SU1209274A1 - Method of reactivation of catalyst for cleaning gas from phosphine - Google Patents

Description

The invention relates to the field of reactivation of heterogeneous catalysts, in particular catalysts containing nickel oxide on a carrier — activated carbon and used, for purifying gas from phosphine.

The purpose of the invention is to restore the catalyst activity to the original level by first treating the catalyst with phosphoric acid solution, then with air under certain conditions.

Example 1. A freshly prepared catalyst containing 15% Ni O and 85% activated carbon is used in the process of purifying gas from phosphine. After 150 hours of his work, as a result of poisoning the catalyst with phosphorus compounds, mainly phosphoric anhydride, its activity decreases by 50%.

Place 5 g of spent catalyst in the reactor and feed a 7% phosphate solution with a dosing pump at a volume rate of 2 hours. After that, air is passed through the reactor at 115 ° C for 20 minutes. The activity of the reactivated catalyst is determined by the process of gas purification from phosphine.

For this purpose it is placed in a tubular reactor with a diameter of 10 mm and a gas-air mixture containing 100 mg / m of phosphine and 16% oxygen is passed through it. The process is conducted at room temperature and a gas flow rate of 11,000 hours.

The degree of gas purification from phosphine is monitored every 10 hours. After 120 hours of continuous operation, it is 100%.

Example 2: Conditions are similar. 1. The difference is the concentration of phosphate solution.

The effect of concentration on the restoration of catalyst activity, expressed in the powers of gas purification from phosphine, is presented in Table. one.

phosphate cleaning

95.6 97.4

100

0

9

five

0

five

0

five

0

five

0

2742

From the data table. 1, it follows that when the concentration of the phosphoric acid solution is 5–9%, the catalyst activity is restored to its original value. A change in the concentration of the phosphate solution in the direction of an increase or decrease does not allow for complete recovery of the activity.

Example 3. Conditions are similar to example 1. Difference - the temperature of the air supplied to the reactor.

The effect of the temperature of catalyst heat treatment with oxygen in the air on the restoration of its activity is presented in Table. 2

From the data table. 2, it can be seen that the optimum temperature for heat treatment of the catalyst with oxygen of the air should be IIO-ISO C, at which the activity of the catalyst is restored to the original level. Lowering the temperature does not lead to a complete restoration of the activity of the catalyst, and an increase is impractical because it is associated with high energy consumption.

Example 4. Conditions are similar to example 1.

The difference is the volumetric feed rate of the phosphate solution, the effect of which on the restoration of catalyst activity is given in Table. 3

From the results presented in table. 3, it can be seen that the activity of the treated catalyst is completely restored at a volume rate of its washing with a phosphate solution of at least 2 hours. Decreasing this speed does not lead to the restoration of catalyst activity to the level of the initial one.

Example 5.-Conditions are similar to Example 1. The difference is the time for purging the spent catalyst with oxygen from the air.

The change in the activity of the catalyst depending on the time of its treatment with air oxygen is shown in Table 4

Table 1

100 100 100 100 97.7

95.9

The degree of purification of gas from phosphine,

90 98, A 100 100 100 100 100

The degree of purification of gas from phosphine,%

95,897,9

The time of treatment of the catalyst with air, min

15

The degree of purification of gas from phosphine,%

96.9

Compiled by V. Teplov. Editor N. Tupitsa Tehred A.Ach.Corrector M. Demchik

Order 346/12

Circulation 527

VNIIPI State Committee of the USSR

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Branch PPP Patent, Uzhgorod, st. Project, 4

table 2

100

100,100

Table 4

20

25

thirty

100

100

100

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Claims (1)

METHOD OF REACTIVING THE CATALYST FOR GAS CLEANING FROM PHOSPHINE, containing nickel oxide on an activated carbon carrier, characterized in that, in order to restore the activity of the catalyst to the initial level, the catalyst is treated first with a 5-9% phosphoric acid solution with a volumetric flow rate of solution 2 , 0-2.5 h ^{_ <} , then with air at 110-130 C for 20-25.min.