CN104016826A - Method for preparing alkane from halohydrocarbon - Google Patents

Abstract

A method for preparing alkanes from halogenated hydrocarbons, involving hydrocarbon compounds. React halogenated hydrocarbons, metals and initiators, collect liquid phase products, and obtain alkanes after separation. The reaction of metals and halogenated hydrocarbons realizes the conversion of halogenated hydrocarbons. The whole reaction conditions are mild and do not require noble metal catalysts, hydrogen, high temperature, high pressure, organic matter extraction agent process, etc., and the preparation method of hydrocarbon fuels from non-petrochemical sources is used. The entire production The process energy consumption is low, the product quality is good, and it has good application prospects. The preparation process is simple, the operation is convenient, and the efficiency is high, and the prepared hydrocarbon fuel belongs to the category of clean renewable energy and typical "green energy".

Description

A method for preparing alkanes from halogenated hydrocarbons

technical field

The present invention relates to hydrocarbon compounds, in particular to a method for preparing alkanes from halogenated hydrocarbons.

Background technique

As the technology of producing polyols by catalytic conversion of biomass becomes increasingly mature, the preparation of hydrocarbons from polyols also shows its development potential. It has been reported in the literature that sorbitol derived from biomass can be catalytically converted into C ₆ -C ₉ hydrocarbons, but the reaction process is complicated, the catalyst is expensive, and the reaction temperature is high. However, U.S. Patent No. 5,516,960 discloses a method for preparing hydrocarbons by reacting sorbitol, hydroiodic acid, phosphorous acid, and water under relatively mild conditions. The products obtained are C ₁₀ -C ₁₈ hydrocarbons, and the by-product is iodine alkanes and iodine. The method for removing the iodoalkane is to react the iodoalkane with the alcohol solution of the alkali to form alkenes, and then add hydrogen to form alkanes under high temperature and high pressure conditions.

Direct catalytic hydrogenation is also a common method for hydrogenolysis and dehalogenation of halogenated hydrocarbons. The catalysts used are generally nickel and palladium, but these two catalysts are usually used in large amounts or difficult to recycle. Chinese patent CN1974498A discloses a method for preparing hydrocarbons by catalytic hydrogenation reduction of halogenated hydrocarbons for dehalogenation. The method has mild reaction conditions and the catalyst can be recycled, but the catalyst used is a palladium salt catalyst, and the process requires hydrogen. In short, these common treatment processes basically require hydrogen and noble metal catalysts, resulting in high costs for the conversion of halogenated hydrocarbons.

In view of this, it is necessary to develop a more efficient and low-energy-consuming method for preparing hydrocarbons from halogenated hydrocarbons.

Contents of the invention

The object of the present invention is to provide a method for preparing alkanes from halogenated hydrocarbons under mild conditions.

Concrete steps of the present invention are:

React halogenated hydrocarbons, metals and initiators, collect liquid phase products, and obtain alkanes after separation.

The metal can be selected from at least one of sodium, iron, silver, zinc and the like.

The initiator can be at least one of simple halogen, halogen and the like.

The molar ratio of the metal to the halogen in the halogenated hydrocarbon may be 1.2-5, preferably 1.5-2.5.

The mass percentage of the initiator may be 0.1%-1.0% of the metal mass.

The reaction temperature is 60-140° C., and the reaction time is 0.5-3 hours.

The separation can be by filtration or distillation.

The beneficial effects of the present invention are as follows:

The reaction of metals and halogenated hydrocarbons in the present invention realizes the conversion of halogenated hydrocarbons, the whole reaction conditions are mild, no precious metal catalyst, hydrogen, high temperature, high pressure, organic matter extraction agent process, etc. are used, and the preparation method of hydrocarbon fuels from non-petrochemical sources is adopted. , the energy consumption of the whole production process is low, the product quality is good, and it has a good application prospect. The preparation process is simple, the operation is convenient, and the efficiency is high, and the prepared hydrocarbon fuel belongs to the category of clean renewable energy and typical "green energy".

Description of drawings

Fig. 1 is the GC-MS total ion chromatogram of 1-iodohexane in embodiment 1.

2 is a GC-MS total ion chromatogram of hydrocarbons after dehalogenation of 1-iodohexane in Example 1.

Fig. 3 is the GC-MS total ion chromatogram of initial substance in embodiment 2.

4 is a GC-MS total ion chromatogram of the product after the dehalogenation of the halogenated hydrocarbon in Example 2.

Detailed ways

The present invention will be specifically described below in conjunction with the examples, and the examples described below are exemplary and do not limit the protection scope of the present invention. The chemical reagents used in the examples of the present invention are all commercially available.

Example 1

Take 10.0g, 5.0g, and 0.01g of 1-iodohexane, zinc powder, and elemental iodine respectively in a round-bottomed flask, magnetically stir at 800rpm, react at 80°C for 0.5h, and collect 3.9g of the oil phase after filtration. The GC-MS charts of 1-iodohexane and the dehalogenated hydrocarbons are shown in Figure 1 and Figure 2, respectively. It can be seen that 1-iodohexane has been completely converted to hexane and a small amount of hexene.

Example 2

The oil phase product produced by the reaction of sorbitol and hydriodic acid is analyzed by gas chromatography mass spectrometry, and the results are shown in Figure 3, the main components are 2-iodohexane, and _C12 and _C18 hydrocarbons. Add 4.0 g of zinc powder to 9.5 g of the oil phase product, the reaction temperature is 60° C., and the reaction time is 1 h. Therefore, the oil phase product contains a small amount of simple iodine, so no additional iodine is needed. Stand still after the reaction, zinc iodide insoluble in hydrocarbons and excess zinc precipitate out, zinc iodide can be used in organic synthesis catalysts, preservatives, electrolytes and analytical reagents, etc. The liquid hydrocarbon quality is 6.8g, and gas chromatography mass spectrometry detection result is as shown in Figure 4, and main component is C ₆ H ₁₄ and C ₁₂ and C ₁₈ hydrocarbons, and this product enters distillation unit 8 and separates further, and vacuum distillation condition is 0.02MPa, 30°C, stop the distillation when there are no more drops from the receiving bottle, the mass of the distilled low-boiling C ₆ H ₁₄ and a very small amount of C ₆ H ₁₂ is 0.3g; the remaining 6.5g of liquid is C ₁₂ and C ₁₈ hydrocarbons, the gas chromatography mass spectrometry detection results are shown in Figure 4. It can be seen that this method not only converts halogenated hydrocarbons into hydrocarbons, but also removes iodine in the oil phase, but does not affect the components of crude oil.

Example 3

Take 12.0g, 5.0g, and 0.005g of 1-iodohexane, magnesium powder, and elemental iodine in a round-bottomed flask. The magnetic stirring speed is 800rpm, and react at 140°C for 1.5h. After filtering, 4.8g of the oil phase is collected, and GC -MS detection results show that 1-iodohexane has been completely converted, 47% of hexane, 4% of hexene and 49% of n-dodecane in the product.

Example 4

Take 12.0g, 4.0g, and 0.02g of 1-iodohexane, magnesium powder, and iodine in a round-bottomed flask, stir at 800rpm, and react at 70°C for 2.0h. After filtration, 4.8g of the oil phase is collected. GC-MS detection results show that 1-iodohexane has been completely converted, and the product contains 46% hexane, 6% hexene and 48% n-dodecane.

Example 5

Take 12.0g, 3.5g, and 0.03g of 1,6-diiodohexane, magnesium powder, and elemental iodine in a round-bottomed flask, stir at 800rpm, react at 80°C for 3h, and collect 3.0g of the oil phase after filtration , GC-MS detection results show that 1,6-diiodohexane has been completely converted, 63% of hexane, 8% of hexene and 29% of n-dodecane in the product.

Example 6

Take 12.0g, 3.0g, and 0.03g of 1,6-diiodohexane, zinc powder, and iodine in a round-bottomed flask, stir at 800rpm, react at 100°C for 1h, and collect 2.9g of the oil phase after filtration , GC-MS detection results show that 1,6-diiodohexane has been completely converted, 95% of hexane and 5% of hexene in the product.

Example 7

Take 12.0g, 3.0g, and 0.02g of 1,6-diiodohexane, zinc powder, and iodine in a round-bottomed flask, stir at 800rpm, react at 110°C for 2h, and collect 3.0g of the oil phase after filtration , GC-MS detection results show that 1,6-diiodohexane has been completely converted, 93% of hexane and 7% of hexene in the product.

Example 8

Take 8.0g, 4.2g, and 0.02g of 1-iodohexane, zinc powder, and elemental iodine in a round-bottomed flask. The magnetic stirring speed is 800rpm, and react at 120°C for 2h. After filtering, 3.2g of the oil phase is collected, and GC- MS detection results show that 1-iodohexane has been completely converted, and the hexane in the liquid product is 100%.

Example 9

Take 11.0g, 10.5g, and 0.06g of 1,6-diiodohexane, zinc powder, and iodine elemental substance in a round-bottomed flask with a magnetic stirring speed of 800rpm, react at 120°C for 2.5h, and collect the oil phase 2.6g after filtration. g, GC-MS detection results show that 1,6-diiodohexane has been completely converted, 92% of hexane and 8% of hexene in the product.

Example 10

Take 6.5g, 4.9g, and 0.03g of 1-iodohexane, zinc powder, and iodine elemental substance in a round-bottomed flask with a magnetic stirring speed of 800rpm, and react at 110°C for 2h. After filtration, 2.6g of the oil phase is collected, and GC- MS detection results show that 1-iodohexane has been completely converted, 95% of hexane and 5% of hexene in the product.

The above descriptions of the embodiments of the present invention enable those skilled in the art to implement or use them, and may be implemented in other embodiments without departing from the principle or scope of the present invention. Accordingly, the invention is not to be limited to the embodiments shown herein, the scope of which is defined by the appended claims and their equivalents.

Claims (8)

1. A method for preparing alkane from halogenated hydrocarbon, characterized in that its concrete steps are: React halogenated hydrocarbons, metals and initiators, collect liquid phase products, and obtain alkanes after separation. 2. A method for preparing alkanes from halogenated hydrocarbons as claimed in claim 1, wherein said metal is selected from at least one of sodium, iron, silver, and zinc. 3. A kind of method for preparing alkane by halogenated hydrocarbon as claimed in claim 1, is characterized in that described initiator adopts at least one in halogen simple substance, halogen. 4. A method for preparing alkanes from halogenated hydrocarbons as claimed in claim 1, characterized in that the molar ratio of the metal to the halogen in the halogenated hydrocarbons is 1.2-5. 5. A method for preparing alkanes from halogenated hydrocarbons as claimed in claim 4, characterized in that the molar ratio of the metal to the halogen in the halogenated hydrocarbons is 1.5 to 2.5. 6. A method for preparing alkanes from halogenated hydrocarbons as claimed in claim 1, characterized in that the mass percentage of the initiator is 0.1% to 1.0% of the metal mass. 7. A method for preparing alkanes from halogenated hydrocarbons as claimed in claim 1, characterized in that the reaction temperature is 60-140° C., and the reaction time is 0.5-3 hours. 8. A method for preparing alkanes from halogenated hydrocarbons as claimed in claim 1, characterized in that said separation is by filtration or distillation separation.