Abstract:
The present specification describes and claims a method and apparatus for use in cooling the solid residue of gasification of a reactor operated at a pressure above atmospheric for the gasification of carbonaceous materials. The residue of gasification is conducted out of the reactor into a cooling apparatus located therebelow and flows through the cooling apparatus from the top to the bottom thereof. A cooling liquid is introduced into the solid residue in the upper region of the cooling apparatus and is metered such that the greater portion of the heat contained in the residue is eliminated in the form of heat of vaporization, sensible heat and chemical binding energy with the resultant steam and reaction products produced. The remaining residual heat which corresponds to the difference between the desired final temperature and the temperature after cooling by the liquid, is eliminated by a gas blown into the bottom region of the cooling apparatus and/or by indirect heat exchange.
Abstract:
An improved valve apparatus for the introduction of finely divided coal solids into a vessel in a controlled manner is disclosed. The disclosed apparatus includes substantially vertical and horizontal conduits interconnected to provide a generally continuous L-shaped flow path therethrough. Gas is introduced directly into the bottom portion of the vertical conduit upstream from the point where the vertical conduit and horizontal conduit interconnect. The flow rate of the gas introduced into the vertical conduit is controlled to adjust the amount of coal solids discharged from the discharge end of the horizontal conduit.
Abstract:
A process for converting a finely divided carbonaceous material, particularly coal, to a fuel gas. A finely divided or pulverized carbonaceous feed material, such as coal, is pretreated at a temperature of about 700.degree. - 800.degree. F in order to destroy the caking properties of a caking coal feed in a fluidized pretreatment zone, or, alternatively to dry a non-caking coal feed. The pretreated coal is passed from a pretreatment zone to a gasification zone wherein the carbonaceous feed material or coal is maintained as a fluid bed at selected conditions for converting the pretreated material to ash and a gaseous mixture. During the pretreatment of the feed material, hot off gases are formed and the hot off gases, which generally comprise steam, tars, oils, and carbonaceous fines, are passed from the pretreatment zone to the underside of the fluid bed in the gasification zone. The steam contained in the off gases is reacted with the coal in the fluidized bed in the gasification zone for converting the coal feed material to ash and the fuel gas product. The off gases also provide heat for maintaining the desired temperature conditions in the gasification zone. The tars and oils in the off gases are substantially destroyed during passage upwardly through the fluidized bed in the gasification zone. The fines in the off gases are converted by the gasification reaction in the gasification zone to form a part of the fuel gas and the ash. The fuel gas is withdrawn from the upper portion of the gasification zone and ash is withdrawn from the bottom of the gasification zone.
Abstract:
A fluidized bed gasification system which comprises a fluidized bed gasification reactor having a bottom ash discharge outlet below the reactor, wherein an L-valve is used to control the rate of bottom ash discharge. The L-valve uses an aeration port located on distal side of the L-valve vertical pipe at a location that is above the center line of the horizontal pipe. Also provided are methods of controlling the bottom ash discharge as well the fluidized reaction bed height of the system.
Abstract:
Gasification of carbon-containing raw material into gasified gas and recovery of CO2 are enabled at the same pressure throughout a system.Provided are a hydration tower 1 for performing hydration reaction by contact of CaO with water vapor while keeping at a predetermined pressure and a temperature at or below an upper limit for production of Ca(OH)2; a gasification reactor 2 with a water removal section 2a for dehydration of Ca(OH)2 introduced through heating to obtain highly active CaO and with a gasification section 2b for production of char through reaction of a raw material with water vapor and production of gasified gas through gasification of the char, CO2 being absorbed by CaO from the section 2a to produce CaCO3, heat of reaction at that time being used for the gasification of the raw material, the gasified gas being used as a heat source for the dehydration in the section 2a; and an absorbent regeneration tower 3 in which, in the presence of the char-containing CaCO3 from the section 2b, CO2, water vapor and oxygen, CaCO3 is calcined with heat of combustion of the char to separate it into CO2 and CaO, the resultant CaO being supplied to the hydration tower 1. The pressure in the reactor 2 and in the tower 3 connected to the tower 1 is the same as pressure in the tower 1.
Abstract:
Disclosed are cooling and depressurization system equipment, arrangement and methods to cool solid particles from a coal gasifier operating at high temperature and pressure. Ash from the coal needs to be continuously withdrawn from a circulating fluidized bed gasifier to maintain the solids inventory in the gasifier. The system disclosed enables use of conventional materials of construction for heat transfer surfaces. The supports for the cooling surfaces are located on the lower temperature upper section of the primary cooler. The cooled solids along with the fluidizing gas exits the primary cooler to a secondary receiving vessel where the solids can be further cooled by conventional means. The fluidizing and entrained gas entering the secondary vessel is filtered and vented through a vent pressure control valve. The column of cooled solids in the secondary vessel is depressurized by a continuous depressurization system to low pressures which are sufficient for conveying the solids to silos for disposal. The system and methods proposed are equally applicable to many high temperature, high pressure processes that require cooling and depressurization of process solids.
Abstract:
The present invention relates to a fluidized bed reactor system made up of at least two fluidized bed reactors, comprising at least one main reactor (1) in the form of a circulating fluidized bed and a secondary reactor (2) in the form of a circulating fluidized bed, and also a particle line comprising a particle separator for transporting fluidized bed particles from the main reactor into the secondary reactor, characterized in that, in the lower region of the respective reactor, a line (10) connects the secondary reactor (2) to the main reactor (1) for transporting fluidized bed particles.
Abstract:
The invention provides a system designed for the complete conversion of carbonaceous feedstock into syngas and slag. The system comprises a primary chamber for the volatilization of feedstock generating a primary chamber gas (an offgas); a secondary chamber for the further conversion of processed feedstock to a secondary chamber gas (a syngas) and a residue; a gas-reformulating zone for processing gas generated within one or more of the chambers; and a melting chamber for vitrifying residue. The primary chamber comprises direct or indirect feedstock additive capabilities in order to adjust the carbon content of the feedstock. The system also comprises a control system for use with the gasification system to monitor and regulate the different stages of the process to ensure the efficient and complete conversion of the carbonaceous feedstock into a syngas product.
Abstract:
An improved system and method is provided for operating a parallel entrainment fluidized bed gasifier system. A first aspect of the present invention relates to a method for reducing ash agglomeration in a parallel entrainment fluidized bed gasifier/combustor system by adding a quantity of MgO to the feedstock used in the gasifier/combustor system. A second aspect of the present invention relates to an apparatus and method for reducing erosion at piping bends in fluidized particulate piping systems which utilizes sand retention cavities positioned to receive and retain a portion of the fluidized particulate. A third aspect of the present invention relates to an apparatus and method for facilitating the flow of sand and char fragments from a first compartment to a second compartment while minimizing the flow of gases between the first and second compartments.
Abstract:
In this process for working up RESH or shredder light fractions, the RESH or shredder light fractions are charged into a fluidized bed gasifier. Hot wind or combustion offgases having a temperature above 450° C. are blown into the fluidized bed through nozzles while forming a counterflow grinding space. CaCO3 is introduced into the fluidized bed and calcined in the grinding space to effect disintegration.