In a general aspect, a system can include a reactor for combusting fuel and producing high-temperature, high-pressure liquid as a byproduct, and at least one vessel defining a cavity to be partially filled with water, with an air pocket within the cavity above the water. The system can further include respective valves to control admission of liquid from the reactor into the air pocket when the air pocket has a pressure lower than an operating pressure of the reactor, and to control emission of the water from the at least one vessel through of the vessel after the water in the at least one vessel has been pressurized by the liquid from the reactor. The system can also include a hydroelectric drive system for receiving water emitted from the cavity, and for converting energy in the received water into electrical energy.

An exhaust gas after-treatment system includes a first reactor installed in an exhaust flow path, a second reactor disposed at a downstream side from the first reactor, a first reducing agent injection unit and a second reducing agent injection unit configured to respectively inject a reducing agent toward the exhaust gas to be introduced into the first reactor and the second reactor, a first temperature sensor and a second temperature sensor configured to respectively measure a temperature of the exhaust gas to be introduced into the first reactor and the second reactor, and a control device configured to control whether to inject the reducing agent from the first and second reducing agent injection units and the amount of reducing agent to be injected on the basis of temperature information provided by the first and second temperature sensors.

A monitoring system for monitoring a process includes a housing with a viewing panel. The viewing panel includes a view port. An emitter generates light and illuminates an observation zone of the process. A detector is disposed within the housing and is configured to detect light entering the housing through the view port and create a plurality of images of the process in the observation zone. A thermal regulation system is configured to generate heat in the vicinity of the viewing panel of the housing so as to increase the temperature of at least the view port above ambient temperature.

A reactor system for producing modacrylic polymer having a main tank with at least one feed inlet, a mixing element inside the main tank, a secondary tank connected to the main tank with an overflow channel, a reaction terminator feed and a level meter for the secondary tank, an outlet at the bottom of the secondary tank, a level control valve that controls the outlet, a collection area connected to the outlet, and a control unit configured to control the level control valve to determine output amount to be transferred to the collection area from the secondary tank according to data received from the level meter in order to keep the level in the secondary tank constant. The temperature in the main tank and the secondary tank is continuously measured and the main tank and the secondary tank temperature difference is arranged such that it does not exceed +5° C.

A process for performing a continuous gas/liquid biphasic high-pressure reaction, wherein a gas and a liquid are introduced into a backmixed zone of a reactor and in the backmixed zone the gas is dispersed in the liquid by stirring, injection of gas and/or a liquid jet, a reaction mixture consecutively traverses the backmixed zone and a zone of limited backmixing, and a liquid reaction product is withdrawn at a reaction product outlet of the zone of limited backmixing, wherein the reactor comprises: an interior formed by a cylindrical vertically oriented elongate shell, a bottom and a cap, wherein the interior is divided by means of internals into the backmixed zone, the zone of limited backmixing and a cavity, a first cylindrical internal element which in the interior extends in the longitudinal direction of the reactor and which delimits the zone of limited backmixing from the backmixed zone, backmixing-preventing second internal elements in the form of random packings, structured packings or liquid-permeable trays arranged in the zone of limited backmixing and a third internal element which in the interior extends in the longitudinal direction of the reactor and is open at the bottom, wherein the third internal element forms the cavity in which gas bubbles collect and do not escape upwards, thus preventing the volume of the cavity from being occupied by liquid and reducing the reaction volume. The reaction volume of the reactor used in the process can be reversibly reduced in simple fashion. The invention further relates to a process for adapting the reaction volume of a reactor suitable for performing a gas/liquid biphasic high-pressure reaction having an outlet for a liquid reaction product in which an internal element is arranged so as to form a cavity open at the bottom in which gas bubbles collect and do not escape upwards, thus preventing the volume of the cavity from being occupied by liquid and reducing the reaction volume.

Provided is an apparatus for preparing oligomer including: a reactor for carrying out oligomerization reaction by supplying a monomer stream and a solvent stream; and line 1 and line 2 which are separately provided in a lower side of the reactor, wherein line 1 includes a first level control valve and line 2 includes a second level control valve, and the reactor is periodically alternately operated in first operation mode and second operation mode, thereby switching a pipe through which the product is discharged, so that a plugging phenomenon of the pipe through which the product is discharged and the valve can be prevented.

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 process for performing a continuous gas/liquid biphasic high-pressure reaction, wherein a gas and a liquid are introduced into a backmixed zone of a reactor and in the backmixed zone the gas is dispersed in the liquid by stirring, injection of gas and/or a liquid jet, a reaction mixture consecutively traverses the backmixed zone and a zone of limited backmixing, and a liquid reaction product is withdrawn at a reaction product outlet of the zone of limited backmixing, wherein the reactor comprises: an interior formed by a cylindrical vertically oriented elongate shell, a bottom and a cap, wherein the interior is divided by means of internals into the backmixed zone, the zone of limited backmixing and a cavity, a first cylindrical internal element which in the interior extends in the longitudinal direction of the reactor and which delimits the zone of limited backmixing from the backmixed zone, backmixing-preventing second internal elements in the form of random packings, structured packings or liquid-permeable trays arranged in the zone of limited backmixing and a third internal element which in the interior extends in the longitudinal direction of the reactor and is open at the bottom, wherein the third internal element forms the cavity in which gas bubbles collect and do not escape upwards, thus preventing the volume of the cavity from being occupied by liquid and reducing the reaction volume. The reaction volume of the reactor used in the process can be reversibly reduced in simple fashion. The invention further relates to a process for adapting the reaction volume of a reactor suitable for performing a gas/liquid biphasic high-pressure reaction having an outlet for a liquid reaction product in which an internal element is arranged so as to form a cavity open at the bottom in which gas bubbles collect and do not escape upwards, thus preventing the volume of the cavity from being occupied by liquid and reducing the reaction volume.

Provided are a method and an apparatus for producing 1,2,3,4-tetrachlorobutane that are unlikely to lose 3,4-dichloro-1-butene as the material or 1,2,3,4-tetrachlorobutane as the product and can be stably and economically produce 1,2,3,4-tetrachlorobutane. A reaction liquid (1) containing 3,4-dichloro-1-butene is placed in a reaction container (11), then chlorine gas is supplied to a gas phase (2) in the reaction container (11), and the 3,4-dichloro-1-butene is reacted with the chlorine gas to give 1,2,3,4-tetrachlorobutane.

The present invention is concerned with a process for providing a homogeneous particle-containing slurry comprising the steps of: (a) providing a vessel comprising at least one impeller rotating around a vertical axis of the vessel, wherein a rotational speed n.sub.1 of the at least one impeller is higher than n.sub.min according to equation (1), the vessel further comprising an inlet and an outlet; (b) introducing a particle-containing slurry into the vessel or introducing components forming the particle-containing slurry into the vessel; (c) rotating the at least one impeller at least around the vertical axis for homogenizing and/or maintaining a homogeneous particle distribution within the slurry; (d) withdrawing the homogeneous particle-containing slurry via the outlet; (e) reducing the rotational speed n.sub.1 of the at least one impeller to a reduced rotational speed n.sub.red, whereas n.sub.red is lower than n.sub.1 and higher or equal gas inlet than n.sub.min according to equation (1):

[00001]$\begin{array}{cc}{n}_{\min }=\frac{S{v}^{0.1}{D_p^{0.2}\left(g\frac{\Delta \rho }{{\rho }_f}\right)}^{0.45}{B}^{0.13}}{D_a^{0.85}}& \left(1\right)\end{array}$