WO2016058621A1

WO2016058621A1 - Bio-based composition

Info

Publication number: WO2016058621A1
Application number: PCT/EP2014/002784
Authority: WO
Inventors: Pietro Palmisano; Rocco Roberto TANGORRA; Dario Livio
Original assignee: Biochemtex S.P.A.
Priority date: 2014-10-16
Filing date: 2014-10-16
Publication date: 2016-04-21

Abstract

It is disclosed a bio-based composition derived from a lignin of a ligno-cellulosic biomass comprising at least 50% by weight of aromatic compounds, which can be monomeric aromatic compounds and non-monomeric aromatic compounds. The monomeric compounds have a molecular weight which is less than 210gr/mole. The bio-based composition has an acidity which is less than 80 mg KOH/g, and it is stable over time. Namely, the amount of monomeric aromatic compounds does not decrease by more than 2% of the aromatic compounds by weight after storing the composition for a time between 1 week and 1 year in sealed conditions.

Description

Title: BIO-BASED COMPOSITION

DESCRIPTION

BACKGROUND

Ligno-cellulosic biomass, which comprises insoluble carbohydrates and lignin, may be converted to many bio-fuels and other biochemicals.

In a biorefinery model, typically the carbohydrates of the ligno-cellulosic biomass are first converted for instance to ethanol, the process producing a solid residue which is rich in lignin.

The solid residue may be burn to supply heat and energy to the biorefinery, or it may be further converted to other biochemicals, which are derived from the lignin of the residue.

The biochemicals, or intermediates to produce biochemicals, may comprise aromatic compounds derived from the lignin, which is a polymeric compounds comprising basic aromatic structures.

In some cases, biochemicals are produced from the conversion of the lignin of the ligno-cellulosic biomass, without any preceding conversion step of the carbohydrates.

It is also known in the art that the ligno-cellulosic biomass may be first subjected to a pre-treatment in order to reduce its recalcitrance to the action of catalysts, in particular of biocatalyst such as enzymes.

Some of these pre-treatments involve the use of strong inorganic acids, such as sulfuric acid, which may leave some functional groups and derivatives bounded to the lignin. These residual inorganic compounds may further evolve to acidic compounds in the conversion of the lignin.

One way to convert the lignin of the ligno-cellulosic biomass comprises a pyrolysis of the biomass, in absence or depletion of oxygen. The bio-oils which are produced contain large amount of oxygen, and carboxylic compounds. In general, they have very acidic properties and are instable over short time periods. One way used to correct the acidity is the addition of a base or other neutralization agent, but this increases the cost of the bio-oil, which is a low added value product.

Another way to convert the lignin of the ligno-cellulosic biomass comprises reacting the lignin with a catalyst in the presence of Hydrogen.

1

CONHRBfiATTOW COPY WO2013124456A2, WO2013142006A2, WO2013124457A2, WO2013124458A2, WO2013124459A2,, WO2013124461A2 disclose an operational continuous process to convert lignin as found in ligno- cellulosic biomass before or after converting at least some of the carbohydrates. The continuous process has been demonstrated to create a slurry comprised of lignin, raise the slurry comprised of lignin to ultra-high pressure, deoxygenate the lignin in a lignin conversion reactor over a catalyst which is not a fixed bed without producing char. The conversion products of the carbohydrates or lignin can be further processed into polyester intermediates for use in polyester preforms and bottles.

WO2011117705A2 discloses a process for the conversion of lignin to liquid hydro- carbons comprising: subjecting the lignin to hydrogenolysis in the presence of at least one hydrogenolysis catalyst, at a temperature ranging from 250 DEG C to 350 DEG C, preferably ranging from 290 DEG C to 320 DEG C, so as to obtain depolymerized lignin; subjecting said depolymerized lignin to hydrotreating so as to obtain a mixture of liquid hydrocarbons. Said liquid hydrocarbons can be used as such (biofuels) for the production of reformulated gasolines, or they can be used for the production of gasolines or of gas oils through conventional refining processes.

SUMMARY

It is disclosed a bio-based composition derived from a lignin of a ligno-cellulosic biomass comprising at least 50% by weight of aromatic compounds, which can be monomeric aromatic compounds and non-monomeric aromatic compounds, wherein the monomeric compounds have a molecular weight which is less than 210 gr/mole. The bio-based composition has an acidity which is less than 80 mg KOH/g, and it is stable over time. Namely, the amount of monomeric aromatic compounds does not decrease by more than 2% of the aromatic compounds by weight after storing the composition for a time between 1 week and 1 year in sealed conditions.

It is also disclosed that the total amount of monomeric aromatic compounds may be in a range between 10% and 40% of the aromatic compounds by weight.

It is further disclosed that the monomeric aromatic compounds comprise monomeric phenolic compounds, and the total area of the monomeric phenolic compounds under a GC/MS curve of the bio-based composition may be within the range between 40% and 90% of the total area under the GC/MS curve. It is also disclosed that the aromatic compounds may comprise non-oxygenated aromatic compounds selected from the group consisting of benzene, toluene and xylene, or a mixture thereof.

It is further disclosed that the total amount of non-oxygenated aromatic compounds may be less than 5% of the composition by weight.

It is also disclosed that the total amount of the aromatic compounds may be at least a value selected from the group consisting of 60%, 70%, 80% and 90% of the composition by weight.

It is further disclosed that the total amount of monomeric aromatic compounds may be a value in a range selected from the group consisting of between 15% and 35%, and between 20% and 30% of the aromatic compounds by weight.

It is also disclosed that the total area of the monomeric phenolic compounds under a GC/MS curve of the bio- based composition may be a value in a range selected from the group consisting of between 40% and 80%, between 45% and 75% , and between 50% and 70% of the total area under the GC/MS curve.

It is further disclosed that the composition may have an acidity which is less than a value selected from the group consisting of 70, 50, 30 and 20 mg KOH/g of the composition.

It is also disclosed that the percent amount of total carboxylic acids may be less than a value selected from the group consisting of 1%, 0.5%, 0.3%, and 0.1% by weight of the composition.

It is further disclosed that the percent amount of total inorganic compounds may be less than a value selected from the group consisting of lOOOppm, 5000ppm, 3000ppm, 2000ppm, and lOOOppm by weight of the composition.

It is also disclosed that the amount of monomeric aromatic compounds may not decrease by more than a value selected from the group consisting of 1.5%, 1.0%, and 0.5% of the aromatic compounds by weight after storing the composition for a time between 1 week and 1 year in sealed conditions.

It is further disclosed that the amount of monomeric aromatic compounds may not decrease by more than 2% of the aromatic compounds by weight after storing the composition for a time selected from the group consisting of 2 months, 4 months, 6months and 1 year at 25°C in sealed conditions.

It is also disclosed a continuous process for converting a lignin of a ligno-cellulosic biomass to the disclosed bio- based composition, comprising the steps of: a. introducing a slurry comprised of lignin into a lignin conversion reactor

b. Converting at least a portion of the lignin of the pre-treated ligno-cellulosic biomass feedstock into first lignin conversion products by contacting the lignin with hydrogen in the presence of a first catalyst at a lignin conversion temperature,

c. Removing the first lignin conversion products from the lignin conversion reactor, wherein the lignin conversion products comprise the disclosed bio-based composition.

It is further disclosed that the lignin may be converted at a lignin conversion temperature in the range selected from the group consisting of 190°C to 370°C, 210°C to 370°C, 220°C to 360°C, 240°C to 360°C, 250°C to 360°C, 280°C to 360°C, 290°C to 350°C, and 300°C to 330°C.

It is also disclosed that the lignin may be converted at a lignin conversion pressure selected from the group consisting of 70 bar to 300 bar, 80 bar to 245 bar, 82 bar to 242 bar, 82 bar to 210 bar, 90 bar to 207 bar and 90 bar to 172 bar.

It is further disclosed that at least a portion of the hydrogen may be derived from a hydrogen donor.

It is also disclosed that the first catalyst may comprise a sponge elemental metal catalyst.

It is further disclosed that the sponge elemental catalyst may comprise a metal selected from the group consisting of palladium, platinum, nickel, ruthenium, rhodium, molybdenum, cobalt, and iron.

It is also disclosed that at least a portion of the composition may be further catalytically converted to second lignin conversion products after being stored for a time greater than 1 day and less than 2 years, wherein the percent amount by weight of total aromatic compounds comprised of benzene, toluene and xylene in the second lignin conversion products is greater than in the first lignin conversion products.

DETAILED DESCRIPTION

It is disclosed a bio-based composition which comprises a majority of aromatic compounds, which is a stable composition, meaning that the composition does not change over a long period of time. Thereby, the composition may be stored for a long time, before being used or being further converted to bio-chemicals.

By the term "bio-based" it is meant a product derived from or synthesized by a renewable biological feedstock, such as, for example, an agricultural, wood industry, pulp and paper industry, forestry, plant, bacterial, or animal feedstock. In this context the composition may be exclusively derived from a renewable biological feedstock.

A bio-based product differs from the corresponding petrochemical-derived product by the isotopic abundance of contained Carbon. It is known in art that there are three Carbon isotopes (namely 12C, 13C and 14C), and that isotopic ratios of the isotopes of carbon, such as the 13C/12C carbon isotopic ratio or the 14C/12C carbon isotopic ratio, are different in petrochemical derived products and bio- based products due to different chemical processes and isotopic fractionation. In addition, radioactive decay of the unstable 14C carbon radioisotope leads to different isotope ratios in bio-based products compared to petrochemical derived products. Measurements of isotopic abundance may be performed, for example, by liquid scintillation counting, accelerator mass spectrometry, or high precision isotope ratio mass spectrometry.

Bio-based content of a product may be verified by ASTM International Radioisotope Standard Method D6866. ASTM International Radioisotope Standard Method D6866 determines bio-based content of a material based on the amount of bio-based carbon in the material or product as a percent of the weight (mass) of the total organic carbon in the material or product. Bio-based products will have a carbon isotope ratio characteristic of a biologically derived composition.

The bio-based composition is derived from a ligno-cellulosic biomass, which comprises carbohydrates and a lignin; the ligno-cellulosic biomass has been preferably pre-treated to remove at least a portion of the carbohydrates. More specifically, the disclosed bio-based composition is derived from the lignin of the ligno-cellulosic biomass. The bio-base composition comprises a majority of aromatic compounds, which in the present disclosure are hydrocarbon aromatic compounds. The aromatic compounds can be monomeric and oligomeric compounds. In the present disclosure, by monomeric compounds it is meant any compounds having a molecular weight which is less than or equal to 210gr/mole, which is the molecular weight of the syringyl unit of the lignin. The syringyl unit is often considered in the art as the reference monomeric unit of the lignin, which has a polymeric structure. Thereby, oligomeric compounds are all the compounds having a molecular weight greater than 210 gr/mole, being dimeric compounds all the compounds having a molecular weight between 211gr/mole and 410gr/mole, and heavy compounds all the compounds having a molecular weight which is greater than 410gr/mole.

Aromatic compounds comprises all the compounds having at least one aromatic ring. Thereby, the aromatic compounds may have also two aromatic rings or more aromatic rings. Aromatic ring is a basic and not ambiguous concept in the organic chemistry and it is thereby not described. According to present definition of aromatic compounds, aromatic compounds comprise compounds having one or more functional groups chemically bounded to the aromatic ring. Said functional groups may be selected from the group of hydroxyl-, methoxy- and alkylic- groups.

Aromatic compounds comprise phenolic compounds, which are compounds consisting of a hydroxyl group (-OH) bonded directly to an aromatic hydrocarbon group. The simplest of the class is phenol, which is also called carbolic acid. Phenolic compounds are classified as simple phenols or polyphenols based on the number of phenol units in the molecule.

Aromatic compounds may be oxygenated compounds and non-oxygenated compounds. Oxygenated compounds are compounds which contain at least one Oxygen in the chemical structure. Non- oxygenated compounds are compounds which do not contain Oxygen in the chemical structure

Phenols are therefore oxygenated compounds.

Benzene, toluene and xylene are not-oxygenated compounds. The bio-base composition comprises a majority of aromatic compounds, that is the total amount of the aromatic compounds is at least 50%, more preferably at least 60%, even more preferably at least 70%, even yet more preferably at least 80%, and most preferably at least 90% of the composition by weight.

A relevant portion of the aromatic compounds in the disclosed bio-based composition are comprised of monomeric aromatic compounds. Namely, the total amount of monomeric aromatic compounds is preferably in a range between 10% and 40%, more preferably between 15% and 35%, and most preferably between 20% and 30% of the aromatic compounds by weight.

A relevant portion of the monomeric aromatic compounds are comprised of phenolic compounds, which are thereby monomeric phenolic compounds. The amount of monomeric phenolic compounds may be determined by means of gas chromatography (GC/MS) measurements according to the analytical protocol reported in the experimental section. The composition is determined in terms of the area under the GC/MS measurement curve. Namely, the total area of the monomeric phenolic compounds under the GC/MS curve of the bio-based composition may be within the range between 40% and 90%, more preferably between 40% and 80%, even more preferably between 45% and 75% , and most preferably between 50% and 70% of the total area under the GC/MS curve.

The disclosed bio-based composition may further comprise limited amount of non-oxygenated aromatic compounds. Namely, the total percent amount of non-oxygenated aromatic compounds may be less that 5% of the composition by weight.

Non-oxygenated aromatic compounds may comprise benzene, toluene and xylene, and mixture thereof.

The disclosed bio-based composition is further characterized by having a very low acidity. The acidity of the composition is defined as the amount of KOH base used to neutralize 1 gr of the composition, according to the standard method BS EN 14104. The disclosed bio-based composition has an acidity which is less than 80mg KOH/ gr , preferably less than 70mg KOH/ gr, more preferably less than 50mg KOH/ gr, even more preferably less than 30mg KOH/ gr and most preferably less than 20mg KOH/ gr.

The disclosed bio-based composition may comprise very limited amounts of carboxylic acids.

Carboxylic acids comprises for instance acetic acid, propionic acid and butanoic acid.

Carboxylic acids may be formed in the conversion of the carbohydrates of the ligno-cellulosic biomass. Namely, even if the ligno-cellulosic biomass has been pretreated to remove at least a portion of the carbohydrates, some of them may still be present and converted to carboxylic acids. As detailed in the following of the present specification, the bio-based composition is derived from the lignin of the ligno-cellulosic biomass by means of a conversion process which promotes the conversion of the carbohydrates to gaseous products such as Hydrogen carbon dioxide and methane.

The percent amount of total carboxylic acids is preferably less than 1%, preferably less than 0.5%, more preferably less than 0.3%, most preferably less than 0.1% by weight of the composition.

The disclosed bio-based composition is also preferably void of inorganic acids, such as sulfuric acid and chloride-based acids, as the whole process for producing the composition from the ligno- cellulosic biomass, is conducted without the use of inorganic acids, such as sulfuric acid.

The disclosed bio-based composition may be further characterized by having a very low amount of inorganic compounds. Inorganic compounds would be present in the case that an inorganic base would be used to reduce the acidity of the composition, in the case that the composition would contain some amounts of organic and/or inorganic acids derived from the process used to produce the composition. Inorganic compounds may include thereby inorganic salts, in associated or disassociated form.

The percent amount of total inorganic compounds is preferably less than lOOOpart per million (ppm), preferably less than 5000ppm, more preferably less than 3000ppm, more preferably less than

2000ppm, and most preferably less than lOOOppm by weight of the composition. It is known in the industry bio-based monomeric compositions as stable over time as the monomers will react with each other and reform into the oligomers of lignin. Surprisingly, the disclosed bio- based composition is further characterized by having a prolonged time stability. Namely, inventors have performed different analyses at different times and noted that it was not subjected to appreciable modifications. The bio-based composition was stocked in sealed oil drums under an atmosphere of air and stored at 25°C. The analyses were aimed to study the ageing effects on the re- polymerization of the monomeric fraction of the composition, as this property affects the possibility to use the bio-based composition over time. Therefore, the amount of monomeric aromatic compounds in the composition does not decrease by more than 2%, preferably by more than 1.5%, more preferably by more than 1.0%, and most preferably by more than 0.5% of the aromatic compounds by weight after storing the composition for a time between 1 week and 1 year in sealed conditions stability. The time frame may be also 2 months, or 4 months, or 6 months or 1 year. The bio-based composition is preferably stored sealed in air, or inert atmosphere, and at 25°C, or less, even if it is believed that seasonal temperature changes should not affect stability.

The bio-based composition may be produced according to the teaching of WO2013124456A2, WO2013142006A2, WO2013124457A2, WO2013124458A2, WO2013124459A2, and

WO2013124461A2, which are incorporated herein for reference.

Once produced, the bio-based composition may be stored over a long time period, which may be up to 1 year or more, preferably up to two years, before being converted to a number of different chemical biofuels and intermediates, which preferably are characterized by a total percent amount of benzene, toluene and xylene (BTX) by weight than the total percent amount of BTX in the claimed composition.

The conversion of phenols to BTX is a well known chemistry with several routes being available. As the lignin conversion process produces predominantly phenols, the conversion of phenols by the known routes is considered well within the scope of one of ordinary skill. Once the BTX (benzene, toluene, xylenes) is formed it can be passed to a conversion step to convert the BTX to terephthalic acid, react the terephthalic acid with ethylene glycol and make polyester resin and subsequently articles from polyester resin via stream (910). It is again well within the scope of one of ordinary skill to convert these products to terephthalic acid, react the terephthalic acid with ethylene glycol to make polyester resin and subsequently articles from the polyester resin such as films, trays, preforms, bottles and jars.

The subsequent conversion may be conducted at a site which is different from the site wherein the disclosed bio-based composition was produced.

EXPERIMENTAL

Lignin Feedstream Preparation

The experiments used a composition obtained from Arundo Donax as a starting raw material.

The raw material was subjected to a soaking treatment in water at a temperature of 155°C for 65 minutes then steam exploded at a temperature of 190°C for 4 minutes.

The steam exploded material and the liquids from soaking material were mixed together and subjected to enzymatic hydrolysis, fermentation to ethanol and distillation.

Detailed parameters used are considered not relevant for the experiments, provided that the percentage content of the composition is preserved.

The mixture of liquid and solids after distillation was pressed at 15 bar and at a temperature of 80°C to obtain a dense and compact solid, having a dry matter content of 55%, which is the lignin feedstream used in the experiments to produce the disclosed bio-based composition.

The lignin feedstream was subjected to a temperature lower than 0°C and kept frozen until experiments execution.

Compositions by weight percent on a dry basis of the starting ligno-cellulosic biomass and lignin feedstream are reported in table 1. The lignin feedstream comprises lignin, complex sugars (insoluble glucans and insoluble xylans which have not been solubilized), ashes and other compounds. Compositions were determined according to standard analytical methods listed at the end of experimental section. Ligno-cellulosic biomass (dry Pre-treated Lignin feedstream

weight %) (dry weight %)

Lignin 22.6 49.0

Insoluble glucans 37.5 30.6

Insoluble xylans 19.3 4.9

Ash 6.3 8.2

Other compounds 14.3 7.3

Table 1. Compositions of the starting ligno-cellulosic biomass and pre-treated lignin feedstream used in conversion experiments.

Lignin conversion procedure

The following procedures were applied to all the experiments, unless differently specified.

De-ionized water was added to the pre-treated lignin feedstream to reach the final composition concentration in the slurry planned in each experiment. The slurry was inserted into a blender (Waring Blender, model HGBSS6) and thoroughly mixed intermittently (e.g. pulsed on for 30 sec, left off for 30 sec) for 10 min to reach a homogeneous slurry. The homogeneity of the slurry was evaluated by eye.

The slurry was inserted into a mix tank with constant agitation. The mix tank was a stainless steel, dish bottom tank with a bottom discharge port connected to a Chandler Quizix QX dual syringe pump equipped with full port ball valves, connected to the lignin conversion reactor. The pump discharge was connected to the reactor with tubing.

The lignin conversion reactor was a Parr 4575 reactor equipped with a dual 45° pitched turbine blade, cooling coil, separate gas and slurry feed ports and a discharge dip tube. The reactor was charged with water and catalyst (Johnson Matthey A-5000 sponge catalyst) according to the experimental conditions of each experiment and sealed. The weight of catalyst introduced is indicated as the ratio between the weight of the catalyst and the weight of dry matter of the lignin-rich composition added to the lignin conversion reactor in one residence time. Hydrogen at a temperature of 20°C was inserted into the lignin conversion reactor to reach a pressure of 48.3 bar. The lignin conversion reactor was heated to a temperature corresponding to 90% of the reaction temperature and continuous flow of Hydrogen was started into the lignin conversion reactor. The lignin conversion reactor was connected to a products receiver, maintained at 25°C. The pressure was measured by means of a pressure transducer (Ashcroft Type 62) connected to the lignin conversion reactor and controlled by means of a back-pressure regulator (Dresser Mity Mite 5000, model 91) placed downstream of the products receiver. Temperature was increased to the reaction temperature and the flow of slurry comprised of lignin was introduced into the lignin conversion reactor. The slurry flow rate was calculated for obtaining the residence time of the lignin feed in the reactor in each experiment at the operating conditions. After a time corresponding to 3 residence times steady conditions were considered to be reached and solid and liquid reaction products were collected into the receiver for a time corresponding to 1 residence time. The receiver was depressurized to atmospheric pressure, the non-gaseous reaction products were extracted with methyl tert-butyl ether organic (MTBE) solvent, filtered, and the liquid phases were separated by a separatory funnel. The organic phase separated in the separatory funnel consists of the bio-based composition

Experiments were conducted according to the described procedure. Experimental parameters are reported in Table 2.

Table 2. Experimental parameters of the lignin conversion tests.

Characterization of the bio-based composition Extraction of oxygenated aromatic fraction

The bio-based composition obtained from lignin conversion experiments is rich in phenols, which are weak acids due to the acidity of the phenolic proton. A strong aqueous base wash forms phenol salts that are quite water soluble. This test was performed by dissolving the bio-oil in MTBE and adding 3 consecutive aliquots of 2N NaOH. Specifically, the first aliquot of base was added to a separatory funnel already charged with the oil solution in MTBE. After shaking vigorously for l-2min, the funnel was placed in a ring stand to allow the layers to separate. Both layers were extremely dark and it was difficult to observe the phase boundary. After separating the bottom aqueous layer, the second charge of NaOH was added and the process was repeated. It was observed that the color of the bottom layer became progressively lighter after each NaOH charge, up to the point where the color was a pale yellow. The MTBE layer was dried over MgS0 , filtered and evaporated to obtain a weight fraction of the total oil (herein called the non-base extractable fraction). The aqueous layers were combined, and fresh MTBE was added. To this mixture, 6N HCI was added until the aqueous layer pH is <5. At this point, the brown color moved from the aqueous layer to the top ether layer. The layers were separated and the aqueous layer was washed one more time with fresh MTBE. The two MTBE layers were combined, dried over MgS0₄, filtered and evaporated to obtain a weight fraction (herein called the base extractable fraction).

The portion of the bio-oil extracted by base was greater than 70% of the original weight in all the experiments, while the non-extractable portion accounted for the remaining portion. After separating the two fractions and removing the solvent, it was further observed that viscosity of the two fractions was quite different. The oxygenated aromatic fraction had a viscosity resembling motor oil, while the other fraction appeared to be solid and waxy.

Molecular weight distribution

The bio-based composition was characterized by gel permeation chromatography (GPC), also known as size exclusion chromatography. The use of this technique allows for reporting mass distribution and average molecular weight (M). The average molecular weight can be defined as number average molecular weight (M„) or weight average molecular weight (M_w). The number average molecular weight is the statistical average molecular weight, weighted according to the number of molecules in the sample. On the other hand, the weight average molecular weight takes into account the molecular weight of a chain in determining contributions to the average M. The more massive the chain, the more the chain contributes to M_w. Finally, the polidispersivity index (D) is used as measure of the broadness of a molecular weight distribution of a polymer and is defined as M_w/M_n.

The number average (M_n) and weight average (M_w) molecular weights as well as the polydispersity (D) values for the phenol oils produced are summarized in Table 3. The distribution of the mass fraction (%) was grouped into three categories, which correspond to monomeric aromatic compounds (molecular weight <= 210Da), dimeric aromatic compounds (molecular weight greater than 210Da and less than or equal to 420Da), and heavier aromatic compounds (molecular weights greater than 420Da). Table 3. Mass distribution analysis for lignin conversion products of Table 2, Experiments 1, 2, 3, and 4.

The percent standard deviation error within 95% of confidence range, was 7% for M_n and 15% for M_w. This analysis indicates also that M_n calculated was equal to ca. 300 Da (comparable to dimers MW), while M_w is approximately 600 Da.

Gas Chromatography / Mass spectroscopy (GC/MS)

The bio-based compositions were analyzed by GC/MS. The monomeric phenolic compounds of all the bio-based compositions produced, expressed as percent area of the curve, are reported in Table 4. Total monomeric phenolic compounds account for more than 60% of the total area.

Table 4. Monomeric phenolic compounds of the bio-based compositions (exp 1 to 4)

Relative Amount (Area % of GC/MS)

Peak ID Exp 1 Exp 2 Exp 3 Exp 4

Phenol, 2-methoxy-4-propyl- 11.94 8.03 7.69 7.8

Propyl Syringol 10.32 8.6 4.58 6.65

Phenol, 4-ethyl-2-methoxy- 9.25 9.34 14.79 13.29

Phenol, 4-ethyl- 8.85 8.18 8.87 7.68

Phenol, 2-methoxy- 5.57 13.46 14.73

Ethyl Syringol 4.38 Benzene, l,2,3-trimethoxy-5-

4.27 7.41 6.4 5.38

methyl-

Phenol, 2,6-dimethoxy- 3.45 4.56 4.46

Phenol 2.13 2.81 4.42 4.74

Phenol, 4-methyl- 1.21 1.16

Phenol, 2-methoxy-4-methyl- 1.74 1.97 2.27 2.31

2,6 Dimethoxy-4-methylphenol 1.7 1.48 1.67

Phenol, 4-methyl- 1.25 1.05

1,2,4-Trimethoxybenzene 2.16

Naphthalene, 2,7-dimethyl- 1.18 1.17

Benzene, l-methyl-3-(l-

1.17 1.47

methylethyl)-

Ethyl benzene 1.17

Other phenols 3.88 3.4 3.28 1.34

Total Phenols 60.9 60.1 73.2 71.7

Acidity of the bio-based composition

Acidity of the bio-based composition of experiment 1 was measured according to method BS EN 14104, which resulted to be 27 mg KOH/g.

Stability of the bio-based composition

The bio-based composition of experiments 1 to 4 were stored in closed jars and aged at 25°C to check for stability against re-polymerization.

Table 5 reports the molecular weight distribution analysis of the freshly produced bio-based composition, a 2 month-aged and 1 year-aged bio-based composition of experiment 1. The analysis was repeated after 6 months and 1 year, giving the same composition within the experimental error (1%)

Similar results were obtained for the other bio-based compositions. Table 5. Molecular weight distribution of fresh oil and aged oil.

Analytical methods GC-MS analytical procedure

The composition of liquid products were determined by means of Agilent 7890 Gas chromatogram and Agilent 5975C Mass Detector, according to the following procedure and parameters.

Injector parameters in the Gas chromatogram:

Injection volume: 2 ul

Pulsed spilt injection

Injection pulsed pressure: 50 psi for 0.5 min

Temperature: 220°C.

Pressure: 20.386 psi

Septum purge: 3 ml/min

Split ratio: 10:1

Split flow 13 ml/min

Analytical Column:

Column: Restek RXI-5Sil MS, 30 meter, 0.25 mm ID, 0.5 urn df Flow (He): 1.3 ml/min MSD transfer line: (mass detector)

Temperature profile: 280°C. for entire run

Column transfer line: HP- 101 methyl siloxane-101 methyl siloxane: 12 m*200 um*0.25 urn Oven Parameters: (connected to the column)

40°C for 1 min

12°C/min to 220°C. for 0 mins

30°C/min to 300°C. for 17 mins

Detector Parameters:

Temperature: 310°C.

H₂ flow: 45 ml/min

Air flow: 450 ml/min

Makeup flow: 26.730 ml/min

MS Acquisition Parameters:

EM voltage: 1871

Low mass: 10

High mass: 350.00

Threshold: 25

# samples: 3

MS source: 230°C.

MS quad: 150°C. Products and related percentage content relative to the weight of liquid products were identified by means of NIST 2008 peak identification software. Only products corresponding to an area greater than 1% of the whole spectrum area are reported.

Gel permeation chromatography procedure

Molecular weight distribution analysis was performed by using an Agilent 1100 series HPLC equipped with an Agilent PLgel 3 μιη 250x4.6 mm (100 A) column maintained at 35°C, and a VWD detector. The injection volume was 0.020 ml and THF was the mobile phase with a flow rate of 0.5 mL/min.

Samples were dissolved at around 1 mg/mL in THF and filtered with 0.22 μπι filters before injection.

The GPC system was calibrated with polystyrene standards in a molecular weight range from 162 to 4190 g*mol-l. The weight average molecular weight (M_w), number average molecular weight (M_n), and molecular weight polydispersity of the samples were determined utilizing the linear relationship between molar mass and elution volume.

To aid in comparing molecular weight distributions among samples, mass fractions at 3 specific molecular masses were reported: 210 Da (maximum monomer phenol unit MW), 420 Da (Maximum dimer MW), and more than 420 Da (heavies MW).

Finally, analyses were performed at 254 nm to minimize the background absorption of THF. UV scan of the bio-oil shows a maximum peak near that wavelength while THF has its absorption minimum. It should also be mentioned that at 254 nm, neither aliphatic chains (UV peak at less 220 nm) nor sugar chains are able to be detected.

Claims

1. A bio-based composition derived from a lignin of a ligno-cellulosic biomass having an acidity which is less than 80 mg KOH/g, said bio-based composition comprising at least 50% by weight of aromatic compounds comprising monomeric aromatic compounds and non-monomeric aromatic compounds, said monomeric compounds having a molecular weight less than 210gr/mole, and wherein the amount of monomeric aromatic compounds does not decrease by more than 2% of the aromatic compounds by weight after storing the composition for a time between 1 week and 1 year in sealed conditions.

2. The composition of claim 1, wherein the total amount of monomeric aromatic compounds is in a range between 10% and 40% of the aromatic compounds by weight.

3. The composition of any of claims 1 to 2, wherein the monomeric aromatic compounds comprise

monomeric phenolic compounds, and the total area of the monomeric phenolic compounds under a GC/MS curve of the bio-based composition is within the range between 40% and 90% of the total area under the GC/MS curve.

4. The composition of any of claims 1 to 3, wherein the aromatic compounds comprise non-oxygenated aromatic compounds selected from the group consisting of benzene, toluene and xylene, or a mixture thereof.

5. The composition of any of claims 1 to 4, wherein the total amount of non-oxygenated aromatic

compounds is less than 5% of the composition by weight.

6. The composition of any of claims 1 to 5, wherein the total amount of the aromatic compounds is at least a value selected from the group consisting of 60%, 70%, 80% and 90% of the composition by weight.

7. The composition of any of claims 1 to 6, wherein the total amount of monomeric aromatic compounds is a value in a range selected from the group consisting of between 15% and 35%, and between 20% and 30% of the aromatic compounds by weight.

8. The composition of any of claims 1 to 7, wherein the total area of the monomeric phenolic compounds under a GC/MS curve of the bio-based composition is a value in a range selected from the group consisting of between 40% and 80%, between 45% and 75% , and between 50% and 70% of the total area under the GC/MS curve.

9. The composition of any of claim 1 to 8, further having an acidity which is less than a value selected from the group consisting of 70, 50, 30 and 20 mg KOH/g of the composition.

10. The composition of claim 9, wherein the percent amount of total carboxylic acids is less than a value selected from the group consisting of 1%, 0.5%, 0.3%, and 0.1% by weight of the composition.

11. The composition of claim 10, wherein the percent amount of total inorganic compounds is less than a value selected from the group consisting of lOOOppm, 5000ppm, 3000ppm, 2000ppm, and lOOOppm by weight of the composition.

12. The composition of any of claim 1 to 11, wherein the amount of monomeric aromatic compounds does not decrease by more than a value selected from the group consisting of 1.5%, 1.0%, and 0.5% of the aromatic compounds by weight after storing the composition for a time between 1 week and 1 year in sealed conditions.

13. The composition of any of claim 1 to 12, wherein the amount of monomeric aromatic compounds does not decrease by more than 2% of the aromatic compounds by weight after storing the composition for a time selected from the group consisting of 2 months, 4 months, 6months and 1 year at 25°C in sealed conditions.

14. A continuous conversion process for converting a lignin of a ligno-cellulosic biomass, comprising the steps of:

a. introducing a slurry comprised of lignin into a lignin conversion reactor

b. Converting at least a portion of the lignin of the pre-treated ligno-cellulosic biomass feedstock into first lignin conversion products by contacting the lignin with hydrogen in the presence of a first catalyst at a lignin conversion temperature, c. Removing the first lignin conversion products from the lignin conversion reactor, wherein the lignin conversion products comprise the composition of any of claims 1 to 13.

15. The process according to claim 14, wherein converting the lignin is done at a lignin conversion

temperature in the range selected from the group consisting of 190°C to 370°C, 210°C to 370"C, 220°C to 360°C, 240°C to 360°C, 250°C to 360°C, 280°C to 360°C, 290°C to 350°C, and 300°C to 330°C.

16. The process according to any of claims 14 to 15, wherein converting the lignin is done at a lignin conversion pressure selected from the group consisting of 70 bar to 300 bar, 80 bar to 245 bar, 82 bar to 242 bar, 82 bar to 210 bar, 90 bar to 207 bar and 90 bar to 172 bar.

17. The process of any of claims 14 to 16, wherein at least a portion of the hydrogen is derived from a hydrogen donor.

18. The process of any of claims 14 to 17, wherein the first catalyst comprises a sponge elemental metal catalyst.

19. The process of any of claims 14 to 17, wherein the sponge elemental catalyst comprises a metal selected from the group consisting of palladium, platinum, nickel, ruthenium, rhodium, molybdenum, cobalt, and iron.

20. The process of any of process of any of claims 14 to 19, wherein at least a portion of the composition is further catalytically converted to second lignin conversion products after being stored for a time greater than 1 day and less than 2 years, wherein the percent amount by weight of total aromatic compounds comprised of benzene, toluene and xylene in the second lignin conversion products is greater than in the first lignin conversion products.