RU2041219C1 - Process for treating vegetable stock for preparing furfurol in alcohol-yeast production - Google Patents

Abstract

FIELD: hydrolysis production. SUBSTANCE: the process comprises sulfuric acid hydrolysis of at 170-195 C and a pressure of 8 to 12 atm. The stock includes (wt): 1.9-11.7 large (up to 30 mm) wood chips; 16-20.2 conditioned (up to 10 mm) wood chips; 9.9-12.9 bark; 62.2-65 rotten wood. The resulting hydrolysate is then evaporated, furfurol-containing vapours are condensed, the hydrolysate is fed for inversion by taking a sample of the furfurol-containing condensate, neutralization and cooling to obtain a furfurol-containing condensate which is directed for producing furfurol. The melt residue thus formed is fermented and directed for rectifying the alcohol. An alcohol amount of 5-25% of the resulting stream having a reducing agent concentration of 0.78-0.9% and an alcohol concentration of 0.05% is directed for wetting the starting material in combination with sulfuric acid and water. These operations enable one to increase the furfurol content in the hydrolysate to 0.04595-0.0607 ( by 1.5-2 times) and the RA concentration to 3.2-3.4% with the reduced amount of discharges and better utilization of wood waste such as bark and rotten wood. EFFECT: improved treatment process. 1 dwg

Description

 The invention relates to the hydrolysis industry, in particular to the development of methods for producing furfural, alcohol and fodder yeast using various types of plant materials.

 Furfural is obtained from furfural-containing condensates either as a result of furfural boiling of pentosan-containing raw materials at specialized furfural-profile plants, or as by-products in the production of ethyl alcohol and fodder yeast (Holkin).

 Under the conditions of thermocatalytic hydrolysis of plant materials with diluted sulfuric acid, part of the monosaccharides decomposes. Pentoses, which are formed mainly during the heating period and have the least stability compared to hexoses, disintegrate by 50-60% with the formation of furfural and other products before being removed from the apparatus. Approximately half of furfural contained in the hydrolyzate is separated with self-evaporation vapors on evaporators and about 35% of furfural remaining in the neutralizer is removed with condensate after vacuum cooling. The furfural content in the condensate of the self-evaporation vapors of the hydrolyzate and the neutralizer does not exceed 0.15-0.4%. The furfural yield depends on a number of factors, including the quality and particle size distribution of the raw material, the condition of its preparation, technological conditions aimed at the conversion of pentosans to furfural, taking into account the conservation of cellulose (EF Morozov. Production of furfural. M. Timber industry, p. 3, 1988).

The closest in technical essence is the known method for producing furfural in alcohol-yeast production, used, for example, at the Bobruisk hydrolysis plant (Morozov EF Production of furfural. M. Forest industry, 1988, p. 10). By this technology hydrolyzing hardwood trees at 170-195 ^{° C,} pressure 8-12 atm gidrolizapparate.

 The content of PB in the hydrolyzate was 2.36% acidity 0.45 / 0.32. The furfural content in the hydrolyzate is 0.038%. Furfural yield from cooking is 22.9 kg. The yield of fodder yeast from the total PB-63.4%. The objective of the invention is to develop a method for producing furfural in alcohol-yeast production, which allows to increase the yield of furfural without reducing the hydrolyzate PB and, accordingly, without reducing the yield of alcohol and fodder yeast.

 The developed technology will allow expanding the raw material base using wood processing waste, and reducing the volume and pollution of wastewater.

The problem is solved as follows. As hydrolyzable wood raw materials, take coniferous wood, wt. Large chips up to 30 mm 1.9-11.7
Wood chips up to 10 mm 16.2-20.2 Bark 9.0-12.9
Dust up to 5 mm (small fraction of wood) 62.2-65.0
Hydrolysis of the starting raw wood at a temperature of 170-195 ^C and pressure of 8-12 atm, the resulting hydrolyzate is fed to the evaporation, condensing furfurolsoderzhaschih vapor condensation and subsequent collection. Next, the hydrolyzate is directed to the inversion and selection of furfural-containing condensate in the inversion process. Then the hydrolyzate is fed to neutralization, clarification, cooling and selection of furfural-containing condensate.

 All of these furfural-containing condensates are collected and sent for rectification to obtain the target product of raw furfural.

 After clarification, the supply of nutritious salts, the prepared wort is sent to the fermentation department and then the brew for distillation to obtain ethyl alcohol.

After alcohol distillation vinasse in the amount of 5-25% of the total flow is directed to wetting the feedstock in a mixture with cooking acid, in order to obtain a 1% solution of H ₂ SO ₄ in an amount of 2.5 GM. The rest of the post-alcohol distillery stillage is used to produce fodder yeast.

Alcohol bard is characterized by the following indicators: total RV 0.70-0.90% alcohol content 0.005% A decrease in the amount of bard fed to the hydrolysis will result in a decrease in the yield of furfural from cooking, an increase in the amount of bard will degrade the quality of the hydrolyzate, which will require additional refinement. The output of the RS is influenced by the particle size distribution of the feedstock; therefore, the qualitative and quantitative composition of the hydrolyzable feedstock is selected in such a way as to provide a maximum yield of the RT of 3.2-3.4%. A decrease in the hydraulic module will result in the formation of a “caramel” residue in the apparatus. Thus, the novelty of the invention lies in the use of a certain qualitative and quantitative composition of raw materials, the use of post-alcohol distillery stillage for hydrolysis, the introduction of additional reception-selection of furfural-containing condensate in the process of inversion of the hydrolyzate. The main task in obtaining furfural in alcohol-yeast production is to create conditions under which an increase in the release of furfural from cooking does not lead to a decrease in the yield of RS. The present invention implements a method of processing coniferous wood using post-alcohol stillage in the process of hydrolysis. The content of furfural in the hydrolyzate is 0.06%, while the RV of the hydrolyzate is 3.2-3.4%
In the presence of post-alcohol bard, polysaccharides of coniferous wood can be completely hydrolyzed. Thus, the invention meets the criterion of "inventive step".

 The processing scheme of plant materials in accordance with the invention is shown in the drawing.

 The hydrolyzate from the hydrolysis apparatus 1 is fed to the evaporator 2, self-evaporation vapors are sent to a resofer 3, where a furfural-containing condensate (FSK) is formed, sent to the collection 4.

 The hydrolyzate is sent to the inverter 5, then to the gas cooling unit 6, and the resulting FGC in the collection 4.

 The hydrolyzate after the inverter 5 by pumps 9, to which neutralizing agents are supplied, is fed to the clarifier 10 for clarification, vacuum-cooling unit 11, from where the FGC enters the collection 4, after which, after distillation unit 7, the raw furfural product is obtained.

 After settling tank 10, supplying nutrient salts, the prepared wort is sent for fermentation to the fermentation unit 12 and to the distillation unit 13 to produce ethanol, and the post-alcohol stillage is divided into 2 streams, one of which is sent to the hydrolysis apparatus, and the other to the yeast compartment to obtain feed yeast.

PRI me R 1. In the reactor with a volume of 64 m ³ was loaded 9.3 tabs. dry raw materials of the following composition, Large chips up to 30 mm 1.9
Wood chips up to 10 mm 20.2 Bark 12.9 Dust 65.0
(fine fraction of wood up to 5 mm)
In the hydrolysis apparatus 1, 3.5 m ^{3 of} post-alcohol stillage, 180 l of H ₂ SO ₄ , 18.5 m ^{3 of} water are fed to wetting to obtain a 1% solution. The wetting hydraulic module is 2.5 GM. Warming up is carried out with hot steam for 50 minutes to a pressure of 8 atm. Then lead percolation hydrolysis at a temperature of 175-190 ^C and pressure rise up to 13 atm by feeding cooking acid 0,5% H ₂ SO ₄ in gidrolizapparat. The percolation process is carried out for 90 minutes. The resulting hydrolyzate is sent to the evaporators, where the evaporation process takes place, and therefore, the hydrolyzate is cooled to +110 ^о С. During the evaporation, the released furfural-containing vapors (FSP) are sent for condensation to the resellers 3, and the obtained FGC condensate enters the collector 4. From the evaporators 2 the hydrolyzate enters the inverter 5, where in 6-8 hours the process of decomposition of oligosaccharides to monosaccharides takes place, which is further utilized by yeast. The furfural vapors formed during the inversion are sent to gas cooler 6 and the obtained FGC enters the collector 4.

 The cooled and invertible hydrolyzate with the help of pumps 9 is fed to neutralization with milk of lime to a pH of 2.4-2.6 and ammonia water to a pH of 3.8-4.0. Next, the neutralize is clarified, in the sump 10, nutritious salts are added and the prepared wort is served for fermentation.

 The resulting mash is characterized by the following indicators: concentration, total RH content in the mash is 1.03% alcohol concentration is 1.40.

 In the process of rectification (node 13), ethanol is further obtained. The yield of alcohol with 100 kg of fermentable RS is 56.1 liters, the yield of alcohol with 100 kg of total RS is 34.3 liters. Furfural-containing condensate after resofer 3, from the vacuum cooling unit 11 and from the gas-cooling unit 6 through the collector 4 enters the distillation unit (main 7 and purification 8 columns) to obtain the target product of raw furfural. The output of furfural from cooking is 52.9 kg. The furfural content in the hydrolyzate is 0.0495.

 In the process of alcohol rectification, the resulting post-alcohol distillery distillate with an alcohol content of 0.005 and RV 0.79% is divided into 2 streams, 5% is fed to the wetting of raw materials, and the rest of the stream is sent to receive feed yeast.

The yeast yield from the total RV is 63.4%; the RV yield from 1 hour; 34.5% of the hydrolyzate RV
PRI me R 2. Analogously to example 1, hydrolysis of conifers of the following composition is carried out, large chips up to 30 mm 11.7
Wood chips up to 10 mm 16.2 Bark 9.9 Dust up to 5 mm 62.2
25% of the effluent of the post-alcohol stillage stillage containing 0.005% alcohol and 0.90% PB, i.e. 17.5 m ^{3 of} acid, 190 l of H ₂ SO ₄ , 4.5 m ^{3 of} water. Hydro-wetting module 2.5 GM. The following indicators are obtained: The content of total RV in the brew 1.03% The yield of furfural from cooking 60 kg The content of furfural in the hydrolyzate 0.0607 The yield of alcohol with 100 kg of fermentable RV 55.8 l The yield of alcohol with 100 kg of total RV 35.9 l Yeast yield from total RV 61.9% RV yield from 1 h 31.3% RV hydrolyzate 3.42
Thus, as a result of the developed technology, the content of furfural in the hydrolyzate increases by 1.5-2 times. The concentration of RS in the hydrolyzate rises to 3.2-3.4%

Claims (1)

METHOD FOR PROCESSING VEGETABLE RAW MATERIALS FOR PRODUCING FURFUROL IN THE ALCOHOL-YEAST PRODUCTION, including sulfuric acid hydrolysis of wood raw materials at a temperature of 170 195 ^° C and a pressure of 8 12 ati, evaporation of the obtained hydrolyzate, condensation of the hydrolyzate, and fururol inversion furfural-containing condensate, the direction of furfural-containing condensates to obtain furfural, obtaining wort with its subsequent fermentation, rectification of alcohol, directed e DDGS to feed yeast, characterized in that the wood raw material used softwood wt. Large chips up to 30 mm 1.9 11.7
Wood chips up to 10 mm 16.2 20.2
Bark 9.9 12.9
Junk 62.2 65.0
and additionally carry out the selection of furfural-containing condensate in the process of inversion, with 5 25% after alcohol stillage from the resulting stream with a concentration of PB 0.79 0.90% alcohol 0.005 sent to wetting the feedstock together with sulfuric acid and water with a wetting unit of 2.5 Hm.

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