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
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23K—FODDER
  • A23K20/00—Accessory food factors for animal feeding-stuffs
  • A23K20/10—Organic substances
  • A23K20/142—Amino acids; Derivatives thereof
  • A23K20/147—Polymeric derivatives, e.g. peptides or proteins
• • 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
• • 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
  • C13K1/06—Glucose; Glucose-containing syrups obtained by saccharification of starch or raw materials containing starch
• • 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
  • D21C11/00—Regeneration of pulp liquors or effluent waste waters
  • D21C11/0007—Recovery of by-products, i.e. compounds other than those necessary for pulping, for multiple uses or not otherwise provided for

Definitions

• organsolv dissolution by hydrolysis processes have been successfully demonstrated on certain types of cellulosic materials, particularly lignocellulosics.
• the easiest wood to delignify by organosolv solutions is aspen, while conifers such as spruce and pines and especially hemlock ( Tsuga hetr ⁇ phyl la ) showed substantial resistance.
• Sugarcane rind was found to be relatively easy to hydrolyse.
• Cotton linters which are essentially pure cellulose, especially the crystalline fraction, were very difficult to hydrolyse by prior art processes.
• organosolv processes have been demonstrated with cellulosic materials which are easy to delignify. Conifers thus have been largely avoided because of their resistance to hydrolysis and the harsher conditions required for their rapid conversion to monomeric products.
• organosolv processes for delignification and/or saccharification of cellulosic materials and stalks of vegetable crops.
• organosolv processes involve the use of a mixture of water and a solvent such as alcohols and ketones and sometimes other solvents of a specific or non-polar nature along with an acidic compound to facilitate the hydrolysis.
• solvent such as alcohols and ketones
• 2,022,654 also to Dreyfus (1935) describes a similar approach for the production of cellulose pulp in that wood chips are pre-treated with concentrated acid carried in up to 80 per cent acetone in water to soften the wood and after substantially removing all the acid, the chips were digested for 9 to 12 h at 170°C to 230°C in a pressure vessel using 50 to 80 per cent acetone water mixtures and a non-polar organic solvent.
• US P No. 2,959,500 to Schlapfer et al describes a hydrolysis process with the solvent consisting of selected alcohols and water and optionally a non-polar solvent at 120°C to 200°C in the presence of small amounts of acidic compounds which were claimed to be non-reactive with the alcohols selected for the process.
• D 21 C 3 to Paszner et al deascribes treatment of lignocellulosics in a single step with acidified aqueous acetone solution of up to 70 per cent organic solvent content and claims rapid total dissolution of all types of woods.
• the sugar yields amounted to 65 to 72 per cent depending on the wood species.
• the main object of the present invention is to rapidly and quantitatively solubilize and recover the chemical components of lignocellulosic and strach containing materials.
• a further object of theinvention is to reduce the hydrolysis time and substantially increase the sugar formation rates.
• a further object of the invention is to reduce the degradation of the sugars to non-sugars during the high temperature hydrolysis process in the presence of acids.
• a further object of the present invention is to simultaneously dissolve and then recover separately the chemical constituents of lignocellulosic and strach containing materials to yield mainly pentose and hexose sugars, lignin and protein rich products if the materials is a cerial or starchy tuber.
• a further object of the present invention is to conduct the hydrolysis in such a way that when the organic volatiles are removed from the hydrolysis liquor, and the lignin or protein residue is separated from the residual solution, higher than 10 per cent by weight of sugar solids is obtainable by the process.
• a further object of the invention is to substantially reduce the concentration of acid required to maintain and regulate a given hydrolysis rate and thereby substantially reduce the catalytic effects of acids in degradation of the dissolved sugars at high temperature.
• the object of the present invention is to reduce the reaction temperature required to achieve a certain reaction rate during the hydrolysis process and thereby maximize the sugar recovery.
• a further object of the present invention is to reduce the energy required for the hydrolysis by use of the low boiling solvent which has heat capacity and vaporization values substantially lower than known for water.
• a further object of the invention is to obtain high purity low DP cellulose on hydrolysis of cellulosic materials, and protein residues on hydrolysis of strachy grains and tubers which could serve as animal fodder, food additive and as industrial filler and adsorbent.
• the present invention relates to an improvement in a process for the production of crabohydrate hydrolysates as sugars from a comminuted cellulosic material which can contain lignin by treating the material in a pressure vessel with a solvent mixture of acetone and water containing a small amount of an acidic compound at elevated temperature to form reducing sugars in a liquor, the improvement of which coprises: a. providing mixtures of acetone and water containing at least about 70 volume precent of acetone and the catalytic acid compound as the solvent mixture in the pressure vessel at elevated temperatures with the material to be hydrolysed; b.
• the present invention also relates to improvements in a process for the production of carbohydrate hydrolysates as sugars, lignin or protein form comminuted lignocellulosic or starch containing materials by treating the materials in a pressure vessel with a solvent mixture of acetone and water containing a small amount of an acidic compound at elevated temperatures to solubilize any lignin and to form reducing sugars in a liquor and to recover a high protein content residue which comprises: a. providing mixtures of acetone and water containing at least 70 percent acetone and the catalytic acidic compound as the solvent mixture in the pressure vessel at the elevated temperatures with the material to be hydrolysed; b.
• the surprising result of the present invention is that even at significantly reduced acid concentrations the rate of carbohydrate hydrolysis is several ordersof magnitude higher than in water under identical conditions and that substantially no degradation of the sugars takes place during the high temperature hydrolysis process although actone complexes of the sugars are known to undergo hydrolysis themselves some 100 times faster in aqueous acidic solutions than alkyl glucosides or the polyglucan itself.
• the accelerated hydrolysis rate of the main decomposition is found to provide the opportunity to substantially reduce the amount of solvent required earlier to achieve a certain degree of dissolution and sugar recovery:
• the lower substrate to solvent ratio materailly lowers the energy requirement for the process.
• a further benefit to the process acrues from the advantageous physical and chemical properties of the complexes themselves. It is for instance known that sugar-acetone complexes have different volatility at high temperature depending on the sugar species. Thereby the vapour pressure of the pentodes is much higher than that of the hexoses whereby the pentoses can be made volatile under certain conditions. Further the various sugar complexes show also differential sensitivity to weak acid hydrolysis or hydrolysis on ion exchange resins. Whereas the sugar-solvent complexes are soluble in non-polar organic solvents those of the free sugars are not. Thereby it is possible to separate the individual sugar species based on selective hydrolysis sensitivity and solubility in selected solvents.
• cellulosic material includes materials of vegetable and woody origin which may or may not be lignified, generally in comminuted form.
• starchy materials includes cerial grains and tubers of vegetable origin, which may or may not be mixed with cellulosic above ground biomass or protein, generally in comminuted form.
• the acidic compound can be of inorganic or organic origin and should be inert with respect the solvent. Strong acids such as sulphuric, hydrochloric and phosphoric acids are preferred; acidic salts such as aluminium chloride, sulphate, ferric chloride and organic acids such as trifluoroacetic caid can also be used.
• the elevated temperatures are between 145oC to 230°C and most preferably between 155°C to 210°C.
• the catalytic amount of acidic compound is preferably between 0.025 to 0.5 weight per cent of the solvent used. Smaller amounts are also effective especially when higher temperatures are selected.
• a reaction time, for treatment of less than required to dissolve 50 to 70 per cent of the solid residue at the particular acid concentration and reaction temperature should be used and allows high yield of reducing sugars in the monomeric form.
• the sugar exposure time to high temperature will generally regulate the solvent feeding rate to the reactor and will generally depend on the acetone concentration, acid concentration and the temperature used.
• the acid concentration should be about 0.04 to 0.06 Normal, acetone concentration about 80 per cent and the temperature over 200°C.
• low acid concentration (0.02 Normal and less), high acetone concentration (above 80 per cent) and high temperature (above 200°C) are most suitable.
• the prior art weak acid and alcoholic organosolv processes are relatively slow and have had limited hydrolysis power even with relatively easily hydrolysable materials such as poplars and sugarcane rind (bagasse).
• the lignin is resinified to a dark refractory mass.
• the sugar yields rarely exceed 60% of the theoretical value by such processing.
• higher sugar yields were said to occure with enzymatic hydrolysis, the process is very slow and expensive.
• the lignin usually remains contaminated with sugar residues.
• Starchy materials such as cerial grains are traditionally treated mechanically to separate the verious fractions such as the germ, cellulose, starch and protein for further processing and use. In fermentation to alcohol only the starch sugars are utilized. To facilitate the use of the starch it first has to be hydrolysed by combined action of acid and enzymes. The cellulose and protein residue is usually marketed separately. Thus the process is cumbersome and yields less than the theoretically available carbohydrate in the grain as it is incapable of also hydrolysing the nearly 20 to 30 carbohydrates in the form of cellulose and pectic substances (hemicelluloses. Thus ethanol production from grain usually does not involve the hulls and seed shells. Processes for isolation and hydrolysis of straches are described by Radley in Stach Production Technology (1967) .
• the total biomass produced including the above ground growth (vegetable stems) and below ground tubers, can be as high as 200 T/ha as is the case with Jerusalem artichoke and cassava or manioc (la tropha manihot and its other vaieties) grown around the Tropic of Cancer around the world.
• the starch content was of industrial interest by extracting the starch granules from finely comminuted tuber pulp with water. The process is very water and energy intensive.
• their use for fermentation to alcohol must be preceeded by a combined enzyme/acid hydrolysis of the starch to monomeric sugars.
• the residual pulp contains 10 to 15 per cent cellulose and about equal quantities of proteins. In the manufacturing of starch presently the cellulose is sold together with the protein as cattle feed.
• the protein network which normally encapsulates the starch grains remains uridissolved as a spongy light brown residue which could be easily filtered off (it retained the shape of the tuber particles processed through the reactor) and the entrapped sugar solution removed by squeezing or centrifuging. Upon removal of the organic component of the solvent a small quantity of drak brown precipitate is formed. This precipitate together with the color of the aqueous residue is easily removed by treatment with charcoal or filtration through a charcoal bed to obtain crystal clear sugar solutions. When the acid strength of the solution is increased to 1.5 per cent and the solution is boiled for 20 min. the cooled solution contains the free sugars in a fermentable form.
• Reaction vessels with inert linings are used to eliminate the sugar degradation catalysing effects of transition metal ions such as Ni, Co, Cr, Fe, and especially Cu which may be components of metal vessel walls, tubing, heat exchangers and present in spring waters.
• transition metal ions such as Ni, Co, Cr, Fe, and especially Cu which may be components of metal vessel walls, tubing, heat exchangers and present in spring waters.
• the recovery of pentoses from the reaction mixture is generally by flash evaporation of the major fraction of the acetone first with continued distillation under reduced pressure, or by steam stripping, or by liquid-liquid extraction. Vacuum distillation and steam stripping can under suitable conditions result in the separation of the pentose sugar complexes form the solution. Separation of the pentose, hexose sugar complexes is made possible by the largely different boiling points of their acetone complexe which apparently form even in the presence of smamll amounts of water during the high temeperature hydrolysis step in the present invention provided the acetone concentration is higher than 70 volume per cent.
• the lignin precipitates as water insoluble relatively low molecular weight (M - 3 200 - 1 800) granular powder having spherical particle sizes between 2 to 300 micrometers on filtration and centrifuging.
• Purification of the crude lignin is by repeated re-dissolution in acetone, filtration to remove undissolved residues and re-precipitation into large excess of water or by spray drying the highly concentrated acetone solution.
• the remaining aqueous solution after filtering off the lignin precipitate can be purified on filtering through a charcoal bed and will contain mainly hexose sugars of 10 per cent and greater concentration.
• the temperature of the reaction mixture be rapidly lowered to under 100oC 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. Usually the cooling can be continued to ambient temperatures or less before fermentation or further processing. If the sugar complexes are to be preserved rapid neutralization of the solution with bicarbonate will stabilize the complex.
• the above described process can be operated in a continuous or semicontinuous manner using batch cooking principles for the latter.
• Semi-continuous saccharification would employ a battery of pressure vessels each at various stage of hydrolysis to simulate a continuous process.
• all stages of hydrolysis are accomplished in a single pressure vessel and the product mix is always determined by the particular saccharification program set.
• Comminuted solids and the hydrolysis liquor are fed continuously to the pressure vessel at such a rate that the time elapsed between feeding and exit of the products would not exceed that determined earlier to obtain 50 to 70 per cent hydrolysis of the solid residue present at any time in the pressure vessel.
• the residence time of the hydrolysis liquor would be always fitted to the most sensitive stage in order to provide sugar recoveries exceeding 90 to 95 per cent for that particular stage.
• lignocellulosics the three major stages of saccharification to be considered are: a. bulk delignification and pre-hydrolysis ; during this stage up to 75 per cent of the lignin and 95 per cent of the governing hemicelluloses (xylose in hardwoods and mannose in softwoods) may be reomved.
• the solid residue yield is invariably above 50 per cent of the starting material; b. continued delignification and cellulose purification stage; during this stage delignification is largely completed and the rest of the hemicellulose sugars and some of the amorphous glucan are removed.
• the solid residue at this stage is generally less than 35 per cent and is predominantly crystalline in nature; c.
• stage b. the residual cellulose of stage b. is decomposed to monomeric sugars. This step may take more than one liquor change to accomplish a better than 90 per cent sugar recovery. Such stages of dissolution could not be identified for the starchy materials since the hydrolysis of cellulose and starch appears to be simultaneous and extremely rapid due to the good accessibility.
• liquors collected from the various stages of hydrolysis may contain sugars from all stages a. to c. which is the situation with an apparatus having no means of separating the top pre-hydrolysis liquor from the rest of the liquor pumped in with the chips.
• Such separation for purifictaion of the sugars is unnecessary because the sugars occur as complexes, the pentoses having different volatility than the hexoses with which they may be mixed.
• the lignin is separated on basis of its insolubility in water and is recovered outside the reactor on flash evaporation of the organic volatiles. Gluten and protein from cerial grain and tuber processing are separated as solid residues following the hydrolysis stage.
• first and second stage liquors Separation of the first and second stage liquors would have particular significance on continued heating of these sugars to cause dehydration of especially the pentoses to produce corresponding furfurals and levulinic acid. In this case only minor amounts of hexose sugars would have to be hydrolysed.
• the sensible way to produce furfural from pentoses is following the flash evaporation stage which includes steam stripping which separates the sugar complexes according to their volatility. Such distillates when acidified can be reheated under highly controlled conditions and high purity furfural produced in better than 75 per cent yields.
• the preferred liquor to wood ratio is 5:1 to 10:1 with densified materials liquor to wood ratios as low as 3:1 may be achieved. Due to the shrinking mass bed the total amount of liquor required for hydrolysis of 100 kg aspen poplar at constant liquor to wood ratio of 7:1 is 1 356 kg for an overall liquor to wood ratio of 13.56:1. Under these conditions the average sugar concentration in the combined residual aqueous phase (271 kg) is 30 per cent (82.3 kg of recovered sugars) .
• the liquor to wood ratio can be kept constant at 10:1 as by necessity successive additions of both wood and liquor will carry hydrolysates of the residuals already within the reactor.
• This also establishes sugar concentrations to be in the order of 37 to 40 per cent following flash evaporation of the volatiles.
• Such high sugar 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 mash following fermentation of the sugars to ethanol or other organic solvents.
• the 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 rates were compared for three competetive 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 0.5 ml aliquot was placed in a test tube with 3 ml of 2.0 Normal sulphuric acid and subjected to secondary hydrolysis at 100°C by heating in a-boiling waterbath for 40 min.
• 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 on the the resultant monosaccharides liberated during the hydrolysis process.
• the theoretical percentage of reducing sugars available after 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.
• the increased sugar survival with increase in acetone concentration is attributed to formation of acetonesugar complexes which have improved stability at high temperature.
• the complexes are very readily and safely hydrolysable to free sugars on heating with dilute acid at 100oC for a limited amount of time.
• Solid residues less than 50% in yield show a high degree of crystallinity (87%) and are pure white, have a DP (Degree of Polymerization) of 130 to 350 glucose units.
• the rate of sugar degradation can be offset somewhat by lowering the acid concentration and increasing the liquor-to-wood ratio, whereby the forward reaction rate (k 1 ) in hydrolysis remains unaffected but the sugar degradation rate (k 2 ) is lowered sub stantially.
• sugar survival which depends on the ratio of k 1 /k 2 is largely improved especially if high, acetone concentrations are used.
• Such manipulations of the temperature acid concentration parameters are not possible with the weak acid aqueous systems.
• Douglas-fir hydrolysis was somewhat slower than that of aspen and sugarcane rind (bagasse) .
• a hydrolysis rate of 0.5 x 10 3 min -1 was obtained and only 6 per cent loss was recorded for a 280 min long cook at 180oC the usual dilute acid hydrolysis temperature.
• the high acetone content hydrolysis liquor allowed at least 100.times faster hydrolysis of Douglas fir by simultaneous dissolution of the lignin than possible in purely aqueous systems.
• solid residues of about 30 to 35 per cent yield are pure white cellulose, totally devoid of residual lignin.
• the cellulosic fraction has a crystallinity index of 80 per cent from aspen wood and a degree of polymerization of between 80 to 280. Similar results are obtained with other wood species.
• the inevntion also allows facile separation and nearly quantitative isolation of the major sugars, if so desired.
• the syrup is then re-dissolved in anhydrous acetone, acidified to 3 per cent with mineral acid, and allowed to stand from 4 to 6 hr until all sugars fully formed their respective di-acetone compexes. Neutralization will allow recovery of the sugar complexes in a stable state suitable for separation as described in the next example.
• the separated sugars are then readily hydrolysed either selectively on ion exchange resins or in bulk by boiling at least for 20 min in acidified water.
• the combined filtrates (127 ml) were neutralized and subjected to steam distillation in an all glass apparatus and approximately 35 to 40 ml distillate was collected. Both the distillate and residual solution were made up to 100 ml and 0.5 ml portions were acidified to 3 per cent acid and boiled for 40 min on a water bath. The solutions were neutralysed and the reducing power of the sugars was 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 quantify. It was removed by centrifuging. The aqueous residue (97 ml) was acidified to 3 per cent acid with sulphuric 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 an an aliquot sample of the sugar solution indicated mainly glucose with traces of ammnose and galactose. Hydrolysate No. 4 and 5 were processed and hydrolysed in the same manner as No. 3. Hydrolysate No. 4 yielded 1.73 g and Hydrolysate No. 5 yielded 1.40 g sugars both being composed only of glucose as evidenced by GC analysis of aliquot samples.
• the undissolved residue was 0.12 g following 2 h drying in an oven at 105oC.
• the combined liquor of H-1 and H-2 yielded 2.39 g lignin powder and 135 ml of aqueous liquor.
• the molecular weigh of the lignin was 3200.
• the filtrates were neutralized to pH 8 and subjected to steam distillation in an all glass apparatus.
• the 28 ml distillate which was collected contained 0.52 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 per cent acid and boiled on a water bath for 40 min to liberate the sugars.
• After neutralization with silver carbonate an aliquot of the sugar solution was worked up for alditol acetates and the sugars analyzed by GC .
• the total sugar syrup contained a total 0.58 g of sugars of which 0.29 g was calactose, 0.25 g was glucose and 0.04 g was mannose.
• H-4 gave 1.66 g of pure glucose with only small traces of lignin, whereas H-5 gave 1.85 g glucose and no lignin. The undissolved residue was 0.18 g and was composed of 99 per cent glucose.
• the recoveries summarize as follows: H-1, 2&3 Lignin 2.79 g
• tuberpieces were air dried to about 6 per cent moisture content for better control of the solids content but if processed wet the water had to be taken into account in calculating the water content of the solvent.
• Ten to 12 g of tuber solids were placed together with 50-70 ml of solvent made up of 80:20 acetone : water and 0.02 Normal sulphuric acid.
• the contents were rapidly heated to the reaction temperature between 155°C to 220°C to determine the rate of hydrolysis of the available carbohydrate materials.
• the reaction times ranged between 60 min at 155°C to less than a minute at 220°C for dissolution where no more than about 9 to 12 per cent undissolved residue remained.
• the residue was treated with 68 to 72 per cent sulphuric acid it turned dark brown but did not dissolve even on prolonged standing. This indicated thatthe residue was not a polymeric carbohydrate.
• the resulting hydrolysate was dark to light amber brown depending on the temperature and residence time in the reaction vessel.
• the adsorbed liquor was best removed from the spongy residue which retained the original cube shape, by centrifuging and careful pressing.
• the residue was first washed with acetone and then three times with water until no further color developed.
• the residue was beaten to a pulp filtration became very difficult and a lot of solvent was required to wash the pulp free of the residual hydrolysate liquor.
• the hydrolysate liquor was palced on a flash evaporator and the solvent removed at 50°C. This caused a brown precipitate to form which was easily filtered off on ordinary filterpaper.
• the residual light amber colored aqueous phase when filtered through an activated charcoal bed could be made water clear (similarly on filtration through an ion exchange resin in H form).
• the solution was made up to a known volume and the sugar content determined by the phenol sulphuric acid method. Since the artichoke solids are about 75 per cent carbohydrate material a theoretical yield of sugars is between 8 to 10 g of free glucose sugar following the hydrolysis. Sugar recoveries ranged between 93 per cent at 220°C to 98 per cent at 180°C (hydrolysis time about 13 minutes). The dark precipitate which fell out on removal of the acetone was less than 1 per cent of the total solids subjected to the hydrolysis.
• the aqueous liquid was then filtered through activated carbon and the clear solution made up to 200 ml.
• the sugar content of the solution was determined by diluting one milliliter to 100 ml and taking a 2 ml aliquot it was mixed -with 1 ml of 5 % phenol and 5 ml of concentrated sulphuric acid.
• the absorbance of the solution was determined spectrophotometrically at 480 nm and compared to a standard calibration curve prepared with ⁇ -d-glucose.
• the total sugar recovered was 4.17 g (94% yield) and strong acid insoluble residue was 0.4 g, whereas the brown precipitate was 0.08 g.

Landscapes

• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Polymers & Plastics (AREA)
• Proteomics, Peptides & Aminoacids (AREA)
• General Health & Medical Sciences (AREA)
• Biochemistry (AREA)
• Organic Chemistry (AREA)
• Emergency Medicine (AREA)
• Health & Medical Sciences (AREA)
• Zoology (AREA)
• Animal Husbandry (AREA)
• Engineering & Computer Science (AREA)
• Food Science & Technology (AREA)
• Saccharide Compounds (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Polysaccharides And Polysaccharide Derivatives (AREA)
• Preparation Of Compounds By Using Micro-Organisms (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=36782303

Family Applications (1)

Country Status (6)

Cited By (25)

Families Citing this family (12)

Citations (4)

Family Cites Families (2)

• 1983
  • 1983-02-16 HU HU83545A patent/HU197774B/hu not_active IP Right Cessation
• 1984
  • 1984-02-16 AU AU25779/84A patent/AU579094B2/en not_active Ceased
  • 1984-02-16 EP EP84901147A patent/EP0138882A1/en not_active Withdrawn
  • 1984-02-16 WO PCT/US1984/000213 patent/WO1984003304A1/en unknown
  • 1984-03-28 CA CA000449637A patent/CA1230592A/en not_active Expired
• 1985
  • 1985-07-27 CN CN198585105752A patent/CN85105752A/zh active Pending
• 1992
  • 1992-07-30 CN CN92108976A patent/CN1082115A/zh active Pending

Patent Citations (4)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events