Coal Gasification in Moving Bed Reactor with a Draft Tube

1 INTRODUCTIONMany different types of reactors,for example,fixed bed,moving bed,fluidized bed and spoutedbed,have been used in industrial production and laboratory in research studies.Althougheach of these coal gasifiers has its own specific advantages,there exists,generally speaking,certainwaste gas in product gas because of the direct burning of coal with oxygen or air to provide heatneeded in the endothermic process of coal gasification in gasifiers.A new type of moving bed

Coal Gasification in Moving Bed Reactor with a Draft Tube

1 INTRODUCTION Many different types of reactors, for example, fixed bed, moving bed, fluidized bed and spouted bed, have been used in industrial production and laboratory in research studies1-6]. Although each of these coal gasifiers has its own specific advantages, there exists, generally speaking, certain waste gas in product gas because of the direct burning of coal with oxygen or air to provide heat needed in the endothermic process of coal gasification in gasifiers. A new type of moving bed reactor with a draft tube for coal gasification is presented in this paper. This kind of coal gasifier has the following characteristics: (1)The endothermic process of coal gasification in the moving bed is separated from the heat providing process, so that rich hydrogen product gas with high calorific value can be obtained, even when air is used as oxidant; (2)The needed heat in the moving bed for coal gasification is provided with a certain amount of red-hot ceramic particles, which are heated in the draft tube by burning part of the product gas with air and circulated within the draft tube, the cyclone and the moving bed; (3)Ash, unreacted coal and ceramic particles are discharged from the bottom of the moving bed by gravity, and blown upwards by compressed air through the draft tube and then separated in the cyclone; (4)Fine particles of coal are needed to transfer heat more effectively between the coal and the red-hot ceramic particles in the moving bed.