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
  • C10J3/72—Other features
  • C10J3/82—Gas withdrawal means
  • C10J3/84—Gas withdrawal means with means for removing dust or tar from the gas
• • 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
  • C10J3/46—Gasification of granular or pulverulent flues in suspension
  • C10J3/54—Gasification of granular or pulverulent fuels by the Winkler technique, i.e. by fluidisation
• • 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
  • C10J3/46—Gasification of granular or pulverulent flues in suspension
  • C10J3/54—Gasification of granular or pulverulent fuels by the Winkler technique, i.e. by fluidisation
  • C10J3/56—Apparatus; Plants
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10K—PURIFYING OR MODIFYING THE CHEMICAL COMPOSITION OF COMBUSTIBLE GASES CONTAINING CARBON MONOXIDE
  • C10K1/00—Purifying combustible gases containing carbon monoxide
  • C10K1/02—Dust removal
  • C10K1/024—Dust removal by filtration
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10K—PURIFYING OR MODIFYING THE CHEMICAL COMPOSITION OF COMBUSTIBLE GASES CONTAINING CARBON MONOXIDE
  • C10K1/00—Purifying combustible gases containing carbon monoxide
  • C10K1/02—Dust removal
  • C10K1/026—Dust removal by centrifugal forces
• • 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
  • C10J2300/09—Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
  • C10J2300/0953—Gasifying agents
  • C10J2300/0973—Water
  • C10J2300/0976—Water as steam
• • 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
  • C10J2300/0983—Additives
• • 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
  • C10J2300/0983—Additives
  • C10J2300/0996—Calcium-containing inorganic materials, e.g. lime
• • 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
  • C10J2300/18—Details of the gasification process, e.g. loops, autothermal operation
  • C10J2300/1861—Heat exchange between at least two process streams
  • C10J2300/1884—Heat exchange between at least two process streams with one stream being synthesis gas

Definitions

• the invention relates to a method of producing a clean gas in a reaction zone by mixing hot air and steam with carbonaceous residue, adding hydrocarbon to release moisture ' and volatile and to have reacted volatile and carbon to CO and H 2 .
• the production of fuel gas from hydrocarbon like coal is operated at the present time by injecting cold reactants and/or steam into a gasifier and transferring a major portion of the sensible heat in the gasification products to a water/steam mixture. This is necessary to enable reliable operation of downstream gas cleaning equipment. Consequently the conversion of coal to the product gas in terms of the energy content is not maximized.
• one object of the invention is to provide a novel method and plant which maximizes the production of clean "reduced” gas from the feed hydrocarbon with minimal transfer of heat out of the involved system.
• the equipment necessary for performing the gas production consists mainly of three blocks, namely a gasifying device 3, a gas/solid heat exchanger 4 and an combined ash cooler/oxidizer 1 , 2.
• ambient air is introduced in the ash cooler 1.
• water is also introduced into the cooler at its cold end via water supply 10. This water is evaporated in the air stream during its travel through the cooling device.
• This device may be a gas/solid heat exchanger of the grid type or of the fluid bed type. The air is heated up to about 500-900°C. The lower value is chosen, if it is intended to have a catalytic reaction further downstream.
• the solids entering the cooler 1 at its hot side consist mainly of inert ash, carbon and of CaS and CaO. They have an inlet temperature of about 600°C and leave the cooler with a temperature of about 100°C.
• the size of the solids is at least approximately 500 ⁇ m which avoids particles being entrained with the air leaving the cooler at its hot end.
• an oxidizing sector 2 the unbumed carbon and CaS particles are first oxidized by the hot air/steam mixture into C0 2 and CaS0 4 .
• Other components of the hot material i.e. unoxidized gases like CO, H 2 S and COS as well as sulphided sorbents like CaS and FeS are also oxidized in this area. It might be that the unbumed carbon and CaS particles are also oxidized by the hot air/steam mixture into CaO and S0 2 .
• the air/steam mixture enters a reactor 3 via a hot air supply 21.
• the mixture can be introduced into the reactor on different levels.
• the reactor is an upright gasifier with a flow stream from bottom to top, the mixture is introduced at the bottom.
• the reactor is provided with two other inlets.
• the carbonaceous residue is char which is partially gasified coal. It enters the reactor 3 with a temperature of about 700°C. It reacts with the oxygen of the air/steam mixture to form C0 2 /CO and releases heat.
• the coal to be gasified Downstream of the char inlet, the coal to be gasified is introduced into the reactor 3.
• This coal can be either crushed or pulverized. Like the air, coal may be injected on different levels of the reactor.
• the same inlet is preferably used to introduce sulfur sorbent, which can be pulverized limestone or dolomite.
• Coal and sorbent may be transported by any suitable means, i.e. by steam; in a pre- ferred embodiment, the produced reduced gas itself transports the solids. If the coal is in form of crushed material with a size of approximately 6 mm, it can be fed by gravity.
• the adding of coal in the reactor results in a moisture and volatile release. A reaction of volatile and carbon occurs with the steam, the C0 2 and remaining 0 2 (if any) to form CO and H 2 .
• CaC0 3 is converted into CaO.
• the sulfur in the coal is converted mainly into H 2 S and in trace quantities into COS. Most of the H 2 S and COS react with CaO to form solid CaS.
• the calcium sorbent is present as CaS and CaO.
• a particulate separation device 11 Downstream the reactor a particulate separation device 11 is provided.
• This separator could be a cyclone designed to separate the predominant char from the remaining components. Since the size of the ash is typically smaller than 30 ⁇ m it will escape the cyclone, while the char, which is greater than 100 ⁇ m, will be retained in the cyclone.
• This separated char is returned via the supply line 20 into the reactor, while the remaining components, especially the reduced gas is forwarded to a gas cooler 4.
• the reduced gas is supposed to leave the gas cooler 4 with a temperature of about 200°C. Downstream the gas cooler a solids filter 5 is provided in the line 14 to remove from the gas fine ash and char, as well as CaS and CaO that has not been separated in the gas cooler 4. This filter is supposed to remove all the remaining solids from the gas.
• a further fan 17 is installed in the gas line 14, preferably on the clean side of the filter 5. Its purpose is to control the pressure in the system close to atmospheric conditions.
• a further gas cooler 18 may be provided in the gas line 14 downstream the fan 17, if a wet electrostatic participator has not been used upstream as a filtering element. To cool the gas down to 30°C, it is recommended to use a water spray cooler.
• the filter 5 could be a fabric filter, an electrostatic participator or a wet electrostatic participator.
• the use of the latter provides following advantages: beside the particulate removal a further cooling of the gas, the removal of ammonia, tar and hydrogen cyanide that might have been produced in the reactor 3.
• the further treatment of the solids removed from the filter 5 is a major feature of the present invention.
• the gas cooler 4 is a gas/solids heat exchanger and might be constituted of a series of cyclones. Therein solids and gas flow in a predominating counter- current manner.
• the minor part of cold solids fed into the gas cooler is taken from the exit of the filter 5 via feed line 22.
• As the size of the solids exiting the filter is smaller than 50 ⁇ m, they have to be size-enlarged in order to enable retention within the cyclones. This agglomeration occurs in a pelletizer 6, in which pellets having a size of approximately 1-5 mm are produced.
• the solids are introduced in the gas cooler 4, in which they are heated up to about 600°C. At the exit of the gas cooler, they are fed into the ash cooler 1 via the heated solids line 15a.
• the major part of cold solids to be fed into the gas cooler are solids exiting the ash cooler 1 being recycled unchanged into the gas cooler 4 via 13. This means that only the solids exiting the filter 5 have to be pelletized. This is based on the fact, that the size of the solids being cooled down in the ash cooler 1 is great enough to be retained in the gas cooler 4 while flowing through the series of cyclones. As shown in the drawing, accordingly both solids from filter 5 and from ash cooler 1 are separately introduced in the gas cooler. Moreover they each cross the gas cooler in a separate path being each heated up therein to about 600°C. The separate paths are maintained as a heated solids line 15, 15a throughout the further flow of this solids.
• the amount of the solids exiting the filter 5 and flowing through line 15a corresponds approximately to the amount of material to be disposed. Accordingly it is preferable to also keep separated by a partition this solids from the main solids flow in line 15 within its travel through the ash cooler 1 and to dispose it via the line 19.
• the invention may be illustrated in more detail with reference to a numerical example: it goes without saying that absolute values cannot be specified in connection with the said numerical values with regard to the dimensioning of the involved apparatus and in particular the reactor and the gas cooler, since absolute values are in any case not meaningful enough on account of their dependence on all too numerous parameters.
• the sole determining factor for the design is that minimal transfer of heat out of the involved system is realized.
• the amount of injected coal via line 7 be 19.5 kg/sec, the coal having a lower heating value of about 25 MJ/Kg and containing about 2.5 kg H 2 0.
• the amount of injected sulfur sorbent, i.e. limestone via line 8 be 3 kg/sec.
• Via a fan 16 about 45 kg/sec of air are sucked in the system. Water in the amount of 5 kg/sec is added at the cold side of the ash cooler via water supply 10. All these components are introduced under ambient conditions.
• the amount of circulated inert solids through the gas cooler 4 and the ash cooler 1 via path 13, 15 is about 75 kg/sec.
• the amount of solids captured at the exit of filter 5, pelletized and transported through the gas cooler and the ash cooler in an own path 15a and disposed via the line 19 is about 5.5 kg/sec. It is assumed that 0.5 kg/sec of this solids are burned out during oxidation in the ash cooler and flow as a gas into the reactor 3, thus remaining in the cycle.
• the reduced product gas downstream the fan 17 is at an amount of about 67.5 kg/sec, the gas having a heat value of 6.7 MJ/kg.
• a small amount of the product gas is kept in the system as a transportation means for the pulverized coal and sorbent.
• a small amount of the hydrocarbon i.e. coal might be injected in a burner located in the ash cooler. This feature allows a temperature control within the ash cooler.
• the sorbent i.e. limestone or dolomite might be injected into the ash cooler instead into the reactor 3. If this sorbent is pulverized, the size must be fine enough to be entrained by the air stream. Again CaC0 3 is converted into CaO; a small portion of unreacted CaO forms CaS0 4 with S0 2 in the ash cooler. This feature allows calcining the sorbent and providing a longer residence time for CaO inside the downstream reactor 3, which improves the sulfur capture.
• the air/steam mixture as well as the coal might be introduced into the reactor at several different locations, which allows a better temperature control inside the reactor and a still higher conversion efficiency.
• the invention is not restricted to the plant shown and described.
• the invention can be used irrespective of the type and design of the reactor.
• This reactor could be as well an apparatus with entrained flow, if a pulverized fuel is used or with fluidized bed, if crushed fuel is used.
• separating apparatus with moving bed could be used as well.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Industrial Gases (AREA)
• Treating Waste Gases (AREA)
• Gas Separation By Absorption (AREA)
• Electrostatic Separation (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8236217

Family Applications (1)

Country Status (5)

Cited By (1)

Families Citing this family (4)

Citations (6)

• 1998
  • 1998-07-29 EP EP98810727A patent/EP0976807A1/en not_active Withdrawn
• 1999
  • 1999-07-09 CN CN 99811260 patent/CN1319125A/zh active Pending
  • 1999-07-09 WO PCT/CH1999/000313 patent/WO2000006672A1/en not_active Application Discontinuation
  • 1999-07-09 EP EP99928984A patent/EP1105446A1/en not_active Withdrawn
  • 1999-07-09 JP JP2000562456A patent/JP2003527453A/ja active Pending
  • 1999-07-09 AU AU45984/99A patent/AU4598499A/en not_active Abandoned

Patent Citations (6)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events