Abstract:
A coal or carbonaceous material upgrading process for power station use, the process comprising a number of steps. First comminuting the coal or carbonaceous to a comminuted material. Second pre-treating the comminuted coal with a pulsing single frequency microwave and vacuum to reduce its water and oxygen content; the pre-treating stage being carried out at a temperature of up to 180 C Third, treating the pre-treated comminuted material with a pulsing single frequency microwave energy under vacuum to optimize the volatile organic materials; the treatment stage being carried out at a temperature of up to 350 C. Next pyrolyzing the treated coal with a pulsing single frequency microwave and vacuum to produce a hot gas and a solid carbon residue; the pyrolyzing stage is carried out at a temperature of up to 720 C. The solid carbon residue can then be separated from the hot gas, the volatile organic materials condensed to produce a liquid hydrocarbon product and a gas product, and the solid material and the gas product fed to a power station to produce electricity therefrom. The microwave energy applied at each of the stages has a single frequency of 100 megahertz to 300 gigahertz, has circular polarisation, and is pulsed at a frequency of 2 to 50 kilohertz. The pre-treatment step, the treatment step, and the pyrolysis step can be done under vacuum
Abstract:
According to a method for drying fuels in the form of dust, particularly to be fed to a gasification process, such as coal, petroleum coke, biological waste, or the like, wherein the fuel (1) is crushed in a mill (2) and fed to a filter/separator (3) by means of a propellant and drying gas, and at least part of the propellant/drying gas in the circuit is returned to the mill (2) after heating, the known disadvantages are not only to be avoided, but particularly a cost-effective milling and drying method and a corresponding system are to be provided, having low emissions and a low inert gas requirement. This is achieved according to the method in that part of the propellant/drying gas flow in cooled down and dehumidified in a spray tower (6), or the like, wherein part of the dried gas exiting the spray tower is fed to the environment and/or a firing process, and the other part is returned to the propellant/drying gas flow.
Abstract:
An apparatus and method for fuel preparation for example by milling and drying to produce a pulverous fuel supply are described. The apparatus includes a fuel preparation unit adapted to receive a mixture of fuel and a gas and to prepare the fuel for combustion in a pulverous state; an output conduit defining an output flow path for a mixture of pulverous fuel and gas from the fuel preparation unit; a phase separator disposed to receive the mixture from the output conduit and to separate the mixture into a gas phase comprising at least a major part of the gas from the mixture and a fuel phase comprising the pulverous fuel; a gas phase conduit defining a flow path for the gas phase from the separator; a heat exchanger preferably being a process fluid heat exchanger such as a feed water heat recovery heat exchanger fluidly connected to the gas phase conduit and adapted to receive and dry the gas phase. The method applies the principles embodied in the apparatus.
Abstract:
Using oxygen-lean gas as the transport medium in which pulverized fuel solids are conveyed to the burner of a combustion system permits combustion at levels of combustion rate and NOx production under circumstances under which those levels would not be attainable if the transport medium were air.
Abstract:
An apparatus and method for fuel preparation for example by milling and drying to produce a pulverous fuel supply are described. The apparatus includes a fuel preparation unit adapted to receive a mixture of fuel and a gas and to prepare the fuel for combustion in a pulverous state; an output conduit defining an output flow path for a mixture of pulverous fuel and gas from the fuel preparation unit; a phase separator disposed to receive the mixture from the output conduit and to separate the mixture into a gas phase comprising at least a major part of the gas from the mixture and a fuel phase comprising the pulverous fuel; a gas phase conduit defining a flow path for the gas phase from the separator; a heat exchanger preferably being a process fluid heat exchanger such as a feed water heat recovery heat exchanger fluidly connected to the gas phase conduit and adapted to receive and dry the gas phase. The method applies the principles embodied in the apparatus.
Abstract:
A biomass-mixed-firing pulverized coal fired boiler includes: a furnace for burning biomass fuel together with pulverized coal in a mixed state; a pulverized coal burner for supplying the pulverized coal into the furnace; a biomass burner for supplying the biomass fuel into the furnace; a biomass mill for milling the biomass fuel to be supplied to the biomass burner; a dry clinker processing unit provided below the furnace and including a clinker conveyor for carrying ashes discharged from the furnace at a furnace bottom; and a combustion-air supply unit for supplying combustion air toward the ashes discharged at the furnace bottom on the clinker conveyor, thereby to burn an unburned component of the biomass fuel contained in the ashes discharged at the furnace bottom on the clinker conveyor.