CN101274881A

CN101274881A - Energy-saving method for producing dimethy ether by boiler with residual heat

Info

Publication number: CN101274881A
Application number: CNA200810049795XA
Authority: CN
Inventors: 杨奇申; 李留记; 彭静亚
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-05-19
Filing date: 2008-05-19
Publication date: 2008-10-01

Abstract

The invention relates to a method for producing dimethyl ether by using a boiler which has waste heat and the method is energy saving and can effectively solve the problems of large energy consumption and high manufacturing cost during the production process of the dimethyl ether. The method comprises the steps that: after being preheated by a methanol preheater, methanol is sent into an evaporator and then into a heat exchanger after being evaporated and vaporized; under the temperature of 240 to 380 DEG C, the pressure of 0.3 to 1.3MPa and the catalysis of a modified alumina catalyst, the methanol is dehydrated to generate a crude dimethyl ether mixture; the mixture enters the heat exchanger to be cooled and then into a waste heat boiler; the heat is recycled, water is added to generate steam and the mixture is sent into the methanol preheater after being further cooled and treated in the waste heat boiler; after being cooled, the mixture is sent into a crude methyl ether condensator or directly enters a dimethyl ether rectifying column to rectify out dimethyl ether; residual liquid in the dimethyl ether rectifying column is sent into a methanol recovery tower to rectify and recycle the methanol in the residual liquid and the recycled methanol can be reused by the system. The production method of the invention is simple, scientific, energy saving and environment-friendly and has little investment, low cost and obvious economic and social benefits of popularization and application.

Description

Make the production method of dme with the boiler energy-saving of band waste heat

One, technical field

The present invention relates to chemical field, particularly a kind of boiler energy-saving with the band waste heat is made the production method of dme.

Two, background technology

Along with the in short supply and price increase of petroleum resources, going deep into of clean environment firendly theory as the clean fuel of diesel oil alternate resources---dme is widelyd popularize, and progressed into domestic fuel market and automobile fuel market.The production method of dme mainly comprises two step method and single stage method at present, two step method is produced the main outer heat supply of dme and can be made, energy input is big, the cost height, synthesis flow is long, and the working pressure height is difficult to effectively apply, and during the single stage method preparing dimethy ether, generate a part dme and will produce a part CO ₂, promptly have 1/3rd CO to be generated CO in process of production ₂, not only increased unstripped gas consumption, CO ₂Discharging consider it is disadvantageous from environmental angle, also be a kind of waste from conservation of resources, can develop a kind of dimethyl ether production method of energy-saving and environmental protection so?

Three, summary of the invention

At above-mentioned situation, the present invention's purpose just provides the production method that a kind of boiler energy-saving with the band waste heat is made dme, can solve effectively that to produce in the dme process energy consumption big, the problem that manufacturing cost is high, the technical scheme of its solution is: the methyl alcohol that with quality purity is 70-99.9% is after the methanol preheater preheating, send into vaporizer, behind the methyl alcohol carburation by evaporation, enter interchanger again, 240 ℃-380 ℃ of temperature, under pressure 0.3-1.3Mpa and the modified alumina catalyst catalysis, methanol dehydration generates thick dme mixture, mixture enters the interchanger cooling, enters waste heat boiler after the cooling, reclaims heat, add water generates steam, in the waste heat boiler further cooling sending into methanol preheater again after handling, send into thick methyl ether condenser after the cooling or directly enter the rectifying of dme rectifying tower and go out dme, raffinate is sent into methanol distillation column rectifying and is reclaimed in the raffinate methyl alcohol retrieval system and utilize in the dme rectifying tower.That the inventive method is produced is simple, science, energy-saving and environmental protection, less investment, and cost is low, and it is remarkable to apply economic and social benefit.

Four, description of drawings

Accompanying drawing is a process flow sheet of the present invention.

Five, embodiment

Below in conjunction with accompanying drawing the specific embodiment of the present invention is elaborated.

Provided by accompanying drawing, the present invention is realized by following steps:

With quality purity 70-99.9%, temperature is that 10 ℃ methyl alcohol is when methanol preheater 1 is preheating to more than 80 ℃, send into vaporizer 2, after ℃ vaporizing with steam heating to 170, send into interchanger 3, with from about the hot gas heat exchange to 200 of waste heat boiler 4 outlet ℃, send in the homogeneous temperature type dimethyl ether reactor 5,240 ℃-380 ℃ of temperature, under pressure 0.3-1.3Mpa and the modified alumina catalyst catalysis, methanol dehydration generates thick dme mixture, mixture is by weight percentage: dme 51%, methyl alcohol 21%, water 28%, go out reactor, send into interchanger 3 for about 300 ℃ in temperature, when cooling to 240 ℃ of left and right sides, be sent to waste heat boiler 4 again, add water, produce steam and recycle, when mixture drops to 180 ℃ of left and right sides, be sent to methanol preheater 1, continuing cooling handles, when cooling to 85 ℃ of left and right sides, send into thick dme condenser 6, when condensing to 50 ℃ of left and right sides, send into dme rectifying tower 7, it is 99.9% dme that rectifying goes out quality purity, or does not directly send into dme rectifying tower 7 by the dme condenser, and it is 99.9% dme that rectifying goes out quality purity, with the remaining dme that contains, methyl alcohol, the mixture of water, send into methanol distillation column 8, reclaim unconverted methyl alcohol, the refined methanol that reclaims through methanol distillation column 8 rectifying is Returning utilization again, contain methyl ether, after the rectifying water raffinate of first alcohol and water is cooled and handles, do the circulation make up water and use.

Being example by 100Kg methanol production dme, specifically be, with quality purity is 70-99.9%, shown in the methyl alcohol 100Kg[node (1) that temperature is 10 ℃] place methanol preheater 1, sending into vaporizer 2[when being preheated to more than 80 ℃ is sent into by node (2)], during with steam heating gasified methanol to 170 ℃ (± 5 ℃) left and right sides, be sent in the interchanger 3 and [send into] by node (3), with from (promptly ± 10 ℃) about the hot gas heat exchange to 200 of waste heat boiler 4 outlet ℃, [by node (4)] send into homogeneous temperature type dimethyl ether reactor 5,240 ℃-380 ℃ of temperature, after the catalysis of pressure 0.3-1.3Mpa and modified alumina catalyst, methanol dehydration generates thick dme mixture, the weight percent meter of mixture: dme 51%, methyl alcohol 21%, water 28%, [node (5) state when being cooled to 300 ℃, gas mixture composition is still dme 51%, methyl alcohol 21%, water 28%] send into interchanger 3, after heat exchange cools to 240 ℃ [node (6) mixture state is constant], send into waste heat boiler 4, add water, when continuing to cool to 180 ℃ of left and right sides [node (7) state], send into methanol preheater 1, continue cooling, during to 85 ℃ of left and right sides ([node (8) state] liquid-vapor mixture composition of ± 10 ℃ of this moments is still constant), send into thick dme condenser 6, [node (9) state becomes liquid mixture when condensing to below 50 ℃, its composition is formed still constant], be sent to dme rectifying tower 7, generating quality purity through rectifying tower rectifying is 99.9% dme 50.9Kg, 35 ℃ of liquid temperatures [node (10) state], raffinate after the rectifying contains dme 0.01Kg, methyl alcohol 21Kg, water 28Kg, 120 ℃ of temperature [node (11) state], send into methanol distillation column 8, reclaim unconverted methyl alcohol, the refined methanol that reclaims through methanol distillation column 8 rectifying retrieval system again utilizes again, refined methanol is 20.9Kg, 40 ℃ of temperature, purity is 99.9%[node (12) state], in the rectifying water raffinate that methanol distillation column rectifying produces, contain dme 0.1Kg, methyl alcohol 0.1Kg, water 28Kg, 130 ℃ of temperature [node (13) state] are done the circulation make up water after the processing that is cooled and are used.

From the above, the present invention utilizes the waste heat of being produced in the dme synthetic reaction process, be used for the dme rectifying of self again by the steam of waste heat boiler generation, can reduce outer significantly for steam consumption, save energy, reduce cost, reduce environmental pollution, according to test, from the heat of waste heat boiler recovery, dme per ton can be paid 0.5 ton of producing steam, be recycled, and unconverted methyl alcohol sends into methanol distillation column rectifying and utilize, make full use of resource, realize comprehensive utilization of energy, the huge of benefit do not expected, method advanced person, safety, efficiently, energy-conservation, invest little, cost is low, quality is good, non-environmental-pollution, be the innovation greatly of one on dme is produced, economic and social benefit is huge.

Claims

1, a kind of boiler energy-saving with the band waste heat is made the production method of dme, it is characterized in that, with quality purity 70-99.9%, temperature is that 10 ℃ methyl alcohol is when methanol preheater (1) is preheating to more than 80 ℃, send into vaporizer (2), after ℃ vaporizing with steam heating to 170, send into interchanger (3), with from about the hot gas heat exchange to 200 of waste heat boiler (4) outlet ℃, send in the homogeneous temperature type dimethyl ether reactor (5), 240 ℃-380 ℃ of temperature, under pressure 0.3-1.3Mpa and the modified alumina catalyst catalysis, methanol dehydration generates thick dme mixture, mixture is by weight percentage: dme 51%, methyl alcohol 21%, water 28%, go out reactor, send into interchanger (3) for about 300 ℃ in temperature, when cooling to 240 ℃ of left and right sides, be sent to waste heat boiler (4) again, add water, producing steam recycles, when mixture drops to 180 ℃ of left and right sides, be sent to methanol preheater (1), continuing cooling handles, when cooling to 85 ℃ of left and right sides, send into thick dme condenser (6), when condensing to 50 ℃ of left and right sides, send into dme rectifying tower (7), it is 99.9% dme that rectifying goes out quality purity, or does not directly send into dme rectifying tower (7) by the dme condenser, and it is 99.9% dme that rectifying goes out quality purity, with the remaining dme that contains, methyl alcohol, the mixture of water, send into methanol distillation column (8), reclaim unconverted methyl alcohol, the refined methanol that reclaims through methanol distillation column (8) rectifying is Returning utilization again, contain methyl ether, after the rectifying water raffinate of first alcohol and water is cooled and handles, do the circulation make up water and use.

2, boiler energy-saving with the band waste heat according to claim 1 is made the production method of dme, it is characterized in that, by 100Kg methanol production dme be, with quality purity is 70-99.9%, the methyl alcohol 100Kg that temperature is 10 ℃ places methanol preheater (1), when being preheated to more than 80 ℃, send into vaporizer (2), with steam heating gasified methanol to 170 ℃, during 5 ℃ of left and right sides, be sent in the interchanger (3), with from about the hot gas heat exchange to 200 of waste heat boiler (4) outlet ℃, send into homogeneous temperature type dimethyl ether reactor (5), 240 ℃-380 ℃ of temperature, after the catalysis of pressure 0.3-1.3Mpa and modified alumina catalyst, methanol dehydration generates thick dme mixture, the weight percent meter of mixture: dme 51%, methyl alcohol 21%, water 28%, when being cooled to 300 ℃, send into interchanger (3), after heat exchange cools to 240 ℃, send into waste heat boiler (4), add water, when continuing to cool to 180 ℃ of left and right sides, send into methanol preheater (1), continue cooling, during to 85 ℃ of left and right sides, send into thick dme condenser (6), condense to below 50 ℃, become liquid mixture, be sent to dme rectifying tower (7) again, generating quality purity through rectifying tower rectifying is 99.9% dme 50.9Kg, 35 ℃ of liquid temperatures, raffinate after the rectifying contains dme 0.01Kg, methyl alcohol 21Kg, water 28Kg, 120 ℃ of temperature, send into methanol distillation column (8), reclaim unconverted methyl alcohol, the refined methanol that reclaims through methanol distillation column (8) rectifying retrieval system again utilizes again, and refined methanol is 20.9Kg, 40 ℃ of temperature, purity is 99.9%, in the rectifying water raffinate that methanol distillation column rectifying produces, contains dme 0.1Kg, methyl alcohol 0.1Kg, water 28Kg, 130 ℃ of temperature are done the circulation make up water after the processing that is cooled and are used.