Aluminum, success with recycling

The ethyl aluminum dichloride-catalyzed synthesis of (7 )-(+)-cyclohex-3-enecarboxylic acid, using galvinoxyl to inhibit polymerization, has been successfully scaled up to the kilogram level.106 An improved synthesis of the chiral auxiliary, /V-acryloylbornane-10,2-sultam, was also described together with a recycle protocol. 

Experience with aluminum, glass and paper. There are lessons polymer recyclers can learn from older programs. Recycling of aluminum beverage cans is a true success. Over 50% of all cans were recycled in 1988, mostly back to the original application [9]. Several factors leading to this situation are worth considering for polymers. 

From an industry perspective, lead-acid batteries are an environmental success story — in most OECD countries, 96% of all battery lead is recycled [6]. Compared with the usual flagship recycled products, such as glass bottles at only 38%, aluminum cans at nearly 64%, and newsprint at about 68%, lead-acid batteries are the leaders in the field (see Fig. 16.2). ULAB have topped the list of the most highly recycled consumer products for over a decade. 

Acylation of anisole with A AN is carried out in a mixture of GALDEN SV 135, a suitable fluorous solvent, and chlorobenzene in the presence of hafnium tetra[bis(perfluorooctanesulfonyl)amide] (1% mol) at 70°C-120°C for 1 to 5 h, giving para-methoxyacetophenone in 80% yield and 100% selectivity. It is significant to underline that aluminum chloride gives the mentioned product in only 2% yield under the present mild reaction conditions. The catalyst can be very easily recycled by directly reusing the lower fluorous catalytic phase in the successive reaction with another mixture of reactants, affording the product more than three times without decrease in catalytic activity. The catalytic process can be applied to dimethoxybenzenes and mesitylene with both aliphatic and aromatic acyl chlorides and anhydrides (80%-97% yield). Benzoylation of toluene gives para-methylbenzophenone in 35% yield. 

For example, since 1987 Rhode Island has been successfully recycling MSW of all sorts in specific localities. The result has been the separating and selling of recycled paper, aluminum, glass, and plastics. Different procedures with their own auxiliary equipment are used to separate these materials, such as aluminum cans being separated from glass and plastic by eddy current equipment and conveyed to flatteners. Plastics separation involves granulating milk bottles (HOPE) and soda bottles (PET), which are also separable by color. At present 15 percent or some 60,(X)0 tons per year of Rhode Island s residential waste is disposed this way. 

In most processes recirculation of the stable feed hydrocarbon is maintained and the reactive olefin is fed into the recycling stream sometimes at several points. Thus, the concentration of olefin is always low and polymerization reactions are minimized. The alkylation reaction is favored by high pressures and low temperatures. However, in order to accomplish the reaction without catalysts, temperatures of 900 to 975 F are required.Polymerization also occurs rapidly at such temperatures, and hence the olefin concentration must be kept low. Thermal alkylation is conducted at 3,000 to 8,000 psig, whereas by means of catalysts such as sulfuric acid, boron fluoride, - aluminum chloride, double halides of alkali metals with aluminum, and hydrogen fluoride, pressures less than 500 psi and temperatures ranging from 450°F down to below zero may be employed. Sulfuric acid was widely used early in World War II as a catalyst in commercial installations, and a revival of interest has occurred since 1951. The process operates at 30 to 60 F for butenes and at substantially atmospheric pressure. The hydrofluoric acid process also proved during World War II to be a highly successful process, but only... 

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