• Applied Chemistry for Engineering
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• v.21 no.3
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• pp.295-300
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• 2010

A binary system of 1-propanol and bromochloromethane which exhibits an azeotropic point and a considerable nonideal phase behavior probably due to the large boiling point difference is not amenable in the actual chemical processes such as the distillation tower and absorber. Therefore, experimental data of phase behavior data of this mixture are indispensable in understanding the inherent thermodynamic characteristics for an efficient application of the system in the industrial processes. In this work, the isobaric vapor-liquid equilibrium of a binary mixture consisting of 1-propanol and bromochloromethane was measured by using a recirculating equilibrium cell at various pressures ranging from 30 to 70 kPa. The measured VLE data were correlated in a satisfactory manner by using the UNIQUAC and NRTL models along with the thermodynamic consistency test based on Gibbs/Duhem equation. In addition, the excess molar volume of the mixture was also measured by using a vibrating densitometer and correlated with a Redlich-Kister polynomial.

• Journal of Life Science
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• v.22 no.9
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• pp.1187-1193
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• 2012

This study was conducted to evaluate effects of halogenated compounds on in vitro rumen fermentation characteristics and methane emissions. A fistulated Holstein cow of 650 kg body weight was used as a donor of rumen fluid. Five kinds of halogenated compounds (bromochloromethane (BCM), 2-bromoethane sulfonic acid (BES), 3-bromopropanesulfonic acid (BPS), chloroform (CLF), and pyromellitic diimide (PMDI) known to inhibit methyl-coenzyme M reductase activity were added to an in vitro fermentation incubated with rumen fluid. The microbial population including bacteria, protozoa, and fungi were enumerated, and gas production including methane and fermentation characteristics were observed in vitro. The pH values ranged from 6.25 to 6.72 in all the treatments, and these showed a similar level at 48 hr. The total gas production in the treatments showed a similar pattern with C at 48 hr, whereas methane production in the treatments was lower (p<0.05) than C. Concentrations of total volatile fatty acids (VFAs) and propionic acid were higher (p<0.05) in the treatments than in C at 12 hr. Therefore, halogenated compounds (BCM, BES, BPS, CLF, and PMDI) inhibited in vitro methane emissions by inhibiting methanogens in the rumen. Further studies on safety are needed.