Ethanol purification method using extraction CT

Abstract

A method and system for the purification of food-grade ethanol using extractive distillation with propylene glycol as the extraction solvent are provided herein. The system and process comprises one or more separators and distillation columns and optionally provides a propylene glycol recirculation flow.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 495,317, filed on April 11, 2023, the entire content of which is incorporated herein by reference.

Background Art

[0002] The separation of impurities from ethanol suitable for use in the beverage industry presents a unique set of challenges due to the need for very high - purity products and the need to remove all potentially toxic by - products from the manufacturing process. Extractive distillation provides an effective method for producing high - purity ethanol; however, the current solvents used in such processes are not suitable for food - grade applications due to their toxicity. Such purification processes are made more difficult due to the formation of azeotropic mixtures when purifying ethanol in the presence of water and other alcohols. An improved method for purifying ethanol is needed.

Summary of the Invention

[0003] A method for purifying food-grade ethanol is provided herein. The method includes (1) combining an alcohol feedstock containing ethanol and propanol with a propylene glycol feedstock containing propylene glycol to produce a purified feedstock; (2) distilling the purified feedstock at extraction distillation temperature and pressure to produce an ethanol product mixture containing ethanol and a propylene glycol mixture containing propylene glycol and propanol; and (3) separating propylene glycol from propanol in the propylene glycol mixture at separation temperature and pressure to produce a propanol product mixture containing propanol and a propylene glycol product mixture containing propylene glycol. The method may also include combining the propylene glycol product mixture with a propylene glycol feedstock. The method may also include distilling a crude alcohol feedstock containing methanol, ethanol, and propanol at crude alcohol distillation temperature and pressure to produce an alcohol feedstock and a methanol product mixture containing methanol. This method may include separating a hydrated alcohol feedstock containing water, methanol, ethanol, and propanol at a hydrated alcohol separation temperature and hydrated alcohol separation pressure to produce a crude alcohol feedstock and a wastewater mixture containing water.

[0004] A system for the purification of food-grade ethanol is also provided herein. This system may include an alcohol feedstock; a propylene glycol feedstock; and an extraction separator including an alcohol feedstock inlet, a propylene glycol feedstock inlet, an ethanol outlet, and a propylene glycol mixture outlet. The alcohol feedstock may be connected to the alcohol feedstock inlet, and the propylene glycol feedstock may be connected to the propylene glycol feedstock inlet. The propylene glycol separator may include a propylene glycol mixture inlet, a propanol outlet, and a propylene glycol outlet. The propylene glycol mixture inlet may be connected to the propylene glycol mixture outlet from the extraction separator.

[0005] The propylene glycol outlet from the propylene glycol separator may be connected to the propylene glycol feedstock. The system may include a methanol separator including a crude alcohol feedstock and / or a crude alcohol feedstock inlet, a methanol outlet, and an alcohol feedstock outlet. The crude alcohol feedstock may be connected to the crude alcohol feedstock inlet, and the alcohol feedstock outlet may be connected to the alcohol feedstock. The system may include a hydrated alcohol feedstock and, optionally, a water separator including a hydrated alcohol feedstock inlet, a water outlet, and a crude alcohol feedstock outlet. The hydrated alcohol feedstock may be connected to the hydrated alcohol feedstock inlet, and the crude alcohol feedstock outlet may be connected to the crude alcohol feedstock. [Brief explanation of the drawing]

[0006] [Figure 1] Figure 1 is an example of a schematic process diagram for the purification of food-grade ethanol from a hydrated alcohol feedstock using several separators and extractive distillation.

[0007] [Figure 2] Figure 2 is an example of a schematic process diagram for the extraction distillation of propanol impurities from an alcohol feedstock using extraction distillation with propylene glycol as the extraction solvent. [Modes for carrying out the invention]

[0008] A method and system for purifying food-grade ethanol using extractive distillation with propylene glycol as the extraction solvent are provided herein.

[0009] Method of extraction and distillation

[0010] A method for purifying food-grade ethanol is disclosed herein. The method comprises: combining (a) an alcohol feedstock containing ethanol and propanol and (b) a propylene glycol feedstock containing propylene glycol to produce a purified feedstock; distilling the purified feedstock at extraction distillation temperature and pressure to produce (a) an ethanol product mixture containing ethanol and (b) a propylene glycol mixture containing propylene glycol and propanol; and separating propylene glycol from propanol in the propylene glycol mixture at separation temperature and pressure to produce (a) a propanol product mixture containing propanol and (b) a propylene glycol product mixture containing propylene glycol.

[0011] The alcohol supply raw material may contain ethanol exceeding approximately 85% (v / v), 90% (v / v), 93% (v / v), 95% (v / v), or 98% (v / v). The alcohol supply raw material may contain ethanol between approximately 85% (v / v) and less than approximately 100% (v / v). The alcohol supply raw material may contain ethanol between approximately 90% (v / v) and less than approximately 100% (v / v). The alcohol supply raw material may contain ethanol between approximately 88% (v / v) and approximately 99% (v / v). The alcohol supply raw material may contain ethanol between approximately 90% (v / v) and approximately 99% (v / v). The alcohol supply raw material may contain ethanol between approximately 92% (v / v) and approximately 99% (v / v). The alcohol supply raw material may contain approximately 95% (v / v) to approximately 99% (v / v) ethanol. The alcohol supply raw material may contain approximately 90% (v / v), approximately 92% (v / v), approximately 95% (v / v), approximately 97% (v / v), approximately 98% (v / v), or approximately 99% (v / v) ethanol.

[0012] The molar ratio of alcohol feedstock to propylene glycol feedstock in the refined feedstock may be about 1:0.5 to about 1:6, or about 1:1 to about 1:3. The molar ratio of alcohol feedstock to propylene glycol feedstock may be about 1:0.75. The molar ratio of alcohol feedstock to propylene glycol feedstock may be about 1:1. The molar ratio of alcohol feedstock to propylene glycol feedstock may be about 1:2. The molar ratio of alcohol feedstock to propylene glycol feedstock may be about 1:3. The molar ratio of alcohol feedstock to propylene glycol feedstock may be about 1:4. The molar ratio of alcohol feedstock to propylene glycol feedstock may be about 1:5. In certain embodiments, these ratios represent the ratio of ethanol + propanol in the alcohol feedstock to propylene glycol in the propylene glycol feedstock.

[0013] Propanol may include i-propanol and / or n-propanol. Alcohol supply material may contain less than about 20% (v / v), less than about 15% (v / v), less than about 12% (v / v), less than about 10% (v / v), or less than about 9% (v / v) of propanol. Alcohol supply material may contain propanol from about 1% (v / v) to about 20% (v / v), propanol from about 5% (v / v) to about 20% (v / v), propanol from about 5% (v / v) to about 15% (v / v), propanol from about 5% (v / v) to about 12% (v / v), or propanol from about 8% (v / v) to about 10% (v / v). Propanol may include i-propanol, n-propanol, or a combination of both i-propanol and n-propanol.

[0014] Alcohol-supplying raw materials may contain less than approximately 15% (v / v) of n-propanol. Alcohol-supplying raw materials may contain less than approximately 10% (v / v) of n-propanol. Alcohol-supplying raw materials may contain less than approximately 5% (v / v) of n-propanol. Alcohol-supplying raw materials may contain less than approximately 1% (v / v) of n-propanol. Alcohol-supplying raw materials may contain approximately 0.1% (v / v) to approximately 15% (v / v) of n-propanol, approximately 1% (v / v) to approximately 10% (v / v) of n-propanol, or approximately 5% (v / v) to approximately 10% (v / v) of n-propanol. Alcohol-supplying raw materials may contain approximately 10% (v / v) of n-propanol. Alcohol-supplying raw materials may contain approximately 5% (v / v) of n-propanol. The alcohol supply raw material may contain approximately 1% (v / v) n-propanol.

[0015] Alcohol-supplying raw materials may contain less than approximately 15% (v / v) i-propanol. Alcohol-supplying raw materials may contain less than approximately 10% (v / v) i-propanol. Alcohol-supplying raw materials may contain less than approximately 5% (v / v) i-propanol. Alcohol-supplying raw materials may contain less than approximately 1% (v / v) i-propanol. Alcohol-supplying raw materials may contain approximately 0.1% (v / v) to approximately 15% (v / v) i-propanol, approximately 0.5% (v / v) to approximately 10% (v / v) i-propanol, or approximately 0.1% (v / v) to approximately 5% (v / v) i-propanol. Alcohol-supplying raw materials may contain approximately 10% (v / v) i-propanol. Alcohol-supplying raw materials may contain approximately 5% (v / v) i-propanol. The alcohol-supplying raw material may contain approximately 1% (v / v) i-propanol.

[0016] The alcohol supply raw material may contain ethanol exceeding 80% (v / v), i-propanol less than approximately 15% (v / v), and n-propanol less than approximately 15% (v / v). The alcohol supply raw material may contain ethanol exceeding 80% (v / v), i-propanol less than approximately 10% (v / v), and n-propanol less than approximately 10% (v / v). The alcohol supply raw material may contain ethanol exceeding 85% (v / v), i-propanol less than approximately 5% (v / v), and n-propanol less than approximately 15% (v / v). The alcohol supply raw material may contain ethanol exceeding 90% (v / v), i-propanol less than approximately 1% (v / v), and n-propanol less than approximately 10% (v / v).

[0017] The alcohol supply material may contain additional impurities such as methanol.

[0018] The extraction distillation temperature may be approximately 50°C to 200°C, and the extraction distillation pressure may be approximately 0 psia to 20 psia. The extraction distillation temperature may be approximately 50°C to 150°C. The extraction distillation temperature may be approximately 80°C to 120°C. The extraction distillation temperature may be approximately 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 140°C, or 150°C.

[0019] The extraction distillation pressure can range from approximately 0 psia to approximately 15 psia. The extraction distillation pressure can range from approximately 5 psia to approximately 10 psia. The extraction distillation pressure can range from approximately 0 psia. The extraction distillation pressure can range from approximately 1 psia. The extraction distillation pressure can range from approximately 2 psia. The extraction distillation pressure can range from approximately 3 psia. The extraction distillation pressure can range from approximately 4 psia. The extraction distillation pressure can range from approximately 5 psia. The extraction distillation pressure can range from approximately 6 psia. The extraction distillation pressure can range from approximately 7 psia. The extraction distillation pressure can range from approximately 8 psia. The extraction distillation pressure can range from approximately 9 psia. The extraction distillation pressure can range from approximately 10 psia. The extraction distillation pressure can range from approximately 11 psia. The extraction distillation pressure can range from approximately 12 psia. The extraction distillation pressure can range from approximately 13 psia. The extraction distillation pressure can range from approximately 14 psia. The extraction distillation pressure can range from approximately 15 psia.

[0020] The extraction distillation pressure can range from approximately 0 psig to approximately 20 psig. The extraction distillation pressure can range from approximately 0 psig to approximately 15 psig. The extraction distillation pressure can range from approximately 0 psig. The extraction distillation pressure can range from approximately 1 psig. The extraction distillation pressure can range from approximately 2 psig. The extraction distillation pressure can range from approximately 3 psig. The extraction distillation pressure can range from approximately 4 psig. The extraction distillation pressure can range from approximately 5 psig. The extraction distillation pressure can range from approximately 9 psig. The extraction distillation pressure can range from approximately 6 psig. The extraction distillation pressure can range from approximately 7 psig. The extraction distillation pressure can range from approximately 8 psig. The extraction distillation pressure can range from approximately 9 psig. The extraction distillation pressure can range from approximately 10 psig. The extraction distillation pressure can range from approximately 11 psig. The extraction distillation pressure can range from approximately 12 psig. The extraction distillation pressure can range from approximately 13 psig. The extraction distillation pressure can range from approximately 14 psig. The extraction distillation pressure can be approximately 15 psig.

[0021] The ethanol product mixture may contain ethanol exceeding approximately 90% (v / v), 91% (v / v), 92% (v / v), 93% (v / v), 94% (v / v), 95% (v / v), 96% (v / v), 97% (v / v), 98% (v / v), or 99% (v / v). The ethanol product mixture may contain food-grade ethanol.

[0022] The ethanol product mixture may contain approximately 80% (v / v) to approximately 100% (v / v) ethanol. The ethanol product mixture may contain approximately 85% (v / v) to approximately 100% (v / v) ethanol. The ethanol product mixture may contain approximately 90% (v / v) to approximately 100% (v / v) ethanol. The ethanol product mixture may contain approximately 91% (v / v) to approximately 100% (v / v) ethanol. The ethanol product mixture may contain approximately 92% (v / v) to approximately 100% (v / v) ethanol. The ethanol product mixture may contain approximately 93% (v / v) to approximately 100% (v / v) ethanol. The ethanol product mixture may contain approximately 94% (v / v) to approximately 100% (v / v) ethanol. The ethanol product mixture may contain approximately 95% (v / v) to approximately 100% (v / v) ethanol. The ethanol product mixture may contain approximately 96% (v / v) to approximately 100% (v / v) ethanol. The ethanol product mixture may contain approximately 97% (v / v) to approximately 100% (v / v) ethanol. The ethanol product mixture may contain approximately 98% (v / v) to approximately 100% (v / v) ethanol. The ethanol product mixture may contain approximately 99% (v / v) to approximately 100% (v / v) ethanol.

[0023] The ethanol product mixture may contain approximately 90% (v / v) ethanol. The ethanol product mixture may contain approximately 91% (v / v) ethanol. The ethanol product mixture may contain approximately 92% (v / v) ethanol. The ethanol product mixture may contain approximately 93% (v / v) ethanol. The ethanol product mixture may contain approximately 94% (v / v) ethanol. The ethanol product mixture may contain approximately 95% (v / v) ethanol. The ethanol product mixture may contain approximately 96% (v / v) ethanol. The ethanol product mixture may contain approximately 97% (v / v) ethanol. The ethanol product mixture may contain approximately 98% (v / v) ethanol. The ethanol product mixture may contain approximately 99% (v / v) ethanol.

[0024] In certain embodiments, the ethanol product mixture consists essentially of ethanol. In further embodiments, the ethanol product mixture consists of ethanol.

[0025] In certain embodiments, the ethanol product mixture contains propanol. The ethanol product mixture can contain less than about 15% (v / v) propanol. The ethanol product mixture can contain less than about 10% (v / v) propanol. The ethanol product mixture can contain less than about 5% (v / v) propanol. The ethanol product mixture can contain less than about 4% (v / v) propanol. The ethanol product mixture can contain less than about 3% (v / v) propanol. The ethanol product mixture can contain less than about 2% (v / v) propanol. The ethanol product mixture can contain less than about 1% (v / v) propanol. The ethanol product mixture can contain less than about 0.5% (v / v) propanol. The ethanol product mixture can contain from about 0.01% (v / v) to about 15% (v / v) propanol. The ethanol product mixture can contain from about 0.01% (v / v) to about 10% (v / v) propanol. The ethanol product mixture can contain from about 0.01% (v / v) to about 5% (v / v) propanol. The ethanol product mixture can contain from about 0.01% (v / v) to about 1% (v / v) propanol. The ethanol product mixture can contain about 10% (v / v) propanol, about 5% (v / v) propanol, about 4% (v / v) propanol, about 3% (v / v) propanol, about 2% (v / v) propanol, about 1% (v / v) propanol, or about 0.5% (v / v) propanol. In still further embodiments, the ethanol product mixture is essentially free of propanol.

[0026] In certain embodiments, the mass fraction of propanol to ethanol in the ethanol product mixture is more than 70% lower than the mass fraction of ethanol to propanol in the alcohol feedstock. The mass fraction of propanol to ethanol in the ethanol product mixture may be more than 75% lower than the mass fraction of ethanol to propanol in the alcohol feedstock. The mass fraction of propanol to ethanol in the ethanol product mixture may be more than 80% lower than the mass fraction of ethanol to propanol in the alcohol feedstock. The mass fraction of propanol to ethanol in the ethanol product mixture may be more than 85% lower than the mass fraction of ethanol to propanol in the alcohol feedstock. The mass fraction of propanol to ethanol in the ethanol product mixture may be more than 90% lower than the mass fraction of ethanol to propanol in the alcohol feedstock. The mass fraction of propanol to ethanol in the ethanol product mixture may be more than 91% lower than the mass fraction of ethanol to propanol in the alcohol feedstock. The mass fraction of propanol to ethanol in the ethanol product mixture may be more than approximately 92% lower than the mass fraction of ethanol to propanol in the alcohol supply material. The mass fraction of propanol to ethanol in the ethanol product mixture may be more than approximately 93% lower than the mass fraction of ethanol to propanol in the alcohol supply material. The mass fraction of propanol to ethanol in the ethanol product mixture may be more than approximately 94% lower than the mass fraction of ethanol to propanol in the alcohol supply material. The mass fraction of propanol to ethanol in the ethanol product mixture may be more than approximately 95% lower than the mass fraction of ethanol to propanol in the alcohol supply material. The mass fraction of propanol to ethanol in the ethanol product mixture may be more than approximately 96% lower than the mass fraction of ethanol to propanol in the alcohol supply material. The mass fraction of propanol to ethanol in the ethanol product mixture may be more than approximately 97% lower than the mass fraction of ethanol to propanol in the alcohol supply material.The mass fraction of propanol to ethanol in the ethanol product mixture may be as much as about 98% lower than the mass fraction of ethanol to propanol in the alcohol feedstock. The mass fraction of propanol to ethanol in the ethanol product mixture may be as much as about 99% lower than the mass fraction of ethanol to propanol in the alcohol feedstock.

[0027] In a further embodiment, the mass fraction of propanol to ethanol in the ethanol product mixture is about 70%, about 75%, about 80%, about 85%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% lower than the mass fraction of ethanol to propanol in the alcohol feedstock.

[0028] The alcohol feedstock may contain methanol. The alcohol feedstock may contain less than about 0.1% (v / v) methanol. The alcohol feedstock may contain less than about 0.01% (v / v) methanol. The alcohol feedstock may contain less than about 0.005% (v / v) methanol. The alcohol feedstock may contain less than about 0.001% (v / v) methanol. The alcohol feedstock may contain about 0.1% (v / v) methanol. The alcohol feedstock may contain about 0.01% (v / v) methanol. The alcohol feedstock may contain about 0.005% (v / v) methanol. The alcohol feedstock may contain about 0.001% (v / v) methanol.

[0029] A propylene glycol mixture may contain more than approximately 80% (v / v) propylene glycol. A propylene glycol mixture may contain more than approximately 85% (v / v) propylene glycol. A propylene glycol mixture may contain more than approximately 90% (v / v) propylene glycol. A propylene glycol mixture may contain more than approximately 91% (v / v) propylene glycol. A propylene glycol mixture may contain more than approximately 92% (v / v) propylene glycol. A propylene glycol mixture may contain more than approximately 93% (v / v) propylene glycol. A propylene glycol mixture may contain more than approximately 94% (v / v) propylene glycol. A propylene glycol mixture may contain more than approximately 95% (v / v) propylene glycol. A propylene glycol mixture may contain more than approximately 96% (v / v) propylene glycol. A propylene glycol mixture may contain more than approximately 97% (v / v) propylene glycol. A propylene glycol mixture may contain more than approximately 98% (v / v) propylene glycol. A propylene glycol mixture may contain more than approximately 99% (v / v) propylene glycol.

[0030] A propylene glycol mixture may contain approximately 80% (v / v) to approximately 100% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 85% (v / v) to approximately 100% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 90% (v / v) to approximately 100% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 91% (v / v) to approximately 100% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 92% (v / v) to approximately 100% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 93% (v / v) to approximately 100% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 94% (v / v) to approximately 100% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 95% (v / v) to approximately 100% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 96% (v / v) to approximately 100% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 97% (v / v) to approximately 100% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 98% (v / v) to approximately 100% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 99% (v / v) to approximately 100% (v / v) propylene glycol.

[0031] A propylene glycol mixture may contain approximately 80% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 85% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 90% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 91% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 92% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 93% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 94% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 95% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 96% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 97% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 98% (v / v) propylene glycol. A propylene glycol mixture may contain approximately 99% (v / v) propylene glycol.

[0032] In certain embodiments, the propylene glycol mixture may further contain ethanol. The propylene glycol mixture may contain less than about 15% (v / v) of ethanol. The propylene glycol mixture may contain less than about 10% (v / v) of ethanol. The propylene glycol mixture may contain less than about 5% (v / v) of ethanol. The propylene glycol mixture may contain less than about 4% (v / v) of ethanol. The propylene glycol mixture may contain less than about 3% (v / v) of ethanol. The propylene glycol mixture may contain less than about 2% (v / v) of ethanol. The propylene glycol mixture may contain less than about 1% (v / v) of ethanol. The propylene glycol mixture may contain about 15% (v / v) of ethanol. The propylene glycol mixture may contain about 10% (v / v) of ethanol. The propylene glycol mixture may contain about 5% (v / v) of ethanol. The propylene glycol mixture may contain about 4% (v / v) of ethanol. A propylene glycol mixture may contain approximately 3% (v / v) ethanol. A propylene glycol mixture may contain approximately 2% (v / v) ethanol. A propylene glycol mixture may contain approximately 1% (v / v) ethanol.

[0033] In certain embodiments, the propylene glycol product mixture may contain more than about 80% (v / v) propylene glycol. The propylene glycol product mixture may contain more than about 85% (v / v) propylene glycol. The propylene glycol product mixture may contain more than about 90% (v / v) propylene glycol. The propylene glycol product mixture may contain more than about 91% (v / v) propylene glycol. The propylene glycol product mixture may contain more than about 92% (v / v) propylene glycol. The propylene glycol product mixture may contain more than about 93% (v / v) propylene glycol. The propylene glycol product mixture may contain more than about 94% (v / v) propylene glycol. The propylene glycol product mixture may contain more than about 95% (v / v) propylene glycol. The propylene glycol product mixture may contain more than about 96% (v / v) propylene glycol. A propylene glycol product mixture may contain more than approximately 97% (v / v) propylene glycol. A propylene glycol product mixture may contain more than approximately 98% (v / v) propylene glycol. A propylene glycol product mixture may contain more than approximately 99% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 80% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 85% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 90% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 91% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 92% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 93% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 94% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 95% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 96% (v / v) propylene glycol.A propylene glycol product mixture may contain approximately 97% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 98% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 99% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 80% (v / v) to approximately 100% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 85% (v / v) to approximately 100% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 90% (v / v) to approximately 100% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 91% (v / v) to approximately 100% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 92% (v / v) to approximately 100% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 93% (v / v) to approximately 100% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 94% (v / v) to approximately 100% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 95% (v / v) to approximately 100% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 96% (v / v) to approximately 100% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 97% (v / v) to approximately 100% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 98% (v / v) propylene glycol to approximately 100% (v / v) propylene glycol. A propylene glycol product mixture may contain approximately 99% (v / v) propylene glycol to approximately 100% (v / v) propylene glycol. A propylene glycol product mixture may essentially consist of propylene glycol. A propylene glycol product mixture may consist of propylene glycol.

[0034] In certain embodiments, the propylene glycol product mixture contains propanol. The propylene glycol product mixture may contain less than about 15% (v / v) of propanol, less than about 10% (v / v) of propanol, less than about 5% (v / v) of propanol, less than about 4% (v / v) of propanol, less than about 3% (v / v) of propanol, less than about 2% (v / v) of propanol, or less than about 1% (v / v) of propanol. The propylene glycol product mixture may contain about 15% (v / v) of propanol. The propylene glycol product mixture may contain about 10% (v / v) of propanol. The propylene glycol product mixture may contain about 5% (v / v) of propanol. The propylene glycol product mixture may contain about 4% (v / v) of propanol. The propylene glycol product mixture may contain about 3% (v / v) of propanol. A propylene glycol product mixture may contain about 2% (v / v) of propanol. A propylene glycol product mixture may contain about 1% (v / v) of propanol. A propylene glycol product mixture may contain less than about 1% (v / v) of propanol, less than about 0.5% (v / v) of propanol, less than about 0.2% (v / v) of propanol, less than about 0.1% (v / v) of propanol, or less than about 0.05% (v / v) of propanol. A propylene glycol product mixture may not contain propanol in nature.

[0035] The propylene glycol product mixture may contain more than 80% propylene glycol and less than about 15% (v / v) propanol.

[0036] In certain embodiments, the propanol product mixture may contain more than about 60% (v / v) propanol. The propanol product mixture may contain more than about 65% (v / v) propanol. The propanol product mixture may contain more than about 70% (v / v) propanol. The propanol product mixture may contain more than about 75% (v / v) propanol. The propanol product mixture may contain more than about 80% (v / v) propanol. The propanol product mixture may contain more than about 85% (v / v) propanol. The propanol product mixture may contain more than about 90% (v / v) propanol. The propanol product mixture may contain more than about 91% (v / v) propanol. The propanol product mixture may contain more than about 92% (v / v) propanol. The propanol product mixture may contain more than about 93% (v / v) propanol. The propanol product mixture may contain more than approximately 94% (v / v) propanol. The propanol product mixture may contain more than approximately 95% (v / v) propanol. The propanol product mixture may contain more than approximately 96% (v / v) propanol. The propanol product mixture may contain more than approximately 97% (v / v) propanol. The propanol product mixture may contain more than approximately 98% (v / v) propanol. The propanol product mixture may contain more than approximately 99% (v / v) propanol. The propanol product mixture may contain approximately 60% (v / v) propanol. The propanol product mixture may contain approximately 65% ​​(v / v) propanol. The propanol product mixture may contain approximately 70% (v / v) propanol. The propanol product mixture may contain approximately 75% (v / v) propanol. The propanol product mixture may contain approximately 80% (v / v) propanol. The propanol product mixture may contain approximately 85% (v / v) propanol. The propanol product mixture may contain approximately 90% (v / v) propanol. The propanol product mixture may contain approximately 91% (v / v) propanol. The propanol product mixture may contain approximately 92% (v / v) propanol. The propanol product mixture may contain approximately 93% (v / v) propanol.The propanol product mixture may contain approximately 94% (v / v) propanol. The propanol product mixture may contain approximately 95% (v / v) propanol. The propanol product mixture may contain approximately 96% (v / v) propanol. The propanol product mixture may contain approximately 97% (v / v) propanol. The propanol product mixture may contain approximately 98% (v / v) propanol. The propanol product mixture may contain approximately 99% (v / v) propanol. The propanol product mixture may contain approximately 60% (v / v) to approximately 100% (v / v) propanol. The propanol product mixture may contain approximately 65% ​​(v / v) to approximately 100% (v / v) propanol. The propanol product mixture may contain approximately 70% (v / v) propanol to approximately 100% (v / v) propanol. The propanol product mixture may contain approximately 75% (v / v) propanol to approximately 100% (v / v) propanol. The propanol product mixture may contain approximately 80% (v / v) propanol to approximately 100% (v / v) propanol. The propanol product mixture may contain approximately 85% (v / v) propanol to approximately 100% (v / v) propanol. The propanol product mixture may contain approximately 90% (v / v) propanol to approximately 100% (v / v) propanol. The propanol product mixture may contain approximately 91% (v / v) propanol to approximately 100% (v / v) propanol. The propanol product mixture may contain approximately 92% (v / v) propanol to approximately 100% (v / v) propanol. The propanol product mixture may contain approximately 93% (v / v) propanol to approximately 100% (v / v) propanol. The propanol product mixture may contain approximately 94% (v / v) propanol to approximately 100% (v / v) propanol. The propanol product mixture may contain approximately 95% (v / v) propanol to approximately 100% (v / v) propanol. The propanol product mixture may contain approximately 96% (v / v) propanol to approximately 100% (v / v) propanol. The propanol product mixture may contain approximately 97% (v / v) propanol to approximately 100% (v / v) propanol.The propanol product mixture may contain about 98% (v / v) propanol to about 100% (v / v) propanol. The propanol product mixture may contain about 99% (v / v) propanol to about 100% (v / v) propanol. In certain embodiments, the propanol product mixture is essentially propanol. In further embodiments, the propanol product mixture consists of propanol.

[0037] In certain embodiments, the propanol product mixture further comprises propylene glycol. The propanol product mixture may contain less than about 15% (v / v) propylene glycol, less than about 10% (v / v) propylene glycol, less than about 5% (v / v) propylene glycol, less than about 4% (v / v) propylene glycol, less than about 3% (v / v) propylene glycol, less than about 2% (v / v) propylene glycol, or less than about 1% (v / v) propylene glycol. The propanol product mixture may contain about 15% (v / v) propylene glycol. The propanol product mixture may contain about 10% (v / v) propylene glycol. The propanol product mixture may contain about 5% (v / v) propylene glycol. The propanol product mixture may contain about 4% (v / v) propylene glycol. The propanol product mixture may contain about 3% (v / v) propylene glycol. The propanol product mixture may contain about 2% (v / v) propylene glycol. The propanol product mixture may contain about 1% (v / v) propylene glycol. In further embodiments, the propanol product mixture may not contain a substantial amount of propylene glycol, for example, less than about 1% (v / v) propylene glycol, less than about 0.5% (v / v) propylene glycol, or less than about 0.2% (v / v) propylene glycol.

[0038] The propanol product mixture may further contain ethanol. The propanol product mixture may contain less than about 50% (v / v) of ethanol. The propanol product mixture may contain less than about 45% (v / v) of ethanol. The propanol product mixture may contain less than about 40% (v / v) of ethanol. The propanol product mixture may contain less than about 35% (v / v) of ethanol. The propanol product mixture may contain less than about 30% (v / v) of ethanol. The propanol product mixture may contain less than about 25% (v / v) of ethanol. The propanol product mixture may contain less than about 20% (v / v) of ethanol. The propanol product mixture may contain less than about 15% (v / v) of ethanol. The propanol product mixture may contain less than about 10% (v / v) of ethanol. The propanol product mixture may contain less than about 5% (v / v) of ethanol. The propanol product mixture may contain less than about 4% (v / v) of ethanol. The propanol product mixture may contain less than approximately 3% (v / v) of ethanol. The propanol product mixture may contain less than approximately 2% (v / v) of ethanol. The propanol product mixture may contain less than approximately 1% (v / v) of ethanol. The propanol product mixture may contain approximately 50% (v / v) of ethanol. The propanol product mixture may contain approximately 45% (v / v) of ethanol. The propanol product mixture may contain approximately 40% (v / v) of ethanol. The propanol product mixture may contain approximately 35% (v / v) of ethanol. The propanol product mixture may contain approximately 30% (v / v) of ethanol. The propanol product mixture may contain approximately 25% (v / v) of ethanol. The propanol product mixture may contain approximately 20% (v / v) of ethanol. The propanol product mixture may contain approximately 15% (v / v) of ethanol. The propanol product mixture may contain approximately 10% (v / v) ethanol. The propanol product mixture may contain approximately 5% (v / v) ethanol. The propanol product mixture may contain approximately 4% (v / v) ethanol. The propanol product mixture may contain approximately 3% (v / v) ethanol. The propanol product mixture may contain approximately 2% (v / v) ethanol.The propanol product mixture may contain approximately 1% (v / v) ethanol.

[0039] In one embodiment, the propanol product mixture may contain more than 60% (v / v) propanol, less than 40% (v / v) ethanol, and less than about 10% (v / v) propylene glycol. The propanol product mixture may contain more than 70% (v / v) propanol, less than 30% (v / v) ethanol, and less than about 5% (v / v) propylene glycol. The propanol product mixture may contain more than 80% (v / v) propanol, less than 20% (v / v) ethanol, and less than about 5% (v / v) propylene glycol.

[0040] The step of separating propylene glycol from propanol in a propylene glycol mixture may be carried out using a propylene glycol separator, which can be any distillation column known for use in the art in this manner. The separation may be carried out at separation temperature and separation pressure.

[0041] The separation temperature can be approximately 50°C to 220°C, and the separation can be approximately 0 psia to 15 psia. The separation temperature can be approximately 60°C to 210°C. The separation temperature can be approximately 80°C to 200°C. The separation temperature can be approximately 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, or 210°C.

[0042] The separation pressure can be approximately 0 psia to 15 psia. The separation pressure can be approximately 5 psia to 10 psia. The separation pressure can be approximately 8 psia to 12 psia. The separation pressure can be approximately 0 psia. The separation pressure can be approximately 1 psia. The separation pressure can be approximately 2 psia. The separation pressure can be approximately 3 psia. The separation pressure can be approximately 4 psia. The separation pressure can be approximately 5 psia. The separation pressure can be approximately 6 psia. The separation pressure can be approximately 7 psia. The separation pressure can be approximately 8 psia. The separation pressure can be approximately 9 psia. The separation pressure can be approximately 10 psia. The separation pressure can be approximately 11 psia. The separation pressure can be approximately 12 psia. The separation pressure can be approximately 13 psia. The separation pressure can be approximately 14 psia. The separation pressure can be approximately 15 psia.

[0043] In certain embodiments, all or part of the propylene glycol product mixture is combined with a propylene glycol feedstock such that the propylene glycol product mixture is a recirculating flow. In certain embodiments, the propylene glycol product mixture is the propylene glycol feedstock such that a separate flow of the propylene glycol feedstock is not required to meet the system's needs.

[0044] The methods disclosed herein may further include the step of distilling a crude alcohol feedstock containing methanol, ethanol, and propanol at a crude alcohol distillation temperature and crude alcohol distillation pressure to produce a methanol product mixture containing methanol and the alcohol feedstock.

[0045] The crude alcohol distillation temperature can be approximately 60°C to 150°C, and the crude alcohol distillation pressure can be approximately 0 psia to 20 psia. The crude alcohol distillation temperature can be approximately 60°C to 100°C. The crude alcohol distillation temperature can be approximately 60°C. The crude alcohol distillation temperature can be approximately 70°C. The crude alcohol distillation temperature can be approximately 80°C. The crude alcohol distillation temperature can be approximately 90°C. The crude alcohol distillation temperature can be approximately 100°C.

[0046] The crude alcohol distillation pressure can be approximately 0 psia to 15 psia, approximately 0 psia to 10 psia, or approximately 5 psia to 15 psia. The crude alcohol distillation pressure can be approximately 0 psia. The crude alcohol distillation pressure can be approximately 1 psia. The crude alcohol distillation pressure can be approximately 2 psia. The crude alcohol distillation pressure can be approximately 3 psia. The crude alcohol distillation pressure can be approximately 4 psia. The crude alcohol distillation pressure can be approximately 5 psia. The crude alcohol distillation pressure can be approximately 6 psia. The crude alcohol distillation pressure can be approximately 7 psia. The crude alcohol distillation pressure can be approximately 8 psia. The crude alcohol distillation pressure can be approximately 9 psia. The crude alcohol distillation pressure can be approximately 10 psia. The crude alcohol distillation pressure can be approximately 11 psia. The crude alcohol distillation pressure can be approximately 12 psia. The crude alcohol distillation pressure can be approximately 13 psia. The crude alcohol distillation pressure can be approximately 14 psia. The crude alcohol distillation pressure can be approximately 15 psia.

[0047] The crude alcohol distillation pressure can range from approximately 0 psig to approximately 20 psig. The crude alcohol distillation pressure can range from approximately 0 psig to approximately 15 psig. The crude alcohol distillation pressure can range from approximately 0 psig. The crude alcohol distillation pressure can range from approximately 1 psig. The crude alcohol distillation pressure can range from approximately 2 psig. The crude alcohol distillation pressure can range from approximately 3 psig. The crude alcohol distillation pressure can range from approximately 4 psig. The crude alcohol distillation pressure can range from approximately 5 psig. The crude alcohol distillation pressure can range from approximately 9 psig. The crude alcohol distillation pressure can range from approximately 6 psig. The crude alcohol distillation pressure can range from approximately 7 psig. The crude alcohol distillation pressure can range from approximately 8 psig. The crude alcohol distillation pressure can range from approximately 9 psig. The crude alcohol distillation pressure can range from approximately 10 psig. The crude alcohol distillation pressure can range from approximately 11 psig. The crude alcohol distillation pressure can range from approximately 12 psig. The crude alcohol distillation pressure can range from approximately 13 psig. The crude alcohol distillation pressure can be approximately 14 psig. The crude alcohol distillation pressure can be approximately 15 psig.

[0048] In certain embodiments, the mass fraction of methanol to ethanol in the alcohol supply material is more than 25% lower than the mass fraction of methanol to ethanol in the crude alcohol supply material. The mass fraction of methanol to ethanol in the alcohol supply material may be more than 30% lower than the mass fraction of methanol to ethanol in the crude alcohol supply material. The mass fraction of methanol to ethanol in the alcohol supply material may be more than 35% lower than the mass fraction of methanol to ethanol in the crude alcohol supply material. The mass fraction of methanol to ethanol in the alcohol supply material may be more than 36% lower than the mass fraction of methanol to ethanol in the crude alcohol supply material. The mass fraction of methanol to ethanol in the alcohol supply material may be more than 40% lower than the mass fraction of methanol to ethanol in the crude alcohol supply material. The mass fraction of methanol to ethanol in the alcohol supply material may be more than 45% lower than the mass fraction of methanol to ethanol in the crude alcohol supply material. The mass fraction of methanol to ethanol in the alcohol supply material may be more than 50% lower than the mass fraction of methanol to ethanol in the crude alcohol supply material. The mass fraction of methanol to ethanol in the alcohol supply material may be more than approximately 55% lower than the mass fraction of methanol to ethanol in the crude alcohol supply material. The mass fraction of methanol to ethanol in the alcohol supply material may be more than approximately 60% lower than the mass fraction of methanol to ethanol in the crude alcohol supply material. The mass fraction of methanol to ethanol in the alcohol supply material may be more than approximately 65% ​​lower than the mass fraction of methanol to ethanol in the crude alcohol supply material. The mass fraction of methanol to ethanol in the alcohol supply material may be more than approximately 70% lower than the mass fraction of methanol to ethanol in the crude alcohol supply material. The mass fraction of methanol to ethanol in the alcohol supply material may be more than approximately 75% lower than the mass fraction of methanol to ethanol in the crude alcohol supply material.The mass fraction of methanol to ethanol in the alcohol supply raw material may be approximately 80% lower than the mass fraction of methanol to ethanol in the crude alcohol supply raw material.

[0049] The mass fraction of methanol to ethanol in the alcohol supply raw material may be about 25%, 30%, 35%, 36%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80% lower than the mass fraction of methanol to ethanol in the crude alcohol supply raw material.

[0050] In certain embodiments, the methanol product mixture is essentially free of ethanol. In further embodiments, the methanol product mixture is essentially free of ethanol or propanol.

[0051] In certain embodiments, the methanol product mixture consists essentially of methanol. In further embodiments, the methanol product mixture consists of methanol.

[0052] The methods disclosed herein may further include the step of separating a hydrated alcohol feedstock containing water, methanol, ethanol, and propanol at a hydrated alcohol separation temperature and a hydrated alcohol separation pressure to produce a wastewater mixture containing water and a crude alcohol feedstock.

[0053] The hydration alcohol separation temperature can be approximately 50°C to 200°C. The hydration alcohol separation temperature can be approximately 50°C to 150°C. The hydration alcohol separation temperature can be approximately 50°C. The hydration alcohol separation temperature can be approximately 60°C. The hydration alcohol separation temperature can be approximately 70°C. The hydration alcohol separation temperature can be approximately 80°C. The hydration alcohol separation temperature can be approximately 90°C. The hydration alcohol separation temperature can be approximately 100°C. The hydration alcohol separation temperature can be approximately 110°C. The hydration alcohol separation temperature can be approximately 120°C. The hydration alcohol separation temperature can be approximately 130°C. The hydration alcohol separation temperature can be approximately 140°C. The hydration alcohol separation temperature can be approximately 150°C.

[0054] The hydration alcohol separation pressure can be approximately 0 psia to approximately 20 psia. The hydration alcohol separation pressure can be approximately 0 psia to approximately 15 psia, approximately 10 psia to approximately 15 psia, or approximately 0 psia to approximately 5 psia. The hydration alcohol separation pressure can be approximately 0 psia. The hydration alcohol separation pressure can be approximately 1 psia. The hydration alcohol separation pressure can be approximately 2 psia. The hydration alcohol separation pressure can be approximately 3 psia. The hydration alcohol separation pressure can be approximately 4 psia. The hydration alcohol separation pressure can be approximately 5 psia. The hydration alcohol separation pressure can be approximately 6 psia. The hydration alcohol separation pressure can be approximately 7 psia. The hydration alcohol separation pressure can be approximately 8 psia. The hydration alcohol separation pressure can be approximately 9 psia. The hydration alcohol separation pressure can be approximately 10 psia. The hydration alcohol separation pressure can be approximately 11 psia. The hydration alcohol separation pressure can be approximately 12 psia. The hydration alcohol separation pressure can be approximately 13 psia. The hydration alcohol separation pressure can be approximately 14 psia. The hydration alcohol separation pressure can be approximately 15 psia.

[0055] The hydration alcohol separation pressure can be approximately 0 psig to approximately 20 psig. The hydration alcohol separation pressure can be approximately 0 psig to approximately 15 psig. The hydration alcohol separation pressure can be approximately 0 psig. The hydration alcohol separation pressure can be approximately 1 psig. The hydration alcohol separation pressure can be approximately 2 psig. The hydration alcohol separation pressure can be approximately 3 psig. The hydration alcohol separation pressure can be approximately 4 psig. The hydration alcohol separation pressure can be approximately 5 psig. The hydration alcohol separation pressure can be approximately 9 psig. The hydration alcohol separation pressure can be approximately 6 psig. The hydration alcohol separation pressure can be approximately 7 psig. The hydration alcohol separation pressure can be approximately 8 psig. The hydration alcohol separation pressure can be approximately 9 psig. The hydration alcohol separation pressure can be approximately 10 psig. The hydration alcohol separation pressure can be approximately 11 psig. The hydration alcohol separation pressure can be approximately 12 psig. The hydration alcohol separation pressure can be approximately 13 psig. The hydration alcohol separation pressure can be approximately 14 psig. The hydration alcohol separation pressure can be approximately 15 psig.

[0056] In certain embodiments, the hydrated alcohol supply material may contain more than about 50% (v / v) water. The hydrated alcohol supply material may contain more than about 60% (v / v) water. The hydrated alcohol supply material may contain more than about 70% (v / v) water. The hydrated alcohol supply material may contain more than about 80% (v / v) water. The hydrated alcohol supply material may contain more than about 90% (v / v) water. The hydrated alcohol supply material may contain more than about 95% (v / v) water. The hydrated alcohol supply material may contain more than about 99% (v / v) water. The hydrated alcohol supply material may contain about 50% (v / v) water. The hydrated alcohol supply material may contain about 60% (v / v) water. The hydrated alcohol supply material may contain about 70% (v / v) water. The hydrated alcohol supply material may contain about 80% (v / v) water. The raw material for hydration alcohol may contain approximately 90% (v / v) water. The raw material for hydration alcohol may contain approximately 95% (v / v) water. The raw material for hydration alcohol may contain approximately 99% (v / v) water. The raw material for hydration alcohol may contain approximately 50% (v / v) to approximately 100% (v / v) water. The raw material for hydration alcohol may contain approximately 60% (v / v) to less than approximately 100% (v / v) water. The raw material for hydration alcohol may contain approximately 70% (v / v) to approximately 99% (v / v) water. The raw material for hydration alcohol may contain approximately 70% (v / v) to approximately 90% (v / v) water. The raw material for hydration alcohol may contain approximately 70% (v / v) to approximately 85% (v / v) water. The raw material for supplying hydrated alcohol may contain approximately 80% (v / v) water to approximately 99% (v / v) water.

[0057] In certain embodiments, the hydration alcohol feedstock may contain less than about 50% (v / v) methanol. The hydration alcohol feedstock may contain less than about 45% (v / v) methanol. The hydration alcohol feedstock may contain less than about 40% (v / v) methanol. The hydration alcohol feedstock may contain less than about 35% (v / v) methanol. The hydration alcohol feedstock may contain less than about 30% (v / v) methanol. The hydration alcohol feedstock may contain about 10% (v / v) to about 50% (v / v) methanol, about 15% (v / v) to about 45% (v / v) methanol, about 20% (v / v) to about 40% (v / v) methanol, about 20% (v / v) to about 35% (v / v) methanol, or about 25% (v / v) to about 30% (v / v) methanol. The hydrated alcohol supply material may contain approximately 50% (v / v) methanol. The hydrated alcohol supply material may contain approximately 45% (v / v) methanol. The hydrated alcohol supply material may contain approximately 40% (v / v) methanol. The hydrated alcohol supply material may contain approximately 35% (v / v) methanol. The hydrated alcohol supply material may contain approximately 30% (v / v) methanol.

[0058] In certain embodiments, the hydrated alcohol supplying material includes ethanol less than about 40% (v / v), less than about 35% (v / v), less than about 30% (v / v), less than about 25% (v / v), less than about 20% (v / v), less than about 15% (v / v), less than about 10% (v / v), less than about 5% (v / v), or less than about 1% (v / v). The hydrated alcohol supplying material may include ethanol from about 0.1% (v / v) to about 30% (v / v), ethanol from about 0.1% (v / v) to about 20% (v / v), ethanol from about 0.1% (v / v) to about 10% (v / v), ethanol from about 0.1% (v / v) to about 5% (v / v), or ethanol from about 0.1% (v / v) to about 1% (v / v). The hydrated alcohol supply raw material may contain approximately 1% (v / v) ethanol. The hydrated alcohol supply raw material may contain approximately 0.5% (v / v) ethanol. The hydrated alcohol supply raw material may contain approximately 0.3% (v / v) ethanol.

[0059] The hydrated alcohol supply material may contain more than approximately 50% (v / v) of water, less than approximately 50% (v / v) of methanol, and less than approximately 20% (v / v) of ethanol. The hydrated alcohol supply material may contain more than approximately 60% (v / v) of water, less than approximately 40% (v / v) of methanol, and less than approximately 20% (v / v) of ethanol. The hydrated alcohol supply material may contain more than approximately 70% (v / v) of water, less than approximately 30% (v / v) of methanol, and less than approximately 5% (v / v) of ethanol. The hydrated alcohol supply material may contain approximately 60% (v / v) to less than approximately 100% (v / v) of water, approximately 10% (v / v) to approximately 50% (v / v) of methanol, and approximately 0.1% (v / v) to approximately 30% (v / v) of ethanol.

[0060] In certain embodiments, the hydration alcohol feedstock contains propanol and / or butanol. The hydration alcohol feedstock may contain less than about 15% (v / v) of propanol, less than about 10% (v / v) of propanol, less than about 5% (v / v) of propanol, or less than about 2% (v / v) of propanol. The hydration alcohol feedstock may contain about 10% (v / v) to about 0.1% (v / v) of propanol, about 5% (v / v) to about 0.1% (v / v) of propanol, about 3% (v / v) to about 0.1% (v / v) of propanol, or about 1% (v / v) to about 0.1% (v / v) of propanol. The hydrated alcohol supply material may contain less than approximately 10% (v / v) butanol, less than approximately 5% (v / v) butanol, less than approximately 2% (v / v) butanol, or less than approximately 1% (v / v) butanol. The hydrated alcohol supply material may contain approximately 10% (v / v) to approximately 0.1% (v / v) butanol, approximately 5% (v / v) to approximately 0.1% (v / v) butanol, approximately 3% (v / v) to approximately 0.1% (v / v) butanol, or approximately 1% (v / v) to approximately 0.1% (v / v) butanol.

[0061] In certain embodiments, the crude alcohol feedstock further contains water. The mass fraction of water relative to methanol / ethanol / propanol in the crude alcohol feedstock may be more than 70% lower than the mass fraction of water relative to methanol / ethanol / propanol in the hydrated alcohol feedstock. The mass fraction of water relative to methanol / ethanol / propanol in the crude alcohol feedstock may be more than 75% lower than the mass fraction of water relative to methanol / ethanol / propanol in the hydrated alcohol feedstock. The mass fraction of water relative to methanol / ethanol / propanol in the crude alcohol feedstock may be more than 80% lower than the mass fraction of water relative to methanol / ethanol / propanol in the hydrated alcohol feedstock. The mass fraction of water relative to methanol / ethanol / propanol in the crude alcohol feedstock may be more than 85% lower than the mass fraction of water relative to methanol / ethanol / propanol in the hydrated alcohol feedstock. The mass fraction of water relative to methanol / ethanol / propanol in the crude alcohol feedstock may be more than 90% lower than the mass fraction of water relative to methanol / ethanol / propanol in the hydrated alcohol feedstock. The mass fraction of water relative to methanol / ethanol / propanol in the crude alcohol feedstock may be about 70% lower than the mass fraction of water relative to methanol / ethanol / propanol in the hydrated alcohol feedstock. The mass fraction of water relative to methanol / ethanol / propanol in the crude alcohol feedstock may be about 75% lower than the mass fraction of water relative to methanol / ethanol / propanol in the hydrated alcohol feedstock. The mass fraction of water relative to methanol / ethanol / propanol in the crude alcohol feedstock may be about 80% lower than the mass fraction of water relative to methanol / ethanol / propanol in the hydrated alcohol feedstock. The mass fraction of water relative to methanol / ethanol / propanol in the crude alcohol feedstock may be about 85% lower than the mass fraction of water relative to methanol / ethanol / propanol in the hydrated alcohol feedstock.The mass fraction of water relative to methanol / ethanol / propanol in the crude alcohol feedstock may be approximately 90% lower than the mass fraction of water relative to methanol / ethanol / propanol in the hydrated alcohol feedstock.

[0062] Crude alcohol supply raw materials may contain less than approximately 70% (v / v) water. Crude alcohol supply raw materials may contain less than approximately 60% (v / v) water. Crude alcohol supply raw materials may contain less than approximately 50% (v / v) water. Crude alcohol supply raw materials may contain less than approximately 40% (v / v) water. Crude alcohol supply raw materials may contain less than approximately 30% (v / v) water. Crude alcohol supply raw materials may contain less than approximately 20% (v / v) water. Crude alcohol supply raw materials may contain less than approximately 10% (v / v) water. Crude alcohol supply raw materials may contain less than approximately 5% (v / v) water. The raw material for the crude alcohol supply may contain approximately 0.5% (v / v) to approximately 70% (v / v) of water, approximately 1% (v / v) to approximately 60% (v / v) of water, approximately 1% (v / v) to approximately 50% (v / v) of water, approximately 1% (v / v) to approximately 40% (v / v) of water, approximately 1% (v / v) to approximately 30% (v / v) of water, approximately 1% (v / v) to approximately 20% (v / v) of water, approximately 1% (v / v) to approximately 10% (v / v) of water, or approximately 1% (v / v) to approximately 5% (v / v) of water. The raw material for the crude alcohol supply may contain approximately 60% (v / v) water, approximately 50% (v / v) water, approximately 40% (v / v) water, approximately 30% (v / v) water, approximately 20% (v / v) water, approximately 10% (v / v) water, or approximately 5% (v / v) water.

[0063] In a particular embodiment, the crude alcohol feedstock contains methanol exceeding approximately 40% (v / v), methanol exceeding approximately 50% (v / v), methanol exceeding approximately 60% (v / v), methanol exceeding approximately 70% (v / v), methanol exceeding approximately 80% (v / v), methanol exceeding approximately 90% (v / v), or methanol exceeding approximately 95% (v / v). The crude alcohol supply raw material may contain methanol of approximately 45% (v / v) to approximately 99% (v / v), approximately 55% (v / v) to approximately 99% (v / v), approximately 60% (v / v) to approximately 99% (v / v), approximately 65% ​​(v / v) to approximately 98% (v / v), approximately 70% (v / v) to approximately 99% (v / v), approximately 75% (v / v) to approximately 99% (v / v), approximately 80% (v / v) to approximately 99% (v / v), approximately 85% (v / v) to approximately 99% (v / v), approximately 90% (v / v) to approximately 99% (v / v), or approximately 91% (v / v) to approximately 99% (v / v).

[0064] In certain embodiments, the crude alcohol feedstock includes ethanol less than about 40% (v / v), less than about 35% (v / v), less than about 30% (v / v), less than about 25% (v / v), less than about 20% (v / v), less than about 15% (v / v), less than about 10% (v / v), less than about 5% (v / v), or less than about 2% (v / v). The crude alcohol feedstock may include ethanol from about 0.1% (v / v) to about 30% (v / v), ethanol from about 0.1% (v / v) to about 20% (v / v), ethanol from about 0.1% (v / v) to about 10% (v / v), ethanol from about 0.1% (v / v) to about 5% (v / v), or ethanol from about 0.5% (v / v) to about 2% (v / v). The crude alcohol supply raw material may contain approximately 5% (v / v) ethanol. The crude alcohol supply raw material may contain approximately 0.5% (v / v) ethanol. The crude alcohol supply raw material may contain approximately 1% (v / v) ethanol.

[0065] Crude alcohol supply raw materials may contain approximately 0.5% (v / v) to approximately 70% (v / v) water, approximately 45% (v / v) to approximately 99% (v / v) methanol, and approximately 0.1% (v / v) to approximately 30% (v / v) ethanol. Crude alcohol supply raw materials may contain approximately 1% (v / v) to approximately 60% (v / v) water, approximately 55% (v / v) to approximately 99% (v / v) methanol, and approximately 0.1% (v / v) to approximately 20% (v / v) ethanol. Crude alcohol supply raw materials may contain approximately 1% (v / v) to approximately 50% (v / v) water, approximately 65% ​​(v / v) to approximately 99% (v / v) methanol, and approximately 0.1% (v / v) to approximately 10% (v / v) ethanol. Crude alcohol feedstock may contain approximately 1% (v / v) to 40% (v / v) water, approximately 75% (v / v) to 99% (v / v) methanol, and approximately 0.1% (v / v) to 5% (v / v) ethanol. Crude alcohol feedstock may contain approximately 1% (v / v) to 30% (v / v) water and approximately 0.5% (v / v) to 2% (v / v) ethanol.

[0066] In certain embodiments, the crude alcohol feedstock further comprises propanol and / or butanol. The crude alcohol feedstock may contain less than about 15% (v / v) of propanol, less than about 10% (v / v) of propanol, less than about 5% (v / v) of propanol, less than about 2% (v / v) of propanol, or less than about 1% (v / v) of propanol. The crude alcohol feedstock may contain about 0.1% (v / v) to about 10% (v / v) of propanol, about 0.1% (v / v) to about 5% (v / v) of propanol, about 0.1% (v / v) to about 3% (v / v) of propanol, or about 0.1% (v / v) to about 1% (v / v) of propanol. Crude alcohol feedstock may contain less than approximately 10% (v / v) butanol, less than approximately 5% (v / v) butanol, less than approximately 2% (v / v) butanol, or less than approximately 1% (v / v) butanol. Crude alcohol feedstock may contain approximately 0.1% (v / v) to approximately 10% (v / v) butanol, approximately 0.1% (v / v) to approximately 5% (v / v) butanol, approximately 0.1% (v / v) to approximately 3% (v / v) butanol, or approximately 0.1% (v / v) to approximately 1% (v / v) butanol.

[0067] In certain embodiments, the crude alcohol feedstock contains pentanol. The crude alcohol feedstock may contain less than about 5% (v / v) of pentanol, less than about 2% (v / v) of pentanol, or less than about 1% (v / v) of pentanol. The crude alcohol feedstock may contain about 0.1% (v / v) to about 3% (v / v) of pentanol, about 0.1% (v / v) to about 2% (v / v) of pentanol, about 0.1% (v / v) to about 1% (v / v) of propanol, or about 0.1% (v / v) to about 0.5% (v / v) of pentanol. The crude alcohol feedstock may contain about 0.1% (v / v) of pentanol.

[0068] The wastewater mixture may contain more than approximately 90% (v / v) water. The wastewater mixture may contain more than approximately 91% (v / v) water. The wastewater mixture may contain more than approximately 92% (v / v) water. The wastewater mixture may contain more than approximately 93% (v / v) water. The wastewater mixture may contain more than approximately 94% (v / v) water. The wastewater mixture may contain more than approximately 95% (v / v) water. In further embodiments, the wastewater mixture may contain more than approximately 96% (v / v) water. The wastewater mixture may contain more than approximately 97% (v / v) water. The wastewater mixture may contain more than approximately 98% (v / v) water. The wastewater mixture may contain more than approximately 99% (v / v) water. The wastewater mixture may contain approximately 90% (v / v) water, approximately 91% (v / v) water, approximately 92% (v / v) water, approximately 93% (v / v) water, approximately 94% (v / v) water, approximately 95% (v / v) water, approximately 96% (v / v) water, approximately 97% (v / v) water, approximately 98% (v / v) water, or approximately 99% (v / v) water.

[0069] The wastewater mixture may contain approximately 90% (v / v) water to approximately 100% (v / v) water. The wastewater mixture may contain approximately 91% (v / v) water to approximately 100% (v / v) water. The wastewater mixture may contain approximately 92% (v / v) water to approximately 100% (v / v) water. The wastewater mixture may contain approximately 93% (v / v) water to approximately 100% (v / v) water. The wastewater mixture may contain approximately 94% (v / v) water to approximately 100% (v / v) water. The wastewater mixture may contain approximately 95% (v / v) water to approximately 100% (v / v) water. The wastewater mixture may contain approximately 96% (v / v) water to approximately 100% (v / v) water. The wastewater mixture may contain approximately 97% (v / v) water to approximately 100% (v / v) water. The wastewater mixture may contain approximately 98% (v / v) water to approximately 100% (v / v) water. The wastewater mixture may contain approximately 99% (v / v) water to approximately 100% (v / v) water. In a further embodiment, the wastewater mixture is essentially water. In a further embodiment, the wastewater mixture consists of water.

[0070] In certain embodiments, the wastewater mixture contains methanol. The wastewater mixture may contain less than 10% (v / v) methanol. The wastewater mixture may contain less than 9% (v / v) methanol. The wastewater mixture may contain less than 8% (v / v) methanol. The wastewater mixture may contain less than about 7% (v / v) methanol. The wastewater mixture may contain less than about 6% (v / v) methanol. The wastewater mixture may contain less than about 5% (v / v) methanol. The wastewater mixture may contain less than about 4% (v / v) methanol. The wastewater mixture may contain less than about 3% (v / v) methanol. The wastewater mixture may contain less than about 2% (v / v) methanol. The wastewater mixture may contain less than about 1% (v / v) methanol. The wastewater mixture may contain approximately 8% (v / v) methanol, approximately 7% (v / v) methanol, approximately 6% (v / v) methanol, approximately 5% (v / v) methanol, approximately 4% (v / v) methanol, approximately 3% (v / v) methanol, approximately 2% (v / v) methanol, and approximately 1% (v / v) methanol. The wastewater mixture may contain approximately 0.01% (v / v) to approximately 3% (v / v) methanol. The wastewater mixture may contain approximately 0.01% (v / v) to approximately 1% (v / v) methanol. The wastewater mixture may contain approximately 0.05% (v / v) to approximately 0.5% (v / v) methanol.

[0071] In certain embodiments, the wastewater mixture consists of water and methanol. In certain embodiments, the wastewater mixture consists of water and methanol and is essentially free of propanol, ethanol, butanol, and / or pentanol (e.g., less than about 0.01% (v / v), less than about 0.001% (v / v), or about 0.000% (v / v)).

[0072] System for extractive distillation

[0073] A system for the purification of food-grade ethanol is provided herein. The system disclosed herein comprises an alcohol feedstock, a propylene glycol feedstock, an extraction separator, and a propylene glycol separator. The extraction separator may include an alcohol feedstock inlet, a propylene glycol feedstock inlet, an ethanol outlet, and a propylene glycol mixture outlet. The alcohol feedstock may be connected to the alcohol feedstock inlet. The propylene glycol feedstock may be connected to the propylene glycol feedstock inlet. The propylene glycol separator may include a propylene glycol mixture inlet, a propanol outlet, and a propylene glycol outlet. The propylene glycol mixture inlet may be connected to the propylene glycol mixture outlet from the extraction separator.

[0074] In certain embodiments, the extraction separator is a first distillation column. In further embodiments, the first distillation column includes metal packing. In even further embodiments, the metal packing is random metal packing or structured metal packing.

[0075] In certain embodiments, the propylene glycol separator is a second distillation column. In further embodiments, the second distillation column includes metal packing. In even further embodiments, the metal packing is random metal packing or structured metal packing.

[0076] In a particular embodiment, the propylene glycol outlet from the propylene glycol separator is connected to the propylene glycol feedstock.

[0077] This system may further include a crude alcohol feedstock, and a methanol separator including a crude alcohol feedstock inlet, a methanol outlet, and an alcohol feedstock outlet. The crude alcohol feedstock may be connected to the crude alcohol feedstock inlet, and the alcohol feedstock outlet may be connected to the alcohol feedstock.

[0078] In certain embodiments, the methanol separator is a third distillation column. In further embodiments, the third distillation column includes metal packing. In even further embodiments, the metal packing is random metal packing or structured metal packing.

[0079] This system may further include a water separator comprising a hydrated alcohol feedstock, a hydrated alcohol feedstock inlet, a water outlet, and a crude alcohol feedstock outlet. The hydrated alcohol feedstock may be connected to the hydrated alcohol feedstock inlet, and the crude alcohol feedstock outlet may be connected to the crude alcohol feedstock.

[0080] In certain embodiments, the water separator is a fourth distillation column. In further embodiments, the fourth distillation column includes metal packing. In even further embodiments, the metal packing is random metal packing or structured metal packing.

[0081] The system may further include an ethanol purification column comprising an ethanol inlet and a pure ethanol outlet. The ethanol inlet may be connected to the ethanol outlet and configured to receive the ethanol product mixture from an extraction separator. In certain embodiments, the ethanol purification column is a fifth distillation column. The ethanol purification column may be configured to remove impurities from the ethanol product mixture. The impurities may be water and other impurities. The impurities may be, for example, water in amounts of about 50 to about 200 ppm or about 100 ppm. The fifth distillation column may include an absorbent bed. The absorbent bed may be made of any material known in the art to capture water and optionally other impurities from the ethanol product mixture. The absorbent bed may be packed with molecular sieves. The impurities may be propylene glycol in amounts of, for example, about 1 to about 50 ppm, about 1 to about 10 ppm, or less than about 10 ppm. The fifth distillation column can separate ethanol from trace amounts of propylene glycol.

[0082] As will be readily apparent to those skilled in the art, this system may, as necessary, include one or more heat exchangers, one or more condensers, and / or one or more reboilers located downstream of each separator.

[0083] Figure 1 shows an example of a system for processing a hydrated alcohol feedstock into an ethanol product and further providing a propylene glycol product mixture, which is a recirculated flow. As shown in the figure, the hydrated alcohol feedstock is introduced into a water separator 104 having a hydrated alcohol feedstock inlet 141, a water outlet 142, and a crude alcohol feedstock outlet 143. The crude water outlet 143 is connected to a crude water inlet 133 in a methanol separator 103. The methanol separator 103 also has a methanol outlet 134 and an alcohol feedstock outlet 135. The alcohol feedstock outlet 135 is connected to an alcohol feedstock inlet 114 in an extraction separator 101. The extraction separator 101 also has a propylene glycol feedstock inlet 111, an ethanol outlet 112, and a propylene glycol mixture outlet 113. The ethanol outlet 112 is shown to be connected to an ethanol outlet 151 in an ethanol purification column 105, which has a pure ethanol outlet 152. It is easy to imagine that this system could exist without including this ethanol purification column and still produce food-grade ethanol. The propylene glycol mixture outlet 113 is connected to the propylene glycol mixture inlet 123 in the propylene glycol separator 102. The propylene glycol separator 102 has a propanol outlet 122 and a propylene glycol outlet 121. The system is configured to combine the propylene glycol product mixture from the propylene glycol outlet 121 with the propylene glycol feedstock supplied through the propylene glycol feedstock inlet 111. It is easy to imagine that this system could exist without combining the propylene glycol product mixture from the propylene glycol outlet 121 with the propylene glycol feedstock.

[0084] Figure 2 shows the system and method of the present disclosure using two distillation columns for separating the flows. As shown in the figure, the propylene glycol feedstock 211 and the alcohol feedstock 212 are fed into an extraction distillation column 201 and combined (not shown) to form an ethanol product mixture 213 and a propylene glycol mixture 214. The propylene glycol mixture is supplied to a propylene glycol separator 202 to form a propanol product mixture 215 and a propylene glycol product mixture 216. The propanol product mixture 215 may contain a mixture of i-propanol and n-propanol. In this figure, the propylene glycol product mixture 216 is recycled and combined with propylene glycol in a mixer 217 to produce the propylene glycol feedstock 211, but it is easy to imagine that this system may exist without recycling the propylene glycol product mixture 216.

[0085] definition

[0086] Unless otherwise defined herein, scientific and technical terms used in this application have meanings that are generally understood by those skilled in the art. In general, the technical terms and techniques used in relation to chemistry and chemical engineering described herein are well known and commonly used in the art.

[0087] The methods and techniques described herein are generally carried out in accordance with the prior art methods well known in the art, unless otherwise indicated, and as described in the various general and more specific references cited and discussed throughout this specification.

[0088] Chemical terms used herein shall be used in accordance with their prior art usage, as exemplified in “The McGraw-Hill Dictionary of Chemical Terms”, Parker S., Ed., McGraw-Hill, San Francisco, CA (1985), unless otherwise defined herein.

[0089] All of the foregoing, and any other publications, patents, and published patent applications referenced herein, are incorporated herein by reference. In the event of any inconsistency, including specific definitions, this Specified Publication shall prevail.

[0090] In this disclosure, certain components of these systems and methods include “combining” reactants, feed streams, etc., or reactants, feed streams, etc., described as “combined” or “being combined.” Depending on the circumstances, the reactants, feed streams, etc., may be combined before entering a processing module (e.g., a reactor, reaction system, or separator), or they may be supplied individually to the processing module and combined therein. Thus, in some embodiments, these terms refer to combinations of feed streams, reactants, etc., before being supplied to a processing module. In some embodiments, these terms describe combinations of feed streams, reactants, etc., inside (or after being supplied to) subsequent reactors, reaction systems, separators, etc.

[0091] In this disclosure, certain components of these systems are described as “connected” to one another. As understood, the term “connected,” as used herein, describes components that are operationally linked to one another, but does not preclude the existence of components interposed between components said to be connected to one another. Furthermore, as understood, various system components are described as “having” certain features. Such descriptions do not preclude, nor do they particularly intend, the existence of additional features such as inlets, outlets, valves, control mechanisms, measuring devices, heating and / or cooling systems.

[0092] As used herein, the term “food grade” means that, under conditions of good manufacturing practices, the material can be safely used as a food additive for human consumption or as a component of an article that comes into contact with food for human consumption, in accordance with the requirements of the relevant regulations (e.g., the U.S. FDA). In a preferred embodiment, as will be understood by those skilled in the art, food grade ethanol conforms to U.S. FDA standards. Specifically, food grade ethanol meets the specifications of “Food Chemicals Codex,” 4th ed. (1996), p. 136, which is expressly incorporated herein by reference in its entirety. In a further preferred embodiment, as will be understood by those skilled in the art, food grade propylene glycol conforms to U.S. FDA standards. Specifically, food grade propylene glycol meets the specifications of Food Chemicals Codex, 3rd ed. (1981), p. 255, which is expressly incorporated herein by reference in its entirety.

[0093] As used herein, the term “molar ratio” means the ratio of the molar equivalent of X to the molar equivalent of Y, where X and Y may be, for example, different alcohols, water, or propylene glycol.

[0094] As used herein, the term “mass fraction” refers to the percentage of the mass of a substance in the total mass of a composition or a specific portion thereof. [Examples]

[0095] The present invention is described in general terms herein, but will be more readily understood by referring to the following examples, which are included solely for the purpose of illustrating certain aspects and embodiments of the present invention and are not intended to limit the present invention.

[0096] Example 1: General procedure for the separation of propanol from ethanol A feedstock mixture containing 99.5% (v / v) ethanol and 0.5% (v / v) i-propanol was placed in a flask containing 645 mL of propylene glycol (with a molar ratio of 1:2 between the feedstock mixture and propylene glycol) and distilled twice under reflux for 1 hour. Distillate samples were taken at 1.5 hours and 2 hours and analyzed by gas chromatography (Table 1). Furthermore, this procedure was modeled using Aspen, and the results are shown in Table 2. [Table 1] [Table 2]

[0097] Example 2: General procedure for recycling propylene glycol Propylene glycol recovery was performed using simple distillation. The feedstock, containing 1% (v / v) i-propanol, 85% (v / v) propylene glycol, and 14% (v / v) ethanol, was distilled twice under reflux in a column for 1 hour, and the recovered propylene glycol was then returned to the propylene glycol feedstock. Furthermore, this procedure was modeled in Aspen, and the results are shown in Tables 3 and 4. [Table 3] [Table 4]

[0098] Example 3: General procedure for separating water from an alcohol mixture The separation of water from the alcohol mixture was performed using distillation. A hydrated alcohol feedstock containing 31.533% (v / v) methanol, 0.39% (v / v) ethanol, and 67.80% (v / v) water was separated computationally (Table 5) and experimentally using Aspen (Table 6). The experimental conditions were as follows: feed rate: 15 kg / hr, reflux rate: 9.25 kg / hr, bottom heating: 40% (v / v) or 35% (v / v). The alcohol was pushed up to the top of the column, and the water remained at the bottom. After processing of stream 1, stream 2 was the crude alcohol feedstock, and stream 3 was the wastewater stream. [Table 5] [Table 6]

[0099] Built-in by reference All publications and patents referenced herein are incorporated herein by reference in whole, as if each individual publication or patent were specifically and individually indicated to be incorporated by reference. In the event of any inconsistency, including all definitions herein, this application shall prevail.

[0100] Equal portions While specific embodiments of the invention have been discussed, the above specification is illustrative and not limiting. Many variations of the invention will become apparent to those skilled in the art by a re-examination of this specification and the following claims. The full scope of the invention should be determined by referring the claims together with the full scope of equivalents, and by referring this specification together with such variations.

Claims

1. A method for purifying food-grade ethanol, (a) an alcohol supply material containing ethanol and propanol, and (b) a propylene glycol supply material containing propylene glycol, are combined to produce a purified supply material. The purified feedstock is distilled at the extraction distillation temperature and pressure to produce (a) an ethanol product mixture containing ethanol, and (b) a propylene glycol mixture containing propylene glycol and propanol, and The propylene glycol mixture is separated at separation temperature and separation pressure to produce (a) a propanol product mixture containing propanol and (b) a propylene glycol product mixture containing propylene glycol. Methods that include...

2. The method according to claim 1, wherein the propanol comprises i-propanol, n-propanol, or both i-propanol and n-propanol.

3. The method according to claim 1 or 2, wherein the extraction distillation temperature is approximately 50°C to approximately 150°C.

4. The method according to any one of claims 1 to 3, wherein the extraction distillation pressure is approximately 0 psig to approximately 15 psig.

5. The method according to any one of claims 1 to 4, wherein the molar ratio of the alcohol supply material to the propylene glycol supply material is about 1:1 to about 1:

3.

6. The method according to any one of claims 2 to 5, wherein the alcohol supplying raw material contains less than approximately 10% (v / v) of n-propanol.

7. The method according to any one of claims 2 to 6, wherein the alcohol supplying raw material contains less than 1% (v / v) i-propanol.

8. The method according to any one of claims 1 to 7, wherein the ethanol product mixture comprises about 90% (v / v) ethanol to about 100% (v / v) ethanol.

9. The method according to any one of claims 1 to 8, wherein the ethanol product mixture comprises about 95% (v / v) ethanol to about 100% (v / v) ethanol.

10. The method according to any one of claims 1 to 9, wherein the ethanol product mixture comprises about 99% (v / v) ethanol to about 100% (v / v) ethanol.

11. The method according to any one of claims 1 to 10, wherein the ethanol product mixture further comprises propanol.

12. The method according to claim 11, wherein the ethanol product mixture contains less than about 10% (v / v) of propanol.

13. The method according to claim 12, wherein the mass fraction of propanol to ethanol in the ethanol product mixture is more than 80% lower than the mass fraction of ethanol to propanol in the alcohol supply raw material.

14. The method according to claim 13, wherein the mass fraction of propanol to ethanol in the ethanol product mixture is about 90% lower than the mass fraction of ethanol to propanol in the alcohol supply raw material.

15. The method according to any one of claims 1 to 14, wherein the propylene glycol mixture comprises about 80% (v / v) propylene glycol to about 100% (v / v) propylene glycol.

16. The method according to any one of claims 1 to 15, wherein the propylene glycol mixture further comprises ethanol.

17. The method according to claim 16, wherein the propylene glycol mixture contains less than 10% (v / v) ethanol.

18. The method according to any one of claims 1 to 17, wherein the propylene glycol product mixture comprises about 90% (v / v) propylene glycol to about 100% (v / v) propylene glycol.

19. The method according to claim 18, wherein the propylene glycol product mixture further comprises propanol.

20. The method according to claim 19, wherein the propylene glycol product mixture contains less than about 10% (v / v) of propanol.

21. The method according to any one of claims 1 to 20, wherein the propanol product mixture comprises about 60% (v / v) propanol to about 100% (v / v) propanol.

22. The method according to any one of claims 1 to 21, wherein the propanol product mixture further comprises propylene glycol.

23. The method according to claim 22, wherein the propanol product mixture contains less than about 10% (v / v) propylene glycol.

24. The method according to any one of claims 1 to 23, wherein the propanol product mixture further comprises ethanol.

25. The method according to claim 24, wherein the propanol product mixture contains less than about 40% (v / v) ethanol.

26. The method according to any one of claims 1 to 25, further comprising combining a propylene glycol product mixture with a propylene glycol supply material.

27. A crude alcohol feedstock containing methanol, ethanol, and propanol is distilled at the crude alcohol distillation temperature and pressure to produce a methanol product mixture containing methanol and the alcohol feedstock. The method according to any one of claims 1 to 26, further comprising:

28. The method according to claim 27, wherein the crude alcohol distillation temperature is approximately 60°C to approximately 100°C.

29. The method according to either claim 27 or 28, wherein the crude alcohol distillation pressure is about 0 psig to about 15 psig.

30. The method according to any one of claims 1 to 29, wherein the alcohol supply raw material further comprises methanol.

31. The method according to claim 30, wherein the alcohol supply raw material contains less than approximately 0.1% (v / v) methanol.

32. The method according to claim 30 or 31, wherein the mass fraction of methanol to ethanol in the alcohol supply raw material is about 36% lower than the mass fraction of methanol to ethanol in the crude alcohol supply raw material.

33. The method according to claim 27, wherein the methanol product mixture is essentially free of ethanol.

34. The method according to claim 27, wherein the methanol product mixture is essentially free of ethanol or propanol.

35. A hydrated alcohol supply material containing water, methanol, ethanol, and propanol is separated at a hydrated alcohol separation temperature and hydrated alcohol separation pressure to produce a wastewater mixture containing water and a crude alcohol supply material. The method according to claim 27, further comprising:

36. The method according to claim 35, wherein the hydrated alcohol separation temperature is approximately 50°C to approximately 150°C.

37. The method according to any one of claims 35 or 36, wherein the hydration alcohol separation pressure is about 0 psig to about 15 psig.

38. The method according to any one of claims 35 to 37, wherein the hydrated alcohol supply raw material contains approximately 50% (v / v) water to approximately 100% (v / v) water.

39. The method according to any one of claims 35 to 38, wherein the hydrated alcohol supply raw material contains less than approximately 50% (v / v) methanol.

40. The method according to any one of claims 35 to 39, wherein the crude alcohol supply material further comprises water.

41. The method according to claim 40, wherein the mass fraction of water relative to methanol / ethanol / propanol in the crude alcohol feedstock is more than 90% lower than the mass fraction of water relative to methanol / ethanol / propanol in the hydrated alcohol feedstock.

42. The method according to claim 40 or 41, wherein the crude alcohol supply raw material contains less than approximately 70% (v / v) water.

43. The method according to any one of claims 40 to 42, wherein the crude alcohol supply raw material contains less than about 50% (v / v) water.

44. The method according to any one of claims 35 to 43, wherein the wastewater mixture further comprises methanol.

45. The method according to claim 44, wherein the wastewater mixture contains less than about 10% (v / v) methanol.

46. The method according to any one of claims 35 to 45, wherein the wastewater mixture contains about 90% (v / v) water to about 100% (v / v) water.

47. Alcohol supply raw materials, Propylene glycol supply raw materials, An extraction separator comprising an alcohol supply raw material inlet, a propylene glycol supply raw material inlet, an ethanol outlet, and a propylene glycol mixture outlet, wherein the alcohol supply raw material is connected to the alcohol supply raw material inlet, and the propylene glycol supply raw material is connected to the propylene glycol supply raw material inlet, and A propylene glycol separator comprising a propylene glycol mixture inlet, a propanol outlet, and a propylene glycol outlet, wherein the propylene glycol mixture inlet is connected to a propylene glycol mixture outlet from an extraction separator. A system for purifying food-grade ethanol, including [specific components / materials].

48. The system according to claim 47, wherein the extraction separator is a first distillation column.

49. The system according to claim 48, wherein the first distillation column includes a metal packing.

50. The system according to any one of claims 47 to 49, wherein the propylene glycol separator is a second distillation column.

51. The system according to claim 50, wherein the second distillation column includes a metal packing.

52. The system according to any one of claims 47 to 51, wherein the propylene glycol outlet from the propylene glycol separator is connected to the propylene glycol supply material.

53. Crude alcohol supply raw materials, and A methanol separator comprising a crude alcohol feedstock inlet, a methanol outlet, and an alcohol feedstock outlet, wherein the crude alcohol feedstock is connected to the crude alcohol feedstock inlet and the alcohol feedstock outlet is connected to the alcohol feedstock. The system according to any one of claims 47 to 52, further comprising:

54. The system according to claim 53, wherein the methanol separator is a third distillation column.

55. The system according to claim 54, wherein the third distillation column includes a metal packing.

56. Hydrated alcohol supply raw materials, and A water separator comprising a hydrated alcohol raw material inlet, a water outlet, and a crude alcohol raw material outlet, wherein the hydrated alcohol raw material is connected to the hydrated alcohol raw material inlet, and the crude alcohol raw material outlet is connected to the crude alcohol raw material. The system according to any one of claims 53 to 55, further comprising:

57. The system according to claim 56, wherein the water separator is a fourth distillation column.

58. The system according to claim 57, wherein the fourth distillation column includes a metal packing.

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