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Halogen-Based FRs
Published in Asim Kumar Roy Choudhury, Flame Retardants for Textile Materials, 2020
There are four main groups of commercially produced brominated FRs (BFRs): Hexabromocyclododecane (HBCD) (Structure 5.1(a));Tetrabromobisphenol A (TBBPA) (Structure 5.1(b));Polybrominated biphenyl (PBB) (Structure 5.1(c)); andThree commercial mixtures of polybrominated diphenyl ethers (PBDEs) (Structure 5.1(d)): decabromo-diphenyl ether (deca-BDE), octabromodipheylether (octa-BDE), and pentabromo-diphenyl ether (Penta- BDEs) (Shaw et al., 2010).
Hybrid Plants for Thermal Energy Production
Published in Dimitris Al. Katsaprakakis, Power Plant Synthesis, 2020
The heat transfer fluid (HTF) in the receiver, usually a synthetic oil with high thermal conductivity, through its circulation in a closed loop, gathers the absorbed thermal energy from the solar collectors and transfers it to a series of heat exchangers (steam generators), where the transferred heat is utilized for the production of superheated steam, normally at temperatures of 370°C–400°C and pressures of 90–100 bars. The HTF inlet and outlet temperatures in and from the solar collectors field is at the range of 290°C and 390°C respectively. The produced steam is then led to the steam turbines for the production of mechanical power. The synthetic oil usually used is a eutectic mixture of 73.5% diphenyl ether oxide and 26.5% diphenyl ether. The main operational problem with this material is its high solidification temperature, around 12°C, due to which an auxiliary heat source is required during periods of low ambient temperature and solar radiation availability. Additionally, the boiling point of this employed synthetic oil under pressure of 1.013 bars is 257°C; hence, the synthetic oil inside the receiver's loop should be under pressure higher than the atmospheric one, together with an inert gas, such as nitrogen, argon, etc., in order to avoid its evaporation when its temperature becomes higher than the above mentioned boiling point.
Full Alphabetical Listing
Published in Allan F. M. Barton, and Solubility Parameters, 2018
In the absence of polymer-liquid interaction parameter values, the information compiled by Fuchs and Suhr370 may be noted. Solvents at elevated temperature were reported to be benzyl alcohol, phenol, chlorophenols, bromobenzene, aniline, formamide, N,N-dimethyl- formamide, malodinitrile,γ-butyrolactone, ethylene carbonate, diphenyl ether, benzyl benzoate. Nonsolvents included aliphatic hydrocarbons, lower alcohols, diethyl ether, and lower esters.
Levoglucosenone-derived synthesis of bio-based solvents and polyesters
Published in Green Chemistry Letters and Reviews, 2023
Cicely M. Warne, Sami Fadlallah, Adrian C. Whitwood, James Sherwood, Louis M. M. Mouterde, Florent Allais, Georg M. Guebitz, Con R. McElroy, Alessandro Pellis
Polyesters are usually synthesized in organic solvents such as diphenyl ether (DPE). This was found to be an excellent solvent for the synthesis of polyesters, achieving polymers of up to 10 kDa for polyesters containing diethyl succinate and 1,4-butanediol as the monomers (18). Furthermore, more complex polymers containing the diester derivatives of pyridine dicarboxylic acids have also been synthesized in DPE, and very successfully; 2,4-diethyl pyridine dicarboxylate and 1,8-octanediol produced a polymer with a number average molecular weight (Mn) of 14.3 kDa (19). Yet its use is problematic as it is extremely toxic to aquatic life and classed as highly hazardous due to its low flash point, auto-ignition temperature, and ability to form peroxides. Several alternative solvents have been investigated, such as short chain oxymethylene dimethyl ethers (OMEs). These gave a consistently higher yield when compared to DPE in the condensation of dimethyl adipate and various diols, but a lower Mn (20). Another previous work tested various alternative solvents in several polycondensation reactions of which pinacolone was the best performing, although only produced polymers with Mn of up to 2.5 kDa (21), which still falls short of DPE.
Kinetics study and reactor simulation of full-range low-temperature coal tar during hydrodeoxygenation process
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2019
Xu Liu, Dong Li, Xian Feng, Huaan Zheng, Limin Lu, Xiaoyong Fan, Wenhong Li
Recently, the research of mechanism and kinetics of hydrodeoxygenation (HDO) reaction has become a hotspot, which almost aim at model compounds or petroleum fraction. However, there are few studies on hydrofining kinetics of coal tar, especially full-range coal tar. Zhu et al. obtained the kinetic parameters and investigated the influence of reaction conditions on HDO reaction by response surface methodology (Zhu et al. 2015). Girgis and Gates reviewed the HDO network and kinetics of naphthol, phenol, benzofuran, and diphenyl ether (Girgis and Gates 1991). Novaes et al. established a phenomenological model to estimate the dynamic parameters of diesel HDT process (Novaes, Resende, and Salim et al. 2017). Toosi et al. established a steady-state three-phase model to simulate the hydrofining process of vacuum gas oil (Toosi et al. 2014).
New advance in the application of compound-specific isotope analysis (CSIA) in identifying sources, transformation mechanisms and metabolism of brominated organic compounds
Published in Critical Reviews in Environmental Science and Technology, 2022
Jukun Xiong, Guiying Li, Taicheng An
CSIA can provide vital information that clarifies the sources of BOCs in environment. Vetter et al. used a GC interfaced with a IRMS to analyze individual PBDE congeners in two technical PBDE products: DE-71 (pentabromo diphenyl ether mixture) and DE-79 (octabromo diphenyl ether mixture) (Vetter et al., 2008). In both products, a higher degree of bromination in products was associated with more negative δ13C values. The δ13C values of the three hexa-BDEs were more depleted in δ13C in more highly brominated technical octabromo diphenyl ether DE-79. This demonstrated that a carbon stable isotope analysis may support research about source and synthesis process associated with PBDE.