AU2015268773A1

AU2015268773A1 - A brown coal gasification system and method thereof

Info

Publication number: AU2015268773A1
Application number: AU2015268773A
Authority: AU
Inventors: Mo CHU; Xiongchao LIN; Jialiang SUN; Yonggang Wang; Lubin WEI; Deping Xu; Haiyong ZHANG
Original assignee: China University of Mining and Technology Beijing CUMTB
Current assignee: China University of Mining and Technology Beijing CUMTB
Priority date: 2015-05-19
Filing date: 2015-12-16
Publication date: 2016-12-08
Anticipated expiration: 2035-12-16
Also published as: CN104910969A; CN104910969B; AU2015268773B2

Abstract

The invention discloses a new type of brown coal gasification system and a method thereof, including gasifier, separator, catalytic reformer and condenser etc. The gasifier is divided into three regions (i.e. upper area, central area and bottom area) from top to bottom. The hole shrinkage is located between upper area and central area. The internal cylinder with an opening at the bottom is installed in the upper part where secondary drying of pulverized coal is occurred. The central area is gasification zone; the slag storage device is at the bottom of gasifier. The slag drip opening is installed in the bottom of slag storage device. The nozzle is installed at the top of gasifier which connected with screw feeder and dry separation device with air medium. The high temperature gas entrance, gas outlet and gasifying agent inlet are set in side wall of gasifier. The gas outlet connects with separator, catalytic reformer and condenser in sequence. The invention integrates dry separation, dehydration and gasification which has advantages of water saving, energy conservation, high gasification efficiency and high quality product gas etc. It is gasified for brown coal and carbonaceous materials in mild conditions to produce gas, water gas and syngas with high efficiency. rushing BrowniIF_ Secondary Mild Catalyic -pDry seperation rCO coal drying gasificati n reforming De-hydration Coal gas de-ashing Fig. 1. N2 serew feeder H20 2 catalysts------- raw gas 1 3 1 4 recirculated water - -wga condenser s eperat i carbon de etive coal gas particles catalysts--------1 _ _ v 1 gasifier Fig. 2.

Description

2015268773 16 Dec 2015 P/00/011 Regulation 3.2 Australia

Patents Act 1990

COMPLETE SPECIFICATION STANDARD PATENT

Invention Title: A brown coal gasification system and method thereof

The following statement is a full description of this invention, including the best method of performing it known to us: 1001308340 2015268773 16 Dec 2015 A brown coal gasification system and method thereof

FIELD OF THE INVENTION 5 The invention relates to a type of brown coal gasification technology, particularly to a new type of brown coal gasification system and method thereof.

BACKGROUND OF THE INVENTION 0 The energy is the foundation of social and economic development; the demand for the energy is more and more with the development of society. The utilization and development of the energy restricts the development of economic society and influences the natural environment. China’s economy is in the key stage of transformation from high-speed development to steady growth and in the stage of industrialization, urbanization development, so the demand for the 5 energy is more urgent. At present, coal accounts for 75% of total quantity of primary energy production and 70% of total energy consumption. The production and consumption pattern determines that in the recent several decades the dominant position of coal will not be changed and at the same time the environmental problems caused by the production and consumption of coal are increasingly prominent. The clean utilization and development of low-rank coal is more :o urgent with the gradually decrease of high-rank coal resource. The proven reserves resources of brown coal are 129.13 billion ton, which accounts for 12.69% of proven reserves resources of coal. The development of comprehensive efficiency utilization routes and methods for brown coal will ease the tense situation for energy demand in china.

Brown coal is the coal of the lowest degree of coalification with high moisture, high 25 volatiles, low heat value, high ash, and easy to fracture and so on. Therefore, the utilization range and load distance of brown coal are greatly limited and which are difficult for its clean utilization effectively. However, brown coal with low metamorphic property and high reactivity is good raw material for gasification. Coal gasification technology is the main route of coal conversion and the synthesis gas can be used for power generation, synthetic liquid fuel and various chemicals. 30 The pyrolyzation and gasification characteristics of brown coal with high oxygen content, abundant alkali and alkaline earth metals and high volatiles are different from high-rank coal. During the gasification of low rank coal (e.g. brown coal), the volatiles with high activity which is not discharged in time are interacted with char. The interaction results in volatilization of 2 1001308340 2015268773 16 Dec 2015 alkali and alkaline earth metals, changing of char structure (particularly promoting the condensation reaction of aromatic rings) and distribution of catalyst, ultimately changing the reactivity of char.

When the low-rank coal such as brown coal is gasified by existing gasification techniques 5 (i.e. fixed bed gasification, fluidized bed gasification and entrained-flow bed gasification), they are negatively influenced by the interaction between char and volatiles to some degree.

Reference to any prior art in the specification is not an acknowledgment or suggestion that this prior art forms part of the common general knowledge in any jurisdiction or that this prior art could reasonably be expected to be understood, regarded as relevant, and/or combined with other 0 pieces of prior art by a skilled person in the art.

As used herein, except where the context requires otherwise the term ‘comprise’ and variations of the term, such as ‘comprising’, ‘comprises’ and ‘comprised’, are not intended to exclude other additives, components, integers or steps.

5 SUMMARY OF THE INVENTION

Embodiments of the present invention provide a new type of brown coal gasification system and method thereof with water saving, energy conservation, high gasification efficiency and high quality product gas. :0 In a first aspect there is provided a brown coal gasification system, comprising: a gasifier; a separator; a catalytic reformer; and a condenser; 25 wherein, the gasifier is divided into an upper region, a middle region and a lower region from top to bottom; a hole shrinkage is configured between the upper region and the middle region; a internal cylinder with an opening at its bottom is configured in the upper region, the space within the internal cylinder is a secondary drying zone, the middle region is a gasification zone and the lower region is a slag storage; a slag discharge exit is configured at the bottom of 30 the slag storage; wherein, a nozzle is configured at the top of the gasifier; the lower end of the nozzle extends into the internal cylinder and the upper end of the nozzle is connected with a screw feeder; high temperature gas entrance(s) is/ are configured in the side wall of the upper region; 3 1001308340 2015268773 16 Dec 2015 the upper part of the middle region is straight tubular and the lower part of the middle region is cone-shape, gas outlets are configured in the side wall of the straight tubular part and gasifying agent entrances are configured in the side wall of the cone-shape part; the gas outlets are connected with the separator; a gas outlet at the top of the separator is 5 connected with the high temperature gas entrance(s) and an inlet of the catalytic reformer respectively; an outlet of the catalytic reformer is connected with the condenser; an outlet for carbon-containing particles is configured in the bottom of the separator; an inlet for catalysts and an outlet for deactivated catalysts are configured in the top and bottom of the catalytic reformer, respectively; a syngas outlet, an inlet and an outlet of circulating water are 0 configured in the condenser respectively.

In a second aspect there is provided a brown coal gasification method using a brown coal gasification system, comprising the following steps in sequence with brown coal as raw materials: removing ash content and exterior water of pulverized coal by air as medium and then 5 feeding into the secondary drying zone of the gasifier by employing a screw feeder; drying the pulverized coal for a second time and meanwhile contacting the pulverized coal with a gasifying agent to have a gasification reaction in the secondary drying zone and then allowing the volatiles and the chars generated from the gasification reaction to flow into the gasification zone with the heat for the reaction and the secondary drying being from high :0 temperature coal gas outside the internal cylinder; separating and completely gasifying the chars in the gasification zone and allowing the ash residue to enter the slag storage and to be discharged through the slag discharge exit; allowing the raw gas and the volatiles produced in the gasification zone to enter the separator and separating the carbon-containing particles from the raw gas, then allowing a part of 25 the separated raw gas to enter the gasifier to supply the heat for the secondary drying and the gasification reaction and allowing the separated carbon-containing particles to recycling into the gasifier for gasification; allowing the other part of the separated raw coal gas to enter the catalytic reformer to be purified and then to enter the condenser to be cooled and obtaining dry clean gas for a subsequent 30 process.

The technical solutions of the above mentioned invention show that the brown coal gasification system and method integrate dry separation, secondary drying and gasification; specifically, the dry separation is conducted by using air, the secondary drying is heated by high- 4 1001308340 2015268773 16 Dec 2015 temperature coal gas, and the gasification is carried out under atmospheric pressure and low temperature (most preferably no higher than 1373k). Therefore, this invention has advantages of water saving, energy conservation, high gasification efficiency and high quality product gas etc. The invention provides a type of mild gasification technique for brown coal and carbonaceous 5 materials with high reactivity (such as biomass) to gasify to produce coal gas, water gas and syngas.

BRIEF DESCRIPTION OF THE DRAWINGS 0

Fig.l is a process flow diagram of the brown coal gasification method in accordance with an embodiment of the present invention.

Fig.2 is a structure diagram of the f brown coal gasification system in accordance with an embodiment of the present invention. 5 In the Figure 2: 1—a screw feeder; 2—a nozzle; 3—high temperature gas entrance(s); 4—a inner cylinder; 5—a secondary drying zone; 6—gas outlets; 7—a gasification zone; 8—gasifying agent entrances; 9—a slag storage; 10—a slag discharge exit; 11—a separator; 12—a catalytic reformer; 13—a condenser.

:0 DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

The following embodiments will further illustrate the present invention,

Some preferred embodiments of the brown coal gasification system of the invention are as follows: 25 The system comprising: a gasifier; a separator; a catalytic reformer; and a condenser; 30 wherein, the gasifier is divided into an upper region, a middle region and a lower region from top to bottom; a hole shrinkage is configured between the upper region and the middle region; a internal cylinder with an opening at its bottom is configured in the upper region, the space within the internal cylinder is a secondary drying zone, the middle region is a gasification 5 1001308340 2015268773 16 Dec 2015 zone and the lower region is a slag storage; a slag discharge exit is configured at the bottom of the slag storage; wherein, a nozzle is configured at the top of the gasifier; the lower end of the nozzle extends into the internal cylinder and the upper end of the nozzle is connected with a screw feeder and a 5 dry separation device with air as medium; high temperature gas entrance(s) is/ are configured in the side wall of the upper region; the upper part of the middle region is straight tubular and the lower part of the middle region is cone-shape, gas outlets are configured in the side wall of the straight tubular part and gasifying agent entrances are configured in the side wall of the cone-shape part; 0 The gas outlets are connected with the separator; a gas outlet at the top of the separator is connected with the high temperature gas entrance(s) and an inlet of the catalytic reformer respectively; an outlet of the catalytic reformer is connected with the condenser; an exit for carbon-containing particles is configured in the bottom of the separator, an inlet for catalysts and an exit for deactivated catalysts are configured in the top and bottom of the 5 catalytic reformer respectively; a coal gas outlet, an inlet and an outlet of circulating water are configured in the condenser respectively.

The furnace body of the gasifier is constructed by firebrick and the outer wall of the gasifier is made of stainless steel.

The catalytic reformer consists of one or more tar catalytic reforming equipments installed :o in series.

Some preferred embodiments of the brown coal gasification method using the system of the invention are as follows:

The method comprising the following steps in sequence with brown coal as raw materials: removing ash content and exterior water of pulverized coal by air as medium and then 25 feeding into the secondary drying zone of the gasifier by employing a screw feeder; drying the pulverized coal for a second time and meanwhile contacting the pulverized coal with a gasifying agent to have a gasification reaction in the secondary drying zone and then allowing the volatiles and the chars generated from the gasification reaction to flow into the gasification zone with the heat for the reaction and the secondary drying being from high 30 temperature coal gas outside the internal cylinder; separating and completely gasifying the chars in the gasification zone and allowing the ash residue to enter the slag storage and to be discharged through the slag discharge exit; 6 1001308340 2015268773 16 Dec 2015 allowing the raw gas and the volatiles produced in the gasification zone to enter the separator and separating the carbon-containing particles from the raw gas, then allowing a part of the separated raw gas to enter the gasifier to supply the heat for the secondary drying and the gasification reaction and allowing the separated carbon-containing particles to recycling into the 5 gasifier for gasification; allowing the other part of the separated raw coal gas to enter the catalytic reformer to be purified and then to enter the condenser to be cooled and obtaining dry clean gas for a subsequent process.

It is autothermal gasification using H2O, O2 and mixture thereof as the gasifying agent and 0 the temperature of the reaction is maintained by adjusting the ratio of oxygen to steam during the process of the gasification.

The operating temperature of gasifier is between 800°C and 1100°C.

Catalysts used in the catalytic reformer are obtained by pyrolyzing brown coal or brown coal loaded metals and activating thereof with steam. 5 The coal gas, water gas and synthesis gas produced by the method can be used for producing methanol, synthesis ammonia and hydrogen, and also can be used in the fields of IGCC power generation and chemical poly generation. A gasification system (“DDT’ gasification technology for short) being fit for brown coal with the properties of high ash, high moisture high activity and easy fragmentation and the like is :0 developed by integrating de-mineralization, de-watering and gasification. The present invention employs H2O and O2 as gasifying agent and adopts the combination of drying and gasification with entrained-flow bed, thus coal gas quality and char conversion efficiency are effectively enhanced.

Also, the technical solutions of the present invention can effectively gasify brown coal with 25 high conversion ratio.

The brown coal gasification system and method of the invention which is composed of dry separation, secondary drying, mild gasification and catalytic reforming etc. First, the raw brown coal is crushed and then is delivered to be de-mineralized and dried to obtain a pulverized coal in dry separation device in air atmosphere. The pulverized coal is feed into a gasifier via a screw 30 feeder. The pulverized coal and a gasifying agent (i.e. H20, 02, N2 and CO2) are fed into the gasifier through a nozzle with cocurrent flow, and they are dried for a second time and partially gasified in an internal cylinder configured in the upper region of the gasifier. Thus the volatiles and the chars are obtained in the internal cylinder with the required heat being from high 7 1001308340 2015268773 16 Dec 2015 temperature coal gas outside. The gasifier is divided into three regions, the secondary drying and the partial gasification are mainly occurred in the upper region, the chars are separated from the volatiles and then the chars are completely gasified in the middle region, and a slag storage and a slag discharge exit are installed in the lower region. The chars and the volatiles obtained in the 5 upper region enter the middle region where the chars are separated from the volatiles and the chars are completely gasified with a secondary gasifying agent (i.e.H20/02) newly introduced to obtain a raw gas. The raw gas and the volatiles are discharged through gas outlets and enter a separator where carbon-containing particles of the raw gas are removed. One part of the gas after removing carbon-containing particles enters the top of the gasifier to supply the heat for the 0 secondary drying; the other part is condensed to get high-quality syngas after catalytic conversion of a small number of tars therein in a catalytic reformer. The removed carbon-containing particles are recycled into the gasifier for gasification. In the middle region of the gasifier, ashes from complete gasification of the chars enter into the slag storage and are discharged through the slag discharge exit. The chars obtained after activating brown coal or brown coal loaded metals 5 are used as catalysts in the catalytic reformer, which have characteristics of low cost and environment friendliness. The present invention integrates dry separation, secondary drying and gasification together; specifically, the dry separation is conducted by using air, the secondary drying is heated by high-temperature coal gas, and the gasification is carried out under atmospheric pressure and low temperature( no higher than 1373k). Therefore, this invention has :0 advantages of water saving, energy conservation, high gasification efficiency and high quality product gas etc. Specifically:

The brown coal gasification system and method (including dry separation, secondary drying, mild gasification and syngas catalytic reforming) provide a new technical route for efficient clean utilization of low rank coal. This can produce high grade syngas under relatively mild conditions 25 using brown coal as raw material which is rich reserves, but high ash and high moisture, high reactivity and abundant alkali and alkaline earth metals.

Preferably, in the dry separation unit of the system, brown coal is separated under air conditions after being crushed to remove ash and exterior water to prepare coal samples.

In the dry separation unit, the separating medium employs air instead of water, to save water 30 and get high separation efficiency.

Preferably, in the secondary drying unit of the system, brown coal with a gasifying agent enters the gasifier continuously via a screw feeder. The secondary drying and partial gasification 8 1001308340 2015268773 16 Dec 2015 are occurred in the internal cylinder and the heat comes from the high temperature coal gas produced by the gasifier.

In the secondary drying unit, the internal cylinder installed in the gasifier is made from materials with good thermal conductivity. The pulverized coal and the gasifying agent flow 5 downward with cocurrent flow and the high temperature coal gas is outside of the internal cylinder.

Preferably, in the gasifier unit of the system, the furnace body of the gasifier is constructed by firebrick and the outer wall of the gasifier is made of stainless steel. The gasifier is divided into three regions, the secondary drying and the partial gasification are mainly occurred in the 0 upper region, the chars are separated and completely gasified in the middle region, and the slag storage and the slag discharge exit are configured in the lower region.

In the gasifier, the secondary drying and partial gasification of the pulverized coal with the gasifying agent are occurred in the internal cylinder where the chars and volatiles are produced. The chars and the volatiles are separated in the middle region to reduce the inhibition to activity 5 of the chars which is from the interaction of the chars with the volatiles. The chars are gasified with the gasifying agent newly introduced through gasifying agent entrances.

In the middle region of the gasifier, the raw gas from gasification reaction of the separated chars with the gasifying agent newly introduced (H20, 02 and mixture thereof) are discharged from gas outlets together with the volatiles. :o Preferably, in the gasifier unit of the system, it’s autothermal gasification which maintains the temperature of the reaction by adjusting the ratio of oxygen to H20.

The lifetime of the furnace body is increased due to the operating temperature of the gasifier being lower than 1373K.

Preferably, the gasifier unit of this system includes the separator. The raw gas from the 25 gasifier enters the separator where the carbon-containing particles included in the raw gas are removed, then a part of the raw gas is recycled into the gasifier to supply heat for the secondary drying and the carbon-containing particles are recycled into the gasifier for gasification.

In the above mentioned gasifier unit, the raw gas supplies the heat for the secondary drying to improve energy efficiency and gasification efficiency. 30 In the above mentioned gasifier unit, the separated carbon-containing particles are recycled to the gasifier for further gasification, reducing subsequent burden of dust removal and widening particle size range of the feeding coals.

Preferably, in the syngas catalytic reforming unit, the catalysts used are obtained by 9 1001308340 2015268773 16 Dec 2015 pyrolyzing brown coal or brown coal loaded metals and activating thereof with steam. The raw materials of the catalysts are easy to get, and the preparation methods of the catalysts are simple. The deactivated catalysts are easy to dispose, too.

In the catalytic reformer, tar is converted into effective synthetic gas and at the same time 5 some small solid particles are removed after the catalytic reforming.

In the above mentioned catalytic reformer, the fresh catalysts enter from the top of the reactor and the deactivated catalysts are discharged from the bottom of the reactor. It can be continuously operated to improve overall efficiency.

In the above mentioned syngas catalytic reforming unit, one or more tar catalytic reforming 0 equipments are installed in series as required.

Preferably, in the syngas catalytic reforming unit of the system, the raw coal gas including a small amount of tar is catalytically reformed and cooled in the condenser to obtain dry clean gas for a subsequent process.

Preferably, the brown coal gasification system and method of the present invention can be 5 used for producing gas, water gas, synthesis gas, methanol and synthesis ammonia, and also can be used in the fields of IGCC power generation, hydrogen production, chemical poly generation, etc. The resource allocation is reasonable.

Preferably, the brown coal gasification system of the present invention can be used in gasification for brown coal, biomass and other high-activity carbon-containing materials. :o The innovation and beneficial effects of the invention employing the above gasification system and method are as follows: 1. This brown coal gasification system and method which adopt dry separation, secondary drying and mild gasification are water saving, cost saving, high energy efficiency and high benefit. 25 2. In this brown coal gasification system and method of the present invention, the chars and volatiles are separated in the middle region of the gasifier, reducing the adverse impact between the volatile and the chars. The chars are completely gasified with the secondary gasifying agent in the bottom of the gasifier. A part of high-temperature coal gas enters the gasifier to supply the heat for the secondary drying, and the carbon-containing particles from the separator are recycled 30 to the gasifier for gasification. This enhances gasification efficiency and widens particle size of pulverized coal. 3. In this brown coal gasification system and method of the present invention, catalytic reforming of a small amount of tar in the gas increases gas quality and yield. 10 1001308340 2015268773 16 Dec 2015 4. In this brown coal gasification system and method of the present invention, the chars from pyrolysis or gasification of brown coal are used as catalysts for catalytic reforming of tar. The cost of the catalysts is low and resources are fully utilized.

5 A SPECIFIC EMBODIMENT

As shown in Fig.l and Fig.2, brown coal after being crushed are delivered into dry separate device to de-ash and dehydrate to obtain the coal samples. The coal samples are grinded and sieved to get the pulverized coal with the particle size between 60mesh and 200mesh. The 0 pulverized coal with inert gas and reaction gas are fed into the nozzle 2 of the gasifier through the screw feeder. The temperature in the gasifier is increased to the desired temperature (i.e. 800 to 1100°C) before feeding the materials. The pulverized coal and the reaction gas are dried and carry out a redox reaction in the secondary drying zone 5, to produce the gases of CO, H2 and CH4 etc, a small amount of tar and chars. The gases and the chars are separated in the middle of 5 the gasifier; The gases containing a small amount of tar are discharged from the gas outlet 6; the chars are completely gasified with H20/02 from the gasifying agent entrances 8, the resultant coal gas is discharged from the gas outlet 6 too, and the resultant ash residues drop into the slag storage 9 and are discharged from the slag discharge exit 10 for subsequent analysis. The coal gas enters the separation 10 and a small amount of solid particles contained in the coal gas are :0 removed, then a part of coal gas enters the gasifier via the high temperature gas entrance(s) 3 to supply the heat for the secondary drying, the other part enters into the catalytic reformer 12. The small amount of tar is converted into effective gas under the catalytic action of alkali metal and alkaline earth metal, thus gas quality is improved. The separated carbon-containing particles are recycled to the gasifier for gasification. The coal gas from the catalytic reformer 12 goes into the 25 condenser 12 in which the temperature of the gas is reduced to less than 100°C for the next process. The gas samples are obtained from sample tap and its gas composition is analyzed.

The person skilled in the art may understand that, based on the teachings of the present description, some modifications or amendments can be conducted to the present invention. These modifications and amendments should also be within the scope defined by the claims of the 30 present invention. 11

Claims

1. A brown coal gasification system comprising: a gasifier; a separator; a catalytic reformer; and a condenser; wherein, the gasifier is divided into an upper region, a middle region and a lower region from top to bottom; a hole shrinkage is configured between the upper region and the middle region; an internal cylinder with an opening at its bottom is configured in the upper region, the space within the internal cylinder is a secondary drying zone, the middle region is a gasification zone and the lower region is a slag storage; a slag discharge exit is configured at the bottom of the slag storage; a nozzle is configured at the top of the gasifier; the lower end of the nozzle extends into the internal cylinder and the upper end of the nozzle is connected with a screw feeder and a dry separation device with air medium; high temperature gas entrance(s) is/ are configured in the side wall of the upper region; the upper part of the middle region is straight tubular and the lower part of the middle region is cone-shape; gas outlets are configured in the side wall of the straight tubular part and gasifying agent entrances are configured in the side wall of the cone-shape part; the gas outlets are connected with the separator; a gas outlet at the top of the separator is connected with the high temperature gas entrance(s) and an inlet of the catalytic reformer, respectively; an outlet of the catalytic reformer is connected with the condenser; an exit for carbon-containing particles is configured in the bottom of the separator; an inlet for catalysts and an exit for deactivated catalysts are configured in the top and bottom of the catalytic reformer respectively; a syngas outlet, an inlet and an outlet of circulating water are configured in the condenser respectively.

2. A brown coal gasification system according to claim 1, wherein the furnace body of the gasifier is constructed by firebrick and the outer wall of the gasifier is made of stainless steel.

3. A brown coal gasification system according to claim 1, wherein the catalytic reformer consists of one or more tar catalytic reforming equipments installed in series.

4. A brown coal gasification method comprising the following steps in sequence with brown coal as raw materials: removing ash content and exterior water of pulverized coal by air as medium and then feeding into the secondary drying zone of the gasifier by employing a screw feeder; drying the pulverized coal for a second time and meanwhile contacting the pulverized coal with a gasifying agent to have a gasification reaction in the secondary drying zone and then allowing the volatiles and the chars generated from the gasification reaction to flow into the gasification zone with the heat for the reaction and the secondary drying being from high temperature coal gas outside the internal cylinder; separating and completely gasifying the chars in the gasification zone and allowing the ash residues to enter the slag storage and to be discharged through the slag discharge exit; allowing the raw gas and the volatiles produced in the gasification zone to enter the separator and separating the carbon-containing particles from the raw gas, then allowing a part of the separated raw gas to enter the gasifier to supply the heat for the secondary drying and the gasification reaction and allowing the separated carbon-containing particles to recycling into the gasifier for gasification; allowing the other part of the separated raw coal gas to enter the catalytic reformer to be purified and then to enter the condenser to be cooled and obtaining dry clean gas for a subsequent process.

5. A method of brown coal gasification according to claim 4, wherein it is autothermal gasification using H20, 02 and mixture thereof as the gasifying agent and the temperature of the reaction is maintained by adjusting the ratio of oxygen to steam during the process of the gasification.

6. A method of brown coal gasification according to claim 5, wherein an operating temperature of the gasifier is between 800°C and 1100°C.

7. A method of brown coal gasification according to claim 6, wherein catalysts used in the catalytic reformer are obtained by pyrolyzing brown coal or brown coal loaded metals and activating thereof with steam.

8. A method of brown coal gasification according to claim 7, wherein the coal gas, water gas and synthesis gas produced by the method can be used for producing methanol, synthesis ammonia and hydrogen, and also can be used in the fields of IGCC power generation and chemical poly generation.

9. A method as claimed in any one of claims 4 to 8 which is performed using a brown coal gasification system as claimed in any one of claims 1 to 3.