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
  • C10J3/06—Continuous processes
  • C10J3/08—Continuous processes with ash-removal in liquid state
• • 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
  • C10J3/723—Controlling or regulating the gasification process
• • 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
  • C10J3/74—Construction of shells or jackets
  • C10J3/76—Water jackets; Steam boiler-jackets
• • 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
  • C10K3/00—Modifying the chemical composition of combustible gases containing carbon monoxide to produce an improved fuel, e.g. one of different calorific value, which may be free from carbon monoxide
  • C10K3/001—Modifying the chemical composition of combustible gases containing carbon monoxide to produce an improved fuel, e.g. one of different calorific value, which may be free from carbon monoxide by thermal treatment
  • C10K3/003—Reducing the tar content
  • C10K3/005—Reducing the tar content by partial oxidation
• • 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
  • C10J2300/0946—Waste, e.g. MSW, tires, glass, tar sand, peat, paper, lignite, oil shale
• • 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
  • C10J2300/0959—Oxygen
• • 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
  • C10J2300/0969—Carbon dioxide

Definitions

• the present invention concerns a method and equipment to produce a syngas from wastes, preferably industrial or municipal wastes and their deliverables.
• the invention relates to a method and equipment design to produce synthesis gas which, when used as feedstock for Fisher-Tropsch, methanol or ammonia plants, will enable to substitute natural gas or other hydrocarbons with waste or waste derived fuel (also known as RDF, standing for refuse derived fuel).
• waste or waste derived fuel also known as RDF, standing for refuse derived fuel
• Such approach is intended to save resources, mainly hydrocarbons, and minimize emissions and pollution, and consequently protect the environment also in terms of CO 2 emissions.
• a proper gasification reactor needs to be designed for such a conversion in order to adhere to the requirements imposed on the syngas composition to be used for a subsequent production of chemicals, requirements quite different from the use of such a syngas as fuel.
• - slag temperature at the bottom of gasification reactor has to be high enough, 1400-1600°C, in order to maintain the slag in a liquid phase with a carbon content of less than 1%;
• the reactor design is preferably standardized for a specific capacity through modular approach. Product capacity will be achieved by multiple reactors working in parallel.
• Another object of this invention is to minimize emissions associated with waste disposal. Another object of this invention is to recycle the waste carbon matrix into valuable products, such as urea, methanol, bio-fuels, capturing the CO2 otherwise emitted by these plants.
• Yet another object of this invention is to provide a cost effective method to make chemicals.
• a further object of this invention is to provide a much cleaner and more uniform syngas composition than current processes provide.
• a further aim of the invention is that said method and equipment to produce a syngas from wastes can be realised with substantially limited costs, as far as both the construction and the operative costs are concerned.
• Not last aim of the invention is that of realising a method and equipment to produce a syngas from wastes being substantially simple, safe and reliable.
• - oxygen is injected at the bottom of said fixed bed to react with said wastes in an oxidation reaction to give a syngas, the temperature of the bottom of said fixed bed being maintained in a range between 1400 and 2000°C, preferably between 1400 and 1600°C, to form a melting area at the bottom of said fixed bed, where melting of inert and metal compounds contained in said wastes is obtained;
• a stabilizing area is provided at the top of said reactor, where the temperature ranges from 1050 to 1200°C;
• the temperature profile at the bottom and along the height of said reactor is controlled by injection of an inert gas flow at the bottom of said fixed bed, together with oxygen.
• natural gas is injected together with oxygen, at the bottom of said fixed bed and/or above said fixed bed.
• oxygen is injected in a plurality of injection points.
• said inert gas can be CO2.
• It is a second specific object of the present invention a n equipment to produce a syngas from wastes, preferably industrial or municipal wastes, according to the method previously defined, comprising a vertical type cylindrical fixed bed reactor with an internal lining with refractory and double steel walls with internal cooling water between the wails.
• a fixed bed of wastes is provided inside said reactor, the height of said fixed bed being set to a level apt to achieve a temperature at its top around 800°C.
• said equipment to produce a syngas from wastes comprises a plurality of lances for O 2 injection, said lances comprising two coaxial conduits, surrounded by a shell for a cooling fluid.
• FIG. 1A shows a schematic lateral sectional view of a reactor according the present invention, together with the temperature profile along the reactor,
• figure 1 B shows a schematic plan sectional view of the reactor of figure 1A
• FIG. 2 shows a schematic lateral sectional view of a particular portion of the reactor of figures 1A and 1 B, showing the temperature distribution of the fixed bed of wastes in proximity of an oxygen injection lance,
• figure 3 shows a schematic plan sectional view of the reactor of figure 1A, together with the temperature profile at the bottom of the reactor before control,
• FIG. 4 shows a schematic lateral sectional view of a particular portion of the reactor of figures 1A and 1B, showing the temperature distribution of the fixed bed of wastes in proximity of an inert gas injection lance,
• figure 5 shows a schematic plan sectional view of the reactor of figure 1 A, together with the temperature profile at the bottom of the reactor after control, and
• FIG. 6 shows a schematic lateral sectional view of the reactor of figures 1A and 1B, together with a schematic view of the control architecture.
• a vertical type cylindrical fixed bed reactor 10 is required.
• the reactor design has an internal lining 11 with special refractory and double steel walls 12 with internal cooling water 13 between the walls 12 (Jacket Cooling system) as safety measure.
• the required process temperature distribution is the following.
• the temperature at the bottom 14 of the reactor 10 shall be 1600°C to achieve the melting process of the inert and metal compounds inevitably present in the feedstock. Higher temperature is unnecessary for most of household and industrial waste and would cause only additional wearing of the refractory.
• the height of the bed 14 is set to a level suitable to achieve a temperature at its top around 800°C, the minimum temperature needed for the carrying out of most of the gasifying process.
• oxygen is injected in the reactor 10 by means of a set of lances 15 arranged radially as shown in Figure 1B.
• the amount of oxygen injected at the bottom of the reactor 10 is in relation with the waste composition and controls the system throughput.
• the process temperature profile is a result not so controllable by the oxygen amount.
• an amount of natural gas can be injected through a second channel 20 of the oxygen lances 15.
• This channel is used also for the reactor warm up and a minimum flow must be kept in any case to preserve from clogging caused by the melted inert (purging gas).
• Oxygen injected by the lances 15 impacts on the material that forms the bed 14 and, despite the high speed, is partially turned back. It reacts with violence in proximity of the refractory 11 , especially in presence of natural gas. As shown in figure 2, this causes a non uniform distribution of the temperature, with overheated zones on the refractory lining 1 around the heads of the lances 15, where the temperature can easily exceed 2000°C. This effect is worsened by high LHV material that causes a general increasing of the temperatures at the bottom of the reactor 0 and generally a more compact and difficult to penetrate bed 14. The resulting temperature profile in the cross-sectional area of the reactor 10 is shown in figure 3.
• a inert gas flow can be used.
• a small amount of inert gas at ambient temperature is introduced at low speed instead of the purging natural gas, which creates a cushion around the lances heads in order to decrease the local temperature.
• the inert gas amount can be increased to create a wider cooling effect to stabilize the temperature profile.
• Table 1 shows the effect of CO2 injection in case of a high calorific waste.
• Case 1 represents the condition without inert flow
• Case 2 with low amount of CO 2 (cushion effect only)
• Case 3 with CO2 amount set to reduce the calculated bottom temperature to the required working condition.
• the control of the reactor's bottom temperature is carried out by means of a computerized system (fuzzy logic) that takes in account the following parameters:
• the operator can select if to activate or deactivate the system and the strength of intervention (wall protection or process temperature reduction).
• the control of the reactor's top temperature is carried out by means of a computerized PID (Proportional Integral Derivative) controller that takes into account the following parameters:
• the system acts on the natural gas and oxygen injection by means of motorized valves.
• the operator can select if to use only the syngas combustion to increase the temperature or inject natural gas.
• This second option is used in case of need to preserve the hydrogen content of the syngas, especially in case of low LHV feedstock.

Applications Claiming Priority (2)

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Family Cites Families (7)

• 2016
  • 2016-10-07 IT IT102016000100814A patent/IT201600100814A1/it unknown
• 2017
  • 2017-10-09 WO PCT/IT2017/000220 patent/WO2018066013A1/en active Search and Examination
  • 2017-10-09 EP EP17825978.4A patent/EP3523401A1/de active Pending

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