Esterification method for preparing biodiesel using waste oils and fats

Abstract

Provided is an esterification method for preparing biodiesel using waste oils and fats. Under the normal pressure condition, the mixture of methanesulfonic acid, ethanesulfonic acid or chlorosulfonic acid and erosion restraint agents is used as a catalyst, the using amount of the catalyst is little, the catalyst can be repeatedly used, erosion on equipment is small, through a demister arranged on the top of a reaction kettle, the utilization rate of raw oil and the yield coefficient of coarse methyl ester are improved, heat generated in the reaction process is used for preheating fine methyl alcohol and waste oils and fats, heat is circularly used, energy loss is reduced, methyl alcohol which is not reacted is recovered, and production cost is lowered. The acid value of raw materials of the esterification method is wide (15-180mgKOH / g), the reaction time is short, energy loss is little, production cost is low, the yield coefficient of coarse methyl ester is high, high-acid-value flora and fauna waste oils and fats are esterified in one time to be lower than 1mgKOH / g in acid value, the next transesterification can be directly carried out to prepare biodiesel, and the method is suitable for producing biodiesel in an industrial mode.

Description

technical field

[0001] The invention belongs to the technical field of biodiesel preparation, and in particular relates to an esterification reaction for preparing biodiesel from waste oil. Background technique

[0002] Biodiesel refers to a clean alternative fuel that can be used in compression ignition engines produced from renewable biological resources such as plants and animal fats. In terms of chemical composition, biodiesel is a series of long-chain fatty acid methyl or ethyl esters. It is a high-quality substitute for petrochemical diesel and is known as "green diesel". In recent years, due to the rise of oil prices, the non-renewability of petrochemical energy and a series of environmental problems, biodiesel has become one of the main alternative energy sources for research.

[0003] The preparation of biodiesel is mainly produced by chemical methods, that is, the reaction of animal and vegetable oils with methanol, the esterification reaction occurs under the act...

Examples

Embodiment 1

[0018] Such as figure 1 As shown, add 14 tons of waste oil with an acid value of 120 mgKOH / g after removing impurities and water into the raw oil storage tank 8, and use an oil pump to pump the waste oil into the raw oil heater 6 through the raw oil heat exchanger 7 for heating. Waste oil heated to 100°C is added into the stainless steel reactor 5 through the feed oil inlet at the top of the stainless steel reactor 5, and 52 kg of esterification catalyst is added into the stainless steel reactor 5 through the catalyst inlet at the top of the stainless steel reactor 5. The esterification catalyst is a mixture of methanesulfonic acid and phosphoric acid monoester with a mass ratio of 1:0.1. The refined methanol enters the methanol heater 3 through the methanol heat exchanger 1 to be heated and vaporized. 3 The flow rate of / h flows into the stainless steel reactor 5 from the gas phase methanol pipe 9 in the bottom of the stainless steel reactor 5, and the vaporized methanol flow...

Embodiment 2

[0022] Such as figure 1 As shown, add 14 tons of waste oil with an acid value of 120 mgKOH / g after removing impurities and water into the raw oil storage tank 8, and use an oil pump to pump the waste oil into the raw oil heater 6 through the raw oil heat exchanger 7 for heating. Waste oil heated to 110°C is added to the stainless steel reactor 5 through the feed oil inlet at the top of the stainless steel reactor 5, and 52 kg of esterification catalyst is added to the stainless steel reactor 5 through the catalyst inlet at the top of the stainless steel reactor 5. The esterification catalyst is a mixture of methanesulfonic acid and phosphoric acid monoester with a mass ratio of 1:0.05. The refined methanol enters the methanol heater 3 through the methanol heat exchanger 1 to be heated and vaporized. The vaporized methanol is heated at 0.8m 3 The flow rate of / h flows into the stainless steel reactor 5 from the gas phase methanol pipe 9 in the bottom of the stainless steel reac...

Embodiment 3

[0024] In Example 1, the esterification catalyst used is a mixture of equal mass ethanesulfonic acid and polyether acid phosphate with a mass ratio of 1:0.01, and the other steps are the same as in Example 1 to obtain an acid value of less than 1 mgKOH / g The crude methyl ester, the yield of methyl ester is 95%.

technical field

[0001] The invention belongs to the technical field of biodiesel preparation, and in particular relates to an esterification reaction for preparing biodiesel from waste oil. Background technique

[0002] Biodiesel refers to a clean alternative fuel that can be used in compression ignition engines produced from renewable biological resources such as plants and animal fats. In terms of chemical composition, biodiesel is a series of long-chain fatty acid methyl or ethyl esters. It is a high-quality substitute for petrochemical diesel and is known as "green diesel". In recent years, due to the rise of oil prices, the non-renewability of petrochemical energy and a series of environmental problems, biodiesel has become one of the main alternative energy sources for research.

[0003] The preparation of biodiesel is mainly produced by chemical methods, that is, the reaction of animal and vegetable oils with methanol, the esterification reaction occurs under the act...

Examples

Embodiment 1

[0018] Such as figure 1 As shown, add 14 tons of waste oil with an acid value of 120 mgKOH / g after removing impurities and water into the raw oil storage tank 8, and use an oil pump to pump the waste oil into the raw oil heater 6 through the raw oil heat exchanger 7 for heating. Waste oil heated to 100°C is added into the stainless steel reactor 5 through the feed oil inlet at the top of the stainless steel reactor 5, and 52 kg of esterification catalyst is added into the stainless steel reactor 5 through the catalyst inlet at the top of the stainless steel reactor 5. The esterification catalyst is a mixture of methanesulfonic acid and phosphoric acid monoester with a mass ratio of 1:0.1. The refined methanol enters the methanol heater 3 through the methanol heat exchanger 1 to be heated and vaporized. 3 The flow rate of / h flows into the stainless steel reactor 5 from the gas phase methanol pipe 9 in the bottom of the stainless steel reactor 5, and the vaporized methanol flow...

Embodiment 2

[0022] Such as figure 1 As shown, add 14 tons of waste oil with an acid value of 120 mgKOH / g after removing impurities and water into the raw oil storage tank 8, and use an oil pump to pump the waste oil into the raw oil heater 6 through the raw oil heat exchanger 7 for heating. Waste oil heated to 110°C is added to the stainless steel reactor 5 through the feed oil inlet at the top of the stainless steel reactor 5, and 52 kg of esterification catalyst is added to the stainless steel reactor 5 through the catalyst inlet at the top of the stainless steel reactor 5. The esterification catalyst is a mixture of methanesulfonic acid and phosphoric acid monoester with a mass ratio of 1:0.05. The refined methanol enters the methanol heater 3 through the methanol heat exchanger 1 to be heated and vaporized. The vaporized methanol is heated at 0.8m 3 The flow rate of / h flows into the stainless steel reactor 5 from the gas phase methanol pipe 9 in the bottom of the stainless steel reac...

Embodiment 3

[0024] In Example 1, the esterification catalyst used is a mixture of equal mass ethanesulfonic acid and polyether acid phosphate with a mass ratio of 1:0.01, and the other steps are the same as in Example 1 to obtain an acid value of less than 1 mgKOH / g The crude methyl ester, the yield of methyl ester is 95%.

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