Recovery values

Table 5 Example for an adequate presentation of blank values, recovery and reproducibility for...

Sulfur values, recovery as SO2, 23 619 Sulfur vapor, molecular composition of, 23 565... 

We can convert all types of classical control chart (X-chart, blank value, recovery, range control chart etc.) into target control charts. 

Two of the most common methods of determining accuracy are by comparing the proposed test procedure to a second test procedure whose accuracy is known and the recovery of drug above and below the range of use. Average recovery of the drug should be 98-102% of the theoretical value. Recoveries can be determined by either external or internal standard methods. 

Line 13 gives the annual cash flows for each of the operating years with the zero-year column giving only the total capital investment. In line 16, the present value of the annual cash flows to the project is obtained by summing the individual present values for each year of operation including the present value of the working-capital and salvage-value recovery at the end of the service life. Line 17 merely applies the definition of net present worth as used in this text as the difference between the total present value of the annual cash flows to the project and the initial required investment. 

While all pyrolysis oil production reactor systems produce similar materials, each reactor produces a unique compound slate. The first decision, especially for a potential chemical or fuel producer, rather than a reactor developer, is to determine what products to make and which reactor system to use. The operating parameters of any reactor system designed to produce pyrolysis oil, especially temperature, can be altered to change the pyrolysis oil product composition and yield. Different feedstocks will produce different pyrolysis oil compositions and by-products, e.g. amorphous silica from rice hulls or rice straw, fatty acids from pine. Finally, feedstock pretreatment and/or catalysis, or reactor-bed catalysis can be used to improve specific product yields (7). Reactor system developers need to examine what they can produce and make this information available to chemical manufacturers and suppliers/owners of biomass feedstocks. This assumes that analysis of die entire liquid product from thermal conversion can be made, including quantitative analysis for any compounds that are being considered for recoveiy. Physical characterization - pH, viscosity, solids content, etc.is also needed. However, what can be produced is of no value, if it cannot be recovered or used economically. This involves examining the trade-offs between yield and current commercial value, recovery costs, and potential commercial value,... 

At end-of-life, value recovery is of the utmost importance. The highest value is obtained when the product is used for yet another service with little or no additional expenditure of resources. For example, a Pentium I personal computer considered outdated in the United States may be shipped to a less developed economy to provide simple services such as e-mail access. The worst end use would be casting the device into a landfill. Figure 5.2 shows the end-of-life values recovered by different... 

What energy sources are used in its creation, distribution, use, and value recovery processes ... 

Figure 5.6 illustrates a value recovery hierarchy that can be used to inform decisions about material cycling strategies. 

Figure 5.6. A value recovery hierarchy. (Source GreenBlue, 2004).

The recoveries of the methods were determined by spiking the sewage sludge with known of each of the PAHs at three different levels and comparing the expected and measured values. Recoveries ranged from ca. 60 to 107%. 

Metal Value Recovery from Metal Hydroxide Sludges Removal of Iron and Recovery of Chromium... 

Fig. 6.85 Scheme of the electrochemical pH value recovery in concrete, (according to [350]) 1—electrolyte, 2—anodic net, 3—reinforcing bar, 4—direct current source... 

Recycling is an alternative for the management of an end-of-use product. Recycling is the process of material value recovery and is often... 

Accuracy refers to the closeness of agreement between a measured value and the reference or true value. Accuracy can be reported as %recovery, an estimation of the closeness of an observed (measured) result to its expected value. Recovery is expressed as a percent of the expected (theoretical or nominal) concentration ... 

Analyte Isotope Average Measured Cone (pg/L) Std. Dev. Rel.% Dif. High Purity Certified Value Recovery of Certified Value (%) Spike Level (pg/L) Average Spike Recovery (%) Std. Dev. of Spike Rec. Rel.% Dif. 

The major pitfall of chemical separations is the varying and unavoidable loss of material. Nonetheless, there are several ways of controlling the losses by calculating the chemical recoveries for the whole procedure. The amount of carrier can be determined in the measurement source at the end of separation and compared with the initial value. Recovery should be corrected for the presence of the element in the original sample. The amount of carrier can be determined by classical analytical methods, such as gravimetry or by nuclear techniques. In the case of short-lived nuclides, reactivation is an appropriate technique. 

A classic paradox exists at this stage of evolution. Should these collection centers be built and assume end-users will materialize or should the uses drive creation of the collection centers The role of cement kilns, where carpet may be used as an alternative derived fuel in large quantities, would be a catalyst for jump starting the collection infrastructure. Once this collection infrastructure is in place, material can be redirected into higher value recovery channels. The development of such models is currently underway. Figure 4.2 shows the mass flow of post consumer carpet at the end of 2003. 

Many fields of expertise are necessary for the understanding of problems involved in the value recovery from plastics waste, either as materials, chemicals or energy. For these reasons contributions are required from chemists, physicists, engineers as well as polymer and materials scientists. Due to the dimension of the subject, the participation of the environmental, legal and economic experts is also of paramount importance. 

Incineration of waste plastics and polymers, though still widely practiced in many countries, is presently not favoured due to the potential for toxic off-gases such as dioxins from the use of mixed polymer feedstocks, which include halogenated polymers such as poly(vinyl chloride). If this issue can be resolved, incineration and fuel value recovery from waste plastics becomes very attractive and probably the best disposal option. 

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