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Biofuel process
- 5. the process of exchanging the organic group R″ of an ester with the organic group R′ of an alcohol. These reactions are often catalyzed by the addition of an acid or base catalyst. The reaction can also be accomplished with the help of enzymes (biocatalysts) particularly lipases .
- 8. 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,Panicumvirgatum (switchgrass), Miscanthu s grass species, wood chips and the byproducts of lawn and tree maintenance are some of the more popular cellulosic materials for ethanol production.
- 10. The two ways of producing ethanol from cellulose are: • Cellulolysis processes which consist of hydrolysis on pretreated lignocellulosic materials, using enzymes to break complex cellulose into simple sugars such as glucose, followed by fermentation and distillation. •Gasification that transforms the lignocellulosic raw material into gaseous carbon monoxide and hydrogen. These gases can be converted to ethanol by fermentation or chemical catalysis. As is normal for pure ethanol production, these methods include distillation.
- 14. Alcohol fuels that are produced by fermentation of sugars derived from wheat, corn, sugar beets, sugar cane, molasses and any sugar or starch that alcoholic beverages can be made from (like potato and fruit waste, etc.). The ethanol production methods used are enzyme digestion (to release sugars from stored starches), fermentation of the sugars, distillation and drying.
Notes de l'éditeur
- Biofuels are drawing increasing attention worldwide as substitutes for petroleum-derived transportation fuels to help address energy cost, energy security and global warming concerns associated with liquid fossil fuels. The term biofuel is used here to mean any liquid fuel made from plant material that can be used as a substitute for petroleum-derived fuel. Biofuels can include relatively familiar ones, such as ethanol made from sugar cane or diesel-like fuel made from soybean oil, to less familiar fuels such as dimethyl ether (DME) or Fischer-Tropsch liquids (FTL) made from lignocellulosic biomass.
- A relatively recently popularized classification for liquid biofuels includes “first-generation” and “second-generation” fuels. There are no strict technical definitions for these terms. The main distinction between them is the feedstock used. A first-generation fuel is generally one made from sugars, grains, or seeds, i.e. one that uses only a specific (often edible) portion of the above-ground biomass produced by a plant, and relatively simple processing is required to produce a finished fuel. First-generation fuels are already being produced in significant commercial quantities in a number of countries. Second-generation fuels are generally those made from non-edible lignocellulosic biomass,1 either non-edible residues of food crop production (e.g. corn stalks or rice husks) or non-edible wholeplant biomass (e.g. grasses or trees grown specifically for energy). Second-generation fuels are not yet being produced commercially in any country.
- Is a completely natural, renewable fuel applicable in any situation where conventional petroleum diesel is used. No modifications on engine are needed. It is known chemically as a 'fatty acid methyl ester’. “Which is just a fancy way of saying it's a product made from Methanol and organic oil with fatty acid chains in it” .
- Pretreatment - it is filtered to remove dirt, charred food, and other non-oil material often found. Transesterification - involves the reaction between an alcohol and a triglyceride molecule in the presence of a base or acid catalyst. Is the process of exchanging the organic group R" of an ester with the organic group R' of an alcohol. These reactions are often catalyzed by the addition of an acid or base catalyst. Washing - is done to remove any additional soap, alcohol, or other impurities in the biodiesel. The biodiesel produced with the process described above will work in some heating and lighting equipment and may be used to fuel diesel engines. Also to minimize contamination and remove unreacted methanol. Bubble-Washing - is more aggressive than mist washing. It is done by adding a layer of water beneath the biodiesel and forming air bubbles in the water. The water is dragged up into the biodiesel in a small layer around the air bubble, which falls back down through the biodiesel when the bubble bursts at the top of the tank. Mist Washing - is the spraying of water over the top of the biodiesel and letting it settle down through the biodiesel collecting contaminates as it goes. It is more aggressive and therefore more effective at removing contaminates than static washing. Drying - to remove the water from the biodiesel. The fuel is then filtered before it can finally be used as fuel. Methanol and Catalyst – reacted to form sodium methoxide or potassium methoxide depending on the catalyst used. Catalyst used is sodium hydroxide(lye) or potassium hydroxide. The heated reaction mix is kept just above the boiling point of the alcohol (around 70 °C, 158°F) in order to speed up the reaction. Glycerin - from the oil separates from the unwashed biodiesel. The two can be separated by means of gravity with the glycerin simply drawn off from the bottom of the collecting vessel. Steps in Making Biodiesel 1. To do this, oil is simply heated to a designated temperature at 50 degree C(to help with the chemical reaction) and then a mixture of catalyst and an alcohol are added to the oil. 2. The oil, catalyst, and alcohol mixture are then mixed for a period of time (2-3 hours) and then allowed to settle (8-10 hours usually overnight). 3. If successful, the chemical reaction between the oil, alcohol, and the catalyst will have broken down the oil into several layers. The top layer will be biodiesel, chemically called an Ester, the next layer may contain soap, and the bottom layer will be glycerin. 4. Once the layering has occured, the glycerin and soap are drained off. 5. The biodiesel is then washed with either a mist-wash, a bubble-wash, or both. 6. The washing is done to remove any additional soap, alcohol, or other impurities in the biodiesel. 7. After it's been washed, it is then dried to remove any water. Commonly it is then filtered through fuel filters and is then ready to be used.
- Hydrolysis usually means the rupture of chemical bonds by the addition of water. Generally, hydrolysis is a step in the degradation of a substance. In terms of the word's derivation, hydrolysis ( /haɪˈdrɒlɨsɪs/) comes from Greek roots hydro "water" + lysis "separation". The hydrolysis of polysaccharides to soluble sugars is called "saccharification"
- 1.A "pretreatment" phase, to make the lignocellulosic material such as wood or straw amenable to hydrolysis 2.Cellulose hydrolysis (cellulolysis), to break down the molecules into sugars 3. Separation of the sugar solution from the residual materials, notably lignin 4. Microbial fermentation of the sugar solution 5.Distillation to produce roughly 95% pure alcohol 6. Dehydration by molecular sieves to bring the ethanol concentration to over 99.5% The idea of using bioethanol as a fuel is not new. In the early 20th century indeed, Henry Ford had imagined using ethanol to fuel its legendary "FORD Model T." Historically, the production of ethanol from biomass has been limited (mainly for technical reasons) to the conversion of simple sugars readily available in the soluble form (sugarcane, beets, fruit) or starch (cereals). In 2010, a genetically engineered yeast strain was developed to produce its own cellulose-digesting enzymes.[13] Assuming this technology can be scaled to industrial levels, it would eliminate one or more steps of cellulolysis, reducing both the time required and costs of production.
- Ethanol can be used in petrol engines as a replacement for gasoline; it can be mixed with gasoline to any percentage. Most existing car petrol engines can run on blends of up to 15% bioethanol with petroleum/gasoline. Ethanol has a smaller energy density than does gasoline; this fact means that it takes more fuel (volume and mass) to produce the same amount of work. Ethanol is also used to fuel bioethanol fireplaces. As they do not require a chimney and are "flueless", bio ethanol fires[5] are extremely useful for new build homes and apartments without a flue.
- Scientists have long been through with the discovery stage of the possible and beneficial processes this alternative technology had to deal. Yet consequently, scientific communities all over the globe have been still intensively conducting further researches and experiments on the most efficient sources the various established processes should yield. Although gasoline prices have slowed their meteoric rise in the past few months, they still show no sign of stopping or reversing. Diesel prices are especially high, so it is no surprise that the scramble for cheap and clean fuel alternatives is still on, and the word "biodiesel" is on many people's lips. Quantifying the benefits and costs of biofuel and biodiesel throughout their life cycles allows us not only to make sound choices today but also to identify better fuels for the future. These sources reveal a promising future for our Mother Earth. But in spite of all the awesome discoveries these technologies had brought to humanity, international organizations most especially the United Nations have declared that these are “crimes against humanity” saying it is creating food shortages and price jumps that cause millions of poor people to go hungry. Few researchers have outlined that the rocketing global demand of biodiesel would hasten the total abashment of the poor countries in terms of food allotment for its inhabitants. It is clear that humans have a commitment to the development of these alternative energy resources but it’s also clear that the world today is into struggling poverty and supporting economic development all over for extending overseas development assistance in the world. Recently, it had been a growing to make biofuel and biodiesel out from agricultural waste rather than wheat, corn, sugar cane and other food crops which we all know are staple not only for human survival but of the entire components of the food web. Moreover, despite of that unsolicited side of the picture, with much caution and strategic systems, in realizing homeostasis in every aspect it deals, that have to be developed for these energy systems proved more merits for our greater future.