Industry, energy consumption

Table 10. United States Portland Cement Industry Energy Consumption, %...

EA Griffin. Can we use biotechnology to reduce industrial energy consumption Tappi 7 68 56-59, 1985. 

A fraction of 45 % of all industrial energy consumption in the US is used at temperatures below 300 C, a temperature compatible with LWRs. The huge hydrocarbon reserves that exist in the USA in the form of coal and natural gas could be easily used for effective alternate transportation fuel production. 

The purpose of chemical processes is not to make chemicals The purpose is to make money. However, the profit must he made as part of a sustainable industrial activity which retains the capacity of ecosystems to support industrial activity and life. This means that process waste must be taken to its practical and economic minimum. Relying on methods of waste treatment is usually not adequate, since waste treatment processes tend not so much to solve the waste problem but simply to move it from one place to another. Sustainable industrial activity also means that energy consumption must be taken to its practical and economic minimum. Chemical processes also must not present significant short-term or long-term hazards, either to the operating personnel or to the community. 

Minimising energy consumption per ton of alurnina while maintaining a steam-power balance is an industry-wide, ongoing effort. Reduction of steam consumption has been limited by the cost of purchased power to compensate for loss of power generation. 

In most cases, CVD reactions are activated thermally, but in some cases, notably in exothermic chemical transport reactions, the substrate temperature is held below that of the feed material to obtain deposition. Other means of activation are available (7), eg, deposition at lower substrate temperatures is obtained by electric-discharge plasma activation. In some cases, unique materials are produced by plasma-assisted CVD (PACVD), such as amorphous siHcon from silane where 10—35 mol % hydrogen remains bonded in the soHd deposit. Except for the problem of large amounts of energy consumption in its formation, this material is of interest for thin-film solar cells. Passivating films of Si02 or Si02 Si N deposited by PACVD are of interest in the semiconductor industry (see Semiconductors). 

TABLE 27-23 Average Energy Consumption for Various Industries Using Direct Heat... 

It is in the second two of these cost components that, in relation to other materials, plastics can offer particular advantages. Fabrication costs include power, labour, consumables, etc and Table 1.10 shows that, in terms of the overall energy consumption, plastics come out much better than metals. Performance costs relate to servicing, warranty claims, etc. On this basis plastics can be very attractive to industries manufacturing consumer products because they can offer advantages such as colour fasmess, resilience, toughness, corrosion resistance and uniform quality - all features which help to ensure a reliable product. 

A characteristic of many industrial halls is that zones of occupancy take up only a small portion of the room volume and height. In addition, the flows are normally buoyancy dominated. This results in a vertical temperature stratification that can be utilized for room air conditioning design in order to achieve effective climatization along with low energy consumption. 

Demand-controlled ventilation (DCV) is one approach to reduce energy consumption due to ventilation, that is gaining popularity in both industrial and nonindustrial applications. It is used in cases where ventilation requirements vary with time, regularly or irregularly. The control is based on a specified level of indoor air quality by means of continuous measurement of the parameters, that are expected to primarily determine the lAQ, such as the concentration of the main contaminant liberated from the production process. The principle is thus similar to the one in some better-known nonindustrial applications, e.g., CO2 levels in rooms with dense human occupancy (theaters, classrooms, etc.) or nicotine concentration in smoking rooms. See also Section 9.6. 

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