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Fischer–Tropsch Process
The Fischer–Tropsch process (FT) is a collection of chemical reactions that converts a mixture of carbon monoxide and hydrogen, known as syngas, into liquid hydrocarbons. These reactions occur in the presence of metal catalysts, typically at temperatures of and pressures of one to several tens of atmospheres. The Fischer–Tropsch process is an important reaction in both coal liquefaction and gas to liquids technology for producing liquid hydrocarbons. In the usual implementation, carbon monoxide and hydrogen, the feedstocks for FT, are produced from coal, natural gas, or biomass in a process known as gasification. The process then converts these gases into synthetic lubrication oil and synthetic fuel. This process has received intermittent attention as a source of low-sulfur diesel fuel and to address the supply or cost of petroleum-derived hydrocarbons. Fischer–Tropsch process is discussed as a step of producing carbon-neutral liquid hydrocarbon fuels from CO2 and hydrogen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hans Tropsch
Hans Tropsch (October 7, 1889 – October 8, 1935) was a chemist responsible, along with Franz Fischer, for the development of the Fischer–Tropsch process. Life Tropsch was born in Plan bei Marienbad, Sudet-German Bohemia at that time part of Austria-Hungary now Czech Republic. He studied at the German Charles-Ferdinand University in Prague and the German Technical University in Prague from 1907 until 1913. He received his Ph.D for work with Hans Meyer. Tropsch worked in a dye factory in Mülheim in 1916–1917, then for a few months at the Kaiser Wilhelm Institute for Coal Research. From 1917 to 1920, Tropsch worked in a tar distillery of the Rütgers company in Niederau, but returned to the Kaiser Wilhelm Institute for Coal Research in 1920, staying until 1928. There he worked with both Franz Fischer and Otto Roelen. It was during this time that the ground-breaking inventions of the Fischer–Tropsch process were patented. In 1928, Tropsch became professor at the ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dissociative Adsorption
Dissociative adsorption is a process in which a molecule adsorbs onto a surface and simultaneously dissociates into two or more fragments. This process is the basis of many applications, particularly in heterogeneous catalysis reactions. The dissociation involves cleaving of the molecular bonds in the adsorbate, and formation of new bonds with the substrate. Breaking the atomic bonds of the dissociating molecule requires a large amount of energy, thus dissociative adsorption is an example of chemisorption, where strong adsorbate-substrate bonds are created. These bonds can be atomic, ionic or metallic in nature. In contrast to dissociative adsorption, in molecular adsorption the adsorbate stays intact as it bonds with the surface. Often, a molecular adsorption state can act as a precursor in the adsorption process, after which the molecule can dissociate only after sufficient additional energy is available. A dissociative adsorption process may be '' homolytic'' or '' heterol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aliphatic Compound
In organic chemistry, hydrocarbons ( compounds composed solely of carbon and hydrogen) are divided into two classes: aromatic compounds and aliphatic compounds (; G. ''aleiphar'', fat, oil). Aliphatic compounds can be saturated (in which all the C-C bonds are single, requiring the structure to be completed, or 'saturated', by hydrogen) like hexane, or unsaturated, like hexene and hexyne. Open-chain compounds, whether straight or branched, and which contain no rings of any type, are always aliphatic. Cyclic compounds can be aliphatic if they are not aromatic. Structure Aliphatics compounds can be saturated, joined by single bonds ( alkanes), or unsaturated, with double bonds ( alkenes) or triple bonds ( alkynes). If other elements ( heteroatoms) are bound to the carbon chain, the most common being oxygen, nitrogen, sulfur, and chlorine, it is no longer a hydrocarbon, and therefore no longer an aliphatic compound. However, such compounds may still be referred to as al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reaction Enthalpy
The standard enthalpy of reaction (denoted \Delta H_^\ominus) for a chemical reaction is the difference between total product and total reactant molar enthalpies, calculated for substances in their standard states. The value can be approximately interpreted in terms of the total of the chemical bond energies for bonds broken and bonds formed. For a generic chemical reaction :\nu_ \text + \nu_ \text ~+ ~... \rightarrow \nu_ \text + \nu_ \text ~+ ~... the standard enthalpy of reaction \Delta H_^\ominus is related to the standard enthalpy of formation \Delta_ H^\ominus values of the reactants and products by the following equation: : \Delta H_^\ominus = \sum_ \nu_p\Delta_ H_^ - \sum_ \nu_r\Delta_ H_^ In this equation, \nu_i are the stoichiometric coefficients of each product and reactant. The standard enthalpy of formation, which has been determined for a vast number of substances, is the change of enthalpy during the formation of 1 mole of the substance from its constit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exothermic Reaction
In thermochemistry, an exothermic reaction is a "reaction for which the overall standard enthalpy change Δ''H''⚬ is negative." Exothermic reactions usually release heat. The term is often confused with exergonic reaction, which IUPAC defines as "... a reaction for which the overall standard Gibbs energy change Δ''G''⚬ is negative." A strongly exothermic reaction will usually also be exergonic because Δ''H''⚬ makes a major contribution to Δ''G''⚬. Most of the spectacular chemical reactions that are demonstrated in classrooms are exothermic and exergonic. The opposite is an endothermic reaction, which usually takes up heat and is driven by an entropy increase in the system. Examples Examples are numerous: combustion, the thermite reaction, combining strong acids and bases, polymerizations. As an example in everyday life, hand warmers make use of the oxidation of iron to achieve an exothermic reaction: :4Fe + 3O2 → 2Fe2O3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcohols
In chemistry, an alcohol (), is a type of organic compound that carries at least one hydroxyl () functional group bound to a Saturated and unsaturated compounds, saturated carbon atom. Alcohols range from the simple, like methanol and ethanol, to complex, like sugar alcohols and cholesterol. The presence of an OH group strongly modifies the properties of Hydrocarbon, hydrocarbons, conferring Hydrophile, hydrophilic (water-loving) properties. The OH group provides a site at which many reactions can occur. History The flammable nature of the exhalations of wine was already known to ancient natural philosophers such as Aristotle (384–322 BCE), Theophrastus (–287 BCE), and Pliny the Elder (23/24–79 CE). However, this did not immediately lead to the isolation of alcohol, even despite the development of more advanced distillation techniques in second- and third-century Roman Egypt. An important recognition, first found in one of the writings attributed to Jabir ibn Hayyan, J� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkenes
In organic chemistry, an alkene, or olefin, is a hydrocarbon containing a carbon–carbon double bond. The double bond may be internal or at the terminal position. Terminal alkenes are also known as Alpha-olefin, α-olefins. The International Union of Pure and Applied Chemistry (IUPAC) Preferred IUPAC name, recommends using the name "alkene" only for Open-chain compound, acyclic hydrocarbons with just one double bond; alkadiene, alkatriene, etc., or polyene for acyclic hydrocarbons with two or more double bonds; cycloalkene, cycloalkadiene, etc. for Cyclic compound, cyclic ones; and "olefin" for the general class – cyclic or acyclic, with one or more double bonds. Acyclic alkenes, with only one double bond and no other functional groups (also known as mono-enes) form a homologous series of hydrocarbons with the general formula with ''n'' being a >1 natural number (which is two hydrogens less than the corresponding alkane). When ''n'' is four or more, isomers are possible, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diesel Fuel
Diesel fuel, also called diesel oil, heavy oil (historically) or simply diesel, is any liquid fuel specifically designed for use in a diesel engine, a type of internal combustion engine in which fuel ignition takes place without a spark as a result of compression of the inlet air and then injection of fuel. Therefore, diesel fuel needs good compression ignition characteristics. The most common type of diesel fuel is a specific fractional distillation, fractional distillate of petroleum fuel oil, but alternatives that are not derived from petroleum, such as biodiesel, biomass to liquid (BTL) or gas to liquid (GTL) diesel are increasingly being developed and adopted. To distinguish these types, petroleum-derived diesel is sometimes called petrodiesel in some academic circles. Diesel is a high-volume product of oil refineries. In many countries, diesel fuel is standardized. For example, in the European Union, the standard for diesel fuel is EN 590. Ultra-low-sulfur diesel (ULSD) i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methane
Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The abundance of methane on Earth makes it an economically attractive fuel, although capturing and storing it is difficult because it is a gas at standard temperature and pressure. In the Earth's atmosphere methane is transparent to visible light but absorbs infrared radiation, acting as a greenhouse gas. Methane is an Organic chemistry, organic Organic compound, compound, and among the simplest of organic compounds. Methane is also a hydrocarbon. Naturally occurring methane is found both below ground and under the seafloor and is formed by both geological and biological processes. The largest reservoir of methane is under the seafloor in the form of methane clathrates. When methane reaches the surface and the Atmosphere of Earth, atmosphere, it is known as atmospheric methane. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Higher Alkanes
320px Higher alkanes are alkanes with a high number of carbon atoms. It is common jargon. One definition says higher alkanes are alkanes having nine or more carbon atoms. Thus, according to this definition, nonane is the lightest higher alkane. As pure substances, higher alkanes are rarely significant, but they are major components of useful lubricants and fuels. Synthesis The preparation of specific long-chain hydrocarbons typically involves manipulations of long chain precursors or the coupling of two medium-chain components. For the first case, fatty acids can be a source of higher alkanes via decarboxylation reaction. Such processes have been investigated as a route to biodiesel. Fatty acid esters and fatty acid nitriles react with long chain Grignard reagents to give, after suitable workup, long-chain ketones. The Wolff-Kishner Reaction provides a way to remove the ketone functionality, giving long-chain hydrocarbons. Even-numbered, long-chain hydrocarbons can a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkane
In organic chemistry, an alkane, or paraffin (a historical trivial name that also has other meanings), is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in which all the carbon–carbon bonds are single. Alkanes have the general chemical formula . The alkanes range in complexity from the simplest case of methane (), where ''n'' = 1 (sometimes called the parent molecule), to arbitrarily large and complex molecules, like hexacontane () or 4-methyl-5-(1-methylethyl) octane, an isomer of dodecane (). The International Union of Pure and Applied Chemistry (IUPAC) defines alkanes as "acyclic branched or unbranched hydrocarbons having the general formula , and therefore consisting entirely of hydrogen atoms and saturated carbon atoms". However, some sources use the term to denote ''any'' saturated hydrocarbon, including those that are either monocyclic (i.e. the cycloalkanes) or polycycl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
