Extraction energy requirements

The rates of extract involved in industrial ventilation are by nature of a high volume. It is of interest to consider the energy required to heat one cubic meter of air from, say, an outdoor temperature of -5 °C to be discharged into the space at 20 °C. 

In practice the finite-field calculation is not so simple because the higher-order terms in the induced dipole and the interaction energy are not negligible. Normally we use a number of applied fields along each axis, typically multiples of 10 " a.u., and use the standard techniques of numerical analysis to extract the required data. Such calculations are not particularly accurate, because they use numerical methods to find differentials. 

The work function, O, of a solid surface (in eV) is the minimum energy required to extract an electron from that (neutral) surface.9 10,16 23 The parameter O/e (in V) is usually called the extraction potential. 

Solvent extraction carried out in conventional contactors like mixer-settlers and columns has certain limitations, including (a) controlling optimum dispersion and coalescence, (b) purifying both phases to ensure that stable emulsions are avoided (c) temperature control within a narrow band (d) high entrained solvent losses and related environmental and process economic effects and (e) large equipment dimensions and energy requirements when the density differential or selectivity is low. 

If W is negative a pump is required if it is positive a turbine could be installed to extract energy from the system. 

Electrochemical sensors, however, currently share one key advantage an excitation signal may be imposed that can trigger a sensing reaction, and the energy required for an otherwise thermodynamically unfavorable extraction and/or binding process can be... 

The alternative fuels discussed in the following are benchmarked against gasoline and diesel from conventional crude oil. The energy requirement and GHG emissions for the supply of gasoline and diesel include the extraction of crude oil, transport to a refinery in the EU and distribution of the final fuels. The energy requirement for crude oil extraction is assumed with 1.025 MJ/MJ crude oil, and for related C02 emissions with 3.3 g/MJ. 

For WTW analysis, it is a sufficiently accurate assumption, that natural gas mainly consists of methane (CFI4). Compressed natural gas is also referred to as CNG . Natural gas is extracted, processed, transported and distributed via pipeline to the filling stations, where it is compressed to about 25 MPa. Natural gas sources may vary for different countries. Depending on the source (natural gas quality) and the transport distance (e.g., 4000 km or even 7000 km from Russia, depending on the relevant gas fields) the auxiliary energy needs or energy losses, and hence the GHG-relevant emissions can vary. For the calculation of the energy requirement and GHG emissions for the supply of natural gas, a transport distance of 4000 km is assumed. 

The phase transfer catalysis not only promotes the reactions between the reagents which are mutually insoluble in immiscible phases, but also offers a number of process advantages such as, increase in rate of reactions, increase in product specificity, lowering of energy requirement, use of inexpensive solvents and catalysts, extraction of cations or even neutral molecules from one phase to another etc. 

The major disadvantage to recovery of LNAPL by vapor extraction is the large quantity of energy required to maintain rapid volatilization of the product and airflow to transport the diluted vapors to the surface. The remediation time for this type of system tends to be quite long, often in terms of years. 

The purpose of seeking a concentrated strip solution is to reduce the energy required to recover the product from the strip solution. In the case of metal salts, precipitation, electrolysis, direct reduction, and a host of other techniques may be used to generate the final product. In the case of the extraction of organic compounds, distillation, crystallization, or similar separation methods are used. In each case, the more concentrated the strip solution, the less energy is required to recover the desired components. 

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