Furan chlorination

Chem. Descrip. Methyl methacrylate/modified PVC-based polymer Uses Heat-sealing raw material for pkg. of foods and pharmaceuticals adhesive/bonding agent for finishing PVC leatherette and film binder in printing inks and spray paints for PVC, ABS, PS coatings and films Properties Bead in powd. form sol. in ethyl acetate, MEK, acetone, cyclohexanone, butyl acetate, butyl glycol acetate, aromatics, tetrahydro-furan, chlorinated hydrocarbons insol. in naphtha and alcohols dens. 1.36 g/cm reduced vise. 45-55 em /g (20 C)... 

The proposed mechanism by which chlorinated dioxins and furans form has shifted from one of incomplete destmction of the waste to one of low temperature, downstream formation on fly ash particles (33). Two mechanisms are proposed, a de novo synthesis, in which PCDD and PCDF are formed from organic carbon sources and Cl in the presence of metal catalysts, and a more direct synthesis from chlorinated organic precursors, again involving heterogeneous catalysis. Bench-scale tests suggest that the optimum temperature for PCDD and PCDF formation in the presence of fly ash is roughly 300°C. 

Z-Furan. 3-(5-Nitro-2-furanyl)-2-propenamide, is prepared by condensation of 5-nitro-2-furancarboxaldehyde diacetate with malonic ester followed by PCl chlorination and amination (29). The product was marketed in Japan as a food preservative. 

Furan reacts vigorously with chlorine and bromine at room temperature to give poly-halogenated products. Low temperature (-40 °C) reaction of furan with chlorine in dichloromethane yields mainly 2-chlorofuran and reaction of furan with dioxane dibromide at 0 °C affords 2-bromofuran in good yield. 2-Iodofuran is obtained by treatment of 2-furoic acid with iodine and potassium iodide in aqueous sodium hydroxide. 

Halogens react with benzo[6]furan by an addition-elimination mechanism to give 2- and 3-substituted products (76JCS(P2)266). Treatment of benzo[6]thiophene with chlorine or bromine in acetic acid gives predominantly 3-substituted products (71JCS(B)79). 2,2,3,3,4,5,6,7-Octachloro-2,3-dihydrobenzothiophene is obtained when benzo[6]thio-phene is treated with chlorine in the presence of 1 mole of iodine (80JOC2l5l). 

Furane resins are superior to polyesters and epoxies for resistance to ketones, chlorinated solvents and carbon disulfide. However, as they are... 

Zone 2 acetal, ABS, chlorinated polyether, ethyl cellulose, ethylene-vinyl acetate copolymer, furan, ionomer, phe-... 

Aromatic bromine compounds can be formed and transformed during various thermal processes, like aromatic chlorine compounds (ref. 22). Brominated dibenzodioxins and -furans and mixed brominated/chlorinated compounds have been detected in trace levels in the fly ash of a municipal waste incinerator (ref. 23).Chlorine is generally abundant compared to the bromine of typical municipal waste the chlorine vs. bromine ratio is in the range of 250 1. 

These results show the fate of aromatic bromine compounds during municipal waste incineration bromine is exchanged by chlorine on the surface of fly ash at the electrostatic precipitator at 250-3(X)°C. But the toxic potential at brominated dibenzodioxins and furans is not reduced by these transformations. The increase of PCDD/F concentration in MWI by adding bromine compounds has been pointed out by Lahl and coworkers (ref. 26). 

Concern has been expressed about the possible formation of dioxins and furans. However, measurements during experiments indicated that the emissions of dioxins and furans were not significantly elevated. Dioxin emissions with or without plastic input appeared to be about a factor of 100 below the standard of 0.1 ng/Nm TEQ TCCD (toxicity equivalent in relation to the toxic dioxin TCCD) (a.7). This might be due to the benefit of the strongly reducing atmosphere and the high temperature of 2100 °C. In total, until now the conclusion has been that at current PVC levels in MSW, pretreatment for chlorine removal is unnecessary. 

Koester CJ, RA Hites (1992) Wet and dry deposition of chlorinated dioxins and furans. Environ Sci Technol 26 1375-1382. 

Emissions from hazardous waste combustors are regulated under two statutory authorities RCRA and the CAA. The MACT standards set emission limitations for dioxins, furans, metals, particulate matter, total chlorine, hydrocarbons/carbon monoxide, and destruction and removal efficiency (DRE) for organics. Once a facility has demonstrated compliance with the MACT standards by conducting its comprehensive performance test (CPT) and submitting its notification of compliance (NOC), it is no longer subject to the RCRA emission requirements with a few exceptions. RCRA-permitted facilities, however, must continue to comply with their permitted emissions requirements until they obtain modifications to remove any duplicative emissions conditions from their RCRA... 

The pulp and paper industry is the largest industrial process water user in the U.S.5 In 2000, a typical pulp and paper mill used between 15,140 and 45,420 L (4000 to 12,000 gal) of water per ton of pulp produced. 1 2 3 4 General water pollution concerns for pulp and paper mills are effluent solids, biochemical oxygen demand (BOD), and color. Toxicity concerns historically occurred from the potential presence of chlorinated organic compounds such as dioxins, furans, and others (collectively referred to as adsorbable organic halides, or AOX) in wastewaters after the chlorination/ extraction sequence. With the substitution of chlorine dioxide for chlorine, discharges of the chlorinated compounds have decreased dramatically. 

Dioxin and furan. During the late 1980s, bleaching with chlorine and hypochlorite were discovered to be a source of dioxin and furan. Although the use of chlorine dioxide (ClOj) bleaching minimizes the formation of chlorinated pollutants, measurable quantities of... 

On April 19, 1996, U.S. EPA published a proposed rule, called the MACT rule, under the joint authority of the RCRA and the CAA, to upgrade the emission standards for HWCs. Specifically, this rule will affect incinerators, cement kilns, and lightweight aggregate kilns. It proposes emission standards for dioxins, furans, mercury, cadmium, lead, PM, hydrochloric acid, chlorine,... 

The combustors affected by this rule detoxify or recover energy from hazardous waste and include incinerators, cement kilns, lightweight aggregate kilns, boilers and process heaters, and hydrochloric acid production furnaces. U.S. EPA estimates that 145 facilities operate 265 devices that burn hazardous waste. These technology-based standards reduce emissions of hazardous pollutants, including lead, mercury, arsenic, dioxin and furans, and HC1 and chlorine gas. In addition, emissions of PM are also reduced. 

The review by Barrett (Ref. 127) documents synthetic application of hetero-substituted nitroalkenes (see also Chapter 4). 1-Chloro-l-nitroalkenes are readily obtained either by the Henry reaction of chloronitromethane with aldehydes or chlorination of l-nitroalkenes. Dauzonne and coworkers have used 1-chloro-l-nitroalkenes for construction of dihydrobenzo-furan or dihydrobenzopyran frameworks. (Eq. 5.83).133... 

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