PRODUCTION OF DICHLOROBENZENE WITH HIGH PARA TO ORTHO RATIOS

摘要

A method for producing p-dichlorobenzene using a reactor containing a catalyst/reagent to convert chlorobenzene (or benzene) to p-dichlorobenzene, in a reactor has an inlet and an outlet for introducing reactants and removing product; introducing a pulse of gaseous chlorobenzene (or benzene) into the reactor and reacting the chlorobenzene with the catalyst/reagent whereby p-dichlorobenzene is formed; introducing a pulse ot inert gas into the reactor; introducing a pulse of gaseous chlorine into the reactor and reacting the chlorine with the catalyst/reagent; introducing a pulse of inert gas into the reactor; repeating the pulsing steps in a sequential manner; and continuously removing product containing p-dichlorobenzene from the outlet of the reactor. A further embodiment of the invention includes a method for producing a composition useful for producing p-dichlorobenzene having the steps of: Dissolving a catalyst/reagent adapted to produce pdichlorobenzene from chlorobenzene (or benzene) in a solvent to form a solution; contacting the solution with a porous inert substrate; and depositing the catalyst/reagent on the substrate. The porous inert substrate is preferably a resilient material such as vermiculite. The catalyst/reagent is preferably a mixture of FeCl3 and AlCl3 although FeCl3 alone may be used. Another embodiment encompasses apparatus for producing pdichlorobenzene from chlorobenzene (or benzene) that includes a gas supply that provides a source of gaseous chlorine, inert gas, and chlorobenzene (or benzene); a control and pulse-meter for receiving and controlling gases from the gas supply that switches between the sources of gaseous chlorine, inert gas, and chlorobenzene (or benzene) so as to provide pulses of each gas to the input of a reactor column; one or more reactor columns each having an input and an output and a catalyst/reagent composition disposed therein adapted to convert chlorobenzene (or benzene) to p-dichlorobenzene that accepts pulses of gases introduced from the pulse-meter at the input; and a separator for separating product gases from the output of the reactor.