A high-purity chlorine dioxide gas may use hydrogen peroxide as a reducing agent and may use horizontal generator, evaporation crystallizer, dryer and other devices to produce chlorine dioxide gas (product) and sodium sulfate (by-product). Compared to the conventional chlorine dioxide preparation system, the chlorine dioxide reaction and the sodium sulfate crystallization are performed in two processes. These processes are relatively separate and independent, and continuously produce chlorine dioxide gas with high purity and low moisture content while the by-product salt cake is evaporated, crystallized, filtered and dried, thereby producing sodium sulfate, without generating solid and liquid waste.

A method for preparing a purified styrene composition with a styrene yield of at least 80%. The method comprises providing a crude composition containing styrene, and subjecting the crude composition to at least one crystallization step. The at least one crystallization step comprises at least one static crystallization stage and at least one dynamic crystallization stage.

The present invention relates to the technical field of chemical industry, and in particular to a method for purifying ethylene carbonate through dynamic crystallization, which includes the following steps: adding an ethylene carbonate-containing raw material into a cavity of a crystallization device under a condition of stirring for dynamic crystallization, wherein the crystallization device further includes a jacket attached and circumferentially disposed along the outer wall of the cavity, the jacket is provided with cooling water therein, a temperature of the cooling water is 1-2.5? C. lower than the temperature in the cavity until a granular ethylene carbonate crystal is generated. The present invention using a rake dryer as the crystallization device to realize dynamic crystallization at a certain rotating speed. The technical solution is simple to operate and short in processing cycle, which facilitates improvement in production efficiency and product quality and is suitable for industrial application.

This disclosure provides systems and methods for direct production of lithium hydroxide by utilizing cation selective, monovalent selective, or preferably lithium selective membranes. Lithium selective membranes possess high lithium selectivity over multivalent and other monovalent ions and thus prevent magnesium precipitation during electrodialysis (ED) and also address the presence of sodium in most naturally occurring brine or mineral based lithium production processes.

Processes and systems for separating a mixture including at least one fluorocarboxylic acid and at least one carboxylic acid are provided herein. In some aspects, the present invention relates to processes and systems configured to provide a purified stream of fluorocarboxylic acid and a purified stream of carboxylic acid, even when the mixture includes an azeotrope, a pinch point, and/or a eutectic mixture of the fluorocarboxylic acid and carboxylic acid. Systems as described herein may include, for example, at least one distillation zone and at least one fractional crystallization zone arranged in series and configured to provide highly purified product streams having compositions heretofore unachievable by conventional means.

The present invention relates to a reactor, and according to one aspect of the present invention, there is provided a reactor comprising a housing provided with a reaction space, a tube disposed inside the housing, an impeller provided inside the housing to allow reactants in the reaction space to flow into and out of the tube and a nozzle provided to spray a liquid from the reaction space toward the housing wall surface side.

Embodiments relate to systems and methods directed towards arrangements of a preheater, a heat exchanger, a plasma recovery system, and at least one processing stage configured to use steam output of a calciner for heating incoming wastewater that is being processed.

The present application relates to a method for preparing L-methionine crystals with an improved bulk density. As the L-methionine crystals prepared according to the method for preparing L-methionine crystals of the present application may have a bulk density of up to 800 g/L, the L-methionine crystals are expected to reduce storage and transport costs of L-methionine powder and improve working conditions due to improved fluidity of the powder.

The present invention relates to an apparatus and a method for preparing bisphenol A, and provides an apparatus and a method for preparing bisphenol A that can increase the energy efficiency of the entire process by utilizing an internal heat source.

In a method and an apparatus for recovering chemicals from an alkaline lignin material, the alkaline lignin material (3) which comprises NaOH or KOH is precipitated in presence of an acid in a precipitation stage (6) for forming a precipitated lignin (7), the precipitated lignin (7) is supplied to a separation stage (8) in which a purified lignin (9) is recovered and from which at least one fraction (10) which comprises Na or K is supplied to a crystallization stage (11), and the fraction (10) which comprises Na or K is treated by crystallization in the crystallization stage (11) for forming a crystallized compound (12). Further, the invention relates to use of the purified lignin, and lignin and chemical products.