Ethanol recovery and heat utilization method

Abstract

The invention relates to an ethanol recovery and heat utilization method. A purpose of the invention is mainly to solve the problems of difficult ethanol recovery, difficult 1,4-dioxane wastewater treatment and high separation energy consumption in the prior art. According to the method, a mixed solution containing water, ethanol and 1,4-dioxane enters from the middle lower portion of an extraction tower, an extraction agent stream enters from the middle upper portion of the extraction tower, a crude ethanol stream is obtained at the top of the extraction tower, and a crude extraction agent stream is obtained at the extraction tower kettle; the crude ethanol stream enters an ethanol recovery tower, an absolute ethanol stream is obtained at the top of the tower, and a 1,4-dioxane stream isobtained at the tower kettle; and the crude extraction agent stream containing the extraction agent and the water enters a solvent recovery tower, the extraction agent stream obtained from the tower kettle returns to the extraction tower, and the tower top gas phase stream is used as part or all of the heat source of the tower kettle reboiler of the ethanol recovery tower. With the technical scheme of the invention, the problems in the prior art are well solved. The method of the invention can be applied to ethanol recovery process production.

Description

technical field

[0001] The invention relates to a method for recovering ethanol, specifically, a process for recovering ethanol from a 1,4-dioxane solvent. Background technique

[0002] Ethanol is commonly known as alcohol, molecular formula C2H6O, according to GB / T394.1-2008 industrial alcohol national standard, excellent grade ≥ 96% vol, first grade ≥ 95% vol; according to GB / T678-2002 absolute ethanol national standard, chemical purity ≥ 99.5% wt , water content ≤ 0.5%wt; analytical pure ≥ 99.7%wt, water content ≤ 0.3%wt; superior pure ≥ 99.8%wt, water content ≤ 0.2%wt; ethanol has a wide range of uses, ethanol can be used to manufacture acetic acid, beverages, Flavors, dyes, fuels, etc. Ethanol with a volume fraction of 70% to 75% is also commonly used as a disinfectant in medical treatment, and it is widely used in national defense chemical industry, medical and health care, food industry, and industrial and agricultural production.

[0003] In recent years, due to fl...

Examples

Embodiment 1

[0050] Dimethyl sulfoxide is used as the extractant, the flow rate of the extractant is 1500kg / h, the feed of the mixed solution is 1000kg / h, the feed composition of the mixed solution is ethanol 43%wt, 1,4-dioxane 5%wt, water 52%wt , the solvent ratio is 0.6, according to figure 1 process shown.

[0051] The theoretical plate number of the extraction column is 40, the operating pressure is 0.22MPaA, and the temperature at the top of the column is 100°C.

[0052] The theoretical plate number of the ethanol recovery tower is 70, the operating pressure is 0.20MPaA, the temperature at the top of the tower is 98°C, and the temperature at the bottom of the tower is 119°C.

[0053] The number of theoretical plates of the solvent recovery tower is 30, the operating pressure is 0.26MPaA, and the temperature at the top of the tower is 129°C.

[0054] The temperature of the vapor phase stream at the top of the solvent recovery tower is 10°C higher than the temperature of the 1,4-dioxa...

Embodiment 2

[0058] Dimethyl sulfoxide is used as the extractant, the flow rate of the extractant is 1500kg / h, the feed of the mixed solution is 1000kg / h, the feed composition of the mixed solution is ethanol 43%wt, 1,4-dioxane 5%wt, water 52%wt , the solvent ratio is 0.6, according to figure 1 process shown.

[0059] The theoretical plate number of the extraction column is 50, the operating pressure is 0.40MPaA, and the temperature at the top of the column is 118°C.

[0060] The theoretical plate number of the ethanol recovery tower is 70, the operating pressure is 0.33MPaA, the temperature at the top of the tower is 112°C, and the temperature at the bottom of the tower is 136°C.

[0061] The number of theoretical plates of the solvent recovery tower is 40, the operating pressure is 0.43MPaA, and the temperature at the top of the tower is 146°C.

[0062] The temperature of the vapor phase stream at the top of the solvent recovery tower is 10°C higher than the temperature of the 1,4-diox...

Embodiment 3

[0066] Dimethyl sulfoxide is used as the extractant, the flow rate of the extractant is 1500kg / h, the feed of the mixed solution is 1000kg / h, the feed composition of the mixed solution is ethanol 43%wt, 1,4-dioxane 5%wt, water 52%wt , the solvent ratio is 0.6, according to figure 1 process shown.

[0067] The theoretical plate number of the extraction column is 60, the operating pressure is 0.60MPaA, and the temperature at the top of the column is 118°C.

[0068] The theoretical plate number of the ethanol recovery tower is 70, the operating pressure is 0.53MPaA, the temperature at the top of the tower is 117°C, and the temperature at the bottom of the tower is 139°C.

[0069] The number of theoretical plates of the solvent recovery tower is 50, the operating pressure is 0.62MPaA, and the temperature at the top of the tower is 159°C.

[0070] The temperature of the vapor phase stream at the top of the solvent recovery tower is 20°C higher than the temperature of the 1,4-diox...

technical field

[0001] The invention relates to a method for recovering ethanol, specifically, a process for recovering ethanol from a 1,4-dioxane solvent. Background technique

[0002] Ethanol is commonly known as alcohol, molecular formula C2H6O, according to GB / T394.1-2008 industrial alcohol national standard, excellent grade ≥ 96% vol, first grade ≥ 95% vol; according to GB / T678-2002 absolute ethanol national standard, chemical purity ≥ 99.5% wt , water content ≤ 0.5%wt; analytical pure ≥ 99.7%wt, water content ≤ 0.3%wt; superior pure ≥ 99.8%wt, water content ≤ 0.2%wt; ethanol has a wide range of uses, ethanol can be used to manufacture acetic acid, beverages, Flavors, dyes, fuels, etc. Ethanol with a volume fraction of 70% to 75% is also commonly used as a disinfectant in medical treatment, and it is widely used in national defense chemical industry, medical and health care, food industry, and industrial and agricultural production.

[0003] In recent years, due to fl...

Examples

Embodiment 1

[0050] Dimethyl sulfoxide is used as the extractant, the flow rate of the extractant is 1500kg / h, the feed of the mixed solution is 1000kg / h, the feed composition of the mixed solution is ethanol 43%wt, 1,4-dioxane 5%wt, water 52%wt , the solvent ratio is 0.6, according to figure 1 process shown.

[0051] The theoretical plate number of the extraction column is 40, the operating pressure is 0.22MPaA, and the temperature at the top of the column is 100°C.

[0052] The theoretical plate number of the ethanol recovery tower is 70, the operating pressure is 0.20MPaA, the temperature at the top of the tower is 98°C, and the temperature at the bottom of the tower is 119°C.

[0053] The number of theoretical plates of the solvent recovery tower is 30, the operating pressure is 0.26MPaA, and the temperature at the top of the tower is 129°C.

[0054] The temperature of the vapor phase stream at the top of the solvent recovery tower is 10°C higher than the temperature of the 1,4-dioxa...

Embodiment 2

[0058] Dimethyl sulfoxide is used as the extractant, the flow rate of the extractant is 1500kg / h, the feed of the mixed solution is 1000kg / h, the feed composition of the mixed solution is ethanol 43%wt, 1,4-dioxane 5%wt, water 52%wt , the solvent ratio is 0.6, according to figure 1 process shown.

[0059] The theoretical plate number of the extraction column is 50, the operating pressure is 0.40MPaA, and the temperature at the top of the column is 118°C.

[0060] The theoretical plate number of the ethanol recovery tower is 70, the operating pressure is 0.33MPaA, the temperature at the top of the tower is 112°C, and the temperature at the bottom of the tower is 136°C.

[0061] The number of theoretical plates of the solvent recovery tower is 40, the operating pressure is 0.43MPaA, and the temperature at the top of the tower is 146°C.

[0062] The temperature of the vapor phase stream at the top of the solvent recovery tower is 10°C higher than the temperature of the 1,4-diox...

Embodiment 3

[0066] Dimethyl sulfoxide is used as the extractant, the flow rate of the extractant is 1500kg / h, the feed of the mixed solution is 1000kg / h, the feed composition of the mixed solution is ethanol 43%wt, 1,4-dioxane 5%wt, water 52%wt , the solvent ratio is 0.6, according to figure 1 process shown.

[0067] The theoretical plate number of the extraction column is 60, the operating pressure is 0.60MPaA, and the temperature at the top of the column is 118°C.

[0068] The theoretical plate number of the ethanol recovery tower is 70, the operating pressure is 0.53MPaA, the temperature at the top of the tower is 117°C, and the temperature at the bottom of the tower is 139°C.

[0069] The number of theoretical plates of the solvent recovery tower is 50, the operating pressure is 0.62MPaA, and the temperature at the top of the tower is 159°C.

[0070] The temperature of the vapor phase stream at the top of the solvent recovery tower is 20°C higher than the temperature of the 1,4-diox...

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