A methanol plant for the co-production of fusel oil and anhydrous ethanol
By employing a combined process of dehydration tower, methanol tower, ethanol tower, stripping tower, and membrane modules in the methanol production process, and combining double-effect or triple-effect thermal integration and membrane dehydration technology, the problem of difficult recovery of substances such as ethanol in fusel oil has been solved, achieving efficient and low-energy co-production of anhydrous ethanol.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NEW TIANJIN T & D
- Filing Date
- 2025-04-24
- Publication Date
- 2026-06-09
AI Technical Summary
In the current methanol production process, substances such as ethanol in fusel oil are difficult to recover effectively, resulting in substandard product quality, high energy consumption, and poor economic benefits.
A combined process of dehydration tower, methanol tower, ethanol tower, stripping tower and membrane module is adopted. Through double-effect or triple-effect thermal integration and membrane dehydration technology, methanol in fusel oil is recovered and anhydrous ethanol is produced in combination, optimizing heat utilization to reduce energy consumption.
It significantly reduced operating energy consumption, with steam consumption dropping to below 2.9 tons of steam per ton, enabling the co-production of high-purity methanol and anhydrous ethanol, and improving economic efficiency.
Smart Images
Figure CN224331529U_ABST
Abstract
Description
Technical Field
[0001] This utility model provides an apparatus for a process of co-producing anhydrous ethanol from fusel oil in a methanol plant. It can be used to improve the quality and efficiency of fusel oil produced by various methanol plants, recover methanol, and co-produce anhydrous ethanol. Background Technology
[0002] In methanol production, due to the selectivity of methanol synthesis catalysts, ethanol and higher alcohols are inevitably generated during the methanol synthesis process. In particular, the amount of ethanol and other alcohols increases significantly in the later and final stages of methanol synthesis catalyst use. In order to obtain refined methanol that meets the quality requirements of methanol products, the synthesized crude methanol needs to be refined. CN101503337B discloses a process for methanol distillation using a five-tower integrated thermal device, which is a typical five-tower three-effect distillation process. Tower T101 is a pre-distillation tower, tower T102 is an atmospheric distillation tower, tower T103 is a low-pressure distillation tower, tower T104 is a pressurized distillation tower, and tower T105 is a recovery tower (baffle tower). Ethanol and other substances (mainly water, methanol, ethanol, and isopropanol) are collected from the ethanol side of the recovery tower and enter the fusel oil tank. Higher carbon fusel oils (mainly water, methanol, and butanol) are collected from the lower part of the wastewater side and enter the fusel oil tank for further disposal. Because fusel oils have complex compositions and cannot be used as qualified products, they are generally classified as hazardous waste for outsourced treatment or used as boiler fuel within the plant area, which either increases the operating cost of the device or results in low added value and poor economic benefits.
[0003] Chinese patent CN 110759812 A discloses a process method and system for recovering ethanol fusel oil in a methanol distillation process. The distillation tower and ethanol distillation tower in this method are combined to form the methanol recovery tower in Chinese patent CN 106582053B. The ethanol distillation tower in this method is equivalent to the ethanol side of the recovery tower in a double triple-effect distillation process. The recovered ethanol has low purity and cannot be sold as a qualified ethanol product. This does not solve the above-mentioned defects.
[0004] CN 114539027 A discloses a "Comprehensive Utilization Method for Fusel Oil Resources in a Methanol Distillation Process," characterized by the following: after phase separation of the fusel oil, methanol and ethanol are recovered from the aqueous phase. However, various soluble fusel oils, such as isopropanol and n-propanol, still exist in the aqueous phase. In this method, the methanol recovery tower can recover methanol from the aqueous phase, but the ethanol recovery tower recovers ethanol with low purity, failing to remove isopropanol and other fusel oils, and therefore cannot be sold as a qualified ethanol product. Furthermore, each tower operates on a single-effect basis, resulting in high energy consumption.
[0005] CN 206986063 U discloses "A system for extracting refined methanol and anhydrous ethanol from crude methanol." This patent further separates the fusel oil produced within the system, recovering methanol and ethanol from the fusel oil to obtain anhydrous ethanol. However, the fusel oil recovery tower, methanol recovery tower, and ethanol recovery tower are all single-effect, resulting in high energy consumption and minimal added value to the recovered products. Furthermore, the ethanol recovery tower lacks a light component removal function, meaning the recovered ethanol product inevitably contains light components between the boiling points of methanol and ethanol, or organic impurities that azeotropically interact with ethanol (such as ethyl acetate).
[0006] CN 212594874 U discloses a "fusel oil recycling device in methanol production". This device vaporizes all the fusel oil from the methanol distillation unit before feeding it into a membrane dehydration unit. Because the fusel oil has a high water content, complete vaporization requires a large amount of steam, and since it is not pre-dehydrated, the membrane module area is large, resulting in high investment. Although it can recover methanol from the fusel oil and obtain anhydrous ethanol, the high steam consumption results in low added value from the recovered product and poor economic benefits.
[0007] CN 107488104 A discloses "an energy-saving distillation system and energy-saving distillation method for purifying fusel oil". This method uses extractive distillation to dehydrate the fuel oil. Although it can recover methanol from the fusel oil and obtain anhydrous ethanol product, the energy consumption reaches 9.8t steam / t methanol + ethanol, which is too high. Summary of the Invention
[0008] The purpose of this invention is to provide an apparatus for the co-production of anhydrous ethanol from fusel oil in a methanol plant, which can significantly reduce operating energy consumption. It can be used to improve the quality and efficiency of fusel oil produced in various methanol plants, recover methanol, and co-produce anhydrous ethanol.
[0009] This utility model provides a process method for co-producing anhydrous ethanol from fusel oil in a methanol plant, which mainly includes the following steps:
[0010] 1) It includes at least four towers: dehydration tower T101, methanol tower T102, ethanol tower T103, and stripping tower T104, as well as membrane module PU101;
[0011] 2) After the fusel oil feedstock is preheated, it enters the dehydration tower T101. The liquid phase collected from the top of the dehydration tower T101 enters the methanol tower T102.
[0012] 3) The liquid phase from the bottom of methanol tower T102 enters vaporization tank V102;
[0013] 4) The vapor phase of vaporization tank V102 enters membrane module PU101;
[0014] 5) The anhydrous gas phase from the membrane assembly PU101 is condensed and then enters the ethanol tower T103;
[0015] 6) The liquid phase collected from the side stream of ethanol tower T103 enters stripping tower T104;
[0016] 7) The dehydration tower T101 and the methanol tower T102 are connected by a double-effect thermal integration. The gas phase at the top of the dehydration tower T101 serves as the heat source for heating the bottom of the methanol tower T102, providing the required heat for the methanol tower T102.
[0017] 8) The membrane module PU101 and the ethanol tower T130 adopt a double-effect thermal integration. The anhydrous alcohol gas from the membrane module PU101 is used as the heat source for heating the bottom of the ethanol tower T103, providing part of the heat for the ethanol tower T103. The remaining heat required is supplemented by steam.
[0018] 9) The fusel oil collected from the dehydration tower T101 is cooled and then sent to the phase separation tank V101 for phase separation. The oil phase is discharged as a higher alcohol; the water phase is returned to the dehydration tower T101; the bottom liquid of the dehydration tower T101 is cooled and discharged as wastewater.
[0019] 10) Methanol is recovered from the top of methanol tower T102; light components are collected from the top of ethanol tower T103, and the bottom liquid is cooled and discharged as higher alcohols; the bottom liquid of stripping tower T104 is cooled and sent to the product tank as ethanol product.
[0020] The apparatus for the co-production of anhydrous ethanol from fusel oil in a methanol plant provided by this utility model can recover methanol from fusel oil and produce anhydrous ethanol as a byproduct, while significantly reducing operating energy consumption.
[0021] This utility model provides a process for co-producing anhydrous ethanol from fusel oil in a methanol plant. It overcomes the shortcomings of the prior art, and can obtain refined methanol or methanol with a purity of more than 99.5% to be returned to the methanol distillation unit, while producing anhydrous ethanol as a byproduct. The steam consumption can be reduced to less than 2.9 tons of steam / ton (methanol + anhydrous ethanol), which has significant practicality and economic benefits and broad application prospects.
[0022] The apparatus according to the process method provided by this utility model comprises the following steps:
[0023] Fusel oil feedstock 1 is preheated by feedstock preheater E101, and feedstock 2 enters dehydration tower T101.
[0024] The dehydration tower T101 and methanol tower T102 are thermally integrated. The gas phase 3 at the top of the dehydration tower T101 enters the methanol tower reboiler E103 for condensation. The condensed liquid 4 is divided into two streams. One stream is used as the dehydration tower reflux 5 and returned directly to the top of the dehydration tower T101. The other stream of condensed liquid 6 enters the methanol tower. The fusel oil 7 collected from the side stream of the dehydration tower T101 is cooled by the fusel oil cooler E104 and then enters the phase separation tank V101. The aqueous phase 11 of the phase separation tank V101 is returned to the dehydration tower T101. The material 10 of the bottom material 9 of the dehydration tower T101 is cooled by the wastewater cooler E113 and then used as the wastewater discharge device.
[0025] The vapor phase 13 at the top of methanol tower T102 is condensed by methanol tower condenser E105 and then divided into two streams. One stream is returned directly to the top of methanol tower T102 as reflux liquid 14, and the other stream of condensate 15 is collected as methanol product. The bottom material 16 of methanol tower T102 enters the gasification tank V102.
[0026] The gas phase 17 from vaporizer V102 enters membrane module PU101. The pervapor 20 from membrane module PU101 is condensed by membrane module condenser E108, and the condensate 21 enters phase separation tank V101. The membrane module PU101 is thermally integrated with ethanol tower T103. The anhydrous alcohol gas 18 from membrane module PU101 enters the shell side of reboiler E107 of ethanol tower #1, and the condensate 19 enters ethanol tower T103.
[0027] The vapor phase 22 at the top of ethanol tower T103 is condensed by ethanol tower condenser E110, and the condensate 23 is divided into two streams. One stream is returned directly to the top of ethanol tower T103 as reflux liquid 24, and the other stream of condensate 25 is collected as a light component. The liquid phase 27 collected from the side stream of ethanol tower T103 is fed into stripping tower T104. The mixture 31 of the material 28 at the bottom of ethanol tower T103 and the oil phase 12 in phase separator V101 is cooled by higher alcohol cooler E114, and the resulting stream 32 is used as a higher alcohol discharge device.
[0028] The vapor phase 26 from the top of the stripping tower T104 is returned to the ethanol tower T103, and the bottom liquid 29 is cooled by the ethanol cooler E112, and the material 30 is sent out of the unit as ethanol product.
[0029] The methanol tower reboiler E103, the vaporizer reboiler E106, the ethanol tower #2 reboiler E109, and the stripping tower reboiler E111 can be heated by fresh steam, or by secondary steam or other high-temperature materials within the system. The raw material preheater (E101) can use the system's steam condensate, dehydration tower bottom liquid 9, stripping tower bottom liquid 29, or other high-temperature materials as a heat source.
[0030] In the apparatus of the above-described process method, in the membrane dehydration PU101 unit, in order to simplify the process, the membrane module PU101 adopts the following liquid phase membrane module deformation process, which can reduce the vaporization device and anhydrous alcohol vapor condensation equipment of the membrane module, thereby reducing investment.
[0031] The methanol tower T102 bottom liquid 16 enters the liquid phase membrane module PU101. The permeate 20 exiting the membrane module PU101 is condensed by the membrane module condenser E108, and the resulting material 21 enters the phase separation tank V101. The anhydrous material 18 exiting the membrane module PU101 enters the ethanol tower T103.
[0032] According to the process method provided by the device of this utility model, when the energy consumption requirements of the device are high, the following modified process of triple effect can be adopted to reduce steam consumption and thus reduce operating costs.
[0033] 1) The gas at the top of the dehydration tower T101 is divided into two streams. One stream is used as the top gas of the dehydration tower and enters the membrane module PU101. The other stream is used as the reboiler of the methanol tower E103. The condensate 5 from E103 is returned to the top of the dehydration tower T101. The anhydrous gas 18 from the membrane module PU101 enters the reboiler of the vaporizer E106. The condensate 19 from the reboiler of the vaporizer E106 enters the methanol tower T102. The dehydration tower T101, methanol tower T102, and ethanol tower T103 are connected by a triple-effect thermal integration. The gas phase at the top of the dehydration tower T101 serves as the heat source for heating the bottom of the methanol tower T102, providing heat to the methanol tower T102. The anhydrous gas from the outlet membrane module PU101 also heats the bottom of the methanol tower T102. The gas phase at the top of the methanol tower T102 serves as the heat source for heating the bottom of the ethanol tower T103, providing the required heat to the ethanol tower T103.
[0034] 2) The top of the dehydration tower T101 produces 6 units of anhydrous liquid, which enters the liquid membrane module PU101. The anhydrous liquid from the membrane module PU101 enters the methanol tower T102. The dehydration tower T101, methanol tower T102, and ethanol tower T103 are connected by a triple-effect thermal integration system. The vapor phase from the top of the dehydration tower T101 serves as the heat source for heating the bottom of the methanol tower T102, providing heat to the methanol tower T102. Similarly, the vapor phase from the top of the methanol tower T102 serves as the heat source for heating the bottom of the ethanol tower T103, providing the necessary heat to the ethanol tower T103.
[0035] When the recovered ethanol does not require the extraction of anhydrous ethanol, the apparatus of the process method provided by this utility model can adopt the following modified process, which eliminates the membrane dehydration unit and reduces equipment investment.
[0036] The bottom liquid 16 of the methanol tower T102 goes directly to the ethanol tower T103. The dehydration tower T101 and the methanol tower T102 are connected by a double-effect heat integration. The gas phase at the top of the dehydration tower T101 serves as the heat source for heating the bottom of the methanol tower T102, providing heat for the methanol tower T102.
[0037] According to the apparatus of the process method provided by this utility model, when the quality requirements of ethanol products are not high in the four towers, the following modified process can be adopted to reduce equipment investment and land occupation.
[0038] The stripping tower T104 is omitted, and a three-tower process is adopted. The ethanol product is drawn from the side stream of the ethanol tower or from the top of the tower.
[0039] According to the process method provided by this utility model, when the scale of the device is large and the floor space is limited, the following modified process can be adopted to reduce the floor space and reduce equipment investment.
[0040] Ethanol tower T103 and stripping tower T104 are combined into one ethanol tower T103 using a partition. A partition is installed inside the tower to divide the lower part of ethanol tower T103 into a feed side and an ethanol collection side. Higher alcohol 28 is discharged from the bottom of the feed side tower, and ethanol product 29 is discharged from the bottom of the ethanol side tower.
[0041] According to the apparatus of the process method provided by this utility model, when the membrane module is moved forward between the dehydration tower and the methanol tower, the following modified process can be adopted to reduce the number of equipment, thereby reducing the floor space and investment.
[0042] The side stream of dehydration tower T101 can be exempted from producing fusel oil, reducing the need for fusel oil cooler E104 and phase separation tank V101; fusel oil is extracted from the top of the tower along with methanol and ethanol; the permeate 21 from the membrane assembly PU101 is directly returned to the lower part of dehydration tower T101; at this time, the heating amount of the bottom of dehydration tower T101 can be reduced to lower operating energy consumption, reduce the tower diameter and investment; methanol tower T102 needs to be equipped with a fresh steam reboiler E116 to supplement the required heat with fresh steam.
[0043] According to the process method provided by this utility model, the typical operating conditions for each tower (unless otherwise specified, all pressures below are absolute pressures) are as follows:
[0044] The operating pressure range at the top of the T101 dehydration tower is 80–900 kPa.
[0045] The operating pressure range at the top of methanol tower T102 is 30–600 kPa;
[0046] The operating pressure range at the top of the T103 ethanol column is 20–300 kPa.
[0047] The operating pressure range at the top of the T104 stripping tower is 20–300 kPa.
[0048] The preferred operating conditions for each tower are as follows:
[0049] The operating pressure at the top of the T101 dehydration tower is 140–220 kPa, the operating temperature at the top of the tower is 79–90 °C, and the operating temperature at the bottom of the tower is 110–125 °C.
[0050] The methanol tower T102 has an operating pressure of 50–101 kPa at the top, an operating temperature of 45–64°C at the top, and an operating temperature of 60–80°C at the bottom.
[0051] The operating pressure at the top of the ethanol tower T103 is 30–105 kPa, the operating temperature at the top is 45–80℃, and the operating temperature at the bottom is 61–96℃.
[0052] The operating pressure at the top of the T104 stripping tower is 31–106 kPa, the operating temperature at the top is 46–81 °C, and the operating temperature at the bottom is 47–82 °C.
[0053] According to the apparatus of the process method provided by this utility model, the membrane module PU101 can be replaced by a conventional molecular sieve adsorption bed T105A / B. Two or more molecular sieve adsorption beds are used for adsorption and desorption switching operations to realize the dehydration process of the material. This reduces the investment in the dehydration process.
[0054] The apparatus according to the process method provided by this utility model mainly includes a dehydration tower T101, a methanol tower T02, an ethanol tower T103, a stripping tower T104, a membrane module PU101, and connecting pipelines.
[0055] The raw material fusel oil pipeline is connected to the cold side inlet of the raw material preheater E101; the cold side outlet of the raw material preheater E101 is connected to the middle of the dehydration tower T101; the top of the dehydration tower T101 is connected to the shell-side inlet of the methanol tower reboiler E103, and the condensate outlet of the shell-side reboiler E103 is connected to the top of the dehydration tower T101 and the middle of the methanol tower T102, respectively; the middle of the dehydration tower T101 is connected to the hot side inlet of the fusel oil cooler E104, and the hot side outlet of the fusel oil cooler E104 is connected to the phase separation tank V101; the oil phase outlet of the phase separation tank is connected to the hot side inlet of the higher alcohol cooler E114, and the water phase outlet is connected to the lower middle part of the dehydration tower T101; the bottom of the dehydration tower T101 is connected to the tube-side inlet of the dehydration tower reboiler E102 and the hot side inlet of the wastewater cooler E113, respectively.
[0056] The top of methanol tower T102 is connected to methanol tower condenser E105, and the condensate outlet of methanol tower condenser E105 is connected to the top of methanol tower T102 and the methanol collection pipeline, respectively. The bottom of methanol tower T102 is connected to the tube inlet of methanol tower reboiler E103 and vaporization tank V102, respectively, and the tube outlet of methanol tower reboiler E103 is connected to the bottom of methanol tower T102.
[0057] The bottom of vaporizer V102 is connected to the tube-side inlet of reboiler E106, and the tube-side outlet of reboiler E106 is connected to vaporizer V102; the gas phase outlet at the top of vaporizer is connected to the inlet of membrane module PU101; the permeate-side outlet of membrane module PU101 is connected to the shell-side inlet of condenser E108, and the condensate outlet of condenser E108 is connected to the phase separation tank; the tube-side outlet of membrane module PU101 is connected to the shell-side inlet of reboiler E107 in ethanol tower #1, and the condensate outlet of reboiler E107 in ethanol tower #1 is connected to the middle of ethanol tower T103.
[0058] The top of ethanol tower T103 is connected to the shell side of ethanol tower condenser E110. The condensate outlet of the shell side of ethanol tower condenser E110 is connected to the top of ethanol tower T103 and the light component collection pipeline, respectively. The upper middle part of the ethanol tower is connected to the top of stripping tower T104. The bottom of ethanol tower T103 is connected to the tube side inlet of ethanol tower reboiler E107, the tube side inlet of ethanol tower reboiler E109, and the hot side inlet of higher alcohol cooler E114, respectively. The tube side outlets of ethanol tower reboiler E107 and E109 are both connected to the bottom of ethanol tower T103.
[0059] The top of stripping tower T104 is connected to the upper middle part of ethanol tower T103; the bottom of stripping tower T104 is connected to the tube inlet of stripping tower reboiler E111 and the hot side inlet of ethanol cooler E112 respectively.
[0060] The raw material preheater E101 exchanges heat with the steam condensate in the system; the hot side outlet of the ethanol cooler E112 is connected to the ethanol product collection pipeline; the hot side outlet of the wastewater cooler E113 is connected to the wastewater collection pipeline; and the hot side outlet of the higher alcohol cooler E114 is connected to the higher alcohol collection pipeline.
[0061] To highlight the apparatus for the co-production of anhydrous ethanol from fusel oil in a methanol plant provided by this utility model, some heat exchangers in the process flow are omitted. Those skilled in the art can implement suitable internal heat exchange methods for the system's internal materials based on the specific plant conditions, and all resulting variations in the process flow should be considered within the spirit, scope, and content of this utility model. The heat exchangers in the simplified flow diagram are merely illustrative, and their specific structural forms do not constitute any limitation on this utility model.
[0062] The apparatus described in this invention, which utilizes a process for the co-production of anhydrous ethanol from fusel oil in a methanol plant, can recover methanol from the fusel oil and produce anhydrous ethanol or other grades of ethanol as byproducts, while significantly reducing operating energy consumption. It overcomes the shortcomings of existing technologies, reducing product steam consumption to below 2.9 tons of steam / ton (methanol + anhydrous ethanol), demonstrating significant practicality and economic benefits, and showing broad application prospects. Attached Figure Description
[0063] Figure 1 This utility model provides a process flow diagram of the apparatus for recovering fusel oil in a methanol plant process for co-producing anhydrous ethanol from fusel oil.
[0064] Figure 2 yes Figure 1 One type of evolutionary process, namely, modified process method one, is relatively... Figure 1 The provided process, based on the combination of the four towers and membrane module PU101, allows the membrane module PU101 to be a liquid phase membrane module: the outlet of the methanol tower T102 bottom liquid is connected to the inlet of the liquid phase membrane module PU101; the outlet of the liquid phase membrane module PU101 is connected to the feed inlet of the ethanol tower T103.
[0065] Figure 3 yes Figure 1 One type of evolutionary process, namely, modified process method two, is relatively... Figure 1 The provided process, based on the combination of the four towers and membrane module PU101, allows membrane module PU101 to be moved between dehydration tower T101 and methanol tower T102 using a gas phase membrane (gas phase dehydration membrane): the top of dehydration tower T101 is connected to both the tube-side inlet of membrane module PU101 and the shell-side inlet of methanol tower reboiler E103; the tube-side outlet of membrane module PU101 is connected to the shell-side inlet of reboiler E106 in the vaporizer, and the shell-side outlet of reboiler E106 is connected to... The feed inlet of methanol tower T102 is connected; the bottom of methanol tower T102 is connected to the tube inlet of methanol tower reboiler E103, the tube inlet of vaporizer reboiler E106, and the feed inlet of ethanol tower T103, respectively; the tube outlet of vaporizer reboiler E106 is connected to methanol tower T102; the top of methanol tower T102 is connected to the shell inlet of ethanol tower reboiler E107; the condensate in the shell of ethanol tower reboiler E107 is connected to the top of methanol tower T102 and the methanol outlet pipeline, respectively.
[0066] Figure 4 yes Figure 1 One of the evolutionary process methods, namely the modified process method three, is relatively... Figure 1The provided process, based on the combination of the four towers and membrane module PU101, allows the membrane module PU101 to be moved between the dehydration tower T101 and the methanol tower T102 using a liquid phase membrane (liquid phase dehydration membrane): the shell-side outlet of the methanol tower reboiler E103 is connected to the tube-side inlet of membrane module PU101 and the top of the dehydration tower T101, respectively; the tube-side outlet of membrane module PU101 is connected to the feed inlet of the methanol tower T102; the bottom of the methanol tower T102 is connected to the tube-side inlet of the methanol tower reboiler E103 and the feed inlet of the ethanol tower T103, respectively; the top of the methanol tower T102 is connected to the shell-side inlet of the ethanol tower reboiler E107, and the condensate from the shell side of the ethanol tower reboiler E107 is connected to the top of the methanol tower T102 and the methanol collection pipeline, respectively.
[0067] Figure 5 yes Figure 1 One type of evolutionary process, namely, modified process method four, is relatively... Figure 1 The provided process reduces the number of membrane modules PU101, resulting in a 4-tower process: the outlet of the methanol tower T102 is connected to the feed inlet of the ethanol tower T103.
[0068] Figure 6 yes Figures 1-5 One of the evolutionary process methods, namely, the fifth modified process method, is relatively... Figures 1-5 The provided process reduces the stripping tower T104, allowing ethanol products to be drawn from the side stream of ethanol tower T103 or from the top of the tower.
[0069] Figure 7 yes Figures 1-5 One type of evolutionary process, namely, variation process method six, is relatively... Figures 1-5 The provided process combines ethanol tower T103 and stripping tower T104 into a single ethanol tower T103 using a partition, resulting in a process flow of three towers: the ethanol-side reboiler of ethanol tower T103 is connected to the tube-side inlet of the ethanol-side reboiler E115 and the hot-side inlet of the ethanol cooler E112, respectively, and the tube-side outlet of the ethanol-side reboiler E115 is connected to the ethanol side of ethanol tower T103.
[0070] Figure 8 yes Figure 3 , Figure 4 One type of evolutionary process, namely, modified process method seven, is relatively... Figure 3 , Figure 4 The provided process reduces the number of fusel oil coolers E104 and phase separation tanks V101, connects the shell-side condensate outlet of membrane module condenser E108 to the lower part of dehydration tower T101, and adds a steam reboiler E116 to the bottom of methanol tower T102.
[0071] Figure 9 yes Figure 1 , Figure 3 One type of evolutionary process, namely, variation process method eight, relative to Figure 1 , Figure 3 The provided process allows the membrane module (PU101) to be replaced by a conventional molecular sieve adsorption bed T105A / B. Two or more molecular sieve adsorption beds are used to switch between adsorption and desorption to achieve the dehydration process of the material.
[0072] According to the apparatus of the process method provided by this utility model and the apparatus of the above-mentioned modified process method, those skilled in the relevant professional fields can fully implement appropriate internal material heat exchange methods according to specific apparatus conditions. The apparatus of various evolved process flows formed therefrom should be regarded as being within the spirit, scope and content of this utility model. Detailed Implementation
[0073] The specific implementation scheme of this utility model is described in detail below with reference to the accompanying drawings, but it is only for illustration and not for limiting this utility model.
[0074] Unless otherwise specified, the composition, structure, materials (such as connecting pipelines between towers), reagents, etc., of the process equipment used in the embodiments that are not specifically described can all be obtained commercially or by methods known to those skilled in the art. The specific experimental methods and operating conditions involved are generally in accordance with conventional process conditions and the conditions described in the manual, or the conditions recommended by the manufacturer.
[0075] Application Example 1:
[0076] The typical composition of fusel oil feedstock is as follows:
[0077] Component mass percentage (%)
[0078] Water 27.32
[0079] Methanol 35.17
[0080] Ethanol 19.72
[0081] n-Propanol 6.41
[0082] Isopropanol 2.47
[0083] n-Butanol 7.40
[0084] n-Pentanol 1.48
[0085] Light component 0.037
[0086] Total: 100.00
[0087] The above-mentioned range of raw material composition does not constitute any limitation on this utility model. This utility model can be used in the distillation process of producing anhydrous ethanol from fusel oils of various compositions produced by methanol plants.
[0088] like Figure 1 As shown, the fusel oil feedstock 1 is preheated by the feedstock preheater E101, and the feedstock 2 enters the dehydration tower T101.
[0089] The dehydration tower T101 and methanol tower T102 are thermally integrated. The gas phase 3 at the top of the dehydration tower T101 enters the methanol tower reboiler E103 for condensation. The condensed liquid 4 is divided into two streams. One stream is used as the dehydration tower reflux 5 and returned directly to the top of the dehydration tower T101. The other stream of condensed liquid 6 enters the methanol tower. The fusel oil 7 collected from the side stream of the dehydration tower T101 is cooled by the fusel oil cooler E104 and then enters the phase separation tank V101. The aqueous phase 11 of the phase separation tank V101 is returned to the dehydration tower T101. The material 10 of the bottom material 9 of the dehydration tower T101 is cooled by the wastewater cooler E113 and then used as the wastewater discharge device.
[0090] The vapor phase 13 at the top of methanol tower T102 is condensed by methanol tower condenser E105 and then divided into two streams. One stream is returned directly to the top of methanol tower T102 as reflux liquid 14, and the other stream of condensate 15 is collected as methanol product. The bottom material 16 of methanol tower T102 enters the gasification tank V102.
[0091] The gas phase 17 from vaporizer V102 enters membrane module PU101. The pervapor 20 from membrane module PU101 is condensed by membrane module condenser E108, and the condensate 21 enters phase separation tank V101. The membrane module PU101 is thermally integrated with ethanol tower T103. The anhydrous alcohol gas 18 from membrane module PU101 enters the shell side of reboiler E107 of ethanol tower #1, and the condensate 19 enters ethanol tower T103.
[0092] The vapor phase 22 at the top of ethanol tower T103 is condensed by ethanol tower condenser E110, and the condensate 23 is divided into two streams. One stream is returned directly to the top of ethanol tower T103 as reflux liquid 24, and the other stream of condensate 25 is collected as a light component. The liquid phase 27 collected from the side stream of ethanol tower T103 is fed into stripping tower T104. The mixture 31 of the material 28 at the bottom of ethanol tower T103 and the oil phase 12 in phase separator V101 is cooled by higher alcohol cooler E114, and the resulting stream 32 is used as a higher alcohol discharge device.
[0093] The vapor phase 26 from the top of the stripping tower T104 is returned to the ethanol tower T103, and the bottom liquid 29 is cooled by the ethanol cooler E112, and the material 30 is sent out of the unit as ethanol product.
[0094] The typical operating conditions for each tower in Example 1 are given below:
[0095] The operating pressure range at the top of the T101 dehydration tower is 80–900 kPa.
[0096] The operating pressure range at the top of methanol tower T102 is 30–600 kPa;
[0097] The operating pressure range at the top of the ethanol tower T103 is 20–300 kPa;
[0098] The operating pressure range at the top of the T104 stripping tower is 20–300 kPa.
[0099] The preferred operating conditions and operating energy consumption for each tower in Example 1 are given below:
[0100] The operating pressure at the top of the T101 dehydration tower is 160–450 kPa, the operating temperature at the top of the tower is 82–131 °C, and the operating temperature at the bottom of the tower is 115–152 °C.
[0101] The methanol tower T102 has an operating pressure of 50–300 kPa at the top, an operating temperature of 45–95°C at the top, and an operating temperature of 60–113°C at the bottom.
[0102] The operating pressure at the top of the ethanol tower T103 is 30–105 kPa, the operating temperature at the top is 45–80℃, and the operating temperature at the bottom is 61–96℃.
[0103] The operating pressure at the top of the T104 stripping tower is 31–106 kPa, the operating temperature at the top is 46–81 °C, and the operating temperature at the bottom is 47–82 °C.
[0104] All external heating sources can be low-pressure steam heating. Using this invention, refined methanol can be obtained, and anhydrous ethanol can be produced as a byproduct. The steam consumption can be reduced to below 2.9 tons of steam / ton (methanol + anhydrous ethanol), which has significant practicality and economic benefits and broad application prospects.
[0105] Application Example 2:
[0106] like Figure 2 As shown, it is Figure 1 An evolved process method, relatively Figure 1 The provided process, based on the combination of the four towers and membrane module PU101, allows the membrane module PU101 to be a liquid phase dehydration membrane module; the outlet of the methanol tower T102 bottom liquid is connected to the inlet of the liquid phase membrane module PU101; and the outlet of the liquid phase membrane module PU101 is connected to the feed inlet of the ethanol tower T103.
[0107] Application Example 3:
[0108] like Figure 3 As shown, it is Figure 1 An evolved process method, relatively Figure 1The provided process involves membrane module PU101 being moved between dehydration tower T101 and methanol tower T102 via a gas-phase dehydration membrane; the top of dehydration tower T101 is connected to the tube-side inlet of membrane module PU101 and the shell-side inlet of methanol tower reboiler E103; the tube-side outlet of membrane module PU101 is connected to the shell-side inlet of vaporizer reboiler E106, and the shell-side outlet of vaporizer reboiler E106 is connected to the feed inlet of methanol tower T102; the bottom of methanol tower T102 is connected to the tube-side inlet of methanol tower reboiler E103, the tube-side inlet of vaporizer reboiler E106, and the feed inlet of ethanol tower T103, and the tube-side outlet of vaporizer reboiler E106 is connected to methanol tower T102; the top of methanol tower T102 is connected to the shell-side inlet of ethanol tower reboiler E107, and the condensate from the shell side of ethanol tower reboiler E107 is connected to the top of methanol tower T102 and the methanol collection pipeline.
[0109] The external heating source of this invention can be low-pressure steam, which can produce refined methanol and anhydrous ethanol as a byproduct. The steam consumption can be reduced to less than 1.3 tons of steam / ton (methanol + anhydrous ethanol), which has significant practicality and economic benefits and broad application prospects.
[0110] Application Example 4:
[0111] like Figure 4 As shown, it is Figure 1 An evolved process method, relatively Figure 1 The provided process involves membrane module PU101 being moved between dehydration tower T101 and methanol tower T102 using a liquid-phase dehydration membrane: the shell-side outlet of methanol tower reboiler E103 is connected to the tube-side inlet of membrane module PU101 and the top of dehydration tower T101, respectively; the tube-side outlet of membrane module PU101 is connected to the feed inlet of methanol tower T102; the bottom of methanol tower T102 is connected to the tube-side inlet of methanol tower reboiler E103 and the feed inlet of ethanol tower T103, respectively; the top of methanol tower T102 is connected to the shell-side inlet of ethanol tower reboiler E107, and the condensate from the shell side of ethanol tower reboiler E107 is connected to the top of methanol tower T102 and the methanol collection pipeline, respectively.
[0112] Application Example 5:
[0113] like Figure 5 As shown, it is Figure 1 An evolved process method, relatively Figure 1 The provided process reduces the number of membrane modules (PU101) to a 4-tower process: the outlet of the methanol tower (T102) is connected to the inlet of the ethanol tower (T103). Using this invention, all external heating sources can be low-pressure steam, which can produce refined methanol and industrial alcohol as a byproduct. Steam consumption can be reduced to below 2.5 tons of steam / ton (methanol + anhydrous ethanol), demonstrating significant practicality and economic benefits, and promising broad application prospects.
[0114] This invention provides an apparatus for the co-production of anhydrous ethanol from fusel oil in a methanol plant. It can be used to improve the quality and efficiency of fusel oil produced by various methanol plants, recover methanol and co-produce anhydrous ethanol, and significantly reduce operating energy consumption. It has significant practical and economic benefits and broad application prospects.
[0115] The embodiments are described in detail below. Those skilled in the art can make appropriate modifications, alterations, and combinations based on the methods provided by this utility model to achieve the same technology. It should be particularly noted that all such modifications, alterations, and recombinations of the process flow provided by this utility model are obvious to those skilled in the art and are considered to be within the spirit, scope, and content of this utility model.
Claims
1. An apparatus for a process of co-producing anhydrous ethanol from fusel oil in a methanol plant, characterized in that: It includes at least four towers: a dehydration tower (T101), a methanol tower (T102), an ethanol tower (T103), and a stripping tower (T104), as well as a membrane module (PU101) and connecting pipelines; The feedstock fusel oil is connected to the cold-side inlet of the feedstock preheater (E101); the cold-side outlet of the feedstock preheater (E101) is connected to the middle section of the dehydration tower (T101); the top of the dehydration tower (T101) is connected to the hot-side inlet of the methanol tower reboiler (E103); the hot-side condensate outlet of the methanol tower reboiler (E103) is connected to the top of the dehydration tower (T101) and the middle section of the methanol tower (T102); the middle section of the dehydration tower (T101)... It is connected to the hot-side inlet of the fusel oil cooler (E104), and the hot-side outlet of the fusel oil cooler (E104) is connected to the phase separation tank (V101); the oil phase outlet of the phase separation tank is connected to the hot-side inlet of the higher alcohol cooler (E114), and the water phase outlet is connected to the lower part of the dehydration tower (T101); the bottom of the dehydration tower (T101) is connected to the tube-side inlet of the dehydration tower reboiler (E102) and the hot-side inlet of the wastewater cooler (E113) respectively. The top of the methanol tower (T102) is connected to the methanol tower condenser (E105), and the condensate outlet of the methanol tower condenser (E105) is connected to the top of the methanol tower (T102) and the methanol collection pipeline, respectively. The bottom of the methanol tower (T102) is connected to the tube-side inlet of the methanol tower reboiler (E103) and the vaporization tank (V102), respectively, and the tube-side outlet of the methanol tower reboiler (E103) is connected to the bottom of the methanol tower (T102). The bottom of the vaporizer (V102) is connected to the tube-side inlet of the vaporizer reboiler (E106), and the tube-side outlet of the vaporizer reboiler (E106) is connected to the vaporizer (V102). The gas phase outlet at the top of the vaporizer is connected to the inlet of the membrane module (PU101). The permeate outlet of the membrane module (PU101) is connected to the shell-side inlet of the membrane module condenser (E108), and the shell-side condensate outlet of the membrane module condenser (E108) is connected to the phase separation tank. The tube-side outlet of the membrane module (PU101) is connected to the shell-side inlet of the ethanol tower No. 1 reboiler (E107), and the shell-side condensate outlet of the ethanol tower No. 1 reboiler (E107) is connected to the middle of the ethanol tower (T103). The top of the ethanol tower (T103) is connected to the shell side of the ethanol tower condenser (E110). The condensate outlet of the shell side of the ethanol tower condenser (E110) is connected to the top of the ethanol tower (T103) and the light component collection pipeline, respectively. The upper middle part of the ethanol tower is connected to the top of the stripping tower (T104). The bottom of the ethanol tower (T103) is connected to the tube side inlet of the ethanol tower No. 1 reboiler (E107), the tube side inlet of the ethanol tower No. 2 reboiler (E109), and the hot side inlet of the higher alcohol cooler (E114), respectively. The tube side outlets of the ethanol tower No. 1 reboiler (E107) and the tube side outlets of the ethanol tower No. 2 reboiler (E109) are both connected to the bottom of the ethanol tower (T103). The top of the stripping tower (T104) is connected to the upper middle part of the ethanol tower (T103); the bottom of the stripping tower (T104) is connected to the tube inlet of the stripping tower reboiler (E111) and the hot side inlet of the ethanol cooler (E112). The hot-side outlet of the ethanol cooler (E112) is connected to the ethanol product extraction pipeline; the hot-side outlet of the wastewater cooler (E113) is connected to the wastewater extraction pipeline; and the hot-side outlet of the higher alcohol cooler (E114) is connected to the higher alcohol extraction pipeline.
2. The apparatus according to the process method of claim 1, characterized in that: The membrane module (PU101) is a liquid phase dehydration membrane module. The outlet of the methanol tower bottom liquid is connected to the inlet of the liquid phase membrane module (PU101) tube side; the outlet of the liquid phase membrane module (PU101) tube side is connected to the feed port of the ethanol tower (T103).
3. The apparatus for the process according to claim 1, characterized in that: The vapor phase membrane module (PU101) is moved between the dehydration tower (T101) and the methanol tower (T102): the top of the dehydration tower (T101) is connected to both the tube-side inlet of the membrane module and the shell-side inlet of the methanol tower reboiler (E103); the tube-side outlet of the membrane module (PU101) is connected to the shell-side inlet of the vaporizer reboiler (E106), and the shell-side outlet of the vaporizer reboiler (E106) is connected to the feed inlet of the methanol tower (T102); the methanol tower (T102)... The reboiler is connected to the tube inlet of the methanol tower reboiler (E103), the tube inlet of the vaporizer reboiler (E106), and the feed inlet of the ethanol tower (T103). The tube outlet of the vaporizer reboiler (E106) is connected to the methanol tower (T102). The top of the methanol tower (T102) is connected to the shell inlet of the ethanol tower reboiler (E107). The condensate in the shell of the ethanol tower reboiler (E107) is connected to the top of the methanol tower (T102) and the methanol outlet pipeline.
4. The apparatus according to the process method of claim 1, characterized in that: The liquid phase membrane module (PU101) is moved between the dehydration tower (T101) and the methanol tower (T102): the top of the methanol tower reboiler (E103) is connected to the inlet of the membrane module and the top of the dehydration tower, respectively; the outlet of the membrane module (PU101) is connected to the feed inlet of the methanol tower (T102); the bottom of the methanol tower (T102) is connected to the inlet of the methanol tower reboiler (E103) and the feed inlet of the ethanol tower (T103), respectively; the top of the methanol tower (T102) is connected to the shell inlet of the ethanol tower reboiler (E107), and the condensate in the shell of the ethanol tower reboiler (E107) is connected to the top of the methanol tower (T102) and the methanol collection pipeline, respectively.
5. The apparatus for the process according to claim 1, characterized in that: The membrane module (PU101) is reduced and replaced with a dehydration tower (T101), a methanol tower (T102), an ethanol tower (T103), and a stripping tower (T104). The outlet of the methanol tower (T102) is connected to the inlet of the ethanol tower (T103).
6. The apparatus for the process according to claim 1, characterized in that: The stripping tower (T104) is reduced to a three-tower system consisting of a dehydration tower (T101), a methanol tower (T102), and an ethanol tower (T103). The side stream of the ethanol tower (T103) is connected to the hot-side inlet of the ethanol cooler (E112), and the ethanol product is collected from the side stream of the ethanol tower (T103). Alternatively, the condensate outlet of the shell side of the ethanol tower condenser (E110) is connected to the top of the ethanol tower (T103) and the ethanol collection pipeline, respectively, and the ethanol product is collected from the top of the ethanol tower.
7. The apparatus for the process according to claim 1, characterized in that: The stripping tower (T104) and the ethanol tower (T103) are combined into a single ethanol tower (T103) using a partitioned tower. The partitioned tower is equipped with vertical partitions that divide the ethanol tower (T103) into a feed side and an ethanol collection side. The ethanol side reboiler of the ethanol tower (T103) is connected to the tube inlet of the ethanol side reboiler (E115) and the hot side inlet of the ethanol cooler (E112), respectively. The tube outlet of the ethanol side reboiler (E115) is connected to the ethanol side of the ethanol tower (T103).
8. The apparatus for the process according to any one of claims 3 or 4, characterized in that: The fusel oil cooler (E104) and phase separation tank (V101) are reduced, and the shell-side condensate outlet of the membrane module condenser (E108) is connected to the lower part of the dehydration tower (T101); a steam reboiler (E116) is added to the bottom of the methanol tower (T102).
9. The apparatus for the process according to claim 1, characterized in that: Typical operating conditions for each tower are as follows: The operating pressure range at the top of the dehydration tower (T101) is 80–900 kPa; The operating pressure range at the top of the methanol tower (T102) is 30–600 kPa; The operating pressure range at the top of the ethanol tower (T103) is 20–300 kPa; The operating pressure range at the top of the stripping tower (T104) is 20–300 kPa.
10. The apparatus for the process according to claim 1, characterized in that: The membrane module (PU101) is replaced by a conventional molecular sieve adsorption bed. The molecular sieve uses two or more molecular sieve adsorption beds to switch between adsorption and desorption, thereby realizing the dehydration process of the material.