Caltech Library System

About | Browse | Search | Caltech Student Instructions

Type of Document	Dissertation
Author	Rinker, Robert Gene
URN	etd-02172006-104009
Persistent URL	http://resolver.caltech.edu/CaltechETD:etd-02172006-104009
Title	I. Studies in the chemistry of sodium dithionite. II. A preliminary study of the catalyzed addition of hydrogen chloride to vinyl chloride in a stirred reactor
Degree	PhD
Option	Chemical Engineering
Advisory Committee	Advisor Name Title William Harrison Corcoran Committee Chair
Keywords	none
Date of Defense	1959-01-01
Availability	unrestricted
Abstract NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. Part I: Rate studies of the air oxidation and thermal decomposition of aqueous sodium dithionite, Na2S2O4, were conducted. These experiments were supplemented by studies of the electron-paramagnetic-resonance properties and the electrolytic formation of dithionite. In the air-oxidation experiments, the overall rate was observed to have half-order dependence on the dithionite concentration and a first-order dependence on molecular oxygen concentration. This could be explained mechanistically on the basis of an instantaneous equilibrium reaction between dithionite and the [...] radical ion. The results of the EPR studies confirmed the presence of [...] and established the existence of equilibrium between the free radical and dithionite. The electrolytic production of dithionite from a bisulfite solution gave current efficiencies of 75% but did not show conclusively that the reduction was either a one- or two-electron transfer process. In the thermal decomposition studies, the overall rate showed a 3/2-order dependence on dithionite concentration and a half-order dependence on hydrogen ion concentration. A mechanism involving [...] or a protonated form of the radical in a reaction with the dimer appeared to fit the observed facts. Part II: A preliminary rate study of the catalyzed addition-reaction between HCl and vinyl chloride was conducted in a continuous-flow stirred reactor. Gas-phase chromatography was used in the analysis of the chemical constituents. The rate data for the primary reaction appeared to fit, at least empirically, a second-order rate law with respect to the forward reaction. In addition to the primary reaction, fouling of the catalyst, ZnCl2, was also observed, but the decreasing conversion as a function of catalyst-exposure time reached an asymptotic value greater than zero. This indicated that the catalyst fouling was an irreversible dual-site mechanism. The fact that 1,1 dichloroethane was formed exclusively in the primary reaction eliminated the possibility of a free-radical reaction. Because of the relatively low rate of reaction, even in the presence of a catalyst, the addition probably occurred by a four-center-type mechanism.
Files	Filename       Size       Approximate Download Time (Hours:Minutes:Seconds)     28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access    Rinker_rg_1959.pdf 22.62 Mb 01:44:42 00:53:50 00:47:07 00:23:33 00:02:00