Energy cost savings

The preferred route to higher purity naphthalene, either coal-tar or petroleum, is crystallisation. This process has demonstrated significant energy cost savings and yield improvements. There are several commercial processes available Sulser-MWB, Brodie type. Bets, and Recochem (37). 

Optimal economic insulation thickness may be determined Iw various methods. Two of these are the minimum-total-cost method and the incremental-cost method (or marginal-cost method). The minimum-total-cost method involves the actual calculations of lost energy and insulation costs for each insulation thickness. The thickness producing the lowest total cost is the optimal economic solution. The optimum thickness is determined to be the point where the last dollar invested in insulation results in exactly 1 in energy-cost savings ( ETI— Economic Thickness for Industrial Insulation, Conservation Pap. 46, Federal Energy Administration, August 1976). The incremental-cost method provides a simplified and direcl solution for the least-cost thickness. 

This method of comparing the initial capital cost against the annual energy/cost savings is relatively easy. Unfortunately, it does not take into account certain factors such as ... 

For long-term hydrolytic stability and exceptional water separation, polyalphaolefins are the preferred rotary compressor lubricants. The energy cost savings... 

No structural changes required. Significant energy cost savings. 

Energy cost savings in comparison to normal operation (%) 30 40 60... 

As can be seen in Figure 1 present cost of losses (C PVF) in the future is stabilized after some time, the interest rate has a large impact on the saturation rate. This means that the present value of energy saved during the hoist operation depends on the interest rate and on the number of years used in the cost saving calculation. The difference in the future energy cost savings with an interest rate of 4% or 10% over 20 years is a factor of 1.6. 

Energy cost savings could be 2.9 MM/year assuming fuel priee at 6/MMBtu and operating time of 360 days/year. 

The capital investment required to implement reduced energy consumption in existing evaporators varies considerably. In most cases, the energy cost savings will increase directly with the amount of capital invested. In some cases, such as improved procedures for operation and maintenance of an existing evaporator, sizable cost and energy reductions can be achieved at low capital costs with very little hardware modification. 

I The potential energy cost savings achieved by switching to a heat-pump system depends both on the energy performance of the new system and the fuel source used by the system currently in place. 

Substantial energy cost savings across the whole of the process industries can result if the performance of heat exchangers is improved. One technique which is already used to improve heat exchanger performance (and indeed process heat transfer in general) is enhancement. In fact heat transfer enhancement is the most common way of increasing the heat transfer in equipment, typified by fins on most air-cooled equipment. Of particular relevance is the fact that enhancement, be it of heat and/or mass transfer, is critical to many other PI items of plant. 

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