CS271533B1 - Method of 2-furfuraldehyde and cellulose production fro, lignocellulosic raw materials - Google Patents

Abstract

The solution involves the processing of lignin-cellulose raw materials with a higher content of pentosans, for example, many broadleaved species like beech, beech bark and agricultural waste like corn cobs and trash, straw, fruit trees and vineyards pruning trash. The principle of the solution consists in the fact that in the first step the lignin-cellulose material with 10-60% of water is treated by tri-hydrogen phosphoric acid (1-10% of the overall weight) relative to the weight of the material dry matter at temperatures of 135 - 175 degrees C for 40 - 90 min and in the second step the lignin-cellulose leftover is delignified at atmospheric pressure by deconcentrated acid with an oxidizing effect, like nitric acid or peracetic acid in a concentration of 1-10% of the overall weight at a temperature from 60 degrees C to the solutions boiling point temperature for 30 to 120 minutes and neutralized by appropriate potassium hydroxide or ammonium hydroxide solution in a concentration of 1-10% of the overall weight.

Description

The present invention relates to a process for producing 2-furaldehyde and pulp from lignin cellulosic raw materials having a higher pentosan content than e.g. several deciduous trees and especially beech, beech pound and polhohoapodárake wastes such as corn cobs and sticks, straw, wastes from fruit etron and vine pruning ·

In the production of 2-furaldehyde from lignin cellulose raw materials, the catalytic effect of sulfuric acid is most often used. In AO 225851, the protected process for the treatment of said raw materials is 1.5 to 3% H ₂ SO ₄ at boiling point, resp. 0.75 to 1% ^H ₂ ^SO 4 ^{at a temperature of up to 135} ° ^C · ^{This treatment} yielded a first hydrolyzate suitable for the production of 2-furaldehyde and relatively little degraded partially hydrolyzed wood from which, after delignification and neutralization, it was obtained pulp · AO 235710 protects a process for the production of fibrous mass from such hydrolysed wood, even suitable for the production of fiber boards · USSR 151 683 ea proposes a process for the production of 2-furaldehyde after application of concentrated sulfuric acid to the surface of the feedstock at temperatures of 130 ° C to 130 ° C. It states that these production conditions retain intact cellulose in the lignin cellulose residue. In AO 229440 ea and for the aforementioned purposes, and in view of minimizing the degradation of the lignin-cellulose residue, consider more gentle processes with trihydrogen phosphoric acid.

A disadvantage of the two-stage epoeobic production of 2-furaldehyde according to АО 225851 and АО 229440 is the more complicated production and extracts of 2-furaldehyde, but the msnsj degraded lignin cellulose residue (partially hydrolysed wood) is obtained. considerable degradation of the lignin cellulose residue caused by strong mineral acid despite gentle production conditions · The residual lignin cellulose obtained by this process is in practice only used for hexosan hydrolysis. Higher degradation of residual lignin cellulose has also been demonstrated in our testing quarter-operation experiments under the conditions of the above patent. · Another disadvantage of sulfuric acid processes is the high corrosion rate, especially when working at elevated temperatures.

The above-mentioned disadvantages of the processes for producing 2-furaldehyde and pulp from lignin cellulose raw materials are eliminated in the process according to the invention, which is based on the fact that in the first step lignin cellulose raw material with a content of 10 to 60 wt. water is treated with 1 to 10% by weight of phosphoric acid, based on the dry weight of the raw material at 135 to 175 ° C for 40 to 90 minutes, and in the second stage the lignin cellulose residue is delignified under atmospheric pressure with an acid with oxidizing effects such as peracetic at a concentration of 1 to 10% by weight at a temperature of from 60 ° C to the boiling point of the solution for 30 to 120 minutes and neutralized with an aqueous solution of potassium or ammonium hydroxide at a concentration of 1 to 10% hmbt · Beech wood, beech cart, forest chips from woody wood or sorted waste from forest or technological chips, corn cob and straw, eventually straw. lignin cellulose at a concentration of 15 to 40% by weight · and then in the autoclave is blown through with steam at 135 to 175 ° C, most preferably 145 to 160 ° C for 40 to 90 minutes depending on the system used · For continuous production, more intensive conditions are preferable in shorter times and discontinuously vice versa it is emptied from the autoclave under elevated pressure to disintegrate it, preferably 0.5 to 3 mm in size and in this form it is delignified to pulp for chemical or feed industry purposes. in concentrations of 1 to 10% at temperatures from 60 ° C to the boiling point of the solution at a time of 30 to 120 sin. The optimum delignification conditions should be chosen mainly depending on the feedstock, the degree of degradation, the degree of disintegration and the moisture content of the residual lignin cellulose, as well as the purpose of the pulp. After the oxidation step, the oxidized components, in particular lignin, are dissolved and removed with dilute alkali solutions. The leachate obtained can be applied in agriculture as fertilizers.

CS 271533 Bl

The advantage of the proposed process over the prior art is that, in comparable yields of 2-furaldehyde, the residual lignin cellulose is degraded. up to 500 «The pulp produced in this way is suitable for cheaper and slurry treatment · Substantially reduces the corrosion of the 2-furaldehyde plant and obtains a suitable by-product - fertilizer ·

The subject matter of the invention is illustrated on 7 examples of embodiment · without affecting the body ·

Example 1 * In 32/2 kg of the wet chips of beech / the dry weight amounts to 20 kg / collected from one plant to produce fiber doaák loaded with 940 g of 85% ^{н з ГО} 4 ^ t »J · 4% of the dry weight of wood kyaeliny · e and Potoя the chips were poured into a heated vertical autoclave with a diameter of 35 ce and a height of 130 cc. · The autoclave was equipped with a stirrer, a steam inlet via a control valve in the epoxy part of the autoclave, and a condensate drain. Powerful cable cooler caz filter · Temperature and pressure sensors are integrated in the autoclave · Saturated water vapor at 165 ♦ 5 ° C has been fed into the autoclave from a sweeping lip dispenser with an automatic temperature control. o create a drain valve and trap condensed vapors · Sampling was regulated at a rate of 4 ♦ 0.5 1 per 10 ain / in each sampled fraction determined the concentration of 2-furaldehyde spectrophotonetrics in the UV and organic acids titration to phenolphthalein · Total collection time was 90 ain · After this time the seals were closed with water vapor gasses were still captured and also analyzed · After partial cooling of the autoclave for half an hour, they removed residual lignin cellulose · We achieved these results in terms of the dry weight of the raw material)

2-Furaldehyde yield 7.93% Organic acid yield (calculated on acetic acid) 3.56% Residue on wood grain / approximate / 21.80% Pentosate content in residual lignin cellulose 4.90%

Example 2

To compare the degradation effects of the individual catalysts, the effect of H ₂ SO ₄ was tested in the same manner as in Example 1. · For the same amount of beech chips, eme пап1ев11 714 g 70% H ₂ SO ₄ ; ie · 2/5% dry acid wood acid · Temperature lowered to 155 * 5 ° C

2-Furaldehyde Yield 6.98% Yield of Organic Acids like Acetic Acid / 4.72% Wood Loss 25/20% Pentosate Content in Residual Lignin Cellulose 4.93%

Example 3

Beech cart and approx. 17% wood and ea loose and grind to fraction predominantly 1 to 7 nm · 6.7 kg 15% ^H 3 ^TO 4 * ^t · ^ was applied to 21 / 7.kg air-dry cart (20 kg dry matter) · ⁵ acids per dry matter · Reaction temperature 170 ° C. Same procedure as in example 1 ·

CS 271533 Bl

Extract of 2-furaldehyde

Yield of organic acids (such as acetic acid) Decrease in weight of diamond

Obeah pantosans in residual lignin cellulose

4,55%

1; 73%

1ДЗ%

Example 4

For 16/5 kg of air-dried corn pulp / ground maize horns on a MK 1 hammer-mill for a particle size of predominantly 2 to 10 mm / o dry matter 91%, i.e. 15 kg of absolute dry weight, 2.2 l of water was applied. hours 0.706 kg 85% H 2 PO 4 / t, J · 4% acid on dry matter · Potoa as in Example 1 at 160-165 ° C obtained the following results:

2-Furaldehyde yield 10.60% Organic acid yield 3/87% Maot haatnoate loss 23/70% Pantosans content in residual lignin cellulose 9.10%

Under the same conditions in the comparison test and sulfuric acid, an unusable residue has already been produced for pulp production.

EXAMPLE 5 kg of residual lignin cellulose of Example 3 and poured 200 [mu] l of 9% peracetic acid prepared in the paste and left to soak at 90 [deg.] C. in 1 h. After filtering and washing with hot water to remove hydrogen peroxide, nearly 20% of pulp was calculated. ·

Example 6

Per 100 g of dry matter of the lignin cellulose residue from Example 1, ground to a fraction to mm e, 700 [mu] l of 5% HNO4 / was heated to boiling and boiled for 1 h. Potoa aa solution was poured and the remainder preayl 1 L of water, K residue aa added 1% KOH at both 1 and 10 hydroaodule and heated to 80 ° C · Dissolved lignin ea was filtered off and pulp ea was further washed with water until debris was removed. pulp ·

Example 7

Following the procedure of Example 5, 32% pulp was obtained from the lignin cellulose residue of Example 4.

Due to the neutralization, the digestion oxides are mixed together with the acid treatment and the alkaline solution. The extracts, if necessary, are used as a fertilizer in agriculture. The rinse water can be used in the preparation of the solutions or added to the leachate.

Claims (1)

CS 271533 B1 4.55% 1/73% 26/8% 1/13% 2-furaldehyde yield Organic acid yield / as kye. acetic acid / Habitat not weight of barley Pentose content in residual lignin cellulose Example 4 16,5 kg of air-dry maize pulp / ground maize chips on hammer mill MK 1 for particle size prevalent from 2 to 10 mm / 91% dry matter, t.J. 15 kg of dry weight was applied to 2.2 l of water after 3 hours 0.706 kg of 85% H-PO ^, t.J. 4% acid to crushed solids * The following results were obtained as in Example 1 at 160-165 ° C: 2-furaldehyde yield 10.60% Organic acid yield 3/87% Maize 23%; pentosans in residual lignin cellulose 9.10% Under the same conditions, a comparative test with sulfuric acid has already produced an unusable residue of pulp production. Example 5 5 kg of milled residual ligninulose of Example 3 was poured into 200 ml of 9% peracetic acid prepared and left to stand at 90 ° C for 1 hour. After filtering with hot water to remove hydrogen peroxide, almost 20% of the pulps were converted into residual lignin cellulose. Example 6 To 100 g of dry matter of the lignin-cellulose residue of Example 1, milled to a fraction of 5 mm, 700 ml of 5% ΗΝθ3 'heated to boiling was added and left to boil for 1 h. The solution was then poured off and the residue washed with 1 L of water. 1% KOH was added with hydromodule 1 and 10a and heated to 80 ° C. The dissolved lignin was filtered off and the pulp was thoroughly washed with water to remove the liquor. 46 g of pulp dry matter was obtained. EXAMPLE 7 Example 5a and the lignin-cellulose residue of Example 4 obtained 32% of the pulp. Nitrogen oxides are neutralized by leaching after acidification and heat treatment. Leaches after optional pH adjustment are used as fertilizers in agriculture. Water washings can be used to prepare solutions or add to leaches. EXAMPLES A method for producing 2-furaldehyde and lignin-cellulose pulp, characterized in that in the first step, a lignin-cellulose feedstock containing 10 to 60% by weight of water-based trihydrogenphosphoric acid is present in an amount of 1 to 10% by weight relative to the weight of the dry matter. raw material at 135-175 ° C for 40-90 min, and in the second stage, the lignin-cellulose residue is dalignifiltrated at atmospheric pressure diluted with acid with oxidizing agents such as nitric acid or peracetic acid at a concentration of 1 to 10% by weight. at a temperature of from 60 ° C to the boiling point of the solution 30 to 120 minutes and neutralized with an aqueous solution of potassium hydroxide or ammonium hydroxide at a concentration of 1 to 10% by weight.