Recycling requirements

Plastics recycling has become more and more common for two different reasons [4, 5] the first is driven by cost, which requires the reprocessing of faulty parts and scrap from moulding methods. The second is environmental, which is crucial in the case of commodity plastics due to the large production volume. 

Successful material recycling is dependent upon the purity and uniformity of the plastics waste. The properties of the recycled material depend upon the history of the synthesised polymer, the primary processing and application, and finally the recovery methods/equipment. Sorted, single polymer waste exhibiting low 

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In the case of a liquid recycle, the cost of this pressure increase is usually small. Pumps usually have low capital and operating costs relative to other plant items. On the other hand, to increase the pressure of material in the vapor phase for recycle requires a compressor. Compressors tend to have a high capital cost and large power requirements giving higher operating costs. 

Cascade with recycle required to obtain one (relatively) pure permeate and enriched retentate. 

The recycle requirements of products in different apphcations can vaiy substantially depending upon the scale of operation, the ease of diying, and the finished-product specification. The location of reintroduction of undried material back into the diying medium has a significant impact upon the dryer performance and final-product characteristics. 

The possible advantages of this system over the equilibrium-limited reactor system are smaller catalyst beds, lower gas recycle requirements, and lower capital requirements. The possible disadvantages of this system are (a) practically no turn-down since any turn-down would be equivalent to decreased space velocities, closer approach to equilibrium, and higher temperature rises (b) maldistribution of gases across the bed would give rise to excessive temperature rises in zones of low flow and (c) considerably shortened catalyst life because of possible high local or zonal temperature and, concurrently, greater chances for carbon laydown. 

If the reactor conversion is changed so as to optimize its value, then not only is the reactor affected in size and performance but also the separation system, since it now has a different separation task. The size of the recycle will also change. If the recycle requires a compressor, then the capital and operating costs of the recycle compressor will change. In addition, the heating and cooling duties associated with the reactor and the separation and recycle system change. 

Table 4.2 Processing options and their influence on PET recycling requirements c, critical aspect, where requirement is not or only partially fulfilled...

Cofactor recycling required required not required not required... 

More curved the boundary, less recycle required (generally less favorable for minimum boiling azeotropes because of large overhead recycles). 

The more thoroughly a metal finisher understands the chemistry of his waste streams, the better able he is to assess their potentials for reuse as raw materials, or in other applications. Successful recycling requires an attitudinal change on the part of management and plant staff, to view their waste streams as resources, rather than as something to be thrown away. 

In this examination, the cathode recycle case will have no recuperator and the recuperator case will have no cathode recycle. However, it is quite possible that a hybrid system could use both. The anode exhaust is combusted at the turbine inlet in all cases. This could be done in other locations, such as the recycle loop, which would reduce the recycle required. It is apparent that a number of other configurations could be imagined (such as intercooling) however, each will likely be a modification of one of the base configurations given here. 

Also, the operation with off-cut recycling requires lower energy consumption due to shorter batch time. 

Table 9-1. Major constraints on the recycling of postconsumer plastics. Successful recycling requires Recycling is not suitable for ...

Furthermore, the second law of thermodynamics (disorder is the preferred state) implies that the separation (creating order) of plastic materials from a mixture of plastics must involve supplying heat and work. Recycling plastics is, by nature, a costly business and in the extreme case, total recycling requires infinite work and heat. 

The concentration of plutonium in the filtrate, which is a measure of the completeness of precipitation and so the amount of plutonium recycle required, was determined coulometrical 1y. 

Fuel Recycle Requirements. We asstime that the final product returned for fuel fabrication and recycle is a mixed uranium-plutonium dioxide material, partially decontaminated from fission products. The questions of fissile material enrichment, radiation levels, and required handling facilities are not addressed. 

About 8.5% of glass containers used in 1986 wa recycled [11], Since only about 20% of all silica-based glass goes into other products (flat glass, fiba glass, etc.), the 8.5% figure is rather impressive. Most recyclers request (and most municipalities that recycle require) that glass be separated into clear and colored portions. 

The COBAT databank allows monitoring of the flow of spent batteries to the recycling plants. In this way, it is possible to meet the recyclers requirements and to optimise the number of voyages to reduce the risk of environmental damage. 

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