Flue gas treatment method for realizing desulphurization and denitrification simultaneously by using lanthanum-cerium oxide-loaded titanium dioxide nanotube array for catalytic reduction

Abstract

The invention provides a flue gas treatment method for realizing desulphurization and denitrification simultaneously by using lanthanum-cerium oxide-loaded titanium dioxide nanotube array for catalytic reduction. The method takes a titanium dioxide nanotube array as a catalyst carrier, and a catalyst is prepared by doping the catalyst carrier with lanthanum oxide and cerium oxide; the method comprises the steps of enabling mixed gas of carbon monoxide and flue gas containing sulfur dioxide or nitrogen oxide (nitric oxide and nitrogen dioxide) to pass through the catalyst at the temperature of 500 DEG C so as to enable the sulfur dioxide and the nitrogen oxide to respectively have catalytic reduction reaction with the carbon monoxide, wherein the sulfur dioxide is transformed into sulfur by means of reduction, cooling and then recovering the elemental sulfur, and the nitrogen oxide is transformed into nitrogen by means of reduction, absorbing the tail gas by using alkaline liquor and then recovering the nitrogen. After the method is adopted, not only are the aims of realizing desulphurization and denitrification at the same time achieved, but high added-value products, i.e., the elemental sulfur and the nitrogen are also recovered, and the tail gas also can reach the current emission standard. After the method is adopted, the desulphurization efficiency is 96% or above, the denitrification efficiency is 99.9% or above, the elemental sulfur recovery rate is 97% or above, and the N2 recovery rate is 98% or above.

Description

technical field [0001] The invention belongs to the field of environmental protection science, and relates to a flue gas treatment method for catalytic reduction of titanium dioxide nanotube arrays loaded with lanthanum cerium oxide and simultaneous desulfurization and denitrification. Background technique [0002] At present, simultaneous desulfurization and denitrification technologies are divided into two categories: (1) Selective catalytic reduction method: using reducing agents CO, H 2 , NH 3 and CH 4 Etc to reduce SO 2 and NOx are elemental sulfur and N, respectively 2 , to achieve desulfurization and denitrification; (2) Oxidation method, using an oxidant to oxidize water-insoluble NO to generate NO 2 , thus with SO 2 At the same time, it is absorbed in the lye in the later stage to achieve the purpose of desulfurization and denitrification. The oxidant of the oxidation method is expensive, the equipment requirements are relatively high, and the oxidation produc...

AI Technical Summary

Problems solved by technology

Using this method can achieve the purpose of catalytic desulfurization and denitrification at the same time, and can recover high value-added products elemental sulfur and nitrogen, and can also ensure the conversion rate of sulfur dioxide and nitrogen oxides in the flue gas and the recovery rate of product elemental sulfur and nitrogen. Difficult preparation of catalysts in the prior art and difficulties in separation and recovery of by-products

Images