Catalyst for preparing ethanol by acetic acid gas phase hydrogenation and preparation method thereof

Abstract

The invention discloses a catalyst for preparing ethanol by acetic acid gas phase hydrogenation and a preparation method thereof. The catalyst comprises active components, an auxiliary agent, and a carrier, wherein the active components comprise iron and tin; the auxiliary agent is one of platinum, palladium and ruthenium; the carrier is a composite carrier of alumina and titanium dioxide, or one or more of silica, alumina and calcium silicate; the weight of the active components is 1 to 20% of the total weight of the catalyst; and the weight of the auxiliary agent is 0.25 to 1% of the total weight of the catalyst. The preparation method of the catalyst comprises the following steps of 1, dissolving precursors of iron and tin in a solution of a water-soluble solvent, and loading the precursor solution on the selected carrier, 2, carrying out calcination in a muffle furnace, 3, preparing a precursor of platinum, palladium or ruthenium into an aqueous solution, dipping the catalyst precursor loaded with iron and tin into the aqueous solution, wherein the volume of the catalyst precursor is the same as that of the aqueous solution, standing, drying to constant weight in a muffle furnace, and carrying out calcination, and 4, carrying out reduction before catalyst use. The catalyst obtained by the preparation method has low precious metal content. Through the catalyst, products mainly comprise ethanol and ethyl acetate; reaction conditions are mild; and energy consumption is low.

Description

technical field [0001] The invention relates to the technical field of catalysts and their preparation, in particular to a catalyst for preparing ethanol by gas-phase hydrogenation of acetic acid and a preparation method thereof. Background technique [0002] Ethanol, commonly known as alcohol, is a flammable and volatile colorless transparent liquid at normal temperature and pressure. Ethanol in water has a characteristic, pleasant aroma and is slightly irritating. Ethanol can be produced from starchy agricultural products, such as cereals, potatoes or wild plant fruits, or from waste molasses from sugar factories, cellulose-containing sawdust, plant stems, etc. Therefore, ethanol is a renewable raw material. Medically, 70% to 75% ethanol is commonly used as a disinfectant. Ethanol is widely used in industry. In addition, oil products improved with ethanol (ethanol gasoline, according to my country's national standards, ethanol gasoline is blended with 90% of ordinary g...

AI Technical Summary

Problems solved by technology

[0009] U.S. Patent No. 5,149,680 discloses "a process for the hydrogenation of carboxylic acids and carboxylic anhydrides catalyzed by Pt metal alloys". The catalyst mainly contains Group VIII noble metals and a metal that can form alloys with them, plus Ru, W or Mo The temperature of the process is about 300°C and the pressure is about 1Mpa; however, 3-9% of by-products methane and ethane are still produced under the condition of using the optimal catalyst

[0010] To sum up, the existing methods have some deficiencies, or the selectivity of ethanol is not high, and there are undesirable by-products; or the noble metal loading used is large, and the cost is high