Waste-Minimized Bromination

The reaction efficiency depends on temperature, mole ratio of reagents, and intensity of the visible light. These parameters were easily managed. Moreover, the atomic utihzation of bromine is greatly increased. In this method, l IBr and water are the reagent and by-product respectively, providing a process that is eco-friendly and cost effective (48% aqueous HBr is inexpensive). 

---

For the organic contaminants, the required bromine product quality wilt also be site specific. If the catalytic oxidation unit is dedicated to a single bromination process, phase separation and drying may be the only purification required. Contaminants in the recovered bromine which are either the starting materials or products of the original bromination reaction should not present a problem if present in bromine recycled to the bromination reactor. In this case, the catalytic reactor would be operated to minimize the formation of undesirable brominated byproducts. For example, if phenol is present in the waste HBr from a tribromo-phenol manufacturing process, minor tribromophenol contamination of the bromine recycled to the reactor should not be a problem. Similarly, fluorobenzene in bromine recycled to a fluorobenzene bromination process should not present a problem. 

Any post-consumer plastic stream will contain some halogens in the form of polyvinyl chloride, polyvinylidene chloride, brominated flame retardants, halogenated additives, food waste, or salt. Therefore, two issues must be considered. First, the gas stream resulting from the depolymerization of plastics must be scrubbed to remove any halogenated gases to satisfy emissions controls. Second, halogens in the liquid product must be minimized to increase its value and marketability. Therefore the Conrad process has been developed. It is a robust process unit that can accommodate a variable feedstream and produce a consistent product, free of nonhydrocarbon impurities by low feed preparation costs. 

The environmental problems associated with COBr are minimal when compared with phosgene, but there is a report that it may be a by-product from tribromomethane oxidation in waste water treatment [1702], and it has been identified as a minor impurity in commercial bromine produced by the electrolysis of brine [865], and a possible minor impurity in... 

---