Abstract:
A process for directly liquefying coal in a reactor including a preheating section and a reaction section, each having a plurality of pressure-resistant vertical pipes, comprises introducing into the preheating section a paste consisting of finely divided coal, catalyst and heavy oil. In the preheating section the paste is heated to a temperature of 380.degree. to 410.degree. C. and preheated hydrogen is blown into each pipe to create a velocity of Reynolds number equal to at least 3.times.10.sup.3 and an axial dispersion coefficient of not more than 0.05. The preheated paste and hydrogen are forwarded to the reaction section where they are heated to a temperature of 400.degree. to 500.degree. C. and further hydrogen is introduced into each pipe of the reaction section to maintain the velocity and axial dispersion values and a high partial pressure of hydrogen. The total quantity of hydrogen introduced is 1 to 3 times the stoichiometric value.
Abstract:
The gas to be polymerized is introduced into the working zone of a high pressure piston compressor and is compressed in timed relation to a pressure suitable for the polymerization. The gas temperature suitable for the polymerization process at the end of the compression stroke is set by cooling or heating the gas before the gas enters the compressor. The catalyst or initiator activating the polymerization is introduced into the working zone of the compressor during the compression stroke or after completion thereof, e.g. with the aid of a controlled injection valve. The gas containing the polymer and expanded approximately to the initial pressure is passed out of the compressor into a separator and is here freed from the polymer, while the residual gas is re-cycled to the compressor by means of a blower. For the polymerization of high-pressure polyethylene, the gas is compressed to a final pressure of about 2500 kg/cm.sup.2 at a temperature of about 130.degree. C. in the working zone of the compressor before introduction of the catalyst. The compressor may operate in a two-stroke or four-stroke cycle.
Abstract:
In a process for directly liquefying coal, a paste consisting of finely divided coal, catalyst and heavy oil can be treated for thermal cracking and hydrocracking with a high liquid/space ratio and short residence time in a preheating section and a reaction section. An apparatus threfor comprises a plural number of pipe units having apertures for hydrogen injection and apertures for the paste of a low concentration or heavy oil injection and a gas-liquid separator for removing H.sub.2 O, methane, etc., the pipe units being formed in such a manner that a Reynolds number of 3.times.10.sup.3 or greater and an axial dispersion coefficient of 0.05 or smaller are achieved for the fluid flow therein.
Abstract:
Lignocellulose is pulped batchwise by introducing it and the white liquor in predetermined quantity, together with a variable quantity of black liquor, into a continuously steam pressurized digester. When the cooking cycle has been completed, the pulp product is withdrawn. The time intervals of feed material introduction and pulp product withdrawal are correlated to insure that all of the lignocellulose charged to the digester is cooked uniformly, as by withdrawing the pulp product over a time interval which is substantially equal to the feed time. For economy and efficiency of operation, the digester preferably is operated in conjunction with one or more companion digesters to which it is connected. The first digester then is blown while a second digester is charged, making possible transfer of hot pressurized black liquor from the former to the latter.
Abstract:
The high pressure furnace comprises a cylindrical pressure vessel with front and rear pressure closures. An electrical heating element is supported within the interior of the pressure furnace. The front closure supports a relatively thin-walled inner container opening only to an aperture in the front closure. A small closure plugs the aperture. A reaction frame secures the various closures. Blanket gases are introduced into the furnace chamber and process gases into the process chamber defined by the interior of the inner container. Means are provided for minimizing the pressure difference across the inner container to enable it to maintain its original shape.
Abstract:
An apparatus for treating a workpiece at elevated temperatures and pressures comprising an elongate cylindrical pressure vessel. Within the pressure vessel a hearth sits upon a pedestal. Surrounding the pedestal and the workspace immediately thereabove is an insulated furnace enclosure. A cavity near the base of the pedestal defines an impeller chamber. An impeller is positioned in the chamber and has a downwardly extending drive shaft. The impeller circulates the pressurized atmosphere. A remotely actuated gate directs the circulating atmosphere to either circulate totally within the furnace enclosure or partially within the furnace enclosure and partially along the interior wall of the pressure vessel.
Abstract:
A high-temperature, fluid-wall chemical reactor can be equipped with a variable profile, counterflow heat exchanger and a reaction product control system. The heat exchanger includes two tubular walls, positioned concentric of one another, and a spiral baffle disposed between the two walls to define a spiral, annular coolant channel. The walls and baffle are made of a refractory material. The heat exchanger has an inlet and an outlet to permit a coolant to be circulated through the coolant channel. The reaction product control system includes a reaction product analyzer and means for withdrawing and transferring samples of reaction product exiting the reactor. The reaction product analyzer can receive samples of reaction product and generate a signal corresponding to deviations between the chemical composition of the product and a preselected composition. The control system also includes a reactor temperature controller to vary a temperature of the reactor in response to the signal from the reaction product analyzer to reduce the deviations.
Abstract:
A high pressure, high temperature reactor device having a pair of spaced tube sheets for supporting a tube nest, one tube sheet being formed with a bellows to compensate for expansion and contraction of the tube nest longitudinally during temperature changes and the second tube sheet supporting the opposite end tubes of the tube nest, with injector tubes mating with each reactor tube and projecting through the reactor shell.
Abstract:
Continuous production of iso- or terephthalic acid in a stirred reaction zone by catalytic air oxidation of m- or p-xylene in the presence of a benzoic acid-water liquid solvent system at constant gauge pressure within the range of 7 to 21 kg/cm.sup.2 wherein oxidation temperature within the range of 175.degree. to 235.degree. C. is maintained substantially constant by the novel control thereof by only varying the flow rate of water condensate reflux to the oxidation zone. The invention further pertains to novel means for achieving such temperature control.Also, the present invention relates to a novel continuous recovery of the phthalic acid product from the fluid effluent of said continuous process by a process wherein crystalline phthalic acid product is separated from essentially water-free benzoic acid mother liquor; the crystalline product is successively washed with liquid benzoic acid and the corresponding xylene; the washed product is dried; and the water removed from said fluid effluent, the benzoic acid and xylene wash liquors, xylene recovered from product drying, and a major proportion of the benzoic acid mother liquor are charged to the oxidation process.The invention further relates to a novel combination of apparatus for the continuous conduct of said oxidation and recovery processes.
Abstract:
The present invention concerns a reactor of the tubular type, with a high heat exchange, for the catalytic production under high pressure of alpha-olefine polymers and copolymers, in particular polymers and copolymers of ethylene.More particularly, the tubular reactor of this invention consists of three coaxially arranged tubes, distanced from each other in such a way as to create between the outer tube and the intermediate an annular interspace suited for the circulation of the refrigerating fluid and between the intermediate tube, sized for very high pressures, and the innermost tube an interspace that will form the exothermic reaction zone proper, said innermost tube being of the low-pressure type and forming the preheating zone of the process fluid, fed in under pressure from the outside by the action of the reaction heat that develops inside said intermediate tube, said preheating zone extending up to over half the length of the reactor and, at the end of it, defining the reaction starting zone that is the feeding zone of the catalyst or the like, means for the control of the temperature in said reaction starting zone through the immission of fresh process fluid into the reaction starting zone itself, said process fluid having been drawn from the inlet of the reactor or, by the recycling, into the inlet of the reactor, of process fluid drawn from the end of the preheating zone and refrigerated, as well as means for balancing the pressures between said reaction zone and said preheating zone.