METHOD FOR OBTAINING A STABLE LIGNIN: POLAR ORGANIC SOLVENT COMPOSITION VIA MILD SOLVOLYTIC MODIFICATIONS

Abstract

A process the production of a crude liquid lignin oil (CLO), the process includes the steps of providing a lignin-rich solid feedstock and subjecting the lignin-rich solid feedstock to a treatment in a polar organic solvent in the absence of an effective amount of added reaction promoter, such as a heterogeneous and/or homogeneous catalyst and/or hydrogen, and providing a lignin composition, the treatment includes a step of contacting the lignin-rich solid feedstock with a polar organic solvent under operating conditions of an operating temperature up to 210? C., an operating pressure lower than 50 bar and a residence time up to 240 minutes, wherein the ratio (w/v) of lignin (in lignin-rich feedstock) to polar organic solvent ranges between 1:1.5 and 1:15, or between 1:2 and 1:10 or between 1:2 and 1:5.

Claims

1. A process for the production of a crude liquid lignin oil (CLO), comprising the steps of: providing a lignin-rich solid feedstock and subjecting the lignin-rich solid feedstock to a treatment in a polar organic solvent in the absence of an effective amount of added reaction promoter, that is one or more of a heterogeneous catalyst, homogeneous catalyst, and hydrogen, and providing a lignin composition, said treatment comprises a step of contacting said lignin-rich solid feedstock with a polar organic solvent under operating conditions of an operating temperature up to 250? C., an operating pressure lower than 50 bar and a residence time up to 240 minutes, wherein the ratio (w/v) of lignin (in lignin-rich feedstock) to polar organic solvent ranges between 1:2 and 1:15 g/ml.

2. The process according to claim 1, wherein the operating temperature ranges between 100-200? C., and wherein the ratio (w/v) of lignin (in lignin-rich feedstock) to polar organic solvent ranges between 1:2 and 1:10 g/ml.

3. The process according to claim 1, wherein the operating pressure ranges between 2-50 bar, and wherein the residence time ranges between 10-120 minutes.

4. The process according to claim 1, wherein the polar organic solvent is a polar organic solvent having at least one oxygen group chosen from the group of alcohols, ketones and esters, and combinations thereof and wherein the melting temperature of the solvent is below 50? C.

5. The process according to claim 1, wherein the polar organic solvent is methanol, ethanol, n-propanol, i-propanol, t-butanol, i-butanol, phenol, a diol methyl acetate, ethyl acetate, acetone or methyl ethyl ketone, or a combination thereof.

6. The process according to claim 1, wherein the polar organic solvent is ethanol, methanol, n-propanol, i-propanol, t-butanol, i-butanol, methyl acetate, ethyl acetate, acetone or methyl ethyl ketone, or a combination thereof.

7. The process according to claim 1, wherein the amount of water present is less than 15 wt. % of the sum of the lignin-rich solid feedstock and polar organic solvent.

8. The process according to claim 1, wherein the process contains a second stage, wherein the suspended lignin stream obtained from the previous step is subjected to a partial removal of the polar organic solvent from the mixture and optionally the solvent is replaced by another polar solvent having an oxygen atom.

9. A medium crude lignin composition (CLO-M), comprising: 2.9-30 wt. % of lignin, and a polar organic solvent.

10. The composition according to claim 9, wherein the lignin has a weight average molecular weight (Mw) in a range of 1000-2000 dalton with a polydispersity index in a range of 2.1-3, and wherein the lignin composition has a kinematic viscosity at a shear rate of 300 (1/s) @40? C. between 1.5 and 20.

11. The composition according to claim 9, wherein the polar organic solvent is selected from ethanol and methanol.

12. A high crude lignin composition (CLO-H), comprising: 30-80 wt. % of lignin, and a polar organic solvent.

13. The composition according to claim 12, wherein the lignin has a weight average molecular weight (Mw) in a range of 1000-2000 dalton with a polydispersity index in a range of 2.1-3, and wherein the lignin composition has a kinematic viscosity at a shear rate of 300 (1/s) @ 40? C. between 20 and 200 cST.

14. The composition according to claim 12, wherein the polar organic solvent is selected from the group consisting of ethanol and methanol.

15. A method, comprising the steps of: using the crude liquid lignin obtained in the process according to claim 1, as a fuel or as a chemical component for downstream applications.

16. The process according to claim 15, wherein the operating temperature ranges between 140-200? C., wherein the ratio (w/v) of lignin (in lignin-rich feedstock) to polar organic solvent ranges between 1:2 and 1:5 g/ml, wherein the operating pressure ranges between 5-40 bar and wherein the residence time ranges between 20-90 minutes.

17. The process according to claim 16, wherein the operating temperature ranges between 160-199?C, and wherein the residence time ranges between 21 and 40 minutes.

18. The process according to claim 5, wherein the melting temperature of the solve is below 40? C., wherein the diol is one or more of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1.3-propanediol, butanediol, hexanediol, and glycerol, and wherein the amount of water present is less than 10 wt. % of the sum of the lignin-rich solid feedstock and polar organic solvent.

19. The composition according to claim 9, wherein the composition comprises 10 and 30 wt. % lignin, wherein the lignin composition has a kinematic viscosity at a shear rate of 300 (1/s) @40? C. between 1.8 and 10 (cST).

20. The composition according to claim 12, wherein the composition comprises 50 and 75 wt. % lignin, wherein the lignin composition has a kinematic viscosity at a shear rate of 300 (1/s) @40? C. between 20 and 200 (cST).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to more fully understand the manner in which the above-recited and other advantages and objects of the invention are obtained, a more particular description of the invention briefly described above will be rendered by reference to a specific embodiment thereof illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

[0061] FIG. 1 is an example of a flow diagram of a two staged method for producing a stable 1:1 (w/v) lignin-to-ethanol CLO.

[0062] FIG. 2 shows the effect of shorter reaction times in product distribution (reaction conditions: 200? C., lignin-to-ethanol ratio 1:5 w/v).

[0063] FIG. 3 shows the effect of shorter reaction times in CLO density and selectivity to CLO (reaction conditions: 200? C. lignin-to-ethanol ratio 1:5 w/v).

[0064] FIG. 4 shows the selectivity of the lignin solvolysis process as function of reaction temperature under the Experimental conditions: Lignin: ethanol feeding ratio (1:5 w/v), reaction time 30 min.

[0065] FIG. 5 shows the ethanol losses and char formation as function of the reaction temperature under the following experimental conditions: Lignin: ethanol feeding ratio (1:5 w/v), reaction time 30 min.

[0066] FIG. 6 shows the selectivity of the formation of CLO and density (concentration lignin in the CLO) as a function of reaction temperature under the experimental conditions: Lignin: ethanol feeding ratio (1:5 w/v), reaction time 30 min.

[0067] FIG. 7 shows the selectivity of the lignin solvolysis process as function of reaction temperature between 200 and 250? C. under the Experimental conditions: Lignin: ethanol feeding ratio (1:5 w/v), reaction time 30 min.

[0068] FIG. 8 shows the selectivity of the lignin solvolysis process as function of reaction temperature under (Experimental conditions) Lignin: methanol feeding ratio (1:5 w/v), reaction time 30 min.

[0069] FIG. 9 shows a GPC curve of the solvolysis of lignin P1000 at 200 celc under different reaction times.

[0070] FIG. 10 shows a GPC curve of the solvolysis of lignin P1000 at different temperatures (50-100-200? C. under a reaction time of 30 minutes.

[0071] FIG. 11 shows a GPC curve of the solvolysis of lignin P1000 at different lignin:ethanol ratios (1:15, 1:10 and 1:5) at 200? C. and 30 minutes reaction time.

[0072] FIG. 12a shows the Kinematic viscosity (cST @40? C.) of CLO-M and CLO-H obtained from the reaction of lignin in ethanol at 120? C.

[0073] FIG. 12b shows the Kinematic viscosity (cST @40? C.) of CLO-M and ethanol from FIG. 12a.

[0074] FIG. 13a shows the Kinematic viscosity (cST @40? C.) of CLO-M and CLO-H obtained from the reaction of lignin in ethanol at 200? C.

[0075] FIG. 13b shows the Kinematic viscosity (cST @40? C.) of CLO-M and ethanol obtained FIG. 13a.

DETAILED DESCRIPTION OF THE INVENTION

[0076] In all Examples the 1:1 w/v ratio refers to the actual final amount of reaction lignin product suspended/dissolved in the polar solvent.

Example 1

[0077] In the first stage of the present process, sulfur-free P1000 soda lignin feed material is subjected to a partially thermo-catalyzed depolymerization in the presence of a reaction medium, for example ethanol, via a mild solvolysis process. Lignin is converted to a suspension by simple dissolution in ethanol, in operating temperatures beneath 200? C., pressure beneath 50 bar and residence time up to 60 min. The solvolysis mixture is first subjected to a solid/liquid separation step such as filtration (2.7 ?m) or centrifugation to separate insoluble solids. These solids typically comprise a mixture of char and undissolved lignin, depending on the operating temperature, and typically have considerable heating value as a solid fuel. Lignin is actually fractionated in ethanol and partially depolymerized to selectively produce low yields (?5 wt. %) of C7-C10 alkylphenols and mostly higher molecular weight lignin oligomers. In the second stage of the present process, the liquid mixture of lignin and ethanol (CLO-M, FIG. 1) is subjected to an extra separation step, by removal of ethanol via vacuum distillation. Partially, ethanol is distilled from the mixture, until the final product (CLO-H) has approximately a 1:1 w/v lignin: ethanol ratio (production of CLO 1:1, FIG. 1). The amount of ethanol that is being removed is calculated in accordance with the amount of lignin that is suspended in the reaction mixture (first-step). Any further removal of solvent from the reaction mixture, is found that will cause precipitation of the suspended lignin and finally the separation of the two feed streams. The high purity distilled ethanol can be recycled back to the first stage of the process. The stable CLO-H 1:1 product can be used as a sulfur-free marine fuel as is, or as a chemical intermediate for further catalytic upgrade in a centralized location in a number of key organic compounds.

Example 2

[0078] Two cases from FIG. 2 (entries 6 & 7) were chosen in order to proceed with the production of a CLO-H 1:1 (g/ml). For both cases a 4 L batch autoclave reactor was used in order to execute the solvolytical depolymerisation of lignin (first-step). The chemical intermediate of this reaction is the CLO-M, a mixture of lignin and ethanol with ratio depending on the conversions obtained in the solvolysis step. Later, CLO-M was subjected to vacuum distillation, where partial removal of ethanol occurs. Distillation stopped at the point where lignin and ethanol were a stable suspension, and lignin did not precipitate. This critical point found to be close to 1:1 (g/ml) lignin-to-ethanol ratio. In FIG. 2, the mass balances of all streams are presented. The purity of the recovered ethanol was 99.6 wt. % while the ethanol losses in the process where 5-7 wt. %. The losses were due to condensation issues in the reactor tubing system. Blank experiments with ethanol only were performed and resulted on similar solvent losses.

Example 3

[0079] Sulfur-free P1000 soda lignin feed material is subjected to a thermolysis depolymerisation process in the presence of a reaction medium. 13.3 gr of lignin were added in a 100 ml batch reactor together with 40 ml of solvent (50/50 ethanol/methanol). The reactor was purged with N.sub.2 and the pressure was set to 10 bar (Pc). The reaction temperature was set to 200? C., and the residence time was 30 min and the reaction pressure was 50 bar. After reaction, the reactor was cooled down to room temperature, within 30 min using an ice-bath. The solvolysis slurry mixture, was first subjected to a solid/liquid filtration step (2.7 ?m filter paper) using a vacuum air filter pump. The solid residue is typically composed by char. The filtrate (CLO-M) is a liquid mixture of solvent and suspended lignin. The density of the CLO-M was experimentally measured and had the value of 0.8725 g/ml. The solid residue was found to be 5.9573 gr. In order to verify the lignin concentration in the CLO-M, 1 ml of sample was subjected to vacuum distillation. It was found that 0.22 gr of lignin were dissolved in 1 ml of CLO-M. The final volume of CLO-M was 34 ml and accordingly lignin conversion reached 56 wt. %. After knowing the exact lignin content of CLO-M and using the measured density of the mixture, the amount of solvent was calculated. In order to obtain a 1:1 w/v lignin:solvent ratio, 1 ml of solvent per 1 gr of lignin dissolved was required. Finally, 14.23 ml of solvent were removed from 33 ml of CLO-M with vacuum distillation, in order to end up with a heavy crude lignin oil suspension with 1:1 w/v ratio (CLO 1:1).

Example 4

[0080] The same procedure as Example 3 was followed except that Kraft lignin was used now as lignin feed material. 13.3 gr of lignin were added in a 100 ml batch reactor together with 40 ml of methanol. The reactor was purged with N.sub.2 and the pressure was set to 10 bar (Pc). The reaction temperature was set to 200? C., the residence time was 30 min and the reaction pressure was 50 bar. After reaction, the reactor was cooled down to room temperature, within 30 min using an ice-bath. The solvolysis slurry mixture, was first subjected to a solid/liquid filtration step (2.7 ?m filter paper) using a vacuum air filter pump. The solid residue is typically composed by char. The filtrate (CLO-M) is a liquid mixture of solvent and suspended lignin. The density of the CLO-M was experimentally measured and had the value of 0.8500 g/ml. In order to verify the lignin concentration in the CLO-M, 1 ml of sample was subjected to vacuum distillation. It was found that 0.16 gr of lignin were dissolved in 1 ml of CLO-M. The final volume of CLO-M was 34 ml and accordingly lignin conversion reached 40 wt. %. After knowing the exact lignin content of CLO-M and using the measured density of the mixture, the amount of solvent was calculated. In order to obtain a 1:1 w/v lignin:solvent ratio, 1 ml of solvent per 1 gr of lignin dissolved was required. Finally, 22.4 ml of methanol were removed from 34 ml of CLO-M with vacuum distillation in order to end up with a heavy crude lignin oil suspension with 1:1 w/v ratio (CLO 1:1).

Example 5

[0081] In this example enzymatic lignin (EL) from a furfural plant in China was used as lignin feed material. 100 gr of lignin were added in a 4000 ml batch reactor together with 500 ml of ethanol. The reactor was purged with N.sub.2 and the pressure was set to 10 bar (Pc). The reaction temperature was set to 200? C., the residence time was 30 min and the reaction pressure was 55 bar. After reaction, the reactor was cooled down to room temperature, within 4 hours. The solvolysis slurry mixture, was first subjected to a solid/liquid filtration step (2.7 ?m filter paper) using a vacuum air filter pump. The solid residue wet cake, was dried to remove any solvent left and weighted (31.92 gr). The filtrate (CLO-M) is a liquid mixture of solvent and suspended lignin. The density of the CLO-M was experimentally measured and had the value of 0.8335 g/ml. In order to verify the lignin concentration in the CLO-M, 10 ml of sample was subjected to vacuum distillation. It was found that 1.46 gr of lignin were dissolved in 10 ml of CLO-M. The final volume of CLO-M was 480 ml and accordingly lignin conversion reached 67.2 wt. %. After knowing the exact lignin content of CLO-M and using the measured density of the mixture, the amount of solvent was calculated. In order to obtain a 1:1 w/v lignin:solvent ratio, 1 ml of solvent per 1 gr of lignin dissolved was required. Finally, 329 ml of ethanol were removed from 470 ml of CLO-M with vacuum distillation in order to end up with a heavy crude lignin oil suspension with 1:1 w/v ratio (CLO 1:1).

[0082] The summary of the process conditions of examples 3-5 are shown in Table 1.

TABLE-US-00001 TABLE 1 summary of process conditions examples 3-5. Lignin CLO-M CLO 1:1 T (? C.)/ T Lignin:Solvent Conversion density volume Ex Lignin type Solvent P (bar) (min) ratio wt. % (g/ml) (ml) 3 P1000 50/50 200/50 30 1:3 56 0.8725 14 ethanol/ methanol 4 Kraft Methanol 200/50 30 1:3 40 0.8500 9 5 Enzymatic Ethanol 200/55 30 1:5 67 0.8335 130

Example 6

[0083] Different experiments have been performed according to example 1, whereby the temperature, reaction time and lignin to ethanol ratio have been varied. The experiments are summarized in Table 2.

TABLE-US-00002 TABLE 2 summary of experiments performed in example 6. Liquid Lignin:EtOH Lignin product Density Lignin in Entry ratio Temperature Time In conversion CLO-M CLO-M CLO-M (g/mL) (? C.) (h) (g L/g EtOH) (wt. %) (ml) (g/ml) (wt %) 1 1:15 200 4 2.66/31.2 75 37.4 0.8198 7.5 2 1:15 200 2 2.66/31.2 73 37 0.8155 6.5 3 1:15 200 1 2.66/31.2 72.5 37.1 0.8139 6.1 4 1:15 200 0.5 2.66/31.2 72.5 37.4 0.8109 5.4 5 1:10 200 0.5 4/31.2 65 37.3 0.8201 7.6 6 1:5 200 0.5 8/31.2 56 37.2 0.8505 15 7 1:5 120 0.5 8/31.2 49.8 37.1 0.8380 12 8 1:5 100 0.5 8/31.2 49.2 36.8 0.8398 12.5 9 1:5 50 0.5 8/31.2 34.9 37 0.8316 10.5 10 1:5 25 0.5 8/31.2 12.7 38 0.8005 2.9 11 .sup.1:2.5 200 0.5 16/31.2 42 36 0.8967 26.3 12 1:2 200 0.5 20/31.2 41 36.5 0.9146 30.7 13 1:1 200 0.5 31.2/31.2

[0084] The effect of the shorter reaction times is shown in FIG. 2: at longer reaction time the conversion to CLO increases, but also char formation increases. FIG. 3 shows that the selectivity for CLO increases upon increase of the reaction time, and thereby also the density of the CLO increases.

[0085] Molecular weights of the experiments have been measured, and the result is summarized in Table 3.

TABLE-US-00003 TABLE 3 total Average (PDA 254 nm) - Mw/Mn Mw/Mn Entry # Mn Mw (PDI index) Soda Lignin 531 1259 2.37 P1000 1 200 C._4 h_1:15 625 1674 2.68 2 200 C._2 h_1:15 579 1343 2.32 3 200 C._1 h_1:15 566 1334 2.36 4 200 C._30 min_1:15 538 1259 2.34 5 200 C._30 min_1:10 537 1229 2.29 6 200 C._30 min_1:5 560 1293 2.31 8 100 C._30 min_1:5 526 1120 2.13 9 50 C._30 min_1:5 472 1066 2.26

[0086] GPC analyses were performed by using a Shimadzu Prominence-I LC-2030C 3D apparatus equipped with two columns connected in series (Mixed-C and Mixed-D, polymer Laboratories) and a UV-Vis detector at 254 nm. The column was calibrated with Polystyrene standards. Analyses were carried out at 25? C. using THE as eluent with a flow rate of 1 ml/min. For the model compound analysis, an aliquot of 40 ?l solution was taken from the reaction mixture followed by removing the solvent by blowing with air under room temperature. The sample was dissolved with 1 ml THF (the concentration is ?2 mg/ml). For the lignin residue analysis, the sample was prepared at a concentration of 2 mg/ml. All the samples were filtered using 0.45 ?m filter membrane prior to injection. These procedures are in accordance with a publication of Emilie J.Siochi et al. in Macromolecules 1990, 23, 1420-1429.

[0087] The GPC graphs are represented in FIGS. 9-11. It is clearly shown that the reaction time and temperature have an influence on the low molecular weight components and also the high molecular weight components. This differences will have an influence on the kinematic viscosity of the CLO-M and CLO-H.

Experiment 7

[0088] Additional experiments were performed in order to show the effect of reaction temperature on the conversion of lignin, formation of char and selectivity to CLO. For this reason solvolysis has been performed at 6 different temperatures: 100? C.-150? C.-200? C.-250? C.-300? C.-350? C.

[0089] For all the experiments the mass balance for lignin is presented together with the distribution of different products (undissolved lignin, char (collected/or fouling, and lignin converted to CLO-M).

[0090] We focus on two important parameters: the ethanol losses (which were also measured after every reaction) and the fouling effect. As Char (fouling) we consider the amount of char that was formed and was stacked to the reactor and the stirrer. As Char (collected) we consider the amount of char formed and that could be easily removed from the reactor without the need of scratching the reactor and the stirrer. As Undissolved lignin we consider the amount of lignin that could dissolve in THF after the filtration step. Both Char (collected) and Char (fouling) were THF-insoluble residues.

[0091] The results are presented in FIG. 4.

[0092] In FIG. 4 the effect of reaction temperature in the lignin conversion and product distribution is presented. Also in this graph we see the importance of low reaction temperatures when we shift from diluted feeding ratios to high lignin loadings. What we observe in this graph is that at low temperatures (<200? C.) we prevent any fouling issues in the reactor. At temperatures above 250? C. the formed char is causing fouling problems in the reactor and the stirrer, fact that makes the realization of a continuous process challenging. Also at high temperatures the selectivity to CLO is dropping dramatically. At low temperatures, we can achieve high conversion of lignin into CLO-M, preventing any fouling issues and being able to remove any char/unconverted lignin for downstream combustion process and energy generation purposes.

[0093] The effect of ethanol losses and reactor fouling in relation to operation temperature, are depicted in FIG. 5. The ethanol losses are remaining in reasonable and acceptable levels in temperatures up to 200? C., but at elevated temperatures solvent losses up to 15 wt. % were measured. The fouling effect is crucial at higher temperatures, reaching even values of 60-70 wt. %. These two issues, we are hoping to solve with our IP. Solvent consumption is the main component of variable costs in every commercial process.

[0094] The trends of CLO density and selectivity to CLO in accordance with the operating temperature are presented in FIG. 6. The highest amount of lignin in the CLO (which is translated in density), for high lignin loadings, can be achieved at temperatures below 250? C. What is actually happening at high temperatures is that lignin is converted to char, causing fouling, which drops the selectivity to CLO. By maintaining low operating conditions, we can increase the yield of the CLO and at the same time ensure safe and efficient separation of the solid residue (char).

TABLE-US-00004 TABLE 4 results of experiment 7 Solvolysis Selectivity Unconv. Char Char Temperature CLO Lignin (collected) (fouling) (? C.) (wt. %) (wt. %) (wt. %) (wt. %) 100 39.8 44.6 13.51 0 150 50.26 33.62 14.12 0 200 64.24 16.75 17.01 0 250 24.25 6.38 2.85 64.19 300 22.81 4.29 4.15 63.88 350 18.62 1.16 6.95 68.5

Experiment 8

[0095] In experiment 7 we observed that in temperatures between 200 and 250? C., there is a sharp transition on the distribution of products, the lignin mass balances and the appearance of char (fouling) in the reactor and the decrease of selectivity to CLO. For that reason we decided to choose 3 more points in between in order to be able to understand this phenomenon. Three additional points were chosen (210, 220 and 240? C.) as it is shown in the FIG. 7. What we observe is that the reactor fouling due to char formation already starts to appear at 210? C., and continues to increase till 250? C. The conversion to CLO does not show any improvement during temperature rise, on the contrary, it starts slowly to decrease. In that case, at high lignin loadings, if we want to prevent any char fouling issues and at the same moment achieve high CLO yields, temperatures up to 200? C. should be chosen.

TABLE-US-00005 TABLE 5 results experiment 8 Solvolysis Selectivity Unconv. Char Char Temperature CLO Lignin (collected) (fouling) (? C.) (wt. %) (wt. %) (wt. %) (wt. %) 200 64.24 16.75 17.01 0 210 47.27 24.25 2.68 15.7 220 37.05 14 2.77 42.73 240 28.14 9.14 2.91 58.14 250 24.25 6.38 2.85 64.19

Experiment 9

[0096] In experiment 7, we performed several experiments with Ethanol as a solvent at different temperatures. In order to investigate the performance of methanol as a polar alcohol (cheaper solvent), we choose three temperatures (100, 200 & 300? C.) (see FIG. 8 for results).

[0097] In this example P1000 soda lignin was used as lignin feed material. 300 g of lignin were added in a 4000 ml batch reactor together with 1500 ml of methanol. The reactor was purged with N.sub.2 and the pressure was set to 10 bar (Pc). The reaction temperature was set to 200? C., the residence time was 30 min and the reaction pressure was 55 bar. After reaction, the reactor was cooled down to room temperature, within 4 hours. The solvolysis slurry mixture, was first subjected to a solid/liquid filtration step (2.7 ?m filter paper) using a vacuum air filter pump. The solid residue wet cake, was dried to remove any solvent. The filtrate (CLO-M) is a liquid mixture of solvent and suspended lignin to verify the lignin concentration in the CLO-M, 1 ml of sample was subjected to vacuum distillation. It was found that 0.1365 g of lignin were dissolved in 1 ml of CLO-M. The final volume of CLO-M was 1400 ml and accordingly lignin conversion reached 63.75 wt. %. After knowing the exact lignin content of CLO-M and using the measured density of the mixture, the amount of solvent was calculated. 1000 ml of CLO-M containing 136.5 gr of lignin, and based on the measured density, weighted 838 g. 838 g of CLO-M were subjected to vacuum distillation (40? C.), and 651 gr of methanol were recovered. Finally a heavy crude lignin oil suspension with 136.5 g of lignin and 47.77 g of methanol was obtained (CLO-H 1:0.35 w/w lignin:methanol).

Experiment 10

[0098] The kinematic viscosity has been determined of CLO-M and CLO-H blends in ethanol. * Viscosity measurements were performed, using the plate and cone technique, are conducted on a Physica MCR 302 rheometer at a temperature of 40? C.

[0099] The blends have been produced under different conditions: the first blend is produced at 120? C., the second blend at 200? C. results are summarized in Table 6.

TABLE-US-00006 TABLE 6 Solvolysis Viscosity @40? C. Product temperature (? C.) (cST) CLO-M 120 1.9 CLO-H (1:1) 120 82 CLO-M 200 1.9 CLO-H (1:1) 200 95

[0100] FIGS. 12 and 13 give the respective results.

Experiment 11 how to Obtain a Phenolic CLO-M

[0101] In this example P1000 soda lignin was used as lignin feed material. 4 g of lignin were added in a 100 ml batch reactor together with 40 ml of phenol. The initial lignin:phenol feeding ratio was 1:10 w/v. Phenol is a solid in room temperature, thus it was heated first to 41? C. before it was subjected to the reactor. At 41? C. the density of phenol was 1.04 g/ml. The reactor was purged with N.sub.2 and the pressure was set to 10 bar (Pc). The reaction temperature was set to 200? C., the residence time was 30 min and the reaction pressure was 40 bar. After reaction, the reactor was cooled down to 45? C., in order to keep phenol in a liquid form. Immediately, the solvolysis slurry mixture, was subjected to a solid/liquid filtration step (50 ml glass filter crucible por. 4/pore size 10-16 ?m) using a vacuum air filter pump. During the filtration process the glass filter was continuously heated with a heat gun in order to maintain phenol in the liquid form. The filtrate (CLO-M) is a liquid mixture of solvent and suspended lignin. The final volume of CLO-M was 41 ml and the density of the phenolic CLO-M was 1.0822 g/ml at 41? C. The solid residue after filtration was 1.77 gr and accordingly the selectivity of lignin to CLO-M reached 22.85 wt. %. Finally, the phenolic CLO-M contained 6.08 wt. % of lignin fragments.

Experiment 12 how to Obtain a Phenolic Based CLO-H (by Swapping Phenol after Stage II of the Process).

[0102] In this example P1000 soda lignin was used as lignin feed material. 300 g of lignin were added in a 4000 ml batch reactor together with 1500 ml of methanol. The reactor was purged with N.sub.2 and the pressure was set to 10 bar (Pc). The reaction temperature was set to 200? C., the residence time was 30 min and the reaction pressure was 55 bar. After reaction, the reactor was cooled down to room temperature, within 4 hours. The solvolysis slurry mixture, was first subjected to a solid/liquid filtration step (2.7 ?m filter paper) using a vacuum air filter pump. The solid residue wet cake, was dried to remove any solvent. The filtrate (CLO-M) is a liquid mixture of solvent and suspended lignin. To verify the lignin concentration in the CLO-M, 1 ml of sample was subjected to vacuum distillation. It was found that 0.1365 g of lignin were dissolved in 1 ml of CLO-M. The final volume of CLO-M was 1400 ml and accordingly lignin conversion reached 63.75 wt. %. After knowing the exact lignin content of CLO-M and using the measured density of the mixture, the amount of solvent was calculated. 1000 ml of CLO-M containing 136.5 gr of lignin, and based on the measured density, weighted 838 g. 838 g of CLO-M were subjected to vacuum distillation (40? C.), and 651 gr of methanol were recovered. Finally a heavy crude lignin oil suspension with 136.5 g of lignin and 47.77 g of methanol was obtained (CLO-H 1:0.35 w/w lignin:methanol). 100 g of the latest CLO-H were transferred in a 250 ml round bottom flask, placed in a heating bath (45? C.) and mixed with 65 g of pure phenol. The solution was stirred for 30 min and then was subjected to vacuum distillation (50? C.). 31 g of pure methanol could be finally weighted and recovered from the solution, as it was verified with GCMS. The weight concentration of the new phenolic based CLO-H was 65 g of lignin fragments, 65 g of phenol and around 3-4 g of methanol.