Methods for the Economic Evaluation

Drummond MR, O Brien B, Sroddarr GL, Torrance GW (1997). Methods for the Economic Evaluation of Health Care Programmes, 2nd edn. Oxford Oxford Medical Publications. 

As probes must be manufactured individually for each different tube type, the probe development is an important factor for the economic use of the method. The classical procedure of probe development is a combination of experience and experiment. The new probe design is based on the experience with already manufactured probes. For an evaluation of the new design the probe must be manufactured. If the probe design is complicated, for example due to dual exciter coil arrangement or segmented differential detector coil systems, the costs of the development can be very high. Therefore a method for the pre-calculation of the probe performance is extremely useful. 

Because the physical characteristics of the particulate solids both affect, and are affected by each unit operation, there exists an interaction between them. The study of particulate systems thus provides methods for synthesizing and evaluating economically optimum process configurations. 

Enamide hydrogenations have become a routine test reaction for evaluation of the effectiveness of new chiral Hgands [5,11,20,56,59,104]. In addition to being a test reaction, it stands as one of the most powerful and economic methods for the production of enantiomerically pure a-amino acid derivatives. Our group... 

Frangopoulos, C.A. and Caralis Y.C., 1997, A method for taking into account environmental impacts in the economic evaluation of energy systems, Energy Comers. Mgmt. 38 1751-1763. 

Drzyzga et al. [411] conducted experiments to evaluate the levels of incorporation and transformation of TNT and metabolites into the organic soil matrix of anaerobic and sequential anaerobic-aerobic treated soil/molasses mixtures. They proposed a two-step treatment process (i.e., anaerobic-aerobic bioremediation process) with some special procedures during the anaerobic and the aerobic treatment phases. The transformation of TNT at the end of the experiments was above 95% and 97% after anaerobic and sequential anaerobic-aerobic treatment, respectively. This technique is considered the most promising method for effective, economic, and ecologically acceptable disposal of TNT from contaminated soils by means of immobilization (e.g., humification) of this xenobiotic. 

All eleven references in this category relate directly to Section 6.1, the Economic Evaluation of this project. They contain capital costing methods, cost correlations, typical plant and equipment costs, and economic indicators to account for cost changes with time. 

The economic evaluation is an important and integral part of the overall feasibility study of the project. First, a capital cost estimate is obtained using two estimation techniques. The ratio method and factorial cost estimation techniques are used to determine separate capital cost estimates for the proposed 280 tonne/day plant. Finally an investigation into the expected return on investment from this project is performed. 

In the United States crop losses due to pests are about 30% or 20 billion annually, despite the use of pesticides and other current control methods (3). Ware (3) addresses the question of "what would the losses be without the use of insecticides " Studies conducted in 1976-1978 compared the yields from test plots, where insecticides were used to control insects, to adjacent plots in which the insects were allowed to feed and multiply uncontrolled. Summary data from this study are shown in Table IV. These data suggested that, on the average, for the crops evaluated, half of the crops are lost to insects. Even with insecticides, 10% of the crop is lost. The issue, however, is what rate of return can a farmer expect from the use of insecticides on these crops The data suggested an average increased yield of 36%. Pimentel and Levitan (4) concluded that in economic terms, for the 3 billion invested in the United States in controlling pests through the use of pesticides, about 12 billion are returned in increased return on investment. 

The role of process development is to balance the timeline and material requirements of the project with the need to develop a commercially viable method for the preparation of the drug candidate. This stage of the drug development process will concentrate on such issues as (l)synthetic strategy, improvement of individual reaction yields, (3) identification and use of commercially available raw materials and reagents, (4)evaluationof alternative solvent systems, (5) compatibility of process conditions with existing manufaetur-ing assets, identification and quantification of potential process safety hazards, (7) simplification of purification methods, (8) evaluation of process waste streams, and (9) the improvement of the overall process economics. 

Each method of fractionation requires different operating techniques and different equipment types, sizes and configurations. Two-stage extraction requires longer total extraction cycles, and possibly, parallel separator vessels to collect each fraction Individually, and/or addition of humidification vessels. Multiple stage separation requires additional separator vessels with required heaters and pressure controls. In all three cases, the products can be used as separate fractions, or In various combinations to suit the user needs and marketplace considerations. Choice of fractionation and standardization methods for a commercial-scale SCFCO2 plant Is dependent on results of the economic evaluation of all technically feasible process design alternatives. 

The economic evaluation studies are based on normative criteria, independent of subjective opinions, which indicate preferences in any course of action. Every alternative is independent of the other ones and the measure of the economic preferences is made separately. Renkema and Berghout [10] distinguish four basic approaches to evaluate investment alternatives the financial approach, the multicriteria approach, the ratio approach, and the portfolio approach. Methods from the financial approach are usually recommended for the evaluation and selection of investment alternatives. Often used financial approach methods are the payback period (PP) method, the internal rate of return (IRR) method, and the NPV method. The latter is used to evaluate this project. 

Recently, CE coupled with Ru(bpy)3 ECL for highly sensitive detection of metformin hydrochloride (MH) derivatized with acetaldehyde is reported. The precolumn derivatization of MH with acetaldehyde was performed in phosphate buffer solution (0.3 mol L pH 7.5) at room temperature for 120 min. The factors affecting this method of analysis, e.g., acetaldehyde concentration, buffer pH, electrokinetic voltage and injection time were examined and under optimization of these conditions, the MH ECL detection sensitivity was more than 120 times that without derivatization. The detection of 0.3 ng mL with S/N = 3 was attained. The proposed method is simple, economical, and sensitive and is used for the determination of MH in urine [42]. A method combining CE with Ru(bpy)3 " ECL detection that can be applied to amine-containing clinical species was developed, and the performance of CE-ECL as a quantitative method for the determination of sulpiride in human plasma or urine was evaluated [43]. 

One economic evaluation method that is used is based on the internal return rate (IRR), which is considered suitable for an initial estimate of economic feasibility of industrial processes (Di Lucdo et al, 2002). This method is based on evaluating the discount rate that causes the present value of the cash flow, projected for the plant life, to be equal to the invested capital. The basic idea for the IRR evaluation is to obtain a single value that synthesizes the merits of the project for its lifetime. This value is not determined by market interest rates, and hence it is labelled internal return rate. The IRR is intrinsic to the project and does not depend on anything but the project cash flow. 

Finally, a new concern has focused the attention of many researchers— water consumption. The main problem with water consumption is that, in general, the cost is low and thus the economic evaluation does not provide water consumption minimization apart from the sequential approach consisting of the development of water networks for the treatment and reuse of water after process design [24]. Currently, a simultaneous process design with heat and water integration is being developed based on the targeting methods [25]. 

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