CN101899318A - A kind of method for preparing diesel oil hydrocarbons by catalytic hydrodeoxygenation of vegetable oil - Google Patents

Abstract

The invention discloses a method for preparing diesel hydrocarbons from vegetable fat through catalytic hydrogenation and deoxygenation, is a method for preparing alkane with a high calorific value from vegetable fat through catalytic hydrogenation and deoxygenation, and adopts a one-pot method reaction process, comprising the following steps: adding a molybdenum carbide catalyst, vegetable fact and solvent in a reactor, filling hydrogen in the reactor, stirring and heating, reacting for 3-10h with the reaction pressure of 1-10MPa and the reaction temperature of 250-350 DEG C, stopping reaction, cooling to room temperature, filtering and separating the catalyst out to obtain the diesel hydrocarbons with alkane at a high calorific value. By adopting the technical scheme in the invention, the method has low production cost and high product combustion value, is favor of large-scale industrialized popularization and is a clean and regenerative diesel alternative fuel.

Description

A kind of method for preparing diesel oil hydrocarbons by catalytic hydrodeoxygenation of vegetable oil

technical field

The present invention relates to a method based on catalytic hydrodeoxygenation of vegetable fats and oils to produce diesel hydrocarbons, more specifically, to a method based on non-noble metal-based catalysts to prepare diesel hydrocarbons by catalytic hydrodeoxygenation of vegetable fats and oils

Background technique

With the sustained and rapid development of my country's national economy, the demand for liquid fuels has grown rapidly. It is estimated that by 2020, my country's oil supply gap will reach 250 million tons, and the dependence on foreign oil will reach 54%. The development of liquid fuels with sustainable sources to replace petroleum is of great significance to alleviate the current situation of my country's oil shortage, and to ensure my country's energy security and sustainable development of the national economy. It is a long-term major demand for my country in the future. Animal and vegetable oils are a class of substances that widely exist in nature, such as rapeseed oil, coconut oil, palm oil, soybean oil, peanut oil, leprosy oil, tallow oil, etc. Its main components are free fatty acids and glycerides of saturated or unsaturated fatty acids, which are renewable resources. The free fatty acids contained in animal and vegetable oils and fats are mainly palmitic acid containing 16 carbon atoms, stearic acid, oleic acid, linoleic acid and linolenic acid containing 18 carbon atoms; the ester compounds contained in animal and vegetable oils and fats are mainly Monoglycerides, diglycerides and triglycerides obtained from the esterification of palmitic acid, stearic acid, oleic acid, linoleic acid or linolenic acid with glycerol. Although animal and vegetable oils are abundant, glycerides have high oxygen content and high viscosity, and free fatty acids are highly corrosive to engines, so animal and vegetable oils cannot be directly used as fuel for engines.

Diesel oil is mainly composed of alkanes, olefins, naphthenes, etc. containing 10 to 22 carbon atoms. It has a high combustion calorific value and is an excellent fuel for heavy equipment. In view of the common characteristics of animal and vegetable oils and diesel in terms of structural composition (both contain long carbon chains), the clean renewable diesel hydrocarbons can be obtained by converting animal and vegetable oils into alkanes through hydrodeoxygenation, the so-called Second generation biodiesel. Compared with fossil fuels, the liquid fuel produced from energy crops is renewable and is a real "green energy". It can not only alleviate the shortage of oil supply, but also increase farmers' income and protect the ecological environment. It has three advantages with one stone. bird meaning.

The transformation of bio-oil extracted from renewable rapeseed, castor, soybean, cotton, jatropha and other agricultural and forestry crops into available liquid fuel for internal combustion engines has attracted more and more attention from governments and scholars (US Patent: US2009077867, 2009; US Patent: US20100000908, 2010; P. Simacek, et al, Fuel, 2009, 88, 456.). The currently reported catalysts for oil hydrodeoxygenation are mainly noble metal-based catalysts such as Pt and Pd. Such catalysts are limited in large-scale industrial application due to their high price and limited reserves. Molybdenum carbide has a noble metal-like valence shell electronic structure and exhibits catalytic activity similar to that of noble metals in many hydrogen-related reactions. Due to the easy availability and low price of molybdenum carbide synthesis raw materials, it is of great theoretical and practical significance to use it as a substitute catalyst for noble metals such as Pt and Pd in the field of the preparation of renewable diesel hydrocarbons.

Contents of the invention

The purpose of the present invention is to solve the above problems, to provide a catalyst that is easy to synthesize and cheap; the product has a high calorific value of combustion, and is a clean and renewable diesel alternative fuel; the solvent is cheap and easy to obtain, with less consumption, low boiling point, and easy recovery The invention discloses a method for preparing diesel hydrocarbons through catalytic hydrodeoxygenation of vegetable oils.

Technical scheme of the present invention is such:

A method for preparing diesel hydrocarbons by catalytic hydrodeoxygenation of vegetable fats and oils, wherein high calorific value alkanes are obtained by catalytic hydrodeoxygenation of vegetable fats and oils, which is prepared by a one-pot reaction process;

Methods as below:

In the reactor, add catalyst, vegetable oil and solvent, fill with hydrogen, start stirring and heating, the reaction pressure is 1-10MPa, the reaction temperature is 250-350°C, stop the reaction after 3-10 hours, and wait to cool to room temperature Finally, filter and separate the catalyst to obtain diesel hydrocarbons containing high calorific value alkanes.

Preferably, the catalyst is a molybdenum carbide catalyst supported by activated carbon, and the active component molybdenum carbide has a mass percentage of 5-30%.

Preferably, the active component molybdenum carbide has a mass percentage of 15-25%.

Preferably, the solvent may be n-hexane or n-heptane or n-octane or dodecane or hexadecane.

Preferably, the solvent used in the catalytic hydrodeoxygenation reaction of vegetable oil is n-hexane.

As a preference, the vegetable oil used can be sunflower oil or rapeseed oil or soybean oil or corn oil or olive oil.

Preferably, the weight ratio of the catalyst to the vegetable oil is 1:2˜1:10; the weight volume ratio of the vegetable oil to the solvent is 1 g:10 mL˜1 g:35 mL.

Preferably, the catalytic hydrodeoxygenation reaction pressure of vegetable oil is 2-6 MPa.

Preferably, the catalytic hydrodeoxygenation reaction temperature of vegetable oil is 270-320°C.

The beneficial effects of the present invention are as follows:

1. Use cheap and easy-to-obtain molybdenum carbide materials instead of expensive Pt, Pd and other noble metal catalysts, which greatly reduces production costs and is conducive to large-scale industrialization.

2. Compared with noble metal catalysts such as Pt and Pd, after hydrodeoxygenation of vegetable oils on molybdenum carbide catalysts, non-decarbonylation products are mainly produced, and the carbon chains of oils are not cracked, and the selectivity to target products is good. Therefore, the product has a high combustion calorific value and is a clean and renewable diesel alternative fuel.

3. Compared with the preparation process of biodiesel, no glycerol is produced during the hydrodeoxygenation process of vegetable oils, and there is no need to neutralize excessive acid and alkali catalysts after the reaction, thus effectively avoiding the increase in production costs caused by post-treatment.

4. The solvent is cheap and easy to obtain, less dosage, low boiling point, easy to recycle.

Detailed ways

Technical scheme of the present invention is such:

A method for preparing diesel hydrocarbons by catalytic hydrodeoxygenation of vegetable fats and oils, wherein high calorific value alkanes are obtained by catalytic hydrodeoxygenation of vegetable fats and oils, which is prepared by a one-pot reaction process;

Methods as below:

In the reactor, add catalyst, vegetable oil and solvent, fill with hydrogen, start stirring and heating, the reaction pressure is 1-10MPa, the reaction temperature is 250-350°C, stop the reaction after 3-10 hours, and wait to cool to room temperature Finally, filter and separate the catalyst to obtain diesel hydrocarbons containing high calorific value alkanes.

The catalyst is a molybdenum carbide catalyst supported by active carbon, and the mass percentage of molybdenum carbide as an active component is 5-30%. In order to achieve a more ideal effect, the mass percent content of molybdenum carbide as the active component can be 15-25%.

The solvent may be n-hexane or n-heptane or n-octane or dodecane or hexadecane.

During the implementation, the solvents used in the catalytic hydrodeoxygenation reaction of vegetable oils are n-hexane, n-heptane, n-octane, dodecane and hexadecane respectively.

The vegetable oil used may be sunflower oil or rapeseed oil or soybean oil or corn oil or olive oil.

The weight ratio of the catalyst to the vegetable oil is 1:2-1:10; the weight-volume ratio of the vegetable oil to the solvent is 1g:10mL-1g:35mL.

In order to achieve a more ideal effect, the reaction pressure of vegetable oil catalytic hydrodeoxygenation is 2-6MPa.

In order to achieve a more ideal effect, the catalytic hydrodeoxygenation reaction temperature of vegetable oil is 270-320°C.

Example 1

Add 0.2g of Mo2C/AC catalyst, 1.0g of sunflower oil and 20mL of n-hexane into a 100mL reactor, fill it with hydrogen, start stirring and heating at an initial hydrogen pressure of 2.5MPa, stop the reaction after 10 hours at 270°C, and wait to cool to After room temperature, the catalyst was separated by filtration to obtain clear and transparent diesel hydrocarbons. Quantitative detection of the product by high-performance liquid chromatography and gas chromatography shows that the conversion rate of the raw material sunflower oil can reach 97%, and the total output of diesel hydrocarbons is 0.61g.

The product composition is shown in the table below:

Example 2

Add 0.4g of Mo2C/AC catalyst, 2.0g of olive oil and 30mL of n-octane into a 100mL reaction kettle, fill it with hydrogen, start stirring and heating at an initial hydrogen pressure of 4.0MPa, stop the reaction after 6 hours at 320°C, and wait to cool to After room temperature, the catalyst was separated by filtration to obtain clear and transparent diesel hydrocarbons. Quantitatively detect the product by high performance liquid chromatography and gas chromatography respectively, it can be seen that the conversion rate of the raw material olive oil can reach 100%, and the total output of diesel oil hydrocarbons is 1.44g.

The product composition is shown in the table below:

Example 3

Add 0.25g of Mo2C/AC catalyst, 1.5g of corn oil and 25mL of n-heptane into a 100mL reactor, fill it with hydrogen, start stirring and heating at an initial hydrogen pressure of 2.5MPa, and stop the reaction at 290°C for 8 hours, then cool to After room temperature, the catalyst was separated by filtration to obtain clear and transparent diesel hydrocarbons. Quantitative detection of the product by high-performance liquid chromatography and gas chromatography respectively shows that the conversion rate of raw material corn oil can reach 100%, and the total output of diesel hydrocarbons is 1.00g.

The product composition is shown in the table below:

Example 4

Add 0.2g Mo2C/AC catalyst, 1.5g rapeseed oil and 15mL dodecane to 100

In the mL reactor, fill with hydrogen, the initial hydrogen pressure is 3.5MPa, start stirring and heating, stop the reaction after 4 hours of reaction at 300 °C, and after cooling to room temperature, filter and separate the catalyst to obtain clear and transparent diesel hydrocarbons. Quantitative detection of the product by high performance liquid chromatography and gas chromatography respectively shows that the conversion rate of the raw material rapeseed oil can reach 98%, and the total output of diesel hydrocarbons is 0.94g.

The product composition is shown in the table below:

Example 5

Add 0.3g of Mo2C/AC catalyst, 2.0g of soybean oil and 20mL of hexadecane into a 100mL reactor, fill it with hydrogen, start stirring and heating at an initial hydrogen pressure of 4.0MPa, stop the reaction after 7 hours at 310°C, and wait to cool to After room temperature, the catalyst was separated by filtration to obtain clear and transparent diesel hydrocarbons. Quantitative detection of the product by high-performance liquid chromatography and gas chromatography respectively shows that the conversion rate of the raw material soybean oil can reach 99%, and the total output of diesel hydrocarbons is 1.34g.

The product composition is shown in the table below:

What has been described above is only a preferred embodiment of the present invention. It should be pointed out that for those of ordinary skill in the art, some improvements and modifications can be made without departing from the core technical features of the present invention. Improvements and retouches should also be considered within the protection scope of the present invention.

Claims (9)

1. a Vegetable oil lipoprotein catalytic hydrodeoxygenation prepares the method for diesel hydrocarbons, is that Vegetable oil lipoprotein makes high heating value alkane through catalytic hydrodeoxygenation, it is characterized in that, adopts the preparation of one kettle way reaction process;

Method is as follows:

In reactor, add catalyzer, Vegetable oil lipoprotein and solvent, charge into hydrogen, open and stir and heating, reaction pressure is 1-10MPa, temperature of reaction is 250-350 ℃, react stopped reaction after 3-10 hour, to be cooled to room temperature, filter to isolate the diesel hydrocarbons that catalyzer can obtain containing high heating value alkane.

2. Vegetable oil lipoprotein catalytic hydrodeoxygenation according to claim 1 prepares the method for diesel hydrocarbons, it is characterized in that, described catalyzer is activated carbon supported molybdenum carbide catalyst, and the quality percentage composition of active ingredient molybdenum carbide is 5-30%.

3. Vegetable oil lipoprotein catalytic hydrodeoxygenation according to claim 1 prepares the method for diesel hydrocarbons, it is characterized in that, described solvent can be normal hexane or normal heptane or octane or dodecane or n-Hexadecane.

4. Vegetable oil lipoprotein catalytic hydrodeoxygenation according to claim 2 prepares the method for diesel hydrocarbons, it is characterized in that, the quality percentage composition of active ingredient molybdenum carbide is 15～25%.

5. Vegetable oil lipoprotein catalytic hydrodeoxygenation according to claim 1 prepares the method for diesel hydrocarbons, it is characterized in that, used Vegetable oil lipoprotein can be sunflower seed oil or rapeseed oil or soybean oil or Semen Maydis oil or sweet oil.

6. Vegetable oil lipoprotein catalytic hydrodeoxygenation according to claim 1 prepares the method for diesel hydrocarbons, it is characterized in that, the weight ratio of catalyzer and Vegetable oil lipoprotein is 1: 2～1: 10; The weightmeasurement ratio of vegetables oil and solvent is 1g: 10mL～1g: 35mL.

7. Vegetable oil lipoprotein catalytic hydrodeoxygenation according to claim 1 prepares the method for diesel hydrocarbons, it is characterized in that, Vegetable oil lipoprotein catalytic hydrodeoxygenation reaction pressure is 2-6MPa.

8. Vegetable oil lipoprotein catalytic hydrodeoxygenation according to claim 1 prepares the method for diesel hydrocarbons, it is characterized in that, Vegetable oil lipoprotein catalytic hydrodeoxygenation temperature of reaction is 270-320 ℃.

9. Vegetable oil lipoprotein catalytic hydrodeoxygenation according to claim 1 prepares the method for diesel hydrocarbons, it is characterized in that, Vegetable oil lipoprotein catalytic hydrodeoxygenation reaction solvent for use is a normal hexane.