Described herein is a continuous process for producing polyurethane prepolymers in a residence time reactor with plug flow. Also described herein is a method of using these prepolymers for producing polyurethanes.

A chemical reaction apparatus includes a horizontal flow-type reactor in which a content horizontally flows with an unfilled space being provided thereabove, a microwave generator that generates microwaves, and at least one waveguide that transmits the microwaves generated by the microwave generator to the unfilled space in the reactor.

A method is described for shutting down a Fischer-Tropsch reactor fed with a reactant gas mixture comprising a synthesis gas and a recycle gas recovered from the Fischer-Tropsch reactor in a synthesis loop, said Fischer-Tropsch reactor containing a Fischer-Tropsch catalyst cooled indirectly by a coolant under pressure, comprising the steps of: (a) depressurising the coolant to cool the reactant gas mixture to quench Fischer-Tropsch reactions taking place in the Fischer-Tropsch reactor, (b) stopping the synthesis gas feed to the Fischer-Tropsch reactor, and (c) maintaining circulation of the recycle gas through the Fischer-Tropsch reactor during steps (a) and (b) to remove heat from the Fischer-Tropsch reactor. The method safely facilitates a more rapid return to operating conditions than a full shut-down.

A process and system for maintaining optimum polymerization production in a loop polymerization reactor by continuously and periodically obtaining polymerization results, such as melt index (MI), production rate and ash content of the polymer produced, determining whether each of the results is within desired ranges, storing and averaging recently obtained results in a database within a reaction rate controller program, and when one of the results is out of the desired range modifying at least one reaction parameter set-point such as monomer concentration, catalyst feed rate and reactor temperature to drive any out-of-range polymerization result(s) toward the desired range for that result.

A feed gas feeding system for a propylene ammoxidation reactor comprises a feed gas mixing system and a feed distributor, wherein a propylene and ammonia mixed gas is mixed by the feed gas mixing system and then uniformly distributed in the propylene ammoxidation reactor by the feed distributor. The initial temperature T.sub.0 when the propylene and ammonia mixed gas enters the feed distributor is 10-220° C. The feed gas feeding system can prevent the temperature of the gas mixture at any position in the feed distributor from reaching a temperature at which ammonia decomposes into active nitrogen atoms, thereby reducing a risk of brittle nitriding fractures of the feed distributor.

A process includes periodically or continuously introducing an olefin monomer and periodically or continuously introducing a catalyst system or catalyst system components into a reaction mixture within a reaction system, oligomerizing the olefin monomer within the reaction mixture to form an oligomer product, and periodically or continuously discharging a reaction system effluent comprising the oligomer product from the reaction system. The reaction system includes a total reaction mixture volume and a heat exchanged portion of the reaction system comprising a heat exchanged reaction mixture volume and a total heat exchanged surface area providing indirect contact between the reaction mixture and a heat exchange medium. A ratio of the total heat exchanged surface area to the total reaction mixture volume within the reaction system is in a range from 0.75 in.sup.−1 to 5 in.sup.−1, and an oligomer product discharge rate from the reaction system is between 1.0 (lb)(hr.sup.−1)(gal.sup.−1) to 6.0 (lb)(hr.sup.−1)(gal.sup.−1).

A process and system for maintaining optimum polymerization production in a loop polymerization reactor by continuously and periodically obtaining polymerization results, such as melt index (MI), production rate and ash content of the polymer produced, determining whether each of the results is within desired ranges, storing and averaging recently obtained results in a database within a reaction rate controller program, and when one of the results is out of the desired range modifying at least one reaction parameter set-point such as monomer concentration, catalyst feed rate and reactor temperature to drive any out-of-range polymerization result(s) toward the desired range for that result.

A biomass torrefaction system includes a reactor vessel for biomass particles, a burner for combusting one or more fuels to produce a heated gas, a fan for supplying a flow of the heated gas through the reactor vessel to heat the biomass particles, and a controller configured to calculate a torrefaction index according to one or more sensed parameters of the system. The sensed parameter(s) include at least one of a reactor vessel retention time, a reactor vessel temperature difference and a higher heating value (HHV) of a syngas output by the reactor vessel. The controller is also configured to automatically adjust one or more operation values of the system according to the calculated torrefaction index. The operation value(s) include at least one of the reactor vessel retention time, a heating rate of the system, and a mixture of the one or more fuels combusted by the burner.

Disclosed herein are various examples of systems, methods and devices for an oxygen reduction system with a universally compatible, adaptive front end that can be coupled with various different gas sources, wherein the oxygen reduction system determines its operations separate and independent from any signal lines from any upstream components or systems. In one example, the oxygen reduction system determines its functions, operations, and operational states from parameters that it measures from the input gas stream and other internal measurements. In this manner, installation of an oxygen reduction system is simplified, time-efficient and universal, and embodiments of the present disclosure provide for oxygen reduction systems that can be installed in a variety of different environments, applications, and with new or existing natural gas productions sites.

Processes for controlling the rate and temperature of cooling fluid through a heat exchange zone in, for example, an alkylation reactor using an ionic liquid catalyst. A cooling fluid system may be used to provide the cooling fluid which includes a chiller and a reservoir. The cooling fluid may pass from the reservoir through the heat exchange zone. A bypass line may be used to pass a portion of the cooling fluid around the heat exchange zone. The amount of cooling fluid may be adjusted, with a valve, based upon the temperature of the cooled process fluid flowing out of the heat exchange zone. Some of the cooling fluid from the chiller may be circulated back to the chiller in a chiller loop.