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PGO Processing with azeotropic rectification to extract naphthalene
Published in Vladimir Litvinenko, Topical Issues of Rational Use of Natural Resources 2019, 2019
Biphenyl is used as a precursor in the synthesis of polychlorinated biphenyls, as well as other compounds used as emulsifiers, insecticides and dyes. It is possible to extract about 50 tons of biphenyl per year from PGO liquid product.
Chlorinated Hydrocarbons
Published in Michael J. Kennish, Ecology of Estuaries: Anthropogenic Effects, 2019
Individual chlorobiphenyls are prepared by the phenylation or arylation of aromatic compounds. Industrial preparations have entailed the chlorination of biphenyl in the presence of a catalyst (e.g., iron filings or iron chloride).3 The complex mixture of chlorobiphenyls constituting the purified PCB product contains 18 to 79% chlorine.50
Current Use and Future Promise of Genetic Engineering
Published in Michael Hehenberger, Zhi Xia, Our Animal Connection, 2019
PCBs are synthetic organic chemical compounds of chlorine and biphenyl. Biphenyl is an aromatic hydrocarbon with molecular formula (C6H5)2. It is used as the starting material for the production of polychlorinated biphenyls (PCBs). They have been widely used as dielectric and coolant fluids in many electrical products. Unfortunately, they are toxic. Although no longer in use—they were banned in the 1970s—they are still contaminating rivers, lakes, and harbors and keep posing a threat to human health and to the environment. Previously, dredging and landfilling the PCBs has been the only effective remedy. An example is the ongoing project to dredge the upper Hudson River in New York State. Use of genetic engineering to culture PCB dechlorinators could pave the way for alternative, and possibly more effective, methods of degrading PCBs on-site: Dehalococcoides mccartyi is a tiny, strictly anaerobic bacterium that must derive its energy for growth by removing chlorines from chlorinated organic molecules and using them as electron acceptors for respiration, a process known as organohalide respiration.324 Along with two other bacteria of the Dehaloccoides family and seven known enzymes that act on chlorinated compounds, D. mccartyi could be used for bioremediation. Several research teams325 are working on new and effective ways to culture those microbes.
Effect of Biphenyl, Acetylene and Carbon Dioxide on Benzene Pyrolysis at Intermediate Temperatures
Published in Combustion Science and Technology, 2023
Mohammed Alabbad, Ribhu Gautam, Baqer Aljaman, Palani Arudra, Ahmad AlAhmadi
Biphenyl is a critical intermediate/product from benzene pyrolysis at intermediate temperatures. Three main pathways, namely radical π-bond addition, bi-radical combination and abstraction, lead to biphenyl formation, and each pathway forms several possible products. Tranter et al. (Tranter et al. 2010) have studied phenyl iodide pyrolysis in a shock tube coupled to time-of-flight mass spectroscopy (TOF-MS) and laser schlieren (LS) at a temperature range of 1276–1853 K. They studied phenyl radicals reactions and compared their results with previous studies (Comandini, Malewicki, and Brezinsky 2012; Hamadi et al. 2022; Laskin and Lifshit 1996; Saggese et al. 2013; Sun et al. 2021b). Recently, Jin et al. measured the rate constant for phenyl radical recombination reaction using laser absorption spectroscopy in a shock tube at a temperature range of 950–1300 K (Jin et al. 2021). Ring-opening route of phenyl radical requires high energy. Therefore, for benzene pyrolysis at low to intermediate temperatures, biphenyl is the major product (Saggese et al. 2013), while at high temperatures, small hydrocarbons, C2H2 and C4H2, are dominant (Laskin and Lifshit 1996).
Thermal conductivity of biphenyl with ethylene glycol liquid mixtures at T = 293.15–353.15 K
Published in International Journal of Ambient Energy, 2021
D. Venkatesan, D. Joshua Amarnath, J. Aravind Kumar, Baru Chandra Kiran, S. Balasubramanian
Some of the essential features of the heat transfer fluid and a chemical substance in process industries are: (a) excellent oxidation and chemical stability, (b) low volatility and (c) non-corrosiveness. Biphenyl also known as diphenyl is an aromatic hydrocarbon, with the molecular formula (C6H5)2, which is widely used as a dielectric and heat transfer agent, a crystalline biphenyl has been subjected to spectroscopic, calorimetric and crystallographic studies (Kennth Bates and Hazzard 1945). Ethylene glycol is one of the important chemicals in the process industries and is also well known as 1,2-ethanediol, which is mainly used commercially in the production of polyester fibres, chiefly polyethylene terephthalate, and also used as humectants, plasticiser, softener, etc. Ethylene glycol is also used as anti-freezing agent in aqueous form (Deng et al. ). It finds applications in many industries, for example, in motor vehicles, heat pumps, water heating systems and industrial cooling systems.