Regeneration method of inactivated gold-based catalyst

Abstract

The invention discloses a regeneration method of an inactivated gold-based catalyst, which specifically comprises the following steps: roasting the inactivated gold-based catalyst for acetylene hydrochlorination reaction in an inert gas atmosphere, washing, filtering, drying, impregnating with a thiosulfate solution, and carrying out heat treatment to obtain a regenerated catalyst; according to the method disclosed by the invention, the performance of the inactivated gold-based catalyst can be effectively improved, so that the preparation and use cost of the catalyst is reduced, and the method has important significance on industrial application of the gold-based catalyst.

Description

TECHNICAL FIELD

[0001] The present application relates to a regeneration method of inactivated gold-based catalyst, belonging to the field of catalytic regeneration. BACKGROUND

[0002] Polyvinyl chloride (PVC) material is widely used in construction, pharmaceutical, electrical engineering and other fields, and has become the third largest polymer in the world; PVC has the advantages of high aging resistance, light degradation resistance and non-toxicity; the main industrial production methods of its monomer vinyl chloride (VCM) include acetylene method and ethylene method; the acetylene method is more suitable for the areas where coal resources are abundant and economical, but the resources of petroleum and natural gas are relatively scarce; in industry, the core of acetylene hydrochlorination method is mercury-based catalyst (mercury / carbon, abbreviated as Hg / C), and mercury, as a volatile toxic chemical, can cause serious harm to human health and natural environment; the Minamata Convention on Mercury was formally implemented in 2017, and the use of mercury has been prohibited by order; therefore, it is urgent to find other high-efficiency mercury catalyst substitutes.

[0003] At present, gold-based catalyst is the most potential catalyst, which has the advantages of high selectivity and not easy to lose, but Au-based catalyst has a serious deactivation problem; in view of this problem, the present application provides a regeneration method of inactivated catalyst, compared with the existing regeneration method, the regeneration method can significantly improve the activity of the catalyst, and improve the utilization rate of the active component of the catalyst. SUMMARY

[0004] The present application discloses a regeneration method of inactivated gold-based catalyst, which can significantly improve the performance of inactivated gold-based catalyst, and is expected to reduce the preparation cost and use cost of the catalyst, and has a major guiding significance for the industrial application of gold-based catalyst; specifically including the following steps: (1) calcining the catalyst to be regenerated in an inert gas atmosphere.

[0005] (2) washing, filtering and drying the calcined catalyst using a solvent.

[0006] (3) immersing the dried catalyst in a thiosulfate solution for a period of time.

[0007] (4) drying the immersed catalyst to obtain a regenerated catalyst.

[0008] Preferably, the content of the active component gold in the catalyst to be regenerated in step (1) of the regeneration method is 0.01-5wt%, and wt% is mass fraction.

[0009] Preferably, the inert gas in step (1) of the regeneration method is selected from one or more of nitrogen, argon and helium, and the calcination device adopts one of a tubular furnace, a moving bed and a box furnace.

[0010] Preferably, the calcination temperature in step (1) of the regeneration method is 100-500℃, and the calcination time is 0.5-24 hours.

[0011] Preferably, the washing liquid in step (2) of the regeneration method is one or more of water, ammonia, EDTA, ethylenediamine, ethanol, sodium hydroxide, and potassium hydroxide.

[0012] Preferably, the drying temperature in step (2) of the regeneration method is 50-120℃, and the drying time is 3-24 hours.

[0013] Preferably, the concentration of the thiosulfate solution in step (3) of the regeneration method is 0.01-2.5 mol / L, and the pH range is 6-10.

[0014] Preferably, the liquid-solid ratio of the thiosulfate solution to the deactivated gold-based catalyst in step (3) of the regeneration method is 1:1-100:1 (mL:g), and the impregnation time is 0.5-48 hours.

[0015] Preferably, the impregnation temperature in step (3) of the regeneration method is 25-80℃.

[0016] Preferably, the drying temperature in step (4) of the regeneration method is 60-150℃, and the drying time is 1-24 hours.

[0017] The present application has the following advantages: 1. The main reason for the deactivation of gold catalysts is the agglomeration of gold particles on the surface and the reduction of combined gold to low-valence gold, and the method of the present application can restore the gold valence and improve the dispersion performance, so it has wide applicability in improving the performance of catalysts.

[0018] 2. The method of the present application is simple to operate, and the main reagent used is thiosulfate, which is used in a weak alkaline environment and does not corrode equipment, and can be used as a soil fertilizer, so the present application has the characteristics of safe operation, environmental protection, etc.

[0019] 3. The catalyst treated by the method of the present application has the possibility of being applied to other reactions in addition to the ethylene hydrochlorination reaction. DETAILED DESCRIPTION

[0020] The present application will be further described in detail below with reference to specific examples, but the scope of protection of the present application is not limited to the described content; the wt% involved in the examples of the present application is mass fraction.

[0021] Example 1 Take 1 g of 5wt% gold deactivated carbon catalyst, in a tube furnace, nitrogen atmosphere, with a temperature rising rate of 10 ℃ / min, heated to 500 ℃, constant temperature for 0.5 h, to obtain the calcined sample.

[0022] The calcined catalyst is washed with ethanol and filtered out, dried at 120 ℃ for 3 h.

[0023] Take 1 mL of 2.5 mol / L sodium thiosulfate solution, impregnate the dried sample at 25 ℃ (liquid-solid ratio is 1 mL:1 g), solid-liquid separation after 8 h, dry at 60 ℃ for 12 h after impregnation, to obtain the regenerated catalyst.

[0024] Put the obtained catalyst into the catalytic reaction evaluation device to evaluate the catalytic performance of acetylene hydrochlorination, and the conversion rate of acetylene is 85%.

[0025] Example 2 Take 1 g of 2wt% gold deactivated carbon catalyst, in a tube furnace, helium atmosphere, with a temperature rising rate of 10 ℃ / min, heated to 400 ℃, constant temperature for 6 h, to obtain the calcined sample.

[0026] The calcined catalyst is washed with sodium hydroxide solution and filtered out, dried at 50 ℃ for 24 h.

[0027] Take 2 mL of 0.5 mol / L sodium thiosulfate solution, impregnate the dried sample at 80 ℃ (liquid-solid ratio is 2 mL:1 g), solid-liquid separation after 12 h, dry at 60 ℃ for 24 h after impregnation, to obtain the regenerated catalyst.

[0028] Put the obtained catalyst into the catalytic reaction evaluation device to evaluate the catalytic performance of acetylene hydrochlorination, and the conversion rate of acetylene is 72%.

[0029] Example 3 Take 1 g of 0.1wt% gold deactivated carbon catalyst, in a tube furnace, argon atmosphere, with a temperature rising rate of 10 ℃ / min, heated to 300 ℃, constant temperature for 12 h, to obtain the calcined sample.

[0030] The calcined catalyst is washed with water and filtered out, dried at 80 ℃ for 12 h.

[0031] Take 100 mL of 0.01 mol / L sodium thiosulfate solution, impregnate the dried sample at 50 ℃ (liquid-solid ratio is 100 mL:1 g), solid-liquid separation after 48 h, dry at 150 ℃ for 8 h after impregnation, to obtain the regenerated catalyst.

[0032] Put the obtained catalyst into the catalytic reaction evaluation device to evaluate the catalytic performance of acetylene hydrochlorination, and the conversion rate of acetylene is 35%.

[0033] Example 4 Take 1 g of 0.01 wt% deactivated gold-carbon catalyst and calcine it in a box furnace under a nitrogen atmosphere. The temperature is increased to 100℃ at a rate of 10℃ / min and held at the temperature for 24 hours to obtain the calcined sample.

[0034] The calcined catalyst was washed with a mixture of ammonia and ethylenediamine and then filtered out and dried at 100°C for 24 hours.

[0035] Take 5 mL of 1 mol / L sodium thiosulfate solution and impregnate the dried sample at 25 °C (liquid-solid ratio of 5 mL: 1 g). After 24 h, the solid and liquid are separated. After impregnation, the sample is dried at 120 °C for 12 h to obtain the regenerated catalyst.

[0036] The obtained catalyst was placed in a catalytic reaction evaluation device to evaluate the catalytic performance of acetylene hydrochlorination. The conversion rate of acetylene was 28%.

[0037] Example 5 Take 1 g of deactivated 1wt% gold-carbon catalyst and calcine it in a tube furnace under a helium atmosphere. The temperature is increased to 200℃ at a heating rate of 10℃ / min and held at that temperature for 18 hours to obtain the calcined sample.

[0038] The calcined catalyst was washed with EDTA, filtered, and dried at 100°C for 18 hours.

[0039] Take 2 mL of 0.5 mol / L sodium thiosulfate solution and impregnate the dried sample at 40 °C (liquid-solid ratio of 2 mL: 1 g). After 8 h, the solid and liquid are separated. After impregnation, the sample is dried at 150 °C for 6 h to obtain the regenerated catalyst.

[0040] The obtained catalyst was placed in a catalytic reaction evaluation device to evaluate the catalytic performance of acetylene hydrochlorination, and the conversion rate of acetylene was 68%.

[0041] Example 6 Take 1 g of deactivated 3wt% gold-carbon catalyst and calcine it in a moving bed under a nitrogen atmosphere. The temperature is increased to 250℃ at a heating rate of 10℃ / min and held at that temperature for 20 hours to obtain the calcined sample.

[0042] The calcined catalyst was washed with potassium hydroxide solution, filtered, and dried at 80°C for 6 hours.

[0043] Take 2 mL of 0.5 mol / L sodium thiosulfate solution and impregnate the calcined sample at 25 °C (liquid-solid ratio of 2 mL: 1 g). After 8 h, the solid and liquid are separated. After impregnation, the sample is dried at 120 °C for 8 h to obtain the regenerated catalyst.

[0044] The obtained catalyst was placed in a catalytic reaction evaluation device to evaluate the catalytic performance of acetylene hydrochlorination, and the conversion rate of acetylene was 76%.

[0045] Comparative Example 1 1 g of activated carbon was washed with deionized water to remove powder dust, filtered, and then taken out after drying in an 80℃ oven for 12 h for standby use.

[0046] 5 mL of HAuCl4 solution (solvent: water) was used to impregnate the above-mentioned original activated carbon (liquid-solid ratio: 5 mL: 1 g), and after 8 h of solid-liquid separation, the active component loading was calculated to be 1%, and the activated carbon after impregnation was dried at 60℃ for 12 h to obtain the catalyst.

[0047] The obtained catalyst was placed in a catalytic reaction evaluation device to evaluate the catalytic performance of acetylene hydrochlorination, and the conversion rate of acetylene was 5%, which was an inactivated gold-based catalyst.

[0048] Comparative Example 2 1 g of activated carbon was washed with deionized water to remove powder dust, filtered, and then taken out after drying in an 80℃ oven for 12 h for standby use.

[0049] 5 mL of HAuCl4 solution (solvent: 6 mol / L HCl) was used to impregnate the above-mentioned original activated carbon (liquid-solid ratio: 5 mL: 1 g), and after 8 h of solid-liquid separation, the active component loading was calculated to be 1%, and the activated carbon after impregnation was dried at 60℃ for 12 h to obtain the catalyst.

[0050] The obtained catalyst was placed in a catalytic reaction evaluation device to evaluate the catalytic performance of acetylene hydrochlorination, and the conversion rate of acetylene was 3%, which was an inactivated gold-based catalyst.

[0051] From the comparison between the comparative examples and the embodiments, the conversion rate of acetylene of the inactivated catalyst increased significantly, and the regeneration method was effective.

[0052] The specific embodiments of the present application are described in detail above, but the present application is not limited to the above-mentioned embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the present application.

[0053] The acetylene hydrochlorination catalytic performance evaluation method and conditions: the catalyst was placed in a reaction tube, purged with N2, and then activated with HCl gas at 180℃ for 30 min, and then adjusted to the corresponding ratio according to V C2H2 :V HCl =1:1.15, the acetylene space velocity was GHSV=1200h -1 , and the gas after the reaction was analyzed by gas chromatography to obtain the conversion rate of acetylene.

Claims

1. A method for regenerating a deactivated gold-based catalyst, the regeneration method comprising the following: (1) The catalyst to be regenerated is calcined in an inert gas atmosphere; (2) The calcined catalyst is washed, filtered, and dried using a solvent; (3) Add the dried catalyst to the thiosulfate solution and impregnate it for a period of time; (4) The impregnated catalyst is dried to obtain a regenerated catalyst.

2. The regeneration method according to claim 1, characterized in that: In step (1), the content of gold, the active component in the catalyst to be regenerated, is 0.01 to 5 wt%, where wt% is the mass fraction.

3. The regeneration method according to claim 1, characterized in that: In step (1), the inert gas is selected from one or more of nitrogen, argon, and helium.

4. The regeneration method according to claim 1, characterized in that: In step (1), the roasting temperature is 100-500℃ and the roasting time is 0.5-24 hours.

5. The regeneration method according to claim 1, characterized in that: The washing liquid in step (2) is one or more of the following: water, ammonia, EDTA, ethylenediamine, ethanol, sodium hydroxide, and potassium hydroxide.

6. The regeneration method according to claim 1, characterized in that: In step (2), the drying temperature is 50-120℃ and the drying time is 3-24h.

7. The regeneration method according to claim 1, characterized in that: In step (3), the concentration of the thiosulfate solution is 0.01–2.5 mol / L, and the pH range is 6–10.

8. The regeneration method according to claim 1, characterized in that: In step (3), the liquid-solid ratio of thiosulfate solution to deactivated gold-based catalyst is 1:1 to 100:1, with units of mL:g, and the immersion time is 0.5 to 48 h.

9. The regeneration method according to claim 1, characterized in that: The immersion temperature in step (3) is 25-80℃.

10. The regeneration method according to claim 1, characterized in that: In step (4), the drying temperature is 60-300℃ and the drying time is 1-24h.