Some time ago, I asked for a definition of thermodynamic reversibility without mentioning entropy, and a user came up with the following formal definition of a reversible process:. Definition: Reversible process means that given the outside controllable mechanical, electrical, magnetic, chemical, etc., macroscopic parameters hat x_1,hat x_1,hat x_2,...,hat x_n of the surroundings and its ...
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Other idealized processes can be represented by pV curves; Table summarizes the most common reversible processes. Summary of Simple Thermodynamic Processes. Process. Constant Quantity and Resulting Fact. Isobaric. Constant pressure W =pΔV W = p Δ V. Isochoric. Constant volume W = 0 W = 0. Isothermal.
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within the cycle). Such a process, which involves the dissipation of energy, is classifled as irreversible with respect to an inflnitesimal change in the external conditions. More generally, reversibility means that it is possible to pass from one state to another without appreciable deviation from equilibrium.
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The daily consumption of coal is calculated using the information that each day there is × 10 14 J of heat transfer from coal. In the combustion process, we have C + O 2 → CO 2. So every 12 kg of coal puts 12 kg + 16 kg + 16 kg = 44 kg of CO 2 into the atmosphere. Solution for Part 3. The daily coal consumption is
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Coal Gasification. It is the process of reacting coal with minimal oxygen, air, steam, carbon dioxide, or the combination of these gases at or above 700°C to produce gaseous products used as an energy source ( Mishra et al., 2018). The gasification of coal produces the products like hydrogen, liquid fuels, and chemicals.
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An irreversible process is what we encounter in reality almost all the time. The system and its environment cannot be restored to their original states at the same time. Because this is what happens in nature, it is also called a natural process. The sign of an irreversible process comes from the finite gradient between the states occurring in ...
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Hydrogenation is a chemical reaction between molecular hydrogen (H 2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organic compounds.
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ii. The flower blooming is an irreversible change because flowers cannot turn back into buds. iii. When milk is not refrigerated, it spoils quickly, especially in the summer. This is known as curdling or sour milk, and it is an irreversible process. If we want to make cottage cheese or paneer, we can curdle milk by adding lemon juice. iv.
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The work of expansion can be depicted graphically as the area under the pV curve depicting the expansion. Comparing examples (PageIndex{1}) and (), for which the initial and final volumes were the same, and the constant external pressure of the irreversible expansion was the same as the final pressure of the reversible expansion, such a graph looks as follows.
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A process that is not reversible is said to be irreversible. We distinguish between two kinds of irreversible processes. A process that cannot occur under a given set of conditions is said to be an impossible process. A process that can occur, but does not do so reversibly, is called a possible process or a spontaneous process.
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Irreversible Process. Irreversible processes are a result of diverging away from the equilibrium, hence decreasing the sum of total work done and could be a thermodynamic process that withdraws from equilibrium. Allnatural forms such as conduction, radiation, radioactive decay, etc. are irreversible. Adding to it, all practical forms such as ...
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The Department of Energy explains that coal gasification is a thermochemical process in which the gasifier's heat and pressure break down coal into its chemical constituents. The resulting "syngas" is comprised primarily of carbon monoxide and hydrogen, and occasionally other gaseous compounds. Proponents of coal gasification say that ...
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After cooling, the oxidation reaction of coal continues, which verifies that the oxidation process of coal is irreversible and can also explain why oxidized coal is more prone to spontaneous combustion. Value ... The free radical reactions can explain the chem. process of coal at lowtemp. oxidn. ESR (ESR) spectroscopy was used to ...
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Gasification of coal in a bath of molten sodium carbonate through which steam is passed is the basis of the Kellogg Coal Gasification process. The bath of moiten salt strongly catalyzes the basic ...
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After coal is mined, is it ready to be shipped. If the mine is close to a destination, trucks can carry the load. Using conveyors to move coal is another option for shorter distances. In 68 percent of cases, coal is transported by the railroad. This can be very expensive. Sometimes the cost of shipping coal by train is more than the mining costs.
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The combustion of fossil fuels is an example of an irreversible process in nature, as it involves a chemical reaction that permanently changes the composition of the fuel and releases energy that cannot be fully recovered.. When fossil fuels, such as coal or oil, are burned, they undergo a chemical reaction with oxygen in the air, releasing energy in the form of heat and light.
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In science, a process that is not reversible is called concept arises frequently in complex natural processes are irreversible, although a phase transition at the coexistence temperature ( melting of ice cubes in water) is well approximated as reversible. In thermodynamics, a change in the thermodynamic state of a system and all of its surroundings ...
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The greaterthan sign denotes an irreversible process. dS is the change of entropy of the closed system. Combining these general forms of the first two laws of thermodynamics results in an expression that is very useful for determining the conditions for equilibrium and stability of systems, namely, the fundamental relation of thermodynamics: ...
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Irreversible Process. Such an irreversible process is the nonisentropic compression in the compressor, which results in larger work input and an additional vapor superheating that increases h2 and thus decreases the COP. From: Encyclopedia of Energy, 2004. Related terms: Energy Engineering; Battery (Electrochemical Energy Engineering) Oxidation ...
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Selforganization. Order and disorder. Category. v. t. e. In thermodynamics, a reversible process is a process, involving a system and its surroundings, whose direction can be reversed by infinitesimal changes in some properties of the surroundings, such as pressure or temperature. [1] [2] [3] Throughout an entire reversible process, the system ...
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An irreversible process is what we encounter in reality almost all the time. The system and its environment cannot be restored to their original states at the same time. Because this is what happens in nature, it is also called a natural process. The sign of an irreversible process comes from the finite gradient between the states occurring in ...
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Coal is a nonrenewable energy source that takes millions of years to create. It is a combustible black or brownishblack sedimentary rock composed mostly of carbon and hydrocarbons. ... Finding coal reserves is a long process of exploring, mapping, and drilling. It often starts with the creation of a geological map of an area that may contain ...
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Reversible processes: A thermodynamic process can be considered reversible only if it possible to retrace the path in the opposite direction in such a way that the system and surroundings pass through the same states as in the initial, direct process. Irreversible processes: All natural processes are irreversible. Irreversible processes cannot be plotted in a PV diagram, because these ...
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An example of an irreversible process (non quasistatic process) It should be clear from Fig. and that a system can be restored to its initial state following a reverse process, regardless of whether the process is reversible or irreversible. But the surroundings is restored back to its initial state only in the case of a ...
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The Global Stocktake broadly refers to a thorough assessment of how much progress countries are making toward the Paris Agreement targets, which committed countries to limiting global warming to below 2 degrees Celsius and ideally to compared to the preindustrial era. The process consists of three components.
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Figure (PageIndex{3}): (a) Heat transfer from a hot object to a cold one is an irreversible process that produces an overall increase in entropy. (b) The same final state and, thus, the same change in entropy is achieved for the objects if reversible heat transfer processes occur between the two objects whose temperatures are the same as the ...
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An irreversible process includes the permanent change in the size, shape, or state of any substance that can not be reversed or undone. ... On heating, coal tar melts, which is a change that can be undone. This is due to the fact that hot, molten coal tar solidifies once it has cooled. This process too is a common example of reversible changes.
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In a standard floatsink analysis, set amounts of the representative coal sample are crushed to a specified particle size and placed in liquids of known density or across a range of densities. Coal has relatively low density or specific gravity ( to ) compared to other rocks such as shale ( to ) or minerals such as pyrite ( to ).
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A material supplier from Belgium would like to produce limestone powder for his custome...
India is rich in various mineral resources and it is an important mineral processing market
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