Investment heat recovery

Investment, Costs, and Prices for Barley and Malt. Estimated malthouse investment (1993) and costs for a new malthouse with annual capacity of 120,000 t are shown in Table 2. This malthouse is equipped with twelve 1,700-bushel steep tanks, eight 10,000-bushel germination compartments, and two double-deck kilns. The kilns are equipped with standard heat recovery units and indirect heat. 

This term is most familiar to people as the return on investment, or ROI. The ROI is defined as the interest rate that would result in a return on the invested capital equivalent to the project s return. For illustration, if we had an air abatement project where heat recovery was involved, and there was an overall ROI of 30 percent, that s financially equivalent to investing resources in the right stock and having its price go up 30 percent. This is called a Primitive ROI. ... 

Considering the energy and maintenance costs during the life cycle, the cheapest investment is not always the best. It may, for instance, be profitable to buy a ventilation unit with a heat recovery system, which may increase the unit investment by 50%. The return on the investment in such a case may be in excess of 20%. 

The investment costs should be estimated as accurately as possible. As can be seen in Fig. 16.2, a small difference in investment costs can influence the ranking of two heat recovery systems. 

The matter of different investment criteria for energy users versus regulated utilities is exemplified by comparison of the feedwater heater project (41) to the cement kiln heat recovery project referred to above. The utility chose to replace the de-... 

An alternative method of cooling metallurgical offgas is to pass it through sprays of water. Spray cooling avoids investment in waste heat recovery equipment but wastes the heat of the gas. It also generates acidic waste liquid that must be neutralized and treated for solids removal/recycle. 

Deodorization can be performed in different ways (continuous, semicontinuous, or batch). The selection of most appropriate deodorizer technology depends on many factors, such as the number of feedstock changes, heat recovery, investment, and operating costs. 

Continuous deodorizers are generally preferred for high-capacity plants with few stock changes. The main advantages are the moderate investment costs, the possibility of high heat recovery and the easy maintenance. 

The heat recovery heat exchanger is of flat-plate type Fig. 9). This construction was selected because of the low investment costs. Primary flow is moist, nearly saturated exhaust air from the drying silo, The secondary flow is outdoor air, which is used as combustion air and drying air. 

ESTIMATED INVESTMENT COSTS FOR LARGE MODULAR REFUSE INCINERATION SYSTEMS WITH HEAT RECOVERY... 

Consequently, the control of dioxin emissions from incinerators is one of the most urgent needs in environmental protection today [466, 516]. There are several treatment techniques presently in use, including the raising of the waste gas temperature to cause catalytic oxidative decomposition [516]. However, when the initial investment and mechanical complexity is taken into account, this method is not practicable for small-scale incinerators. A novel solution for this task would be to decompose dioxin and its derivatives at the dust filter using catal3dic oxidation, preferably below 473 K. This particular temperature is relevant since the waste gases are usually reduced to this temperature at the dust filter after efficient heat recovery. 

The development of a fluid bed reaction system which offers potential advantages in terms of yield, quality, heat recovery and lower investment cost has been completed and the system is now commercially available. 

The lower capital cost figures for various conservation measures (relative to the investment needed for new energy supplies) provide only a rough indication that such measures will yield attractive economic returns to the investor. Detailed payback calculations, similar to those discussed later for waste heat recovery equipment, are needed to establish economic feasibility in each specific case. 

Recent studies by Thermo Electron Corporation have shown that certain forms of waste heat utilization (e.g., recuperators or process steam boilers) provide a better return on investment than that obtainable from bottoming cycle generators. The optimum choice of heat recovery strategy depends, in part, upon the temperature of exhaust heat available. 

Whether heat recovery equipment should be applied to the exhaust of an industrial boiler depends on such factors as operational conditions, estimated maintenance, investments, payout time and fuel prices. The number of operating hours per year, boiler load, power consumption and fuel savings should be carefully balanced against costs. 

Figure 1-27. Fuel savings at MCR vs. investment increase for heat recovery equipment (1968 cost basis).

A prime advantage of the liquid-phase process is its substantially lower cost compared to vapor-phase processes investment is particularly low because a single, inexpensive main reactor chamber is used as compared to multiple-bed or tubular reactors used in vapor-phase processes. Quench gas and unreacted benzene recycles are not necessary, and better heat recovery generates both cyclohexane vapor for the finishing step and a greater amount of steam. These advantages result in lower investment and operating costs. 

Table 4.37 gives economic data for the example plants. For foundry G, the investment costs for a hot blast cupola with bag filter and extensive heat recovery are given. The operational costs for 1994 (after refurbishment of the melting shop) were 25 % lower than those for 1985, i.e. with the old melting furnace. For foundry H, investment costs for 1980 - 1981 are given. After refurbishment, the operational costs went down by 2 %/tonne of liquid iron. 

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