FI60736B - FOERFARANDE FOER BEHANDLING AV MATERIAL I EN VIRVELBAEDDSREAKTOR - Google Patents

Description

60736

Method for treating substances in a fluidized bed reactor Förfarande för behandling av materia! i en virvelbäddsreaktor ✓ 0

The present invention relates to a process according to patent No. 54160 (pat. No. 762695) for treating substances in a fluidized bed reactor, in which the substance to be treated is contacted with solid particles separated from the flue gases of the fluidized bed reactor before being fed to the Lei fluidized bed reactor.

It is an object of the present invention to apply a method 10 for the thermal decomposition of organic matter to produce crude gases containing carbon monoxide and hydrogen as well as hydrocarbons. The heat treatment of the substance is carried out in an oxygen-free state or in the presence of oxygen, depending on the desired gasification result and the substance to be treated.

15 The method can be applied to, for example, peat, coal and other solid fuels, oil sands or shale, and various solid wastes.

The process makes it possible to produce raw gases which can be used as such as fuel gases or which can be processed, for example, into synthesis gases as raw materials for the chemical industry or as reduction gases for metallurgical applications.

In the past, gasification of solids has been carried out, for example, according to the method described in U.S. Patent 3,840,353, in which granulated carbonaceous fuel is fed to a fluidized bed reactor and solid particles separated from flue gases are returned to it. The combustion and gasification of the carbonaceous substance take place in the same reactor, so that it is difficult to control the reactions in the desired manner.

In the method according to the invention, the gasification process and the combustion process are separated from each other, so that the gasification can take place at a lower odor temperature than the actual combustion process. The temperatures of both processes can be easily adjusted independently.

The heat required for gasification is obtained mainly indirectly from the combustion process 5, i.e. from hot dust separated from the flue gases and not, as in previously known methods, directly from the combustion process.

The invention will now be described in more detail with reference to the accompanying drawing, which schematically shows the plant required for applying the method.

The moist substance is fed to the flue gas duct 2 by means of a feed device 1. In the flue gas duct, the substance is preheated and dried before a pin mill 3, which decomposes and dispenses it into the gas stream in the riser 4, where the actual drying takes place. The dried substance is separated from the gas in a separator 5 and the gas is purified in a scrubber 6. The dried substance is fed via line 7 to a pre-reactor 8, to which hot dust separated from the flue gases in the cyclone 9 is also introduced. In the pre-reactor, the dust and the substance to be treated are mixed together to obtain the desired thermal reaction. The resulting gases are removed via line 10 and the carbon residue containing dust separated from the flue gases is fed to the fluidized bed reactor 11 by means of a feed screw 12. By adjusting the amounts entering and leaving the pre-reactor relative to each other, the temperature in the pre-reactor can be adjusted to the desired value in the range of 400 to 1000 ° C. The gases are cleaned in a dust separator 13 and a gas scrubber 14. If necessary, air, steam or other gases can also be fed to the pre-reactor via line 15.

In the fluidized bed reactor 11, the combustible components 30 of the carbon residue are incinerated in a manner known per se under oxidizing conditions. If the heat content of the substance fed to it is not sufficient to maintain the combustion temperature in the range of 600 ... 1000 ° C, fuel is added via line 16. In addition to the ash generated by the substance, it can be used as a heat - containing substance as well

Claims (2)

60736 inert substances and substances promoting the gasification process. Example 16/7 g / s tur 60% dryness was dried to 90% dryness in a fluidized bed reactor flue gas with a temperature of 480 ° C after the air preheater. In the pre-reactor f, the peat was pyrolyzed at a temperature of 800 ° C by circulating 270 g / s of cyclone dust. The purified pyrolysis gas contained CO 40% H 2 47% 10 CH 4 2.5% C H 3.0% n m CO 2 3.0% O 2 0.3% h 2 s 0.1% 15 H 2 O 4.5%. Its calorific value was 14.2 MJ / m, i.e. about 60% of the energy content of peat. Gas production was about 10 dm / s. The carbon residue was burned in a fluidized bed reactor at a temperature of about 900 ° C. A process for treating substances in a fluidized bed reactor according to patent 54160 (Pat. No. 762695), wherein the substance to be treated is contacted with solid particles separated from the flue gases of the fluidized bed reactor before being fed to the fluidized bed reactor, characterized in that the flue gas separated solid particles gasification of the organic components of the substance. Process according to Claim 1, characterized in that the substance is heat-treated by means of solid particles separated from the flue gases in the absence of oxygen and the pyrolysis gases formed are separated off, after which the carbon residue is incinerated in a bed reactor.