Recycling objective

Even if the percentage of plastics waste used as a filler cannot be high, its common use may absorb sizable amounts of wastes. As an example, in Italy, a blending of 10% of mixed plastics waste with non-food thermoplastics, excluding those for film manufacturing, could utilize 172,000 t/years, that is about 75% of all the plastic bottles manufactured every year in our country. It should be thus possible to fully satisfy the recycling objectives of the Italian law that requires a 40% recycling in 1992. 

To assist in the deposition of these larger droplets, nebulizer inlet systems frequently incorporate a spray chamber sited immediately after the nebulizer and before the desolvation chamber. Any liquid deposited in the spray chamber is wasted analyte solution, which can be run off to waste or recycled. A nebulizer inlet may consist of (a) only a nebulizer, (b) a nebulizer and a spray chamber, or (c) a nebulizer, a spray chamber, and a desolvation chamber. Whichever arrangement is used, the object is to transfer analyte to the plasma flame in as fine a particulate consistency as possible, with as high an efficiency as possible. 

There have been a number of cell designs tested for this reaction. Undivided cells using sodium bromide electrolyte have been tried (see, for example. Ref. 29). These have had electrode shapes for in-ceU propylene absorption into the electrolyte. The chief advantages of the electrochemical route to propylene oxide are elimination of the need for chlorine and lime, as well as avoidance of calcium chloride disposal (see Calcium compounds, calcium CHLORIDE Lime and limestone). An indirect electrochemical approach meeting these same objectives employs the chlorine produced at the anode of a membrane cell for preparing the propylene chlorohydrin external to the electrolysis system. The caustic made at the cathode is used to convert the chlorohydrin to propylene oxide, reforming a NaCl solution which is recycled. Attractive economics are claimed for this combined chlor-alkali electrolysis and propylene oxide manufacture (135). 

The choice of the appropriate azeotropic distillation method and the resulting flowsheet for the separation of a particular mixture are strong functions of the separation objective. For example, it may be desirable to recover all constituents of the original feed mixture as pure components, or only some as pure components and some as azeotropic mixtures suitable for recycle. Not every objective may be obtainable by azeotropic distillation for a given mixture and portfolio of candidate entrainers. 

Resource Recovery Act, 1970 The Solid Waste Disposal Act of 1965 was amended by Public Law 95-512, the Resources Recovery Ac4 of 1970. This act directed that the emphasis of the national solid-waste-management program should be shitted from disposal as its pri-maiy objective to that of recycling and reuse of recoverable materials in sohd wastes or the conversion of wastes to energy. 

The first objective of the antisurge control system is to protect the compressor. This can be accomplished for some disturbances by using the PI algorithm with a large value of bj. However, it is also necessary to maximize the region in which the compressor can operate with the recycle valve closed. This increases the efficiency of the compressor at lower throughputs. Steady-state operation with recycle is extremely inefficient. Therefore, from this perspective, small values of bj are highly desirable. 

In precoating, the prime objective is to prevent the filter medium from fouling. The volume of initial precoat normally applied should be 25 to 50 times greater than that necessary to fill the filter and connecting lines. This amounts to about 5-10 lb/100 fF of filter area, which typically results in a 1/16-in. to 1/8-in. precoat layer over the outer surface of the filter medium. An exception to this rule is in the precoating of continuous rotary drum filters where a 2-in. to 4-in. cake is deposited before filtration. The recommended application method is to mix the precoat material with clear liquor (which may consist of a portion of the filtrate). This mixture should be recycled until all the precoat has been deposited onto the filter medium. The... 

Furthermore, for quality and operability objectives the plant does not wish to recycle the AN product stream (top of distillation column), the feed to the distillation column and the feed to the decanter. 

The objective of this case study is to determine the target for minimizing the total load (flowrate x composition) of CE discharged in terminal wastewater of the plant using segregation, mixing, and recycle strategies. 

The objective of this phase of the methanation system s operation is to determine space velocity requirements, recycle ratio, and analytical and control systems. 

In order to achieve this goal of a fully integrated process sequence, a concerted research and process development effort must take place. Present R D efforts are devoted to the development of cost-effective pyrochemical processes for the recycle of plutonium in residues. Future efforts will be aimed at the recycle of reagents in each individual process. The objectives of the recycle are to produce plutonium metal which can be further purified, and to generate small volumes of residues which can be discarded or recycled. 

Details are given of the enzymatic transformation of polycaprolactone into repolymerisable oligomers in supercritical carbon dioxide. The object was to establish a sustainable chemical recycling system for polycaprolactone. 14 refs. 

Material recycling is the objective for every material, but at some point reuse or collection, separation and further recycling will no longer yield a useful product. The so-called plastic waste still contains a high calorific value which can be recovered to produce heat or electricity. Even better it may be possible to recover the chemical feedstock originally manufactured from oil. These two possibilities are reviewed. 

The objectives of this study were to compare the yields of cold-pressed essential oil, water consumption, material balance and efficiency of the process in a typical citrus peel oil recovery plant with and without recycling system. The different emulsions and aqueous discharges from these processes were also characterized. 

Our case studies prove that optimization objectives generally followed in synthesis design and during scale up show a high potential for increasing resource efficiency. These objectives are, for example, increases of yield and the recycling efficiency of solvents and auxiliary materials. 

---