycolaldehyde by aqueous pyrolysis, which comprises: preparing a sugar aqueous solution; atomizing the sugar aqueous solution; injecting the atomized sugar aqueous solution into a reactor heated to 500° C. to 600° C. to produce a gaseous pyrolysis product; cooling the gaseous pyrolysis product in a condenser to obtain a liquid condensate; collecting the liquid condensate in a storage tank to produce a liquid rich in glycolaldehyde; and filtering the liquid rich in glycolaldehyde.

[0010] It is desirable to provide an alternative or improved method and / or system for producing a mixture of oxygenates obtained by cleavage of an aqueous carbohydrate solution. It is also desirable that the production be suitable for industrial scale production. Summary of the invention

[0011] In one aspect, there is provided a method of at least partially condensing an oxygenate mixture, the method comprising the steps of:

[0012] (a) providing a vapor phase oxygenate mixture obtained by cracking an aqueous carbohydrate solution;

[0013] (b) at least partially condensing the vapor-phase oxygenate mixture to provide a condensate; and

[0014] (c) combining an antifoaming agent and the condensate.

[0015] In one aspect, a composition is provided, the composition being prepared by a method comprising the steps of:

[0016] (a) providing a vapor phase oxygenate mixture obtained by cracking an aqueous carbohydrate solution;

[0017] (b) at least partially condensing the vapor-phase oxygenate mixture to provide a condensate; and

[0018] (c) combining the defoamer and the condensate.

[0019] In one aspect, there is provided a condensate prepared by a method comprising the steps of:

[0020] (a) providing a vapor phase oxygenate mixture obtained by cracking an aqueous carbohydrate solution;

[0021] (b) at least partially condensing the vapor-phase oxygenate mixture to provide a condensate; and

[0022] (c) combining the defoamer and the condensate.

[0023] In one aspect, a system configured to at least partially condense an oxygenate mixture is provided, the system comprising:

[0024] (a) a cleavage reactor configured to cleave an aqueous carbohydrate solution to provide a vapor phase oxygenate mixture;

[0025] (b) a condenser configured to at least partially condense the vapor-phase oxygenate mixture to provide a condensate; and

[0026] (c) a unit configured to combine the defoaming agent and the condensate.

[0027] BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Embodiments of the invention are explained by way of example and with reference to the accompanying drawings. The drawings show only examples of embodiments of the invention and therefore they should not be considered limiting of the scope of the invention as the invention is susceptible to other alternative embodiments.

[0029] Figure 1 shows the foam height data for Example 1; and

[0030] Figure 2 It is a schematic diagram of the condensation method of Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0032] method

[0033] As discussed herein, in one aspect, a method of at least partially condensing an oxygenate mixture is provided, the method comprising the steps of:

[0034] (a) providing a vapor phase oxygenate mixture obtained by cracking an aqueous carbohydrate solution;

[0035] (b) at least partially condensing the vapor-phase oxygenate mixture to provide a condensate; and

[0036] (c) combining the defoamer and the condensate.

[0037] We have found that at least partially condensing a vapor phase oxygenate mixture to provide a condensate produces significant amounts of foam as well as the condensate. In commercial scale processes, foam is troublesome to the condenser and / or units downstream of the condenser because these units are typically not configured to handle foam.

[0038] We have also found that by combining a defoamer with a condensate to reduce or suppress foaming, it is possible to provide a process for producing a mixture of oxygenates obtained from the cleavage of an aqueous carbohydrate solution which is suitable for industrial scale production.

[0039] In one aspect, the process is a continuous process, which is generally preferred in industrial scale processes.

[0040] Step (a) - Providing a vapor phase oxygenate mixture obtained from the cracking of an aqueous carbohydrate solution

[0041] As discussed herein, the process of the present invention requires step (a) providing a vapor phase oxygenate mixture obtained from the cracking of an aqueous carbohydrate solution.

[0042] The cleavage of the aqueous carbohydrate solution can be achieved by any suitable means. In one aspect, the cleavage of the aqueous carbohydrate solution is thermal cleavage. In one aspect, the cleavage of the aqueous carbohydrate solution is thermal cleavage. The cleavage of the aqueous carbohydrate solution can be carried out by any suitable method. In one aspect, the cleavage of the aqueous carbohydrate solution is carried out as described in WO2020 / 016209 or as described in WO2017 / 216311.

[0043] In this context, thermal cracking means that carbohydrates are selectively decomposed into oxygenate mixtures by heating sugar to an intermediate temperature (400-600 degrees Celsius) under inert conditions with a very short residence time. The heating rate adopted is very high (>1000 degrees Celsius / second), and the residence time is short (<1 second) to minimize the selectivity to polymeric products or permanent gases. An important compound formed by thermal cracking of sugar is glycolaldehyde (hydroxyacetaldehyde). Glycolaldehyde is the smallest known compound containing hydroxyl and carbonyl groups at the same time, and it can be referred to as a sugar compound. It is highly reactive and is a useful platform chemical for the manufacture of other chemicals such as ethylene glycol and glycolic acid. It is known that it is an unstable molecule at elevated temperatures. See, for example, EP 0158517 B1, which suggests low-temperature vacuum distillation to purify glycolaldehyde.

[0044] After the thermal cracking of carbohydrates, a composition (i.e., a vapor phase oxygenate mixture) consisting mainly of C1-C3 oxygenates is formed. In addition to the main product, i.e., C2 oxygenate glycolaldehyde, the product obtained by carbohydrate cracking (e.g., thermal decomposition) also contains different amounts of C1 to C3 oxygenates, such as formaldehyde, glyoxal, pyruvic acid and acetol, and a small amount of macromolecules. The presence of C1 oxygenates (formaldehyde) is usually undesirable, and for some applications, it is necessary to remove formaldehyde. It is also undesirable to have larger (and heavier) molecules in the condensate of the pyrolysis product. Typically, a large amount of resources may be spent on condensed oxygenate mixtures (e.g., pyrolysis products based on glucose) by distillation fractionation. This separation may produce oxygenate syrups rich in glycolaldehyde and free of high-boiling byproducts.

[0045] In one aspect, a thermal cracking step is incorporated into the process. In one aspect, the invention comprises the step of thermal cracking an aqueous carbohydrate solution to provide a vapor phase oxygenate mixture of step (a). In one aspect, the oxygenate mixture obtained directly from the thermal cracking of an aqueous carbohydrate solution is subjected to step (b).

[0046] In one aspect, thermal cracking of an aqueous carbohydrate solution to provide a vapor phase oxygenate mixture includes adding the aqueous carbohydrate solution to a thermal cracking reactor.

[0047] In one aspect, the aqueous solution of carbohydrate is added to the thermal cracking reactor at a rate of at least 0.001 kg / h, or at least 0.01 kg / h, or at least 0.1 kg / h, or at least 1 kg / h, or at least 2 kg / h, or at least 5 kg / h, or at least 8 kg / h, or at least 10 kg / h, or at least 12 kg / h, or at least 15 kg / h.

[0048] In one aspect, the aqueous solution of carbohydrates is added to the thermal cracking reactor at a rate of no more than 150 kg / h, or no more than 140 kg / h, or no more than 130 kg / h, or no more than 120 kg / h, or no more than 110 kg / h, or no more than 100 kg / h, or no more than 90 kg / h, or no more than 80 kg / h, or no more than 70 kg / h, or no more than 60 kg / h.

[0049] In one aspect, the aqueous solution of carbohydrate is added to the thermal cracking reactor at a rate of 0.001 kg / h to 150 kg / h, or 0.01 kg / h to 140 kg / h, or 0.1 kg / h to 130 kg / h, or 1 kg / h to 120 kg / h, or 2 kg / h to 110 kg / h, or 5 kg / h to 100 kg / h, or 8 kg / h to 90 kg / h, or 10 kg / h to 80 kg / h, or 12 kg / h to 70 kg / h, or 15 kg / h to 60 kg / h.

[0050] In one aspect, the thermal cracking of the aqueous carbohydrate solution to provide a vapor phase oxygenate mixture includes adding a flushing gas to the thermal cracking reactor. The flushing gas may include or consist of a fluidizing gas. Those skilled in the art are familiar with the function of a fluidizing gas and understand that a fluidizing gas can be used to fluidize heat-carrying particles (e.g., sand) in the cracking reactor.

[0051] In one aspect, the flushing gas is inert. In one aspect, the flushing gas may include air or nitrogen or steam. Suitable flushing gases are known to those skilled in the art.

[0052] The carbohydrate in the carbohydrate aqueous solution can be any suitable carbohydrate. In one aspect, the carbohydrate in the carbohydrate aqueous solution is selected from monosaccharides, disaccharides and mixtures thereof. In one aspect, the carbohydrate in the carbohydrate aqueous solution is at least a monosaccharide. In one aspect, the carbohydrate in the carbohydrate aqueous solution is selected from sucrose, xylose, arabinose, mannose, tagatose, galactose, glucose, fructose, inulin, amylopectin (starch). In one aspect, the carbohydrate in the carbohydrate aqueous solution is at least glucose. In one aspect, the aqueous solution of carbohydrate is syrup.

[0053] In one aspect, the carbohydrates in the aqueous carbohydrate solution comprise at least 20 wt.% monosaccharides based on the total amount of carbohydrates. In one aspect, the carbohydrates in the aqueous carbohydrate solution comprise at least 30 wt.% monosaccharides based on the total amount of carbohydrates. In one aspect, the carbohydrates in the aqueous carbohydrate solution comprise at least 40 wt.% monosaccharides based on the total amount of carbohydrates. In one aspect, the carbohydrates in the aqueous carbohydrate solution comprise at least 50 wt.% monosaccharides based on the total amount of carbohydrates. In one aspect, the carbohydrates in the aqueous carbohydrate solution comprise at least 60 wt.% monosaccharides based on the total amount of carbohydrates. In one aspect, the carbohydrates in the aqueous carbohydrate solution comprise at least 70 wt.% monosaccharides based on the total amount of carbohydrates. In one aspect, the carbohydrates in the aqueous carbohydrate solution comprise at least 80 wt.% monosaccharides based on the total amount of carbohydrates. In one aspect, the carbohydrates in the aqueous carbohydrate solution comprise at least 90 wt.% monosaccharides based on the total amount of carbohydrates. In one aspect, the carbohydrates in the aqueous carbohydrate solution comprise at least 95 wt.% monosaccharides based on the total amount of carbohydrates.

[0054] In one aspect, the carbohydrates in the aqueous carbohydrate solution comprise at least 20 wt.% glucose based on the total amount of carbohydrates. In one aspect, the carbohydrates in the aqueous carbohydrate solution comprise at least 30 wt.% glucose based on the total amount of carbohydrates. In one aspect, the carbohydrates in the aqueous carbohydrate solution comprise at least 40 wt.% glucose based on the total amount of carbohydrates. In one aspect, the carbohydrates in the aqueous carbohydrate solution comprise at least 50 wt.% glucose based on the total amount of carbohydrates. In one aspect, the carbohydrates in the aqueous carbohydrate solution comprise at least 60 wt.% glucose based on the total amount of carbohydrates. In one aspect, the carbohydrates in the aqueous carbohydrate solution comprise at least 70 wt.% glucose based on the total amount of carbohydrates. In one aspect, the carbohydrates in the aqueous carbohydrate solution comprise at least 80 wt.% glucose based on the total amount of carbohydrates. In one aspect, the carbohydrates in the aqueous carbohydrate solution comprise at least 90 wt.% glucose based on the total amount of carbohydrates. In one aspect, the carbohydrates in the aqueous carbohydrate solution comprise at least 95 wt.% glucose based on the total amount of carbohydrates.

[0055] The aqueous solution of carbohydrates may contain any suitable amount of carbohydrates. In one aspect, the aqueous solution of carbohydrates contains carbohydrates in an amount of at least 10 wt.% based on the aqueous solution. In one aspect, the aqueous solution of carbohydrates contains carbohydrates in an amount of at least 20 wt.% based on the aqueous solution. In one aspect, the aqueous solution of carbohydrates contains carbohydrates in an amount of at least 30 wt.% based on the aqueous solution. In one aspect, the aqueous solution of carbohydrates contains carbohydrates in an amount of at least 40 wt.% based on the aqueous solution. In one aspect, the aqueous solution of carbohydrates contains carbohydrates in an amount of at least 50 wt.% based on the aqueous solution. In one aspect, the aqueous solution of carbohydrates contains carbohydrates in an amount of at least 60 wt.% based on the aqueous solution. In one aspect, the aqueous solution of carbohydrates contains glucose in an amount of at least 10 wt.% based on the aqueous solution. In one aspect, the aqueous solution of carbohydrates contains glucose in an amount of at least 20 wt.% based on the aqueous solution. In one aspect, the aqueous solution of carbohydrates contains glucose in an amount of at least 30 wt.% based on the aqueous solution. In one aspect, the aqueous solution of carbohydrates contains glucose in an amount of at least 40 wt.% based on the aqueous solution. In one aspect, the aqueous solution of carbohydrates contains glucose in an amount of at least 50 wt.% based on the aqueous solution. In one aspect, the aqueous carbohydrate solution comprises glucose in an amount of at least 60 wt. %, based on the aqueous solution.

[0056] For aqueous solutions of carbohydrates, the upper limit of carbohydrates is limited by the solubility of each carbohydrate. For carbohydrates, disaccharides and monosaccharides, and any sugar (especially glucose), based on aqueous solutions, it is conceivable that the upper limit of carbohydrates is 95wt.%, such as 96wt.%, 97wt.%, 98wt.%, 99wt.%.

[0057] We find that at least partial condensation of a vapor phase oxygenate mixture derived from biomass is particularly prone to producing a large amount of foam. In one aspect, the vapor phase oxygenate mixture is derived from biomass. In one aspect, the aqueous solution of carbohydrates is derived from biomass. In one aspect, the carbohydrates in the aqueous carbohydrate solution are derived from biomass. In one aspect, the biomass is selected from plant biomass, animal biomass, or a combination thereof. Non-limiting examples of biomass include wood, wood residues, forestry waste, agricultural waste (e.g., straw, stalks, corn, wheat, bagasse, and green agricultural waste), industrial and agricultural waste (e.g., bagasse, beets, and rice husks), animal manure (e.g., cow dung and poultry manure), industrial waste (e.g., papermaking black liquor), sewage, municipal solid waste, and food processing waste.

[0058] Those skilled in the art will appreciate that the components of the vapor phase oxygenate mixture (eg, glycolaldehyde to formaldehyde) have a mass ratio that can vary depending on the nature of the aqueous carbohydrate solution (carbohydrate feed) and the cracking conditions.

[0059] In one aspect, the vapor phase oxygenate mixture includes C1-C3 oxygenates. In one aspect, the vapor phase oxygenate mixture comprises at least 40 wt.% of C1-C3 oxygenates, based on the total weight of the vapor phase oxygenate mixture. In one aspect, the vapor phase oxygenate mixture comprises at least 50 wt.% of C1-C3 oxygenates, based on the total weight of the vapor phase oxygenate mixture. In one aspect, the vapor phase oxygenate mixture comprises at least 60 wt.% of C1-C3 oxygenates, based on the total weight of the vapor phase oxygenate mixture. In one aspect, the vapor phase oxygenate mixture comprises at least 70 wt.% of C1-C3 oxygenates, based on the total weight of the vapor phase oxygenate mixture.

[0060] There is no upper limit beyond which the invention does not work. However, for any of the lower values ​​given above, an upper limit of 90 wt.% of C1-C3 oxygenate, based on the total weight of the vapor phase oxygenate mixture, can be envisioned.

[0061] In one aspect, the vapor phase oxygenate mixture consists primarily of C1-C3 oxygenates. In one aspect, the vapor phase oxygenate mixture consists essentially of C1-C3 oxygenates.

[0062] Step (b) - subjecting the vapor phase oxygenate mixture to at least partial condensation to provide a condensate

[0063] As discussed herein, the present process requires step (b) of at least partially condensing the vapor phase oxygenate mixture to provide a condensate.

[0064] The present method encompasses partial condensation of a vapor-phase oxygenate mixture. By "partial condensation," it is meant that a portion of the vapor-phase oxygenate mixture is condensed in the condensing step to provide a condensate. Where the condensation is a partial condensation, the condensate produced thereby may be referred to as a "partially condensed condensate." The present method encompasses complete condensation of a vapor-phase oxygenate mixture to provide a condensate. By "complete condensation," it is meant that substantially all of the vapor-phase oxygenate mixture is condensed in the condensing step to provide a condensate. Where the condensation is a complete condensation, the condensate produced thereby may be referred to as a "completely condensed condensate." Those skilled in the art will appreciate that partial condensation and complete condensation may produce condensates having different compositions.

[0065] In one aspect, there is provided a method for completely condensing an oxygenate mixture, the method comprising the steps of:

[0066] (a) providing a vapor phase oxygenate mixture obtained by cracking an aqueous carbohydrate solution;

[0067] (b) completely condensing the vapor phase oxygenate mixture to provide a complete condensate; and

[0068] (c) combining the defoamer and the condensate.

[0069] Those skilled in the art will appreciate that the vapor phase oxygenate mixture may have a ratio of glycolaldehyde to formaldehyde that may vary depending on the nature of the aqueous carbohydrate solution (carbohydrate feed) and the cracking conditions.

[0070] In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the vapor phase oxygenate mixture is from 2:1 to 18:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the vapor phase oxygenate mixture is from 3:1 to 18:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the vapor phase oxygenate mixture is from 4:1 to 18:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the vapor phase oxygenate mixture is from 5:1 to 18:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the vapor phase oxygenate mixture is from 2:1 to 15:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the vapor phase oxygenate mixture is from 3:1 to 15:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the vapor phase oxygenate mixture is from 4:1 to 15:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the vapor phase oxygenate mixture is from 5:1 to 15:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the vapor phase oxygenate mixture is from 2: 1 to 10: 1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the vapor phase oxygenate mixture is from 3: 1 to 10: 1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the vapor phase oxygenate mixture is from 4: 1 to 10: 1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the vapor phase oxygenate mixture is from 5: 1 to 10: 1.

[0071] As will be appreciated by those skilled in the art, the composition of the condensate may vary depending on whether partial or complete condensation or complete condensation is performed. For example, if partial condensation is performed in step (b), the mass ratios of the components of the vapor phase oxygenate mixture (e.g., glycolaldehyde to formaldehyde) may be different from the mass ratios of the components of the condensate. In contrast, if complete condensation is performed in step (b), the mass ratios of the components of the vapor phase oxygenate mixture (e.g., glycolaldehyde to formaldehyde) may be substantially the same as the mass ratios of the components of the condensate.

[0072] In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is at least 5:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is at least 10:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is at least 15:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is at least 20:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is at least 30:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is at least 40:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is at least 50:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is at least 60:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is at least 70:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is at least 80:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is at least 90:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is at least 100:1.

[0073] In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is not greater than 500:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is not greater than 400:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is not greater than 300:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is not greater than 200:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is not greater than 180:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is not greater than 160:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is not greater than 150:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is not greater than 140:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is not greater than 130:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is not greater than 120:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is not greater than 110:1. In one aspect, the condensate has a mass ratio of glycolaldehyde to formaldehyde of no greater than 100:1.

[0074] In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is from 10:1 to 200:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is from 10:1 to 180:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is from 10:1 to 160:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is from 10:1 to 150:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is from 10:1 to 140:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is from 10:1 to 130:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is from 10:1 to 120:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is from 10:1 to 110:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is from 10:1 to 100:1.

[0075] In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is from 30:1 to 200:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is from 30:1 to 180:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is from 30:1 to 160:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is from 30:1 to 150:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is from 30:1 to 140:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is from 30:1 to 130:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is from 30:1 to 120:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is from 30:1 to 130:1. In one aspect, the mass ratio of ethanolaldehyde to formaldehyde of the condensate is from 30:1 to 100:1.

[0076] Those skilled in the art can easily determine the method parameters required for at least partial condensation of the present invention. The key parameters are the composition of the vapor phase oxygenate mixture, the temperature of at least partial condensation and the pressure of at least partial condensation. Usually, the composition of the vapor phase oxygenate mixture will be limited by the cracking process. Similarly, the pressure of at least partial condensation can usually be limited by the requirements of the upstream process. Therefore, the temperature used for at least partial condensation is a parameter that is usually controlled to achieve the required separation. If pressure is not limited by upstream process considerations and can be freely controlled, then in principle it can be used as a control parameter (at a fixed temperature). However, for most practical applications, it will be more appropriate to control the temperature of at least partial condensation. In any case, the considerations for using pressure as a control parameter will be the same as those outlined below for temperature.

[0077] In one aspect, the condensate is condensed at a temperature of 0°C to 150°C. In one aspect, the condensate is condensed at a temperature of 10°C to 150°C. In one aspect, the condensate is condensed at a temperature of 20°C to 150°C. In one aspect, the condensate is condensed at a temperature of 30°C to 150°C. In one aspect, the condensate is condensed at a temperature of 30°C to 130°C. In one aspect, the condensate is condensed at a temperature of 0°C to 90°C. In one aspect, the condensate is condensed at a temperature of 5°C to 90°C. In one aspect, the condensate is condensed at a temperature of 30°C to 90°C. In one aspect, the condensate is condensed at a temperature of 40°C to 90°C. In one aspect, the condensate is condensed at a temperature of 30°C to 70°C. In one aspect, the condensate is condensed at a temperature of 40°C to 60°C.

[0078] In one aspect, there is provided a method of at least partially condensing an oxygenate mixture, the method comprising the steps of:

[0079] (a) providing a vapor phase oxygenate mixture obtained from cracking of an aqueous carbohydrate solution; and

[0080] (b) subjecting the vapor-phase oxygenate mixture to at least partial condensation to provide a condensate, wherein the condensate is condensed at a temperature of 0° C. to 150° C.; and

[0081] (c) combining the defoamer and the condensate.

[0082] In one aspect, the temperature of the condensate leaving the condenser is from 0°C to 150°C. In one aspect, the temperature of the condensate leaving the condenser is from 10°C to 150°C. In one aspect, the temperature of the condensate leaving the condenser is from 20°C to 150°C. In one aspect, the temperature of the condensate leaving the condenser is from 30°C to 150°C. In one aspect, the temperature of the condensate leaving the condenser is from 0°C to 90°C. In one aspect, the temperature of the condensate leaving the condenser is from 5°C to 90°C. In one aspect, the temperature of the condensate leaving the condenser is from 40°C to 90°C. In one aspect, the temperature of the condensate leaving the condenser is from 30°C to 70°C. In one aspect, the temperature of the condensate leaving the condenser is from 40°C to 60°C.

[0083] In one aspect, there is provided a method of at least partially condensing an oxygenate mixture, the method comprising the steps of:

[0084] (a) providing a vapor phase oxygenate mixture obtained from cracking of an aqueous carbohydrate solution; and

[0085] (b) subjecting the vapor-phase oxygenate mixture to at least partial condensation to provide a condensate, wherein the condensate formed by the at least partial condensation has a temperature of 0°C to 150°C; and

[0086] (c) combining the defoamer and the condensate.

[0087] As discussed herein, prior to step (b), the oxygenate mixture may be subjected to an intermediate step. For example, an initial partial condensation may be performed on the oxygenate mixture prior to the partial condensation step (b). In one aspect, the oxygenate mixture obtained directly from the cleavage of the carbohydrate aqueous solution is subjected to step (b). For example, the intermediate step may be selected based on the composition of the oxygenate mixture obtained directly from the cleavage of the carbohydrate aqueous solution. As will be appreciated by those skilled in the art, in addition, the composition of the oxygenate mixture obtained directly from the cleavage of the carbohydrate aqueous solution will also depend on the composition of the carbohydrate aqueous solution and the cleavage process parameters.

[0088] In one aspect, subjecting the vapor phase oxygenate mixture to at least partial condensation comprises feeding an input stream comprising the vapor phase oxygenate mixture through (or into) a condenser to provide a condensate and an output stream. Where partial condensation is used, the output stream may comprise a partially condensed vapor phase. In one aspect, the input stream comprises a purge gas. The condensate and the output stream exit the condenser, for example, at or towards the top of the condenser.

[0089] Downstream of the condenser, a catalyst may be used to remove one or more environmentally harmful components from the gas phase (e.g. from the output stream). We have found that foam can damage or destroy the catalyst. By using a defoamer, the catalyst can be protected from the effects of foaming, thereby maintaining its performance.

[0090] In one aspect, the temperature of the output stream leaving the condenser is from 0°C to 50°C. In one aspect, the temperature of the output stream leaving the condenser is from 0°C to 40°C. In one aspect, the temperature of the output stream leaving the condenser is from 0°C to 30°C. In one aspect, the temperature of the output stream leaving the condenser is from 0°C to 20°C. In one aspect, the temperature of the output stream leaving the condenser is from 10°C to 20°C.

[0091] In one aspect, at least partially condensing the vapor-phase oxygenate mixture comprises passing an input stream comprising the vapor-phase oxygenate mixture and a purge gas to a condenser to provide a condensate and an output stream comprising the purge gas.

[0092] In one aspect, subjecting the vapor phase oxygenate mixture to at least partial condensation comprises recycling at least a portion of the output stream comprising the purge gas into the input stream. We have found that recycling the output stream in an industrial scale process can result in the formation of significant amounts of foam. However, the present invention allows such recycling in an industrial scale process with the aid of a defoamer while producing reduced levels of foam (e.g., acceptable or minimal amounts of foam).

[0093] In one aspect, at least partially condensing the vapor-phase oxygenate mixture includes splitting the condensate into at least a condensate product stream and a condensate recycle stream.

[0094] In one aspect, the mass ratio of the condensate recycle stream to the condensate product stream is from 5: 1 to 50: 1. In one aspect, the mass ratio of the condensate recycle stream to the condensate product stream is from 10: 1 to 30: 1. In one aspect, the mass ratio of the condensate recycle stream to the condensate product stream is from 10: 1 to 20: 1.

[0095] In one aspect, at least partially condensing the vapor-phase oxygenate mixture includes adding a condensate recycle stream to a condenser.

[0096] In one aspect, the condensate is cooled. In one aspect, the condensate recycle stream is cooled prior to adding the condensate recycle stream to the condenser. We have found that adding the condensate (e.g., the condensate recycle stream) to the condenser promotes condensation of the vapor phase oxygenate mixture.

[0097] In one aspect, the temperature of the condensate recycle stream added to the condenser is from 0°C to 50°C. In one aspect, the temperature of the condensate recycle stream added to the condenser is from 0°C to 40°C. In one aspect, the temperature of the condensate recycle stream added to the condenser is from 0°C to 30°C. In one aspect, the temperature of the condensate recycle stream added to the condenser is from 0°C to 20°C. In one aspect, the temperature of the condensate recycle stream added to the condenser is from 10°C to 20°C. In the context, the temperature of the condensate recycle stream added to the condenser may refer to the temperature of the condensate recycle stream entering the condenser.

[0098] In one aspect, the condensate recycle stream is added to the condenser at or towards the top of the condenser. In this way, the condensate flows through the condenser under gravity. In one aspect, the condensate recycle stream is added to the condenser at or towards the bottom of the condenser.

[0099] In one aspect, the condenser includes a packing material. The packing material increases the contact area between the condensate to be recycled, the defoamer (if applicable), and the vapor phase oxygenate mixture (e.g., the input stream) in the condenser. Those skilled in the art will know suitable packing materials.

[0100] In one aspect, the vapor-phase oxygenate mixture (or input stream) is filtered prior to at least partially condensing the vapor-phase oxygenate mixture.

[0101] Step (c) - Combining the defoamer and condensate

[0102] As discussed herein, the present method requires step (c) of combining the antifoaming agent and the condensate.

[0103] In the context of the present invention, it is understood that defoamers can eliminate existing foam, or prevent foam formation, or both eliminate existing bubbles and prevent foam formation. Therefore, in the context of the present invention, it is understood that defoamers can achieve one or both of eliminating existing foam and preventing foam formation.

[0104] In one aspect, combining the defoamer and the condensate comprises adding the defoamer to the condensate. In one aspect, combining the defoamer and the condensate comprises adding the defoamer to the condensate continuously or intermittently.

[0105] In one aspect, combining the defoamer and the condensate comprises adding the condensate to the defoamer.For example, the defoamer can be contained in a container to which the condensate is added.

[0106] In one aspect, combining the defoamer and the condensate comprises combining the defoamer and the condensate in a condenser. In one aspect, combining the defoamer and the condensate comprises adding the defoamer to the condenser.

[0107] In one aspect, combining the antifoam agent and the condensate includes adding a condensate recycle stream to the condenser.

[0108] In one aspect, combining the antifoam agent and the condensate includes adding the antifoam agent to the condensate recycle stream to form a mixture, and adding the mixture to the condenser.

[0109] In one aspect, the mixture is split into multiple streams. In one aspect, each of the multiple streams is added to a corresponding portion of the condenser. In one aspect, at least a portion of the mixture is added to the condenser at or toward the top of the condenser (e.g., by means of a stream). In one aspect, at least a portion of the mixture is added to the condenser (e.g., by means of a stream) above the packing material. In one aspect, at least a portion of the mixture is added to the condenser (e.g., by means of a stream) at or toward the bottom of the condenser. In one aspect, at least a portion of the mixture is added to the condenser (e.g., by means of a stream) below the packing material. "Top," "bottom," "above," and "below" are meant relative to gravity.

[0110] In one aspect, at least a portion of the mixture is fed to the condenser in countercurrent flow to the flow of vapor-phase oxygenate mixture in the condenser.

[0111] In one aspect, the temperature of the mixture added to the condenser is 0°C to 50°C. In one aspect, the temperature of the mixture added to the condenser is 0°C to 40°C. In one aspect, the temperature of the mixture added to the condenser is 0°C to 30°C. In one aspect, the temperature of the mixture added to the condenser is 0°C to 20°C. In one aspect, the temperature of the mixture added to the condenser is 10°C to 20°C. In the context, the temperature of the mixture added to the condenser may refer to the temperature of the mixture entering the condenser.

[0112] Defoaming agent

[0113] In one aspect, the antifoaming agent is added to the condensate at a rate of at least 0.0000001 mL / h, or at least 0.000001 mL / h, or at least 0.00001 mL / h, or at least 0.0001 mL / h, or at least 0.001 mL / h, or at least 0.01 mL / h, or at least 0.1 mL / h, or at least 1 mL / h, or at least 1.2 mL / h, or at least 1.5 mL / h.

[0114] In one aspect, the defoaming agent is added to the condensate at a rate of no greater than 200 mL / h, or no greater than 100 mL / h, or no greater than 50 mL / h, or no greater than 20 mL / h, or no greater than 10 mL / h, or no greater than 8 mL / h, or no greater than 6 mL / h, or no greater than 5 mL / h, or no greater than 4 mL / h, or no greater than 3.8 mL / h.

[0115] In one aspect, the defoaming agent is added to the condensate at a rate of 0.0000001 mL / h to 200 mL / h, or 0.000001 mL / h to 100 mL / h, or 0.00001 mL / h to 50 mL / h, or 0.0001 mL / h to 20 mL / h, or 0.001 mL / h to 10 mL / h, or 0.01 mL / h to 8 mL / h, or 0.1 mL / h to 6 mL / h, or 1 mL / h to 5 mL / h, or 1.2 mL / h to 4 mL / h, or 1.5 mL / h to 3.8 mL / h.

[0116] In one aspect, the mass ratio of defoamer and condensate in the combined defoamer to condensate is at least 1:1000000, or at least 1:800000, or at least 1:500000, or at least 1:200000, or at least 1:100000, or at least 1:80000, or at least 1:50000, or at least 1:25000, or at least 1:20000, or at least 1:18000.

[0117] In one aspect, the mass ratio of the defoamer and condensate combined is no greater than 1:1, or no greater than 1:2, or no greater than 1:4, or no greater than 1:6, or no greater than 1:8, or no greater than 1:10, or no greater than 1:12, or no greater than 1:14, or no greater than 1:16, or no greater than 1:18.

[0118] In one aspect, the mass ratio of the defoamer and condensate combined is from 1:1000000 to 1:1, or from 1:800000 to 1:2, or from 1:500000 to 1:4, or from 1:200000 to 1:6, or from 1:100000 to 1:8, or from 1:80000 to 1:10, or from 1:50000 to 1:12, or from 1:25000 to 1:14, or from 1:20000 to 1:16, or from 1:18000 to 1:18.

[0119] In one aspect, the surface tension of the defoaming agent at 20°C is no greater than 70 mN / m, or no greater than 60 mN / m, or no greater than 50 mN / m, or no greater than 40 mN / m, or no greater than 35 mN / m, or no greater than 30 mN / m, or no greater than 25 mN / m, or no greater than 20 mN / m, or no greater than 15 mN / m, or no greater than 10 mN / m, or no greater than 5 mN / m.

[0120] In one aspect, the antifoaming agent has a surface tension of 20 to 30 mN / m at 20°C.

[0121] Surface tension can be measured using any suitable method, such as using a surface tensiometer. In one aspect, surface tension is measured using a Wilhelmy plate tensiometer, a Du Nouy ring tensiometer, or a bubble pressure tensiometer.

[0122] In one aspect, the defoamer comprises one or more active ingredients. One skilled in the art will understand that the "active ingredient" of a defoamer is the portion of the defoamer that is responsible for its defoaming effect.

[0123] In one aspect, an "antifoaming agent" comprises essentially, consists essentially of, or consists of one or more active ingredients.

[0124] In one aspect, the defoaming agent has a total active ingredient content of at least 0.0000001 wt.%, or at least 0.000001 wt.%, or at least 0.00001 wt.%, or at least 0.0001 wt.%, or at least 0.001 wt.%, or at least 0.01 wt.%, or at least 0.1 wt.%, or at least 0.2 wt.%, or at least 0.3 wt.%, or at least 0.4 wt.%, based on the total weight of the defoaming agent.

[0125] In one aspect, the defoaming agent has a total active ingredient content of up to 100 wt.%. In one aspect, the defoaming agent has a total active ingredient content of no more than 95 wt.%, or no more than 90 wt.%, or no more than 80 wt.%, or no more than 70 wt.%, or no more than 60 wt.%, or no more than 50 wt.%, or no more than 40 wt.%, or no more than 30 wt.%, or no more than 25 wt.%, or no more than 20 wt.%, based on the total weight of the defoaming agent.

[0126] In one aspect, the defoaming agent has a total active ingredient content of 0.0000001 wt.% to 100 wt.%, or 0.0000001 wt.% to 95 wt.%, or 0.000001 wt.% to 90 wt.%, or 0.00001 wt.% to 80 wt.%, or 0.0001 wt.% to 70 wt.%, or 0.001 wt.% to 60 wt.%, or 0.01 wt.% to 50 wt.%, or 0.1 wt.% to 40 wt.%, or 0.2 wt.% to 30 wt.%, or 0.3 wt.% to 25 wt.%, or 0.4 wt.% to 20 wt.%.

[0127] In one aspect, each of the one or more active ingredients is independently selected from alcohols, ethers, carboxylic acids, esters, polysiloxanes (e.g., silicones), silica, oils (e.g., vegetable oils or mineral oils), waxes, and acrylates. In one aspect, each of the one or more active ingredients is independently selected from alcohols and polysiloxanes.

[0128] In one aspect, where each of the one or more active ingredients is selected from alcohols, the antifoaming agent may substantially comprise, consist essentially of, or consist of the one or more active ingredients.

[0129] In one aspect, where each of the one or more active ingredients is selected from polysiloxanes, the defoaming agent may have at least 0.0000001 wt.%, or at least 0.000001 wt.%, or at least 0.00001 wt.%, or at least 0.0001 wt.%, or at least 0.001 wt.%, or at least 0.001 wt.%, or at least 0.01 wt.%, or at least 0.1 wt.%, or at least 1 wt.%, or at least 5 wt.% of polysiloxanes, based on the total weight of the defoaming agent.

[0130] In one aspect, where each of the one or more active ingredients is selected from polysiloxanes, the defoaming agent may have no more than 100 wt.%, or no more than 95 wt.%, or no more than 90 wt.%, or no more than 80 wt.%, or no more than 70 wt.%, or no more than 60 wt.%, or no more than 50 wt.%, or no more than 40 wt.%, or no more than 30 wt.%, or no more than 20 wt.% of polysiloxanes based on the total weight of the defoaming agent.

[0131] In one aspect, where each of the one or more active ingredients is selected from polysiloxanes, the defoaming agent may have 0.0000001 wt.% to 100 wt.%, or 0.0000001 wt.% to 95 wt.%, or 0.000001 wt.% to 90 wt.%, or 0.00001 wt.% to 80 wt.%, or 0.0001 wt.% to 70 wt.%, or 0.001 wt.% to 60 wt.%, or 0.01 wt.% to 50 wt.%, or 0.1 wt.% to 40 wt.%, or 1 wt.% to 30 wt.%, or 5 wt.% to 20 wt.% of polysiloxanes, based on the total weight of the defoaming agent.

[0132] In one aspect, the antifoam comprises an aqueous solution. In one aspect, the antifoam comprises an aqueous solution of one or more active ingredients.

[0133] In one aspect, the defoamer comprises an emulsion. In one aspect, the defoamer comprises an emulsion containing a polysiloxane.

[0134] In one aspect, the alcohol is selected from primary alcohols. In one aspect, the alcohol is selected from secondary alcohols. In one aspect, the alcohol is selected from tertiary alcohols.

[0135] In one aspect, the alcohol is selected from C1-C12 alcohols. In one aspect, the alcohol is selected from C1-C10 alcohols. In one aspect, the alcohol is selected from C1-C8 alcohols. In one aspect, the alcohol is selected from C1-C6 alcohols. In one aspect, the alcohol is selected from C1-C4 alcohols. In one aspect, the alcohol is selected from propanol. In one aspect, the alcohol is selected from 1-propanol and 2-propanol. In one aspect, the alcohol is 2-propanol.

[0136] In one aspect, the alcohol is selected from polyalkylene glycols. In one aspect, the alcohol is polyethylene glycol.

[0137] In one aspect, the polysiloxane is selected from polydimethylsiloxane.

[0138] Other process steps

[0139] The method of the present invention may include one or more other steps. These one or more other steps may be before, after or in between the steps listed herein.

[0140] In one aspect, the method comprises the further step of recovering the condensate (e.g., recovering at least a portion of the condensate product stream thereof). In one aspect, the condensate is recovered by distillation. In one aspect, the condensate is recovered by solvent extraction.

[0141] Composition

[0142] In one aspect, a composition prepared by the method described herein is provided. The composition comprises condensate and a defoaming agent.

[0143] Condensate

[0144] In one aspect, a condensate prepared by the method described herein is provided.

[0145] system

[0146] As described herein, in one aspect, there is provided a system configured to at least partially condense an oxygenate mixture, the system comprising:

[0147] (a) a cleavage reactor configured to cleave an aqueous carbohydrate solution to provide a vapor phase oxygenate mixture;

[0148] (b) a condenser configured to at least partially condense the vapor-phase oxygenate mixture to provide a condensate; and

[0149] (c) a unit configured to combine the defoaming agent and the condensate.

[0150] In one aspect, a system is configured to at least partially condense an oxygenate mixture by performing the methods described herein.

[0151] Those skilled in the art know suitable types of cracking reactors. In one aspect, the cracking reactor is a thermal cracking reactor. In one aspect, the cracking reactor is a pyrolysis cracking reactor. In one aspect, the cracking reactor is a fluidized bed reactor. In one aspect, the fluidized bed reactor is selected from a bubbling bed reactor, a turbulent bed reactor, and a riser reactor.

[0152] In one aspect, the cleavage reactor comprises one or more of a feed inlet; a product outlet; a riser; and a fluidizing gas inlet.

[0153] Those skilled in the art will know suitable condensers. In one aspect, the condenser is selected from a water-cooled condenser, an air-cooled condenser, and an evaporative condenser. In one aspect, the condenser is a cooling tower.

[0154] In one aspect, the system includes a separator configured to separate particulate matter from the vapor phase oxygenate mixture. The separator can be a filter. The particulate matter can be, for example, dust from a cracking reactor. In aspects using heat-carrying particles, the particulate matter can include heat-carrying particles from a cracking reactor or fragments thereof.

[0155] As discussed herein, the present invention encompasses partial condensation of a vapor phase oxygenate mixture to provide a condensate, and / or complete condensation of a vapor phase oxygenate mixture to provide a condensate. In one aspect, the system can include a single condenser. Where the system includes a single condenser, the condenser can be used for complete condensation of the vapor phase oxygenate mixture in step (b). In one aspect, the system can include multiple condensers. Where the system includes multiple condensers, the condenser can be used for multiple partial condensations of the vapor phase oxygenate mixture in step (b).

[0156] Any suitable unit configured to combine the antifoam agent and the condensate may be used.

[0157] In one aspect, the unit includes a disperser configured to disperse the defoamer. In one aspect, the disperser is configured to disperse the defoamer continuously or intermittently. In one aspect, the disperser is configured to disperse the defoamer continuously or intermittently at a predetermined rate. A person skilled in the art can easily determine the appropriate rate for dispersing the condensate. In one aspect, the disperser is disposed on the condenser. In one aspect, the disperser is disposed on each condenser.

[0158] In one aspect, the unit includes a container containing an antifoaming agent. In one aspect, the condenser and the container are arranged in fluid communication. In one aspect, each condenser and the container are arranged in fluid communication. In this way, condensate from the condenser can flow into the container containing the antifoaming agent to combine with the antifoaming agent.

[0159] The invention will now be described with reference to the following non-limiting examples. Example

[0160] Example 1 - Effect of Defoamers on Foaming in Pyrolysis Glucose Pyrolysis Condensate

[0161] 250 mL of condensate was obtained from the pyrolysis glucose cleavage. The condensate contained 8.3 g / L of glyoxal, 12.8 g / L of pyruvic acid (methylglyoxal), 89.3 g / L of glycolaldehyde, 15.2 g / L of formaldehyde and 3.8 g / L of acetol (hydroxyacetone) in aqueous solution.

[0162] 250 mL of condensate was mixed with 12.5 mL of 2-propanol. The resulting mixture contained 5 vol.% 2-propanol based on the total volume of the mixture. 50.0 mL of this mixture was added to a 100 mL stoppered graduated cylinder. The height of the liquid was recorded (i.e., before shaking, see below). The 50.0 mL mixture in the graduated cylinder was shaken 30 times for a total of 10 seconds. The total height of the liquid and any foam was recorded. The height of the foam after shaking for 5 minutes was calculated as the difference between the total height after shaking for 5 minutes and the liquid height (before shaking).

[0163] The above experiment was repeated using 1 vol. % 2-propanol based on the total volume of the mixture (ie, not 5 vol. % 2-propanol).

[0164] The above experiment was also repeated using 20 ppmv of Silfoam SE 47 (i.e. 0.002 wt.% Silfoam SE 47) based on the total volume of the mixture (i.e. instead of 5 vol.% 2-propanol). Silfoam SE 47 is an oil-in-water emulsion based on polydimethylsiloxane and adjuvants with an active ingredient concentration of 17 wt.%.

[0165] The above experiment was also repeated in the absence of 2-propanol.

[0166] Each of the above experiments was repeated three times, and the average height of the foam was calculated.

[0167] The results of the above experiments are as follows Figure 1 Shown are the black bars representing the mean difference between the foam height before and after shaking; and the white bars representing the mean difference between the foam height before and after 5 minutes of shaking.

[0168] The results show that each of the defoamers (2-propanol and Silfoam SE 47) had a positive effect on reducing and / or preventing foam height.

[0169] Example 2- Add defoamer Production Continuous condensation process of pyrolysis glucose pyrolysis condensate layout

[0170] A glucose syrup feed solution (60 wt.% glucose and 40 wt.% water, based on the total weight of the feed solution) is thermally cracked using the system described in US10570078B2. This involves adding the glucose syrup feed solution to a cracking reactor, which thermally cracks the glucose syrup feed solution to form a product gas 101 (comprising a vapor phase oxygenate mixture) comprising C1-C3 oxygenates. The product gas 101 may also include a flushing gas, which may include a fluidizing gas from the cracking reactor.

[0171] The product gas 101 is directed through a first indirect cooling heat exchanger and then through a filter to remove large particles, such as dust. In this particular embodiment, the filter is a surface filter device, although various other gas-solid filters (such as multi-cyclone separators) can be used. Other cooling means can also be used. In some embodiments, the first indirect heat exchanger and filter may not be used.

[0172] like Figure 2 As shown, the product gas 101 leaving the filter undergoes a condensation process. This involves feeding the filtered product gas 101 into a condenser (a cooling tower in this embodiment) 102 containing a packing material 103. A portion of the product gas 101 flowing through the condenser 102 is condensed to form a condensate, which leaves the bottom of the condenser 102 under the action of gravity. The remainder of the product gas 101, which typically includes CO and CO2 (and possible flushing gas), remains in a gaseous state and leaves the top of the condenser 102 as a gas stream 104 through a gas outlet. The temperature of the gas stream 104 leaving the gas outlet is 10°C to 20°C, and the temperature of the condensate leaving the condenser 102 is 40°C to 60°C.

[0173] The condensate leaving the condenser 102 is directed to a pump 105 and then passed through an indirect plate heat exchanger 106, which cools the condensate to a temperature of 10° C. to 20° C. The condensate leaving the heat exchanger 106 is split into a condensate product stream 107A and a condensate recycle stream 107B. The mass ratio of the condensate recycle stream 107B to the condensate product stream 107A can be 10:1 to 20:1, depending on the temperature of the streams 107A and 107B, and is 20:1 in this particular embodiment. The condensate product stream 107A is collected.

[0174] An antifoam 108 is added to the condensate recycle stream 107B. In this example, this is done before the condensate recycle stream 107B is added to the condenser 102 (as discussed below). The antifoam is Silfoam SE 47 as defined in Example 1.

[0175] A mixture of condensate recycle stream 107B and antifoaming agent 108 is added to condenser 102 .

[0176] The mixture of 107B, 108 can be split into at least two streams 109A, 109B. The respective streams 109A, 109B can be added to the condenser 102 at different parts of the condenser 102. For example, the mixture of 107B, 108 can be added at or toward the top of the condenser 102, such as above the packing material 103 (e.g., Figure 2 For example, the mixture of 107B, 108 can be added at or toward the bottom of the condenser, such as below the packing material 103 (e.g., Figure 2 109B).

[0177] The mixture of 107B, 108 (109A) added through the top of the condenser 102 flows downwardly through the packing material 103 under the action of gravity. In this way, the mixture of 107B, 108 (109A) flows countercurrent to the product gas 101, promoting efficient condensation of the product gas 101 in the condenser 102 while preventing excessive foaming. The packing material 103 in the condenser 102 increases the contact area between the mixture of 107B, 108 (109A) and the product gas 101. The packing material is VFF Novalox-25-MAISI 316, although it should be understood that different packing materials can be used. The condenser 102 and the condensate recycle are operated continuously.

[0178] Based on each kilogram of glucose syrup raw material solution added to the thermal cracking condenser, the amount of defoamer 108 added to the condenser is about 0.2 mL. If the defoamer 108 is not used, excessive foam will be formed, which may flood and / or block the condenser 102 and / or other equipment, resulting in reduced performance or equipment failure. The present invention solves this problem.

[0179] It should be understood that the mode in which the defoamer 108 is combined with the condensate can be changed. It should be understood that the condensation process can be carried out in various ways. For example, the mode in which the condensate is recycled and the properties and connectivity of the equipment used can be changed. For example, various other equipment, such as filters and other unit operations, can be used. For example, alternative or additional cooling means can be used, such as adding a coolant to the bottom of the condenser below the packing material. It should also be understood that control and monitoring can be performed in various ways. In this particular embodiment, the liquid level at the bottom of the condenser 102 is a controlled variable. This can be achieved in various ways, such as by adjusting the amount of the 107B, 108 mixture recycled to the condenser 102 (e.g., by adjusting the flow rate of the 107B, 108 mixture recycled to the condenser and / or the ratio of the stream 107A, 107B); and / or by adjusting the amount of the vapor phase oxygenate mixture entering the condenser 102.

[0180] Those skilled in the art will appreciate that the unit operations and any other features between the formation and condensation of the cleavage product 101 may be varied.

[0181] Without departing from the scope and spirit of the present invention, various modifications and variations of the present invention will be apparent to those skilled in the art. Although the present invention has been described in combination with specific preferred embodiments, it should be understood that the claimed invention should not be overly limited to such specific embodiments. In fact, it is apparent to those skilled in the art of chemistry or related fields that various modifications described for implementing the present invention are intended to fall within the scope of the following claims.

[0182] As known to those skilled in the art, the aspects and embodiments mentioned herein can be combined and are at least as given below:

[0183] Embodiment 1. A method for at least partially condensing an oxygenate mixture, the method comprising the steps of:

[0184] (a) providing a vapor phase oxygenate mixture obtained by cracking an aqueous carbohydrate solution;

[0185] (b) at least partially condensing the vapor-phase oxygenate mixture to provide a condensate; and

[0186] (c) combining an antifoaming agent with the condensate.

[0187] Embodiment 2. The method of Embodiment 1, wherein the vapor-phase oxygenate mixture is derived from biomass.

[0188] Embodiment 3. A method according to embodiment 1 or 2, wherein the vapor phase oxygenate mixture comprises C1-C3 oxygenates.

[0189] Embodiment 4. The method according to any one of embodiments 1-3, wherein the carbohydrate in the aqueous carbohydrate solution is selected from monosaccharides, disaccharides, or mixtures thereof.

[0190] Embodiment 5. The method according to any one of embodiments 1-4, wherein the carbohydrate in the aqueous carbohydrate solution is at least glucose.

[0191] Embodiment 6. The method according to any one of embodiments 1-5, wherein the carbohydrates in the aqueous carbohydrate solution comprise at least 40 wt.% monosaccharides based on the total amount of the carbohydrates.

[0192] Embodiment 7. The method according to any one of embodiments 1-6, wherein the defoaming agent comprises one or more active ingredients independently selected from alcohols, ethers, carboxylic acids, esters, polysiloxanes, silica, oils, waxes, and acrylates.

[0193] Embodiment 8. The method according to embodiment 7, wherein the one or more active ingredients are independently selected from alcohols, such as C1-C12 alcohols, or C1-C6 alcohols, or C1-C4 alcohols.

[0194] Embodiment 9. The method of embodiment 7 or 8, wherein the defoaming agent substantially comprises, consists essentially of, or consists of the one or more active ingredients.

[0195] Embodiment 10. The method according to embodiment 7, wherein the one or more active ingredients are independently selected from polysiloxanes, such as polydimethylsiloxane.

[0196] Embodiment 11. The method according to any one of embodiments 7-10, wherein the total active ingredient content of the defoaming agent is 0.0000001 wt.% to 100 wt.% based on the total weight of the defoaming agent.

[0197] Embodiment 12. The method of any one of Embodiments 1-11, wherein combining the defoaming agent and the condensate comprises adding the defoaming agent to the condensate.

[0198] Embodiment 13. The method of embodiment 12, wherein the defoaming agent is added to the condensate at a rate of 0.0000001 mL / h to 200 mL / h.

[0199] Embodiment 14. A method according to any one of Embodiments 1-13, wherein cracking the aqueous carbohydrate solution to provide the vapor phase oxygenate mixture includes adding the aqueous carbohydrate solution to a cracking reactor and thermally cracking the aqueous carbohydrate solution.

[0200] Embodiment 15. The method according to any one of embodiments 1-14, wherein in the combined defoamer and condensate, the mass ratio of the defoamer to the condensate is from 1:1000000 to 1:1.

[0201] Embodiment 16. The method of any one of Embodiments 1-15, wherein in step (b), the vapor-phase oxygenate mixture is at least partially condensed at a temperature of 0°C to 150°C.

[0202] Embodiment 17. The method of any one of Embodiments 1-16, wherein at least partially condensing the vapor-phase oxygenate mixture comprises:

[0203] An input stream comprising the vapor-phase oxygenate mixture is fed through a condenser to provide the condensate and an output stream.

[0204] Embodiment 18. The method of Embodiment 17, wherein at least partially condensing the vapor-phase oxygenate mixture comprises:

[0205] At least a portion of the output stream is recycled into the input stream.

[0206] Embodiment 19. A method according to embodiment 17 or 18, wherein at least partially condensing the vapor-phase oxygen-containing compound mixture includes: splitting the condensate into at least a condensate product stream and a condensate recycle stream, and adding the condensate recycle stream to the condenser.

[0207] Embodiment 20. The method of embodiment 19, wherein combining the defoamer and the condensate comprises adding the defoamer to the condensate recycle stream to form a mixture, and adding the mixture to the condenser.

[0208] Embodiment 21. The method according to Embodiment 20, wherein the temperature of the mixture added to the condenser is 0°C to 30°C.

[0209] Embodiment 22. The method of any one of Embodiments 1-21, wherein the method is a continuous method.

[0210] Embodiment 23. The method according to any one of Embodiments 1-22, comprising the further step of recovering the condensate.

[0211] Embodiment 24. The method of any one of Embodiments 1-23, wherein the cleavage of the aqueous carbohydrate solution is thermal cleavage.

[0212] Embodiment 25. The method according to any one of embodiments 1-24, wherein the oxygen-containing compound mixture obtained directly from the cleavage of the carbohydrate aqueous solution is subjected to step (b).

[0213] Embodiment 26. A system configured to at least partially condense an oxygenate mixture, the system comprising:

[0214] (a) a cleavage reactor configured to cleave an aqueous carbohydrate solution to provide a vapor phase oxygenate mixture;

[0215] (b) a condenser configured to at least partially condense the vapor-phase oxygenate mixture to provide a condensate; and

[0216] (c) a unit configured to combine a defoaming agent with the condensate.

[0217] Embodiment 27. A system according to Embodiment 26, wherein the cracking reactor is selected from: a thermal cracking reactor; and a fluidized bed reactor, such as a bubbling bed reactor, a turbulent bed reactor, or a riser reactor.

[0218] Embodiment 28. A system according to Embodiment 26 or 27, wherein the cracking reactor comprises: a feed inlet; a product outlet; a riser; and a fluidizing gas inlet.

[0219] Embodiment 29. A system according to any one of embodiments 26-28, comprising:

[0220] A separator is configured to separate particulate matter from the vapor-phase oxygenate mixture.

Claims

1. A method for at least partially condensing an oxygen-containing compound mixture, the method comprising: The following steps are involved: (a) providing a vapor phase oxygenate mixture obtained by cracking an aqueous carbohydrate solution; (b) at least partially condensing the vapor-phase oxygenate mixture to provide a condensate; as well as (c) combining an antifoaming agent with the condensate.

2. The process of claim 1 wherein the vapor phase oxygenate mixture is derived from biomass.

3. The process of claim 1 or 2, wherein the vapor phase oxygenate mixture comprises C1-C3 oxygenates.

4. The method according to any one of claims 1 to 3, wherein the carbohydrate in the aqueous carbohydrate solution is selected from monosaccharides, disaccharides, or mixtures thereof.

5. The method according to any one of claims 1 to 4, wherein the carbohydrates in the aqueous carbohydrate solution comprise at least 40 wt.% of monosaccharides based on the total amount of carbohydrates.

6. The method according to any one of claims 1 to 5, wherein the defoaming agent comprises one or more active ingredients independently selected from alcohols, ethers, carboxylic acids, esters, polysiloxanes, silica, oils, waxes, and acrylates. 7 . The method according to claim 6 , wherein the total active ingredient content of the defoaming agent is 0.0000001 wt. % to 100 wt. % based on the total weight of the defoaming agent.

8. The method of any one of claims 1-7, wherein combining the antifoaming agent and the condensate comprises adding the antifoaming agent to the condensate.

9. The method according to claim 8, wherein the defoaming agent is added to the condensate at a rate of 0.0000001 mL / h to 200 mL / h.

10. The method of any one of claims 1-9, wherein cracking the aqueous carbohydrate solution to provide a vapor phase oxygenate mixture comprises adding the aqueous carbohydrate solution to a cracking reactor and subjecting the aqueous carbohydrate solution to thermal cracking.

11. The method according to any one of claims 1 to 10, wherein in the combined defoamer and condensate, the mass ratio of the defoamer to the condensate is from 1:1000000 to 1:

1.

12. The process according to any one of claims 1 to 11, wherein in step (b), the vapor phase oxygenate mixture is at least partially condensed at a temperature of 0°C to 150°C.

13. The process according to any one of claims 1 to 12, wherein the vapor phase oxygenate mixture is at least partially condensed include: An input stream comprising the vapor-phase oxygenate mixture is fed through a condenser to provide a condensate and an output stream.

14. The process of claim 13, wherein the vapor phase oxygenate mixture is at least partially condensed include: At least a portion of the output stream is recycled into the input stream.

15. The process according to claim 13 or 14, wherein the vapor phase oxygenate mixture is at least partially condensed include: The condensate is split into at least a condensate product stream and a condensate recycle stream, and the condensate recycle stream is fed to the condenser.

16. The method according to claim 15, wherein the defoaming agent and the condensate are combined include: The antifoaming agent is added to the condensate recycle stream to form a mixture, and the mixture is added to the condenser.

17. The process according to any one of claims 1 to 16, wherein the oxygenate mixture obtained directly from the cleavage of an aqueous carbohydrate solution is subjected to step (b).

18. A system configured to at least partially condense an oxygenate mixture, the system include: (a) a cleavage reactor configured to cleave an aqueous carbohydrate solution to provide a vapor phase oxygenate mixture; (b) a condenser configured to at least partially condense the vapor-phase oxygenate mixture to provide a condensate; and (c) a unit configured to combine an antifoaming agent with the condensate.

19. The system of claim 18, wherein the cleavage reactor is selected from: a thermal cleavage reactor; a fluidized bed reactor, such as a bubbling bed reactor, a turbulent bed reactor, or a riser reactor.

20. The system of claim 18 or 19, wherein the cleavage reactor include: Feed inlet; Product outlet; riser; and a fluidizing gas inlet.

21. The system according to any one of claims 18 to 20, include: A separator is configured to separate particulate matter from the vapor-phase oxygenate mixture.

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