The Study Of Preparation And Synthesis Of Ethanol Of Cu-Zn-Al Catalyst By Complete Liquid-phase Technology

Fossil fuel consumption, crude oil prices soaring and concerning aboutglobal warming make rapid development of clean energy markets. Ethanol as animportant clean energy has been widely used as gasoline additives or potentialgasoline substitutes. It can improve the octane value of the gasoline andcombustion efficiency of car engine, at the same time reduce the emission ofenvironmental pollutants and greenhouse gases, which has caused the scholarsextensive concern. As our country has rich coal resources, coal-based syngascatalyze to produce ethanol has important strategic and practical significance.Our group research used the domestically developed completely liquidtechnology to prepare Cu-Zn-Al catalyst, in the process of methanol synthesis,we found that catalyst has higher selectivity of ethanol, but the reproducibility ispoor, therefore we put forward this topic to research a Cu-Zn-Al catalyst whichhas high reactive and high ethanol selectively. On the base of our team’s former studies, this article inspected the effect of raw materials of catalystpreparation, the Cu and Zn precursor properties, heat treatment and reactionmedium on the catalytic performance; And we combined solvothermalpreparation method and completely liquid technology to prepare catalysts,inspected the effect of surfactant on the catalytic performance; The Cu-basedcatalysts for ethanol were evaluated in a slurry reactor and characterized byXRD, H2-TPR, NH3-TPD, N2-adsorption, XPS, TEM, and we combined thecharacterization results and activity data to get the the following conclusions:1. The Cu-Zn-Al catalyst with high ethanol selectivity has thefollowing characteristics: smaller particle size and better dispersion;the existence of anti-reducibility Cu+; the low surface carbon content; a smallamount of medium strong acid sites; more macropores.2. The acetate radical of catalyst which used acetate as raw materials canreact with hydrogen to generate ethanol, and affect the judgement of catalystperformance.3. The Cu-Zn-Al catalyst which prepared by ammonia as copper zincsalt’s complexing agent can reduce the grain size of Cu0.4. PEG-200as heat medium can improve the specific surface area ofcatalysts, PEG-200as reaction mediumis can participate in the reaction ordecompose to generate ethanol at reaction temperature (250℃), and influencethe result of experiment.5. PEG-400as heat medium is helpful to improve the specific surface area of catalysts, reduce the carbon content on the catalyst surface, improve thesurface copper content, the existence of anti-reducibility Cu+in the catalyst isconducive to form the synergy between Cu+and Cu0.6. PEG-400as reaction medium can inhibit the grain size of copper growthin the reaction, improve the selectivity of ethanol and C5hydrocarbon, butstructure and surface composition of catalyst have great changes.7. The catalyst prepared by completely-liquid-solvothermal technology hassmaller particle size and better dispersion, but the structure is not stable andeasily inactivated; It also has low reproducibility.