Electricity, saving

Solar water heaters (SWHs) are relatively expensive to install ( 500— 2100), although the initial investment can be recovered through future electricity savings [1], For many families in rural areas, the purchase of a solar lighting set, even for lighting service only, is so hard that a... 

Year Electricity savings ( ) Natural gas ( ) Maintenance ( ) Savings ( )... 

Cost of both PHE and power required for circulation pumps. Steam/fuel/electricity saved when hot water becomes available as above. 

Table 7.2 compares the energy cost of an RTO, an RCO and a catalytic oxidation unit. RCO has the lowest operating cost among these technologies. Relative to an RTO unit, the fuel cost for RCO is about 45 % lower. Additionally, there are electrical savings of 20% due to a lower pressure drop across the bed. For a 60,000 SCFM unit, a yearly net saving of 75,000 can be realized by converting RTO to RCO. 

One application for the RCO catalyst which will provide a substantial cost reduction is the RTO to RCO conversion. One alternative is to put a layer of proprietary precious metal catalyst on top of the existing bed in the regenerative chamber of the RTO. This will reduce the operating temperature required to oxidize the VOCs to about 450°C. Another alternative is to remove some ceramic saddles before installing the RCO catalyst on top of the catalyst bed. These approaches can be made to meet the customer s needs for maximizing fuel or electrical savings. 

Figure 15.5 A simple modification reduces the load on the heat pump, saving electricity. (From Smith and Linnhoff, Trans. IChemE, ChERD, 66 195, 1988 reproduced by permission of the Institution of Chemical Engineers.)...

Induction heating equipment installations can require significant investment in electric power components as well as the work handling equipment made necessary by the process. These costs can be offset by savings in plant space, reduction in metal loss, precise control of product temperature, and reduced in-process inventory. A typical continuous induction heating line consumes about 360 kW h/t heating carbon steel bars to 1230°C. 

Explosion-welded constmction has equivalent or better properties than the more compHcated riveted systems. Peripheral benefits include weight savings and perfect electrical grounding. In addition to lower initial installation costs, the welded system requires tittle or no maintenance and, therefore minimizes life-cycle costs. Applications of stmctural transition joints include aluminum superstmctures that are welded to decks of naval vessels and commercial ships as illustrated in Figure 11. 

Many units have waste heat recovery systems that generate low pressure steam from reaction heat. Such steam is often employed to drive adsorption refrigeration units to cool the reactor feed stream and to increase polymer conversion per pass, an energy-saving process that reduces the demand for electrical power. 

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