FI20245334A1 - Monopropylene glycol compositions - Google Patents

Abstract

The present disclosure provides a composition comprising monopropylene glycol and 2,3-pentanediol, wherein the monopropylene glycol is present in an amount of at least 98.0% by weight of the composition. The compositions of the disclosure have desirable properties and can be used as low carbon footprint alternatives to fossil-based glycol compositions in a variety of applications.

Description

MONOPROPYLENE GLYCOL COMPOSITIONS

FIELD

The present disclosure relates to glycol compositions and uses thereof. More particularly, the disclosure relates to compositions comprising monopropylene glycol and 2,3- pentanediol. Compositions described herein can be used as a low carbon footprint alternative to fossil-based glycol compositions in various applications.

BACKGROUND

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.

Monopropylene glycol is an important raw material that is used in a multitude of applications and industrial processes. In particular, monopropylene glycol is used to produce polymers such as polyesters and polyurethanes. Monopropylene glycol is made on an industrial scale from petrochemicals derived from crude oil, but due to environmental concerns there is a strong interest in obtaining the compound from renewable resources. In + this regard, it is known that sugars contained in plant mass can be converted to

S monopropylene glycol by catalytic hydrogenolysis. 8 25 & There remains a need for further glycol compositions. In particular, there is a need for

E monopropylene glycol compositions which exhibit desirable properties, especially as regards 3 the manufacture of polymers, and which can be prepared from renewable resources in a

O facile manner. These and other needs are met by the present disclosure.

S 30 -1-

SUMMARY

In one aspect, the present disclosure provides a composition comprising: monopropylene glycol in an amount of at least 98.0% by weight of the composition; and 2,3-pentanediol.

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.

DETAILED DESCRIPTION

Glycol Compositions

The present disclosure provides a composition comprising 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.

The composition comprises monopropylene glycol (also known as MPG, 1,2-propanediol or propane-1,2-diol) and 2,3-pentanediol (also known as pentane-2,3-diol).

The composition comprises monopropylene glycol in an amount of at least 98.0% by weight + of the composition. Preferably, the composition comprises monopropylene glycol in an

N

< amount of at least 98.1%, at least 98.2%, at least 98.3%, at least 98.4%, at least 98.5% or at 3 25 least 99.0% by weight of the composition.

LO

N

E In addition, the composition comprises 2,3-pentanediol (also known as pentane-2,3-diol). In 3 an embodiment, the composition comprises 2,3-pentanediol in an amount of from 0.1% to

O

3 2.0% by weight of the composition. Preferably, the composition comprises 2,3-pentanediol

Q 30 in an amount of from 0.1% to 1.5% by weight of the composition. -2-

In an embodiment, the composition further comprises 1,2-butanediol (also known as butane-1,2-diol). In an embodiment, the composition comprises 1,2-butanediol in an amount of from 0.1% to 0.5% by weight of the composition. In an embodiment, the composition comprises 1,2-butanediol in an amount of from 0.1% to 0.4% by weight of the composition. In a particular embodiment, the composition comprises 1,2-butanediol in an amount of from 0.1% to 0.3% by weight of the composition.

In an embodiment, the composition comprises monopropylene glycol in an amount of at least 98.0% by weight of the composition, 2,3-pentanediol in an amount of from 0.1% to 1.5% by weight of the composition, and 1,2-butanediol in an amount of from 0.1% to 0.5% by weight of the composition.

In an embodiment, the composition comprises monopropylene glycol in an amount of at least 98.1% by weight of the composition, 2,3-pentanediol in an amount of from 0.1% to 1.5% by weight of the composition, and 1,2-butanediol in an amount of from 0.1% to 0.3% by weight of the composition.

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 0.001% to 0.5% by weight of the composition. In an embodiment, the composition comprises 2,3-butanediol in an amount of from 0.001% to 0.1% by weight of the composition.

N

< In an embodiment, the composition comprises monopropylene glycol in an amount of at 3 25 least 98.0% by weight of the composition, 2,3-pentanediol in an amount of from 0.1% to & 1.5% by weight of the composition, 1,2-butanediol in an amount of from 0.1% to 0.5% by

E weight of the composition, and 2,3-butanediol in an amount of from 0.001% to 0.5% by 3 weight of the composition.

O

S

Q 30 In an embodiment, the composition comprises monopropylene glycol in an amount of at least 98.1% by weight of the composition, 2,3-pentanediol in an amount of from 0.1% to -3-

1.5% by weight of the composition, 1,2-butanediol in an amount of from 0.1% to 0.3% by weight of the composition, and 2,3-butanediol in an amount of from 0.001% to 0.1% by weight of the composition.

Preferably, the composition is substantially anhydrous, by which is meant that the composition contains less than 0.2% of water by weight of the composition. In an embodiment, the composition contains less than 0.1%, more preferably less than 0.05%, of water by weight of the composition. More preferably, the composition is anhydrous.

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 bio- based 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%. + In an embodiment, the composition is a bio-based composition wherein both the

S monopropylene glycol and the 2,3-pentanediol are bio-based compounds. In an 8 25 embodiment, the composition is a bio-based composition in which all of the carbon- & containing compounds in the composition are bio-based.

E

3 In an embodiment, the composition is a bio-based composition that is prepared from a

O wood-based raw material, such as hardwood or softwood. The wood-based raw material

O 30 may originate from, e.g., pine, poplar, beech, aspen, spruce, eucalyptus, ash, oak, maple, -4-

chestnut, willow or birch. The wood-based raw material may also be any combination or mixture of these.

Preparation Processes

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 the glycol compounds in the desired quantities.

Preferably, however, a composition of the disclosure is obtained via a process comprising catalytic hydrogenolysis of a carbohydrate composition.

More particularly, it is preferred that the composition is 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 and 2,3-pentanediol; - subjecting the aqueous mixture to a distillation procedure such that a portion of the monoethylene glycol is removed from the aqueous mixture, thereby forming a first fraction comprising monopropylene glycol and 2,3-pentanediol and a second fraction comprising purified monoethylene glycol; + - subjecting the first fraction to a distillation procedure and recovering the

S composition of the disclosure therefrom as a product. 8 25 & In order to prepare the compositions of the disclosure, it is preferred that a carbohydrate

E composition comprising a particular combination of sugars is employed. Preferably, the 3 carbohydrate composition comprises glucose, xylose and one or more sugars selected from

O galactose, arabinose, mannose and fructose. More preferably, the carbohydrate

O 30 composition comprises each of glucose, xylose, galactose, arabinose, mannose and fructose. -5-

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.

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 5% 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.

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. + As is known in the art, sugars may exist in monomeric and oligomeric forms. The term

S “monomeric” as used herein refers to a sugar molecule that is not coupled or connected to 8 25 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

E monomers coupled or connected to each other. Examples of oligomeric sugars include 3 disaccharides and trisaccharides.

O

S

Q 30 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. -6-

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.

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.

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

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.

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

S also be any combination or mixture of these. 8 25 & When a wood-based raw material is used as the carbohydrate source, the carbohydrate

E composition may be prepared by a process comprising: subjecting a wood-based feedstock 3 comprising wood chips to at least one pretreatment to form a liquid fraction and a fraction

O comprising solid cellulose particles; and subjecting the fraction comprising solid cellulose

O 30 particles to enzymatic hydrolysis to form a lignin fraction and a carbohydrate fraction. The -7-

carbohydrate fraction may be optionally purified and then used as the carbohydrate composition in the catalytic hydrogenolysis process.

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.

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.

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.

The pretreatment may comprise subjecting the wood-based feedstock to pre-steaming. In + particular, the pretreatment may comprise subjecting the wood-based feedstock received

S from the mechanical treatment to pre-steaming. The pretreatment may comprise an 8 25 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

E wood-based feedstock to pre-steaming, wherein the pre-steaming of the wood-based 3 feedstock is carried out with steam having a temperature of from 100 to 130 °C at

O atmospheric pressure. During the pre-steaming the wood-based feedstock is treated with

O 30 steam of low pressure. The pre-steaming may be also carried out with steam having a -8-

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.

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 pre- steaming with steam having a temperature of from 100 to 130 °C at atmospheric pressure.

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.

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. + The impregnation liguid may comprise water, at least one acid, at least one alkali, at least

S one alcohol, or any combination or mixture thereof. The at least one acid may be selected 8 25 from a group consisting of inorganic acids, such as sulphuric acid (H2SO4), nitric acid,

O phosphoric acid; organic acids, such as acetic acid, lactic acid, formic acid, carbonic acid; and

E any combination or mixture thereof. In one embodiment, the impregnation liguid 3 comprises sulphuric acid, e.g. dilute sulphuric acid. The concentration of the acid may be

O from 0.3% to 5.0% by weight, from 0.5% to 3.0% by weight, from 0.6% to 2.5% by weight,

S 30 from 0.7% to 1.9% by weight, or from 1.0% to 1.6% by weight. The impregnation liguid may act as a catalyst for the hydrolysis of the hemicellulose in the wood-based feedstock. In one -9-

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 Ca(OH); can be mentioned as examples to be used as the alkali in the alkaline hydrolysis.

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 wood- based 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.

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.

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 liguid. The impregnation treatment may

S be carried out as a batch process orin a continuous manner. 8 25 & The residence time of the wood-based feedstock in an impregnation reactor, i.e. the time

E during which the wood-based feedstock is in contact with the impregnation liguid, may be 3 from 5 seconds to 5 minutes, or from 0.5 to 3 minutes, or about 1 minute. The temperature

O of the impregnation liquid may be, for example, from 20 to 99 °C, or from 40 to 95 °C, or

O 30 from 60 to 90 *C. Maintaining the temperature of the impregnation liguid below 100 *C has the added utility of hindering or reducing hemicellulose from dissolving. -10-

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.

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.

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 wood- based 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.

N

& 3 25 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

E feedstock with steam having a temperature of from 130 to 240 *C under a pressure of from 3 0.17 to 3.25 MPaG followed by a sudden, explosive decompression of the wood-based

O feedstock. The wood-based feedstock may be treated with the steam for e.g. from 1 to 20

O 30 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. -11-

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.

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 same.

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 liguid. The

S output stream of the steam explosion may be mixed with a liguid to form a liguid fraction 8 25 and a fraction comprising solid cellulose particles. The liguid may be pure water or water & containing C5 sugars. The water containing C5 sugars may be recycled water from

E separation and/or washing the fraction comprising solid cellulose particles before enzymatic 3 hydrolysis. The output stream may be mixed with the liquid and the resulting mass may be 2 homogenized mechanically to break up agglomerates. & 30 -12 -

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.

The above-described pre-treatments can be performed alone or in combination. The pre- treated 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.

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 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. + In one embodiment, the enzymatic hydrolysis is carried out at a temperature of from 30 to

S 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 8 25 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

E continue for from 20 to 120 h, from 30 to 90 h, or from 40 to 80 h. 3 3 In one embodiment, the enzymatic hydrolysis may be carried out as a one-step hydrolysis

Q 30 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 -13 -

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.

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.

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.

N

< The enzymes are catalysts for the enzymatic hydrolysis. The enzymatic reaction decreases 3 25 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

E may result in cellulose being transformed into sugar monomers with enzymes. Lignin 3 present in the fraction comprising solid cellulose particles may remain essentially in solid 2 form. & 30 -14 -

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 B-glucosidase (cellobiose). The enzymes may be either commercially available cellulase mixes or manufactured on-site.

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

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.

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.

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,

S chromatography, ion exchanging, by active carbon. Purification of the carbohydrate fraction 8 25 has the added utility of providing a desired target guality of sugars. &

E While it is preferred that the carbohydrate composition is obtained from a wood-based raw 3 material, it will be appreciated that sugars obtained from other sources may also be used in 2 the catalytic hydrogenolysis process. For instance, a carbohydrate composition derived

Q 30 from corn starch may be used. -15 -

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 and 2,3-pentanediol.

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.

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.

N

& 3 25 The second catalyst may comprise at least one active component selected from tungsten & oxide, tungsten sulfide, tungsten hydroxide, tungsten bronze oxide, tungsten acid,

E tungstate, metatungstate acid, metatungstate, paratungstate acid, para-tungstate, 3 peroxotungstic acid, pertungstate, and hetero-polyacid containing tungsten. In one 3 embodiment, the second catalyst comprises or consists of homogenous sodium tungstate.

S 30 -16-

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

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.

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.

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. + The catalytic conversion results in hydrogenolysis of the carbohydrate composition such

S that an agueous mixture comprising monopropylene glycol, monoethylene glycol and 2,3- 8 25 pentanediol is formed. The agueous mixture may comprise other glycols besides, such as

O 1,2-butanediol and 2,3-butanediol. fz 3 The aqueous mixture is then subjected to a distillation procedure such that a portion of the 2 monoethylene glycol is removed from the aqueous mixture, thereby forming a first fraction

Q 30 comprising monopropylene glycol and 2,3-pentanediol and a second fraction comprising purified monoethylene glycol. -17 -

The distillation of the aqueous mixture 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 a fraction comprising monopropylene glycol and 2,3-pentanediol may be recovered as a top stream from the distillation column.

The distillation of the aqueous mixture 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.

The composition of the disclosure may then be recovered from the first fraction by subjecting the first fraction to a distillation procedure.

Preferably, the composition of the disclosure is recovered from the first fraction by a distillation procedure comprising: - providing the first fraction as a mixture feed into a first distillation column comprising from 20 to 200 theoretical stages, in which first distillation column a first distillation process is carried out; + - providing a distillation solvent into the first distillation column, wherein the

S distillation solvent is a diol or a sugar alcohol having a boiling point that is at least 80 8 25 °C higher than the boiling point of monopropylene glycol at atmospheric pressure, & and wherein the weight ratio of the distillation solvent to the total mixture feed is

E from 2.5:1 to 10:1; 3 - purifying the mixture feed with the aid of the distillation solvent by carrying out the

O first distillation process at a top temperature of from 70 to 140 °C, and a top

O 30 pressure of from 0.01 to 0.2 bar, and with a reflux ratio of from 2 to 50; and - recovering the composition of the disclosure. -18 -

Distillation may generally be considered a process of separating components or substances from a mixture by using selective boiling and condensation. Distillation may result in essentially complete separation into nearly pure components, or it may be a partial separation that increases the concentration of selected components in the mixture. The distillation process exploits differences in the relative volatility of the different components in the mixture.

A “theoretical stage”, a “theoretical plate” or a “distillation stage” as it may also be called can be considered as a hypothetical zone or stage in which two phases, such as the liquid and vapor phases of a substance, establish an equilibrium with each other. Such equilibrium stages may also be referred to as an equilibrium stage, ideal stage, or a theoretical tray.

The performance of many separation processes depends on having series of equilibrium stages and may be enhanced by providing more such stages. In other words, having more theoretical plates increases the efficiency of the separation process be it either a distillation, absorption, chromatographic, adsorption or similar process.

When designing the distillation of a certain media, the number of theoretical stages is usually first designed or considered and the theoretical stages then define the physical height of the distillation column. In the distillation column the theoretical stages or distillation stages may be formed by trays or packings, also called packed beds. A packed + bed may be a structured packed bed or a random packed bed.

N

& 3 25 The combination of the specified number of theoretical stages and the specified reflux ratio & together with the distillation solvent in the specified amount enabled efficient separation of

E the mono-propylene from the mixture feed. 3 0 The first fraction (hereinafter referred to as the “mixture feed”) may be fed into the first

O 30 distillation column in the form of a liguid or as a steam or vapor, or as any mixture thereof. -19-

Prior to the distillation process there may be one or more separation or purification processes taking place. For example, water, alcohols such as methanol and ethanol, organic acids, sugar alcohols such as glycerol, catalysts and residual sugars may be removed in separate steps in a desired order. Typically water and alcohols having the lowest boiling point may be removed first, followed by removing components having a boiling point higher than monoethylene glycol. The remaining components may comprise mainly diols with boiling points close to the one of monopropylene glycol which may then be separated in further purification steps.

The first distillation process is carried out in a first distillation column, wherein a distillation solvent is fed to assist or aid in the separation of the desired components from the mixture feed.

The distillation solvent is a diol or a sugar alcohol having a boiling point that is at least 80 °C higher than the boiling point of monopropylene glycol at atmospheric pressure. The distillation solvent may have a boiling point that is at least 85 °C, or at least 90 °C, higher than the boiling point of monopropylene glycol at atmospheric pressure. The distillation solvent may have a boiling point that is from 80 to 100 °C, from 82 to 98 °C, or from 85 to 95 °C, higher than the boiling point of monopropylene glycol at atmospheric pressure. The distillation solvent may have a boiling point of from 265 to 350 °C, from 265 to 300 °C, or from 275 to 300 °C. In one embodiment, the distillation solvent is a diol having a boiling point that is at least 80 °C higher than the boiling point of monopropylene glycol at < atmospheric pressure.

S

8 25 In one embodiment, the distillation solvent is a sugar alcohol having a boiling point that is at & least 80 °C higher than the boiling point of monopropylene glycol at atmospheric pressure.

E

3 In one embodiment, the weight ratio of the distillation solvent to the total mixture feed is

O from 5:1 to 8:1. The specified amount of distillation solvent used in the distillation process

O 30 efficiently assists in the separation. -20-

In one embodiment, the distillation solvent is triethylene glycol or tripropylene glycol. In one embodiment, the distillation solvent is triethylene glycol.

The distillation solvent used has the added utility of having a boiling point higher than monopropylene glycol and also other diols in mixture feed. Thus, the distillation solvent used may not boil in the first distillation column and the vapor flow in the first distillation column may not increase even though a high amount of the distillation solvent is used.

Thus, also the column size does not need to be increased in large extent due to the amount of the distillation solvent used.

The first distillation column may comprise from 20 to 200, or from 40 to 120, or from 40 to 80, or from 60 to 120, theoretical stages. The number of theoretical stages being from 20 to 200 has the added utility of enabling separation to take place in rather high efficiency so that reasonable reflux ratios may be used.

The mixture feed may be fed into the first distillation column at a point which is below the point at which the distillation solvent is fed into the first distillation column.

The mixture feed may be fed into the first distillation column at a point which is situated between two theoretical stages. The distillation column may comprise packings or packed beds, wherein one packed bed comprises two or more theoretical stages. In such a situation, the mixture feed may be fed into the distillation column at a point between two + such packed beds.

N

& 3 25 The mixture feed may be fed into the first distillation column at a point which is situated & below, above, or on at least one theoretical stage. When using plates as the theoretical

E stages the mixture feed may be fed on a theoretical stage or above a theoretical stage. 3 0 In one embodiment, the distillation solvent is fed into the first distillation column at any

O 30 point between 1st and 10th, or 2nd and 9th, or 3rd and 7th, theoretical stages as calculated from the top of the first distillation column. The distillation solvent may be fed into the first -21-

distillation column above the topmost theoretical stage as calculated from the top of the first distillation column.

In one embodiment, the first distillation process is carried out with a reflux ratio of from 3 to 40, or from 4 to 30, or from 5 to 20, from 6 to 10. The reflux ratio may generally be defined as the ratio of the top liquid returned to the distillation column divided by the liquid removed or recovered from the distillation column as product.

In one embodiment, the first distillation process is carried out at a top temperature of from 75 to 135 °C, or from 90 to 130 °C, or from 100 to 120 °C.

In one embodiment, the first distillation process is carried out at a bottom temperature of from 150 to 230 °C, or from 160 to 200 °C, or from 170 to 190 °C.

In one embodiment, the first distillation process is carried out at a top pressure of from 0.01 to 0.2 bar, or from 0.015 to 0.1 bar, or from 0.02 to 0.1 bar.

In one embodiment, the pressure drop over the distillation column is from 0.05 to 0.2 bar, or from 0.07 to 0.15 bar, or from 0.08 to 0.1 bar.

In one embodiment, the residence time of the mixture feed and the distillation solvent in the first distillation column is from 1 to 10 minutes, or from 1.2 to 7 minutes, or from 1.5 to + 6 minutes, or from 1.8 to 5.4 minutes.

S

8 25 The bottom temperature of the first distillation column may be kept at a temperature of at & most 230 °C. Maintaining the bottom temperature of the distillation column at a

E temperature of at most 230 *C has the added utility of hindering or reducing compound 3 degradation to take place.

O

S

Q 30 The term ”top temperature” as used herein refers to the temperature at the vapor space in the distillation column that is above the topmost packed bed or stage and below the vapor -22-

pipe of the distillation column. It is clear to the person skilled in the art that the temperature in the distillation column as such may differ from the temperature in e.g. the condenser or the reboiler that may be operationally connected to the distillation column.

The term “bottom temperature” as used herein refers to the temperature of the liquid in the column sump.

The term “top pressure” as used herein refers to the pressure at the vapor space in the distillation column that is above the topmost packed bed or stage and below the vapor pipe of the distillation column.

In one embodiment, at least one condenser is used in the distillation process. In one embodiment, the distillation arrangement comprises at least one condenser. The condenser(s) used may be selected from partial condensers, total condensers and combinations thereof. The condenser(s) may be heat integrated or they may use a cooling medium, such as cooling water, or they may function with air cooling.

In one embodiment, a reboiler is used in the distillation process. In one embodiment, the distillation arrangement comprises a reboiler. The reboiler may be operated at a vapor pressure of from 0.06 to 0.4 bar, or from 0.1 to 0.2 bar.

In one embodiment, the process comprises: + - removing impurities together with the distillation solvent in a bottom stream from

S the first distillation column; and 8 25 - removing monopropylene glycol and 2,3-pentanediol in a top stream from the first & distillation column. j 3 In one embodiment, the process comprises recycling the distillation solvent removed in the

O bottom stream from the first distillation process back into the first distillation column. From

O 30 the first distillation column the distillation solvent may be led into a recovery column. In the recovery column lighter components may be removed in a top stream from the recovery -23-

column and the distillation solvent may be removed in a bottom stream from the recovery column. The bottom stream comprising mainly the distillation solvent may then be led back into the first distillation column and thus reused. If needed, a part of the recycled flow of distillation solvent may be continuously purged in order to reduce or limit the accumulation of heavier degradation compounds if these appear.

In an embodiment, the process comprises providing the monopropylene glycol and 2,3- pentanediol removed in a top stream from the first distillation process into a second distillation column, wherein a second distillation process is carried out.

Preferably, the process comprises providing the monopropylene glycol and 2,3-pentanediol removed in a top stream from the first distillation process into a second distillation column, wherein a second distillation process is carried out to recover the composition of the disclosure.

In one embodiment, the second distillation process is carried out at a top temperature of from 104 to 140 °C, or from 90 to 130 °C, or from 100 to 120 °C.

In one embodiment, the second distillation process is carried out at a bottom temperature of from 134 to 170 °C, or from 145 to 165 °C, or from 150 to 160 °C.

In one embodiment, the second distillation process is carried out at a top pressure of from s 0.1 to 0.5 bar. & 3 25 In one embodiment, the second distillation process is carried out at a bottom pressure of & from 0.15 to 0.6 bar. j 3 As a result of the second distillation process, the composition of the disclosure may be

O recovered as a bottom stream or as a side-draw in the stripping section. A top stream

O 30 comprising 2,3-butanediol together with water and a mixture of light components may also recovered. - 24 -

In a further aspect, the present disclosure provides a composition comprising monopropylene glycol in an amount of at least 98.0% by weight of the composition, and 2,3- pentanediol; wherein the composition is obtainable by a preparation process described herein.

Properties and Applications

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 monopropylene glycol compositions.

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).

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.

N

< Accordingly, one aspect of the disclosure is directed to the use of a composition of the 3 25 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

E method may comprise contacting a composition of the disclosure with one or more other 3 monomers under conditions such that a polymer comprising glycol monomers is formed. 2 The polymer is preferably a polyester or a polyurethane. & 30 -25-

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).

Preferably, the composition has an electrical conductivity of less than 0.01 puS/cm, more preferably less than 0.002 puS/cm, even more preferably less than 0.001 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.

The compositions may also be used in other applications. For example, the compositions may be used in coolant and heat transfer fluids, de-icing agents, food products, pharmaceutical compositions, cosmetic compositions and detergent compositions. The low electrical conductivity of the compositions renders them especially useful in fluids for cooling systems, such as those used in data centers, electronics, and industrial machinery, for which it is important to minimise the risk of electrical damage to sensitive components and circuits.

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.

N

& 3 25 Examples &

E Example 1 3 0 Gas chromatography (GC) can be used to guantify the individual glycol compounds present

O 30 in the compositions disclosed herein. A suitable method is described in more detail below.

The water content may be determined according to ASTM E1064. -26-

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:

Carrier gas H2 with a flow rate of 1.0 mL/min (33.6 cm/s, 54.0 kPa at

TTT

Temperature ramping Oven temperature starts at 100 °C with a holding time of 2 min, following by an increase of temperature to 200 °C with a heating rate of 10 K/min and a holding time of 12 min

Gas flows Hydrogen: 35 ml/min

Nitrogen: 40 mL/min

Air: 350 mL/min

Washing cycles Cycles are performed with methanol using the following settings: s Pre-injection: 3 cycles with a solvent volume of 8.0 pL

N Rinse: 6 rinses with a rinse volume of 6.0 pL

S Post-injection: 6 cycles with a solvent volume of 8.0 mL &

Tr a Using the chromatogram, the amounts of the individual components in the composition are 3 determined in area percent (Ar.%). In order to calculate the amounts of the individual 3 components in wt%, the corresponding RRF values are applied using the following equation: & 10 -27 -

Share [wt%] = B [corr. Ar. Yo] | (100 — Water [Wt. %] . 100

YB [corr.Ar.%] 100

B [corr.Ar.%| = Sharecompouna AT-%

RRF compound

Retention times (RT), relative retention times (RRT; relative to monopropylene glycol) and

RRF values for selected components are given in the table below (an RRF value of 1 is used for any unknown components): oon | mmm | wri [wwe amen | sa | om | 1 snes — | s | oe | m

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

N attributable to 1-methoxy-butanol. However, this compound could be eliminated on the

N basis of its retention time. Since attempts to isolate the unknown component by extractive 3 15 distillation were unsuccessful, batch distillation was used to produce a sample solution that

N contained an increased concentration of the unknown component. The sample solution : was then analysed using one-dimensional and two-dimensional ultra-high performance 3 liquid chromatography-mass spectrometry (UHPLC-MS), with the “multiple heart-cutting” 3 technique being used for the 2D-UHPLC-MS analysis. The most probable molecular weight

N 20 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 -28 -

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- 1,3-butanediol, 2-methyl-1,3-butanediol and 2-methyl-1,4-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 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.

Example 2

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 glycol 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 mixture was recovered as the distillate. + A sample of the glycol mixture was analysed using the methods described in Example 1. The

N

< composition of the sample was determined to be as follows: 3 25

LO

N

I a a <t

O

O

LO

+

N

O

N

- 29-

Monopropylene glycol 54.81

Monoethylene glycol 23.52 1,2-Butanediol 15.76 2,3-Pentanediol

Example 3

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.

The carbohydrate composition was subjected to a catalytic hydrogenolysis procedure as described herein to produce an agueous mixture comprising monopropylene glycol, monoethylene glycol, 1,2-butanediol and 2,3-pentanediol. The agueous glycol 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 mixture was s recovered as the distillate. & 15

O

> A sample of the glycol mixture was analysed using the methods described in Example 1. The

LO

N sample was found to have the following composition: = a <t

O

O

LO

+

N

O

N

- 30 -

Ta [om

Example 4

A glycol mixture was prepared as described in Example 2 and then subjected to a distillation procedure to produce a glycol composition of the disclosure.

The distillation process was performed in two steps. The first step was an extractive distillation step in which mainly monoethylene glycol and other heavy boiling components were removed in the bottom product. The extracting agent used in the first step contained 99.4 wt% triethylene glycol (TEG), 0.5 wt% diethylene glycol and 0.1 wt% water. In the second step, the distillate of the first step was further processed and the low boiling components were removed as the distillate. The final product was separated as a side draw. s The experiments were performed on a distillation column with an inner diameter of 250

N 15 mm and with structured packing as internals for both steps. For the first distillation step, 3 the column was equipped with 3.86 m of structured packing below the feed position. In addition, the column was equipped with 3.54 m of structured packing between the feed

ZE position and the TEG feed position. An additional 0.96 m structured packing was used 3 above the TEG feed position. For the second distillation step, the column was equipped 3 20 with 3.54 m structured packing below the feed position and 2.57 m of structuring packing above the feed position. The liquid side draw was 1.12 m above the bottom vessel.

CYPlus™ structured packing was used in all cases. -31-

The first distillation step was conducted under the following conditions:

Top pressure (mbar(a)) 60

Mixture feed flow rate (kg/h)

TEG flow rate (kg/h)

Distillate flow (kg/h) 69

Distillate to feed ratio

Bottom temperature (°C) 150-160

Monoethylene glycol was removed in the bottom product and in all distillate samples the monoethylene glycol concentration was < 1 wt.-%.

The second distillation step was conducted under the following conditions:

Top pressure (mbar(a))

Feed flow rate (kg/h) 69 0

Side-draw flow rate (kg/h) a Distillate flow rate (kg/h)

O

N Side-draw to feed ratio

O

TP 10 & _ A sample of the resulting product was analysed using the methods described in Example 1. a a The sample was found to have the following composition: >

O

LO

+

N

O

N

-32-

Monopropylene glycol 98.40

Example 5

The product of Example 4 and a fossil-based monopropylene glycol composition (299.5%

MPG; obtained from Carl Roth GmbH & Co. KG) were evaluated for various physical and chemical properties. A comparison of their properties is presented in the following table:

Product of

Property Test Method Fossil-based MPG

Example 4

ASTM E2680 Colourless, clear | Colourless, clear

Specific gravity at 20°C ASTM D4052 1.0374 1.0380

Acidity as acetic acid [wt%] | ASTM 1613 0.001 0.001 i

N Ash [wt%] ASTM D482 <0.001 <0.001

N

0 Conductivity <0.001 0.005

O Conductivity [uS/cm]

LO meter; 25 °C

N

I

= + The product of Example 4 exhibited a desirable combination of properties. In particular, the

O

= 10 product exhibited desirable electrical conductivity as compared with the fossil-based +

N composition.

N

-33-

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.

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. i

N

O

N

O

<Q

LO

N

I a a <t

O

O

LO

+

N

O

N

- 34 -

Claims (14)

1. A composition comprising: - monopropylene glycol in an amount of at least 98.0% by weight of the composition; and - 2,3-pentanediol.

2. The composition according to claim 1, wherein the composition comprises monopropylene glycol in an amount of at least 98.1%, at least 98.2%, at least 98.3%, at least 98.4% or at least 98.5% by weight of the composition.

3. The composition according to claim 1 or claim 2, wherein the composition comprises 2,3-pentanediol in an amount of from 0.1% to 2.0% by weight of the composition.

4. The composition according to claim 3, wherein the composition comprises 2,3- pentanediol in an amount of from 0.1% to 1.5% by weight of the composition.

5. The composition according to any of the preceding claims, wherein the composition further comprises 1,2-butanediol.

6. The composition according to claim 5, wherein the composition comprises 1,2- butanediol in an amount of from 0.1% to 0.5% by weight of the composition. N

< 7. The composition according to claim 1, wherein the composition comprises: 3 25 - monopropylene glycol in an amount of at least 98.0% by weight of the & composition; E - —2,3-pentanediol in an amount of from 0.1% to 1.5% by weight of the 5 composition; and 0 - 1,2-butanediol in an amount of from 0.1% to 0.5% by weight of the N Q 30 composition. -35-

8. The composition according to any of the preceding claims, wherein the composition further comprises 2,3-butanediol.

9. The composition according to claim 8, wherein the composition comprises 2,3- butanediol in an amount of from 0.001% to 0.5% by weight of the composition.

10. The composition according to any of the preceding claims, wherein the composition contains less than 0.2% of water by weight of the composition.

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

12. The composition according to claim 11, wherein the composition is prepared from a wood-based raw material.

13. The composition according to any of the preceding claims, wherein the composition has an electroconductivity of less than 0.002 uS/cm.

14. Use of a composition according to any of the preceding claims in the manufacture of a polymer. i N O N O <Q LO N I a a <t O O LO + N O N -36-