WO2019000819A1

WO2019000819A1 - METHOD FOR PREPARING LIQUID FUEL WITH γ-VALEROLACTONE

Info

Publication number: WO2019000819A1
Application number: PCT/CN2017/112483
Authority: WO
Inventors: 康世民; 杨其飞; 杨学斯; 王泽潘; 谭炯豪
Original assignee: 东莞理工学院
Priority date: 2017-06-27
Filing date: 2017-11-23
Publication date: 2019-01-03
Also published as: CN107083254B; US20200148958A1; CN107083254A

Abstract

A method for preparing liquid fuel with γ-valerolactone, comprising the following steps: putting a phosphoric acid solution and γ-valerolactone in a reaction tank; reacting for 3-12 h at the temperature of 220-260°C, and cooling to the room temperature to obtain liquid fuel. The phosphoric acid solution serves as a catalyst, γ-valerolactone can be catalytically converted in one step at mild temperature to prepare high-calorific-value light oil and heavy oil products, and the total oil yield can reach up to 33.5 wt%. This technique has simple process flow, is convenient to operate, and has industrial application prospect. Compared with other techniques for preparing high-grade oil products by catalytically convertingγ-valerolactone, catalytic conversion of the phosphoric acid solution has the obvious advantages that no expensive hydrogen needs to be provided externally, the reaction process is simple, and the temperature is mild.

Description

Method for preparing liquid fuel by using γ-valerolactone

Technical field

The invention relates to the technical field of preparation of renewable liquid fuel, in particular to a method for preparing high-grade liquid fuel by catalytically converting γ-valerolactone by using a phosphoric acid solution.

Background technique

With the depletion of petrochemical resources, the development and utilization of renewable biomass liquid fuels is an important means of solving the energy crisis. Γ-valerolactone is an important bio-based platform compound which can be hydrolyzed by cellulose acid in plants to form levulinic acid, which is obtained by hydrogenation of levulinic acid and self-esterification. However, γ-valerolactone has high water solubility and low calorific value, which greatly limits its application as a high-grade vehicle fuel. A possible method of using γ-valerolactone is to convert it into a hydrocarbon-based liquid fuel of moderate molecular weight, which can be used to replace petrochemical gasoline (mainly C4-C12) or diesel (C10-C22). Since γ-valerolactone is a low molecular compound (C ₅ H ₈ O ₂ ) containing an ester bond, its conversion to a high-grade liquid fuel requires a multi-step reaction including a hydrodeoxygenation reaction and an acid-catalyzed oligomerization reaction. In general, the γ-valerolactone hydrodeoxygenation reaction requires a higher reaction temperature (e.g., 300 ° C) and a higher pressure (e.g., 35 MPa). The high price of hydrogen in the hydrogenation process is an important factor limiting the preparation of high-grade liquid fuels from γ-valerolactone. In addition, the multi-step reaction required during the conversion of γ-valerolactone and the higher temperature also cause high Process cost. Therefore, the development of a new type of catalytic reaction system, one-step conversion of γ-valerolactone as a high-grade liquid fuel without hydrogenation and mild temperature is of great significance.

Summary of the invention

The invention provides a method for converting γ-valerolactone into a high-grade liquid fuel under mild conditions by using a 100% phosphoric acid solution as a catalyst, thereby solving the current need for preparing high-grade liquid fuel by using γ-valerolactone. Step reaction process and harsh reaction conditions (such as high temperature, catalytic hydrogenation, etc.).

The technical scheme for realizing the invention is: a method for preparing a liquid fuel by using γ-valerolactone, the steps are as follows: a phosphoric acid solution and γ-valerolactone are placed in a reaction tank, and reacted at 220-260 ° C for 3-12 h. Cool to room temperature to obtain a liquid fuel.

The phosphoric acid solution has a mass concentration of 100%.

The mass ratio of the γ-valerolactone to the phosphoric acid solution is 1: (2-100).

The phosphoric acid solution and γ-valerolactone were placed in a reaction tank, and the temperature was raised to 220-260 ° C at 5-10 ° C / min.

Preferably, the method for preparing a liquid fuel using γ-valerolactone is as follows:

(1) γ-valerolactone, phosphoric acid solution is placed in a reaction tank, reacted at 220-260 ° C for 3-12 h, the reaction is completed and then cooled to room temperature to obtain a liquid fuel;

(2) rotating the liquid fuel cooled in step (1) to obtain an oil-water mixture and a phosphoric acid mixture, separating the oil-water mixture oil-water to obtain light oil, the rotary evaporation temperature is 240 ° C, and the pressure is -0.09 MPa;

(3) The phosphoric acid mixture obtained in the step (2) was extracted with dichloromethane, and the extracted dichloromethane solution was subjected to a rotary evaporator to obtain dichloromethane and heavy oil. The rotary evaporation temperature was 60 ° C and the pressure was -0.09 MPa.

The light oil has a boiling point of ≤240 ° C and a heavy oil has a boiling point of ≥ 240 ° C.

The temperature and pressure critical conditions for the separation of the obtained light oil and heavy oil are 240 ° C, -0.09 MPa. Based on the correspondence between the boiling point and the pressure, the boiling point of the light oil is ≤ 245 ° C under normal pressure, and the boiling point of heavy oil is ≥ 245 ° C.

The main reaction pathway for the catalytic conversion of γ-valerolactone to liquid fuel is shown in the figure below. In an acidic solution, the conversion of γ-valerolactone to 4-hydroxyvaleric acid is a reversible reaction, while 4-hydroxyvaleric acid can be dehydrated to form 3-pentenoic acid under heating acid catalysis. Using 100% phosphoric acid as catalyst and γ-valerolactone and 3-pentenoic acid as reaction materials, respectively, it was found that the products were completely consistent, which proved that 3-pentenoic acid is a kind of γ-valerolactone converted into liquid fuel. Important intermediates. After the reaction, CO ₂ and 2-butene were detected in the gas product by top air mass spectrometry, indicating that the decarboxylation reaction of 3-pentenoic acid occurred; at the same time, CO ₂ , water and some produced during the reaction. The unsaturated ketone compound indicates that 3-pentenoic acid undergoes a ketonization reaction during the reaction. Under the catalysis of phosphoric acid, aromatic cyclization, alkylation, oligomerization, etc., between aromatic ketone compounds and unsaturated ketone compounds and 2-butene further form aromatic compounds and cyclic hydrocarbons. Class of compounds.

The main reaction pathway for the conversion of γ-valerolactone to hydrocarbons

The beneficial effects of the invention are:

(1) Using a phosphoric acid solution as a catalyst, a high calorific value of light oil and heavy oil product can be obtained by one-step catalytic conversion of γ-valerolactone at a mild temperature (220-260 ° C), and the total oil yield can be as high as 31 wt%. The process is simple, easy to operate, and has industrial application prospects;

(2) The mass fractions of light oil C and H are 88.0% and 8.9%, respectively, and the calorific value is up to 42.4MJ/kg; the mass fractions of heavy oil products C and H are as high as 85.7% and 9.5%, respectively, and the calorific value is as high as 41.6MJ/kg; The calorific value of oil and heavy oil is comparable to the calorific value of commercial oxygenated gasoline (see Table 1).

(3) Under the catalysis of phosphoric acid, part of the oxygen in γ-valerolactone is removed in the form of carbon dioxide, and the decarboxylation rate is 49%;

(4) Compared with other catalytic conversion γ-valerolactone to prepare high-grade oil product technology, phosphoric acid solution catalytic conversion has no need The external supply of expensive hydrogen, the reaction process is simple (one-step reaction), the temperature is mild (temperature below 260 ° C) has obvious advantages.

DRAWINGS

Figure 1 is a process flow diagram of the present invention.

Figure 2 is a light oil and gas chromatography analysis product of Example 1.

3 is an infrared spectrum spectrum of light oil and heavy oil in Example 1.

Detailed ways

Example 1

The specific steps of the present embodiment for preparing liquid fuel by catalytic conversion of poly-3-hydroxybutyrate with phosphoric acid are as follows (the flow chart is shown in Figure 1):

(1) 15 g of γ-valerolactone and 60 mL of a phosphoric acid solution (112.2 g) were placed in a 100 mL para-polyphenyl reaction tank. The temperature was raised to 240 ° C at 5 ° C / min, and kept at 240 ° C for 6 h. After the reaction, it was rapidly cooled to room temperature with cold water. The high-performance liquid chromatography showed that γ-valerolactone was almost completely converted, of which γ-pentane 49% of the oxygen in the ester is removed by carbon dioxide formation, and part of the oxygen is removed as water and carbon monoxide;

(2) After the reaction of the step (1), the product is rotary-evaporated at 240 ° C, -0.09 Mpa to obtain an oil-water mixture and a phosphoric acid mixture. The oil-water mixture is separated by a separating funnel to obtain a light oil, and the light oil yield is 24.8 wt. %;

(3) The evaporated phosphoric acid mixture obtained in the step (2) is extracted with dichloromethane, and the extracted dichloromethane solution is subjected to rotary distillation at 60 ° C, -0.09 Mpa to recover dichloromethane. And obtained heavy oil, heavy oil yield 8.7%.

The hydrogen oil and heavy oil yields obtained in this example, the distribution of C and H elements and the calorific value are shown in Table 1.

Table 1 Light oil and heavy oil yield, C, H element distribution and calorific value

Fig. 2 is a molecular structural formula of the main product identified by gas chromatography analysis of the prepared light oil product. As can be seen from Fig. 2, the main product is a low molecular unsaturated benzene ring compound, a cyclic hydrocarbon compound.

The main products in Figure 2 were further verified by infrared spectroscopy of the light oil product of Figure 3. From Figure 3, it can be seen that the light oil product contains CH vibration peaks including methyl, methylene and methine groups (2800). -3100cm ^-1 ) and aromatic ring functional groups (1600cm ^-1 , 1460cm ^-1 ); there is no obvious vibration peak at 3200-3670cm ^-1 , indicating that there are substantially no hydroxyl and carboxyl functional groups in the oil product, and γ-valerolactone is successfully decarboxylated; There is a small vibration peak at 1780 cm ^-1 , indicating that the oil product contains a small amount of ketone compound, which is consistent with the GCMS analysis in Figure 2; in addition, the infrared spectrum of heavy oil is basically similar to light oil, indicating that the main oil is heavy. The components also include CH functional groups and aryl functional groups including methyl, methylene and methine groups.

Example 2

15 g of γ-valerolactone and 15 mL of phosphoric acid solution (28 g) were placed in a 100 mL para-polyphenyl reaction tank. The temperature was programmed to 260 ° C, and maintained at 260 ° C for 6 h. After the reaction was completed, it was cooled to room temperature, and light oil was obtained by rotary evaporation, and then extracted by dichloromethane and distilled to obtain a heavy oil.

Example 3

1 g of γ-valerolactone and 50 mL of a phosphoric acid solution (93.7 g) were placed in a 100 mL para-polyphenyl reaction tank. The temperature was raised to 220 ° C at 8 ° C / min, and kept at 220 ° C for 12 h. After the reaction was completed, it was cooled to room temperature, and light oil was obtained by rotary evaporation, and then extracted by dichloromethane and distilled to obtain a heavy oil.

Example 4

10 g of γ-valerolactone and 60 mL of phosphoric acid solution were placed in a para-polyphenyl reaction tank. The temperature was programmed to 10 ° C / min to 250 ° C, and maintained at 250 ° C for 3 h, after the reaction was cooled to room temperature, by rotary evaporation to obtain light oil, and then extracted by dichloromethane and distilled to obtain a heavy oil.

Example 5

1 g of γ-valerolactone and 1.07 mL of a 100% strength phosphoric acid solution (2 g) were placed in a 20 mL para-polyphenyl reaction tank, and the temperature was programmed to 10 ° C / min to 260 ° C for 5 h, and then cooled to room temperature after completion of the reaction. The light oil is obtained by rotary evaporation, and then extracted and distilled through dichloromethane to obtain a heavy oil.

Example 6

1 g of γ-valerolactone and 53.4 mL of a 100% strength phosphoric acid solution (100 g) were placed in a para-polyphenyl reaction tank, and the temperature was programmed to 5° C./min to 230° C. for 8 h, and then cooled to room temperature after completion of the reaction. The light oil is obtained by rotary evaporation, and then extracted and distilled through dichloromethane to obtain a heavy oil.

Example 7

1 g of γ-valerolactone and 26.7 mL of a 100% strength phosphoric acid solution (50 g) were placed in a para-polyphenyl reaction tank, and the temperature was programmed to 10 ° C / min to 260 ° C for 5 h, and then cooled to room temperature after completion of the reaction. The light oil is obtained by rotary evaporation, and then extracted and distilled through dichloromethane to obtain a heavy oil.

Claims

A method for preparing a liquid fuel by using γ-valerolactone, which is characterized in that the steps are as follows: a phosphoric acid solution and γ-valerolactone are placed in a reaction tank, reacted at 220-260 ° C for 3-12 h, and cooled to room temperature. Liquid fuel.
The method for producing a liquid fuel using γ-valerolactone according to claim 1, wherein the phosphoric acid solution has a mass concentration of 100%.
The method for producing a liquid fuel using γ-valerolactone according to claim 1, wherein the mass ratio of the γ-valerolactone to the phosphoric acid solution is 1: (2-100).
The method for preparing a liquid fuel by using γ-valerolactone according to claim 1, wherein a phosphoric acid solution and γ-valerolactone are placed in a reaction tank, and the temperature is raised to 220-260 at 5-10 ° C / min. °C.
A method of preparing a liquid fuel using γ-valerolactone according to any of claims 1-4, characterized in that the steps are as follows:

(1) γ-valerolactone, phosphoric acid solution is placed in a reaction tank, reacted at 220-260 ° C for 3-12 h, the reaction is completed and then cooled to room temperature to obtain a liquid fuel;

(2) rotating the liquid fuel cooled in step (1) to obtain an oil-water mixture and a phosphoric acid mixture, separating the oil-water mixture oil-water to obtain light oil, the rotary evaporation temperature is 240 ° C, and the pressure is -0.09 MPa;

(3) The phosphoric acid mixture obtained in the step (2) is extracted with dichloromethane, and the extracted dichloromethane solution is distilled by a rotary evaporator to obtain dichloromethane and heavy oil. The temperature of the rotary evaporator is 60 ° C, and the pressure is -0.09. MPa.
The method for preparing a liquid fuel using γ-valerolactone according to claim 5, wherein the step is as follows: at normal pressure, the light oil has a boiling point of ≤ 245 ° C and the heavy oil has a boiling point of ≥ 245 ° C.