CN104961625A - Method for synthesizing 1,2-propylene glycol using glucose - Google Patents

Abstract

The invention discloses a method for synthesizing 1,2-propylene glycol using glucose, and belongs to the fields of environment protection and energy technology. The method is the technology which is characterized in that glucose of high density is used as a raw material, CuNi/MgO is used as a catalyst, and a two-stage intermittent reaction is used for producing 1,2-propylene glycol. A glucose solution is injected into a high pressure reaction vessel, and a hydrogenolysis catalyst is added for initiating a reaction; a carrier MgO with alkalescence is used for replacing the added solid alkali, so that the reaction is carried out under a neutral condition; the two-stage intermittent reaction is carried out, thereby avoiding influence of the high temperature polymerization on the reaction, a hydrogenolysis/hydrogenation reaction of glucose is carried out at low temperature for generating an intermediate product; after heating, the intermediate product is reacted further; after cooling, filtering and separating of the product, a low carbon polyhydric alcohol whose main component is 1,2-propylene glycol is obtained. According to the invention, the concentration and the reaction selectivity of the reaction raw material are increased, and the requirement of the reaction equipment is reduced, and the operation safety coefficient of the apparatus is increased.

Description

A kind of method utilizing glucose to synthesize 1,2-PD

Technical field

The invention belongs to environment protection and energy technology field, relate to a kind of method that glucose hydrogenolysis prepares polyvalent alcohol.

Background technology

Along with fossil resource supplies being on the rise of the increasingly serious and environmental problem of form, developing the new renewable carbon utilization of resources has become very urgent problem.Biomass, as a kind of renewable resources of abundance, are translated into high valuable chemicals and have caused and pay close attention to widely.Carbohydrate is Mierocrystalline cellulose and starch in two kinds of main existence forms of occurring in nature, by heterogeneous catalyst, alleviates with the carbohydrate of biomass source and has realistic meaning to the dependence of conventional fossil raw material for raw material carrys out preparative chemistry product.By the technique early own industrialization of Starch Production glucose, and cellulosic technology for hydrolyzing there has also been significant progress in recent years.National Renewable Energy laboratory (NREL) adopts adverse current to shrink hydrolysis reactor, and in cellulosic hydrolysates, the productive rate of glucose can reach 84%.Therefore, in the process development realizing the Wood Adhesives from Biomass production energy and bulk chemical with Wood Adhesives from Biomass, based on glucose, raw material is most with prospects.

Propylene glycol is that important chemical manufactures Organic Chemicals, be widely used in fields such as producing unsaturated polyester vinegar resin, polyurethane resin, epoxy resin, Synolac, also be poly-cruel resin plasticizer simultaneously, extensive in sector applications such as essence and flavoring agent, makeup, medicine, cigarette.The Industrialized processing technique of propylene glycol is mainly based on the propylene oxide direct hydration method of petroleum path both at home and abroad at present, and this production technique is subject to raw material production capacity and price obviously, and technical process is long, and investment is large, and energy consumption is high.In addition as petroleum derivation chemical, discharge a large amount of carbonic acid gas in propylene oxide production process, be degrading Greenhouse effect, exacerbate the development that Global warming does not meet low-carbon economy.Therefore researching and developing with glucose is the operational path that principle produces large Chemicals, to substitute traditional operational path being raw material with non-renewable petroleum resources, China's development is in the future had to the meaning of particularly important.Following known technology, all comes with some shortcomings:

Chinese patent, publication number: CN101781171A, describes the method that dibasic alcohol prepared by nickel-molybdenum-copper-chromium catalyst catalytic hydrogenolysis glucose, has adding of alkali in its hydrogenolysis process, and hydrogen partial pressure is higher, there is very high requirement to the erosion resistance of equipment and stopping property.

Chinese patent, publication number: CN102020531A, describes Ni-W ₂the method of polyvalent alcohol prepared by C/CNFs catalyst hydrogenolysis glucose, and the concentration of its glucose is at about 1%-5%, and concentration is too low, is difficult to be applied to production.

Foreign patent, publication number: US4430253, describes the method that the Ru/C catalytic hydrocarbon utilizing sulfide to modify generates low-carbon polyol, is that raw material hydrogenolysis generates the yield of propylene glycol about 50% with glucose.But the price of Ru/C costly.

Summary of the invention

The invention provides adding problems such as the corrosion resistant requirements of equipment of a kind of method that glucose hydrogenolysis prepares the polyvalent alcohol too low and alkali for glucose concn, take 1,2-PD as target product, realize the directed recycling of glucose.Specifically, glucose solution is injected autoclave by the present invention, adds hydrogenolysis catalyst and reacts; Adopt two sections of rhythmic reactions, avoid high temperature polymerization on the impact of reaction, glucose generation hydrogenolysis/hydrogenation reaction under low temperature, generate intermediate: heat up afterwards, intermediate product reacts low-carbon polyols such as generating 1,2-PD further.After having reacted, reaction product adopts gas phase and liquid chromatography to carry out detection respectively and analyzes.Invention increases the concentration of reaction raw materials, reaction preference, reduce the requirement to conversion unit, increase plant running safety coefficient.

Technical scheme of the present invention is as follows:

Utilize glucose to synthesize a method for 1,2-PD, take D/W as raw material, in neutral conditions, add hydrogenolysis catalyst to it; Adopt two sections of rhythmic reactions, under first paragraph hydrogen pressure 5-8MPa condition, react 1-10h; Reaction product is able to through overcooling, filtration, separation the low-carbon polyol that 1,2-PD is master;

In described D/W, the mass percent of glucose is 5%-20%.

Described hydrogenolysis catalyst mass percent is 0.5-5wt%.

Described two intersegmental temperature of reaction of having a rest are first paragraph 120-140 DEG C, second segment 200-240 DEG C.

Described hydrogenolysis catalyst is Cu, Ni, CuNi metal catalyst, and carrier is the metal oxide MgO with alkalescence, and the mol ratio of metal component and carrier is 3:7.Wherein, NiCu catalyzer comprises the catalyzer that ambrose alloy mol ratio is 2:1,1:1,1:2,1:3,1:4 different ratios.The Main Function of catalyzer is catalysis glucose hydrogenation process under cold condition, and under hot conditions, the fracture of catalyzed carbon carbon bond generates low-carbon polyol.

Method of the present invention is not limited to pure D/W solution, is also applicable to industrial D/W as raw material.

Operating method of the present invention adopts two sections of rhythmic reactions, effectively prevents the generation of high-temperature coking.Adopt CuNi/MgO as hydrogenolysis catalyst, utilize the alkalescence of MgO carrier to replace the solid alkali added, avoid the corrosion of equipment, simple to operate.Under higher glucose concn, CuNi/MgO keeps higher activity.The invention solves the corrosion of solid alkali to equipment, increase plant running safety coefficient; Improve the concentration of glucose, realize its recycling.

Embodiment

Specific embodiments of the invention are described in detail below in conjunction with technical scheme.

Embodiment 1

Hydrogenolysis catalyst is loading type Cu, Ni, CuNi metal catalyst, and carrier adopts MgO, ZnO, and specific surface area of catalyst is at 200-300m ²/ g, pore volume is at 0.4-0.7cm ³/ g, mean pore size is distributed in 3-6nm.Metal precursor adopts nickelous nitrate, cupric nitrate, magnesium nitrate or zinc nitrate respectively.Coprecipitation method is adopted to prepare load type metal catalyst through steps such as precipitation-drying-roastings.At 30%, Mg/Zn metal, 70% is supported for Ni metal and Ni metal total mole of loading.

Glucose response result in following table 1 different catalysts

Reaction conditions: 10wt% D/W 30g, catalyzer 0.3g, Ca (OH) ₂0.08g, reaction pressure 6MPa, temperature of reaction 140 DEG C, reaction 2h, be warming up to 220 DEG C, reaction 3h.(in table, EG is ethylene glycol; 1,2-PD is 1,2-PD; GLY is glycerine)

As shown in Table 1, except Ni/ZnO catalyzer, create the phenomenon of coking, other catalyzer all shows more excellent catalytic performance.Wherein Cu/MgO catalyzer is optimum to the yield of 1,2-PD, and yield can reach 56%, Ni/MgO catalyzer and also show very high selectivity.

Embodiment 2

Have alkalescence based on MgO, the alkalescence investigating carrier in Cu/MgO, Ni/MgO catalyzer respectively replaces solid alkali Ca (OH) ₂to the effect of C-C fracture.Following table 2 is shown in and does not add the impact of solid alkali on reaction result.

^aca (OH) ₂0.08g; ^bdo not add Ca (OH) ₂.Remaining reaction conditions: 10wt% D/W 30g, catalyzer 0.3g, reaction pressure 6MPa, temperature of reaction 140 DEG C, reaction 2h, is warming up to 220 DEG C, reaction 3h.(in table, EG is ethylene glycol; 1,2-PD is 1,2-PD; GLY is glycerine)

As shown in Table 2, in the glucose hydrogenolysis of lower concentration, the yield of 1,2-PD slightly reduces, and the alkalescence of MgO can replace fraction solids alkali Ca (OH) ₂playing the effect promoting C-C fracture, improving the yield of 1,2-PD by changing reaction conditions.

Embodiment 3

Based on Cu/MgO, Ni/MgO catalyst glucose hydrogenolysis, all there is higher selectivity, consider that the CuNi/MgO of different metal ratio is on the impact of glucose hydrogenolysis.Following table 3 is shown in the reaction result of the CuNi/MgO catalysis glucose hydrogenolysis of different metal ratio.

Reaction conditions: 10wt% D/W 30g, catalyzer 0.3g, do not add Ca (OH) ₂, reaction pressure 6MPa, temperature of reaction 140 DEG C, reaction 2h, be warming up to 220 DEG C, reaction 3h.(in table, EG is ethylene glycol; 1,2-PD is 1,2-PD; GLY is glycerine)

As can be seen from Table 3, relative to other catalyzer, the catalytic activity of 1Ni4Cu/MgO catalyzer is relatively higher, and the yield of 1,2-PD reaches 46.7%.PRELIMINARY RESULTS display 1Ni4Cu/MgO catalyzer has certain potentiality to conversion of glucose.

Embodiment 4

Based on the glucose of 1Ni4Cu/MgO catalyzer to lower concentration, there is good catalytic activity, so investigate the catalytic activity of catalyzer for the glucose solution of high density.Following table 4 is shown in the reaction result of 1Ni4Cu/MgO catalysis different glucose hydrogenolysis.

Reaction conditions: 1Ni4Cu/MgO catalyzer 0.3g, do not add Ca (OH) ₂, reaction pressure 6MPa, temperature of reaction 140 DEG C, reaction 2h, be warming up to 220 DEG C, reaction 3h.(in table, EG is ethylene glycol; 1,2-PD is 1,2-PD; GLY is glycerine)

Increase glucose concn to 15wt%, the yield of 1,2-PD slightly increases.Continuing the concentration of increase glucose to 20wt%, there is coking in product, and the yield of 1,2-PD declines, and this is relevant with the formation of water soluble polymer.Therefore, the reaction parameter of the hydrogenolysis of high concentration glucose (20wt%) is optimized.Embodiment 5

Based on the important factor that temperature is glucose hydrogenolysis, investigate the impact of second segment temperature of reaction on reaction.Following table 5 is shown in that second segment temperature of reaction affects the reaction of glucose hydrogenolysis.

Reaction conditions: 20wt% D/W 30g, 1Ni4Cu/MgO catalyzer 0.3g, do not add Ca (OH) ₂, reaction pressure 6MPa, react 2h under first paragraph temperature of reaction, be warming up to 220 DEG C, reaction 3h.(in table, EG is ethylene glycol; 1,2-PD is 1,2-PD; GLY is glycerine)

Following table 6 is shown in that first paragraph temperature of reaction affects the reaction of glucose hydrogenolysis.

Reaction conditions: 20wt% D/W 30g, 1Ni4Cu/MgO catalyzer 0.3g, do not add Ca (OH) ₂, reaction pressure 6MPa, temperature of reaction 140 DEG C, reaction 2h, react 3h under second segment temperature of reaction.(in table, EG is ethylene glycol; 1,2-PD is 1,2-PD; GLY is glycerine)

As can be seen from table 5,6, along with the yield of first and second section of temperature of reaction to 1,2-PD has a certain impact.Adopt the process of two step hydrogenolysis, effectively can avoid the generation of coking process.When first paragraph temperature of reaction 140 DEG C, second segment temperature of reaction at 200 DEG C time, the yield of 1,2-PD is relatively better.Embodiment 6

Consider the important factor of reaction pressure as glucose hydrogenolysis.Following table 7 is shown in the impact of different pressures on glucose hydrogenolysis.

Reaction conditions: 20wt% D/W 30g, 1Ni4Cu/MgO catalyzer 0.3g, do not add Ca (OH) ₂, temperature of reaction 140 DEG C, reaction 2h, be warming up to 200 DEG C, reaction 3h.(in table, EG is ethylene glycol; 1,2-PD is 1,2-PD; GLY is glycerine)

When pressure is elevated to 8MPa, the impact of rising on hydrogenolysis of pressure becomes not obvious.And under high pressure, easily make low-carbon polyol as the transition hydrogenolysis of 1,2-PD, thus reduce its selectivity.

Claims (4)

1. utilize glucose to synthesize a method for 1,2-PD, it is characterized in that:

Take D/W as raw material, in neutral conditions, add hydrogenolysis catalyst to it; Adopt two sections of rhythmic reactions, under first paragraph hydrogen pressure 5-8MPa condition, react 1-10h; Reaction product is able to through overcooling, filtration, separation the low-carbon polyol that 1,2-PD is master;

In described D/W, the mass percent of glucose is 5%-20%;

Described hydrogenolysis catalyst mass percent is 0.5-5wt%;

Described two intersegmental temperature of reaction of having a rest are first paragraph 120-140 DEG C, second segment 200-240 DEG C.

2. method according to claim 1, is characterized in that: described hydrogenolysis catalyst is Cu, Ni, CuNi metal catalyst, and carrier is the metal oxide MgO with alkalescence, and the mol ratio of metal component and carrier is 3:7.

3. method according to claim 2, is characterized in that: NiCu catalyzer comprises the catalyzer that ambrose alloy mol ratio is 2:1,1:1,1:2,1:3 or 1:4.

4. the method according to claim 1,2 or 3, is characterized in that: described D/W is pure glucose solution or industrial D/W.