Glycol compositions

Abstract

The present disclosure provides a composition comprising monopropylene glycol, monoethylene glycol, 1,2-butanediol, 2,3-pentanediol and water. The compositions of the disclosure have desirable properties and can be used as a low carbon footprint alternative to fossil-based glycol compositions in various applications.

Description

[0001] GLYCOL COMPOSITIONS

[0002] FIELD

[0003] The present disclosure relates to glycol compositions and uses thereof. More particularly, the disclosure relates to aqueous compositions which comprise a specific combination of glycols. Compositions described herein can be used as a low carbon footprint alternative to fossil-based glycol compositions in various applications.

[0004] BACKGROUND

[0005] There is great worldwide interest in mitigating climate change and minimising environmental impact. In response to this need, there is a growing demand for innovative solutions to reduce carbon footprints across industries worldwide. With the increasing awareness of the detrimental effects of fossil-based petrochemicals and greenhouse gas emissions, there is a pressing need for sustainable alternatives.

[0006] Glycols such as monopropylene glycol and monoethylene glycol are important raw materials that are used in a multitude of applications and industrial processes. In particular, glycols are used in the production of polymers such as polyesters and polyurethanes. Glycols are made on an industrial scale from petrochemicals derived from crude oil, but due to environmental concerns there is a strong interest in obtaining glycols from renewable resources. In this regard, it is known that sugars contained in plant mass can be converted to glycols by catalytic hydrogenolysis, the process producing a mixture of compounds from which the desired products can be recovered by distillation. However, the recovery of monopropylene glycol and monoethylene glycol in high purity can be challenging.

[0007] There remains a need for further glycol compositions. In particular, there is a need for glycol compositions which exhibit desirable properties and can be prepared from renewable resources in a facile manner. These and other needs are met by the present disclosure. SUMMARY

[0008] In one aspect, the present disclosure provides a composition comprising monopropylene glycol, monoethylene glycol, 1,2-butanediol, 2,3-pentanediol and water.

[0009] In other aspects, the disclosure is directed to uses and methods involving the compositions described herein. The disclosure is also directed to processes for preparing the compositions, as well as compositions obtainable by said processes.

[0010] DETAILED DESCRIPTION

[0011] Glycol Compositions

[0012] The compositions of the disclosure are aqueous compositions which comprise a mixture of glycols. The term "glycol" as used herein refers to an aliphatic compound containing two hydroxy groups attached to different carbon atoms, wherein said carbon atoms may or may not be adjacent.

[0013] The compositions comprise water and the following glycols: monopropylene glycol (also known as MPG, 1,2-propanediol or propane-1, 2-diol), monoethylene glycol (also known as MEG, 1,2-ethanediol or ethane-l,2-diol), 1,2-butanediol (also known as butane-l,2-diol), and 2,3-pentanediol (also known as pentane-2,3-diol).

[0014] In an embodiment, the composition comprises monopropylene glycol in an amount of from 40% to 70% by weight of the composition. In a particular embodiment, the composition comprises monopropylene glycol in an amount of from 50% to 60% by weight of the composition.

[0015] In an embodiment, the composition comprises monoethylene glycol in an amount of from 5% to 40% by weight of the composition, for example an amount of from 5% to 30% by weight of the composition. In a particular embodiment, the composition comprises monoethylene glycol in an amount of from 5% to 25% by weight of the composition, for example an amount of from 10% to 25% by weight of the composition.

[0016] In an embodiment, the composition comprises 1,2-butanediol in an amount of from 5% to 25% by weight of the composition. In a particular embodiment, the composition comprises 1,2-butanediol in an amount of from 10% to 25% by weight of the composition, for example an amount of from 10% to 20% by weight of the composition.

[0017] In an embodiment, the composition comprises 2,3-pentanediol in an amount of from 0.1% to 5% by weight of the composition. In a particular embodiment, the composition comprises 2,3-pentanediol in an amount of from 0.1% to 2% by weight of the composition, for example an amount of from 0.1% to 1% by weight of the composition.

[0018] In an embodiment, the composition comprises water in an amount of from 0.001% to 10% by weight of the composition, for example an amount of from 0.01% to 10% by weight of the composition. In an embodiment, the composition comprises water in an amount of from 0.1% to 10% by weight of the composition.

[0019] In an embodiment, the composition comprises water in an amount of from 0.001% to 5% by weight of the composition, for example an amount of from 0.01% to 5% by weight of the composition. In a particular embodiment, the composition comprises water in an amount of from 0.1% to 5% by weight of the composition, for example an amount of from 0.1% to 4% by weight of the composition.

[0020] In an embodiment, the composition comprises monopropylene glycol in an amount of from 40% to 70% by weight of the composition; monoethylene glycol in an amount of from 5% to 40% by weight of the composition; 1,2-butanediol in an amount of from 5% to 25% by weight of the composition; 2,3-pentanediol in an amount of from 0.1% to 5% by weight of the composition; and water in an amount of from 0.1% to 10% by weight of the composition. In an embodiment, the composition comprises monopropylene glycol in an amount of from 40% to 70% by weight of the composition; monoethylene glycol in an amount of from 5% to 25% by weight of the composition; 1,2-butanediol in an amount of from 5% to 25% by weight of the composition; 2,3-pentanediol in an amount of from 0.1% to 5% by weight of the composition; and water in an amount of from 0.1% to 10% by weight of the composition.

[0021] In an embodiment, the composition comprises monopropylene glycol in an amount of from 50% to 60% by weight of the composition; monoethylene glycol in an amount of from 5% to 30% by weight of the composition; 1,2-butanediol in an amount of from 10% to 25% by weight of the composition; 2,3-pentanediol in an amount of from 0.1% to 2% by weight of the composition; and water in an amount of from 0.1% to 5% by weight of the composition.

[0022] In an embodiment, the composition comprises monopropylene glycol in an amount of from 50% to 60% by weight of the composition; monoethylene glycol in an amount of from 10% to 25% by weight of the composition; 1,2-butanediol in an amount of from 10% to 20% by weight of the composition; 2,3-pentanediol in an amount of from 0.1% to 2% by weight of the composition; and water in an amount of from 0.1% to 5% by weight of the composition.

[0023] In an embodiment, the composition further comprises 2,3-butanediol (also known as butane-2,3-diol). In an embodiment, the composition comprises 2,3-butanediol in an amount of from 0.1% to 5% by weight of the composition, for example an amount of from 0.5% to 4.5% by weight of the composition. In a particular embodiment, the composition comprises 2,3-butanediol in an amount of from 0.1% to 2% by weight of the composition, for example an amount of from 0.1% to 1% by weight of the composition.

[0024] In an embodiment, the composition comprises monopropylene glycol in an amount of from 40% to 70% by weight of the composition; monoethylene glycol in an amount of from 5% to 40% by weight of the composition; 1,2-butanediol in an amount of from 5% to 25% by weight of the composition; 2,3-pentanediol in an amount of from 0.1% to 5% by weight of the composition; 2,3-butanediol in an amount of from 0.1% to 5% by weight of the composition; and water in an amount of from 0.1% to 10% by weight of the composition.

[0025] In an embodiment, the composition comprises monopropylene glycol in an amount of from 40% to 70% by weight of the composition; monoethylene glycol in an amount of from 5% to 25% by weight of the composition; 1,2-butanediol in an amount of from 5% to 25% by weight of the composition; 2,3-pentanediol in an amount of from 0.1% to 5% by weight of the composition; 2,3-butanediol in an amount of from 0.1% to 5% by weight of the composition; and water in an amount of from 0.1% to 10% by weight of the composition.

[0026] In an embodiment, the composition comprises monopropylene glycol in an amount of from 50% to 60% by weight of the composition; monoethylene glycol in an amount of from 5% to 30% by weight of the composition; 1,2-butanediol in an amount of from 10% to 25% by weight of the composition; 2,3-pentanediol in an amount of from 0.1% to 2% by weight of the composition; 2,3-butanediol in an amount of from 0.1% to 2% by weight of the composition; and water in an amount of from 0.1% to 5% by weight of the composition.

[0027] In an embodiment, the composition comprises monopropylene glycol in an amount of from 50% to 60% by weight of the composition; monoethylene glycol in an amount of from 10% to 25% by weight of the composition; 1,2-butanediol in an amount of from 10% to 20% by weight of the composition; 2,3-pentanediol in an amount of from 0.1% to 2% by weight of the composition; 2,3-butanediol in an amount of from 0.1% to 2% by weight of the composition; and water in an amount of from 0.1% to 5% by weight of the composition.

[0028] Preferably, the composition is a bio-based composition that is obtained from a renewable resource. The term "bio-based" as used herein refers to a composition or compound having a percent modern carbon (pMC) of at least 80% as measured using the ASTM D6866-21 test method. This test method is a standard method for experimentally determining the biobased carbon content of solid, liquid and gaseous samples using radiocarbon analysis, and it distinguishes carbon resulting from contemporary bio-based materials versus those derived from fossil-based materials. Preferably, therefore, the composition has a pMC of at least 80% as measured using the ASTM D6866-21 test method. In particular, it is preferred that the composition has a pMC of at least 90%, more preferably 95%. More preferably, the composition has a pMC of at least 99%, for example 100%.

[0029] In an embodiment, the composition is a bio-based composition wherein each of the monopropylene glycol, monoethylene glycol, 1,2-butanediol and 2,3-pentanediol is a biobased compound. In an embodiment, the composition is a bio-based composition in which all of the carbon-containing compounds in the composition are bio-based.

[0030] In an embodiment, the composition is a bio-based composition that is prepared from a wood-based raw material, such as hardwood or softwood. The wood-based raw material may originate from, e.g., pine, poplar, beech, aspen, spruce, eucalyptus, ash, oak, maple, chestnut, willow or birch. The wood-based raw material may also be any combination or mixture of these.

[0031] Preparation Processes

[0032] The compositions of the disclosure may be obtained by any suitable means known in the art. For example, the compositions may be prepared by mixing water and the glycol compounds in the desired quantities.

[0033] Preferably, however, the compositions are obtained via a process comprising catalytic hydrogenolysis of a carbohydrate composition. More particularly, it is preferred that the compositions are obtained by a process which comprises contacting a carbohydrate composition with hydrogen in a reactor in the presence of water and a catalyst under conditions such that the carbohydrate composition undergoes catalytic hydrogenolysis to produce an aqueous mixture comprising monopropylene glycol, monoethylene glycol, 1,2- butanediol and 2,3-pentanediol. In order to prepare the compositions of the disclosure, it is preferred that a carbohydrate composition comprising a particular combination of sugars is employed. Preferably, the carbohydrate composition comprises glucose, xylose and one or more sugars selected from galactose, arabinose, mannose and fructose. More preferably, the carbohydrate composition comprises each of glucose, xylose, galactose, arabinose, mannose and fructose.

[0034] The amounts of the sugars in the carbohydrate composition may be expressed as a percentage by weight of the total dry matter content of the carbohydrate composition. The expression "total dry matter content" as used herein refers to the total amount of solids including suspended solids and soluble or dissolved solids in the carbohydrate composition. The total dry matter content may be determined after removing the liquid from a sample followed by drying at a temperature of 105 °C for 24 hours. The effectiveness of the liquid removal may be assured by weighing the sample, drying for a further two hours at the specified temperature, and reweighing the sample. If the measured weights are the same, the drying has been complete, and the total weight may be recorded.

[0035] In an embodiment, the carbohydrate composition comprises from 85% to 97% by weight of glucose; from 1% to 10% by weight of xylose; from 0.1% to 2% by weight of galactose; from 0.1% to 2% by weight of arabinose; from 0.1% to 2% by weight of mannose; and from 0.1% to 5% by weight of fructose, wherein said amounts are based on the total dry matter content of the carbohydrate composition.

[0036] In a preferred embodiment, the carbohydrate composition comprises from 90% to 95% by weight of glucose; from 4% to 8% by weight of xylose; from 0.1% to 1% by weight of galactose; from 0.1% to 1% by weight of arabinose; from 0.1% to 1% by weight of mannose; and from 0.1% to 2% by weight of fructose, wherein said amounts are based on the total dry matter content of the carbohydrate composition.

[0037] As is known in the art, sugars may exist in monomeric and oligomeric forms. The term "monomeric" as used herein refers to a sugar molecule that is not coupled or connected to any other sugar molecule(s). Monomeric sugars are also known as monosaccharides. The term "oligomeric" as used herein refers to a sugar molecule consisting of two or more monomers coupled or connected to each other. Examples of oligomeric sugars include disaccharides and trisaccharides.

[0038] Preferably, the carbohydrate composition has a total monomeric sugar content of at least 90% by weight based on the total dry matter content of the carbohydrate composition. More preferably, the monomeric sugar content of the carbohydrate composition is at least 94% by weight, for example at least 95% by weight, based on the total dry matter content of the carbohydrate composition.

[0039] The monomeric and oligomeric sugars in the carbohydrate composition may be determined both qualitatively and quantitatively by high-performance liquid chromatography (HPLC) by comparing to standard samples. Examples of suitable methods can be found in e.g. Sluiter, A., et aL, "Determination of sugars, byproducts, and degradation products in liquid fraction process samples", Technical Report, National Renewable Energy Laboratory, 2008, and Sluiter, A., et aL, "Determination of Structural Carbohydrates and Lignin in Biomass", Technical Report, National Renewable Energy Laboratory, revised 2012.

[0040] Preferably, the carbohydrate composition is a bio-based composition. For example, the carbohydrate composition may be obtained from a plant-based raw material.

[0041] More preferably, the carbohydrate composition is obtained from a wood-based raw material, such as hardwood or softwood. In general, wood-based raw materials are composed essentially of cellulose, hemicellulose, lignin, and extractives. Cellulose is a polysaccharide consisting of a chain of glucose units. Hemicellulose comprises polysaccharides, such as xylan, mannan, and glucan.

[0042] The wood-based raw material may originate from, e.g., pine, poplar, beech, aspen, spruce, eucalyptus, ash, oak, maple, chestnut, willow or birch. The wood-based raw material may also be any combination or mixture of these. When a wood-based raw material is used as the carbohydrate source, the carbohydrate composition may be prepared by a process comprising: subjecting a wood-based feedstock comprising wood chips to at least one pretreatment to form a liquid fraction and a fraction comprising solid cellulose particles; and subjecting the fraction comprising solid cellulose particles to enzymatic hydrolysis to form a lignin fraction and a carbohydrate fraction. The carbohydrate fraction may be optionally purified and then used as the carbohydrate composition in the catalytic hydrogenolysis process.

[0043] The expressions "pretreating" and "pretreatment" as used herein refer to a process conducted to convert a wood-based feedstock to a fraction comprising solid cellulose particles. As a result of the pretreatment, in addition to the fraction comprising solid cellulose particles, a liquid fraction may be formed. The liquid fraction may be separated from the fraction comprising solid cellulose particles. The fraction comprising solid cellulose particles may further include an amount of lignocellulose particles as well as lignin particles in free form. Lignocellulose comprises lignin chemically bonded to the cellulose particles.

[0044] The wood-based feedstock may be provided by subjecting a wood-based raw material to a mechanical treatment selected from debarking, chipping, dividing, cutting, beating, grinding, crushing, splitting, screening, and / or washing to form the wood-based feedstock. Alternatively, the wood-based feedstock may be purchased.

[0045] Pretreatment of the wood-based feedstock may comprise one or more different pretreatment processes. During the different pretreatment processes the wood-based feedstock as such changes. The aim of the at least one pretreatment processes is to form a fraction comprising solid cellulose particles for further processing.

[0046] The pretreatment may comprise subjecting the wood-based feedstock to pre-steaming. In particular, the pretreatment may comprise subjecting the wood-based feedstock received from the mechanical treatment to pre-steaming. The pretreatment may comprise an impregnation treatment and / or a steam explosion and comprise, before subjecting the wood-based feedstock to impregnation treatment and / or to steam explosion, subjecting the wood-based feedstock to pre-steaming, wherein the pre-steaming of the wood-based feedstock is carried out with steam having a temperature of from 100 to 130 °C at atmospheric pressure. During the pre-steaming the wood-based feedstock is treated with steam of low pressure. The pre-steaming may be also carried out with steam having a temperature of below 100 °C, or below 98 °C, or below 95 °C. The pre-steaming has the added utility of reducing or removing air from inside of the wood-based feedstock.

[0047] The pre-steaming may take place in at least one pre-steaming reactor. In one embodiment, a pre-steaming reactor is operationally arranged before the impregnation reactor and / or the pressurised reactor and configured to subject the wood-based feedstock to presteaming with steam having a temperature of from 100 to 130 °C at atmospheric pressure.

[0048] Pretreatment may also comprise subjecting the wood-based feedstock to at least one impregnation treatment with an impregnation liquid. The impregnation treatment may be carried out to the wood-based feedstock received from the mechanical treatment and / or from the pre-steaming. The pretreatment may comprise, before subjecting to the steam explosion, subjecting the wood-based feedstock to at least one impregnation treatment with an impregnation liquid selected from water, at least one acid, at least one alkali, at least one alcohol, or any combination or mixture thereof.

[0049] The wood-based feedstock may be transferred from the mechanical treatment and / or from the pre-steaming to the impregnation treatment with a feeder. The feeder may be a screw feeder, such as a plug screw feeder. The feeder may compress the wood-based feedstock during the transfer. When the wood-based feedstock enters the impregnation treatment, it may become expanded and absorb the impregnation liquid.

[0050] The impregnation liquid may comprise water, at least one acid, at least one alkali, at least one alcohol, or any combination or mixture thereof. The at least one acid may be selected from a group consisting of inorganic acids, such as sulphuric acid (H2SO4), nitric acid, phosphoric acid; organic acids, such as acetic acid, lactic acid, formic acid, carbonic acid; and any combination or mixture thereof. In one embodiment, the impregnation liquid comprises sulphuric acid, e.g. dilute sulphuric acid. The concentration of the acid may be from 0.3% to 5.0% by weight, from 0.5% to 3.0% by weight, from 0.6% to 2.5% by weight, from 0.7% to 1.9% by weight, or from 1.0% to 1.6% by weight. The impregnation liquid may act as a catalyst for the hydrolysis of the hemicellulose in the wood-based feedstock. In one embodiment, the impregnation is conducted by using only water, i.e. by autohydrolysis. In one embodiment, the wood-based feedstock may be impregnated through alkaline hydrolysis. NaOH and CazfOH can be mentioned as examples to be used as the alkali in the alkaline hydrolysis.

[0051] The impregnation treatment may be performed using an impregnation reactor configured to subject the wood-based feedstock to at least one impregnation treatment with an impregnation liquid. The impregnation reactor may be configured to subject the woodbased feedstock to at least one impregnation treatment with an impregnation liquid selected from water, at least one acid, at least one alcohol, or any combination or mixture thereof. The impregnation treatment may thus be conducted in at least one impregnation reactor or vessel. In one embodiment, two or more impregnation reactors are used.

[0052] The transfer from one impregnation reactor to another impregnation reactor may be carried out with a feeder, such as a screw feeder. The feeder may together with steam even out liquid concentration differences within the wood chips whereby the impregnation liquid may more readily penetrate the wood chips.

[0053] The impregnation treatment may be carried out by conveying the wood-based feedstock through at least one impregnation reactor, i.e. the wood-based feedstock may be transferred into the impregnation reactor, interspersed inside the impregnation reactor, and transferred out of the impregnation reactor such that the wood-based feedstock is homogenously impregnated with the impregnation liquid. The impregnation treatment may be carried out as a batch process or in a continuous manner.

[0054] The residence time of the wood-based feedstock in an impregnation reactor, i.e. the time during which the wood-based feedstock is in contact with the impregnation liquid, may be from 5 seconds to 5 minutes, or from 0.5 to 3 minutes, or about 1 minute. The temperature of the impregnation liquid may be, for example, from 20 to 99 °C, or from 40 to 95 °C, or from 60 to 90 °C. Maintaining the temperature of the impregnation liquid below 100 °C has the added utility of hindering or reducing hemicellulose from dissolving.

[0055] After the impregnation treatment, the wood-based feedstock may be stored in e.g. a storage tank or a silo for a predetermined period of time to allow the impregnation liquid absorbed into the wood-based feedstock to stabilize. This predetermined period of time may be from 15 to 60 minutes, for example about 30 minutes.

[0056] Pretreatment may comprise subjecting the wood-based feedstock to steam explosion. The term "steam explosion" as used herein refers to a process of hemihydrolysis in which the wood-based feedstock is treated in a reactor with steam under conditions which result in a sudden, explosive decompression of the wood-based feedstock that causes rupture of the fiber structure of the wood-based feedstock.

[0057] The wood-based feedstock from the mechanical treatment, the pre-steaming step, and / or from the impregnation treatment may be subjected to steam explosion. In one embodiment, pretreatment comprises at least one of mechanical treatment of wood-based material to form wood-based feedstock, pre-steaming of the wood-based feedstock, impregnation treatment of the wood-based feedstock, and steam explosion of the woodbased feedstock. In one embodiment, pretreatment comprises mechanical treatment of wood-based material to form a wood-based feedstock, pre-steaming of the wood-based feedstock, impregnation treatment of the wood-based feedstock, and steam explosion of the wood-based feedstock. The wood-based feedstock can be stored in e.g. chip bins or silos between the different treatments. Alternatively, the wood-based feedstock may be conveyed from one treatment to the other in a continuous manner.

[0058] The steam explosion process may be conducted in a pressurized reactor. The steam explosion may be carried out in the pressurized reactor by treating the wood-based feedstock with steam having a temperature of from 130 to 240 °C under a pressure of from 0.17 to 3.25 MPaG followed by a sudden, explosive decompression of the wood-based feedstock. The wood-based feedstock may be treated with the steam for e.g. from 1 to 20 minutes, from 2 to 16 minutes, from 4 to 13 minutes, from 3 to 10 minutes, or from 3 to 8 minutes, before the sudden, explosive decompression of the wood-based feedstock.

[0059] The wood-based feedstock may be introduced into the pressurized reactor with a compressing conveyor, e.g. a screw feeder. During transportation with the screw feeder, if used, part of the impregnation liquid absorbed by the wood-based feedstock is removed as a pressate while some of it remains in the feedstock. The wood-based feedstock may be introduced into the pressurized reactor along with steam and / or gas. The pressure of the pressurized reactor can be controlled by the addition of steam. The pressurized reactor may operate in a continuous manner or as a batch process.

[0060] The wood-based feedstock, for example the wood-based feedstock that has been subjected to an impregnation treatment, may be introduced into the pressurized reactor at a temperature of from 25 to 140 °C. The residence time of the wood-based feedstock in the pressurized reactor may be from 0.5 to 120 minutes. The term "residence time" as used in this context refers to the time between the wood-based feedstock being introduced into or entering the pressurized reactor and the wood-based feedstock being exited or discharged from the sa e.

[0061] As a result of the hemihydrolysis of the wood-based feedstock caused by the steam treatment in the reactor, the hemicellulose present in the wood-based feedstock may become hydrolyzed or degraded into, e.g., xylose oligomers and / or monomers. Thus, steam explosion of the wood-based feedstock may result in the formation of an output stream. The output stream from the steam explosion may be subjected to steam separation. The output stream from the steam explosion may be mixed or combined with a liquid. The output stream of the steam explosion may be mixed with a liquid to form a liquid fraction and a fraction comprising solid cellulose particles. The liquid may be pure water or water containing C5 sugars. The water containing C5 sugars may be recycled water from separation and / or washing the fraction comprising solid cellulose particles before enzymatic hydrolysis. The output stream may be mixed with the liquid and the resulting mass may be homogenized mechanically to break up agglomerates.

[0062] The method may comprise separating and recovering the liquid fraction and the fraction comprising solid cellulose particles. The separated or recovered fraction comprising solid cellulose particles may be washed before being subjected to enzymatic hydrolysis. The fraction comprising solid cellulose particles may be diluted with water and / or other liquid containing at least soluble carbohydrates.

[0063] The above-described pre-treatments can be performed alone or in combination. The pretreated material can then be mixed with a suitable liquid (e.g. water) to form a slurry comprising solid cellulose particles. The fraction comprising solid cellulose particles may be separated from the liquid fraction by a suitable separation method, e.g. by a solid-liquid separation.

[0064] Enzymatic hydrolysis of the fraction comprising solid cellulose particles may be carried out at a temperature of from 30 to 70 °C, from 35 to 65 °C, from 40 to 60 °C, from 45 to 55 °C, or from 48 to 53 °C. The enzymatic hydrolysis may be carried out at atmospheric pressure. The pH of the fraction comprising solid cellulose particles may be kept at a pH value of from 3.5 to 6.5, from 4.0 to 6.0, or from 4.5 to 5.5. The pH of the fraction comprising solid cellulose particles can be adjusted with the addition of alkali and / or acid. The enzymatic hydrolysis may be continued for a time period of from 20 to 120 h, from 30 to 90 h, or from 40 to 80 h. The enzymatic hydrolysis may be carried out in a continuous manner or as a batch-type process or as a combination of a continuous and a batch-type process.

[0065] In one embodiment, the enzymatic hydrolysis is carried out at a temperature of from 30 to 70 °C, from 35 to 65 °C, from 40 to 60 °C, from 45 to 55 °C, or from 48 to 53 °C while keeping the pH of the fraction comprising solid cellulose particles at a pH value of from 3.5 to 6.5, from 4.0 to 6.0, or from 4.5 to 5.5, and wherein the enzymatic hydrolysis is allowed to continue for from 20 to 120 h, from 30 to 90 h, or from 40 to 80 h. In one embodiment, the enzymatic hydrolysis may be carried out as a one-step hydrolysis process, wherein the fraction comprising solid cellulose particles is subjected to enzymatic hydrolysis in at least one first hydrolysis reactor. After the hydrolysis, the hydrolysis product, i.e. the hydrolysate, may be subjected to a separation, wherein the solid lignin fraction, which in addition to lignin may also comprise non-hydrolyzed cellulose, is separated from the liquid carbohydrate fraction. The one-step hydrolysis process may be carried out as a batch process comprising e.g. several reactors working in parallel, wherein each reactor may receive a part of the fraction comprising solid cellulose particles. Further, separate parallel lines with parallel reactors may be used.

[0066] In one embodiment, the enzymatic hydrolysis may be carried out as a two-step hydrolysis process or as a multi-step hydrolysis process. In the two-step hydrolysis process or in the multi-step hydrolysis process the fraction comprising solid cellulose particles may first be subjected to a first enzymatic hydrolysis in at least one first hydrolysis reactor. Then the formed liquid carbohydrate fraction may be separated from the solid lignin fraction, which may also comprise unhydrolyzed cellulose. The solid fraction may then be subjected to a second or any latter enzymatic hydrolysis, e.g. in at least one second hydrolysis reactor. At least one of the first enzymatic hydrolysis and the second or any latter enzymatic hydrolysis may be carried out as a batch process or as a continuous process comprising e.g. one or several reactors working in parallel. After the second or any latter enzymatic hydrolysis, the hydrolysis product, i.e. the hydrolysate, may be subjected to separation, wherein the solid lignin fraction is separated from the liquid carbohydrate fraction.

[0067] The reaction time in the first hydrolysis reactor may be from 8 to 72 hours. The reaction time in the second and / or any latter hydrolysis reactor may be from 8 to 72 hours.

[0068] The enzymes are catalysts for the enzymatic hydrolysis. The enzymatic reaction decreases the pH and by shortening the length of the cellulose fibers it may also decrease the viscosity. Subjecting the fraction comprising solid cellulose particles to enzymatic hydrolysis may result in cellulose being transformed into sugar monomers with enzymes. Lignin present in the fraction comprising solid cellulose particles may remain essentially in solid form.

[0069] At least one enzyme is used for carrying out the enzymatic hydrolysis. The at least one enzyme may be selected from a group consisting of cellulases, hemicellulases, laccases, and lignolytic peroxidases. Cellulases are multi-protein complexes consisting of synergistic enzymes with different specific activities that can be divided into exo- and endo-cellulases (glucanase) and |3-glucosidase (cellobiose). The enzymes may be either commercially available cellulase mixes or manufactured on-site.

[0070] Cellulose is an insoluble linear polymer of repeating glucose units linked by 0-1-4-glucosidic bonds. During the enzymatic hydrolysis, cellulose chains are broken by means of breaking at least one [3-1-4-glucosidic bond.

[0071] Enzymatic hydrolysis may result in the formation of a lignin fraction and a carbohydrate fraction. In one embodiment, the lignin fraction is in solid form. In one embodiment, the carbohydrate fraction is in liquid form. The lignin fraction and the carbohydrate fraction formed may be separated and recovered before conducting the catalytic conversion.

[0072] Separation(s) conducted during the preparation process may be carried out by filtration and / or by centrifugal treatment. The filtration may be vacuum filtration, filtration based on the use of underpressure, filtration based on the use of overpressure, or filter pressing.

[0073] The carbohydrate fraction recovered from enzymatic hydrolysis may be purified. The purification of the carbohydrate fraction may be carried out by using at least one of the following: membrane filtration, crystallization, sterilization, pasteurization, evaporation, chromatography, ion exchanging, by active carbon. Purification of the carbohydrate fraction has the added utility of providing a desired target quality of sugars.

[0074] While it is preferred that the carbohydrate composition is obtained from a wood-based raw material, it will be appreciated that sugars obtained from other sources may also be used in the catalytic hydrogenolysis process. For instance, a carbohydrate composition derived from corn starch may be used.

[0075] As noted above, the catalytic conversion process involves contacting the carbohydrate composition with hydrogen in a reactor in the presence of water and a catalyst under conditions such that the carbohydrate composition undergoes catalytic hydrogenolysis to produce an aqueous mixture comprising monopropylene glycol, monoethylene glycol, 1,2- butanediol and 2,3-pentanediol.

[0076] The catalytic conversion may be carried out in the presence of a catalyst system comprising one or more catalysts. In one embodiment, the catalyst system comprises or consists of a first catalyst. In one embodiment, the catalyst system comprises or consists of at least a first catalyst and at least a second catalyst. In one embodiment, the catalyst system comprises or consists of a first catalyst and a second catalyst. The first catalyst may be a heterogenous, solid catalyst. The second catalyst may be a homogenous catalyst. In one embodiment, the first and second catalysts may be heterogenous catalysts e.g. supported on a carrier.

[0077] The first catalyst may comprise an active metal component selected from Group 8, Group 9, or Group 10 of the IUPAC Periodic Table of Elements, such as iron, cobalt, nickel, ruthenium, rhodium, palladium, iridium, platinum, or a mixture thereof. In one embodiment, the first catalyst comprises or consists of a heterogeneous Ni-alloy, such as Raney Nickel. The active metal component of the first catalyst may be supported by a carrier comprising activated carbon, alumina, silica, silicon carbide, zirconia, zinc oxide, titanium dioxide, or a mixture thereof. The active metal component of the first catalyst may account for 0.05% to 70% by weight of the total weight of the catalyst.

[0078] The second catalyst may comprise at least one active component selected from tungsten oxide, tungsten sulfide, tungsten hydroxide, tungsten bronze oxide, tungsten acid, tungstate, metatungstate acid, metatungstate, paratungstate acid, para-tungstate, peroxotungstic acid, pertungstate, and hetero-polyacid containing tungsten. In one embodiment, the second catalyst comprises or consists of homogenous sodium tungstate.

[0079] The first catalyst may be active in the hydrogenation. The second catalyst may be active in cracking (also referred to as retro-aldol condensation).

[0080] In an embodiment the second catalyst is a homogenous catalyst and the second catalyst may be recovered, purified and recycled to be reused in the catalytic conversion.

[0081] The catalytic conversion may be carried out at a temperature of from 120 to 300 °C, from 180 to 270 °C, or from 230 to 270 °C. The initial pressure at room temperature may be from 1 to 15 MPa, or from 9 to 12.5 MPa. The catalytic conversion may be carried out in a continuous manner. The time that the feedstock is subjected to catalytic conversion may be from 5 minutes to 3 hours, preferably from 30 minutes to 2.5 hours.

[0082] The catalytic conversion may take place in a conversion reactor, such as a fixed bed or a slurry reactor. The catalytic conversion may take place as a slurry reaction. The hydrogen and the feedstock may be added to the reactor separately or as a combined feed. The second catalyst being in liquid form may be added to the reactor separately from or together with the feedstock. The first catalyst may be provided to the reactor separately from the feedstock, preferably before the feedstock is fed to the reactor. Liquid and gaseous reaction products may be removed from the reactor. The reaction products may be cooled and depressurized. After depressurizing, the gaseous products may be conducted to gas / liquid separation to separate the desired product in liquid form.

[0083] The catalytic conversion results in hydrogenolysis of the carbohydrate composition such that an aqueous mixture comprising monopropylene glycol, monoethylene glycol, 1,2- butanediol and 2,3-pentanediol is formed. Especially if a particular target level of one or more of the glycols is desired, the aqueous mixture may be subjected to further processing in order to obtain the desired composition. In an embodiment, the aqueous mixture is subjected to a separation technique in order to produce the desired composition. The separation technique may be selected from adsorption, evaporation, distillation, extractive distillation, azeotrope distillation, vacuum distillation, atmospheric distillation, membrane separation, filtration, reactive purification or a combination of two or more thereof.

[0084] In an embodiment, the desired composition is recovered from the aqueous mixture by distillation. In a preferred embodiment, the aqueous mixture is subjected to a distillation procedure in which a portion of the monoethylene glycol present in the aqueous mixture is removed as a purified monoethylene glycol fraction and the desired composition is simultaneously recovered as a separate fraction.

[0085] The distillation is carried out in at least one distillation column. The aqueous mixture may be fed into the distillation column in the form of a liquid or as a steam or vapor or a mixture thereof. Purified monoethylene glycol may be removed from the distillation column as a side stream, preferably taken from the bottom of the distillation column, while the composition of the disclosure may be recovered as a top stream from the distillation column.

[0086] The distillation may be carried out at a temperature of from 50 to 250 °C, for example from 100 to 200 °C. The distillation may be carried out at a pressure of at least 0.1 kPa, or at least 10 kPa, or at least 50 kPa. The pressure may be at most 400 kPa, or at most 200 kPa, or at most 120 kPa. It will be clear to a skilled person how to vary the temperature and pressure in relation to each other in order to achieve suitable conditions.

[0087] In a further aspect, the present disclosure provides a composition comprising monopropylene glycol, monoethylene glycol, 1,2-butanediol, 2,3-pentanediol and water, wherein the composition is obtainable by a preparation process as described herein.

[0088] In a preferred embodiment, the composition is obtainable by a process which comprises contacting a carbohydrate composition with hydrogen in a reactor in the presence of water and a catalyst under conditions such that the carbohydrate composition undergoes catalytic hydrogenolysis to produce an aqueous mixture comprising monopropylene glycol, monoethylene glycol, 1,2-butanediol and 2,3-pentanediol, wherein the carbohydrate composition comprises glucose, xylose, galactose, arabinose, mannose and fructose.

[0089] Properties and Applications

[0090] The compositions of the disclosure exhibit desirable properties and may be used in various applications. In particular, the bio-based compositions described herein may be used as a low carbon footprint alternative to fossil-based glycol compositions.

[0091] The compositions of the disclosure are liquid compositions. In particular, the compositions are liquid at standard ambient temperature and pressure (1.013 bar, 25 °C).

[0092] The compositions find particular application in the manufacture of polymers. For example, polyesters are typically prepared by the condensation polymerisation of glycols with dicarboxylic acids or their derivatives, while polyurethanes are typically prepared by reacting glycols with diisocyanates. The compositions of the disclosure may therefore be used as a source of glycol monomers for the preparation of these and other polymers. The resulting polymers may have characteristic structures and properties due to the specific glycols present in the compositions.

[0093] Accordingly, one aspect of the disclosure is directed to the use of a composition of the disclosure in the manufacture of a polymer. Also provided is a method of manufacturing a polymer which involves using a composition of the disclosure as a starting material. The method may comprise contacting a composition of the disclosure with one or more other monomers under conditions such that a polymer comprising glycol monomers is formed. The polymer is preferably a polyester or a polyurethane.

[0094] Compositions of the disclosure have been found to exhibit desirable electrical conductivity, which may be advantageous from the standpoint of their use in the preparation of polymers. It is known in this regard that the mechanical properties and processability of polyesters are influenced by the electrical conductivity of the glycol monomer composition (as discussed, for example, in EP 2 679 615 Al).

[0095] Preferably, the composition has an electrical conductivity of less than 1.0 pS / cm, more preferably less than 0.5 pS / cm. The electrical conductivity can be measured using a conductivity meter such as a SevenExcellence S700 conductivity meter (Mettler Toledo). The electrical conductivity is measured at a temperature of 25 °C.

[0096] In an embodiment, the composition has a kinematic viscosity of from 20 to 40 mm2 / s. In a particular embodiment, the composition has a kinematic viscosity of from 25 to 35 mm2 / s. The kinematic viscosity is measured at a temperature of 25 °C using a U-Visc 120 viscometer from Omnitek.

[0097] In an embodiment, the composition has a density of from 1.040 to 1.100 g / cm3. In a particular embodiment, the composition has a density of from 1.045 to 1.055 g / cm3. The density is measured at a temperature of 20 °C according to ASTM D4052.

[0098] In an embodiment, the composition has a kinematic viscosity of from 20 to 40 mm2 / s and a density of from 1.040 to 1.100 g / cm3.

[0099] In an embodiment, the composition has a kinematic viscosity of from 25 to 35 mm2 / s and a density of from 1.045 to 1.055 g / cm3.

[0100] The present disclosure is further illustrated by the following examples, which are provided for illustrative purposes only. The examples are not to be construed as limiting the scope or content of the disclosure in any way. Examples

[0101] Example 1 Gas chromatography (GC) can be used to quantify the individual glycol compounds present in the compositions of the disclosure. A suitable method is described in more detail below. The water content may be determined according to ASTM E1064.

[0102] GC is performed in accordance with ASTM E2409, with relative response factors (RRF) being used to determine the amounts of the components in wt%. Measurements are conducted using a TRACE 1310 GC Basic Model (Thermo Fisher) operated with the following setup:

[0103] Using the chromatogram, the amounts of the individual components in the composition are determined in area percent (Ar.%). In order to calculate the amounts of the individual components in wt%, the corresponding RRF values are applied using the following equation:

[0104] B [corr. Ar. %] (100 - Water [Wt. %]

[0105] Share [wt%] = ■ 100 B [corr. Ar. %] 100 Retention times (RT), relative retention times (RRT; relative to monoethylene glycol) and

[0106] RRF values for selected components are given in the table below (an RRF value of 1 is used for any unknown components):

[0107] In contrast to the other glycol components listed above, extensive investigations were needed to determine the presence of 2,3-pentanediol in the compositions. GC-MS analysis revealed two unknown peaks, which database searches suggested were most likely attributable to 1-methoxy-butanol. However, this compound could be eliminated on the basis of its retention time. Since attempts to isolate the unknown component by extractive distillation were unsuccessful, batch distillation was used to produce a sample solution that contained an increased concentration of the unknown component. The sample solution was then analysed using one-dimensional and two-dimensional ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS), with the "multiple heart-cutting" technique being used for the 2D-UHPLC-MS analysis. The most probable molecular weight of the unknown component was determined to be 104.15 g / mol. This led to a variety of possible structures, including pentanediol isomers and methylbutanediol isomers. Four possible pentanediol isomer standards (1,3-pentanediol, 1,4-pentanediol, 2,4-pentanediol and 1,5-pentanediol) were eliminated on the basis of their retention times. One additional pentanediol (2,3-pentanediol) and three different methylbutanediol standards (3-methyl-

[0108] 1.3-butanediol, 2-methyl-l,3-butanediol and 2-methyl-l,4-butanediol) were then evaluated. The methylbutanediol compounds were eliminated on the basis of their retention times or because the intensities in the mass spectra differed from the sample solution. However, for

[0109] 2.3-pentanediol the retention times and mass spectra coincided with the sample solution. Spiking with the standard solution also led to an increased peak area for the sample solution. As a result of these extensive investigations it could be concluded that the unknown component is 2,3-pentanediol.

[0110] Example 2

[0111] A carbohydrate composition obtained from corn starch was subjected to a catalytic hydrogenolysis procedure as described herein. The carbohydrate composition comprised mainly (>89 wt%) glucose, as well as minor amounts of xylose, galactose, arabinose, mannose and fructose. The reaction produced an aqueous mixture comprising monopropylene glycol, monoethylene glycol, 1,2-butanediol and 2,3-pentanediol. The aqueous mixture was then subjected to a distillation procedure so as to remove some of the monoethylene glycol and water, as well as co-catalyst and heavy components. The resulting glycol composition was recovered as the distillate. A sample of the glycol composition was analysed using the methods described in Example 1.

[0112] The composition of the sample was determined to be as follows:

[0113] Example 3

[0114] The glycol composition of Example 2 was evaluated for various physical and chemical properties, as indicated below:

[0115] The glycol composition was found to exhibit a desirable combination of properties. In particular, the glycol composition exhibited desirable electrical conductivity. Example 4

[0116] A feedstock comprising hardwood chips was pretreated and then subjected to an enzymatic hydrolysis procedure as described herein to produce a carbohydrate composition. A sample of the carbohydrate composition was analysed and found to contain mainly (>89 wt%) glucose, as well as minor amounts of xylose, galactose, arabinose, mannose and fructose.

[0117] The carbohydrate composition was subjected to a catalytic hydrogenolysis procedure as described herein to produce an aqueous mixture comprising monopropylene glycol, monoethylene glycol, 1,2-butanediol and 2,3-pentanediol. The aqueous mixture was then subjected to a distillation procedure so as to remove some of the monoethylene glycol and water, as well as co-catalyst and heavy components. The resulting glycol composition was recovered as the distillate.

[0118] A sample of the glycol composition was analysed using the methods described in Example 1. The sample was found to have the following composition:

[0119] The composition and properties of the glycol composition were comparable to those of the glycol composition of Example 2. All publications, patent applications, patents and other references mentioned herein are incorporated by reference in their entirety. In addition, the materials, methods and examples given are illustrative only and not intended to be limiting. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0120] It is to be understood that while the disclosure has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the scope of the claims.

Claims

CLAIMS1. A composition comprising: monopropylene glycol; monoethylene glycol;1.2-butanediol;2.3-pentanediol; and water.

2. The composition according to claim 1, wherein the composition comprises monopropylene glycol in an amount of from 40% to 70% by weight of the composition.

3. The composition according to claim 1, wherein the composition comprises monopropylene glycol in an amount of from 50% to 60% by weight of the composition.

4. The composition according to any of the preceding claims, wherein the composition comprises monoethylene glycol in an amount of from 5% to 40% by weight of the composition.

5. The composition according to any of claims 1 to 3, wherein the composition comprises monoethylene glycol in an amount of from 5% to 25% by weight of the composition.

6. The composition according to any of the preceding claims, wherein the composition comprises 1,2-butanediol in an amount of from 5% to 25% by weight of the composition.

7. The composition according to any of claims 1 to 5, wherein the composition comprises1,2-butanediol in an amount of from 10% to 25% by weight of the composition.

8. The composition according to any of the preceding claims, wherein the composition comprises 2,3-pentanediol in an amount of from 0.1% to 5% by weight of the composition.

9. The composition according to any of claims 1 to 7, wherein the composition comprises 2,3-pentanediol in an amount of from 0.1% to 2% by weight of the composition.

10. The composition according to any of the preceding claims, wherein the composition comprises water in an amount of from 0.1% to 10% by weight of the composition.

11. The composition according to any of claims 1 to 9, wherein the composition comprises water in an amount of from 0.1% to 5% by weight of the composition.

12. The composition according to any of claims 1 to 9, wherein the composition comprises water in an amount of from 0.1% to 4% by weight of the composition.

13. The composition according to claim 1, wherein the composition comprises: monopropylene glycol in an amount of from 40% to 70% by weight of the composition; monoethylene glycol in an amount of from 5% to 40% by weight of the composition;1.2-butanediol in an amount of from 5% to 25% by weight of the composition;2.3-pentanediol in an amount of from 0.1% to 5% by weight of the composition; and water in an amount of from 0.1% to 10% by weight of the composition.

14. The composition according to claim 1, wherein the composition comprises: monopropylene glycol in an amount of from 50% to 60% by weight of the composition;monoethylene glycol in an amount of from 5% to 30% by weight of the composition;1.2-butanediol in an amount of from 10% to 25% by weight of the composition;2.3-pentanediol in an amount of from 0.1% to 2% by weight of the composition; and water in an amount of from 0.1% to 5% by weight of the composition.

15. The composition according to any of the preceding claims, wherein the composition further comprises 2,3-butanedioL16. The composition according to claim 15, wherein the composition comprises 2,3- butanediol in an amount of from 0.1% to 5% by weight of the composition.

17. The composition according to claim 15, wherein the composition comprises 2,3- butanediol in an amount of from 0.1% to 2% by weight of the composition.

18. The composition according to any of the preceding claims, wherein the composition is a bio-based composition.

19. The composition according to claim 18, wherein the composition is prepared from a wood-based raw material.

20. The composition according to any of the preceding claims, wherein the composition has an electrical conductivity of less than 1.0 pS / cm.

21. The composition according to any of the preceding claims, wherein the composition has a kinematic viscosity of from 20 to 40 mm2 / s and / or a density of from 1.040 to 1.100 g / cm3.

22. Use of a composition of any of the preceding claims in the manufacture of a polymer.