Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
  • D21C3/00—Pulping cellulose-containing materials
  • D21C3/20—Pulping cellulose-containing materials with organic solvents or in solvent environment
• • C—CHEMISTRY; METALLURGY
  • C13—SUGAR INDUSTRY
  • C13K—SACCHARIDES OBTAINED FROM NATURAL SOURCES OR BY HYDROLYSIS OF NATURALLY OCCURRING DISACCHARIDES, OLIGOSACCHARIDES OR POLYSACCHARIDES
  • C13K1/00—Glucose; Glucose-containing syrups
  • C13K1/02—Glucose; Glucose-containing syrups obtained by saccharification of cellulosic materials

Definitions

• the invention relates to a process for the production of sugars from particulate cellulose material by treating the material in a pressure vessel with a mixture of acetone and water containing a small amount of an acidic compound at elevated temperatures.
• GB-A-416416 describes the recovery of cellulose by the extraction of lignin from a lignocellulose material with acetone or a mixture of acetone and water.
• acetone in volume concentrations in water of greater than 70% with a catalytic amount of an acid greatly accelerates the hydrolysis rates of cellulosic materials at elevated temperatures by sugar-acetone-complex formation.
• acetone complexes are found to hydrolyse roughly 500 times faster than the alkyl glucosides and polyglucan described in the prior art.
• Further benefit of the acetone-sugar-complexes is their facile separation into individual sugar species based on such simple processes as volatilization, selective hydrolysis and liquid-liquid extraction. Complex formation of monomeric sugars in anhydrous acetone in the presence of mineral acids at room temperature is described in Methods in Carbohydrate Chemistry, Vol. II, pp. 318.
• cellulosic material includes materials of vegetable and woody origin, i.e. cellulose and lignocellulose materials.
• reaction vessels with inert linings are used to eliminate the sugar degradation catalyzing effects of transition metal ions such as Ni, Co, Cr, Fe and Cu which may be components of metallic vessel walls, tubing and other control elements with which the hot liquor comes into contact.
• transition metal ions such as Ni, Co, Cr, Fe and Cu which may be components of metallic vessel walls, tubing and other control elements with which the hot liquor comes into contact.
• the temperature of the reaction mixture be rapidly lowered to under 100°C to avoid unwanted degradation of the sugars. This is best accomplished by controlled flashing-off of the volatiles since sugar degradation was found to be insignificant below the boiling point of water even in the presence of dilute acids.
• the cooling of the liquor can be continued to ambient temperatures or less (25°C) before fermentation or further processing.
• the liquor-to-wood ratio can be kept constant at 10:1 as by necessity successive additions both wood and liquor will carry hydrolyzates of the residuals already within the reactor.
• This also establishes sugar concentrations to' be in the order of 37 to 40% following flash evaporation of the volatiles.
• Such high sugar solids concentrations were hitherto possible only with strong acid hydrolysis systems but not with dilute acid hydrolysis.
• liquor to wood ratio is extremely important in organosolv and acid hydrolysis processes since it directly relates to energy inputs during the hydrolysis and solvent recovery as well as during alcohol recovery from the resulting aqueous solution following fermentation of the sugars to ethanol or other organic solvents.
• liquor to wood ratio will have a profound effect on the economics of biomass conversion to liquid chemicals as well as the energy efficiency (energy gained over energy expanded in conversion) of the process.
• Saccharification power and sugar survival were compared for three competitive systems namely: acidified water (aqueous weak acid), acidified aqueous ethanol and acidified aqueous acetone in the following example.
• the combined filtrates were diluted to 100 ml with water and a half milliliter aliquot was placed in a test tube with 3 ml of 2.0 Normal sulfuric acid added and subjected to a secondary hydrolysis at 100°C by heating in a boiling water bath for 40 minutes.
• the solution was neutralized on cooling and the sugars present in the solution were determined by their reducing power.
• the results were thus uniform based essentially on the resultant monosaccharides liberated during the hydrolysis process.
• Theoretical percentage of reducing sugars available after the hydrolysis of the substrate was determined by difference between the known chemical composition of the starting material and the weight loss incurred due to the hydrolysis.
• Solid residues less than 50% in yield show high degree of crystallinity (87%) and are pure white, have a DP (degree of polymerization) of 130 to 350.
• the invention allows facile segregation and nearly quantitative isolation of the five major wood sugars, if so desired.
• the mixed nature of the sugar derivatives in aqueous hydrolyzates if such thorough and detailed separation is desired, it is always necessary to neutralize the recovered aqueous sugar wort after removal of the volatiles and concentrate the wort to a syrup.
• the syrup is then redissolved in anhydrous acetone containing 3 percent acid, allowed to stand at least 6 hr until all sugars formed their respective di-acetone complexes before attempting the detailed separation as described below.
• the separated sugar complexes are readily hydrolyzed in dilute acid on boiling at least 20 to 40 minutes.
• the combined filtrate (127 ml) was neutralized and subjected to steam distillation in an all glass apparatus and approximately 35 ml distillate was collected. Both the distillate and residual solution were made up to 100 ml and 0.5 ml portions of each were acidified with sulfuric acid to 3 percent acid and boiled for 40 min on a water bath. The solutions were neutralized and the sugar reducing power determined by the Somogyi method. The yield of sugars was 1.89 g in the distillate and 1.96 g from the residual liquor.
• Hydrolysate No. 3 contained only traces of lignin after evaporation of the acetone solvent too small to collect and determine gravimetrically. It was removed by centrifuging. The aqueous residue (97 ml) was acidified to 3 percent acid with sulfuric acid, boiled for 40 min and after neutralization filtered and made up to 100 ml. The reducing sugar content of the filtrate was determined by the Somogyi method to be 1.83 g. GC analysis of the alditol acetates determined on an aliquot sample indicated mainly glucose with traces of mannose and galactose.
• Hydrolysate No. 4 and 5 were processed and analyzed in the same manner as No. 3. H-4 yielded 1.73 g reducing sugars and H-5 yielded 1.40 g sugars both being composed only of glucose as evidenced by GC analysis of an aliquot sample.
• Example VI In a similar hydrolysis arrangement to Example VI 10 g OD Douglas-fir sawdust (to pass a 10 mesh screen), pre-extracted with dichloromethane and air dried to 8 percent moisture content in a controlled humidity room, was hydrolyzed with 80:20 acetone:water solvent containing 0.05 Normal Hydrochloric acid in five consecutive steps. Each reaction step consisted of three minutes at a reaction temperature of 200°C. The heating up time was 7 minutes. Again Hydrolysate No. 1 and 2 were combined whereas the subsequent fractions were analyzed separately.
• the combined liquor of H-1 and H-2 yielded 2.39 g lignin on low temperature evaporation of the volatiles and 135 ml of aqueous liquor was collected on filtration of the powdered lignin.
• the dried lignin had a weight average molecular weight of 3200.
• the filtrate was neutralized to pH 8 and subjected to steam distillation in all glass apparatus.
• the 28 ml distillate which was collected contained 0.62 g pentoses which after passing the filtrate through a cation exchange resin in the acid form and repeated steam distillation of the filtrate yielded 0.58 g xylose as determined by GC analysis.
• the ethanol-petroleum ether solution was extracted with 5 ml portions of water and the collected aqueous layer combined with the syrup removed from the crystalline product above.
• the solution was briefly heated to expel the alcohol, made up to 3 percent acid with hydrochloric acid, boiled for 40 min, neutralized with silver carbonate and alditol acetates were prepared for GC analysis.
• the combined syrup and filtrate contained a total of 58 g sugars of which 0.29 g was galactose, 0.25 g was glucose and 0.04 g was mannose.
• Hydrolysate No. 4 gave 1.66 g of pure glucose with only very small traces of lignin, whereas H-5 gave 1.85 g of glucose and no lignin. The undissolved residue was 0.18 g and was composed of 99 percent glucose.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Emergency Medicine (AREA)
• General Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Biochemistry (AREA)
• Organic Chemistry (AREA)
• Saccharide Compounds (AREA)
• Preparation Of Compounds By Using Micro-Organisms (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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• 1982
  • 1982-03-23 AR AR28884882A patent/AR227462A1/es active
  • 1982-03-26 DE DE8282900956T patent/DE3274120D1/de not_active Expired
  • 1982-03-26 EP EP19820900956 patent/EP0074983B1/en not_active Expired
  • 1982-03-26 JP JP57501134A patent/JPH0785720B2/ja not_active Expired - Lifetime
  • 1982-03-26 WO PCT/EP1982/000068 patent/WO1982003409A1/en active IP Right Grant
  • 1982-03-26 BR BR8207243A patent/BR8207243A/pt not_active IP Right Cessation

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