Plant for the synthesis of urea, comprising: a synthesis section comprising at least one reactor, a compressor for supplying CO.sub.2 to said synthesis section, a gas turbine for the operation of said CO.sub.2 compressor and a heat recovery steam generator; the heat source of said heat recovery steam generator consists of the exhaust gases of said gas turbine, and at least one steam flow produced by said heat recovery steam generator is used as heat source for at least one component of said urea plant.

A system and method for preparing a vanadium battery high-purity electrolyte, comprising preparing a low-valence vanadium oxide with a valence of 3.5 with liquid phase hydrolysis and fluidization reduction with vanadium oxytrichioride, adding clean water and sulfuric acid for dissolution, and further performing ultraviolet activation to obtain the vanadium electrolyte, for use in an all-vanadium redox flow battery stack. The high-temperature tail gas in the reduction fluidized bed is combusted for preheating the vanadium powder material, to recover the sensible heat and latent heat of the high-temperature tail gas, and the sensible heat of the reduction product is recovered through heat transfer between the reduction product and the fluidized nitrogen gas. An internal member is arranged in the reduction fluidized bed to realize the precise regulation of the valence state of the reduction product, and ultraviolet is used to activate the vanadium ions, improving the activity of the electrolyte.

A system and method for producing a high-purity and high-activity vanadium electrolyte, comprising converting high-purity vanadium oxytrichloride into an ammonium salt in a fluidized bed by gas phase ammoniation, then in another fluidized bed, reducing the ammonium salt into a low-valence vanadium oxide having an average vanadium valence of 3.5, adding clean water and sulfuric acid for dissolution, and further performing activation by ultrasound to obtain a 3.5-valence vanadium electrolyte which can be directly used in a new all-vanadium redox flow battery stack. The method of producing an ammonium salt containing vanadium in the fluidized bed by gas phase ammoniation is of short process and high efficiency. Precise regulation of the valence state of the reduction product is implemented by arranging an internal member in the reduction fluidized bed, and ultrasonication is used to activate the vanadium ion, thereby greatly improving the activity of the electrolyte.

The present invention provides an improved process for removing heat from an exothermic reaction. In particular, the present invention provides a process wherein heat can be removed from multiple reaction trains using a common coolant system.

Method of producing hydrogen sulfide in an alkaline environment. A mixture having a sodium salt, elemental sulfur (S) and water is added to a reactor for the purpose of generating hydrogen sulfide (H.sub.2S) gas as the main product and sodium sulfate (Na.sub.2SO.sub.4) as a byproduct.

Related to is a system for preparing xylose liquid by continuously hydrolyzing hemicellulose, including a neutralizing unit, an acid-adjusting unit, a feeding unit, a liquefaction ejecting unit, a feed and discharge heat-exchanging unit and a discharge controlling unit. The neutralizing unit includes a raw material tank, a neutralizing concentrated sulfuric acid pump and a neutralizing pipeline mixer, the acid-adjusting unit includes an acid-adjusting concentrated sulfuric acid pump, an acid-adjusting pipeline mixer and an acid-adjusting tank, the feeding unit includes a feed tank, the liquefaction ejecting unit includes a liquefaction ejector and a liquefaction maintainer, the feed and discharge heat-exchanging unit includes a plate-type teed and discharge heat exchanger and a first discharge temperature sensor, and the discharge controlling unit includes a discharge valve and a reflux valve. The obtained xylose liquid exchanges heat with the hemicellulose liquid in the plate-type feed and discharge heat exchanger to decrease a temperature of the xylose liquid, whereas a temperature of the hemicellulose liquid is increased. Further disclosed is a method using the system. The simultaneous feed and discharge heat exchanges greatly reduce energy consumption, and feed and exchange are continuously run, thereby improving the production efficiency and simplifying manual operations.

A device for carrying out a chemical reaction by a continuous method has a reactor with at least two reactor sections which define a direction of flow. The reactor has plug flow properties along the direction of flow. A recirculation line is present to withdraw a partial flow from the reactor at a first point and return it to the reactor at a second point located above the first point in the direction of flow. Means are provided which prevent a temperature increase in the reactor over a predetermined temperature range, for example change of more than approximately 50 K.

A device includes an insulated reaction chamber, light sources above a stirring module, the light sources surrounding the reaction chamber, and holders containing reaction vessels, the holders configured to fit within the insulated reaction chamber in a manner that enables an even distribution of light between the reaction vessels.

A heating system for a vehicle includes a reaction space (16) containing a first reactant (22) and a reactant storage space (20) containing or/and receiving a second reactant (24), wherein the first reactant and the second reactant form such a reaction system. A reaction of the first reactant with the second reactant produces a reaction product that releases heat. The second reactant can be separated from the first reactant by introducing heat into the reaction product. A reactant-releasing device (26) releases second reactant from the reactant storage space into the reaction space (16). A first heat removal device (58) removes heat from the first reactant or/and reaction product contained in the reaction space (16). A heating unit (52) heats the first reactant or/and heats the reaction product contained in the reaction space. A reactant-recirculating device (36) recirculates second reactant from the reaction space into the reactant storage space.

The present invention provides an improved process for removing heat from an exothermic reaction. In particular, the present invention provides a process wherein heat can be removed from multiple reaction trains using a common coolant system.