The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 12, 1993
Filed:
Mar. 02, 1992
James L Champion, Waterloo, IL (US);
Chung Y Shen, St. Louis, MO (US);
Chen-Hsyong Yang, Chesterfield, MO (US);
Monsanto Company, St. Louis, MO (US);
Abstract
There is disclosed an improved process for the semi-continuous production of phosphorus trichloride by the reaction of elemental phosphorus and chlorine in a liquid phosphorus trichloride layer. In accordance with the present invention periodic termination of the process by discontinuing phosphorus feed thereby creating a heel containing residual phosphorus is rendered more safe and less waste is produced by the improvement which comprises chlorinating the residual phosphorus at a substantially constant flow rate and continuing the chlorine feed rate until after observing at least one of either a step-wise decrease in the pressure within the reactor or a step-wise decrease in the flow rate of phosphorus trichloride removed from the reactor and then terminating the chlorine feed when said pressure and flow rate achieve a substantially steady state at a lower value.