WO2021000523A1

WO2021000523A1 - Optimized activation method for polyol hydrogenolysis catalyst

Info

Publication number: WO2021000523A1
Application number: PCT/CN2019/124730
Authority: WO
Inventors: 王爱琴; 刘菲; 雷念; 苗治理; 张涛
Original assignee: 中国科学院大连化学物理研究所
Priority date: 2019-07-02
Filing date: 2019-12-12
Publication date: 2021-01-07
Also published as: CN112169795A; CN112169795B

Abstract

An optimized activation method for a polyol hydrogenolysis catalyst, mainly for solving the technical problem of low conversion rate of the raw material during a reaction process using a reduced catalyst and low selectivity of the target product because it is difficult to activate the active components of the catalyst during the catalyst reduction process for preparing 1,3-propanediol by means of hydrogenolysis of glycerol. The catalyst is composed of a carrier and active components A and B, the carrier being one of aluminum oxide, silicon oxide, zirconium oxide, titanium oxide, or H-ZSM-5 molecular sieve, the active component A being one of tungsten oxide, molybdenum oxide, and rhenium oxide, and the active component B being one of the noble metals, ruthenium, rhodium, palladium, iridium, and platinum. The use of the technical solution in which a mixture of hydrogen and nitrogen is used as the raw material, the raw material is in contact with the catalyst, and the high-valence metal elements in the catalyst are reduced to low-valence active metal elements or simple metal elements, so that the problem above is solved, glycerol can be hydrogenolyzed in high conversion rate and high selectivity under certain hydrogen pressure and temperature so as to produce 1,3-propanediol.

Description

Optimized activation method of polyol hydrogenolysis catalyst

Technical field

The invention relates to an optimized activation method of a polyol hydrogenolysis catalyst. Mainly used for the activation of catalysts for preparing 1,3-propanediol by hydrogenolysis of glycerol.

Background technique

In recent years, glycerol, a by-product of biodiesel, has been produced in large quantities with the rapid development of the biodiesel industry, and the conversion of these crude glycerols into higher value-added chemicals has received greater attention. Glycerin can be directly hydrogenolyzed to produce highly value-added 1,3-propanediol. It can be used directly as a synthetic raw material for antifreeze, plasticizer, detergent, preservative and emulsifier, and can also be used in food, cosmetics and pharmaceuticals. And other industries, its most important use and terephthalic acid reaction generate a promising new polyester PTT. PTT is a new type of biodegradable polyester fiber. It overcomes the shortcomings of too hard polyethylene terephthalate (PET) and too soft polybutylene terephthalate (PBT). At the same time, it has excellent resilience, dyeability, biodegradability, etc., and has huge development potential in industries such as carpets and textile engineering plastics. At present, the industrial production methods of 1,3-propanediol include Shell's ethylene oxide carbonylation hydrogenation method and Degussa's acrolein hydration hydrogenation method.

Ethylene oxide carbonylation hydrogenation method (Chinese patent CN1201407A) means that under the action of a cobalt-based catalyst, ethylene oxide and synthesis gas generate 3-hydroxypropionaldehyde, and then the 3-hydroxyl Propionaldehyde is hydrogenated with hydrogen to produce 1,3-propanediol. Acrolein hydration and hydrogenation method (Chinese patent CN93114516.3) refers to the dehydration of gaseous glycerin hydrate under solid acid catalyst to produce acrolein, which is then hydrated under the action of acid catalyst to produce 3-hydroxypropionaldehyde, which produces 3-hydroxypropanal. Aldehydes are hydrogenated under conventional hydrogenation catalysts to form 1,3-propanediol.

The ethylene oxide carbonylation hydrogenation method has a large investment in equipment, a high technical difficulty, a harsh and unstable preparation process, and the cobalt-based catalyst used is highly toxic. The process of hydration and hydrogenation of acrolein is complicated and the cost is relatively high. Moreover, acrolein itself is a highly toxic, flammable and explosive material, which is difficult to store and transport.

The literature (Appl.Microbiol.Biotechnol.1992,36,592-597) reported a method for preparing 1,3-propanediol by using Clostriiurn strain biotransformation, which can convert 110g/L glycerol solution to 56g/L after 29h 1,3-Propanediol, this method is affected by the biological metabolism activity, the production efficiency is low, and because of the low product concentration, the energy consumption required to purify and separate 1,3-propanediol is also high.

The literature (Journal of Catalysis.2015, 323, 65-75) reported a 9Pt/8WO3/Al2O3 catalyst for the direct hydrogenolysis of glycerol to prepare 1,3-propanediol. The author used a reactor to reduce 0.35g of catalyst in situ , The reduction pressure is 0.1MPa H2, the reduction temperature is 450°C, the reduction time is 1h, and the hydrogen flow rate is 100ml/min. Using 42ml of 5% glycerin aqueous solution as raw material, initial hydrogen pressure of 4.5MPa, reaction temperature of 220°C, after 24 hours of reaction, the yield of 1,3-propanediol was only 18.8%, and the reaction efficiency was very low.

The literature (ACS Catal.2015, 5,5679-5695) reported an 8Pt-7.6Re/SiO2 catalyst. The author used a reactor to reduce the catalyst in situ. The reduction pressure was 1.4MPa H2, and the reduction temperature was 120°C. The time is 1h. The catalyst converts 1% glycerol under the reaction conditions of 120°C and 4MPa H2 pressure, and the 1,3-propanediol yield is only 2.2% after 4 hours of reaction.

The conversion efficiency of glycerol to 1,3-propanediol in the above reaction is very low, which may be related to the activation mode of the catalyst.

The direct hydrogenolysis of glycerol to produce 1,3-propanediol has received great attention in recent years because of its simple process and cheap raw materials. The activation method of the catalyst has an important influence on this reaction. Therefore, it is necessary to investigate and optimize the activation method of the catalyst to improve the conversion rate of glycerol and the yield of 1,3-propanediol to realize industrial application.

Summary of the invention

The invention relates to an optimized activation method of a polyol hydrogenolysis catalyst. It is mainly used for the activation of a catalyst for preparing 1,3-propanediol by hydrogenolysis of glycerol. Compared with the prior art, the technology of the invention effectively improves the conversion rate of glycerol and the yield of 1,3-propanediol.

The patent of the present invention provides an optimized method for activating a polyol hydrogenolysis catalyst. The catalyst is composed of a carrier and active components A and B. The carrier is one of alumina, silica, zirconia, titania or molecular sieve. Component A is one of tungsten oxide, molybdenum oxide, and rhenium oxide, and active component B is one of noble metals ruthenium, rhodium, palladium, iridium, and platinum. The catalyst activation method is as follows: using a mixed gas containing hydrogen and nitrogen as the raw material, the volumetric space velocity is 100～10000/h, the reduction reaction pressure is 0～10.0MPa, the reduction temperature is 100～600℃, and the reduction temperature is increased by programmed heating. And control the heating rate to be less than 20°C/min.

The catalyst of the present invention is prepared by a continuous impregnation method, and the specific process is:

The precursor solution (ammonium metatungstate, ammonium molybdate or ammonium perrhenate) of active component A (one of tungsten oxide, molybdenum oxide, rhenium oxide) is impregnated in the carrier (alumina, silicon oxide) by a wet method , Zirconium oxide, titanium oxide or molecular sieve), the immersion time is 1-18h, drying in an oven at 120℃ for more than 10h, and calcining in a muffle furnace at 300-900℃ for 1-10h, the composite oxide obtained is recorded As A/carrier, the precursor solution (ruthenium chloride, rhodium chloride, palladium chloride, chloroiridic acid or chloroplatinum) of active component B (one of the noble metals ruthenium, rhodium, palladium, iridium, and platinum) Acid) is impregnated on A/support by wet method, the immersion time is 1-18h, drying in 120℃ oven for more than 10h, and muffle furnace at 300-900℃ for 1-10h. The obtained catalyst is denoted as B/A/ Carrier.

The catalyst of the present invention adopts continuous fixed-bed reactor for in-situ reduction, and the specific process is as follows:

Using a mixture of hydrogen and nitrogen as raw materials (hydrogen content greater than or equal to 10%, less than or equal to 100%), the volumetric space velocity is 500-5000/h, the reduction reaction pressure is 0-6.0MPa, and the reduction temperature is 100- At 600℃, the reduction heating adopts programmed heating and the control heating rate is less than 20℃/min.

The catalyst is used in the hydrogenolysis of glycerin aqueous solution to prepare 1,3-propanediol. The reaction conditions are as follows: the reaction is carried out in a continuous fixed-bed reactor, the reaction raw material is glycerin aqueous solution, and the raw material mass concentration is 1-100%, hydrogen The pressure is 0.1-10MPa, the reaction temperature is 80-300°C, the reaction time is 0.2-80h, and the amount of catalyst is 0.01-5g. After cooling, the liquid product was analyzed by an Agilent 7890B gas chromatograph equipped with an INNO WAX capillary column, and the gas phase product was analyzed by an Agilent 7890B gas chromatograph equipped with a HayeSep packed column.

Compared with the prior art, the invention can significantly improve the conversion rate of glycerol and the yield of 1,3-propanediol.

Detailed ways

The present invention will be further illustrated below through specific examples and comparative examples.

Example 1

The catalyst used is Pt/WOx/Al ₂ O ₃ (2.2≤x≤2.7), and its composition is Pt%=2wt%, W%=10wt%, and the rest is Al ₂ O ₃ support. The catalyst is prepared by continuous equal volume impregnation. The specific preparation steps include: the precursor solution of active component tungsten oxide (ammonium metatungstate) is loaded on the carrier alumina by the equal volume impregnation method, and the impregnation time is 15h, 120℃ oven Dry for 15h in the medium and calcine at 500℃ for 5h in a muffle furnace. The composite oxide obtained is recorded as WO ₃ /Al ₂ O ₃ ; the precursor solution of active component platinum (chloroplatinic acid) is loaded on WO ₃ / Al on ₂ O _3, the immersion time is 15h, dried in an oven at 120 deg.] C 15h, 5h calcined in a muffle furnace at 500 ℃, referred to the catalyst obtained was _{_{Pt / WO 3 / Al 2 O}} 3. A continuous fixed bed reactor is used to reduce and activate the Pt/WO ₃ /Al ₂ O ₃ catalyst. The specific process is: 1g of catalyst is filled with a mixture of hydrogen and nitrogen as raw materials (hydrogen volume content 50%), and the volume is empty. The speed is 2000/h, the reduction reaction pressure is 3MPa, the reduction temperature is 400°C, the reduction temperature rise is programmed and the temperature rise rate is controlled to 2°C/min, and the reduced sample is recorded as Pt/WOx/Al ₂ O ₃ . After the reduction, the glycerol is directly converted on a fixed bed reactor, the mass concentration of the glycerol aqueous solution is 50%, the reaction temperature is 200°C, the reaction pressure is 7MPa, the gas space velocity is 1000/h, and the liquid space velocity is 2/h.

Example 2

The hydrogen volume concentration in the mixed gas of hydrogen and nitrogen was changed to 20%, and the other conditions were the same as in Example 1.

Example 3

The hydrogen volume concentration in the mixed gas of hydrogen and nitrogen was changed to 80%, and other conditions were the same as in Example 1.

Example 4

The volumetric space velocity of the mixed gas of hydrogen and nitrogen (hydrogen volume content 50%) is changed to 500/h, and the other conditions are the same as in Example 1.

Example 5

Change the volumetric space velocity of the mixture of hydrogen and nitrogen (hydrogen volume content 50%) to 4000/h, and other conditions are the same as in Example 1.

Example 6

The reduction pressure was changed to 0.1 MPa, and the other conditions were the same as in Example 1.

Example 7

The reduction pressure was changed to 1 MPa, and the other conditions were the same as in Example 1.

Example 8

The reduction pressure was changed to 5 MPa, and the other conditions were the same as in Example 1.

Example 9

The reduction temperature was changed to 100°C, and the other conditions were the same as in Example 1.

Example 10

The reduction temperature was changed to 200°C, and the other conditions were the same as in Example 1.

Example 11

The reduction temperature was changed to 300°C, and the other conditions were the same as in Example 1.

Example 12

The reduction temperature was changed to 500°C, and the other conditions were the same as in Example 1.

Example 13

The reduction temperature was changed to 600°C, and the other conditions were the same as in Example 1.

Example 14

The heating rate during the reduction was changed to 0.5° C./min, and other conditions were the same as in Example 1.

Example 15

The heating rate during the reduction was changed to 5°C/min, and other conditions were the same as in Example 1.

Example 16

The heating rate during the reduction was changed to 10° C./min, and the other conditions were the same as in Example 1.

Example 17

The catalyst used is Ir/ReO _z /Al ₂ O ₃ (0.5≤z≤2.0), and its composition is Ir%=2wt%, Re%=10wt%, and the rest is Al ₂ O ₃ carrier. The catalyst is prepared by continuous equal volume impregnation. The specific preparation steps include: the precursor solution of the active component rhenium oxide (ammonium perrhenate) is loaded on the carrier alumina by the equal volume impregnation method, and the impregnation time is 15h, 120℃ oven Dry for 15h in the middle and calcine at 500℃ for 5h in a muffle furnace. The composite oxide obtained is recorded as Re ₂ O ₇ /Al ₂ O ₃ ; the precursor solution of the active component iridium (chloroiridic acid) is passed through the equal volume impregnation method Loaded on Re ₂ O ₇ /Al ₂ O ₃ , the immersion time is 15h, the drying time is 15h in 120℃ oven, and the catalyst is calcined at 500℃ for 5h in muffle furnace. The obtained catalyst is denoted as Ir/Re ₂ O ₇ /Al ₂ O ₃ . A continuous fixed bed reactor is used to reduce and activate the Ir/Re ₂ O ₇ /Al ₂ O ₃ catalyst. The specific process is: 1g of catalyst is filled with a mixture of hydrogen and nitrogen as raw materials (hydrogen volume content 20%). The volumetric space velocity is 2000/h, the reduction reaction pressure is 3MPa, the reduction temperature is 300°C, the reduction temperature rise is programmed and the temperature rise rate is controlled to 5°C/min, and the reduced sample is recorded as Ir/ReO _z /Al ₂ O ₃ . After the reduction, the glycerol is directly converted on a fixed bed reactor, the mass concentration of the glycerol aqueous solution is 50%, the reaction temperature is 200°C, the reaction pressure is 7MPa, the gas space velocity is 1000/h, and the liquid space velocity is 2/h.

Example 18

The hydrogen volume concentration in the mixed gas of hydrogen and nitrogen was changed to 50%, and the other conditions were the same as in Example 17.

Example 19

The hydrogen volume concentration in the mixed gas of hydrogen and nitrogen was changed to 80%, and the other conditions were the same as in Example 17.

Example 20

The volumetric space velocity of the mixed gas of hydrogen and nitrogen (hydrogen volume content 20%) was changed to 500/h, and the other conditions were the same as in Example 17.

Example 21

The volumetric space velocity of the mixed gas of hydrogen and nitrogen (hydrogen volume content 20%) was changed to 4000/h, and the other conditions were the same as in Example 17.

Example 22

The reduction pressure was changed to 0.1 MPa, and the other conditions were the same as in Example 17.

Example 23

The reduction pressure was changed to 1 MPa, and the other conditions were the same as in Example 17.

Example 24

The reduction pressure was changed to 5 MPa, and the other conditions were the same as in Example 17.

Example 25

The reduction temperature was changed to 100°C, and the other conditions were the same as in Example 17.

Example 26

The reduction temperature was changed to 200°C, and the other conditions were the same as in Example 17.

Example 27

The reduction temperature was changed to 400°C, and the other conditions were the same as in Example 17.

Example 28

The reduction temperature was changed to 500°C, and the other conditions were the same as in Example 17.

Example 29

The reduction temperature was changed to 600°C, and the other conditions were the same as in Example 17.

Example 30

The heating rate during the reduction was changed to 0.5° C./min, and the other conditions were the same as in Example 17.

Example 31

The heating rate during the reduction was changed to 2°C/min, and the other conditions were the same as in Example 17.

Example 32

The heating rate during the reduction was changed to 10°C/min, and other conditions were the same as in Example 17.

Example 33

The catalyst used is Ru/MoO _y /Al ₂ O ₃ (2.0≤y≤2.5), and its composition is Ru%=2wt%, Mo%=10wt%, and the rest is Al ₂ O ₃ support. The catalyst is prepared by continuous equal volume impregnation. The specific preparation steps include: the precursor solution of the active component rhenium oxide (ammonium molybdate) is loaded on the carrier alumina by the equal volume impregnation method, and the impregnation time is 15h in an oven at 120°C. After drying for 15 hours and calcining in a muffle furnace at 500°C for 5 hours, the composite oxide obtained is denoted as MoO ₃ /Al ₂ O ₃ ; the precursor solution of the active component iridium (ruthenium chloride) is loaded on MoO by an isometric impregnation method _{On 3} /Al ₂ O ₃ , the immersion time was 15 hours, dried in an oven at 120°C for 15 hours, and calcined in a muffle furnace at 500°C for 5 hours. The resulting catalyst was denoted as Ru/MoO ₃ /Al ₂ O ₃ . A continuous fixed bed reactor is used to reduce and activate the Ru/MoO ₃ /Al ₂ O ₃ catalyst. The specific process is as follows: 1g catalyst is filled with a mixture of hydrogen and nitrogen as raw materials (hydrogen volume content 20%), and the volume is empty. The speed is 2000/h, the reduction reaction pressure is 1MPa, the reduction temperature is 200°C, the reduction temperature rise is programmed to increase the temperature and the temperature rise rate is controlled to 5°C/min, and the reduced sample is recorded as Ru/MoO _y /Al ₂ O ₃ . After the reduction, the glycerol is directly converted on a fixed bed reactor, the mass concentration of the glycerol aqueous solution is 50%, the reaction temperature is 200°C, the reaction pressure is 7MPa, the gas space velocity is 1000/h, and the liquid space velocity is 2/h.

Example 34

The hydrogen volume concentration in the mixed gas of hydrogen and nitrogen was changed to 50%, and the other conditions were the same as in Example 33.

Example 35

The hydrogen volume concentration in the mixed gas of hydrogen and nitrogen was changed to 80%, and the other conditions were the same as in Example 33.

Example 36

The volumetric space velocity of the mixed gas of hydrogen and nitrogen (hydrogen volume content 20%) was changed to 500/h, and the other conditions were the same as in Example 33.

Example 37

The volumetric space velocity of the mixed gas of hydrogen and nitrogen (hydrogen volume content 20%) was changed to 4000/h, and the other conditions were the same as in Example 33.

Example 38

The reduction pressure was changed to 0.1 MPa, and the other conditions were the same as in Example 33.

Example 39

The reduction pressure was changed to 3 MPa, and the other conditions were the same as in Example 33.

Example 40

The reduction pressure was changed to 5 MPa, and the other conditions were the same as in Example 33.

Example 41

The reduction temperature was changed to 100°C, and the other conditions were the same as in Example 33.

Example 42

The reduction temperature was changed to 300°C, and the other conditions were the same as in Example 33.

Example 43

The reduction temperature was changed to 400°C, and the other conditions were the same as in Example 33.

Example 44

The reduction temperature was changed to 500°C, and other conditions were the same as in Example 33.

Example 45

The reduction temperature was changed to 600°C, and the other conditions were the same as in Example 33.

Example 46

The temperature increase rate during reduction was changed to 0.5° C./min, and the other conditions were the same as in Example 33.

Example 47

The heating rate during the reduction was changed to 2° C./min, and the other conditions were the same as in Example 33.

Example 48

The temperature increase rate during the reduction was changed to 10°C/min, and the other conditions were the same as in Example 33.

Comparative example 1

The catalyst has not been reductively activated, and other conditions are the same as in Example 1.

Comparative example 2

The catalyst was not reductively activated, and the other conditions were the same as in Example 17.

Comparative example 3

The catalyst was not reductively activated, and the other conditions were the same as in Example 33.

Comparative example 4

The catalyst used is Pt/Al ₂ O ₃ with a composition of Pt%=2wt%, and the rest is Al ₂ O ₃ support. The catalyst is prepared by an equal volume impregnation method, and the specific preparation steps include: the precursor solution of active component platinum (chloroplatinic acid) is loaded on Al ₂ O ₃ by an equal volume impregnation method, and the immersion time is 15 hours and dried in an oven at 120°C. 15h, calcined in a muffle furnace at 500°C for 5h, and the obtained catalyst is recorded as Pt/Al ₂ O ₃ . A continuous fixed bed reactor is used to reduce and activate the Pt/Al ₂ O ₃ catalyst. The specific process is: 1g of catalyst is filled with a mixture of hydrogen and nitrogen as raw materials (hydrogen volume content 50%), and the volumetric space velocity is 2000 /h, the reduction reaction pressure is 3MPa, the reduction temperature is 400°C, and the reduction temperature rise is programmed to increase and the temperature rise rate is controlled to 2°C/min. After the reduction, the glycerol is directly converted on a fixed bed reactor, the mass concentration of the glycerol aqueous solution is 50%, the reaction temperature is 200°C, the reaction pressure is 7MPa, the gas space velocity is 1000/h, and the liquid space velocity is 2/h.

Comparative example 5

The catalyst used is WO _x /Al ₂ O ₃ (2.2≤x≤2.7), its composition is W%=10wt%, and the rest is Al ₂ O ₃ support. The catalyst is prepared by an equal volume impregnation method, and the specific preparation steps include: the precursor solution of the active component tungsten oxide (ammonium metatungstate) is loaded on the carrier alumina by an equal volume impregnation method, and the impregnation time is 15h in an oven at 120°C After drying for 15 hours and calcining in a muffle furnace at 500°C for 5 hours, the obtained composite oxide is recorded as WO ₃ /Al ₂ O ₃ . A continuous fixed bed reactor is used to reduce and activate the WO ₃ /Al ₂ O ₃ catalyst. The specific process is as follows: 1g catalyst is filled with a mixture of hydrogen and nitrogen as raw materials (hydrogen volume content 50%), and the volumetric space velocity is 2000/h, the reduction reaction pressure is 3MPa, the reduction temperature is 400°C, the reduction temperature rise is programmed to increase and the temperature rise rate is controlled to 2°C/min, and the reduced sample is recorded as WO _x /Al ₂ O ₃ . After the reduction, the glycerol is directly converted on a fixed bed reactor, the mass concentration of the glycerol aqueous solution is 50%, the reaction temperature is 200°C, the reaction pressure is 7MPa, the gas space velocity is 1000/h, and the liquid space velocity is 2/h.

Comparative example 6

The catalyst used is Ir/Al ₂ O ₃ , the composition of which is Ir%=2wt%, and the rest is Al ₂ O ₃ support. The catalyst is prepared by an equal volume impregnation method, and the specific preparation steps include: the precursor solution of the active component iridium (chloroiridic acid) is loaded on Al ₂ O ₃ by an equal volume impregnation method, and the immersion time is 15 hours and dried in an oven at 120°C for 15 hours , Calcined in a muffle furnace at 500 ℃ for 5 hours, the obtained catalyst is recorded as Ir/Al ₂ O ₃ . A continuous fixed bed reactor is used to reduce and activate the Ir/Al ₂ O ₃ catalyst. The specific process is as follows: 1g catalyst is filled with a mixture of hydrogen and nitrogen as raw materials (hydrogen volume content 20%), and the volumetric space velocity is 2000 /h, the reduction reaction pressure is 3MPa, the reduction temperature is 300°C, the reduction temperature rise adopts a programmed temperature rise and the control temperature rise rate is 5°C/min. After the reduction, the glycerol is directly converted on a fixed bed reactor, the mass concentration of the glycerol aqueous solution is 50%, the reaction temperature is 200°C, the reaction pressure is 7MPa, the gas space velocity is 1000/h, and the liquid space velocity is 2/h.

Comparative example 7

The catalyst used is ReO _z /Al ₂ O ₃ (0.5≤z≤2.0), and its composition is Re%=10wt%, and the rest is Al ₂ O ₃ support. The catalyst is prepared by continuous equal volume impregnation. The specific preparation steps include: the precursor solution of the active component rhenium oxide (ammonium perrhenate) is loaded on the carrier alumina by the equal volume impregnation method, and the impregnation time is 15h, 120℃ oven Dry for 15 hours in a medium and calcine at 500°C for 5 hours in a muffle furnace. The obtained composite oxide is recorded as Re ₂ O ₇ /Al ₂ O ₃ . A continuous fixed bed reactor is used to reduce and activate the Re ₂ O ₇ /Al ₂ O ₃ catalyst. The specific process is as follows: 1g of catalyst is filled with a mixture of hydrogen and nitrogen as raw materials (hydrogen volume content 20%), and the volume is empty. The speed is 2000/h, the reduction reaction pressure is 3MPa, the reduction temperature is 300°C, the reduction temperature rise is programmed and the temperature rise rate is controlled to 5°C/min, and the reduced sample is recorded as ReO _z /Al ₂ O ₃ . After the reduction, the glycerol is directly converted on a fixed bed reactor, the mass concentration of the glycerol aqueous solution is 50%, the reaction temperature is 200°C, the reaction pressure is 7MPa, the gas space velocity is 1000/h, and the liquid space velocity is 2/h.

Comparative example 8

The catalyst used is Ru/Al ₂ O ₃ , the composition of which is Ru%=2wt%, and the rest is Al ₂ O ₃ support. The catalyst is prepared by an equal volume impregnation method, and the specific preparation steps include: the precursor solution of the active component iridium (ruthenium chloride) is loaded on Al ₂ O ₃ by an equal volume impregnation method, and the immersion time is 15 hours and dried in an oven at 120° 15h, calcined in a muffle furnace at 500°C for 5h, and the resulting catalyst is denoted as Ru/Al ₂ O ₃ . The Ru/Al ₂ O ₃ catalyst is reduced and activated by a continuous fixed bed reactor. The specific process is: 1g catalyst is filled with a mixture of hydrogen and nitrogen as raw materials (hydrogen volume content 20%), and the volumetric space velocity is 2000 /h, the reduction reaction pressure is 1MPa, the reduction temperature is 200°C, the reduction temperature rise is programmed to increase and the temperature rise rate is controlled to 5°C/min. After the reduction, the glycerol is directly converted on a fixed bed reactor, the mass concentration of the glycerol aqueous solution is 50%, the reaction temperature is 200°C, the reaction pressure is 7MPa, the gas space velocity is 1000/h, and the liquid space velocity is 2/h.

Comparative example 9

The catalyst used is MoO _y /Al ₂ O ₃ (2.0≤y≤2.5), and its composition is Mo%=10wt%, and the rest is Al ₂ O ₃ support. The catalyst is prepared by continuous equal volume impregnation. The specific preparation steps include: the precursor solution of the active component rhenium oxide (ammonium molybdate) is loaded on the carrier alumina by the equal volume impregnation method, and the impregnation time is 15h in an oven at 120°C. After drying for 15 hours and calcining in a muffle furnace at 500°C for 5 hours, the composite oxide obtained is denoted as MoO ₃ /Al ₂ O ₃ . A continuous fixed bed reactor is used to reduce and activate the MoO ₃ /Al ₂ O ₃ catalyst. The specific process is: 1g of catalyst is filled with a mixture of hydrogen and nitrogen as raw materials (hydrogen volume content 20%), and the volumetric space velocity is 2000/h, the reduction reaction pressure is 1MPa, the reduction temperature is 200°C, the reduction temperature rise is programmed to increase and the temperature rise rate is controlled to 5°C/min, the sample after reduction is recorded as MoO _y /Al ₂ O ₃ . After the reduction, the glycerol is directly converted on a fixed bed reactor, the mass concentration of the glycerol aqueous solution is 50%, the reaction temperature is 200°C, the reaction pressure is 7MPa, the gas space velocity is 1000/h, and the liquid space velocity is 2/h.

It can be seen from Comparative Examples 1, 2 and 3 that the reduction activation treatment plays a vital role in the catalytic performance of the catalyst, and the catalyst without reduction activation has almost no activity.

It can be seen from Example 1 and Comparative Examples 4 and 5 that after alumina is loaded with active component Pt or tungsten oxide alone, its activity in catalyzing the hydrogenolysis of glycerol to produce 1,3-propanediol is extremely low. Only after tungsten has higher reactivity.

It can be seen from Example 17 and Comparative Examples 6,7 that after alumina alone supports the active component Ir or rhenium oxide, its activity in catalyzing the hydrogenolysis of glycerol to produce 1,3-propanediol is extremely low, only supporting both Ir and oxidation After rhenium has higher reactivity.

From Example 33 and Comparative Examples 8,9, it can be seen that after alumina alone supports the active component Ru or molybdenum oxide, the activity of catalyzing the hydrogenolysis of glycerol to produce 1,3-propanediol is extremely low. After molybdenum, it has higher reactivity.

Examples 1-3 investigated the influence of the hydrogen content in the reducing gas on the activity of the Pt/WO _x /Al ₂ O ₃ catalyst. From the results, we can see that the catalytic activity is optimal when the hydrogen content in the reducing gas is 50% : The conversion rate of glycerol and the yield of 1,3-propanediol are both the highest.

Examples 1, 4, and 5 investigated the influence of the volumetric space velocity of the reducing gas on the activity of the Pt/WO _x /Al ₂ O ₃ catalyst. From the results, we can see that the volumetric space velocity of the reducing gas is optimal when 2000/h .

Examples 1, 6, 7, and 8 investigated the effect of reduction pressure on the activity of Pt/WO _x /Al ₂ O ₃ catalyst. From the results, we can see that as the reduction pressure increases from 0.1 MPa to 3 MPa, the glycerol conversion rate and 1 The yield of 3-propanediol is constantly increasing, and when it continues to increase to 5MPa, the conversion rate of glycerol and the yield of 1,3-propanediol decrease instead. It can be concluded that the catalytic activity is optimal when the reduction pressure is 3MPa.

Examples 1,9,10,11,12,13 The effect of reduction temperature on the activity of Pt/WO _x /Al ₂ O ₃ catalysts. From the results, we can see that as the reduction temperature increases from 100°C to 400°C, glycerol The conversion rate and the yield of 1,3-propanediol are constantly increasing, and when the temperature continues to increase to 500,600°C, the conversion rate of glycerol and the yield of 1,3-propanediol show a downward trend. It is concluded that the optimal reduction temperature is 400°C.

Examples 1, 14, 15, 16 investigated the effect of the heating rate during reduction on the activity of the Pt/WO _x /Al ₂ O ₃ catalyst. From the results, we can see that the heating rate during reduction is 2℃/min. The catalytic activity is the best, and the glycerol conversion rate and 1,3-propanediol yield are both the highest.

Table 1 Performance comparison of glycerol conversion to 1,3-propanediol under different reducing conditions

Examples 17-19 investigated the influence of the hydrogen content in the reducing gas on the activity of the Ir/ReO _z /Al ₂ O ₃ catalyst. From the results, we can see that as the hydrogen content in the reducing gas increases: the conversion rate of glycerol and 1, The yield of 3-propanediol is constantly decreasing, and the optimal hydrogen content is 20%.

Examples 17, 20, and 21 investigated the influence of the volumetric space velocity of the reducing gas on the activity of the Ir/ReO _z /Al ₂ O ₃ catalyst. From the results, we can see that the volumetric space velocity of the reducing gas is optimal when 2000/h At this time, the conversion rate of glycerol and the yield of 1,3-propanediol are both the highest.

Examples 17, 22, 23, and 24 investigated the effect of reduction pressure on the activity of Ir/ReO _z /Al ₂ O ₃ catalysts. From the results, we can see that as the reduction pressure increases from 0.1 MPa to 3 MPa, the glycerol conversion rate and 1 The yield of 3-propanediol is constantly increasing, and when it continues to increase to 5MPa, the conversion rate of glycerol and the yield of 1,3-propanediol decrease instead. It can be concluded that the catalytic activity is optimal when the reduction pressure is 3MPa.

In Examples 17, 25, 26, 27, 28, 29, the effect of reduction temperature on the activity of Ir/ReO _z /Al ₂ O ₃ catalysts. From the results, we can see that as the reduction temperature increases from 100°C to 300°C, glycerol The conversion rate and the yield of 1,3-propanediol are constantly increasing, and when the temperature continues to increase to 400, 500, and 600°C, the conversion rate of glycerol and the yield of 1,3-propanediol show a downward trend. It can be concluded that the optimal reduction temperature is 300°C.

Examples 17, 30, 31, and 32 investigated the influence of the heating rate during reduction on the activity of the Ir/ReO _z /Al ₂ O ₃ catalyst. From the results, we can see that the better heating rate is 5°C/min. The conversion rate of glycerol and the yield of 1,3-propanediol are both the highest.

Examples 33-35 investigated the influence of the hydrogen content in the reducing gas on the activity of the Ru/MoO _y /Al ₂ O ₃ catalyst. From the results, we can see that as the hydrogen content in the reducing gas increases: the conversion rate of glycerol and 1, The yield of 3-propanediol is constantly decreasing, and the optimal hydrogen content is 20%.

Examples 33, 36, and 37 investigated the influence of the volumetric space velocity of the reducing gas on the activity of the Ru/MoO _y /Al ₂ O ₃ catalyst. From the results, we can see that the volumetric space velocity of the reducing gas is optimal when 2000/h At this time, the conversion rate of glycerol and the yield of 1,3-propanediol are both the highest.

Examples 33, 38, 39, and 40 investigated the effect of reduction pressure on the activity of Ru/MoO _y /Al ₂ O ₃ catalysts. From the results, we can see that as the reduction pressure increases from 0.1 MPa to 1 MPa, the glycerol conversion rate and 1 The yield of 3-propanediol is constantly increasing, and when it continues to increase to 3 or 5 MPa, the conversion rate of glycerol and the yield of 1,3-propanediol decrease instead. It can be concluded that the catalytic activity is optimal when the reduction pressure is 1 MPa.

Examples 33, 41, 42, 43, 44, 45, the effect of reduction temperature on the activity of Ru/MoO _y /Al ₂ O ₃ catalyst, we can see from the results that as the reduction temperature increases from 100°C to 200°C, glycerol The conversion rate and the yield of 1,3-propanediol are constantly increasing, and when the temperature continues to increase to 300, 400, 500, and 600°C, the conversion rate of glycerol and the yield of 1,3-propanediol show a downward trend. Therefore, the optimal reduction temperature is 200°C.

Examples 33, 46, 47, and 48 investigated the effect of the heating rate during reduction on the activity of the Ru/MoO _y /Al ₂ O ₃ catalyst. From the results, we can see that the better heating rate is 5°C/min. The conversion rate of glycerol and the yield of 1,3-propanediol are both the highest.

It can be seen from the above results that the reduction method of the catalyst of the present invention can greatly increase the conversion rate of glycerol and the yield of the target product 1,3-propanediol after the catalyst used in the present invention is reductively activated, showing that the method of the present invention It has a significant effect on the reaction of glycerol hydrogenolysis to produce 1,3-propanediol.

Claims

The optimized activation method of polyol hydrogenolysis catalyst is characterized in that by using a mixed gas containing hydrogen and nitrogen (hydrogen volume concentration is preferably 5 to 90%, more preferably 10 to 60%) as raw materials, the volumetric space velocity is 100～10000/h (preferably 100～8000/h, more preferably 500～3000/h), reduction reaction pressure is 0.1～10.0MPa (preferably 0.1～5.0MPa, more preferably 0.5～3.5MPa), reduction temperature is 100～ 600°C (preferably 100-500°C, more preferably 150-450°C), the reduction temperature rise adopts a programmed temperature increase and the temperature rise rate is controlled to be less than 20°C/min (preferably 0.1-15°C/min, more preferably 1-6°C/min) Under conditions, the raw materials contact with the catalyst, the high-valence metal elements in the catalyst are reduced to low-valence active metal elements or simple metal elements, and the active component A (tungsten oxide, molybdenum oxide, rhenium oxide) is oxidized by the high-valence metal Substances (WO 3 , MoO 3 , Re 2 O 7 ) are reduced to low-valent metal oxides (WO x ,2.2≤x≤2.7, MoO y ,2.0≤y≤2.5, ReO z ,0.5≤z≤2.0 ), the oxides (ruthenium dioxide, rhodium trioxide, palladium monoxide, iridium dioxide, platinum dioxide) of the active component B (noble metals ruthenium, rhodium, palladium, iridium, platinum) are reduced to metal element;

The catalyst is composed of a carrier and active components A and B. The carrier is one or more of aluminum oxide, silicon oxide, zirconium oxide, titanium oxide or molecular sieve, and the active component A is tungsten oxide, molybdenum oxide, and One or more of rhenium, and the active component B is one or more of precious metals ruthenium, rhodium, palladium, iridium, and platinum.
The activation method of claim 1, wherein the catalyst is prepared by a continuous impregnation method, and the specific process is:

The precursor solution of active component A (one or more of tungsten oxide, molybdenum oxide and rhenium oxide) (one or more of ammonium metatungstate, ammonium molybdate or ammonium perrhenate) It is impregnated on the carrier (one or more of alumina, silica, zirconia, titanium oxide or molecular sieve) by wet method, and the immersion time is 1-18h (preferably 1-15h, more preferably 6-15h), Drying in an oven at 100-120℃ for more than 10h (preferably 10-30h, more preferably 12-16h), calcination in a muffle furnace at 300-900℃ (preferably 300-800℃, more preferably 350-550℃) for 1-10h ( Preferably 1-8h, more preferably 3-6h), the obtained composite oxide is referred to as A/support, and the active component B (one or more of the noble metal ruthenium, rhodium, palladium, iridium, and platinum) The precursor solution (one or more of ruthenium chloride, rhodium chloride, palladium chloride, chloroiridic acid or chloroplatinic acid) is impregnated on the A/support by a wet method, and the immersion time is 1-18h (preferably 1-15h, more preferably 6-15h), 100-120℃ drying oven for more than 10h (preferably 10-30h, more preferably 12-16h), muffle furnace 300-900℃ (preferably 300-800℃, more preferably It is calcined at 350-550°C for 1-10h (preferably 1-8h, more preferably 3-6h), and the obtained catalyst is denoted as B/A/support.
The activation method according to claim 1, characterized in that: a mixed gas containing hydrogen and nitrogen (hydrogen volume concentration is preferably 5 to 90%, more preferably 10 to 60%) is used as a raw material, and the volumetric space velocity is 100 to 10,000. /h (preferably 100-8000/h, more preferably 500-3000/h), reduction reaction pressure is 0.1-10.0 MPa (preferably 0.1-5.0 MPa, more preferably 0.5-3.5 MPa), reduction temperature is 100-600°C ( It is preferably 100-500°C, more preferably 150-450°C), the reduction temperature rise adopts a temperature program and the temperature rise rate is controlled to be less than 20°C/min (preferably 0.1-15°C/min, more preferably 1-6°C/min).
The activation method according to claim 1, 2 or 3, characterized in that: the catalyst is used in the reaction of glycerol hydrogenolysis to prepare 1,3-propanediol, the reaction raw material is glycerin aqueous solution, wherein the mass concentration of glycerin is 1-100% (Preferably 20-90%, more preferably 30-80%), hydrogen pressure is 0.1-10MPa (preferably 1-9MPa, more preferably 3-8MPa), reaction temperature is 80-300°C (preferably 120-250°C, more preferably 150-210℃), gas space velocity is 200-4000/h (preferably 500-3000/h, more preferably 500-2000/h), liquid space velocity is 0.2-5/h (preferably 0.5-4/h, more Preferably 1-3/h), the amount of catalyst is 0.01-5g (preferably 0.2-4g, more preferably 0.5-2g).
The activation method according to claim 4, wherein the catalyst is also suitable for the hydrogenolysis of other polyols to prepare lower alcohols, such as 1,2-propanediol to prepare n-propanol, ethylene glycol to prepare ethanol, 1,2-Butanediol to produce n-butanol, 1,2,4-butanetriol to produce 1,4-butanediol, 1,2,5-pentanetriol to produce 1,5-pentanediol , 1,2,6-hexanetriol to produce 1,6-hexanediol.
According to the method of claim 4, the selectivity of obtaining 1,3-propanediol is 10-60%, and the conversion rate of glycerol is 10-90%.
According to the method of claim 4, the reaction for preparing 1,3-propanediol by hydrogenolysis of glycerol is applicable to both fixed bed and reactor.