Sk Innovation Co., Ltd.

Sk Global Chemical Co., Ltd.

Sung Real Son

In Hyoup Song

Suk Joon Hong

Ji Min Kim

Yoon Jae Yim

Min Ji Sung

Young Bo Choi

Sang Il Lee

Tae Seung Kim

Hyeon Bae Ha

Jung Yul Son

Sang Uk Kim

Dae Hyun Choo

Sang Hyun Cho

Sang Hye Shin

Dong Wook Ha

Ji Yun Park

Choon Hwan Song

Hyeon Jung Kim

In a method of recovering an active metal of a lithium secondary battery, a cathode active material mixture is prepared from a waste cathode of a lithium secondary. The cathode active material mixture is reacted with a reductive reaction gas to form a preliminary precursor mixture having a reduction degree of transition metal defined by Equation 1 in a range from 0.24 to 1.6. A lithium precursor is recovered from the preliminary precursor mixture. A lithium recovery ration is improved by adjusting the reduction degree of transition metal.

Method for recovering active metal of lithium secondary battery

In a method for recovering an active metal of a lithium secondary battery, a cathode active material mixture is prepared from a cathode of a lithium secondary battery. A first reductive process using a first reductive reaction gas and a second reductive process using a second reductive reaction gas that has a higher reaction source concentration than that of the first reductive reaction gas are performed sequentially and continuously to convert the cathode active material mixture into a preliminary precursor mixture. A lithium precursor is recovered from the preliminary precursor mixture. A lithium recovery ratio may be increased by a stepwise reduction while preventing an increase of heating value.

A method for isolating a lithium precursor according to an embodiment of the present disclosure includes preparing a preliminary precursor mixture including a preliminary lithium precursor and a preliminary transition metal precursor, mixing the preliminary precursor mixture and a precipitation liquid in a reactor to form a precursor mixture, and injecting a non-reactive gas into the precursor mixture. Accordingly, the lithium precursor can be isolated with high yield and high efficiency.

Method for isolating lithium precursor and system for isolating lithium precursor

A method of producing carbon nanotubes in a fluidized bed reactor includes preparing a carbon nanotube by supplying a catalyst and a carbon source to an interior of the fluidized bed reactor having an internal pressure of 0.5 barg to 1.2 barg (gauge pressure), thereby improving the yield and purity of carbon nanotubes.

Method of producing carbon nanotubes in fluidized bed reactor

Provided is a method of producing carbon nanotubes by supplying a catalyst and a carbon source to a fluidized bed reactor. The fluidized bed reactor has an expanded zone. A flow velocity (linear velocity) of a raw material supplied to the fluidized bed reactor is equal to or higher than a terminal velocity of an internal material in the fluidized bed reactor.

The present invention provides a method for preparing anhydrosugar alcohol, in which the reaction temperature in a vacuum reaction that converts sugar alcohol into anhydrosugar alcohol is controlled to two steps of temperature that is, a first-step low reaction temperature of 100 to 150&#xb0; C. and a second-step high reaction temperature of 151 to 240&#xb0; C., so that the selectivity for the intermediate product 1,4-sorbitan can be increased, thereby increasing the yield of anhydrosugar alcohol.

Method of preparing anhydrosugar alcohol by two-step reaction

The present invention relates to a method of producing anhydrosugar alcohol by dehydrating sugar alcohol at high pressure in the presence of a catalyst which is less acidic than a conventional sulfuric acid catalyst and which can suppress side reactions at high temperature. According to the present invention, anhydrosugar alcohol can be produced in a yield similar to that in a vacuum reaction.

Method for producing anhydrosugar alcohol by high-pressure reaction

The present invention relates to a method of producing and purifying a high-purity anhydrosugar alcohol in high yield by a simple process and apparatus, the method includes the steps of: allowing a sugar alcohol to react in the presence of an acid catalyst in a reactor, and, at the same time, evaporating a product of the reaction; cooling the evaporated product to remove water and obtain a crude anhydrosugar alcohol; and introducing the crude anhydrosugar alcohol into a melt crystallization process to obtain a high-purity anhydrosugar alcohol.

Efficient method for producing and purifying anhydrous sugar alcohol

The present invention relates to a method for producing anhydrosugar alcohol, and more particularly to a method of producing anhydrosugar alcohol using a solvent including at least two components that form an azeotrope with water at atmospheric pressure and that have significantly different boiling points. The method for producing anhydrosugar alcohol according to the present invention can increase the yield of anhydrosugar alcohol by efficiently controlling the reaction temperature by use of a solvent including at least two components that form an azeotrope with water at atmospheric pressure and that have significantly different boiling points.

Method for producing anhydrous sugar alcohol using azeotropic distillation

A method for producing anhydrosugar alcohol according to the present invention can increase the yield of anhydrosugar alcohol even in the absence of a catalyst or in the presence of a small amount of a transition metal salt catalyst by controlling the temperature of a high-temperature reaction, which converts sugar alcohol to anhydrosugar alcohol, in two steps, that is, a first low-temperature reaction step and a second high-temperature reaction step.

Method for preparing anhydrosugar alcohol using two-step hydrothermal reaction

The present invention provides a method for producing anhydrosugar alcohol, including: feeding sugar alcohol into a reactor and performing a dehydration reaction of the fed sugar alcohol to produce anhydrosugar alcohol; and supplying steam to the reactor to evaporate the produced anhydrosugar alcohol. According to the present invention, anhydrosugar alcohol can be produced in a high yield by increasing the specific surface area of reaction mother liquor and reducing the partial pressure of the product.

Method of producing anhydrosugar alcohol using steam

The present invention relates to a method for producing anhydrosugar alcohol using an organic additive having one hydroxyl group. The present invention makes it possible to prevent oligomers and polymers from being produced by polymerization of isosorbide during dehydration of sorbitol molecules, and thus solves problems, including a reduction in fluidity in a dehydration reactor, interference with the flow of fluids in the reactor and pipelines, and interference with stirrer operation, which occur due to the oligomers and polymers.

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Daejeon, South Korea

Sung Real Son