Cellulosic ethanol wastewater treatment catalyst, preparation method thereof and wastewater treatment method

Abstract

The invention relates to a cellulosic ethanol wastewater treatment catalyst, a preparation method of the catalyst and a wastewater treatment method. Nanometer TiO2 is used as a carrier in the cellulosic ethanol wastewater treatment catalyst; the cellulosic ethanol wastewater treatment catalyst contains the following active components in parts by mass: 0.35-0.8% of precious metal element and 1-10% of rare-earth metal element, wherein the precious metal element is one or more than one of Pt, Pd, Ru and Rh, the rare-earth metal element used as an assistant is one or more than one of La, Ce, Pr and Nd, and the mass ratio of the rare-earth metal element to the precious metal element is 3-15. The catalyst provided by the invention is used in the cellulosic ethanol wastewater catalytic wet oxidation treatment process and has the advantages of high catalytic activity, low reaction temperature and the like.

Description

technical field [0001] The invention relates to a catalyst for the treatment of fiber ethanol wastewater and its preparation method and application, in particular to a catalyst for the treatment of fiber ethanol wastewater by catalytic wet oxidation, as well as its preparation method and application. Background technique [0002] Cellulose ethanol is produced through pretreatment and fermentation of fibers such as straw and crops as raw materials. Due to the complex production process of cellulosic ethanol, the production water and drainage are very high, and the wastewater generated in the process is a kind of organic wastewater with high concentration, high suspended solids and high salt content, which is generally acidic and is the main source of pollution in the ethanol industry. Therefore, the treatment of cellulosic ethanol wastewater has become a key factor limiting the large-scale production of cellulosic ethanol. [0003] At present, the treatment methods of organi...

AI Technical Summary

Problems solved by technology

For high-concentration cellulosic ethanol wastewater, the common problem with biological methods is that the wastewater needs to be diluted to a lower concentration before it can be treated. The activated sludge method needs to further treat the sludge, which increases the cost investment, while the bacteria in the anaerobic method The class is sensitive to changes in conditions such as temperature and is difficult to control

[0005] CN1292304A discloses "Rare Earth-based Supported Catalyst Used in Wet Oxidation and Its Preparation Method", which provides a Ti-Ce-Bi non-precious metal catalyst and its preparation method for catalyzing wet oxidation, in order to reduce catalyst cost, but the The reaction temperature required by the catalyst is relatively high, and the acetic acid removal rate reaches 96% after the acetic acid model reaction at 230 ° C for one hour

However, the reaction temperature and pressure are high, and the preparation process of carbon material catalysts is relatively complicated, which is not conducive to the industrial application of catalysts.

[0009] CN1669643A discloses "rare earth composite oxide catalyst in catalytic wet oxidation process and its preparation method", which provides a solid powder ZrO 2 and CeO 2 The composite oxide catalyst and the preparation method thereof, the catalyst has good activity for the organic waste water containing high concentration and refractory small molecules, and the dissolution amount of metal ions is very small, but the catalyst can remove COD when the total pressure is 5MPa at 230°C The rate reaches 87%, the reaction temperature and pressure are high, the investment cost is large, and the powder catalyst is not conducive to industrial application

But its noble metal loading is 1~3wt%, it is difficult to reduce the catalyst cost

[0012] The "wastewater wet oxidation treatment catalyst and its preparation method" disclosed by CN102039128A mainly solves the problems of biological inhibition, low COD removal rate and complicated process during the treatment of sulfur-containing wastewater or the inability to simultaneously treat other organic compounds in the wastewater during the treatment of cyanide-containing wastewater. Pollutants and Secondary Pollution Issues

However, the treatment effect of this catalyst is not ideal when it is used in the treatment of cellulosic ethanol wastewater, indicating that its catalyst composition is not suitable for the treatment of cellulosic ethanol production wastewater

[0014] Wastewater from cellulosic ethanol production has the characteristics of complex components, high solid solution content, and high salt content. When using existing wet oxidation catalysts, either the effect is not ideal, or the reaction conditions are relatively harsh, or noble metal catalysts with high noble metal content are required. , cost increase