Product energy consumption

Basic Electronic Devices. Transistor-based digital technology has replaced older vacuum tube technology, except in rare instances in which a transistorized device cannot perform the same function. Electronic circuits based on vacuum tubes could carry out essentially the same individual operations as transistors, but they were severely limited by physical size, heat production, energy consumption, and mechanical failure. Nevertheless, vacuum tube technology was the basic technology that produced radio. 

Theoretic energy consumption can be divided into theoretic energy consumption of process and product. The theoretic energy consumption of process refers to the energy consumption by unit product made by raw materials (may or may not be the primary standard substance in environment), i.e. the ideal power of process. The product energy consumption refers to the energy consumption by unit product made from raw materials in environment state. The difference between them is... 

Regardless of what kinds of materials and methods are used, the production process of ammonia is irreversible. Therefore, the actual product energy consumption is... 

Consider a three-product separation as in Fig. 5.11a in which the lightest and heaviest components are chosen to be the key separation in the first column. Two further columns are required to produce pure products (see Fig. 5.11a). However, note from Fig. 5.11a that the bottoms and overheads of the second and third columns are both pure B. Hence the second and third columns could simply be connected and product B taken as a sidestream (see Fig. 5.116). The arrangement in Fig. 5.116 is known as a prefractionator arrangement. Note that the first column in Fig. 5.116, the prefractionator, has a partial condenser to reduce the overall energy consumption. Comparing the prefractionator arrangement in Fig. 5.116 with the conventional... 

Both the side-rectifier and side-stripper arrangements have been shown to reduce the energy consumption compared with simple two-column arrangements. This results from reduced mixing losses in the first (main) column. As with the first column of the simple sequence, a peak in composition occurs with the middle product. Now, however, advantage of the peak is taken by transferring material to the side-rectifier or side-stripper. 

Trends in commercial fuel, eg, fossd fuel, hydroelectric power, nuclear power, production and consumption in the United States and in the Organization of Economic Cooperation and Development (OECD) countries, are shown in Tables 2 and 3. These trends indicate (6,13) (/) a significant resurgence in the production and use of coal throughout the U.S. economy (2) a continued decline in the domestic U.S. production of cmde oil and natural gas lea ding to increased imports of these hydrocarbons (qv) and (J) a continued trend of energy conservation, expressed in terms of energy consumed per... 

Electrode consumption for ferrous melting a-c furnaces usually averages 2.5—6 kg/1 of molten metal dependent on the particular furnace practices. D-c furnaces have electrode consumptions that are about 30% lower for similar operations. A typical energy consumption for a typical high productivity ministeel mill practice is 400 kW h/t. In comparison, power consumptions exceeding 600 kW h/t ia foundries is not unusual because of longer furnace cycle times. 

Comparison to the Raschig Process. The economics of this peroxide process in comparison to the Raschig or hypochlorite—ketazine processes depend on the relative costs of chlorine, caustic, and hydrogen peroxide. An inexpensive source of peroxide would make this process attractive. Its energy consumption could be somewhat less, because the ketazine in the peroxide process is recovered by decantation rather than by distillation as in the hypcochlorite process. A big advantage of the peroxide process is the elimination of sodium chloride as a by-product this is important where salt discharge is an environmental concern. In addition to Elf Atochem, Mitsubishi Gas (Japan) uses a peroxide process. 

Some processes use only one reactor (57) or a combination of liquid- and vapor-phase reactors (58). The goal of these schemes is to reduce energy consumption and capital cost. Hydrogenation normally is carried out at 2—3 MPa (20—30 atm). Temperature is maintained at 300—350°C to meet a typical specification of less than 500 ppm benzene in the product at higher temperatures, thermodynamic equiUbrium shifts to favor benzene and the benzene specification is impossible to attain. Also, at higher temperatures, isomerization of cyclohexane to methylcyclopentane occurs typically there is a 200 ppm specification limit on methylcyclopentane content. 

The production and consumption of LPG in the United States increased dramatically from its early beginnings in the 1930s until the international energy crises of the 1970s when rising prices and regulatory restraints resulted in reduced domestic production. However, total consumption, including imports. 

Usually the specific energy consumption, is reported in kWh /kg of product ... 

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