Abstract: A carbon dioxide absorbent is disclosed. The absorbent comprises organic amine, amino acid, and water, wherein said organic amine comprises tertiary amine and primary amine and/or secondary amine; and wherein amino acid is excess based on a stoichiometrical ratio of organic amine to amino acid in a reaction. A method for absorbing and desorbing carbon dioxide is further disclosed. In the absorbent system provided by the present disclosure, the conversion between primary (secondary) amine and (secondary) tertiary amine can be realized under the catalytic effect of amino acid with the changing of temperature, and carbon dioxide can be absorbed and desorbed effectively under a relatively low temperature.

Abstract: Disclosed is a method for preparing a copper-zinc-based catalyst used in synthesis of methanol through CO2 hydrogenation, and ultrasonic waves are used for control over crystalline phase's composition of a catalyst precursor. Further related to is a catalyst prepared by such a method. An amount of aurichalcite in an active catalyst precursor can be improved through the method, and the specific surface area of the metal copper in a reduced state catalyst is high. The catalyst presents high activity and hydrothermal stability, and promotes high space time yield of methanol in the synthesis of methanol through CO2 hydrogenation.

Abstract: The present invention discloses a hydrogenation catalyst comprising metallic palladium supported on activated carbon support, wherein the penetration depth of metallic palladium in the support is at least about 10 ?m and up to about 100 ?m, the crystallite size of palladium is between about 40 ? and about 120 ?, and the palladium in the surface layer from the surface of support to a depth of 1 ?m is from about 5% to about 40% based on the total atom number of palladium and other elements. The present invention further discloses a process for preparing the hydrogenation catalyst, and a use of said hydrogenation catalyst in the purification of crude terephthalic acid.