AT515486B1 - method - Google Patents

Abstract

The present invention relates to a process for the liquefaction of black liquor comprising a) mixing the black liquor with at least one hydrogen donor and with at least one catalyst and b) heating the mixture from step a) to a temperature in the range of 300 ° C to 600 ° C at a Total pressure of 10 to 800 bar over a period of 5 minutes to 12 hours, wherein the water content of the black liquor is reduced before mixing with the at least one hydrogen donor and the at least one catalyst.

Description

Description: The present invention relates to a process for the liquefaction of black liquor.

The liquefaction of carbonaceous materials, such as e.g. Coal has a long tradition and has been used on an industrial scale for over 100 years. In the course of liquefaction, the carbon compounds present in these materials are hydrogenated at high temperatures and pressures, and ideally with the aid of a catalyst, forming gaseous and liquid hydrocarbons. These can be obtained similarly as from liquid petroleum fractions and e.g. be used as fuels and fuels. In the course of liquefaction also heavy residues arise.

There are different methods for large-scale direct coal hydrogenation. When already known since 1913 Bergius method, z. B., coal is mixed with heavy oil. In addition, a catalyst is added to the mixture to increase the liquefaction efficiency. The liquefaction reaction occurs at a hydrogen pressure of 300 to 700 bar at a temperature between 400 ° C and 500 ° C.

There are also methods of liquefying carbonaceous materials by means of hydrogenating solvents. In these processes, the carbon compounds react with a solvent such as e.g. Tetralin, which can deliver hydrogen, wherein the coal is converted to hydrocarbons. The oxidized solvent can then be hydrogenated again to be used again. Currently, oxygen-rich compounds with a carbon content of less than 60% are not directly liquefied with hydrogenating solvents. In DE 3611340 a process is disclosed in which lignin and cellulosic biomass is mixed with a metallic catalyst and hydrogenated at a temperature of 300 to 400 ° C and a hydrogen partial pressure of 35 to 250 bar. The starting material used in this process is slurried prior to the process in an oil previously recovered by the same procedures.

Sugimoto Y et al. (Sekitan Kagaku Kaigi Happyo Ronbunshu 31 (1994): 60-62) relates to a process with the pyrolysis of cellulose-containing starting materials are hydrogenated at 350 ° C in the presence of tetralin and a catalyst.

In Berl et al. (Ind Eng Chem 33 (1941): 672-674), a process is disclosed in which bituminous starting materials are hydrogenated at 440 to 500 ° C and up to about 152 bar hydrogen pressure in the presence of a metal-containing catalyst.

In CN 1376766 a process for the hydrogenation of pyrolysis oil is described, in the course of which the oil is mixed with a catalyst and a hydrogen donor and at a hydrogen pressure of 20 to 150 bar and a temperature of 340 to 550 ° C for 10 is hydrogenated until 240 minutes.

The object of the present invention is to provide a method for the liquefaction of carbonaceous organic materials available, which overcomes the disadvantages of the prior art and makes it possible to liquefy even oxygen-rich materials.

The present invention relates to a process for the liquefaction of black liquor comprising: a) mixing the black liquor with at least one hydrogen donor and with at least one catalyst, and b) heating the mixture from step a) to a temperature in the range from 300 ° C to 600 ° C at a total pressure of 10 to 800 bar over a period of 5 minutes to 12 hours, wherein the water content of the black liquor is reduced prior to mixing with the at least one hydrogen donor and the at least one catalyst.

It has been found that the inventive method is particularly suitable to liquefy carbon in non-fossil materials having a carbon content of less than 60 wt .-% based on atro material. The entire liquefaction process can be carried out in conventional plants and reactors, which are also suitable for the liquefaction of coal.

The inventive method is preferably carried out in the presence of hydrogen, which is preferably introduced into the reactor before the hydrogenation. The reactor is pressurized, preferably using hydrogen.

The carbonaceous material is added to the hydrogenation (step b)) with a hydrogen donor. For example, hydrogen provided by the donor reduces the compounds in the material and is therefore important to the entire process. In order to optimize the liquefaction of the material, this is additionally mixed with a catalyst.

The term "non-fossil material having a carbon content of less than 60% by weight" includes all carbonaceous materials which are not of fossil origin such as lignite, coal or coal Such materials are preferably of vegetable origin and preferably comprise wood or parts This term also refers to products and intermediates of wood digestion processes. "Carbonaceous materials" in the context of the present invention are synonymous with "non-fossil materials having a carbon content of less than 60% by weight".

In the process according to the invention, preference is given to materials having a carbon content of less than 59% by weight, preferably less than 58% by weight, preferably less than 57% by weight, preferably less than 56% by weight, preferably less than 55 wt.%, preferably less than 54 wt.%, preferably less than 53 wt.%, preferably less than 52 wt.%, preferably less than 51 wt.%, preferably less than 50 wt. %, preferably less than 45 wt .-%, preferably less than 40 wt .-%, preferably less than 35 wt .-%, based on atro material used. The carbon content in the material used in the invention is preferably at least 5 wt%, more preferably at least 10 wt%, even more preferably at least 15 wt%, even more preferably at least 20 wt%, based on atro material.

The term "atro" as used herein means "absolutely dry". According to the invention, "Atro" refers to a material which has been dried at 105 ° C. for 24 hours. "Related to atro material" thus means that a value or measured value refers to "absolutely dry material".

In the process according to the invention, at least one hydrogen donor is added to the carbonaceous material. The amount of the at least one hydrogen donor in the mixture is from 1 wt% to 1000 wt%, preferably from 2 wt% to 800 wt%, more preferably from 5 wt% to 600 wt%. -%, more preferably from 10 wt .-% to 500 wt .-%, based on the total mixture.

Step b) of the process of the invention (the hydrogenation step) is carried out at a temperature in the range of 300 ° C to 600 ° C. Preferably, this step takes place at a temperature in the range of 350 ° C to 550 ° C, preferably 400 ° C to 500 ° C. The total pressure at which the hydrogenation of the carbon-containing compounds is carried out is 10 to 800 bar, preferably 20 to 700 bar, preferably 30 to 600 bar, preferably 40 to 500 bar, preferably 50 to 500 bar, preferably 50 to 400 bar, preferably 60 to 350 bar, preferably 70 to 350 bar, preferably 80 to 300 bar, preferably 80 to 280 bar, preferably 80 to 250 bar, preferably 80 to 200 bar. The pressure during the hydrogenation should be at least 10 bar, preferably at least 20 bar, even more preferably at least 50 bar.

The duration of hydrogenation of the carbonaceous material is 5 minutes to 12 hours, preferably 10 minutes to 10 hours, more preferably 15 minutes to 8

Hours, more preferably 20 minutes to 7 hours, even more preferably 30 minutes to 6 hours.

According to a preferred embodiment of the present invention, the at least one catalyst is selected from the group consisting of ferric oxide hydroxide (FeO (OH)), cobalt molybdenum sulfide, Fe 2 O 3, red mud and combinations thereof.

The catalyst used in the process may preferably have any shape, it being particularly preferred to add catalysts in particulate form (e.g., rod-shaped, circular) to the mixture. The size (length or diameter) of the particles is preferably 10 nm to 1 mm, preferably 10 nm to 500 pm, preferably 10 nm to 200 pm, preferably 10 nm to 200 pm, preferably 10 nm to 100 pm, preferably 10 nm to 5 pm, preferably 10 nm to 1 pm, preferably 10 nm to 500 nm , preferably 20nm to 200pm, preferably 20nm to 100pm, preferably 20nm to 50pm, preferably 20nm to 1pm, preferably 20nm to 500nm, preferably 30nm to 1mm, preferably 30nm to 500pm, preferably 30nm to 200pm, preferably 30nm to 10pm, preferably 30nm to 10pm , preferably 30nm to 5pm, preferably 30nm to 1pm, preferably 30nm to 500nm.

It is particularly preferred to use iron (III) oxide hydroxide (FeO (OH)) catalysts.

According to a further preferred embodiment of the present invention, the iron (III) oxide hydroxide is catalyst y-FeO (OH) (gamma-FeO (OH)), α-FeO (OH) (alpha-FeO (OH)) or a combination of them.

Particularly preferred is the use of y-FeO (OH) (gamma-FeO (OH)) as a catalyst, since this allows an even higher yield of liquid hydrocarbons from carbonaceous materials.

The catalyst in the mixture is preferably in an amount of 0.1 to 20 wt .-%, preferably from 0.5 to 17 wt .-%, more preferably from 1 to 15 wt .-%, based on the entire mixture, included.

In order to optimize the liquefaction process is in the process according to the invention a

Catalyst used. This catalyst is added in the aforementioned amount to the mixture comprising carbonaceous material and hydrogen donor. According to a preferred embodiment, the catalyst in the mixture in an amount of preferably 0.1 to 19 wt .-%, preferably 0.1 to 18 wt .-%, preferably 0.1 to 17 wt .-%, preferably 0.1 up to 16% by weight, preferably 0.1 to 15% by weight, preferably 0.1 to 14% by weight, preferably 0.1 to 13% by weight, preferably 0.1 to 12% by weight , preferably 0.1 to 11 wt .-%, preferably 0.1 to 10 wt .-%, preferably 0.1 to 5 wt .-%, preferably 0.1 to 2 wt .-%, preferably 0.5 to 20 wt .-%, preferably 0.5 to 19 wt .-%, preferably 0.5 to 18 wt .-%, preferably 0.5 to 16 wt .-%, preferably 0.5 to 15 wt .-%, preferably 0.5 to 14 wt .-%, preferably 0.5 to 13 wt .-%, preferably 0.5 to 12 wt .-%, preferably 0.5 to 11 wt .-%, preferably 0.5 to 10 Wt .-%, preferably 0.5 to 5 wt .-%, preferably 0.5 to 2 wt .-%, preferably 1 to 20 wt .-%, preferably 1 to 19 wt .-%, preferably 1 to 18 wt .-%, preferably 1 to 16 wt .-%, preferably 1 to 14 G ew .-%, preferably 1 to 13 wt .-%, preferably 1 to 12 wt .-%, preferably 1 to 11 wt .-%, preferably 1 to 10 wt .-%, preferably 1 to 5 wt .-%, preferably 1 to 2 wt .-%, preferably 2 to 20 wt .-%, preferably 2 to 19 wt .-%, preferably 2 to 18 wt .-%, preferably 2 to 17 wt .-%, preferably 2 to 16 wt %, preferably 2 to 15% by weight, preferably 2 to 14% by weight, preferably 2 to 13% by weight, preferably 2 to 12% by weight, preferably 2 to 11% by weight, preferably 2 to 10 wt .-%, preferably 5 to 20 wt .-%, preferably 5 to 19 wt .-%, preferably 2 to 11 wt .-%, preferably 5 to 18 wt .-%, preferably 5 to 17 wt. -%, preferably 5 to 16 wt .-%, preferably 5 to 15 wt .-%, preferably 5 to 14 wt .-%, preferably 5 to 13 wt .-%, preferably 5 to 12 wt .-%, preferably 5 to 11% by weight, preferably 5 to 10% by weight.

According to a preferred embodiment of the present invention, the black liquor is additionally mixed with sulfur or H2S.

The addition of sulfur to the carbonaceous material to be liquefied leads to a higher yield or to an increased liquefaction of the material. For carbonaceous materials which already contain sulfur (in any chemical form), the addition of additional sulfur or sulfur compounds may be dispensed with. If, however, carbonaceous materials in the process according to the invention, it is advantageous to add sulfur or sulfur compounds in order to increase the liquefaction rate again. In the mixture of the process according to the invention, sulfur or H 2 S is preferably present in an amount of from 0.1 to 20% by weight, preferably from 0.5 to 15% by weight, based on the total mixture.

When sulfur-containing compounds are used, the above-mentioned amount refers to the elemental sulfur occurring in the compound.

The mixture according to the invention comprising the carbonaceous material, the hydrogen donor and the catalyst can sulfur or H2S in an amount of preferably 0.1 to 20 wt .-%, preferably from 0.1 to 18 wt .-%, preferably from 0 From 1 to 15% by weight, preferably from 0.1 to 12% by weight, preferably from 0.1 to 10% by weight, preferably from 0.1 to 5% by weight, preferably from 0.5 to 12 wt .-%, preferably from 0.5 to 10 wt .-%, preferably from 0.5 to 5 wt .-%, based on the total mixture.

With the method according to the invention can not fossil carbonaceous materials are liquefied. The carbonaceous material may be selected from the group consisting of a by-product of alkaline cellulose production, acid cellulose production, the Organosolv process, the steam explosion process, and combinations thereof.

In many processes in which wood or plants is used as starting material, carbonaceous intermediate, waste or end products which comprise less than 60% by weight of carbon, based on the atro material, accumulate and are suitable for a Liquefaction are suitable. These carbonaceous products or materials can be used in the process according to the invention. Particularly preferably, lignin and / or hemi-cellulose-containing materials can be liquefied by the process according to the invention, which are obtained in the production of cellulose. Such methods are i.a. the sulphate process (alkaline cellulose production), the sulphite process (acid cellulose production), the organo-solv process and the steam explosion process, and there is also the organo-cell process, the asam process , the Formacell method and the Milox method. Carbon and especially lignin-containing materials derived from the sulphate process are particularly suitable.

The by-product of cellulose production, in particular of the alkaline cellulose production, which is used in the process according to the invention is black liquor.

Black liquor is an energy and lignin-rich by-product in cellulosic production and, after pulp separation, comprises residual lignin, hemicellulose, water and chemicals used for extraction. Black liquor usually has a solids content of 14-18%, with about 60 to 70% of the solids content being organic wood components.

The water content of the black liquor is preferably reduced before mixing with the at least one hydrogen donor and the at least one catalyst. In this step, compared to the black liquor obtained directly from the process, the water content may be at least 10%, preferably at least 20%, preferably at least 30%, preferably at least 40%, preferably at least 50%, preferably at least 60%, preferably at least 70%, preferably at least 80%, preferably at least 90%, preferably at least 95%, are reduced. Methods for reducing the water content in black liquor are known in the art and preferably comprise thermal methods.

According to a preferred embodiment of the present invention, the at least one hydrogen donor is selected from the group consisting of 1,2,3,4-tetrahydronaphthalene (tetra-imine), formic acid, salts of formic acid, 4,5-dihydropyrene, 9,10-dihydrophenanthrene and combinations thereof.

Particularly preferred is the use of tetrarhydronaphthalene (tetralin) as a hydrogen donor, which can serve as a solvent at the same time.

According to another preferred embodiment of the present invention, after the liquefaction of the lignin-containing material using tetrahydronaphthalene as the hydrogen donor naphthalene is recovered from the mixture and rehydrated to tetrahydronaphthalene.

The present invention will be further illustrated by, but not limited to, the following figures and examples.

FIG. 1 shows the molecular size distribution of liquefied kraft lignin according to FIG

Example 1.

FIG. 2 shows the molecular size distribution of liquefied kraft lignin according to FIG

Example 2. Figures 1 and 2 show that larger pieces of the carbonaceous material can be liquefied by the liquefaction method of the invention (Figure 1) and not, as in the alternative variant without catalyst (Figure 2; char. EXAMPLES:

Example 1: 30.5 g of a dried carbon and lignin-containing material of a black liquor ("Kraftlignin"; atro) was mixed with 1.42 g of gamma-FeOOH, 1.77 g of sulfur and 97.67 g of tetralin After reaching the target temperature of 425 ° C., hydrogenation was continued for 30 minutes at 180 bar with continuous addition of hydrogen at 180 bar After 30 minutes the reactor was cooled and weighed The gas formed was vented. The amount of gas formed was then determined, the solids were separated by filtration and the content determined The liquid wetted residue was extracted to determine the absolute solids content The carbon content of the solid after hydrogenation was 10% (before hydrogenation 35.39%). Thus, 78% of the carbon in the hydrocarbon fraction was liquefied and hydrogenated.

Table 1: Weighing weights [g]

Kraft lignin 30.5

Tetralin 97.67

Gamma FeOOH 1.42

Schwefel_1,77_

product weights

Final weight

Total mass 129.34

Total loss -0.1

Liquids 107,38

Solids 22.0

Gases 3.4 9.71 g of liquid hydrocarbon and oxygen-containing compounds were formed in the experiment. Example 2: 30.15 g of a dried carbon and lignin-containing material of a black liquor ("kraft lignin"; atro) was mixed with 90.02 g tetralin The mixture was transferred to a stainless steel autoclave which was capped and sealed with 50 bar hydrogen After the target temperature of 425 ° C. had been reached, hydrogenation was carried out for 30 minutes at 180 bar, followed by cooling and weighing the reactor for 30 minutes, the gas formed was vented The liquid-wetted residue was extracted to determine the absolute solids content, elemental analyzes of all feed streams were measured, the residual solids carbon content was 16.65%, and 72% of the carbon used was liquefied ,

weights

Table 2: Weighing weights [g]

Kraft lignin 30,15

Tetralin_90,02_

product weights

Final weight

Total mass 129.34

Total loss -0.9

Liquids 101.3

Solids 17.7

Gases 3,4

Claims (8)

claims A process for the liquefaction of black liquor comprising: a) mixing the black liquor with at least one hydrogen donor and with at least one catalyst and b) heating the mixture from step a) to a temperature in the range from 300 ° C to 600 ° C at a total pressure of 10 to 800 bar over a period of 5 minutes to 12 hours, wherein the water content of the black liquor is reduced before mixing with the at least one hydrogen donor and the at least one catalyst. 2. The method according to claim 1, characterized in that the at least one catalyst is selected from the group consisting of iron (III) oxide hydroxide (FeO (OH)), Cobaltmolybdänsul-fid, Fe203, red mud and combinations thereof. 3. The method according to claim 2, characterized in that the iron (III) oxide hydroxide catalyst y-FeO (OH) (gamma-FeO (OH)), a-FeO (OH) (alpha-FeO (OH)) or a Combination of it is. 4. The method according to any one of claims 1 to 3, characterized in that in the mixture, the catalyst in an amount of 0.1 to 20 wt .-%, preferably from 0.5 to 17 wt .-%, more preferably from 1 to 15 wt .-%, based on the total mixture. 5. The method according to any one of claims 1 to 4, characterized in that the black liquor is additionally mixed with sulfur or H2S. 6. The method according to claim 5, characterized in that in the mixture sulfur or H2S in an amount of 0.1 to 20 wt .-%, preferably from 0.5 to 15 wt .-%, based on the total mixture is included , 7. The method according to any one of claims 1 to 6, characterized in that the at least one hydrogen donor is selected from the group consisting of 1,2,3,4-tetra-hydronaphthalene (tetralin), formic acid, salts of formic acid, 4,5 Dihydropyrenes, 9,10-dihydrophenanthrene and combinations thereof. 8. The method according to claim 7, characterized in that recovered after liquefaction of the black liquor using 1,2,3,4-tetrahydronaphthalene as a hydrogen donor naphthalene from the mixture and rehy-driert to 1,2,3,4-tetrahydronaphthalene , For this 2 sheets of drawings