Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
  • C10J3/00—Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
  • C10J3/02—Fixed-bed gasification of lump fuel
  • C10J3/20—Apparatus; Plants
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
  • C10J3/00—Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
  • C10J3/02—Fixed-bed gasification of lump fuel
  • C10J3/20—Apparatus; Plants
  • C10J3/22—Arrangements or dispositions of valves or flues
  • C10J3/24—Arrangements or dispositions of valves or flues to permit flow of gases or vapours other than upwardly through the fuel bed
  • C10J3/26—Arrangements or dispositions of valves or flues to permit flow of gases or vapours other than upwardly through the fuel bed downwardly
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
  • C10J3/00—Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
  • C10J3/72—Other features
  • C10J3/721—Multistage gasification, e.g. plural parallel or serial gasification stages
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
  • C10J2200/00—Details of gasification apparatus
  • C10J2200/09—Mechanical details of gasifiers not otherwise provided for, e.g. sealing means
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
  • C10J2300/00—Details of gasification processes
  • C10J2300/09—Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
  • C10J2300/0913—Carbonaceous raw material
  • C10J2300/0916—Biomass
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
  • C10J2300/00—Details of gasification processes
  • C10J2300/09—Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
  • C10J2300/0953—Gasifying agents
  • C10J2300/0956—Air or oxygen enriched air
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
  • C10J2300/00—Details of gasification processes
  • C10J2300/12—Heating the gasifier
  • C10J2300/1207—Heating the gasifier using pyrolysis gas as fuel
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
  • C10J2300/00—Details of gasification processes
  • C10J2300/12—Heating the gasifier
  • C10J2300/1215—Heating the gasifier using synthesis gas as fuel
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
  • C10J2300/00—Details of gasification processes
  • C10J2300/12—Heating the gasifier
  • C10J2300/1223—Heating the gasifier by burners
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/10—Process efficiency
  • Y02P20/129—Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines

Definitions

• the invention refers to three-stage gasifier, fixed bed, which has buffer zone of gaseous 5 flow between pyrolysis zone and combustion zone, which is used for solid carbonaceous materials gasification.
• the gasification is a thermochemical process that converts solid fuels into combustible gases.
• the successive proceedings which take place during the process are: 10 -Pyrolysis(>230°C).
• the humidity of the solid fuel is converted to vapor.
• the volatile components of the fuel are converted to gases, consisted mostly from tar and/or polycyclic aromatic hydrocarbons(C n H m ), carbon dioxide(CO 2 ), carbon monoxide(CO), methane(CH 4 ) and hydrogen(H 2 ).
• the solid residues are charcoal and ash.
• the glowing charcoal(C) is affected by vapor(H 2 O) and oxygen(0 2 ). 15 It is converted to gases, mostly hydrogen(H 2 ), carbon monoxide(CO) and carbon dioxide(CO 2 ).
• the mostly used reactors are fixed bed (cocurrent or countercurrent) and fluidized bed
• the fixed bed reactors are relatively simple fabrications and they are proper for small and 20 medium scale power, but the fluidized bed reactors are complex fabrications and they are applied for power >20MW.
• the air moves up-draught, having opposite direction from the fuel, namely enters directly to the hearth and is gradually converted to hot gas, which
• the air moves down-draught, having the same direction with the fuel, namely enters directly to the hearth but does not passes through the drying zone.
• the drying and the pyrolysis are mainly achieved from the radiation of the hearth.
• the tars which are produced at the pyrolysis zone are cracked effectively, because they pass
• the cocurrent gasifier gives gas with low concision of tars (0.025-0.100 g/Nm 3 ) referring to not trained gas. This gas, after cooling and particle separation is proper for use into internal combustion engines. Unfortunately, the low thermal exchange between hearth and drying
• the fixed bed of the pyrolysis reactor (2) seats on some type of moving grate for the removal of charcoal.
• the flue gas from the combustion of pyrolysis gases applies quite high temperature on the moving grate and therefore the charcoal removal system shall appear often damages.
• -The fixed bed of the gasification reactor (4) seats on some type of moving grate for the removal of ash.
• the gasification chamber (4) is a countercurrent reactor. The pieces of the charcoal fall from the bottom of the pyrolysis reactor (2) and lay on the top of the gasification bed (4). They contain harmful volatile residues (tars, dioxins) due to pyrolysis imperfections. Those volatiles are evaporated without thermal cracking.
• the producer gas shall have significant amount of harmful components.
• the material lock chamber (68) at figures 7and 12 and 15 manages the gaseous flow between the stages.
• the main and very serious disadvantage of this layout is that in blockage case of the gates (69) and (70) of the material lock chamber (68), the uncontrollable commixture of gas and air will create explosive gas-air mixture into the reactor.
• Viking Gasifier This is a three stage, laboratory scale gasifier without problems of gaseous flow management.
• the fuel is imported to the pyrolysis chamber and there, using external heating at the wall of the chamber, takes place thermochemical separation between charcoal and volatiles-vapor.
• the fragments of the fuel pass through a high temperature air intake zone and when this mixture passes this zone, large fractions of tars and dioxins are burned and/or cracked. After this, the gasification takes place at the glowing charcoal bed.
• Viking Gasifier cannot operate at industrial scale.
• the external heating at the wall of the pyrolysis chamber eliminates the problems of gaseous flow management, but simultaneously limits dramatically the power records of the plant.
• the multistage gasifiers have separate stages for pyrolysis, combustion of pyrolysis gases and gasification of charcoal. Quite enough stage and method possible combinations can compose a multistage gasifier, giving the corresponding advantages and/or disadvantages.
• the present device aims to work at the gaseous flow management between pyrolysis, combustion of pyrolysis gases and gasification of charcoal in order to create a fixed bed gasifier which shall combine the following characteristics:
• the gasifier shall not expose its moving mechanical parts at temperatures above 750 0 C.
• this is achieved by a three-stage gasifier, fixed bed, which has buffer zone of gaseous flow between pyrolysis zone and combustion zone.
• This gasifier is composed from three separate stages, which make pyrolysis (first stage), combustion of pyrolysis gases (second stage) and gasification of charcoal (third stage).
• the above stages are placed at vertical position, without mechanical separation between them.
• the combustion air of the pyrolysis zone moves up-draught, in reverse direction from the pyrolysis gases combustion flue gas, which moves down-draught.
• We separate the gaseous flow by placing buffer zone between pyrolysis zone and gasification zone.
• the inlet of the combustion air of the pyrolysis zone is placed at the upper place of the buffer zone and the expansion of the pyrolysis gases combustion flue gas at the lower place.
• the flow of the preheated air, which enters at the upper place of the buffer zone, is divided in two streams, by using the proper rotation settings at the pumps of the gasifier.
• the up- draught stream of the preheated air is cooling the pyrolysis charcoal removing grate and feeds the pyrolysis bed.
• the down-draught stream of the preheated air feeds the gasification bed.
• the buffer zone allows the charcoal which is produced at the first stage to pass and fall without stoppage into the third stage.
• the down-draught stream of the preheated air when pass through the buffer zone, acts as an isolation curtain between first and second stage.
• the pyrolysis zone cannot work effectively. In this case we reverse the flow into the buffer zone, in order that part of the flue gas to feed the pyrolysis bed with heat. Also, when we feed the gasifier with extremely very wet fuel, we provide to the combustion torch additional external supply of gas fuel (natural gas or propane), in order to have enough power for the heating of the huge percentage of vapor which exists into the pyrolysis gases.
• gas fuel natural gas or propane
• the pyrolysis gas pump collects the most of the harmful volatiles (tars, dioxins) derived from the pyrolysis zone. Crossing the flame of the burning torch, those harmful volatiles are burned and/or cracked. The pieces of the charcoal, which fall from the first stage, contain also harmful volatile residues (tars, dioxins) due to pyrolysis imperfections. Acting as an additional cleaning stage, the glowing charcoal bed reduces and/or cracks the harmful residues derived from pyrolysis and combustion. So, at the end of the process, we have gas and ash free of harmful residues.
• Figure 1 shows the normal operation of the three-stage gasifier, fixed bed, which has buffer zone of gaseous flow between pyrolysis zone and combustion zone.
• the pyrolysis zone (1) is a countercurrent reactor, fixed bed.
• the pyrolysis zone (1) is imported, through the material feeding system (4), the under process fuel and which is held from the grate (5).
• the pump (BPA) and the heat exchanger (EPA) is offered preheated air ( ⁇ 400°C).
• the preheated air (-400 0 C) is divided in two streams.
• the up-draught stream (13) is cooling the grate (5) and feeds the pyrolysis bed (1).
• the down-draught stream (14) pass through the buffer zone, acts as an isolation curtain between pyrolysis zone (1) and combustion zone (2), pass through the combustion zone (2) and feeds the gasification bed (15).
• the up-draught stream (13) creates the following layers into the pyrolysis zone (1): -Burning Hearth (7). It is achieved partial combustion of the charcoal, which gives the energy for the reactions at the above stacks of material. The rest charcoal and the ash are detached by moving the grate (5), they fall downwards, they pass through the buffer zone
• the solid fragment (charcoal, ash) falls to the reduction zone (8) while the hot gases rise through the new incoming fuel (10) and they dry it.
• the humidity of the fuel is converted to vapor, which departs together with the rest gases.
• the pyrolysis gases (PG) derived from the layers of hearth (7), reduction (8), distillation (9) and drying (10) is a mixture from CO, CO 2 , CH 4 , C n H m , H 2 , H 2 O ⁇ N 2 .
• the pyrolysis gases (PG) are sucked through the pyrolysis gas pump (BPG) and in cascade, through the pyrolysis gas duct (11), they are imported into the torch (12).
• preheated air ⁇ 550°C
• the torch (12) blends the pyrolysis gases (PG) with the preheated air ( ⁇ 550°C) and creates flame 1100 0 C- 1200 0 C.
• the flue gas (16) expands into the space of the combustion zone (2) and trends down-draught, in order to come together with the gasification bed (15).
• the gasification zone (3) is a cocurrent reactor, fixed bed.
• the gasification bed (15) of the cocurrent reactor (3) seats on the ash discharge system (17).
• the gasification bed (15) operates with temperature shift from 1100°C-1200 0 C (upper side) to 700°C-750°C (lower side), due to the endothermic gasification reactions.
• the mechanical parts of the ash discharge system (17) are not under significant thermal burden.
• the glowing charcoal bed (15) reduces and/or cracks the harmful residues derived from pyrolysis (1) and combustion (2).
• the final producer gas has low conciseness in tars (0.025g/Nm 3 ) and it is rich in H 2 and CO.
• the pyrolysis zone cannot produce sufficient quantities of charcoal and combustible pyrolysis gases. In this case we reverse the flow into the buffer zone, in order that part of the flue gas to feed the pyrolysis bed by heat.
• figure 2 we show (using equivalent symbols and descriptions with figure 1) the reversed operation of the buffer zone, which is achieved by modification of the normal operation, in order to gasify very wet and/or poor thermally fuel.
• the pyrolysis zone (1), the combustion zone (2), the gasification zone (3), material feeding system (4) and the grate (5) are as they have been described in normal operation.
• the flue gas from the torch (12) is divided in two streams.
• the up-draught stream (22) passes through the buffer zone (20) and enforces additional heat to the pyrolysis bed (1).
• the down-draught stream (23) feeds the gasification bed (15).
• the up-draught flue gas stream (22) and the up-draught air stream (24) create the following layers into the pyrolysis zone (1):
• PG pyrolysis gases
• BPG pyrolysis gas pump
• pyrolysis gas duct (11) pyrolysis gas duct (11) and the torch (12) are as they have been described in normal operation.
• the automatic control of the pyrolysis zone (1) is like in normal operation.
• the torch (12) through the pump (BCA) and the heat exchanger (ECA), is offered preheated air (-550 0 C).
• the torch (12) blends the pyrolysis gases (PG) with the preheated air (-550 0 C) and creates flame 1100°C-1200 0 C.
• the flue gas of the torch expands into the space of the combustion zone (2) and is divided in up-draught stream (22) and down-draught stream (23).
• the gasification zone (3), the gasification fixed bed (15) and the ash discharge system (17) are as they have been described in normal operation.
• the output of the gasification zone (18), the heat exchangers (ECA) and (EPA), the particle cleaning and cooling gear (19) and the producer gas pump (BGO) are as they have been described in normal operation.
• figure 2 we show the emergency operation of the invention, which is achieved by modification of the reversed operation, in order to gasify extremely very wet fuel.
• gas fuel natural gas or propane
• PG pyrolysis gases
• the emergency operation of the invention gasifies extremely very wet fuel. Also, by the same way, the system makes cold startup.
• the document PCT/GR2007/000017 contains figure 3 and claim 4, which have date of application the 06 March 2007 and are the concept of the present invention. At the document PCT/GR2007/000017 the recommended support of the concept of the present invention does not exists. So, in order to support correctly the concept of the invention, the present document is submitted.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Organic Chemistry (AREA)
• Gasification And Melting Of Waste (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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• 2008
  • 2008-03-04 EP EP08719101A patent/EP2126008A2/de not_active Ceased
  • 2008-03-04 WO PCT/GR2008/000017 patent/WO2008107727A2/en active Application Filing

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