Sk Innovation Co., Ltd.

Sk Global Chemical Co., Ltd.

Suk Joon Hong

Tae Jin Kim

Sung Real Son

In Hyoup Song

Yoon Jae Yim

Ji Min Kim

Tae Seung Kim

Dae Hyun Choo

Sang Hye Shin

Yong Tak Kwon

Min Ji Sung

Dong Wook Ha

Young Bo Choi

Ji Yun Park

Hyeon Bae Ha

Tae Jln Kim

Hwa Jung Lee

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.

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 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 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.

Method of preparing anhydrosugar alcohol using additive for prohibiting polymerization by dehydration

Disclosed herein is a method of preparing a catalyst having Pt&#x2014;Pd dispersed in polymer electrolyte multilayers, suitable for use in production of hydrogen peroxide, wherein the use of the catalyst prepared by forming polymer electrolyte multilayers on an anionic resin support and performing sulfuric acid treatment and loading (insertion or attachment) of Pt&#x2014;Pd particles can result in high hydrogen conversion, hydrogen selectivity and hydrogen peroxide yield for a long period of time.

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Daejeon, South Korea

Suk Joon Hong