CN1639306A

CN1639306A - Method for gasification of a solid carbonaceous feed and a reactor for use in such a method

Info

Publication number: CN1639306A
Application number: CNA028292588A
Authority: CN
Inventors: J·H·斯蒂尔
Original assignee: Shell Internationale Research Maatschappij BV
Current assignee: Shell Internationale Research Maatschappij BV
Priority date: 2002-07-02
Filing date: 2002-07-02
Publication date: 2005-07-13
Also published as: GB2405603A; WO2004005438A1; GB0428282D0; AU2002368080A1; JP2005531673A; US20060076272A1; EP1532229A1

Abstract

A method for gasification of a solid carboneous feed, wherein said gasification is performed in an elongated gasification reactor vessel comprising a gasifier unit, a co-axial positioned cooled channel through which the dust-loaded hot-gaseous product of the gasifier unit is discharged from the reactor, and means to supply a quench gas to the dust-loaded hot gaseous product at a position downstream of said gasifier unit, wherein to an annular space between the reactor vessel wall and the cooled channel a dust-free gas is supplied at a rate sufficient to ensure that no dust-loaded hot gas will flow from the cooled channel to said annular space.

Description

The gasification process of solid carbonaceous feed and the reactor that is used for this method

The present invention relates to a kind of gasification process of solid carbonaceous feed, wherein said gasification is implemented in the gasification reactor vessels of a prolongation, and described reactor vessel comprises: gasifier unit; Discharge from reactor by the negative heat dust gas product of this passage gasifier unit the cooling channel of coaxial arrangement; And the equipment that quench gas is provided for negative heat dust gas product in the downstream of described gasifier unit.

This method is stated in US-A-4859213.The document has been described a typical coal gasification method, and described method is implemented in the gasification reactor vessels of a prolongation, and wherein said gasification reactor vessels comprises: gasifier unit; Discharge from reactor by the negative heat dust gas product of this passage gasifier unit the cooling channel of coaxial arrangement; And the equipment that quench gas is provided for negative heat dust gas product in the downstream of described gasifier unit.By burner with oxygen-containing gas in gasifier unit charging from the comminuted coal of coal feed circuit.In gasifier, comminuted coal is the gas (synthetic gas) that contains carbon monoxide-hydrogen by the oxygen partial oxidation, and it also is known as product gas in addition.For ash gravitate in the cooling channel of slag form moves to the slag bath jar that is arranged in the extension reactor lower end.The product gas that contains dust and entrained liquid slag droplets rises to quench zone in the cooling channel.Product gas behind the chilling flows out gasifying reactor by pipeline, enters waste heat boiler or syngas cooler.In so-called solids removal district, from resulting chilled product gas, remove solid.Charging is back in the cooling channel as quench gas by recycle gas compressor from the part in solids removal district cleaning and refrigerative gas then.The quench gas that enters the cooling channel makes product air cooling but, thereby the flying dust slag granules of carrying secretly is solidified, and can not stick on pipeline or the waste heat boiler surface.

In the carbon gasification method, for example described in US-A-4859213, carbon raw material is converted into the product gas of heat under high temperature and high pressure.Inert ash components part contained in carbon is discharged from gasifying reactor with the logistics of hot product gas with the form of fine dust.Because vapor pressure is up to 50bar and higher, so parts of in gasification process, using, heating surface as gasifying reactor, fast cooling device, cooling channel, pipeline and downstream heat exchanger, all must operate in pressure wall, wherein said pressure wall can realize by one or more pressurized vessels or pressure shield.For the synthetic gas high temperature of pressure shield tolerance above 1500 ℃ of guard reactor, quench tube and cooling channel all are furnished with water-cooled cooling surface.The cold quench gas that the hot product gas of negative dirt utilizes the quench gas feeding unit to provide is cooled to about 900 ℃ temperature.Further cool off on surface at one or more interchanger in described quenching unit downstream, thereby produce steam.

Between the pressure wall of gasifier unit, quenching unit, cooling channel and gasifying reactor, form an annular space, described in US-A-4859213.

The cooling surface of cooling channel can only bear less gas side pressure reduction.Therefore, the internal pressure of cooling channel and annular space needs compensation basically.The perforate of fluid connection cooling channel and annular space is the sliding point in the wall of cooling channel, and it is used for compensating the thermal expansion and the perforate of quenching unit.

For this point, from Dr.G.Keintzel and Dipl.-Ing.Gawlowski at meeting EPOS 2000-International Conferencce on Efficiency, Cost, Optimisation, Simulation and Environmental Aspects of Energyand Process Systems, July 5-7,2000, University of Twente, Enschede, speech on the The Netherlands " standard of gasifier and syngas cooler (Criteria for Design of Gasifier and Syngas Cooler) ", figure " heating surface in the syngas cooler (Heating Surfaces in the SyngasCooler) " in as can be known, in order to obtain pressure compensation by gas shield with the isolating hot gas flow-guiding channel of pressure wall section place at least, the sliding point that formation links to each other with the cooling channel opening, or provide the gas permeability piston for it.Therefore, in pressure compensated process, negative dirt hot product gas enters annular space.Have been found that, in plant-scale carbon gasification device, because hot gas can cool down at cooling surface side and the pressure wall place towards annular space, and cooled gas can flow back to the cooling channel by sliding point, so in adding the annular space of gas, taken place undesirablely to flow promptly so-called secondary flow at gas side.In such a way, undesirable heating and ash fall will take place in the zone of each pressure wall.This might cause operation failure.

An object of the present invention is to provide a kind of gasification process as described above basically, wherein the product gas of negative dirt can not enter annular space, and has therefore avoided the deposition of dust.

Following method will realize this purpose.A kind of gasification process of solid carbonaceous feed, wherein said gasification is implemented in the gasification reactor vessels of a prolongation, and described reactor vessel comprises: gasifier unit; Discharge from reactor by the negative heat dust gas product of this passage gasifier unit the cooling channel of coaxial arrangement; Provide the equipment of quench gas with the downstream that is positioned at described gasifier unit for bearing the heat dust gas product, wherein to provide dust-free gas in the annular space of enough flows between reactor vessel wall and cooling channel, to guarantee that not having negative dirt hot gas flows into described annular space from the cooling channel.

The applicant has been found that by providing this dust-free gas to described annular space, in the wall of cooling channel, as described in sliding point and chilling the equipment place is provided, do not have negative dirt hot product gas and pass through opening.The forward flow that will have so-called dust-free gas from annular space to the cooling channel.In order to reach this forward flow, the flow of supplying with the dust-free gas of described annular space preferably makes the pressure in the described annular space equal at least or just above the pressure in the described cooling channel.Aforesaid method is also referred to as method for pressure compensation.

In addition, because suppressed secondary flow effectively, so the heating of unallowed pressure wall here also can not take place.Therefore, on the anchor ring that surrounds the interchanger heating surface, there is not a large amount of ash fall.

Though utilize and previously presentedly in ring, inject negative heat dust gas and can keep intra-annular pressure to be lower than the pressure of gas interior to a certain extent, but method of the present invention but plans to inject quench gas in ring, thereby the intra-annular gaseous tension is equaled or a little higher than gasifier unit and the interior gaseous tension of passage.

The temperature of dust-free gas is preferably 200-350 ℃, and more preferably less than 300 ℃.

Dust-free gas is preferably the part of gasifier unit gas products, and wherein this part gas products has removed dust in the downstream of described gasifying reactor, for example the dustless product gas that obtains in the solids removal district.Because the dustless product gas of this strand also is preferably used as quench gas, therefore have been found that combination provides dust-free gas and provides dust-free gas to the cooling channel to annular space is favourable.In this preferred embodiment, providing the evaluation method selecting optimal equipment of quench gas to be furnished with to the cooling channel provides the gas discharge outlet of quench gas and the gas discharge outlet of quench gas is provided to annular space.Have been found that by in the described equipment that quench gas is provided, providing enough perforates, can realize stable and operation reliably.Under given quench gas stress level and the stress level in the cooling channel, those skilled in the art can determine the area of perforate at an easy rate.

In a preferred embodiment, for the hot product gas of water conservancy diversion in the cooling channel, any sliding point that exists in the cooling channel is all by hermetic seal.According to method of the present invention, introduce ring because be used for pressure compensated quench gas from the quenching unit between gasifying reactor and quench tube, so pressure compensation is independent of the function of sliding point.

In this manner, pressure compensation also is independent of other two kinds of functions, the function that promptly expands and components apart function of sliding point.On the less differential expansion surface between each pressure wall and each cooling-part, preferably one or more gas shields can be set, thereby can ignore second function of a large amount of differential expansion on compensation is in parts at sliding point the axial direction due.

In addition, it also is useful having the ring that adds the refrigerative hot gas in syngas cooler, and described ring is limited by at least one heat exchanger surface and its pressure wall of encirclement, and its ring to the adding quench gas is airtight.

The invention still further relates to a kind of gasification reactor vessels of prolongation, this reactor vessel can be used in above-mentioned method, and it comprises: gasifier unit; Discharge from reactor by the negative heat dust gas product of this passage gasifier unit the cooling channel of coaxial arrangement; With the downstream that is positioned at described gasifier unit for negative heat dust gas product provides the equipment of quench gas, wherein also exist for the equipment that annular space between reactor vessel wall and cooling channel provides dust-free gas.Provide the evaluation method selecting optimal equipment of quench gas to be furnished with most of quench gass are offered the gas discharge outlet of cooling channel and a small amount of quench gas offered the gas discharge outlet of annular space.Provide the equipment of quench gas to be generally hole (bleeding opening), its size decision flows to the gas volume of quench tube and ring respectively.

The cooling channel is preferably provided with sliding point, its with respect to the hot gas of water conservancy diversion in the cooling channel by hermetic seal.

In the cooling channel in described quench gas feeding unit downstream, preferably have one or more sliding points.These sliding points are between two cooled channel segments faces and/or in the end of cooling channel.Being used for the annular barrier of enclosed annular space is preferably placed at the downstream of described sliding point.

It also is useful that further sliding point is provided on the connecting passage face, and for application component separation function better on the face of sliding point, this sliding point preferably is associated with the extension of pressure shield.

As noted earlier, in known carbon gasification device, cool down in order further to make gas (product gas), at least one interchanger heating surface that is surrounded by pressure wall links to each other with the downstream of cooling channel.In this connection, usefully between the heating surface of cooling channel and interchanger, be equipped with sliding point, usefully be used for sealing upstream or the downstream that the annular barrier that encircles in the sliding point downstream is positioned at the interchanger heating surface in addition.

Usually be applied in several heating surface that gas side connects each other successively, and these heating surface are surrounded by same pressure wall.Pressure compensation preferably occurs between the two following: the gas interior in the interchanger heating surface and with in the past between the ring that the negative dirt hot gas that cools down on the interchanger heating surface surrounds.Owing to compare significantly lower temperature with the temperature on the hot gas flow-guiding channel face, in ring so the sedimentation of secondary flow and consequent a large amount of dusts no longer takes place.

Under the situation of using a plurality of interchanger heating surface, usefully between two adjacent heating surface, insert airtight sliding point at least.

Below in conjunction with accompanying drawing the present invention is described, in the accompanying drawings:

Fig. 1 has represented an embodiment of carbon gasification device, wherein gasifier unit is arranged in first pressurized vessel (gasifying reactor), and the interchanger heating surface is arranged in second pressurized vessel (syngas cooler), and wherein two pressurized vessels are continuous by the connecting passage (so-called pipeline) of a rising; With

Fig. 2 has represented compared to Figure 1 to have another embodiment of the connecting passage (pipeline) of inclination.

The gasification installation of describing among Fig. 1 is made up of gasifying reactor 1, connecting tube 2 and syngas cooler 3.Gasifying reactor 1 comprises the pressurized vessel 4 of vertical orientated prolongation, is furnished with cooling channel 5,7 and quench gas in this pressurized vessel unit 6 is provided.For gasifier unit 8 provides carbon raw material such as comminuted coal.At 9 places is quench gas generator 6 charging quench gas Q.Hot product gas HG behind the chilling flows in the cooled channel part 7 in quench gas generator 6 downstreams.The cooling channel is furnished with cooling surface.These cooling surfaces are preferably a plurality of tube banks, and water coolant flows by tube bank.A kind of preferred cooling surface is a disclosed septum wall in US-A-4859213.

The lower end of gasifying reactor 1 is furnished with gas shield 10.In addition, slag S discharges in the lower end 11 of gasifying reactor 1.Pressurized vessel 4 is made up of lower member 4a and the upper member 4b that has angle flange 4c.Pressure shield 12 is coupled.Syngas cooler 3 comprises the pressurized vessel of being made up of container parts 13a, 13b, 13c 13.Described pressurized vessel parts 13 comprise an angle flange 13d of orientation downwards, and described angle flange 13d determines connecting passage 2 with flange 4c and pressure shield 12.In gas cooler 3, three interchanger heating surface 14 are arranged, and from the flow direction of hot gas HG, their arranged superposed.Heating surface only schematically provides, and can be the form of heating surface with cold gas pod 14a and straight or curved internals 14b.In the embodiment illustrated, the gas flow guiding cover 14a of the heating surface on top is joined together to form gas flow guiding cover 15 on two, and this gas flow guiding cover 15 links to each other with the gas flow guiding cover 17 of the heating surface of bottom by airtight sliding point 16.

Connection between cooled channel part 7 and the gas pod 15 realizes by hot gas flow-guiding channel 18, this hot gas flow-guiding channel 18 extends in the pressurized vessel 4 at its curved part 18a, pass through pressure shield 12 and flange 13d with straight-tube portion 18b, and form gas drift chamber 18c in its final section.

Gas flow guiding passage 18 is furnished with sliding point 19 at its inlet end, and it slides with respect to quench tube 7, and described quench tube 7 is furnished with the position 7a of amplification at its exit end.This amplification is represented in the drawings as a simple taper.

The relative terminal of cooled channel part 7 and gas flow-guiding channel 18 all is furnished with loop

expansion pipe fixer

20 and 21, have a circle bench 22 to extend between the two, thereby sliding point 19 is with respect to the hot gas hermetic seal from the effusive heat of quench tube.In the connecting passage 2 in the face of pressure shield 12, be furnished with another sliding point 23 between two part S1 of gas flow guiding passage 18 and S2, wherein the S1 part has one at its exit end and amplifies the position.Sliding point 23 matches at design aspect and sliding point 19.

Between the inlet of the exit end of the gas flow guiding passage 18 in gas cooler 3 and gas pod 15, is furnished with another sliding point 24, it is different from sliding point 19 and 23 in design, difference is, see along the gas flow direction, amplify position 15a and be not arranged on the exit end of gas flow guiding passage 18, and be arranged on the inlet end of pod 15.Sliding point 15 matches at design aspect and sliding point 24.

Also the amplification position of sliding point 19 and 23 can be arranged on other gas flow guiding element.Equally, at sliding

point

16 and 24 places, can provide at the downstream in gas flow guiding district inlet end and amplify the position.

As shown in Figure 1, gasifying reactor 5, cooled channel part 7, gas flow guiding passage 18, gas flow guiding cover 15 and gas pod 17 are surrounded by pressurized vessel 4, pressure shield 12 and pressurized vessel 13 determined rings 25.This ring limits by the annular barrier 10 in the gasifier unit 1 on the one hand, be further divided into two partial ring 25a and 25b by annular barrier 26 on the other hand, and described annular barrier 26 is between sliding point 24 and top heating surface 14.

Because with respect to the negative dirt hot gas of water conservancy diversion in the gas internals, sliding

point

19,23 and 24 is hermetic seals, so in routine operation, do not have negative dirt hot gas and can enter ring 25a.

For the gas interior for gasifying reactor 1, cooled channel part 7 and gas flow-guiding channel 18 provides pressure compensation, in ring 25a, inject quench gas Q, described quench gas enters ring 25a from quench gas generator 6 by outlet perforate 27.Select the structure of outlet perforate 27 according to pressure, thereby pressure among the ring 25a is equaled or the air pressure of a little higher than gas interior hot gas.Because quench gas enters ring with the temperature (as 250 ℃) more much lower than the temperature (as 900 ℃) of the hot gas in the gas flow guiding passage 18, so the critical heating of each pressure wall can not take place.Because quench gas does not contain dust, the sedimentation of dust can not take place.

The ring 25b in annular barrier 26 downstreams uses from gas flow guiding cover 17 lower ends effusive part refrigerative hot gas and inflates backward and upwards, and wherein said hot gas is cooled to 300-250 ℃.

Because ring 25b injects be still contain dust but obvious colder gas, so can not take place because the rising of hot gas logistics and the secondary flow that causes with postcooling.

Shown in the dotted line of Fig. 1, pressure shield 12 can have one to amplify position 12a, and its permission enters sliding point 23 in order to check purpose by inlet drilling 12b.

Also annular barrier 26 can be set in the downstream of a heating surface 14, and therefore amplify ring 25a.Annular barrier 26 is set above sliding point 24 also be it is contemplated that.

The embodiment of Fig. 2 is different from the embodiment of Fig. 1 aspect following: the connecting passage between gasifier 1 and the gas cooler 3 is not to rise but descend.Rise the having of Fig. 1 and Fig. 2 or two kinds of decline connecting passage 12 design is by Fig. 1 of US-A-4859214 and Fig. 2 as can be known usually.In addition, in the embodiment of Fig. 2, can be provided with and amplify position 12a.Also can use other connecting passage, for example level or bending channel.

Therefore, in these two embodiments, hot gas can not injected by quench tube in any point of the ring of determining between each assembly and pressure wall 25, but injects cold air, promptly inject with the form of quench gas Q on the one hand, and inject with the hot gas that has cooled down on the other hand.For fear of the short circuit between quench gas and the hot gas that cools down, separate mutually with barrier in the space of inflation.From the flow direction of hot gas, the position of annular barrier can change.

Fig. 3 has described chilling in more detail unit 6 is provided.It is that chilling to Fig. 3 described in the US-A-4859213 and 3a provides the unit to carry out improved chilling the unit is provided that this chilling provides the unit.Improvements are to have added perforate 27, can enter annular space 25 by this perforate quench gas.Fig. 3 has also described the septum wall parts 45 of cooling channel 5 and 7, the perforate 53 and the service duct parts 9 of quench gas is provided for cooling channel 5 and 7.

Claims

1. the gasification process of a solid carbonaceous feed, wherein said gasification is implemented in the gasification reactor vessels of a prolongation, and described reactor vessel comprises: gasifier unit; Discharge from reactor by the negative heat dust gas product of this passage gasifier unit the cooling channel of coaxial arrangement; With the equipment that quench gas is provided for negative heat dust gas product in the downstream of described gasifier unit; Wherein provide dust-free gas with enough flows in the annular space between reactor vessel wall and cooling channel, thereby guarantee that not negative heat dust gas flows into described annular space from the cooling channel.

2. the described method of claim 1, wherein the pressure in the annular space is equal to or higher than the pressure in the cooling channel.

3. each method of claim 1-2, the temperature of wherein said dust-free gas is 200-350 ℃.

4. each method of claim 1-3, wherein said dust-free gas is the part of the gas products of gasifier unit, wherein this part gas has removed dust in the gasifying reactor downstream.

5. the method for claim 4, wherein said dust-free gas is the part of quench gas.

6. the method for claim 5, wherein providing the equipment of quench gas to be furnished with for the cooling channel provides the gas discharge outlet of quench gas and the gas discharge outlet of quench gas is provided for annular space.

7. the gasification reactor vessels of a prolongation comprises: gasifier unit; Discharge from reactor by the negative heat dust gas product of this passage gasifier unit the cooling channel of coaxial arrangement; Provide the equipment of quench gas with the downstream at described gasifier unit for bearing the heat dust gas product, the annular space between wherein also promising reactor vessel wall and the cooling channel provides the equipment of dust-free gas.

8. the reactor of claim 7, wherein providing the equipment of quench gas to be furnished with for the cooling channel provides the gas discharge outlet of quench gas and the gas discharge outlet of quench gas is provided for annular space.