Control of ratio of rate of heat flow to rate of feed in distillation responsive to bottoms analysis

Claim 1

A METHOD FOR CONTROLLING THE OPERATION OF A FRACTIONAL DISTILLATION COLUMN, COMPRISING THE STEPS OF: PASSING A FEED INTO SAID COLUMN; CONTROLLING THE TEMPERATURE OF SAID FEED; PASSING A HEATING FLUID IN HEAT EXCHANGE RELATION WITH SAID COLUMN; MEASURING THE FLOW OF SAID FEED AND PRODUCING A FIRST SIGNAL PROPORTIONAL THERETO; MEASURING THE FLOW OF SAID HEATING FLUID AND PRODUCING A SECOND SIGNAL PROPORTIONAL THERETO; CONTROLLING THE FLOW OF SAID HEATING FLUID IN RESPONSE TO SAID FIRST AND SECOND SIGNALS TO MAINTAIN A PREDETERMINED RATIO OF THE FLOW OF SAID HEATING FLUID TO THE FLOW OF SAID FEED; ANALYZING KETTLE PRODUCT OF SAID COLUMN AND PRODUCING A THIRD SIGNAL PROPORTIONAL TO THE CONCENTRATION OF A SELECTED COMPONENT THERIN; AND ADJUSTING SAID RATIO IN RESPONSE TO SAID THIRD SIGNAL.