Olefin oxidation reactor temperature control

Claim 1

An arrangement for controlling the temperature of a reactor for containing a reaction from at least one reactant to at least another product, the reactor having a feed line for the reactant and an effluent line for the product, comprising: a feed flow transmitter connected to the feed line for measuring the flow F 1 of reactant to the reactor; an effluent flow transmitter connected to the effluent line for measuring the flow F 2 of product from the reactor; a feed temperature transmitter connected to the feed line for sensing the reactant temperature T I ; an effluent temperature transmitter connected to the effluent line for measuring the product temperature T O ; at least one reactor temperature transmitter connected to the reactor for measuring a temperature of reactor T R ; a concentration transmitter connected to the effluent line for measuring the concentration of the at least one product in the effluent line; a coolant flow line to the reactor for supplying coolant to the reactor at a coolant flow rate; coolant flow control means in said coolant line; and circuit means connected to all of said transmitters and to said coolant flow control means for controlling the flow of coolant to the reactor according to a coolant flow signal, said circuit means receiving quantities proportional to the heat of reaction for at least one reaction in the reactor, specific heats of the reactant and product, and the heat of vaporization of the coolant, said circuit means operable to obtain values for changes per unit time in feed flow rate ΔF 1 , effluent flow rate ΔF 2 , feed temperature ΔT I , reactor temperature, ΔT R , effluent temperature ΔT O , and concentration of at least one product Δ y , said circuit means including circuit components for multiplying each change per unit time by a characteristic factor said circuit means including circuit elements for generating factors as follows: ##EQU9## said coolant flow signal being changed by a quantity ΔQ in said circuit means which is calculated as follows: ##EQU10## wherein: λ=coolant heat of vaporization y 1 =a first product condensation ΔH 1 =heat of reaction of reactant to first product y 2 =a second product concentration ΔH 2 =heat of reaction of reactant to second product C P .sbsb.1 =specific heat of effluent, and wherein ethylene plus oxygen is supplied to the reactor as reactant and ethylene oxide plus carbon dioxide and water are generated as products, y 1 being the concentration of ethylene oxide, y 2 being the concentration of carbon dioxide, ΔH 1 being the heat of reaction of ethylene plus oxygen to ethylene oxide, ΔH 2 being the heat of reaction of ethylene plus oxygen to carbon dioxide.