Method for preparing biodiesel by utilizing high-acid value oil

Abstract

The invention relates to a method for preparing biodiesel by utilizing high-acid value oil. The method comprises the following steps of: esterifying the raw materials of the high-acid value oil, enabling glycerol and the raw materials of the high-acid value oil to esterify with each other under the catalyzing action of an ionic liquid, and thus obtaining a mixture of a low-acid value esterification product-monoglyceride, diglyceride or triglyceride; then carrying out interesterification on the esterified oil, namely carrying out interesterification on the mixture of the low-acid value esterification product-monoglyceride, diglyceride or triglyceride and methanol under the action of a base catalyst, and thus generating crud low-acid value biodiesel fatty acid methyl ester; and vacuum distilling and refining the low-acid value biodiesel fatty acid methyl ester so as to obtain the high-purity low-acid value fatty acid methyl ester biodiesel. The details of the method are described in a specification. The method has the advantages that the method does not need post treatment and is shortened in reaction process, lowered in technological energy consumption and clean in process, equipment corrosion caused by conventional sulfuric acid catalyzing is eliminated, the equipment investment and production cost are lowered, and the yield of a target product-biodiesel (fatty acid methyl ester) is high.

Description

technical field

[0001] The present invention relates to a method for producing oil. More specifically, a method for producing biodiesel from high acid value oils and fats. Background technique

[0002] Non-renewable resources such as fossil energy such as oil, coal, and natural gas are gradually being consumed, and renewable energy such as biofuels based on biomass is receiving increasing attention. Among them, biodiesel (a variety of fatty acids) produced from animal and vegetable oils and methanol The mixture of methyl esters) has attracted the attention of countries all over the world.

[0003] At present, there are many biodiesel technologies obtained by transesterification of refined vegetable oil and methanol, such as CN101126031; CN101134904; US7420072; US7112229 and so on. However, China is a populous country, and it is unrealistic to use refined vegetable oil as raw material to produce biodiesel from European and American countries. At the same time, as a country...

Examples

Embodiment 1

[0027] Weigh 100g of oil raw material with an acid value of 40mg KOH / g, of which the fatty acid content is 20g, weigh 13.15g of glycerin, and the molar ratio of glycerol to fatty acid is 2:1; 8% of the raw material weight; with 100g high acid value oil raw material, glycerin 13.15g and 9.1g ionic liquid catalyst alkylimidazole sulfonate (with dry N2 After purging the reactor for 20min, under N2 protection, 1mol of 1- Put methylimidazole into a three-necked flask, add methanesulfonic acid or ethanesulfonic acid while stirring in an equimolar ratio, control the temperature not higher than 40°C, and continue stirring for 1 hour to obtain a light yellow or single brown viscous liquid. Distilled under reduced pressure at 70°C to remove excess water to obtain alkylimidazole sulfonate ionic liquid.) Put it into a 500ml reaction kettle, and perform a vacuum reaction at 120°C and a pressure of 10.0KPa for 3 hours; after the reaction, lower the reaction temperature Stand at room tempera...

Embodiment 2

[0029]Weigh 100g of oil raw material with an acid value of 80mg KOH / g, wherein the fatty acid content is 40g, weigh 52.57g of glycerin, and the molar ratio of glycerol to fatty acid is 4:1; add 22.89g of ionic liquid catalyst alkylimidazole sulfonate, accounting for 15% of the weight of glycerin and high acid value oil raw material; 100g of high acid value oil raw material, 52.57g of glycerin and 22.89g of ionic liquid catalyst are added in a 500ml reactor, and the vacuum reaction is carried out at 130°C and a pressure of 100.0KPa for 3 hours; After the reaction, the reaction temperature was lowered to room temperature and allowed to stand for stratification. The upper layer was esterified oil with low acid value. After detection, the acid value was 0.3 mg KOH / g, and the yield was 108.4 g; the lower layer was non-transglycerin and ionic liquid catalyst. ,recycle.

Embodiment 3

[0031] Weigh 100g of oil raw material with an acid value of 160mg KOH / g, of which the fatty acid content is 80g, weigh 157.72g of glycerin, and the molar ratio of glycerol to fatty acid is 6:1; 30% of the raw material weight; 100g of high acid value oil raw material, 157.72g of glycerin and 77.32g of ionic liquid catalyst alkylimidazole sulfonate were added to a 500ml reactor, and the vacuum reaction was carried out at 140°C and a pressure of 200.0KPa for 3 hours; After the reaction, the reaction temperature was lowered to room temperature and allowed to stand for stratification. The upper layer was esterified oil with low acid value. The acid value after detection was 0.2 mg KOH / g, and the yield was 116.3 g; the lower layer was non-transglycerin and ionic liquid catalyst. ,recycle.

technical field

[0001] The present invention relates to a method for producing oil. More specifically, a method for producing biodiesel from high acid value oils and fats. Background technique

[0002] Non-renewable resources such as fossil energy such as oil, coal, and natural gas are gradually being consumed, and renewable energy such as biofuels based on biomass is receiving increasing attention. Among them, biodiesel (a variety of fatty acids) produced from animal and vegetable oils and methanol The mixture of methyl esters) has attracted the attention of countries all over the world.

[0003] At present, there are many biodiesel technologies obtained by transesterification of refined vegetable oil and methanol, such as CN101126031; CN101134904; US7420072; US7112229 and so on. However, China is a populous country, and it is unrealistic to use refined vegetable oil as raw material to produce biodiesel from European and American countries. At the same time, as a country...

Examples

Embodiment 1

[0027] Weigh 100g of oil raw material with an acid value of 40mg KOH / g, of which the fatty acid content is 20g, weigh 13.15g of glycerin, and the molar ratio of glycerol to fatty acid is 2:1; 8% of the raw material weight; with 100g high acid value oil raw material, glycerin 13.15g and 9.1g ionic liquid catalyst alkylimidazole sulfonate (with dry N2 After purging the reactor for 20min, under N2 protection, 1mol of 1- Put methylimidazole into a three-necked flask, add methanesulfonic acid or ethanesulfonic acid while stirring in an equimolar ratio, control the temperature not higher than 40°C, and continue stirring for 1 hour to obtain a light yellow or single brown viscous liquid. Distilled under reduced pressure at 70°C to remove excess water to obtain alkylimidazole sulfonate ionic liquid.) Put it into a 500ml reaction kettle, and perform a vacuum reaction at 120°C and a pressure of 10.0KPa for 3 hours; after the reaction, lower the reaction temperature Stand at room tempera...

Embodiment 2

[0029]Weigh 100g of oil raw material with an acid value of 80mg KOH / g, wherein the fatty acid content is 40g, weigh 52.57g of glycerin, and the molar ratio of glycerol to fatty acid is 4:1; add 22.89g of ionic liquid catalyst alkylimidazole sulfonate, accounting for 15% of the weight of glycerin and high acid value oil raw material; 100g of high acid value oil raw material, 52.57g of glycerin and 22.89g of ionic liquid catalyst are added in a 500ml reactor, and the vacuum reaction is carried out at 130°C and a pressure of 100.0KPa for 3 hours; After the reaction, the reaction temperature was lowered to room temperature and allowed to stand for stratification. The upper layer was esterified oil with low acid value. After detection, the acid value was 0.3 mg KOH / g, and the yield was 108.4 g; the lower layer was non-transglycerin and ionic liquid catalyst. ,recycle.

Embodiment 3

[0031] Weigh 100g of oil raw material with an acid value of 160mg KOH / g, of which the fatty acid content is 80g, weigh 157.72g of glycerin, and the molar ratio of glycerol to fatty acid is 6:1; 30% of the raw material weight; 100g of high acid value oil raw material, 157.72g of glycerin and 77.32g of ionic liquid catalyst alkylimidazole sulfonate were added to a 500ml reactor, and the vacuum reaction was carried out at 140°C and a pressure of 200.0KPa for 3 hours; After the reaction, the reaction temperature was lowered to room temperature and allowed to stand for stratification. The upper layer was esterified oil with low acid value. The acid value after detection was 0.2 mg KOH / g, and the yield was 116.3 g; the lower layer was non-transglycerin and ionic liquid catalyst. ,recycle.