CN109762611A

CN109762611A - A method of using waste water water-coal-slurry and passing through water-coal-slurry methanol

Info

Publication number: CN109762611A
Application number: CN201910089206.9A
Authority: CN
Inventors: 吕彬峰; 李正平; 邱一鑫; 蒋贤武; 冯振涵
Original assignee: Zhejiang Tianlu Environmental Technology Co Ltd
Current assignee: Zhejiang Tianlu Environmental Technology Co Ltd
Priority date: 2019-01-30
Filing date: 2019-01-30
Publication date: 2019-05-17

Abstract

The present invention provides a kind of methods for preparing methanol using low-order coal multipath, low-order coal dried by stoving process after low-order coal and exhaust gas, low-order coal after drying issues angerization reduction reaction in anaerobic or micro-oxygen conditions and obtains upgraded coal and rich gas, and a kind of approach is the raw material that synthesizing methanol is prepared using rich gas as raw material；Another way is that the moisture recycled in exhaust gas and rich gas first prepares water-coal-slurry, recycles raw material of the water-coal-slurry as methanol-fueled CLC；It is that approach prepares methanol that another approach, which is using upgrading coal gasification,.The present invention prepares methanol using number of ways, impurity in the methanol of preparation is few, low in raw material price, production cost is low, and make full use of the substances such as waste water in entire technical process, waste utilization economizes on resources, and to solving, existing low order moisture in coal recycling is insufficient and pollution environment has great importance.

Description

A method of using waste water water-coal-slurry and passing through water-coal-slurry methanol

Technical field

The present invention relates to coal substance clean utilization technical fields more particularly to a kind of utilization low-order coal multipath to prepare methanol Method.

Background technique

China is the country of a rich coal, oil-poor, few gas, and consumption of coal accounts for 60% or more of non-renewable energy consumption figure, Which dictates that the energy resource structure based on coal is difficult to change within the quite a long time.From explored coal mine quality It sees, low-order coal proportion is very big in coal in China, thus low-order coal production high-quality chemical industry in rationally and efficiently utilizing Product is particularly important.In recent years, the continuous development of the technologies such as coal gasification, pyrolysis of coal, gas purification and coal gas separation, It utilizes the clean and effective of middle low-order coal and has obtained more and more attention.

Methanol is basic Organic Chemicals and solvent, and is chemical products, its purposes in basic organic chemical industry It is only second to ethylene, propylene and benzene etc..Methanol has very important status and extremely extensive purposes in Chemical Manufacture, main It is used to manufacture a variety of organic products such as formaldehyde, acetic acid, chloromethanes, first ammonia, dimethyl sulfate, alkene and pesticide, medicine One of important source material.The deep processed product of methanol is up to more than 120 kinds at present, be widely used in chemical industry, light industry, communications and transportation, The industries such as medicine, weaving.

Drying is that low-order coal is former as boiler oil, gasified raw material, direct liquefaction raw material, pyrolysis feed or other deep processings The first step of material.Drying is both the needs for meeting downstream processing requirement, and reduces entire project energy consumption and downstream unit The needs of investment.What is generated in drying process is directly discharged into atmosphere comprising exhaust gas such as a large amount of vapor and coal dust etc., can aggravate Environmental pollution, therefore the coal dust of the generation effectively in recycling drying process and moisture have important practical significance.In low-order coal Moisture be generally divided into Free water and combine water, and it is dry be typically only capable to remove most Free water in low-order coal, be very difficult to Except the combination water in low-order coal, most of Free water that usual drying process drying is removed is easy the recycling that is condensed.But The Efficient Conversion Land use systems of usual low-order coal is are pyrolyzed after drying, still containing a large amount of in the high-temperature gas after pyrolysis Vapor, the content of this part water also should not be underestimated.However, it is contemplated that water content is higher in low-order coal, and low in richness production The regional water of rank coal is often of great rarity；If can effectively recycle valuable water resource in ground low-order coal simultaneously and dry Coal dust in journey, waste utilization prepares water-coal-slurry, then by the standby conversion gas of cool water mixture burning vaporizing system, is prepared again using conversion gas Methanol, to solving, existing low order moisture in coal recycling is insufficient and pollution environment has great importance.

Methanol is prepared using good coal such as anthracite, although the yield of methanol is higher, production cost compared with It is high.Much the poor quality of middle low-order coal, ash content are high, water content is high in China, methanol are prepared using low-order coal, usually by low order Crude coal gas and upgraded coal are obtained after pyrolysis of coal, general pyrolysis is carried out under conditions of having a large amount of oxygen (or air), heat A part of low-order coal will be used for heat supply in oxygen reaction and produce a large amount of CO when solution₂.Due to CO₂It cannot burn, belong to Invalid gas, and because of oxy combustion, nitrogen content is excessively high in crude coal gas, reduces H in crude coal gas₂It is close with CO energy Degree reduces crude calorific value of gas, and other than return combustion, the pyrolysis crude coal gas difficulty of output has other economic values.And coal gas Its molecule cannot all be interrupted life the biggest problems are that underuse the chemical constituent contained in coal by change process Produce CO, H₂, then chemically synthetizing methanol is carried out, and the reduction of low order coal gasification, reforming technique and methanol synthesis technology then can be maximum Limit remains the chemical constituent in coal in the form of methanol.In addition, part of coal will be reacted in oxygen when pyrolysis And consume, cause the amount of upgraded coal less, finally the amount of the methanol made from upgraded coal approach is few even cannot get upgrading Coal greatly wastes the effective coal resource in low-order coal.In addition, crude coal gas contains a large amount of vapor, however, examining Consider that water content in low-order coal is higher, and is often of great rarity in the rich regional water for producing low-order coal；If can simultaneously effectively Valuable water resource etc., waste utilization prepare water-coal-slurry in recycling ground low-order coal, then by cool water mixture burning vaporizing system for conversion Gas prepares methanol using conversion gas again, and to solving, existing low order moisture in coal recycling is insufficient and pollution environment has important meaning Justice.

Summary of the invention

In view of this, utilizing low-order coal multipath in view of the deficiencies of the prior art, it is an object of the present invention to provide a kind of The method for preparing methanol is restored by gasifying after drying low-order coal, make full use of volatile matter in low-order coal, coal substance with And the water-coal-slurry of waste water preparation, as the raw material of methanol-fueled CLC, approach is more, and the impurity in the methanol of preparation is few, and quality is high, mentions The high utilization rate of low-order coal.

In order to solve the above technical problems, the present invention provides the following technical scheme that

A method of methanol being prepared using low-order coal multipath, is comprised the following steps that:

(1) low-order coal and exhaust gas after low-order coal drying process is dried, the exhaust gas pass through the first dedusting Technique obtains coal dust；

(2) low-order coal after drying described in step (1) is handled to obtain rich gas and upgraded coal by the reducing process that gasifies, The gasification reducing process is the chemical reaction process heated under anaerobic or micro-oxygen conditions to the low-order coal after drying；

(3) rich gas and waste water after being purified step (2) described rich gas by the first purification process；

(4) purified rich gas described in step (3) passes sequentially through sulfur removal technology and the first compression process handles to obtain weight Turn over unstripped gas；The reforming unstripped gas is obtained by reforming process comprising CO, CO₂And H₂First turn Change gas；

(5) water coal is obtained after mixing coal dust described in waste water described in step (3), step (1) with slurries additive agent Slurry, by the water-coal-slurry and O₂It handles to obtain comprising CO, CO by coal-water slurry gasification₂And H₂The second water-gas, institute It states after the second water-gas is handled by the second purification process and obtains the second conversion gas；

(6) by upgraded coal described in step (2) by with H₂O and O₂Reaction preparation includes CO, CO₂And H₂Third water coal Gas obtains third and converts gas after handling the third water-gas by third purification process；

(7) third in the second conversion gas in the first conversion gas described in step (4), step (5) and step (6) is converted At least one of gas is by being selected from one or more of decarburization mend carbon technology, shift conversion technique and benefit hydrogen technique and mixing Methyl methanol syngas is obtained, the hydrogen-carbon ratio R value of the methyl methanol syngas is 2.05~2.1；

(8), methyl methanol syngas described in step (7) passes sequentially through the second compression process, methanol synthesizing process obtains thick first Pure and mild methanol purge gas, the crude carbinol obtain product methanol by methanol rectification technique.

Preferably using the low-order coal of powdery as raw material in the present invention, convenient for improving the efficiency of drying, drying generally can only Most Free water in low-order coal is removed, and cannot generally remove the combination water in low-order coal, therefore, low-order coal passes through baking Low-order coal and exhaust gas after being dried after dry process, the low-order coal after gained drying still contain a certain amount of moisture, The moisture of this some residual can gasify in subsequent gasification reducing process and become vapor.The meeting simultaneously during drying The low-order coal of some small grain size is entered in exhaust gas in the form of fugitive dust, this part fugitive dust is mainly coal dust, raw material low order The granularity of coal is smaller, and the coal dust in exhaust gas is more, and exhaust gas direct emission not only polluted environment, wastes coal resource, therefore The first coal dust in exhaust gas after capturing recycling stoving process by the first dust collecting process has important economic value.Generally Pass through in the first dust collecting process exhaust gas recycling 95% or more coal dust.

Low-order coal after drying enters gasification reducing process and reacts to obtain the rich gas of high temperature.Wherein, gasification reduction work Skill is the chemical reaction process heated under anaerobic or micro-oxygen conditions to the low-order coal after drying.Low-order coal after drying Into gasification reducing process, under the heating of the heat mediums such as flue gas, it is not necessary that other objects such as additive are added in reaction process Matter, temperature are generally 350 DEG C -800 DEG C, and the process of complex chemical reaction occurs under pressure≤30Kpa, obtain solid carbon and The rich gas of high temperature, wherein solid carbon is upgraded coal, the volatile matter 8-15wt% in upgraded coal.The rich gas of high temperature be comprising CO、H₂、CO₂, hydro carbons, coal tar, naphthalene, halide, dust and sulfur-containing compound etc. more foreign gases.

The source of oxygen is mainly in the following several ways in the anaerobic or micro- oxygen environment that reducing process uses that gasify: (1), raw material Gap inside low-order coal, the air of the gap entrainment between material and material；(2) from gasification reducing process feed inlet, go out Material mouth etc. reveals mixed a small amount of air；(3), coal is accounted for hereinafter, can slightly be passed through in gasification reducing process in explosion limit value The O of charcoal mass percent 5%₂Or (air), further preferably it is passed through the O for accounting for Coal Quality percentage 3%₂Or it is (empty Gas), be conducive to temperature, the slagging prevention etc. that improve gasification reduction reaction, and ensure that entire gasification reducing process is anti-simultaneously The security and stability answered；It is preferred that the low-order coal after drying carries out gasification reduction reaction in oxygen-free environment, it is low after avoiding drying With oxygen combustion reaction occurs for rank coal in entering gasification reducing process reaction process, generates a large amount of aphlogistic CO₂, from And guarantee CO in the rich gas of obtained high temperature₂Deng volume basis it is smaller, be conducive to the subsequent conversion for preparing high-energy density Gas, and processing step is few, it is simple to operation, so that reaction can carry out safely.

The obtained rich gas of gasification reducing process enter the first purification process so as to remove a large amount of dust, coal tar, naphthalene and The impurity such as vapor be purified after rich gas.Rich gas during purification can rich producing coal tar and waste water, waste water can be used as The water resource of water-coal-slurry is prepared, coal tar can be used as stored energy source.Purified rich gas passes sequentially through sulfur removal technology and the first pressure Contracting technique, which removes sulfide etc., makes the harmful substance of catalyst poisoning to obtain reforming unstripped gas.Reforming raw material Two some hydrocarbon therein is converted to CO and H by reforming technique by gas₂, to obtain the first conversion gas.

Waste water, slurries additive agent and the coal dust recycled from the exhaust gas after drying will be obtained in above-mentioned first purification process It is mixed and made into flowable solution, water-coal-slurry can be obtained；By water-coal-slurry and O₂It is wrapped together by coal-water slurry gasification Containing CO and H₂The second water-gas, the second water-gas, which passes through again after the second purification process removes the impurity such as dust, obtains second turn Change gas.Finally recycle decarburization mend carbon technology by first convert gas, in the second conversion gas and third conversion at least one of gas By being selected from one of decarburization mend carbon technology, shift conversion technique or hydrogenation technique or several techniques and being mixed to get hydrogen The methyl methanol syngas that carbon ratio R value is 2.05~2.1；Methyl methanol syngas passes sequentially through the second compression process, methanol synthesizing process obtains To crude carbinol and methanol purge gas, crude carbinol obtains product methanol by methanol rectification technique.

Preferably, sulfur removal technology described in step (4) includes fine desulfurizing technology and thick sulfur removal technology, the purified richness Gas passes sequentially through thick sulfur removal technology, the first compression process and fine desulfurizing technology and handles to obtain reforming unstripped gas.Thick desulfurization work The cooperation of skill, fine desulfurizing technology, so that the sulfur-bearing total amount of purified rich gas is preferably minimized as far as possible.

Preferably, the first purification process described in step (3) includes dust collecting process and detar technique.

Change the reaction equation of conversion process are as follows:The percent by volume of CO can be reduced, H is increased₂ Percent by volume.In reforming technical process, there is H in reforming unstripped gas₂In the presence of O (vapor), With certain side reaction, side reaction is mainly CO and H₂O (vapor) shift conversion H₂Reaction.

It is preferred, therefore, that the shift conversion technique is during reforming unstripped gas to methyl methanol syngas by CO By with H₂O response transform is converted into H₂。

Preferably, third in the second conversion gas in the first conversion gas described in step (4), step (5) and step (6) is turned At least one of change gas first passes through shift conversion technique and obtains the first conversion gas, the second conversion gas and third conversion gas, described At least one of first conversion gas, the second conversion gas and third conversion gas pass through decarburization mend carbon technology and are mixed to get methanol conjunction At gas.The hydrogen-carbon ratio of each conversion gas is all less likely to do well boundary between 2.05-2.1, but can choose wherein one Kind, two kinds or three kinds of conversion gas first increase H by shift conversion technique₂Percent by volume, in order to obtain more hydrogen Gas remixes and obtains methyl methanol syngas by decarburization mend carbon technology adjustment hydrogen-carbon ratio.Hardly aqueous steaming in first conversion gas Gas, the second conversion gas and third conversion gas wherein contain vapor, and the especially second conversion gas is the coal water slurry gasification by liquid Gained, containing a large amount of remaining vapor after the gasification in water-coal-slurry, this part vapor can be used as the original of shift conversion reaction Material, it is therefore preferable that the second conversion gas described in step (4) obtains the second conversion gas by shift conversion technique, described second becomes Ventilation converts at least one of third conversion gas described in gas, step (6) in step (5) second and passes through decarburization mend carbon technology And it is mixed to get methyl methanol syngas.

Preferably, decarburization mend carbon technology described in step (7) is the first conversion gas, the second conversion gas and third conversion When one of gas or several hydrogen-carbon ratio R values are greater than 2.1, it is passed through CO₂, so that R value is adjusted to 2.05-2.1；Described When one of one conversion gas, the second conversion gas and third conversion gasification or several hydrogen-carbon ratio R values are less than 2.05, removing CO₂, so that R value is adjusted to 2.05-2.1.Decarburization mend carbon technology includes decarbonization process and mend carbon technology, that is, removes and supplement CO₂, Successively come achieve the purpose that adjust gas hydrogen-carbon ratio.

Preferably, it is that H is added during reforming gas to methyl methanol syngas that hydrogen technique is mended in step (4)₂Technique. The H of supplement₂What but the external world was directly bought, it is also possible to the H recycled from subsequent methanol purge gas₂, the R value of the first conversion gas If too small, H₂It can directly be supplemented into the first conversion gas.The H that can also will be recycled from subsequent methanol purge gas₂As In circulating air supplement machine in the second compression process.

Preferably, the granularity of coal dust described in step (1) is less than 1mm.Water-coal-slurry preparation first has to carry out coal substance thin Mill, the coal dust in exhaust gas generated during stoving process due to raw material of the present invention, can through the first dust collecting process In exhaust gas 95% or more coal dust is recycled, coal powder size is generally less than 3mm, and coal dust of the preferred size less than 1mm is as subsequent system The raw material for making water-coal-slurry, by coal dust, with waste water, additive mixing can be obtained water-coal-slurry without milled processed, save technique Step, and the cost of coal pulverizer is greatly reduced, improve the service life of coal pulverizer.Still further preferably, fine coal partial size ≤ 50 μm of coal dust.

Preferably, the reaction temperature of gasification reducing process described in step (2) is 350-800 DEG C.At this temperature, it dries The volatile matter in low-order coal afterwards is escaped from low-order coal, so that the rich gas of high temperature is obtained, it is remaining solid after the reduction reaction that gasifies Body residue is the upgraded coal with temperature, and the volatile matter content in upgraded coal is 8-15wt%.Wherein, gasification reducing process can be with For level-one, or multistage.When using level-one gasification reducing process, primarily to the rich gas of most of high temperature is obtained, The height of temperature directly affects the temperature of subsequent gas production, the yield of upgraded coal and level-one upgraded coal；It is gone back when using multistage gasification When original process, multistage gasification reducing process main function is the solids that can not gasify in upper level gasification reducing process Matter (including the fine coal after gasification, solid impurity etc.), a certain amount of similar pitch etc. that can not gasify within certain residence time Higher boiling grease continues gasification and the residence time short has little time to be precipitated or phenolic compound, fragrant hydrocarbonylation is not achieved in temperature The polycondensation reaction condition of object etc. is closed, gasification that the reaction was continued is conducive to improve gas yield.

Reforming unstripped gas is that gas each component is not in reforming unstripped gas through the reforming technique of some hydrocarbon It is directly that some hydrocarbon is reforming for CO and H through separating₂Hydrocarbon conversion technique because reforming purpose only be The hydrocarbon conversion is generated into CO and H₂, and itself contained some CO and H in reforming unstripped gas₂, there is no need to by hydrocarbon Class separates hydro carbons from reforming unstripped gas and carries out the reforming of hydro carbons again, the first conversion gas is obtained, using in this way Operation save processing step, high financial profit.

Reforming technique is converted selected from steam reformation, steam pure oxygen is reforming and pure oxygen is reforming one such Or it is several.Steam reformation, which converts, steam purity oxygen is reforming is required to catalyst, and the catalyst of reforming technique is mostly Loaded catalyst, active component are mainly that Ni, Co, Fe, Cu etc. be nonmetallic and the noble metals such as Rh, Ru, Pt.Reforming one As need heat supply, can be by the way of direct heating or indirect heating.Reforming steam purity oxygen is using pure oxygen (oxygen) and a part of hydrocarbon fuel direct heating, makes reaction temperature reach 850-1300 DEG C, under the effect of the catalyst, Some hydrocarbon in reforming unstripped gas is reacted with vapor generates CO and H₂；Extraneous heat supply is used when steam reformation converts, So that temperature is reached 850-1200 DEG C, makes some hydrocarbon and vapor in reforming unstripped gas under the effect of the catalyst Reaction generates CO and H₂；The key reaction mechanism of two methods are as follows:

(1)CmHn+mH₂O=mCO+1/2 (n+2m) H₂Main reaction, the endothermic reaction

(2)Side reaction, the endothermic reaction

With CH₄For, key reaction equation CH₄+H₂O→CO+3H₂, the H of generation₂Molar ratio with CO is 3:1, than Example is larger, and to preparing, reforming gas is highly beneficial.

Pure oxygen is reforming for pure oxygen to be passed through in reforming unstripped gas, key reaction mechanism are as follows: CH₄+1/2O₂→CO+ 2H₂, the H of generation₂Molar ratio with CO is 2:1, is conducive to preparation the first conversion gas.Other hydro carbons and methane and O in addition to methane₂ Reaction mechanism it is similar.

It is preferred, therefore, that reforming unstripped gas described in step (4) is reforming original through reforming process Expect that gas each component is without isolation in gas, directly by some hydrocarbon in the reforming unstripped gas it is reforming for CO and H₂Reforming technique.Preferably, reforming technique described in step (4) includes pure including steam reformation conversion, steam Oxygen is reforming and pure oxygen is reforming.

Preferably, the pressure 40-50kg of the second compression process described in step (8), temperature are 200-350 DEG C.Second pressure Contracting technique be in order to adjustment methyl methanol syngas the conditions such as pressure and temperature, be conducive to carry out methanol-fueled CLC under low pressure Reaction.

Based on above technical scheme, method in the present invention, by being waved gasification reduction in the low-order coal after drying CO and H needed for the reforming acquisition methanol-fueled CLC raw materials such as hair point, then hydro carbons in will volatilize point₂, to prepare methanol, fill Divide the volatile matter efficiently utilized in low-order coal；By being prepared gasification reduction acquisition upgraded coal in low-order coal is raw material The coal substance in low-order coal is utilized in methanol；It is used in addition, the present invention effectively recycles moisture and coal dust in low-order coal etc. Water-coal-slurry is made, waste utilization economizes on resources, and useless water reuse solves the problems, such as discharged wastewater met the national standard difficulty, coal dust Recycling solves problem of environmental pollution；Methanol contaminant prepared by the above number of ways is few, and quality is high, substantially increases low The utilization rate of rank coal meets the coal high-efficiency clean utilization that country advocates energetically.

Detailed description of the invention

It, below will be in embodiment in order to illustrate more clearly of embodiment in the present invention or technical solution in the prior art Required attached drawing is briefly described, it should be apparent that, the accompanying drawings in the following description is only one recorded in the present invention A little embodiments are also possible to obtain other drawings based on these drawings for those of ordinary skill in the art.

Fig. 1 is a kind of the first flow diagram of method that methanol is prepared using low-order coal multipath；

Fig. 2 is a kind of second of flow diagram of method that methanol is prepared using low-order coal multipath.

Specific embodiment

Next combined with specific embodiments below invention is further explained, but does not limit the invention to these tools Body embodiment.One skilled in the art would recognize that present invention encompasses may include in Claims scope All alternatives, improvement project and equivalent scheme.

In the present invention, if not refering in particular to, used raw material and equipment etc. are commercially available or commonly used in the art. Method in following embodiments is unless otherwise instructed the conventional method of this field.Term " first ", " in the present invention Two " etc. are only used for distinguishing description, are not understood to indicate or imply relative importance.

As shown in Figs. 1-2, the invention discloses a kind of methods for preparing methanol using low-order coal multipath, should include following Processing step；

A method of methanol is prepared using low-order coal multipath, it is characterised in that: is comprised the following steps that:

(8) methyl methanol syngas described in step (7) passes sequentially through the second compression process, methanol synthesizing process obtains crude carbinol And methanol purge gas, the crude carbinol obtain product methanol by methanol rectification technique.

Volatile matter content is generally 20%-55% in low-order coal, and the content of tar is 3%-15% or so, and fixed carbon contains Amount is 30%-60%, the content of water is 10%-40%, remaining as dust and other impurities.The degree of coalification of low-order coal is low, but Contain petroleum resources abundant, the volatile matter being rich in low-order coal is highly beneficial to synthesis gas is extracted.

Raw material low-order coal of the invention can be fine coal and be also possible to lump coal, when low-order coal uses lump coal, to bulk excessively Coal can be by broken, screening process to obtain the lesser fine coal of granularity.It is preferred that using fine coal as raw material, be on the one hand because It no longer needs to for fine coal through broken, screening process, saves processing step, heating surface area is big when drying, and drying efficiency is high, another party Face is that fine coal is cheap with respect to lump coal.It is preferred that being less than the fine coal of 20mm using granularity, still further preferably it is less than using granularity The fine coal of 6mm.

Drying can only generally remove most Free water in low-order coal, and cannot remove the combination water in low-order coal, because This, low-order coal by stoving process handle after dry after low-order coal and exhaust gas, gained dry after low-order coal still contain There is a certain amount of moisture, the moisture of this some residual can gasify in subsequent gasification reducing process becomes vapor.If low order Contain a large amount of moisture in coal, heat consumption is big during will lead to gasification reduction reaction, and therefore, technical solution of the present invention is first Choosing is handled the portion of water first removed in low-order coal by stoving process to low-order coal.The drying medium of stoving process It can be flue gas or vapor, drying can be divided into directly drying and indirect drying.When using flue gas as medium is dried, though Right flue gas is highest with the efficiency for the drying that low-order coal directly contacts, but flue gas is used to want strict control when being dried The percent by volume of oxygen is in explosion limit hereinafter, to prevent detonation, the efficiency of flue gas indirect drying in stoving process environment It is unsatisfactory, therefore for production safety and drying efficiency, preferably vapor is dried.Vapor, which is directly dried, to be easy to be possible to Cause vapor to be mixed into provide with the consumption in low-order coal, not only causing reaction coal resource, reduces drying efficiency, therefore Using the drying mode of vapor indirect drying low-order coal, to prevent the moisture in water steam from entering in low-order coal.In addition, drying If water vapour pressure is excessive during dry, vapor bring temperature is excessively high to be easy to cause during the drying process, in low-order coal Part volatile matter can escape, and the evolution of one side volatile matter can bring security risk, on the other hand will affect subsequent gasification The gas production of reducing process, thus in drying course dry steam pressure be not easy it is excessive, with guarantee both can guarantee drying effect, It can guarantee that the volatile matter in low-order coal is not gasified again.It is preferred, therefore, that stoving process uses water vapour indirect drying, water The pressure of steam is 0.3-1.5Mpa, and the temperature of water vapour is 105-250 DEG C, not only prevents the O in external air₂It is mixed Enter to consume coal substance, and can maximumlly reduce the moisture content in low-order coal under this process condition, it might even be possible to so that 7wt% is reduced to hereinafter, most moisture is adjoint at this time from the water content in the low-order coal that the discharge port of stoving process is discharged The fugitive dusts such as coal dust escaped from low-order coal, and as water vapor into the exhaust gas generated after drying, stoving process Outlet mass temperatures be 50-150 DEG C；Still further preferably, when the pressure of vapor is 0.6-1.2Mpa, the temperature of vapor When degree is 120-200 DEG C, after drying the moisture content of low-order coal will decrease to 6wt% hereinafter, stoving process outlet mass temperatures It is 80 DEG C -130 DEG C.

Stoving process of the invention can be level-one, or it is multistage, because if low-order coal after level-one stoving process Moisture content still reach to the requirement less than technique, can be continued using multistage dry such as second level drying, three-level stoving process into one Drying is walked, until the moisture content of low-order coal meets process conditions after drying.In addition, multistage stoving process can connect and set Setting can also be arranged in parallel, and can reinforce drying effect when connecting using multistage stoving process, can increase drying work when in parallel The treating capacity of skill, therefore according to the demand of actual production technique is series connection or in parallel or in series simultaneously to multistage stoving process In conjunction with when design, can be adjusted according to the actual situation, as long as identical technical effect can be reached, specifically, than Such as, when the inlet amount of stoving process is in terms of the low-order coal of 20-30t/h, level-one steam drying technique can be used；Work as stoving process Inlet amount in terms of the low order of 50-70t/h, second steam stoving process can be used, in this way it is more economical rationally.

Exhaust gas in drying course mainly includes the low-order coal of small grain size and the vapor that drying is removed, raw material low-order coal Granularity is smaller, and the coal dust in exhaust gas is more, and exhaust gas direct emission not only polluted environment, wastes coal resource, therefore pass through The coal dust in exhaust gas after first dust collecting process recycling stoving process has important economic value.It can through the first dust collecting process In exhaust gas 95% or more coal dust, referred to herein as coal dust are recycled, coal powder size is generally less than 3mm, and preferred size is less than 1mm's Coal dust improves grinding as the raw material of subsequent production water-coal-slurry to reduce the grinding technics to large particulate matter in water-coal-slurry The service life and efficiency of machine.

Low-order coal after being dried by stoving process enters gasification reducing process and is reacted, in order to advanced optimize work Skill, low-order coal after the drying can also add gasification feeding process before entering gasification reducing process, so as to low after drying Rank coal rapidly enters gasification reducing process, increases the surface area of material, is conducive to accelerate gasification reduction reaction.

Wherein, gasification reducing process is that the chemistry that is heated under anaerobic or micro-oxygen conditions to the low-order coal after drying is anti- Answer technique.Low-order coal after drying enters gasification reducing process, under the heating of the heat mediums such as flue gas, nothing in reaction process Other substances such as additive need to be added, temperature is generally 350 DEG C -800 DEG C, complex chemical reaction occurs under pressure≤30Kpa Process obtains the rich gas of solid carbon and high temperature, wherein solid carbon is upgraded coal, the volatile matter 8- in upgraded coal 15wt%.The rich gas of high temperature is to include CO, H₂、CO₂, hydro carbons, coal tar, naphthalene, halide, dust and sulfur-containing compound etc. it is more Foreign gas.

Wherein, the source of gasification reducing process uses anaerobic or micro- oxygen environment oxygen is mainly in the following several ways: (1), Gap inside raw material low-order coal, the air of the gap entrainment between material and material, the O in the air of this part₂Gasifying It is reacted immediately with coal in the environment of reducing process high temperature and generates CO₂Or CO；(2) from the feed inlet of gasification reducing process, discharging The mixed a small amount of air of the leakage such as mouth, the oxygen of this partial air, the micro O in this part₂In gasification reducing process high temperature It is reacted immediately with coal under environment and generates CO₂Or CO；(3), in explosion limit value hereinafter, can slightly lead in gasification reducing process Enter to account for the O of Coal Quality percentage 5%₂Or (air), 1. this operation, which has the advantage that, can be improved gasification reduction work Temperature and capacity usage ratio in skill；2. improving the conversion ratio of charcoal；3. preventing coal coking；4. a small amount of O₂It is endless with low-order coal Full burning produces more CO, brings more synthesis gas to be subsequent.Since gasification reducing process internal temperature is higher, The a small amount of O being passed through₂Moment can occur oxidation reaction (including combustion reaction), and the burning point of many combustibles is all anti-in gasification reduction Below the reaction temperature answered.Because CO mixes with air explosion limit 12%~74.2%；H₂Explosion value is 4%-75%.O₂Duty gas Ratio is 21%.The explosion limit upper value of pure oxygen is 6% or so after conversion.By theoretical calculation, the coal of 100kg can be generated about 80Nm³CO and H₂.So being passed through the O for accounting for Coal Quality percentage 5%₂It is safe；Still further preferably, it is passed through and accounts for coal The O of charcoal mass percent 3%₂, with the security and stability for the reducing process reaction that ensures entirely to gasify.But when gasification reduction is anti- When the temperature answered meets technique requirement, it can not also be passed through oxygen, the low-order coal after preferably drying gasifies in oxygen-free environment Reduction reaction, so that reaction can carry out safely.

Wherein, gasification reducing process can be level-one, or multistage.It is main when using level-one gasification reducing process If the rich gas of most of high temperature, the height of temperature directly affect subsequent gas production, the yield of upgraded coal and level-one in order to obtain The temperature of upgraded coal, the reaction temperature for the reducing process that gasifies are 350 DEG C -800 DEG C, and the volatile matter content in upgraded coal is 8- 15wt%, further preferably, the reaction temperature for the reducing process that gasifies are 400-750 DEG C；Still further preferably 450-700 DEG C.When When using multistage gasification reducing process, multistage gasification reducing process main function is the nothing in upper level gasification reducing process Method gasification solid matter (including gasification after fine coal, solid impurity etc.), it is a certain amount of can not within certain residence time gas The higher boilings grease such as similar pitch changed continues gasification and the residence time short has little time precipitation or phenol generalization is not achieved in temperature The polycondensation reaction condition of object, arene compound etc. is closed, gasification that the reaction was continued is conducive to improve gas yield and upgraded coal Quality.The unit price of upgraded coal is generally 500-600 member/T, and the upgraded coal after gasification reduction can be used for selling.

Other than the temperature of guarantee gasification reducing process is reasonable, while it must also guarantee certain in gasification reducing process stop The time is stayed, the residence time is too short, and volatile matter also not evolution gasification completely while influencing gas yield, more influences upgrading The quality of coal；Residence time is too long, although product is guaranteed, yield is not caught up with, so keeping a reasonable gasification The reduction reaction residence time is most important to product yield and quality.It is general to gasify since the kind of raw material low-order coal is different The residence time of material is 30min-4h in reducing process.

Preferably using two-stage gasification reducing process in the present invention, the material after stoving process drying is introduced into level-one gasification also Original process enter back into second level gasification reducing process, and the low-order coal after drying is introduced into level-one gasification reducing process and obtains level-one gas Body and level-one solid, level-one solid, which enters back into second level gasification reducing process, to be continued gasification and obtains secondary gas and second level solid, and two Grade solid is upgraded coal；The feeding temperature of level-one gasification reducing process is 80 DEG C -120 DEG C, and air outlet temperature is 180 DEG C -550 DEG C, reaction temperature is 450 DEG C -650 DEG C, and drop temperature is 350 DEG C -600 DEG C；The charging temperature of the second level gasification reducing process Degree be 350 DEG C -600 DEG C, drop temperature be 450 DEG C -750 DEG C, reaction temperature be 550 DEG C -800 DEG C, air outlet temperature be 450 DEG C - 700℃.When using two-stage gasification reducing process, primarily to most of volatile is made to be gasified totally, it can obtain big The gas of amount can obtain the lower upgraded coal of volatile matter again, and wherein the volatile matter content in upgraded coal is 3-8wt%.

The rich gas of gasification reducing process preparation can be using a portion as fuel, and for example, stoving process is either subsequent Reforming technique provide heat, realize heat supply oneself it is self-sustaining, without using extraneous fuel heat supply.

The rich gas of high temperature obtained from gasification reducing process enter the first purification process with remove solid dirt, tar, naphthalene, Unsaturated hydro carbons and halide etc. are can be obtained purified rich gas.

The rich gas of high temperature that gasification reducing process obtains enters the first purification process so as to the rich gas after being purified.First Purification process includes dust collecting process and detar technique etc..Rich gas is successively wrapped through dust collecting process and detar process Containing CO, H₂With the purified rich gas of hydro carbons.Contain a large amount of dust, coal tar, vapor, sulfur-bearing chemical combination in the rich gas of high temperature Object etc.；First with dedustings such as dust-extraction units, prevent the temperature of the rich gas in dust removal process from reducing, coal tar and vapor etc. are cold It congeals into liquid and adheres to a large amount of dusts and cause subsequent technique line clogging, dust removing effects is caused to decline；It should be containing big in rich gas The substance that amount naphthalene and tar etc. are easily coagulated or easily crystallized will cause damages to subsequent handling if these substances not removed as far as possible Even jeopardize the safety of whole device.Therefore, the tar in rich gas is taken off to≤1mg/Nm using detar technique³, such as adopt With cooling tower, the substances such as a large amount of vapor and naphthalene can also be condensed while cooling down the gaseous coal tar in rich gas, it is cooling The oil water mixture obtained afterwards passes through water-oil separating again can be obtained byproduct coal tar and waste water.This effluent part can be used as Prepare the water source of water-coal-slurry.The unit price of coal tar is 2000-2500 member/T, and the value for the coal tar that richness produces is higher.Pass through Remaining gas, which enters, after detar process removes naphthalene technique, and the naphthalene in rich gas is taken off to≤4mg/Nm³.Further preferably , the first purification process further includes except naphthalene technique, except naphthalene technique includes Processing Method for Washing Naphthalene Used of Light Tar, carbolineum except naphthalene and regeneration, rich oil are washed Naphthalene and regeneration.In this technique, vaporization at high temperature point can respectively obtain the differences such as similar diesel oil, gasoline, light petrol by cooling step by step The coal tar of the coal tar of temperature boiling range, similar light petrol boiling range is light tar.Because of light tar abundant raw material, Preferably, Processing Method for Washing Naphthalene Used of Light Tar can reach qualified synthesis gas.It is further preferred that the first purification process further includes adding hydrogen Technique, hydrogenation technique may choose whether according to presence of unsaturates in rich gas plus hydrogen, contains in the rich gas prepared in the present invention A certain amount of alkene, while preventing alkene is reforming from easily causing to tie carbon problem, it is therefore desirable to hydrogenation technique is set.Add hydrogen work Skill is mainly realized by hydrogenation catalyst, common are cobalt molybdenum hydrogenation catalyst, iron molybdenum hydrogenation catalyst.It is passed through a certain amount of Hydrogen so that alkene is transformed into alkane under the effect of the catalyst.

Preferably gasified reducing process using two-stage in the present invention, every grade of gasification reducing process is distinguished successively with respective first Purification process connection；The amount of dust in high-temperature oil gas generated after every grade of gasification reduction is larger, therefore, in order to advanced optimize Technique, every grade of gasification reducing process are first connect with respective dust collecting process, every grade of dust collecting process again with same detar work Skill is sequentially connected except naphthalene technique and hydrogenation technique etc., to save process procedure.

Sulfide is easy to cause reforming catalyst and methanol synthesis catalyst poisoning and deactivation, therefore in reforming work It needs to remove the sulfide in purified rich gas before skill.Purified rich gas, will be purified into the processing of thick sulfur removal technology H in rich gas₂S is removed to 20mg/Nm³Below.Thick sulfur removal technology uses wet method crude desulfurization, and Wet Flue Gas Desulfurization Technology is gas-liquid Reaction, reaction speed is fast, and desulfuration efficiency is high, is generally higher than 90%, technology maturation is widely applicable.Wet Flue Gas Desulfurization Technique compares Maturation, production run is safe and reliable, in numerous desulfurization technologies, occupies leading position always, accounts for desulfurization total installation of generating capacity 80% or more.Therefore, a large amount of H in rich gas is first tentatively taken off in wet desulphurization₂S removing.

Using wet method crude sulfur removal technology, general device can not operate under a certain pressure, and the tolerance because of processing is caused not have Compression is flowed through large-minded, and occupation area of equipment and package unit are also larger.And the sulfur-bearing total amount of the gas after thick desulfurization is not It is able to satisfy the requirement of subsequent reformation reforming catalyst and methanol synthesis catalyst to sulfur content.Therefore, after thick sulfur removal technology processing Gas first pass through the first compression process processing improve gas pressure, enter back into fine desulfurizing technology, the pressure of the first compression process For 20-25kg, temperature is at 300~400 DEG C.Fine desulfurizing technology is generally dry desulfurization, can operate, make under a certain pressure The effective component for the sulphur in unit volume that must be handled increases, and sulfur content removal rate also greatly improves, while can be substantially reduced essence The device of desulfurization, while improving the utilization rate of equipment.

Enter fine desulfurizing technology processing through the compressed gas of the first compression process, obtains reforming unstripped gas.Essence is de- Sulphur technique is dry desulfurization, is to remove sulfide using solid desulfurating agent.Thick sulfur removal technology takes off most sulfide It removes, remaining a small amount of sulfide is that it is reduced to 1mg/Nm by desulfurizing agent³Hereinafter, not only reducing in fine desulfurizing technology The cooperation of sorbent consumption, Er Qiejing, thick desulfurization twice technique is the reliable means of high-precision desulfurization, is reduced as far as possible Sulfur-bearing total amount in purified rich gas meets subsequent reformation reforming catalyst and methanol synthesis catalyst to sulfur content It is required that.

Dry desulfurization is divided into three types according to its property and desulphurization mechanism: hydrogenation type reforming catalyst, such as iron-molybdenum, nickel- Molybdenum etc., absorption-type convert absorbent, such as ZnO, iron oxide, manganese oxide, absorbent-type, such as active carbon, molecular sieve.For example, this The H of generation is absorbed using iron molybdenum catalytic hydroconversion organic sulfur (COS) in invention and with ZnO desulfurizing agent₂S, by purified richness Total sulfur in gas takes off 0.1ppm hereinafter, preventing sulfide from causing the catalyst poisoning in subsequent technique, reaches subsequent reformation and turns The requirement of the catalyst of chemical industry skill and the catalyst of methanol synthesizing process to sulfur content.For example, at a temperature of 300~400 DEG C, Absorb using the organic sulfur in the purified rich gas of iron molybdenum catalytic hydroconversion and with ZnO desulfurizing agent the H generated₂S will be purified The total sulfur in rich gas afterwards takes off 0.1ppm hereinafter, reaching reforming catalyst and methanol synthesis catalyst to sulfur content It is required that.

Leading to the substance of methanol synthesis catalyst poisoning and deactivation, there are also chloride and carbonyl metal compounds etc..In fine de-sulfur In technique, the cleanser of antichlor and decarbonylation metal carbonyl compound can be added simultaneously by these harmful substance removals.Chloride containing closes Object is easily reacted with metal ion, is easy to make the permanent poisoning of metal ion, is generally carried out dry method dechlorination, dechlorination using antichlor The main component of agent is basic anhydride, such as CaO, ZnO and Na₂O etc., chlorine in the purified rich gas obtained after purification Content is less than 0.1 × 10^-6.O.1x10 carbonyl metal compound needs in methyl methanol syngas are removed to^-6Hereinafter, metal carbonyl Compound is mainly with Fe (CO)₅、Ni(CO)₄Form exist, in fine desulfurizing technology addition removing metal carbonyl cleanser with Achieve the purpose that reduce carbonyl iron, carbonyl nickel in purified rich gas.

It include H in reforming unstripped gas₂、CO、CO₂And hydro carbons, hydro carbons generally refer to saturated hydrocarbons, hydro carbons is for synthesis Belong to inert gas for methanol, but hydro carbons can change synthesizing methanol by reforming technique needed for H₂And CO, it obtains Comprising containing H₂、CO、CO₂First conversion gas, successively increase the material quantity of methanol-fueled CLC, reduce the waste of resource.

Reforming unstripped gas is that gas each component is not in reforming unstripped gas through the reforming technique of some hydrocarbon It is directly that some hydrocarbon is reforming for CO and H through separating₂Hydrocarbon conversion technique because reforming purpose only be The hydrocarbon conversion is generated into CO and H₂, and itself contained some CO and H in reforming unstripped gas₂, there is no need to by hydrocarbon Class separates hydro carbons from reforming unstripped gas and carries out the reforming of hydro carbons again, saves work using such operation Skill step, high financial profit.

Reforming technique mainly includes steam reformation conversion, steam pure oxygen is reforming and pure oxygen it is reforming in one Kind is several.

Steam purity oxygen is reforming, steam reformation conversion is required to catalyst, and the catalyst of reforming technique is mostly Loaded catalyst, active component are mainly that Ni, Co, Fe, Cu etc. be nonmetallic and the noble metals such as Rh, Ru, Pt.Reforming one As need heat supply, can be by the way of direct heating or indirect heating.CO and H in first conversion gas₂Source be two Part, a part are the CO and H that some hydrocarbon is obtained by catalyzed conversion in reforming unstripped gas₂, another part is to reform Convert original H in unstripped gas₂And CO.

Reforming steam purity oxygen is to make reaction temperature using oxygen (pure oxygen) and a part of hydrocarbon fuel direct heating Reach 850-1300 DEG C, under the effect of the catalyst, some hydrocarbon in reforming unstripped gas reacts generation with vapor CO and H₂；Using extraneous heat supply when steam reformation converts, so that temperature is reached 850-1200 DEG C, make under the effect of the catalyst Some hydrocarbon in reforming unstripped gas is reacted with vapor generates CO and H₂；The key reaction mechanism of two methods are as follows:

(1)CmHn+mH₂O=mCO+1/2 (n+2m) H₂Main reaction, the endothermic reaction

(2)Side reaction, the endothermic reaction

With CH₄For, key reaction equation CH₄+H₂O→CO+3H₂, the H of generation₂Molar ratio with CO is 3:1, than Example is larger, and it is highly beneficial to convert gas to preparation first.In reforming technical process, there is H in reforming unstripped gas₂O In the presence of (vapor), with certain side reaction, side reaction is mainly CO and H₂O (vapor) shift conversion H₂'s Reaction.

Generally in the actual production process, vapor catalyzed reforming and on-catalytic reforming conversion either two is generallyd use The combination of person.

It (1) is about 1.98 using hydrogen-carbon ratio in reforming the first obtained conversion gas of one section of steam depth；

(2) using reforming the first obtained conversion gas of reforming+two sections of pure oxygens self-heating depth of one section of steam either shallow Middle hydrogen-carbon ratio is about 1.31-1.98.

It (3) is about 1.31 using hydrogen-carbon ratio in reforming the first obtained conversion gas of steam pure oxygen.

Water-coal-slurry is a kind of environmental clean fuel of New type coal base flow body, burning of coal characteristic has both been remained, but also with class It is the real clean coal technology in one, current China like the liquid-phase combustion application characteristic of heavy oil.Water-coal-slurry by 65-70% coal, The water of 29-34% and chemical addition agent less than 1%, are made by certain processing technology, appearance picture oil, good fluidity, It stores general 3-6 months and does not precipitate, convenient transportation, high combustion efficiency, pollutant (SO₂、NO_X) discharge it is low, about 2t water-coal-slurry can To substitute 1t fuel oil, can be used in the generation oil such as Industrial Boiler, station boiler and Industrial Stoves or coal, gas；Water-coal-slurry crosses water-coal-slurry Gasification process prepares CO and H₂, the raw material of methanol etc. can be prepared.

From the point of view of the long term growth of water-coal-slurry industry, pulping raw material should be based on cheap jet coal, weakly caking coal, no The high-orders coals such as low-order coals and anthracite, meager coal, poor Of-thin coal such as glutinous coal, lignite, or such as municipal sludge, industrial sludge, flotation coal The various solid waste such as mud, not only can be improved the economy of water-coal-slurry, also comply with country and rationally utilize coal and waste resource Policy.

Slurries additive agent mainly includes viscosity reduction dispersing agent and stabilizer.Wherein dispersing agent is mostly important, it is directly affected The quality and preparation cost of water-coal-slurry.(1), dispersing agent: the surface of coal has strong hydrophobicity, cannot tie closely with water A kind of slurry is synthesized, only will form a kind of wet walk in higher concentration.A small amount of dispersing agent is added in slurrying to change The surface nature of coal grain, making coal particle surface tightly is that additive molecule and hydration shell surround, and coal grain is allowed to be uniformly dispersed water In, and the mobility of water-coal-slurry is improved, dosage is about the 1% of coal.In general, dispersing agent is a kind of surfactant.It is common Surfactant have sulfonate type segregant surfactant (such as lignosulfonates tea sulfonate, alkenyl sulfonate), Polyoxyethylene punishment is non-from surfactant, water soluble polymer f polymer and anion surface active column and nonionic table The compound of face activating agent.(2), stabilizer: water-coal-slurry is one kind after all by solid, liquid two-phase coarse dispersion system, and coal grain holds very much again Easily spontaneously coalesce each other.Under gravity or other outer plus mass force effects, precipitating occurs and is inevitable.To prevent from sending out Stiff precipitating, it is necessary to a small amount of stabilizer be added.Stabilizer acts on of both having, and on the one hand makes water-coal-slurry that there is shearing to become Dilute rheological behavior has higher viscosity when the static storage of water-coal-slurry, viscosity can lower rapidly again after starting flowing； On the other hand make sediment that there is soft structure, prevent expendable hard precipitating.

In the waste water obtained in the first purification process, still contain a small amount of coal tar, mainly in the form of oil-in-water In the presence of COD (COD) is even higher between 5000mg/L~100000mg/L；Waste component is complicated, contains phenol Class, oil and ammonia nitrogen etc..Wherein, phenols mainly contains methyl class phenol, catechol, the aromatic hydrocarbon substance of the complexity such as benzenediol.It is useless The salinity of water is very high, and various ion concentrations are high, and the content of especially high price example is more prominent, this will give the performance of water-coal-slurry Bring significant impact.Phenols has certain acidity mostly, with the waste water slurrying of high salinity, it is difficult to reach high concentration water The requirement of coal slurry can mitigate destruction of the high salinity to coal slurry mobility due to the presence of Phenol for Waste Water class, therefore, contain phenol The waste water energy of class improves water-coal-slurry performance.Using waste water as production water-coal-slurry water source, be on the one hand in waste water in Impurity is more, and processing discharge is difficult, is used as preparation water-coal-slurry, not only solves the problems, such as sewage discharge difficulty, and effectively benefit With the original shortage of water resources in water resource, especially the Northwest；It is useless on the other hand compared with pure industrial water Be conducive to water-coal-slurry containing substances, the presence of the substances such as phenols such as a small amount of coal tar, phenols, lime-ash in water and be slurried, coal tar The presence of the substances such as oil and lime-ash increases the energy value of water-coal-slurry.

In the present invention, the main source for preparing the water of water-coal-slurry is waste water, and the source of coal substance is mainly coal dust.It will be upper Waste water is stated, coal dust is mixed with slurries additive agent solution, and water-coal-slurry can be obtained, and the concentration of water-coal-slurry is greater than 64.1wt%；It is viscous Degree is less than 1200mPas (at 20 DEG C of slurry temperature, shearing rate 100S-1)；Calorific value is greater than 18.51MJ/kg.

In addition, the present invention, which can also be used in technical process, generates other coal substances and water resource as preparation water-coal-slurry Raw material.Preferably, the exhaust gas that will be generated in drying course, remaining gas is again through cold after first passing through the processing of the first dust collecting process Solidifying process obtains waste water, and the source of water, does not fill to supplement waste water when this effluent part can also be used as preparation water-coal-slurry The shortage of water resource when sufficient, while also improving the utilization rate of water resource in low-order coal.It preferably, will be at gasification reducing process It manages obtained upgraded coal screening and obtains the coal dust that granularity is less than 1mm, the supplement of the coal resource as preparation water-coal-slurry, granularity is slightly Micro- upgraded coal greater than 1mm directly can sell or do stored energy source.Preferably, the greasy filth that will be generated during oil gas bosher For the source for doing the coal substance for preparing water-coal-slurry, greasy filth is used as preparation water-coal-slurry, can make full use of the resource in greasy filth.Make For the further improvement of technique in the present invention, in water-coal-slurry and O₂Before being handled by coal-water slurry gasification, water-coal-slurry is first through filtering Slurry processing.Considering slurry purpose is to remove the coarse granule occurred during water-coal-slurry processed and the certain sundries for being mixed into slurry, to prevent Water-coal-slurry blocking pipeline and nozzle etc. in storage and transportation and combustion process.

Finally, again by the water-coal-slurry and O of above-mentioned preparation₂It is obtained together by coal-water slurry gasification comprising CO and H₂? Two water-gas, the coal substance and O in key reaction water-coal-slurry in coal-water slurry gasification₂Burnup heat release, coal substance and water coal Water reaction in slurry generates CO and H₂.Here O₂It can be pure oxygen, be also possible to the oxygen rich gas of high-purity.Coal substance with H₂The reaction of O (vapor) is the endothermic reaction, reaction equation C+H₂O=CO+H₂, first it is passed through O₂So that a part is a small amount of Coal substance combustion heat release in water-coal-slurry so that environment temperature is rapidly achieved 800-1300 DEG C, then is passed through another part water coal Slurry reacts at this temperature with vapor generates CO and H₂, obtained gas is the second water-gas.In the actual production process, It is general to be uninterruptedly passed through O using continuous₂And vapor, so that coal substance and H in water-coal-slurry₂Between O (vapor) reaction not Disconnected the second water-gas of preparation.Due to containing the impurity such as a certain amount of dust in the second water-gas, the second water-gas passes through second The second conversion gas is obtained after purification process processing.Second purification process mainly includes cyclone dust removal, water scrubber and waste heat boiler Deng.

Upgraded coal and H₂The reaction of O (vapor) is the endothermic reaction, reaction equation C+H₂O=CO+H₂, also from gasification Obtained upgraded coal is the warm upgraded coal of band after original process reaction, because upgraded coal contains certain temperature, temperature be generally 350 DEG C- 800 DEG C, so its own has higher latent heat, this technique is first passed through on the basis of making full use of upgraded coal itself latent heat O₂So that a part of a small amount of upgraded coal combustion heat release, so that environment temperature is rapidly achieved 800-1300 DEG C, then is passed through other one Most of upgraded coal is reacted at this temperature with vapor generates CO and H₂, obtained gas is third water-gas, in practical life It is general to be uninterruptedly passed through O using continuous during production₂And vapor, so that upgraded coal reacts continual system with vapor Standby third water-gas.Because being removed by gasification in gasification reducing process stage most of volatile, tar etc., gained upgrading The content of coal substance is higher in coal, therefore less using foreign gas in the resulting third water-gas of upgraded coal.In addition, from gasification The upgraded coal that reducing process is handled, the upgraded coal granule size that gasification reducing process generates in the process is different, especially grain Lesser upgraded coal is spent, moisture-free is easy to produce fugitive dust, it has not been convenient to transport, be easy to cause environmental pollution, therefore by upgrading Screen separately wins the coal dust for taking granularity to be less than 1mm, and the supplement of the coal resource as preparation water-coal-slurry, granularity is mentioned less times greater than 1mm's Matter coal directly can sell or do stored energy source.

Major impurity gas in third water-gas is CO₂、H₂S, the impurity such as COS, there are also a small amount of dust.Pass through third Purification process will be that the de- impurity such as sour gas and a small amount of dust remove in water-gas, and the third after being purified converts gas. Third purification process includes Physical Absorption method, chemical absorption method and materialization absorption process.Physical Absorption method include low-temp methanol wash, Polyglycol dimethyl ether process, N-2 methyl pyrrolidone method etc..Wherein Physical Absorption method is more economical, mature, widely applies In industrial production, representative has low-temp methanol to wash method (Rectisol), polyglycol dimethyl ether process (NHD).Wherein especially with low temperature Methanol washes method industrialization maturation, and low-temp methanol washing process is using cold methanol as lyosoption, using methanol at low temperature to sour gas Body (CO₂、 H₂S, COS etc.) the great good characteristic of solubility, the sour gas in third water-gas is removed, is a kind of physics suction Receipts method.Low-temp methanol washing process is recognized gas purification technique the most economic and high degree of purification domestic and international at present, is had The characteristics of other desulfurization, decarburization technique cannot replace, such as: purified gas is high-quality, and degree of purification is high, has selective absorbing CO₂、 H₂The characteristic of S and CO, solvent is cheap and easy to get, and low energy consumption, and running expense is low, production run stabilization, reliable etc..Therefore, work is purified The preferred low-temp methanol washing process of skill, to remove the sour gas in third water-gas.Third converts CO in gas₂Percentage by volume About 32.1%, CO percentage by volume about 19.02%, H₂S percentage by volume about 0.23%, H₂Percentage by volume about 46.02%.

Active principle in gas needed for methanol-fueled CLC is H₂、CO、CO₂, in methyl methanol syngas hydrogen-carbon ratio and require There is following formula:

R=(H₂-CO₂)/(CO+CO₂), wherein the hydrogen-carbon ratio R value theoretical value of methyl methanol syngas is 2.0, and optimum value is 2.05-2.1。

When the R value of methyl methanol syngas is greater than 2.1, represents that the more carbon of hydrogen are few, and methanol synthesis loop circulating flow rate is big at this time, follow Ring air compressor power consumption is big, and methanol purge gas amount is also big, and many raw materials pass through the useful H of multiple process preparation₂、CO、CO₂With Methane etc. is sent into fuel system burn-up with methanol purge gas, causes the serious wasting of resources, and consumption of raw materials amount increases.Work as methanol When the R value of synthesis gas is less than 2.05, it is not able to satisfy the requirement of methanol-fueled CLC.

And the R value that gained first converts in gas after reforming technique is respectively less than 2.05, the second conversion gas and third convert The R value of gas can not generally reach 2.05-2.1 just, therefore, can convert gas to the first conversion gas, the second conversion gas and third One of, after the R value adjustment of two kinds or three kinds and mix, R value circle of the methyl methanol syngas obtained after mixing is in 2.05- Between 2.1, specific adjust can adjust according to practical condition.Adjusting R value can be turned by decarburization mend carbon technology, variation It chemical industry skill and mends one of hydrogen technique or several realizes.

Decarburization mend carbon technology includes decarbonization process and mend carbon technology.When the first conversion gas, the second conversion gas and third conversion When the R value of one or more of gas is greater than 2.1, CO is passed through into the first conversion gas by mend carbon technology respectively₂Or high-purity CO₂, obtain standard compliant methyl methanol syngas；When first convert it is a kind of in gas, the second conversion gas and third conversion gas or When several R values is less than 2.05, one in gas is converted by the first conversion of decarbonization process removing gas, the second conversion gas and third Part CO₂, so that the R value value range of obtained methyl methanol syngas is adjusted to 2.05-2.1.

Industrial removing CO₂Method it is very much, can generally speaking be divided into two major classes: one kind is solvent absorption, another Class is pressure swing adsorption method (PSA).Solvent absorption includes Physical Absorption method, chemical absorption method and physicochemical adsorption method, Physical Absorption method, as low-temp methanol washes method, polyglycol dimethyl ether process, propylene carbonate ester process；Chemical absorption method, generally as NaOH, KOH, Ba (OH)₂CO can be very effectively absorbed Deng the stronger lye of alkalinity₂Gas, principle are because of CO₂Gas is molten Carbonic acid is generated in water, the hydrogen ion that the ionization of carbonic acid fraction generates is reacted with the hydroxide ion in lye generates water, therefore can Remove CO₂.PSA method is or else lower with different adsorption capacities, adsorption rate and suction with partial pressure to adsorbate using adsorbent Attached power, and under a certain pressure to the characteristic for thering is selection to adsorb by each component of isolated admixture of gas, pressurized adsorbent removes Go impurities in feed gas component, these impurity of removed under reduced pressure and regenerate adsorbent, the method have simple process, operation Stablize, low energy consumption, without " three wastes " emission problem the advantages that, be a kind of de- CO of energy conservation₂New technology, have a extensive future.In addition this work The CO of the removing of skill work₂Also it can be recycled recycling.

Turn in addition, the first conversion gas, the second conversion gas and third can also be adjusted by mending hydrogen technique substitution decarbonization process Change R value one or several kinds of in gas, so that R value circle is between 2.05-2.1.By the H in suitable external world₂Or the H of high-purity₂ It is passed through in conversion gas, makes its R value in the range of 2.05-2.1, to save decarbonization process, reduce process flow.Here H₂Or the H of high-purity₂It can be obtained from extraneous directly purchase, it can also be after subsequent methanol synthesizing process in remaining methanol purge gas Recycle the H of purification₂, the H of purification₂It can be directly supplemented into the source in first conversion gas etc. as the hydrogen for mending hydrogen technique, it can also With the H that will be purified from methanol purge gas₂Enter subsequent second compression process together as circulating air and methyl methanol syngas, Recycling for resource is not only realized, the process costs expenditure also saved.

As shown in Fig. 2, the first conversion gas, the second conversion gas and third conversion one of gas or several entering decarburization Before mend carbon technology, shift conversion technique can be first passed through and obtain the first conversion gas, the second conversion gas and third conversion gas, first One or more of conversion gas, the second conversion gas and third conversion gas pass through after decarburization mend carbon technology and by being mixed to get Methyl methanol syngas, the hydrogen-carbon ratio R value of the methyl methanol syngas are 2.05~2.1.

Key reaction in shift conversion technique are as follows:The fuel factor of this reaction regards H₂The state of O Depending on, then it is the endothermic reaction if liquid water, is then exothermic reaction if vapor.Reacting condition is reversible reaction, is put down Weighing apparatus constant reduces with the increase of pressure, can increase H in gas₂Percentage by volume, reduce the percentage by volume of CO, but It will increase CO simultaneously₂, therefore also need to remove CO using decarbonization process after generally using shift conversion technique₂.According to first The R value of conversion gas, the second conversion gas and third conversion gas determines the choice of shift conversion technique, and general R value is close to 2.05- When 2.1, shift conversion technique is not used, R value is quickly directly adjusted by subsequent decarburization mend carbon technology；R value is much smaller than When 2.05-2.1, increase shift conversion technique, R value is increased with this, the decarburization mend carbon technology after recycling adjusts R value.First Vapor is practically free of in conversion gas, the second conversion gas and third conversion gas wherein contain vapor, the especially second conversion gas It is the coal water slurry gasification gained by liquid, containing a large amount of remaining vapor after the gasification in water-coal-slurry, this part vapor can As the raw material of shift conversion reaction, it is therefore preferable that the second conversion gas increases the volume hundred of wherein CO by shift conversion reaction Divide ratio.

The methyl methanol syngas obtained from decarburization mend carbon technology passes through the second compression process first and carries out compression processing, is conducive to The pressure 40-50kg of the second compression process of synthesis of subsequent methanol, temperature are 200-350 DEG C.Due to passing through the second compression process The pressure 40-50kg of treated gas uses low-pressure process synthesizing methanol.In order to realize isobaric methanol-fueled CLC, methanol is saved Synthesic gas compressor and compression power consumption reduce investment cost and production cost, and the production and purification of methyl methanol syngas are generally low Pressure carries out.Methyl methanol syngas enters methanol synthesizing process, and catalyst needed for methanol-fueled CLC is added, and obtains after reaction thick Methanol and methanol purge gas.Methanol synthesis catalyst generally can be divided into zinc chromia catalyst, copper-based catalysts, palladium series catalyst and Molybdenum series catalyst etc. is commonly copper zinc aluminium-based catalyst in industrial production.The purity of crude carbinol in the present invention is 95% left It is right.

The main chemical equation of synthesizing methanol is as follows:

Since, there are many side reactions, these side reactions generate a large amount of inert gas and in work in Production of methanol It is constantly accumulated in skill, influences the normal operation of methanol synthesizing process, it is necessary to constantly discharged, this discharge gas is known as methanol Periodic off-gases.The main component of methanol purge gas is H₂、CO、H₂O and CH₄Inert gases are waited, wherein H₂And CH₄Volumn concentration Account for about 90% or so.Using the H in pressure swing adsorption recycling methanol purge gas₂, increase yield of methanol can be reached and energy-saving and emission-reduction are double Weight purpose.The H in methanol purge gas is recycled by pressure-variable adsorption etc.₂It supplements in reforming gas, it can also will be from subsequent methanol The H recycled in periodic off-gases₂As the H in the second compression process in circulating air supplement machine, in addition recycled₂Also it can be used as fuel combustion Heat supply.Or without Pressure Swing Adsorption H₂, directly conduct in the second compression process is passed through using methanol purge gas as circulating air A part of raw material of methanol-fueled CLC.In addition in Production of methanol, the pressure of rich producing steam is generally 2.5MPa or so, this Some vapor, which can be used as present apparatus methyl alcohol synthetic reactor by-product, can be used as the vapor of steam reformation conversion in reforming technique Source, waste heat waste water reuse save this process costs expenditure.

The crude carbinol obtained from methanol synthesizing process enters methanol rectification technique and obtains product methanol.Industrial refining crude first Alcohol is broadly divided into two methods: one is the methods of physics, i.e., using different components such as methanol, water and organic impurities thick Different volatility in methanol mixed solution is isolated by distillation；Another kind is chemical method, i.e., still not by distillation The quality requirement of purification methanol can be reached, but acidic materials such as some impurity such as formic acid that must be driven off again can then pass through Caustic soda is added to be neutralized to remove.The method of two kinds of purification methanol can industrially be divided into list based on distillating method Tower, double tower, three towers and four towers totally four kinds of technique.Single column technique can be used for using fuel methanol as the essence of the crude carbinol of target product System；Double tower, three towers and four tower process are used primarily in using the high methanol of purity requirement as the purification of the crude carbinol of target product.Its In, double tower process is gradually eliminated since its energy consumption is higher with respect to three towers and four tower process, large size newly-built at present Methanol-fueled CLC factory is all made of three towers improved on the basis of double tower process and four tower process, energy consumption can compared with double tower process To reduce 30%~40%.The rate of recovery of methanol rectification technique about 99.5%, gained methanol are colourless transparent liquid, no foreign odor Taste, impurity is few, and quality is high, and refined methanol specification meets GB338-2011 high-class product methanol quality index request.

In conclusion the method in the present invention, obtains volatile matter by reduction of gasifying in the low-order coal after drying, then will CO and H needed for the reforming acquisition methanol-fueled CLC raw material such as the hydro carbons in volatile matter₂, substantially effectively sharp to prepare methanol With the volatile matter in low-order coal；By preparing methanol for gasification reduction acquisition upgraded coal in low-order coal is raw material, it is utilized Coal substance in low-order coal；It is used to make water-coal-slurry in addition, the present invention effectively recycles moisture and coal dust in low-order coal etc., Waste utilization economizes on resources, and useless water reuse solves the problems, such as that discharged wastewater met the national standard difficulty, the recycling of coal dust solve Problem of environmental pollution；Methanol contaminant prepared by the above number of ways is few, and quality is high, substantially increases the utilization of low-order coal Rate meets the coal high-efficiency clean utilization that country advocates energetically.

The above, the above embodiments are merely illustrative of the technical solutions of the present invention, rather than its limitations；Although referring to before Stating embodiment, invention is explained in detail, those skilled in the art should understand that: it still can be to preceding Technical solution documented by each embodiment is stated to modify or equivalent replacement of some of the technical features；And these It modifies or replaces, the spirit and scope for technical solution of various embodiments of the present invention that it does not separate the essence of the corresponding technical solution.

Claims

1. a kind of method for preparing methanol using low-order coal multipath, it is characterised in that: comprise the following steps that:

(1) low-order coal and exhaust gas after low-order coal drying process is dried, the exhaust gas pass through the first dust collecting process Obtain coal dust；

(2) low-order coal after drying described in step (1) is handled to obtain rich gas and upgraded coal by the reducing process that gasifies, it is described The reducing process that gasifies is the chemical reaction process heated under anaerobic or micro-oxygen conditions to the low-order coal after drying；

(4) purified rich gas described in step (3) passes sequentially through sulfur removal technology and the first compression process handles to obtain reformation turn Change unstripped gas；The reforming unstripped gas is obtained by reforming process comprising CO, CO₂And H₂First conversion gas；

(5) water-coal-slurry is obtained after mixing coal dust described in waste water described in step (3), step (1) with slurries additive agent, it will The water-coal-slurry and O₂It handles to obtain comprising CO, CO by coal-water slurry gasification₂And H₂The second water-gas, described second Water-gas obtains the second conversion gas after handling by the second purification process；

(6) by upgraded coal described in step (2) by with H₂O and O₂Reaction preparation includes CO, CO₂And H₂Third water-gas, will The third water-gas obtains third and converts gas after handling by third purification process；

(7) third in the second conversion gas in the first conversion gas described in step (4), step (5) and step (6) is converted in gas At least one is by being selected from one or more of decarburization mend carbon technology, shift conversion technique and benefit hydrogen technique and being mixed to get first Alcohol synthesis gas, the hydrogen-carbon ratio R value of the methyl methanol syngas are 2.05~2.1；

(8), methyl methanol syngas described in step (7) passes sequentially through the second compression process, methanol synthesizing process obtains crude carbinol and Methanol purge gas, the crude carbinol obtain product methanol by methanol rectification technique.

2. a kind of method for preparing methanol using low-order coal multipath as described in claim 1, it is characterised in that: step (4) Described in sulfur removal technology include fine desulfurizing technology and thick sulfur removal technology, the purified rich gas pass sequentially through thick sulfur removal technology, First compression process and fine desulfurizing technology handle to obtain reforming unstripped gas.

3. a kind of method for preparing methanol using low-order coal multipath as described in claim 1, it is characterised in that: step (3) Described in the first purification process include dust collecting process and detar technique.

4. a kind of method for preparing methanol using low-order coal multipath as described in claim 1, it is characterised in that: the transformation Conversion process be during reforming unstripped gas to methyl methanol syngas by CO by with H₂O response transform is converted into H₂。

5. a kind of method for preparing methanol using low-order coal multipath as described in claim 1, it is characterised in that: by step (4) the first conversion gas described in, at least one of third conversion gas first leads in the second conversion gas and step (6) in step (5) It crosses shift conversion technique and obtains the first conversion gas, the second conversion gas and third conversion gas, first conversion gas, the second conversion gas Pass through decarburization mend carbon technology at least one of third conversion gas and is mixed to get methyl methanol syngas.

6. a kind of method for preparing methanol using low-order coal multipath as claimed in claim 5, it is characterised in that: step (4) Described in the second conversion gas the second conversion gas obtained by shift conversion technique, second in second conversion gas and step (5) At least one of third conversion gas described in conversion gas, step (6) passes through decarburization mend carbon technology and is mixed to get methyl methanol syngas.

7. a kind of method for preparing methanol using low-order coal multipath as described in claim 1, it is characterised in that: step (7) Described in decarburization mend carbon technology be that the first conversion gas, the second conversion gas and third convert one of gas or several hydrogen When carbon ratio R value is greater than 2.1, it is passed through CO₂, so that R value is adjusted to 2.05-2.1；The first conversion gas, the second conversion gas and the When one of three conversion gasifications or several hydrogen-carbon ratio R values are less than 2.05, CO is removed₂, so that R value is adjusted to 2.05- 2.1。

8. a kind of method for preparing methanol using low-order coal multipath as described in claim 1, it is characterised in that: step (4) Middle benefit hydrogen technique is that H is added during reforming gas to methyl methanol syngas₂Technique.

9. a kind of method for preparing methanol using low-order coal multipath as described in claim 1, it is characterised in that: step (1) Described in coal dust granularity be less than 1mm.

10. a kind of method for preparing methanol using low-order coal multipath as described in claim 1, it is characterised in that: step (2) Described in gasification reducing process reaction temperature be 350-800 DEG C.

11. a kind of method for preparing methanol using low-order coal multipath as described in claim 1, it is characterised in that: step (4) Described in reforming unstripped gas through reforming process be reforming unstripped gas in gas each component without isolation, directly It connects some hydrocarbon in the reforming unstripped gas is reforming for CO and H₂Reforming technique.

12. a kind of method for preparing methanol using low-order coal multipath as claimed in claim 11, it is characterised in that: step (4) reforming technique described in is converted selected from steam reformation, steam pure oxygen is reforming and pure oxygen reforming therein one Kind is several.

13. a kind of method for preparing methanol using low-order coal multipath as described in claim 1, it is characterised in that: step (8) Described in the second compression process pressure 40-50kg, temperature be 200-350 DEG C.