CN103804130A - Method for preparing policosanol through beeswax normal-pressure reduction method - Google Patents

Abstract

The invention provides a method for preparing higher alkanols by reducing beeswax, which is characterized in that beeswax is used as a raw material and the mixture of higher alkanols is prepared by reduction in an open system at normal pressure without the need for an organic solvent to participate in the reaction. Under the condition of 85～120℃ and continuous stirring, react with reducing agent: beeswax=1:10～30 mass ratio; then press beeswax:water:organic solvent=1:10～30:0～30 mass ratio Add water and organic solvent, heat to 45-96°C, add 2M HCl solution according to the mass ratio of beeswax:HCl=1:0.1-0.9, keep warm at 45-96°C for 10-30min; extract the water phase, add water to the organic phase Incubate with hydrochloric acid solution at 45-96°C for 10-30 minutes, adjust the pH value to be neutral; extract the water phase, evaporate the solvent in the organic phase, and the solid after cooling is a mixture of higher alkanols. The invention has the advantages of simple process, easy operation, environmental friendliness and safety, the reaction is carried out in an open system at normal pressure, low cost, high reaction conversion rate, suitable for industrial application and the like.

Description

Method for preparing higher alkanols by beeswax normal pressure reduction method

technical field

The present invention relates to a kind of method that beeswax prepares higher alkanol mixture, especially a kind of method that normal pressure reduction method prepares higher alkanol mixture. the

Background technique

Beeswax is the material secreted by worker bee abdomen, has beeswax, white beeswax, Chinese beeswax etc., beeswax fusing point is 61～65 ℃, acid value 16～23 mg KOH/g, ester value 72～79, saponification value 88-102 mg KOH/g, iodine value 8-11 g/100 g. The main components of beeswax are higher esters formed by fatty acids and long-chain fatty alcohols. Natural higher esters are important raw materials for preparing higher alkanols. the

Higher alkanols, also known as higher fatty alcohols, are chain-like saturated monohydric alcohols containing more than twelve carbon atoms. Higher alkanols widely exist in nature, but hardly exist in the form of natural free fatty alcohols, but in the form of wax esters. The research on higher alkanols at home and abroad focuses on the technical fields of preparation, separation and utilization of C ₂₂ ～C ₃₆ mixed alcohols. Docosanol in the higher alkanol mixture can be used to inhibit prostate tumors; tetracosanol can enhance the function of nerve factors; substance, and has the effects of lowering blood fat and enhancing sexual function; triaicol is a plant growth regulator, which has the effect of promoting plant growth. At present, the methods used to prepare higher alkanols from beeswax are: (1) saponification: wax is saponified and decomposed under alkaline conditions, and after removing fatty acid salts with calcium salt precipitation, solvent extraction is used to obtain a mixture of higher fatty alcohols. The process of this method is long, and the solubility and dispersibility of higher fatty acid esters in the water phase are relatively poor, so the yield is low, and the product purity is not high. Because this method will use a large amount of alkali, not only the operation is complicated , but also cause serious environmental pollution. (2) Transesterification method: alcoholysis of wax, that is, transesterification reaction, and then according to the different boiling points of the reaction products, different products are separated by vacuum distillation to obtain a mixture of higher fatty alcohols. The chemical reaction process of this method is complicated, and there are many types of reaction products obtained, and it is difficult to separate the target product. (3) A method in which the wax is hydrolyzed under acidic conditions, and then the fatty alcohol is leached by a supercritical fluid. In this method, because the acidic hydrolysis of wax is a reversible reaction, its equilibrium point depends on the ratio of water and the nature of ester, and the solubility of wax itself in water is very small, therefore, under acidic conditions, wax is difficult to disperse to water, so the step of hydrolysis is difficult and the yield is low. (4) A method of enzymatically decomposing wax and then extracting fatty alcohol. This method of decomposing wax by lipase or esterase is a promising biological extraction method, which can realize the hydrolysis of higher fatty acid esters under mild conditions, and the biggest advantage of lipase is its selectivity High, which includes position selectivity and fatty acid ester selectivity, so it is an important direction for future development. However, due to the instability of wax-decomposing enzymes, easy poisoning and inactivation, high production costs, and immature process conditions, it is still in the stage of exploratory experiments and has not been applied industrially.

The above several methods all have some deficiencies in the preparation of higher alkanols, but they are all relatively traditional and commonly used methods. The preparation of higher alkanol mixtures by reduction method with beeswax as raw material has not been reported so far. the

Contents of the invention

The object of the present invention is to provide a method for preparing higher alkanol mixtures from beeswax with simple process, easy operation, low cost, mild conditions, environment-friendly and high yield. the

The present invention is accomplished through the following technical solutions: a method for preparing beeswax higher alkanol mixtures by normal pressure reduction, characterized in that through the following steps:

A. Heat the beeswax to 83-120° C., and add the reducing agent to the beeswax at a mass ratio of reducing agent:beeswax=1:10-30 under continuous stirring.

B. According to the mass ratio of beeswax: water: organic solvent = 1: 10 ~ 30: 0 ~ 30, add water and organic solvent to the reaction mixture, heat to 45 ~ 96 ℃, according to beeswax: HCl = 1: 0.1 ~ 0.9 Add 2 M HCl solution to the mass ratio, and keep warm at 45-96 °C for 10-30 min. the

C. Pull out the water phase, add water 15-30 times the mass of beeswax and a small amount of 2 M HCl solution, keep it warm at 45-96 °C for 10-30 min; then use 2 M NaOH solution to adjust the pH value of the solution to neutral. the

D. Take out the water phase, evaporate the solvent in the organic phase to dryness, and cool to normal temperature to obtain block beeswax higher alkanol. the

The reducing agent can be Ranny-Ni, lithium aluminum hydride; the organic solvent is one or more of ether, petroleum ether, methanol, ethanol, chloroform, acetone, ethyl acetate, benzene, butanol and other organic solvents . the

The present invention has the following advantages and effects: adopting the above-mentioned scheme, that is, in a relatively mild normal-pressure open system, a higher alkanol mixture is prepared from beeswax, which is not only simple in process and easy to control, but also without the participation of organic solvents in the reaction process, which is environmentally friendly and safe , low cost, high reaction conversion rate and good product quality. the

Detailed ways

The present invention will be further described below in conjunction with specific embodiments. the

Example 1

A. Heat 100 g of beeswax to 85 °C in a 1000 ml beaker, and slowly add 10 g of reducing agent Ranny-Ni under continuous stirring.

B. Add 300 ml of water to the reaction mixture, heat to 96 °C, add 150 ml of 2 M HCl solution, and keep at 96 °C for 20 min. the

C. Pull out the water phase, add 300 ml of water and 5 ml of 2 M HCl solution, and keep warm at 96°C for 10 min; then use 2 M NaOH solution to adjust the pH value of the solution to neutral. the

D. Take out the water phase and cool to normal temperature to obtain 93 g of beeswax higher alkanol. the

Example 2

A. Heat 1000 g of beeswax to 90 °C in a 20 L flask, and add 80 g of lithium aluminum hydride to the beeswax under continuous stirring.

B. Add 5 L of water and 2 L of chloroform into the flask, heat to 50 °C, add 4 L of 2 M HCl solution, and connect the flask to a condenser at 50 °C for 30 min. the

C. Pull out the water phase, add 5 L of beeswax water and 100 ml of 2 M HCl solution, and keep warm at 50 °C for 10 min; then adjust the pH value of the solution to neutral with 2 M NaOH solution. the

D. Take out the water phase, evaporate the organic solvent in the organic phase to dryness, and cool to normal temperature to obtain 940 g of beeswax higher alkanol. the

Example 3

A. Heat 15 kg of beeswax to 85 °C in a 100 L reactor, and slowly add 1.5 kg of lithium aluminum hydride under continuous stirring.

B. Add 35 L of water, 20 L of petroleum ether, and 5 L of butanol into the reactor, heat to 55 °C, add 10 L of 2 M HCl solution, and keep at 55 °C for 30 min. the

C. Pull out the water phase, add 30 L of water and 100 ml of 2 M HCl solution, keep warm at 80 °C for 30 min; then adjust the pH value of the solution to neutral with 2 M NaOH solution. the

D. Take out the water phase, evaporate the organic solvent in the organic phase to dryness, and cool to normal temperature to obtain 14.1 kg of block beeswax higher alkanol. the

Claims (4)

1. a kind of method that beeswax reduction method prepares higher alkanol, described higher alkanol refers to the chain aliphatic alcohol containing more than 12 carbon atoms, it is characterized in that taking beeswax as raw material, through the following steps: A, beeswax is heated to 83～120 ℃, under the condition of continuous stirring, according to the mass ratio of reducing agent: beeswax=1:10～30, add reducing agent in the beeswax; B. According to the mass ratio of beeswax: water: organic solvent = 1: 10 ~ 30: 0 ~ 30, add water and organic solvent to the reaction mixture, heat to 45 ~ 96 ℃, according to beeswax: HCl = 1: 0.1 ~ 0.9 Add 2 M HCl solution to the mass ratio, and keep warm at 45-96 °C for 10-30 min; C. Pull out the water phase, add water 15-30 times the mass of beeswax and a small amount of 2 M HCl solution, keep warm at 45-96 °C for 10-30 min; then adjust the pH value of the solution to neutral with 2 M NaOH solution; D. Take out the water phase, evaporate the solvent in the organic phase to dryness, and cool to normal temperature to obtain block beeswax higher alkanol. 2. beeswax reduction method according to claim 1 prepares the method for higher alkanol, and described reducing agent is reducing agents such as Ranny-Ni, lithium aluminum hydride. 3. the method for preparing higher alkanols by beeswax reduction method according to claim 1, the water described in step B is tap water, drinking water, distilled water. 4. the method for preparing higher alkanols by beeswax reduction method according to claim 1, the organic solvent described in step B is organic solvents such as ether, sherwood oil, methyl alcohol, ethanol, chloroform, acetone, ethyl acetate, benzene, butanol one or more of them.