Method for preparing transitional metal ion Co modified adsorbent for purifying low-concentration phosphine

Abstract

The invention relates to a method for preparing transitional metal ion Co modified adsorbent which is used for purifying low-concentration phosphine and mainly used for removing low-concentration phosphine in industrial production tail gas, belonging to the technical field of application of adsorption separation technique in atmospheric pollution purification. The method comprises the following steps of: (1) carrying out ultrasonic washing and drying treatment to an adsorbing material carrier until a constant-weight carrier is formed; (2) selecting a soluble cobalt salt to carry out ultrasonic immersing modification to the pretreated adsorbent carrier; (3) washing and drying the immersed adsorbent carrier; and (4) roasting the dried adsorbent carrier, and reducing the temperature to room temperature. The adsorbent prepared in the invention is unnecessary to add accelerating agents, such as noble metals or high-contamination heavy metals and the like; when the adsorbent is used for adsorbing waste gas containing phosphine, the adsorption is conducted by the surface of the modified adsorbent; waste gas dephophorization can be realized after the adsorption is saturated; and the adsorption activity is higher within in a certain temperature range.

Description

1. Technical field [0001] The invention relates to a preparation method of a transition metal ion Co modified adsorbent for purifying low-concentration phosphine, which is mainly used for removing low-concentration phosphine in industrial production tail gas, and belongs to adsorption separation technology applied to air pollution purification technology field. 2. Technical background [0002] Phosphine gas is present in certain concentrations in the gases produced in the processes of yellow phosphorus preparation, magnesium powder preparation, sodium hypophosphite production, acetylene production, feed fermentation, grain fumigation, and semiconductor industry production. Direct discharge of phosphine gas in the tail gas into the atmosphere will cause environmental pollution and endanger human health. If the phosphine-containing tail gas, especially the yellow phosphorus tail gas rich in CO, is utilized, the catalyst will be poisoned due to the presence of phosphine gas, w...

AI Technical Summary

Problems solved by technology

[0005] The oxidation-reduction absorption method uses the reducing property of phosphine to react with a solution containing an oxidizing agent (such as sodium hypochlorite, potassium permanganate, sulfuric acid, hydrogen peroxide, phosphoric acid, etc.) to realize the purification of phosphine. Consumption of oxidant, dephosphorization efficiency is closely related to oxidant concentration, while the concentration of oxidant drops rapidly during the absorption reaction, so there are disadvantages such as high operating cost, easy fluctuation of dephosphorization efficiency, and poor operability of the device

Chinese patent CN 85105317 (publication number) has reported the method for washing out phosphine from acetylene gas, and this method uses 70% phosphoric acid solution, but this method flow process is complicated, and gas needs to pass through lime milk scrubber pretreatment, also needs consumption The scrubbing acid is regenerated with pure oxygen and no mention is made of the residual concentration of phosphine after scrubbing

[0006] Chinese patent CN 1398658A (publication number) discloses a method for purifying yellow phosphorus tail gas by catalytic oxidation in a fixed bed, and develops a series of catalysts for catalytic adsorption of pH 3 Impurities, the principle is to use PH 3 The strong reducibility of the activated carbon reacts with the active components on the activated carbon to form P 2 o 3 and P 2 o 5 , and using P 2 o 3 and P 2 o 5 The adsorption capacity is much greater than that of pH 3 This feature is used to realize the deep purification of yellow phosphorus tail gas. The disadvantage is that oxygen or air needs to be strictly quantitatively added to the yellow phosphorus tail gas, which increases the difficulty of operation and control, and due to the P 2 o 3 and P 2 o 5 The strong adsorption capacity on activated carbon makes it difficult to regenerate activated carbon after adsorption saturation, that is, there are problems such as the need for subsequent treatment of activated carbon containing phosphorus

In the pressure swing temperature swing adsorption process, the dephosphorization effect and the regeneration of the adsorbent have been studied, and the experimental effect is good, but the regeneration process is to use nitrogen with oxygen content of 0.01% to 5% or a part of the purified gas as the regeneration gas while making phosphorus The phosphine component is oxidized, and the resource utilization of phosphine gas itself cannot be realized