Energy and Costs

The annual energy consumption by microscreens is shown in Fig. 2 (9). Electrical energy requirements include backwash water pumping and screen drive (10). 

The microscreens construction and operation and maintenance costs (1979 dollars, Utilities Index = 257.20) are illustrated in Figs. 3 and 4, respectively (9). To obtain the values in terms of the present 2004 US dollars, using the Cost Index for Utilities (Appendix A), multiply the costs by a factor of 506.13/257.20 = 1.97 (20). The costs are based on the following assumptions  

Construction costs include tanks, drums, screens, backwash equipment, drive motors, and building. 

Instrumentation for automatic operation is included. The design basis is as follows  

Sidsmerged Screen Area, ft Fig. 2. Microscreens energy consnmption (Sonrce US EPA). 

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The fineness to which a material is ground has a marked effect on its production rate. Figure 20-8 is an example showing how the capacity decreases and the specific energy and cost increase as the product is ground finer. 

One of the major problems facing our civilization is the availability of pure water. The largest source of water located near many cities is the ocean, but the ocean is filled with large amounts of dissolved salts. To recover water from the sea by any of the conventional distillation processes is to date extremely wasteful of energy and costly. However in... 

Low-temperature solid-state synthesis is preferred in most cases, where appropriate, for obvious reasons such as energy and cost economy and process safety or for critical concerns regarding the accessibility of compounds that are stable only at low temperatures or non-equilibrium phases, i.e., compounds thermodynamically unstable with respect to the obtained phase (e.g., a ternary instead of binary phase). The use of low-temperature eutectics as solvents for the reactants, hydrothermal growth... 

Andraos, J. (2005) On Using Tree Analysis to Quantify the Material, Input Energy, and Cost Throughput Efficiencies of Simple and Complex Synthesis Plans and Networks Towards a Blueprint for Quantitative Total Synthesis and Green Chemistry. Organic Process Research and Development, 10, 212-240. 

TABLE 4. Individual measures and measure sets with energy and cost comparisons to the base case... 

For the energy- and cost-calculation of the HPE-process a program has been developed, allowing the determination of the various cycle processes under selected conditions for extraction and separation. In principle, the cycle is either in the pump- or in the compressormode. 

The by-products, such as isomaltose, have to be removed chromatographically, which is energy- and cost-intensive. Protein engineering focuses on increasing the glucose yield (affecting enzyme selectivity) and enzyme thermostability. 

Case SP Shell International Chemicals—PDC Bulk Chemical Process Design (37). This new process design consists of a multifunctional reactor, which largely combines reaction, heat exchange, and component separation in one piece of equipment. Data on energy and cost element reductions are provided. 

To start the process, the engineer defines as accurately as possible the inputs, outputs and energy and cost objective functions. Then the reference environments, both physical and economical are defined. These are not necessarily straightforward steps, as for example when dealing with high rates of... 

This study shows the possibilities and specific feature of IR-pyrolysis for the formation of nanostructured carbon. In such way PAN, thermal transformations of which have been studied in detail [8-11], was chosen as the precursor for preparation of nanostructured carbon materials by carbonization of PAN and its composites with gadolinium chloride under non-coherent IR radiation. Specific action of IR-radiation on vibrational energy of PAN bands macromolecules allows one to decrease extremely time treatment and as a result to make simple, low energy and cost-effective pyrolitic method. 

By using disperse dye liquid concentrates which have thermofixation of 95% or greater (26), polyester fabrics can be foam-dyed at very lew wet pick-ups (e.g., 15-20% for medium-deep shades) without need for afterwashing. The resultant annualized per-line energy and cost savings are estimated, using Wygand s data (24), to be 30 x 10 BIU and 75,000, respectively. 

Table VIII. Reduction in Materials, Energy, and Cost by Reuse of Dyebaths in Carpet Dyeing...

The MPG process preheats a gaseous feedstock with hot raw gas and an optional fired preheater. Preheat level and installation of the fired heater are determined by energy and cost optimization, which is based on the relative values of feed, fuel gas, and oxygen. Feed gas and oxygen enter the reactor with a minor amount of steam via the gas burner. Gasification occurs in a refractory-lined reactor at temperatures between 1200 and 1400°C.179... 

The Nd-Fe-B magnets are based on the intermetallic compound of the formula Nd2Fei4B. The interest in these magnets is due to the fact they are stronger than other materials and of low cost. The magnetic energies and costs of the most common magnetic materials as of 1986 are presented in Table 12.12. 

In terrestrial ecosystems, afforestation and reforestation in tropical and temperate zones are effective for CO fixation from the viewpoint of energy and cost efficiency. 

Introduction Microscreening Process Design Criteria Backwashing Design oe Microscreens Energy and Costs Design Example Nomenclature Reeerences Appendix... 

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