Energy-consuming

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... 

The average daily incident solar radiation, or insolation, that strikes the earth s surface worldwide is about 220 W/m (1675 Btu/ft ). The annual insolation on 0.01% of the earth s surface is approximately equal to all energy consumed (ca 1992) by humans in one year, ie, 321 x 10 J (305 X 10 Btu). In the United States, the world s largest energy consumer, annual energy consumption is equivalent (1992) to the insolation on about 0.1 to 0.2% of U.S. total surface. 

Operation Energy consumed per dry wood produced, MT/t Total consumption, %... 

Net energy output gross energy output) X 100, ie, 100 ""Net energy output energy consumed, ie,... 

Processing costs include those for size reduction, size classification, minerals concentration and separations, soHd—Hquid separation (dewatering), materials handling and transportation, and tailings disposal. Size reduction, one of the most expensive unit operations in minerals processing, could account for as much as 50% of the total energy consumed. This cost varies considerably from deposit to deposit and quite often from one area of a deposit to another. Ore bodies are extremely heterogeneous and the associated minerals Hberation, complex. 

The energy consumed by a static mixer is given by P =. This energy is supplied by the pump used to create flow of the fluid through the... 

Container type Energy consumed in producing raw material, Gf /1 Number of containers per ton Energy consumed per 1 container, k ... 

Vinyl compares favorably to other packaging materials. In 1992, a lifecycle assessment comparison of specific packages made from glass, paperboard, paper, and selected plastics concluded that vinyl was the material that has the lowest production energy and carbon dioxide emissions, as well as the lowest fossil fuel and raw material requirements of the plastics studied (169). Vinyl saves more than 34 million Btu per 1000 pounds manufactured compared to the highest energy-consuming plastic (170). 

Because of the high temperatures and strong reducing conditions in the furnace a number of energy-consuming reactions take place. SiHca, the main impurity in the raw materials, may be partly volatilized as siHcon and later reoxidized in the cooler parts of the furnace. Some is reduced and combines with... 

Coal was the primary kiln fuel in 1989 as seen in Table 10. Energy from coal rose from 39 to 84% of the total energy required for cement production between 1972 and 1989. In the same time period, natural gas dropped to 9%, petroleum products to 1% of the total energy consumed. Waste fuels represented 5% of the energy consumed in 1989 cement production. 

Dtyer efficient is the fraction of total energy consumed which is used to heat and vaporize the Hquid. 

Table 1 is an estimate of energy usage by United States industry for 1988 (1). The chemical industry used 21% of the energy consumed by the U.S. industrial sector, and the other three related process industries, paper (qv), petroleum (qv), and primary metals, combined for an additional 50% of the industrial consumption. 

Grinding Efficiency The energy efficiency of a grinding operation is defined as the energy consumed compared with some ideal energy requirement. 

Advantages to Membrane Separation This subsertion covers the commercially important membrane applications. AU except electrodialysis are pressure driven. All except pervaporation involve no phase change. All tend to be inherently low-energy consumers in the-oiy if not in practice. They operate by a different mechanism than do other separation methods, so they have a unique profile of strengths and weaknesses. In some cases they provide unusual sharpness of separation, but in most cases they perform a separation at lower cost, provide more valuable products, and do so with fewer undesirable side effects than older separations methods. The membrane interposes a new phase between feed and product. It controls the transfer of mass between feed and product. It is a kinetic, not an equihbrium process. In a separation, a membrane will be selective because it passes some components much more rapidly than others. Many membranes are veiy selective. Membrane separations are often simpler than the alternatives. 

Decrea.sed energy consumption. As mentioned previously, methods of energy conservation are often interrelated and complementary to each other. Energy expenditures associated with the treatment and transport of waste are usually but not always reduced when the amount of waste generated is lessened, while at the same time the pollution associated with energy consumed by these activities is abated. 

Total energy consumed per year, considering 300 operating days/year... 

Energy consumed while operating at the reduced capacity for 25% duration = 0.25 x 720 000... 

Modern nitric acid plants are designed for energy self-sufficiency during normal operation. Except for the startup phase, process heat generated will equal energy consumed by the compressors. Moreover, in many cases surplus energy can be exported in the form of steam, for example. 

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