Xplore Abstract - Effect of alcohol on cellulose hydrolysis in super/subcritical alcohol-water mixtures. The focus of this work was on investigating the effects of different types of alcohol on the cellulose hydrolysis in supercritical/subcritical alcohol-water mixtures by selecting methanol, ethanol, and isopropanol as co-solvents. The experiments were conducted in a batch reactor under the following conditions: 5% mass ratio, 0.58 min reaction time and stirring speed 600 r/min. The experimental results showed that the reducing sugar yield was very low when the alcohol mole fraction in the alcohol-water mixture was more than 0.8, however, the yield turned very high when the mole fraction was less than 0.6.
Critical parameters of alcohol-water mixtures revealed that the alcohol-water mixtures were in the supercritical state when the alcohol mole fraction was above 0.8 at 250°C. As a contrast, the mixtures were in the sub-critical state if the mole fraction turned into 0.6. Therefore, further investigations were carried out in sub-critical alcohol-water mixtures. Cellulose hydrolysis in subcritical and supercritical water. Abstract In this paper we propose a new method to hydrolyze cellulose rapidly in supercritical water (SCW) to recover glucose, fructose and oligomers (cellobiose, cellotriose, cellotetraose, etc.). Cellulose decomposition experiments were conducted with a flow type reactor in the range of temperature from 290 to 400°C at 25 MPa. A high pressure slurry feeder was developed to feed the cellulose–water slurries.
Hydrolysis product yields (around 75%) in supercritical water were much higher than those in subcritical water. At a low temperature region, the glucose or oligomer conversion rate was much faster than the hydrolysis rate of cellulose. Keywords Cellulose; Hydrolysis; Supercritical water; Kinetics Copyright © 1998 Elsevier Science B.V. Supercritical fluid. Properties[edit] In general terms, supercritical fluids have properties between those of a gas and a liquid.
In Table 1, the critical properties are shown for some components, which are commonly used as supercritical fluids. Table 2 shows density, diffusivity and viscosity for typical liquids, gases and supercritical fluids. In addition, there is no surface tension in a supercritical fluid, as there is no liquid/gas phase boundary. By changing the pressure and temperature of the fluid, the properties can be "tuned" to be more liquid- or more gas-like. One of the most important properties is the solubility of material in the fluid. Solubility in a supercritical fluid tends to increase with density of the fluid (at constant temperature). All supercritical fluids are completely miscible with each other so for a mixture a single phase can be guaranteed if the critical point of the mixture is exceeded. Tc(mix) = (mole fraction A) x TcA + (mole fraction B) x TcB. Phase diagram[edit] Figure 1. Patent US1443881 - Fermentation of cellulose - Google Patents.
Patented Jan. 31), 1923. ' rnnmnn'rarron or cELLuLosE. No Drawing. duction of acetic acid as the main fattyacid is possible and this fermentation has frequently been studied; however, the statements as to the conditions under which it occurs are conflicting and a practical manufacturing process cannot be deduced from them. By the present invention the fermentation of cellulose is conducted under the following conditions 1. The fermenting mass is aerated in a known manner such as by forcing air, preferably inthe form of very fine bubbles, through the mass, or by carrying on the fermentation in a shallow vessel in such a manner that a comparatively large surface is exposed tothe air. 2. 3. 4;. Y nitrogen may be in the form' of organic'ov when the action may Application filed September 29, 1919.
Inptrganic compounds or as ammonium sa S. .5. Halfstuff, 3 lbs. precipitated chalk, i lb glucose; the necessary mineral nutrient consisting of lb. each of ammonium chloride, I claim 1. 2. 3. 4. Patent US1443881 - Fermentation of cellulose - Google Patents. The Journal of Agricultural Science - Abstract - The fermentation of cellulose by thermophilic bacteria. Research Article The fermentation of cellulose by thermophilic bacteria J. A. Viljoena1, E. B. a1 (From the Departments of Agricultural Bacteriology, and Agricultural Chemistry, University of Wisconsin, Madison, Wisconsin.) 1. 2. 3. 4. 5. 6. 7. 8. 9. Direct fermentation of cellulose to ethanol by Fusarium oxysporum. Fermentation Challenge: Making Ethanol from Cellulose | Great Lakes Bioenergy Research Center. Ethanol From Cellulose: A General Review. Index | Search | Home | Table of Contents Badger, P.C. 2002. Ethanol from cellulose: A general review. p. 17–21. In: J. Janick and A. Whipkey (eds.), Trends in new crops and new uses.
ASHS Press, Alexandria, VA. P.C. The use of ethanol as an alternative motor fuel has been steadily increasing around the world for a number of reasons. Ethanol can be made synthetically from petroleum or by microbial conversion of biomass materials through fermentation. Fermentation involves microorganisms that use the fermentable sugars for food and in the process produces ethanol and other byproducts. One example of a sugar feedstock is sugarcane.
Although fungi, bacteria, and yeast microorganisms can be used for fermentation, a specific yeast (Saccharomyces cerevisiae also known as Bakers’ yeast, since it is commonly used in the baking industry) is frequently used to ferment glucose to ethanol. Another potential ethanol feedstock is starch. Table 1. Table 2. Table 3. Kraft process. The kraft process (also known as kraft pulping or sulfate process)[1] is a process for conversion of wood into wood pulp consisting of almost pure cellulose fibers. It entails treatment of wood chips with a mixture of sodium hydroxide and sodium sulfide, known as white liquor, that breaks the bonds that link lignin to the cellulose. History[edit] The kraft process (so called because of the superior strength of the resulting paper, from the German word Kraft) was invented by Carl F. Dahl in 1879 in Danzig, Prussia, Germany. The process[edit] Continuous Kraft pulp mill Impregnation[edit] Common wood chips used in pulp production are 12–25 millimetres (0.47–0.98 in) long and 2–10 millimetres (0.079–0.39 in) thick.
Cooking[edit] The wood chips are then cooked in huge pressurized vessels called digesters. Net reaction in depolymerization of lignin by SH- (Ar = aryl, R = alkyl groups). Recovery process[edit] 1. This reaction is similar to thermochemical sulfate reduction in geochemistry. 2. 3. 4. Organosolv. In industrial paper-making processes, organosolv is a pulping technique that uses an organic solvent to solubilise lignin and hemicellulose. It has been considered in the context of both pulp and paper manufacture and biorefining for subsequent conversion of cellulose to fuel ethanol. The process was invented by Theodore Kleinert[1] as an environmentally benign alternative to kraft pulping. Organosolv has several advantages when compared to other popular methods such as kraft or sulfite pulping.
In particular, the ability to obtain relatively high quality lignin adds value to a process stream otherwise considered as waste. Organosolv solvents are easily recovered by distillation leading to less water pollution and elimination of the odour usually associated with kraft pulping. Solvents[edit] Organosolv pulping involves contacting a lignocellulosic feedstock such as chipped wood with an aqueous organic solvent at temperatures ranging from 140–220°C. Organosolv for pulp production[edit] Suburban grass clippings, landfill or ethanol? Well, it might be time to do some more intensive research! David Blumes' book has info on starch conversion methods, and makes many suggestions for crops/plants adapted to desertified or extreme/marginal land and conditions, but one would really also need to look closer to home for indigenous and/or locally developed crops easily available for trialling and eventual use.
Cassava may also be a possibility. Sometimes the answer lies in plants already adapted to the environment but overlooked because they have been regarded as pests or weeds. You would have to run a series of small scale trials of various crops, ring fenced, or bird-clothed etc (vineyards or other local food producers may have good examples?) Advice too from local farmers could be very useful, and if arrowroot is resistant to pests, then it may well be a useful "adjunct" crop that suits low management.
This may be interesting possiblibility, from another forum, about agave (woo hoo! Rudie. Wood chips to biofuel in hours -- ScienceDaily. Until now, it has taken weeks to make biofuel from trees. This slow pace has been a bottleneck for the industry. Researchers from the Norwegian University of Science and Technology have now shortened the process to a few hours. "The time when we use food stock to make biofuel to power a car may soon come to an end. Currently, maize and sugar cane are used to produce biofuel," says Finn Lillelund Aachmann, a biotechnology researcher at the Norwegian University of Science and Technology.
Aachmann thinks that the desire for people to have environmentally friendly fuel should not be at the expense of food. Tiny Wood Chip Machine The biggest challenge in making biofuel from wood to date has been that it is a time-consuming process. The super enzyme works like a tiny wood machine that scratches up the surface of the wood so that other enzymes can gain access and break the hard surface down into sugar. A Need For Deeper Understanding Strengthened Cooperation. Making Ethanol from Wood Chips. Experimental methods for converting wood chips and grass into ethanol will soon be tested at production scale. Mascoma Corporation, based in Cambridge, MA, is building demonstration facilities that will have the capacity to produce about one-half to two million gallons of ethanol a year from waste biomass. The startup recently received $30 million in venture-capital money, which is fueling its scale-up plans.
While Mascoma has not achieved its ultimate goal of using a single genetically engineered organism to convert wood chips and other cellulosic raw materials into ethanol, the company has developed genetically modified bacteria that can speed up part of the process of producing ethanol. The optimized process shows enough promise to invest in scaling up the technology, says Colin South, Mascoma’s president.
Corn grain, the current source of ethanol in the United States, requires large amounts of land and energy to produce. Cellulosic ethanol. Cellulosic ethanol is a biofuel produced from wood, grasses, or the inedible parts of plants. It is a type of biofuel produced from lignocellulose, a structural material that comprises much of the mass of plants. Lignocellulose is composed mainly of cellulose, hemicellulose and lignin. Corn stover, Panicum virgatum (switchgrass), Miscanthus grass species, wood chips and the byproducts of lawn and tree maintenance are some of the more popular cellulosic materials for ethanol production.
Production of ethanol from lignocellulose has the advantage of abundant and diverse raw material compared to sources such as corn and cane sugars, but requires a greater amount of processing to make the sugar monomers available to the microorganisms typically used to produce ethanol by fermentation. Switchgrass and Miscanthus are the major biomass materials being studied today, due to their high productivity per acre. History[edit] US President George W. Production methods[edit] Pretreatment[edit] Bacterial cellulose hydrolysis in anaerobic... [Ann N Y Acad Sci. 2008. Hydrolysis. Hydrolysis (/haɪˈdrɒlɨsɪs/; from Greek hydro-, meaning "water", and lysis, meaning "separation") usually means the cleavage of chemical bonds by the addition of water.
Where a carbohydrate is broken into its component sugar molecules by hydrolysis (e.g. sucrose being broken down into glucose and fructose), this is termed saccharification. Generally, hydrolysis or saccharification is a step in the degradation of a substance. Types[edit] Usually hydrolysis is a chemical process in which a molecule of water is added to a substance. Sometimes this addition causes both substance and water molecule to split into two parts. In such reactions, one fragment of the target molecule (or parent molecule) gains a hydrogen ion. Salts[edit] Strong acids also undergo hydrolysis. Esters and amides[edit] Acid–base-catalysed hydrolyses are very common; one example is the hydrolysis of amides or esters.
Perhaps the oldest commercially practiced example of ester hydrolysis is saponification (formation of soap). Biofuel. A biofuel is a fuel that contains energy from geologically recent carbon fixation. These fuels are produced from living organisms. Examples of this carbon fixation occur in plants and microalgae. These fuels are made by a biomass conversion (biomass refers to recently living organisms, most often referring to plants or plant-derived materials). This biomass can be converted to convenient energy containing substances in three different ways: thermal conversion, chemical conversion, and biochemical conversion. Bioethanol is an alcohol made by fermentation, mostly from carbohydrates produced in sugar or starch crops such as corn, sugarcane, or sweet sorghum. Biodiesel can be used as a fuel for vehicles in its pure form, but it is usually used as a diesel additive to reduce levels of particulates, carbon monoxide, and hydrocarbons from diesel-powered vehicles.
Liquid fuels for transportation[edit] First-generation biofuels[edit] Ethanol[edit] Biodiesel[edit] Other bioalcohols[edit] Ethanol fermentation. In ethanol fermentation, one glucose molecule breaks down into two pyruvates (1). The energy from this exothermic reaction is used to bind inorganic phosphates to ADP and convert NAD+ to NADH. The two pyruvates are then broken down into two acetaldehydes and give off two CO2 as a waste product (2). The two acetaldehydes are then converted to two ethanol by using the H- ions from NADH; converting NADH back into NAD+ (3). Alcoholic fermentation, also referred to as ethanol fermentation, is a biological process in which sugars such as glucose, fructose, and sucrose are converted into cellular energy and thereby produce ethanol and carbon dioxide as metabolic waste products. Because yeasts perform this conversion in the absence of oxygen, alcoholic fermentation is considered an anaerobic process.
Alcoholic fermentation occurs in the production of alcoholic beverages and ethanol fuel, and in the rising of bread dough. Grapes fermenting during the production of exempt of wine. Bread Baking[edit] Fermentation. Scientists discover a novel way to make ethanol without corn or other plants. Ethanol Feedstocks. Anaerobic digestion.