CN2319410Y

CN2319410Y - Cooperative prodn. Unit for two-stage gasifying fluidized bed coke loaded hot gas and steam

Info

Publication number: CN2319410Y
Application number: CN 97227686
Authority: CN
Inventors: 张绪祎; 程荫桐; 齐茂展; 陈勖
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 1997-09-26
Filing date: 1997-09-26
Publication date: 1999-05-19
Anticipated expiration: 2007-09-26

Abstract

The two-stage gasification fluidized bed coke heat-carrying gas-steam cogeneration device is a further improvement on the basis of the fluidized bed coke heat-carrying gas-steam cogeneration device. Its main feature is that the coal gas generating device includes two fluidized bed gasification reactors. The device uses coke as the heat carrier, which effectively solves the problem of low carbon concentration in the gasification reactor, ensures sufficient heat capacity and high reaction temperature, and thus greatly increases the gas production rate; at the same time, due to Using two fluidized bed gasification reactors, according to the needs, can respectively obtain city gas containing more low-carbon hydrocarbons or rich in tar, a ship of synthetic raw material gas and water gas that can be used as synthetic ammonia raw material gas, so it has a wider range applicability.

Description

Two-stage gasification fluidized-bed coke carried heat coal gas-steam co-producing device

The utility model relates to a kind of fluidized-bed coal gas-steam co-producing equipment with gas maked coal.

In the prior art, adopt the method for gas maked coal a lot, several except routine as coke oven, upright furnace, two sections stoves of water-gas, the pressurization lurgi gasifier etc., circulating fluidized bed fine coal gas producing technology, particularly the integral process of circulation bed coal gas-steam co-producing has also obtained corresponding development and application at present.Chinese invention patent " circulation bed coal gas-steam co-producing technology method and apparatus " (application number 91103896.5), adopt circular fluid bed to produce steam exactly with three vortex inner separators, and the next-door neighbour arranges that a fluidized bed coal pyrolyzer produces coal gas outside this boiler, employing provides pyrolysis of coal required thermal source through the hot ash that separator separates as thermal barrier, and semicoke that produces behind the pulverized coal pyrolysis and part raw coal are as the fuel of boiler.This kind technology has simple in structure, and running cost is low, characteristics such as energy reasonable energy utilization, and calorific value of gas uses for resident living in both can having produced, and can produce steam heating and generating simultaneously.But because above-mentioned process using circulating ash is as thermal barrier, thereby make the concentration of the coke in the gasifying reactor very low, be unfavorable for water-gas reaction, so gas yield is low, and the circulation of the iron oxygen carrier in the circulating ash makes the CO concentration reduction in the coal gas, CO ₂Concentration raises, and has reduced the calorific value of coal gas; On the other hand, owing to only separate by separator, its internal circulating load is little as the circulating ash of thermal barrier, causes the temperature in the pyrolyzer on the low side, and considerable volatile matter is remained in the semicoke, and this has also influenced system gas productive rate.

In order to overcome the problems referred to above, Chinese patent application (application number 96109833.3) proposes a kind of fluidized-bed coke carried heat coal gas-steam co-producing technology and device.It comprises fluidized-bed combustion boiler system that produces steam and the gas generating system of producing coal gas.Its gas generating system comprises that a fluidized bed gasification reactor and top be equipped with the burning riser tube and the communicating valve of gas-solid separator.Scission reaction and water-gas reaction take place in raw coal in fluidized bed gasification reactor, and discharge coal gas, and Jiao of generation enters riser tube burning and heat release.A large amount of Jiao is circulated between riser tube and fluidized-bed reactor, brings the heat that burnt burning in the riser tube discharges into fluidized bed gasification reactor, and as the thermal source of coal gasification reaction, surplus Jiao sends into boiler and burns.This kind technology has adopted with Jiaozhuo thermal barrier, has solved the low excessively problem of carbon concentration in the gasifying reactor effectively, has guaranteed enough heat loads and higher temperature of reaction, has improved gas yield greatly.This device can be as required, feed different fluidizing mediums after, can produce town gas, general synthetic raw gas or syngas for synthetic ammonia.

When producing syngas for synthetic ammonia, fluidizing medium in the fluidized bed gasification reactor is a steam, this moment not only blowing air but also logical steam of riser tube bottom, the promptly burnt intensification of in riser tube, both having burnt, water-gas reaction takes place again, and the gas mixture of generation can be common to the coal gas produced in the fluidized bed gasification reactor and make syngas for synthetic ammonia.

In the gasification in reactor,, contain product methane and other lower carbon number hydrocarbons of more scission reaction in the coal gas of generation, after the gas mixture of riser tube generation mixes, still contain these hydrocarbon because raw coal not only scission reaction takes place but also water-gas reaction takes place.And the required raw material of Ammonia Production is based on the product of water-gas reaction, and lower carbon number hydrocarbons such as methane must be removed from unstripped gas.But under present circumstances, the technical difficulty that removes hydrocarbon from the water-gas gas mixture is very big, therefore, is necessary technical equipment is further improved, to produce more satisfactory syngas for synthetic ammonia.

At above-mentioned situation, the purpose of this utility model and task are that fluidized-bed coke carried heat coal gas-steam co-producing device is made improvements, make it can not only improve gas yield effectively, and the scission reaction of raw coal and water-gas reaction process are separated, obtain town gas and general synthetic raw gas that contains more lower carbon number hydrocarbons or be rich in tar or the water-gas that can be used as syngas for synthetic ammonia respectively, make it have suitability widely.

The utility model is achieved through the following technical solutions: it mainly is made up of the gazogene of the fluidized-bed combustion boiler of producing steam and production coal gas, its gazogene comprises fluidized bed gasification reactor and a riser tube, gas-solid separating device is equipped with at the riser tube top, it is characterized in that gazogene comprises the two-step fluidized bed gasifying reactor, between the gas-solid separating device at riser tube top and each fluidized bed gasification reactor communicating valve is housed respectively, the riser tube bottom is connected with each fluidized bed gasification reactor bottom by tremie pipe and variable valve respectively.

In system when operation,, the coal that is used for producing coal gas directly joins first step fluidized bed gasification reactor, and this reactor is made fluidizing medium with the mixture of steam, coal gas or steam and coal gas respectively.Scission reaction takes place in coal therein, and the middle calorific value of gas of generation and tar steam are flowed out by the gasifying reactor top; Jiao that gasification reaction generates discharges from the fluidized bed gasification reactor bottom with circulation Jiao as thermal barrier, flows into riser tube through tremie pipe and variable valve.The air that feeds from the riser tube bottom is carrying burnt with the certain speed rising, and burning, heat release simultaneously.A burnt here gas-solid separating device that is heated and is thus lifted to the top.Separated Jiao who gets off is divided into two-way, wherein a part turns back to the first step gasifying reactor of coal, to provide the coal scission reaction required heat, another part then flows in the fluidized bed gasification reactor of the second stage and (adopts steam as fluidizing medium), Jiao therein with the vapor generation water-gas reaction, the water-gas of generation flows out from the fluidized bed gasification reactor top.Discharging hot flue gas by the riser tube top sends into fluidized-bed combustion boiler and makes waste heat and absorb.

Accompanying drawing 1 is the structural principle synoptic diagram of the former invention of generation town gas or general synthetic raw gas.

Accompanying drawing 2 is for generating the technical process of the present invention and the structural principle synoptic diagram of syngas for synthetic ammonia and town gas or general synthetic raw gas.

Describe principle of work of the present invention in detail below in conjunction with accompanying drawing, concrete structure and embodiment:

The utility model mainly comprises fluidized-bed combustion boiler 1 and the gazogene of producing steam, this gazogene be by two-step fluidized bed gasifying reactor 2 and 2 ', riser tube 3, gas-solid separating device 4 and corresponding valve and pipeline are formed.Raw coal joins in the first step gasifying reactor 2, and gasifying reactor 2 is provided with coal feeding hole 8 and gas exit 9 and fluidizing medium import 10; Second stage gasifying reactor 2 ' can not establish coal feeding hole, only be provided with gas exit 9 ' and the import 10 of fluidizing medium '.The gasification raw coal enters gasifying reactor 2 by coal feeding hole 8, and its bed temperature is controlled at 500 ℃-850 ℃.Its fluidizing medium is looked the coal gas purposes difference of generation and is distinguished to some extent.When production city coal gas, its fluidizing medium should adopt coal gas, and when producing synthetic raw gas, adopts the gas mixture of steam or steam and coal gas to make fluidizing medium.Jiao who generates after the gasification falls into the tremie pipe 7 of gasifying reactor 2 bottoms with circulation Jiao as thermal barrier, and tremie pipe is connected with a L type variable valve 6, the burnt bottom that flows into riser tube through this valve.

Riser tube bottom 12 bubbling airs.Air enters riser tube with certain speed, is carrying Jiao and is moving upward, and with Jiao combustion reactions is taking place.When circulation Jiao arrived the gas-solid separating device 4 at riser tube top, the burning liberated heat was heated to 950 ℃-1000 ℃ to gas-solid mixture.By Jiao that gas-solid separator separates, a part flows into gasifying reactor 2 through communicating valve 5, and the heat of coal cracking and gasification is provided to gasifier as the thermal barrier of recirculation; And another part Jiao through communicating valve 5 ' inflow gasifying reactor 2 ', its bed temperature is controlled at 850 ℃-950 ℃.Gasifying reactor 2 ' employing steam and Air mixing gas is as fluidizing medium, the burnt and steam generation water-gas reaction of circulation, and the heat that reacts required is provided by circulation Jiao as thermal cyclic carrier.The coal gas that generates is from gas exit 9 ' discharge.Surplus Jiaozhuo after the gasification fall into together for circulation is burnt the tremie pipe 7 of gasifying reactor 2 ' bottom ', tremie pipe and a L type variable valve 6 ' be connected, surplus Jiao flows into the bottom of riser tube 3 through this valve, participates in again circulating.

Send into boiler 1 burning from the hot flue gas that gas-solid separating device is separated.

From the raw gas of gasifying reactor 2 and 2 ' come out respectively by the gas exit 9 and 9 ' outflow at gasifier top, enter respectively earlier a cyclonic separator 11 and 11 ', its entrained solid particle separation is got off, carry out further clean then.Also can send into boiler combustion by the coke powder that cyclonic separator separates.

The present invention compared with prior art has the following advantages and beneficial effect: the present invention with The full gasification installation of general coal is compared, and not only technology is simple, and investment and cost are lower, and use Can reasonably utilize the energy; Make the coal gas of heat carrier-steam co-producing device phase with circulating ash Ratio take Jiaozhuo as heat carrier owing to adopted, and has effectively solved carbon in the gasification reactor The problem that concentration is excessively low has guaranteed enough heat loads and higher reaction temperature, thereby big Improved greatly gas yield; Owing to adopted the two-step fluidized bed gasification reactor, can distinguish Obtain containing town gas and the general synthetic raw gas of more lower carbon number hydrocarbons or can be used as synthetic The water-gas of ammonia unstripped gas, thereby have widely applicability.

Claims

1, a kind of two-stage gasification fluidized-bed coke carried heat coal gas one steam combination preparing device, mainly form by the gazogene of the fluidized-bed combustion boiler [1] of producing steam and production coal gas, its gazogene comprises fluidized bed gasification reactor and a riser tube 3, gas-solid separating device [4] is equipped with at the riser tube top, it is characterized in that gazogene comprises two-step fluidized bed gasifying reactor [2] and [2 '], communicating valve [5] and [5 '] are housed respectively between the gas-solid separating device at riser tube top and each fluidized bed gasification reactor, and the riser tube bottom is respectively by tremie pipe [7], [7 '] and variable valve [6], [6 '] is connected with each fluidized-bed reactor bottom.

2, according to the described two-stage gasification of claim 1 fluidized-bed coke carried heat coal gas one steam combination preparing device, it is characterized in that on first step fluidized bed gasification reactor, being provided with coal feeding hole [8], fluidizing medium inlet [10] and gas exit [9], and on the fluidized bed gasification reactor of the second stage, only be provided with fluidizing medium inlet [10 '] and gas exit [9 '].