CN104941663A - Preparation method of high acid content solid acid catalyst - Google Patents

Abstract

The invention discloses a preparation method of a high-acid solid acid catalyst. The method uses plant waste as raw material. Firstly, the plant waste is dried, crushed and sieved, added to concentrated sulfuric acid under stirring and mixed uniformly, and then heated at room temperature Dehydration and carbonization for 10-24 hours, further sulfonation at 100-200°C for 15-30 hours to obtain a solid mixture; wash the mixture with hot water to remove the residual liquid acid in the solid mixture, and filter and dry the washed solid Dry and pulverize to obtain a solid acid catalyst; the acidity of the obtained solid acid is 3.5 to 5.0 mmol/g, and the solid acid catalyst is called GDUT-1; the preparation method of the present invention is simple and feasible, and the GDUT-1 solid prepared by this method is The acid catalyst has the characteristics of high acid content, good catalytic activity, recyclable utilization, green environmental protection, etc., and has low preparation cost, and is suitable for industrial production.

Description

A kind of preparation method of high acid content solid acid catalyst

technical field

The invention belongs to the technical field of solid acid catalysts, and in particular relates to a preparation method of a high acid content solid acid catalyst.

Background technique

In the production of modern chemical industry, acid catalyst occupies a very important position. Liquid acid catalysts such as sulfuric acid, hydrochloric acid, phosphoric acid, hydrofluoric acid, p-toluenesulfonic acid, etc. are widely used in chemical production because of their good catalytic performance and low price. , but there are shortcomings such as serious corrosion to equipment, difficulty in repeated recycling, difficulty in separation from reactants and products, and large discharge of three wastes, which have caused serious negative effects on human health, work and living environment.

With the enhancement of people's awareness of environmental protection and the introduction of the concept of green chemistry, the development of solid acid catalysts that take into account the environment and realize the clean production of chemical industrial products has become an internal demand for the sustainable development of the chemical industry. Compared with liquid acid catalysts, solid acid catalysts have the advantages of easy separation of catalysts, raw materials and products, recyclable reuse, no corrosion of reaction equipment, and no pollution to the environment. Among them, biomass solid acid catalyst has become a research hotspot in the field of catalyst preparation due to its good catalytic performance, low cost, and effective utilization of resources. (>350°C) under the protection of an inert atmosphere for incomplete carbonization, and then sulfonate it with concentrated sulfuric acid or fuming sulfuric acid. This method is relatively complicated to operate, requires high temperature, inert atmosphere and other preparation conditions, and the prepared solid acid catalyst has a small specific surface area, serious damage to the original structure, and low surface acid content and is easy to lose. For example, Chinese invention patent application CN104475127A reports that pineapple pomace is used to make activated carbon, and then the prepared activated carbon is used to prepare a solid acid catalyst, which needs to be activated at a high temperature of 450-500°C. It can be seen that the existing biomass solid acid preparation process is difficult to be used in large-scale industrial production, so there is an urgent need to improve the preparation process and use a simple method to synthesize a solid acid catalyst with high acid content, stable structure, and suitable for industrial production , so as to realize the purpose of using this kind of catalyst in the clean production of chemical industrial products.

Contents of the invention

The technical problem that the present invention solves is to provide a kind of preparation method of solid acid catalyst with high acid content, the solid acid surface acidity that utilizes this method to make is 3.5～5.0mmol/g, and this solid acid catalyst is called GDUT-1, has low Low cost, high acid content, simple and efficient, suitable for industrial production.

For realizing above-mentioned technical goal, the technical scheme that the present invention adopts is:

A preparation method of a high-acid solid acid catalyst, the method uses plant waste as raw material, first adds concentrated sulfuric acid for dehydration and carbonization, and then performs sulfonation, comprising the following steps:

(1) Crush the dried plant waste and sieve it with 20-80 mesh;

(2) After sieving, add to concentrated sulfuric acid and mechanically stir, dehydrate and carbonize at room temperature for 10-24 hours, and then sulfonate in an oven at 100-200°C for 15-30 hours to obtain a solid mixture;

(3) Wash the mixture with water until the pH of the filtrate does not change, then filter, dry, pulverize and sieve with 20-80 meshes to obtain a solid acid catalyst.

The plant waste in the step (1) is any one or more of turmeric waste residue, coconut bran, rice bran, wheat husk, peanut shell, bamboo chips, wood chips, and straw.

In the step (2), the plant waste is added to the concentrated sulfuric acid at a mass ratio of plant waste to concentrated sulfuric acid of 1:1-10.

The water washing method in the step (3) is to add water to the mixture according to the mass/volume ratio of the mixture and water in the ratio of 1:3-5, and place it in a water bath at 60-80°C for magnetic stirring, and the stirring time is 30-60 minutes , washed 4 to 6 times with water.

The GDUT-1 solid acid catalyst prepared by the present invention uses cheap and easy-to-obtain plant waste as raw material, and utilizes the dehydration and strong acidity of concentrated sulfuric acid to dehydrate and carbonize the raw material at room temperature to obtain a solid carbon material with a stable structure. Heating sulfonation at 100-200°C, so that the original structural characteristics of biomass can be maintained, and a solid acid catalyst with stable structure, large specific surface area and high acid content can be formed.

Compared with the existing biomass solid acid catalyst preparation technology, the present invention has the following beneficial effects:

(1) The preparation process is simple, and the original structure of the biomass is not damaged. Dehydration and carbonization at room temperature first, and then sulfonation at 100-200 ° C, without high temperature and inert atmosphere, low cost of plant waste, suitable for industrial production;

(2) The prepared GDUT-1 solid acid catalyst has a high acid content of 3.5-5.0 mmol/g. It has high thermal stability, thermal decomposition temperature above 200°C, high catalytic activity, and can be recycled many times. It is an efficient, stable and clean catalyst with wide application prospects.

Detailed ways

The technical solution of the present invention will be described in detail below in conjunction with specific examples. The following examples are for those skilled in the art to better understand the present invention, rather than limiting the technical solution of the present invention.

Example 1

Grind the dried turmeric waste residue and sieve it through 80 meshes; weigh 350g ginger residue powder and add it to 350g concentrated sulfuric acid, stir it mechanically for 18 hours, then place it in an oven at 150°C for 6h and 190°C for 12h to obtain the mixture, press Add water to the mixture at a ratio of 1:3 between the mass of the mixture and the volume of water, place it in a water bath at 70°C for magnetic stirring, stir for 60 minutes, wash with water 4 times, filter and dry after washing, crush and sieve through an 80-mesh sieve to obtain GDUT -1 solid acid catalyst, acidity is 4.28mmol/g.

Example 2

Grind the dried coconut peat and sieve it through a 60-mesh sieve; weigh 150g of coconut peat powder and add it to 450g of concentrated sulfuric acid, stir it mechanically for 12 hours, then place it in an oven, heat it at 140°C for 6h, and at 200°C for 10h to obtain the mixture, press Add water to the mixture at a ratio of 1:5 between the mass of the mixture and the volume of water, place it in a water bath at 60°C for magnetic stirring, stir for 50 minutes, wash with water 5 times, filter and dry after washing, crush and sieve through a 60-mesh sieve to obtain GDUT -1 solid acid catalyst, acidity is 4.84mmol/g.

Example 3

Grind the dried rice bran and sieve it with 20 meshes; weigh 300g of rice bran powder and add it to 1500g of concentrated sulfuric acid, stir it mechanically for 20 hours, then place it in an oven at 130°C for 8h and 180°C for 16h to obtain the mixture. Add water to the mixture at a volume ratio of 1:4, place it in a water bath at 80°C for magnetic stirring, stir for 40 minutes, wash with water 6 times, filter and dry after washing, crush and sieve through a 20-mesh sieve to obtain GDUT-1 Solid acid catalyst, acidity is 4.25mmol/g.

Example 4

Crush the dried wheat husks and sieve them through a 40-mesh sieve; weigh 200g of wheat husk powders and add them to 1900g of concentrated sulfuric acid, stir them mechanically for 24 hours, then place them in an oven at 140°C for 12h and 180°C for 14h to obtain the mixture, press Add water to the mixture at a ratio of 1:4 between the mass of the mixture and the volume of water, place it in a water bath at 70°C for magnetic stirring, stir for 60 minutes, wash with water 4 times, filter and dry after washing, crush and sieve through a 40-mesh sieve to obtain GDUT -1 solid acid catalyst, acidity is 4.90mmol/g.

Example 5

Crush the dried peanut shells and sieve them through a 20-mesh sieve; weigh 750g of peanut shell powder and add them to 1500g of concentrated sulfuric acid, stir them mechanically for 14 hours, then place them in an oven at 120°C for 11h and 200°C for 9h to obtain the mixture, press Add water to the mixture at a ratio of 1:3 between the mass of the mixture and the volume of water, place it in a water bath at 60°C for magnetic stirring, stir for 50 minutes, wash with water 5 times, filter and dry after washing, crush and sieve through a 20-mesh sieve to obtain GDUT -1 solid acid catalyst, acidity is 4.13mmol/g.

Example 6

Grind the dried bamboo chips and sieve them through a 60-mesh sieve; weigh 200g of bamboo powder and add it to 1200g of concentrated sulfuric acid, stir it mechanically for 20 hours, then place it in an oven, keep it at 100°C for 14h, then at 200°C for 10h to get the mixture, press the mixture Add water to the mixture at a mass to water volume ratio of 1:4, place it in a water bath at 80°C for magnetic stirring, stir for 40 minutes, wash with water 6 times, filter and dry after washing, crush and sieve through a 60-mesh sieve to obtain GDUT- 1 solid acid catalyst, the acidity is 3.89mmol/g.

Example 7

Crush the dried sawdust and sieve it through a 40-mesh sieve; weigh 400g of wood powder and add it to 1600g of concentrated sulfuric acid, stir it mechanically for 18 hours, then place it in an oven, keep it at 130°C for 8 hours, and then at 180°C for 16 hours to obtain the mixture. Add water to the mixture at a volume ratio of 1:4, place it in a water bath at 70°C for magnetic stirring, stir for 50 minutes, wash with water 5 times, filter and dry after washing, crush and sieve through a 40-mesh sieve to obtain GDUT-1 Solid acid catalyst, acidity is 4.77mmol/g.

Example 8

Crush the dried straw and sieve it through 20 meshes; weigh 500g of straw powder and add it to 3500g of concentrated sulfuric acid, stir it mechanically for 16 hours, then put it in an oven, keep it at 150°C for 6 hours, and then at 190°C for 13 hours to get the mixture. Add water to the mixture at a volume ratio of 1:5, place it in a water bath at 80°C for magnetic stirring, stir for 40 minutes, wash with water 6 times, filter and dry after washing, crush and sieve through a 20-mesh sieve to obtain GDUT-1 Solid acid catalyst, acidity is 4.19mmol/g.

Example 9

Crush the dried bamboo and wood chips and sieve them through a 60-mesh sieve; weigh 300g of bamboo powder and 300g of wood powder respectively, add them to 3600g of concentrated sulfuric acid in turn, stir them mechanically for 12 hours, then place them in an oven at 130°C for 10 hours , 180°C for 15h to obtain the mixture, add water to the mixture according to the ratio of the mass of the mixture to the volume of water 1:4, place it in a water bath at 70°C for magnetic stirring, stir for 50 minutes, wash with water 5 times, filter and dry after washing, crush and GDUT-1 solid acid catalyst was obtained by sieving with 60 mesh, and the acidity was 4.62mmol/g.

Finally, it should be noted that: the above embodiments are only used to illustrate, rather than limit the technical solution of the present invention, although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the present invention can still be Any modification or partial replacement without departing from the spirit and scope of the present invention shall be covered by the claims of the present invention.

Claims (5)

1. a preparation method for peracid amount solid acid catalyst, described method take plant waste as raw material, first add the concentrated sulfuric acid dehydration carbonization, after carry out sulfonation, it is characterized in that comprising the steps:

(1) plant waste of drying is pulverized also 20 ~ 80 orders to sieve;

(2) to join after sieving in the concentrated sulfuric acid and mechanical agitation, at room temperature dewater carbonization 10 ~ 24h, then sulfonation 15 ~ 30h at 100 ~ 200 DEG C in an oven, obtains solid mixture;

(3) this mixture is washed to pH in solution no longer to change, then filters, dry, pulverize the i.e. obtained solid acid catalyst and 20 ~ 80 orders sieve.

2. the preparation method of peracid amount solid acid catalyst according to claim 1, is characterized in that: in described step (1) plant waste be peltate yam waste slag, coconut palm chaff, rice bran, wheat husk, peanut shell, bamboo bits, wood chip, stalk any one or a few.

3. the preparation method of peracid amount solid acid catalyst according to claim 1, is characterized in that: plant waste joins in the concentrated sulfuric acid by the ratio of mass ratio 1:1 ~ 10 in plant waste and the concentrated sulfuric acid in described step (2).

4. the preparation method of peracid amount solid acid catalyst according to claim 1, it is characterized in that: in described step (3), method for washing is add water in mixture than the ratio of 1:3 ~ 5 in the mass/volume of mixture with water, be placed in the water-bath magnetic agitation of 60 ~ 80 DEG C, mixing time is 30 ~ 60min, washes 4 ~ 6 times.

5. the preparation method of peracid amount solid acid catalyst according to claim 1, is characterized in that: gained solid acid surface acidity is 3.5 ~ 5.0mmol/g, and this solid acid catalyst is called GDUT-1.