JPS5851036B2 - Suiso Oyobi Itsusankatansogan Yuugasuno Seihou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing hydrogen and carbon monoxide containing gases from carbonaceous fuels.

By reacting a well-dispersed carbonaceous fuel with oxygen diluted with nitrogen and/or water vapor in a one-step process,
Methods for producing gases containing hydrogen and carbon monoxide have already been proposed.

High temperatures are required for such processes, resulting in the consumption of large amounts of oxygen, so that the yields of CO and H2 are relatively low.

It has now been found that the yields of CO and H2 can be increased by carrying out the production process in two stages.

Accordingly, the present invention provides a method for producing hydrogen and carbon monoxide-containing gas from carbonaceous fuel, in which diluted oxygen and 50-95% of the carbonaceous fuel are provided in a first reaction zone maintained at a relatively high average temperature. and the remaining portion of the carbonaceous fuel is introduced into the second reaction zone together with the effluent of the first reaction zone, or the remaining portion of the carbonaceous fuel is introduced into the second reaction zone and the remaining portion of the carbonaceous fuel is introduced into the second reaction zone and Either the effluent of one reaction zone is introduced separately into a second reaction zone, or a portion of the remaining portion of the carbonaceous fuel is combined with the effluent of the first reaction zone and introduced into a second reaction zone and the carbonaceous fuel is introduced into the second reaction zone. The method is characterized in that another portion of the residual portion of the fuel is separately introduced into the second reaction zone, and the average temperature of the second reaction zone is substantially lower than the average temperature of the first reaction zone.

Any carbonaceous fuel can be used as a feedstock for the process of the invention.

As used herein, the term 1+carbonaceous fuel 11 refers to any combustible material of which a substantial portion is composed of carbon.

The fuel may contain oxygen, sulfur and/or nitrogen.

Such feedstocks include, for example, lignite, anthracite, slag coal, coking shale oil, mineral oil or petroleum fractions, tar sands oil or natural gas.

If the feedstock is a solid, it should be in powder form so that it can readily react with the oxygen in the first reaction zone.

Desirably, the size of the solid carbonaceous fuel is reduced so that 70% of the fuel has a particle size of less than 200 mesh.

Oxidants include water vapor, carbon dioxide, oxygen and air diluted with nitrogen and/or argon.

It is advisable to preheat the oxidant before reacting it with the carbonaceous fuel.

Preheating of the oxidant is suitably carried out indirectly by means of a heat exchanger using any heat source, for example the hot product gas obtained in the process of the invention.

It is desirable to preheat the oxidant to a temperature in the range of 200 to 1300° C. depending on the type of the oxidant.

After preheating, it is expedient to mix the hot oxidant with the carbonaceous fuel and introduce the oxidant/fuel mixture into the first reaction zone, preferably as a jet.

The amount of fuel to be introduced into the first reaction stage in the process of the invention is between 50 and 95% of the total amount of fuel to be gasified, the remaining part of the fuel being introduced into the first stage effluent or into the second reaction stage. Directly into the reaction zone.

Preferably, the first reaction zone consists of an empty steel vessel lined on the inside with a refractory material.

Partial combustion in the first reaction zone is preferably carried out at a temperature in the range of 1200-1700°C resulting from the reaction of the carbonaceous fuel with the oxidant.

The pressure maintained in the first reaction zone may vary within a wide range and is desirably kept in the range of 1 to 200 kg/cat absolute.

In a preferred embodiment, the mixture of oxidant and carbonaceous fuel is introduced into the first reaction zone at high velocity.

Suitable linear introduction rates range from 10 to 200 rrL/sec.

In order to convert all of the carbonaceous fuel introduced into the first reaction zone into product gas, the solid particles should remain within the zone for a residence time.

It is advisable to select the residence time of the reactants in the range from 0.02 to 20 seconds.

The residence time is preferably 0.5 to 20 seconds.

After at least a substantial portion of the carbonaceous material has been converted to gas, the reaction products, which primarily include N2, CO, N2, CO2 and N20, are removed from the first reaction zone and introduced into the second reaction zone.

In the case of the present invention in which only a portion of the carbonaceous material to be gasified is introduced into the first reaction zone, the remaining portion of the carbonaceous material is preferably introduced into the first reaction zone together with water vapor, nitrogen and/or CO2. effluent and/or introduced into the second reaction zone.

The amount of fuel to be introduced into the effluent of the first reaction zone is approximately 50% of the total amount of fuel to be gasified to hydrogen and carbon monoxide.
It is desirable that it be 50%.

The amount of water vapor, nitrogen and/or CO2 introduced into the effluent of the first reaction zone together with the remainder of the fuel is
A range of TTf to 2 Nm'' per kg is desirable.

It is expedient for the diluent gas to have a pressure in the range from 2 to 210 kg/crrt absolute and a temperature in the range from 100 to 700<0>C.

The mixture of the effluent of the first reaction zone, and optionally also the remaining portion of the fuel, with water vapor, CO2 and/or N2 is then introduced into the second reaction zone where the carbonaceous The material is substantially completely converted to carbon monoxide and hydrogen by the CO2 and/or water vapor.

The conversion is carried out at a temperature at least 100°C lower than the temperature of the first stage, preferably from 600 to 1400°C.

Pressure may be atmospheric pressure or overpressure, 200 absolute kg/c
A pressure of up to a is suitable.

Preferably, the second reaction zone consists of an empty steel vessel lined on the inside with a refractory material.

The capacity of the second reaction zone should be large enough to provide a reactant residence time long enough to substantially completely convert the remaining portion of the fuel to gaseous components.

The residence time is preferably in the range of 0.5 to 40 seconds.

After the conversion is complete, the final gaseous reaction product is removed from the second reaction zone.

The reaction product has a temperature in the range 600-1400°C.

The dry gaseous reaction product has the following composition:

capacity% C.O. 10-70 2 5-50 The method of the invention is further illustrated by the following examples.

The invention is in no way limited by the examples.

Example Coal with the following composition was used as feedstock.

The coal contained 33.8% by weight volatile components and 2.6% by weight water.

The coal was ground into powder, 70% of which could pass through a 200 mesh sieve.

1028 kg of coal is mixed with 858 kg of oxidizing gas containing 98.9% by weight of 02 and steam 91 with a temperature of 300°C.
mixed with kg.

The coal/gas suspension was introduced into the first reaction zone at a linear velocity of 65 m/sec.

The reaction temperature in the first reaction zone was 1500° C. and the pressure was 40 kg/crti absolute.

The residence time of the reactants in the first reaction zone was 4 seconds.

After the coal has been converted, the reaction product is removed from the first reaction zone and contains 116 kg of the aforementioned coal and 50 absolute kg/cr.
Steam 135 with a pressure of ri and a temperature of 300 °C
kg into the second reaction zone.

The reaction product of the first reaction zone was reacted with coal and steam in a second reaction zone.

The reaction conditions were as follows.

Temperature: 1100℃ pressure crab 39 kg/crtt Residence time = 6 seconds After drying the final product, the gas mixture had the following composition:

Claims (1)

[Claims] 1. In a method for producing hydrogen and carbon monoxide-containing gas from carbonaceous fuel, diluted oxygen and carbonaceous fuel
0 to 95% are reacted in a first reaction zone maintained at a relatively high average temperature, and the remaining portion of the carbonaceous fuel is introduced into a second reaction zone together with the effluent of the first reaction zone. Alternatively, the remaining portion of the carbonaceous fuel may be introduced into the second reaction zone and the effluent of the first reaction zone may be separately introduced into the second reaction zone, or a portion of the remaining portion of the carbonaceous fuel may be introduced into the first reaction zone. introducing the remaining portion of the carbonaceous fuel into the second reaction zone together with the effluent of the reaction zone, and introducing another portion of the remaining portion of the carbonaceous fuel separately into the second reaction zone; A method characterized in that the temperature is substantially lower than the average temperature of the reaction zone.