Amoco Corporation

Harold A Lindahl

George A Huff

Kenneth J Abrams

Martin A Zeitlin

Leonard E Stark

Narasimhan Calamur

Norman F Brockmeier

Robert J Topliss

An olefins process is described which combines cracking of a hydrocarbon feedstock with the coupling of methane using an oxygen-affording gas such that the heat evolved in the exothermic methane coupling reaction is effectively transferred to the endothermic cracking process in a manner which does not allow the non-hydrocarbon products in the effluent of the methane coupling reaction to mix with the effluent of the cracking process. By combining the cryogenic requirements of the two processes, the refrigeration used in air liquifaction to separate oxygen for the methane coupling process can provide refrigerant nitrogen to liquify one or more of methane, ethylene and propylene which can be used in the cryogenic separation of the C.sub.2 + hydrocarbon products in the cracking process effluent.

Olefins process which combines hydrocarbon cracking with coupling methane

The control strategies include controlling the slurry concentration (SCON) by making an energy balance calculation around a slurry reactor and a material balance of liquid in, and liquid and solids out, of the reactor to determine the SCON. The feed rate of a diluent (hexane) stream into the reactor is adjusted to cause the SCON to approach or be at a target SCON. Further the control strategies include controlling the melt flow rate (MFR) by measuring the temperature and pressure in the slurry reactor and by gas chromatography, determining the ratio of hydrogen to propylene, calculating the MFR from a correlation developed from polypropylene process results from these parameters and then adjusting the feed rate of a hydrogen stream into the reactor to cause the MFR to approach or be at a target MFR which will yield a desired product of polypropylene.

Advanced control strategies for melt flow rate and reactor concentration

The method and apparatus for manufacturing terephthalic acid (TA) are capable of producing TA having a closely controlled, desired amount of contaminant, 4-carboxy-benazldehyde (4-CBA), therein and/or a closely controlled optical density. In the method, a feed of para-xylene or similar feedstock mixed with catalyst components and solvent system is fed to a reactor stage comprising one or more reactors with oxygen for carrying out an exothermic oxidation reaction in the reactor stage, and an output slurry from the reactor stage is fed with oxygen to a first crystallizer of a crystallizing stage. The method comprises the steps of: determining empirical relationships between (1) the desired level of contaminant in the TA output product from the crystallizing stage and the oxygen uptake in the first crystallizer and (2) the oxygen uptake in the first crystallizer and the CO.sub.2 in the vent gas from the reactor stage; monitoring the CO.sub.2 in the vent gas from the reactor stage; and, adjusting operating variables of the reactor stage within minimum and maximum constraints thereof to adjust the reactor vent CO.sub.2 to a desired level. Also, the method includes the steps of: determining empirically a mathematical relationship between the oxygen in the vent gas from the reactor stage and the opticals or optical density of the TA output product; monitoring the oxygen in the vent gases; and, adjusting the air intake to the reactor stage until the oxygen in the reactor vent gas is at a desired level to provide TA output product with a desired optical density. The apparatus includes one or more reactors, one or more crystallizers, and control devices for carrying out the various steps of the method.

Method and apparatus for controlling the manufacture of terephthalic

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Riverside, IL, United States of America

Harold A Lindahl