China
Africa
Explore chapters and articles related to this topic
Toxicological Chemistry of Chemical Substances
Published in Stanley E. Manahan, Environmental Chemistry, 2022
Ethylene oxide, a gaseous, colorless, sweet-smelling, flammable, explosive gas used as a chemical intermediate, sterilant, and fumigant, is moderately to highly toxic, a mutagen, and carcinogenic to experimental animals. Inhalation of relatively low levels of this gas results in respiratory tract irritation, headache, drowsiness, and dyspnea, whereas exposure to higher levels causes cyanosis, pulmonary edema, kidney damage, peripheral nerve damage, and even death. Propylene oxide is a colorless, reactive, volatile liquid (bp 34°C) with uses similar to those of ethylene oxide and similar, though less severe, toxic effects. The toxicity of 1,2,3,4-butadiene epoxide, the oxidation product of 1,3-butadiene, is notable in that it is a direct-acting (primary) carcinogen capable of forming DNA–DNA and DNA–protein cross-links.3
Polyols for Polyurethane Production
Published in Eric J. Goethals, Telechelic Polymers: Synthesis and Applications, 2018
David J. Sparrow, David Thorpe
Propylene oxide is produced from propylene by two routes: Chlorohydrin process: in which propylene is reacted with chlorine in water to give a chlorohydrin, which is then dehydrochlorinated with ring closure to give propylene oxide (Equation 2): ()Direct-oxidation process: in which propylene is reacted with an organic hydroperoxide in a molybdenum-catalyzed, liquid phase, radical reaction to yield propylene oxide. Two hydroperoxides are important industrially — t-butyl hydroperoxide and ethyl benzene hydroperoxide. T-butyl peroxide is produced from isobutane, and during the manufacture of propylene oxide is converted to t-butanol (Equation 3), which is then used as a fuel additive to enhance octane rating. Ethyl benzene hydroperoxide is prepared from ethyl benzene and subsequently converted to α-phenylethanol (Equation 4), which is then dehydrated to produce styrene. () ()
*
Published in Maurizio Cumo, Antonio Naviglio, Safety Design Criteria for Industrial Plants, 2019
Claudia Bartolomei, Sergio Paribelli
Toxicity — Propylene oxide is classified toxicologically as a primary irritant, a mild protoplasmic protein, and a mild depressant of central nervous system activity. Contact with the skin, even with diluted propylene oxide may result in irritation and necrosis of the skin. Excessive exposure to the vapor irritates the eyes, upper respiratory tract, and lungs. It is used as an insecticidal fumigant agent and as a food additive permitted in food for human consumption. TLV-TWA: 20 ppm; OSHA standard: TWA 100 ppm; TLm96: over 1000 ppm; and animal suspected carcinogen (IARC).
Energy and exergy assessments of dehydrogenation of propane for propene production
Published in Petroleum Science and Technology, 2018
Tianwei Wu, Qingbo Yu, Kun Wang, Wenjun Duan, Qin Qin
Propene is a significant building block in the petrochemical industry. Many chemicals can be manufactured by propene like polypropylene, propylene oxide and acrylonitrile (Corma et al. 2005; Zhang et al. 2013). For now, the propene is mainly manufactured by steam and fluid catalytic cracking of light oil fractions (SC and FCC) (Corma, Mengual, and Miguel 2013; Gao et al. 2010). Propene production by SC and FCC process needs high temperature, however, the high temperature could lead to the undesired decomposition of propene, which reduces the propene yield. Meanwhile, with the decreasing of oil resources, propene production by SC and FCC process has become more and more uneconomic. Recently, with the rapid development of shale gas industry, dehydrogenation of propane has been drawn more and more attention as an effective and economic propene production technology (Kang et al. 2015).
Development of a modular microreactor for the partial hydrocarbon oxidation
Published in Chemical Engineering Communications, 2018
Thomas Willms, Holger Kryk, Michael Wiezorek, Uwe Hampel
The production of TBHP by oxidation of liquid isobutane is an example for the partial oxidation of hydrocarbons. TBHP is used for numerous applications as for industrial polymerizations and oxidations as well as in organic synthesis. It becomes more and more important since the hydroperoxide is used to oxidize propylene to propylene oxide in the frame of the oxirane process. Propylene oxide is an important product for the manufacturing of polymers, antifreezing products etc. However, the production process of TBHP by the noncatalyzed oxidation of isobutane has still a big potential of improvement. The reaction is currently conducted in bubble-cap tray reactors and bubble columns at 120–140°C and 25–35 bar with a selectivity of about 60 mol% at a conversion of 45 mol% (Arpe, 2007). It is quite exothermic with a reaction enthalpy of −100 to −250 kJ/mol. An extremely simplified reaction scheme of this reaction is given by Equation (1).