The invention is an improved system for solid fuel gasification, such as coal. A coal type fuel is reduced to as near a one hundred percent molecularly dispersed condition as possible to achieve the maximum efficiency of combustion in a combustion type device. The system consists of a series of steps. The first step mechanically pulverizes the coal to pass through a 300 mesh screen. The second step thermally drives off the volatile gases and the char is burned to a carbon monoxide gas state. The resulting gasified coal combination is then fed to the burners of the combustion type device.

A method for desulfurization, denitrification, and oxidation, of carbonaceous fuels including a two stage oxidation technique. The carbonaceous fuel, containing ash, along with an oxygen-containing gas is introduced into a first stage partial oxidation unit containing a molten ash slag maintained at a temperature of about 2200.degree.-2600.degree. F. A flux may also be introduced into the first stage partial oxidation unit for the purpose of increasing the basicity and maintaining the viscosity of the molten ash slag at a value no greater than about 10 poise. The carbonaceous fuel is gasified, and sulfur is chemically bound and captured in the molten ash slag. Since the first stage is operated in a gasification mode (reducing atmosphere), essentially all of the nitrogen in the fuel is converted to diatomic nitrogen, which results in low nitrogen oxide emissions upon final combustion. The first stage is also designed to physically remove a major portion of the fuel ash, the ash leaving the system as a molten slag. The combustible gas derived from partial oxidation (gasification) is directed along a substantially horizontal path to a second stage oxidation unit for final combustion. The sulfur-containing molten slag is removed to a water-sealed quench system or indirect water cooled system for disposal.

A continuous process for the combustion of carbonaceous fuels under conditions such that oxides of nitrogen are not formed and oxides of sulfur and particles of ash are effectively prevented from contaminating the gaseous products released to the atmosphere. Fuel is charged as a slurry in alkaline aqueous solution and contacted with combustion air so that the catalytic properties of both water and alkali operate to permit rapid and complete combustion at unusually low temperatures. Useful heat is extracted from the heated mixture. At the low combustion temperatures, sulfur in the fuel oxidizes to the trioxide which dissolves completely in the alkaline liquid phase which also retains particles of ash and unburned fuel.

A method for desulfurization and oxidation of carbonaceous fuels including a two stage oxidation technique. The carbonaceous fuel, along with an oxygen-containing gas is introduced into a first stage partial oxidation unit containing molten slag maintained at a temperature of about 2200.degree.-2600.degree. F. A flux may also be introduced into the first stage partial oxidation unit for the purpose of maintaining the viscosity of the molten slag at a value no greater than about 10 poise. The carbonaceous fuel is gasified, and sulfur is chemically bound and captured in the molten slag. The combustible gas derived from partial oxidation and gasification is directed along a substantially horizontal path to a second stage oxidation unit for final combustion. The sulfur-containing slag is removed to a water-sealed quench system for disposal.

This invention relates to a plant and arrangement and method for the low temperature carbonization of waste material with low-temperature carbonization device and a secondary incineration chamber. The heating system of the low-temperature carbonization device is substantially corrosion-free and gases hazardous to the environment are transformed into gases with a lower level of hazardous matter in a simple manner by directing the heating gas of the low-temperature carbonization device into a closed loop cycle through a low temperature carbonization device and into a heat exchanger of a secondary incineration device. The heat exchanger is equipped with a lining which insures a temperature of the burner gases in the heat exchanger of 1200.degree. C. or more for a period of dwell of 1 to 5 sec.