WO2012068931A1

WO2012068931A1 - A system for producing solid, liquid and gas products from coal and bio-substance mass, and a method for producing solid, liquid and gas products by using the same

Info

Publication number: WO2012068931A1
Application number: PCT/CN2011/080854
Authority: WO
Inventors: Ke Liu; Carlos A. Cabrera; Qiang QIN
Original assignee: National Institute Of Clean-And-Low-Carbon Energy
Priority date: 2010-11-24
Filing date: 2011-10-17
Publication date: 2012-05-31
Also published as: CN102021035A; CN102021035B

Abstract

The present application relates to a system for producing solid, liquid and gas products from coal and bio-substance mass, and also a method for producing solid, liquid and gas products by using the same, wherein its operation just relies upon entire circulation, between pyrolyzer and gasifier, of heat generated in the above system and realization of calorific balance without feeding of any external resource of heat into the above system, therefore the heat efficiency of this system in greatly enhanced, and the costly radiant syngas cooler (RSC) could be deleted from the system, wherein the quench unit and spraying quench media into area nearby outlet of the syngas stream inside of the gasifier for quenching syngas stream allow that syngas from the gasifier is fed into the pyrolyzer, that thus guarantees controlling operation temperature of the pyrolyzer into range desired by pyrolysis reaction without external heat source for the pyrolysis reaction.

Description

A system for producing solid, liquid and gas products from coal and bio-substance mass, and a method for producing solid, liquid and gas products by using the same

Technical field

The present application relates to a system for producing solid, liquid and gas products from coal and bio-substance mass, and also a method for producing solid, liquid and gas products by using the same, more particularly, to a system for producing solid, liquid and gas products from coal and bio-substance mass, and also a method for producing solid, liquid and gas products by using the same, wherein its operation just relies upon entire circulation, between pyrolyzer and gasifier, of heat generated in the above system and realization of calorific balance without feeding of any external resource of heat into the above system.

Background art

Coal and bio-substance mass pyrolysis needs energy supply to remove the water and extract the volatiles to get the pyrolysis products. The Encoal process supplies the energy via the hot flue gas generated. The Lurgi process provides the heat by way of combustion of certain amount of coal via oxygen injection at bottom of the gasifier.

US Patent 4578175, for example, disclosed that finely divided coal was reacted in a combination of processes comprising flash pyrolysis and fluidized bed gasification of char from the pyrolysis, wherein a portion of the hot char inventory from gasifier was continually added to pyrolyzer by way of a line to provide pyrolysis heat. Depending upon heat loss, line sizes, etc. of the specific equipment, the weight ratio of solids fed to pyrolyzer as expressed by char rate in said line to coal rate, could vary between about 1.5:1 and about 4:1.

By way of example, US Patent 5401364 provided a process for the heat treatment of non-caking, non-coking coal with a process derived gaseous fuel having a variably controllable calorific heating value, wherein the process derived gaseous fuel exiting from the separation system was mixed with the auxiliary fuel and air and combusted in the first combustor to produce products of combustion having the desired chemical substance, and then the products of combustion were mixed with process derived gaseous fuel to attemper the products of combustion to achieve the desired outlet temperature and mass flow rate for subsequent introduction into the pyrolyzer.

US4704135 disclosed an apparatus for converting coal to gas, liquid and solid products, wherein the coal was subjected to a pyrolysis reaction at a temperature of at least about 260 ^°C in the presence of a hydrogen-containing gas; and the resultant solid residue was subjected to a gasification reaction with oxygen and steam at a temperature of at least about 482 ^°C, thereby generating the necessary hydrogen -containing gas for the pyrolysis reaction and producing a solid product. Heat generated in the gasification reaction was transfer to the pyrolysis reaction, so the apparatus did not require any external source of heat except for means to control the temperature of gases passing to the pyrolysis reaction chamber. The gaseous fraction generated in the pyrolysis reaction was cooled to produced liquid and gas products, preferably after having first been subjected to a Fischer-Tropsch reaction.

Above prior art has following shortcomings: although pyrolysis heat could partially or entirely from heat generated in the gasification reaction, entire heat circulation, between pyrolyzer and gasifier, of heat generated in the system could not be realized because just part of final products generated in gasification reaction was circulated to pyrolyzer, and the heat carried by the above part for pyrolysis reaction was part, was not entirety of gasification heat; since just part of final products generated in gasification reaction was circulated to pyrolyzer, there was still needed a cooler for high temperature gasified product to cool residue of the above final products, therefore the highly expensive gasified products cooler could not be deleted, and cost and complexity of operation and maintenance of the above system would be very high; especially, for example, the apparatus disclosed in US4704135 integrated pyrolyzer with gasifier, it operated only under common pressure or low pressure, and low temperature, instead of high pressure and high temperature for industrialized processes, furthermore, the gasification temperature of about 482 "C strictly is not real gasification temperature for industrial processes because only weak and minor gasification reaction takes place at such temperature, thereby heat generated in such gasification reaction is very limited.

In gasification, the syngas coming out of the gasifier could be as high as 1100-1600 degrees Celsius. In order to cool products from gasification reaction, and recover the energy carried by high temperature syngas, one has to build a very expensive Radiant Syngas Cooler (RSC). Imagine that a RSC for a 3000 ton/day gasifier is taller than the Statue of Liberty. In fact, the RSC is typically a few times more expensive than the gasifier itself. The reason is obvious since RSC requires exotic specific materials to sustain a high temperature of over about 1400 degrees Celsius and a pressure of up to 60 bars in a reduced environment with H₂, CO, H₂S, steam C0₂ etc. In addition, the fouling of RSC can reduce the heat transfer efficiency a lot.

Another method for cooling syngas used in industrial current practice is entire quench where high temperature syngas is rapidly cooled to saturated temperature directly by a large amount of water, which is generally about 300-400 ^°C depending to operation pressure. In this cooling method, the fact that the high temperature gas is directly cooled into low temperature causes a lot calorific energy loss during cooling so as to greatly decrease energy efficiency in the entire system, in spite of its building cost being lower than Radiant Syngas Cooler (RSC).

US5713312, US7587995 and US2003/0089038 disclosed several types of syngas cooler with various structures and different operation conditions; US7730616 disclosed a method of cooling syngas in a gasifier, however the above cooler and method for cooling syngas still have the above defects including high cost of operation and maintenance, their mechanical structure complexity. The above identified documents are incorporated hereby in entirety by reference.

As so far, there has not been an industrial system or method for producing solid, liquid and gas products from coal, with its operation just upon entire circulation, between pyrolyzer and gasifier, of heat generated in the above system and realization of calorific balance without feeding of heat of any external heat resource into the above system.

Summary of the invention

With respect of above defects existing in prior art, the present inventors aim at omitting the much more expensive Radiant Syngas Cooler from the current system or process for converting coal and bio-substance mass to solid, liquid and gas products, while ensuring the pyrolysis heat being entirely supplied by gasification heat and achieving entire circulation, between pyrolyzer and gasifier, of heat generated in the system and realizing of calorific balance of system without feeding of heat of any external heat resource into the system. Surprisingly, it is found by the present inventors that via quenching the high-temperature gasification products stream and recycling the resulting temperature-decreased gasification syngas into the pyrolyzer above mentioned object of the invention can be achieved.

The above system or method according to the present invention could delete the very high expensive Radiant Syngas Cooler (RSC), without any adverse effect on its operation and final resultants, thus the thermal efficiency of its operation greatly increases; on the contrast, the cost of its operation and maintenance remarkably drops.

The one object of the present invention is to provide a system for producing solid, liquid and gas products from coal and bio-substance mass, wherein its operation just relies upon entire circulation, between pyrolyzer and gasifier, of heat generated in the system and realization of calorific balance without feeding heat of any external heat resource into the above system.

Another object of the present invention is to provide a process for producing solid, liquid and gas products from coal and bio-substance mass by using the above said system.

In first aspect of the present invention, a system for producing solid, liquid and gas products from coal is provided, which comprises:

i) coal crusher and optional coal dryer;

ii) first lock hopper system

iii) coal pyrolyzer;

iv) second lock hopper system v) coal gasifier ;

vi) tar recovery unit connected to the pyrolyzer;

is characterized in that said system further comprises:

vii) quench unit;

viii) solid - gas separator;

said above components i)-v) and vii)-viii) are communicated in turn by line, ix) line, passing through the quench unit and the solid - gas separator, for communicating the gasifier with the pyrolyzer; and

wherein the line for communicating the gasifier with the pyrolyzer, and the quench unit allow that syngas from the quench unit or gasifier is fed into the pyrolyzer, that thus guarantees controlling operation temperature of the pyrolyzer into range desired by pyrolysis reaction without external heat source for the pyrolysis reaction.

In the above system, preferably, said quench unit could be a partially quenching unit where the temperature of gasification product stream including syngas stream and liquid slag is sufficiently decreased so as for the liquid slag therein to be converted into solid or even lower temperature, and more preferably, could comprise lines and nozzles for additionally adding water and/or for feeding portion of final syngas from the tar recovery unit into said quench unit. Said second lock hopper system could be replaced by a coal slurry tank and pump connected to the tank, preferably, water is added into said coal slurry tank to form coal slurry.

In the above system, said solid - gas separator could be a cyclone, cyclone cascade, membrane and/or a filter, and the system could further comprises a coal deactivation cooler connected to line between the pyrolyzer and the second lock hopper system or the coal slurry tank to cool portion of char from pyrolyzer to produce upgraded coal. Preferably, said tar recovery unit is a condenser, and slag generated in the gasifier is finally discharged into water tank for water quench treatment.

The above system could further comprise a syngas burner for combusting a portion of the final syngas from said tar recovery unit and then feeding combusted product into the pyrolyzer to provide with heat to pyrolysis reaction.

In the above system, said gasifier could comprise oxygen and /or air inlet and optional steam inlet.

In second aspect of the present invention, a system for producing solid, liquid and gas products from coal is provided, which comprises:

i) coal crusher and optional coal dryer;

ii) first lock hopper system

iii) coal pyrolyzer;

iv) slurry tank

v) pump

vi) coal gasifier ; vii) tar recovery unit connected to the pyrolyzer;

is characterized in that said system further comprises:

viii) quench unit;

ix) solid - gas separator;

above said components i)-vi) and viii)-ix) are communicated in turn by line, x) line, passing through the quench unit and solid - gas separator, for communicating the gasifier with the pyrolyzer ; and

wherein the line for communicating the gasifier with the pyrolyzer and the quench unit allow that syngas from the quench unit or the gasifier is fed into the pyrolyzer, that thus guarantees controlling operation temperature of the pyrolyzer into range desired by pyrolysis reaction without external heat source for pyrolysis reaction.

In third aspect of the present invention, a system for producing solid, liquid and gas products from coal is provided, which comprises:

i) coal crusher and optional coal dryer;

ii) first lock hopper system

iii) coal pyrolyzer;

iv) slurry tank

v) pump

vi) gasifier ;

vii) tar recovery unit connected to the pyrolyzer;

is characterized in that said system further comprises:

viii) solid - gas separator;

above said components i)— i) and viii) are communicated in turn by line,

ix) line, passing through the solid-gas separator, for communicating the gasifier with the pyrolyzer ; and

wherein the line for communicating the gasifier with the pyrolyzer and spraying quench media into area nearby outlet of the syngas stream inside of the gasifier for quenching syngas stream allow that syngas from the gasifier is fed into the pyrolyzer, that thus guarantees controlling operation temperature of the pyrolyzer into range desired by pyrolysis reaction without external heat source for the pyrolysis reaction.

In fourth aspect of the present invention, a system for producing solid, liquid and gas products from coal is provided, which comprises:

i) coal crusher and optional coal dryer;

ii) first lock hopper system

iii) coal pyrolyzer;

iv) second lock hopper system

v) coal gasifier ;

vi) tar recovery unit connected to the pyrolyzer;

is characterized in that said system further comprises:

vii) solid - gas separator; said above components i)-v) and vii) are communicated in turn by line,

viii) line, passing through the solid-gas separator, for communicating the gasifier with the pyrolyzer ; and

In the above system according to the first-fourth aspect of the present invention, said pyrolyzer could have operation temperature ranging from about 300-700 ^°C, preferably about 300-600 °C, most preferably about 300-500°C and operation pressure that could not be more than about 95-99 bar, for example about 75-79 bar, preferably not more than about 50 bar, most preferably not more than about 45 bar; meanwhile said gasifier could have operation temperature ranging from 1100-1700 °C, preferably 1200-1600 ^°C , most preferably 1200-1500^°C and operation pressure that could not be more than about 100 bar, for example about 80 bar, preferably not more than about 55 bar, most preferably not more than about 50 bar, and the operation pressure of said pyrolyzer could be generally about 1 - 5 bar(s) lower than that of said gasifier.

In the above system according to the first-fourth aspect of the present invention, the syngas after solid-gas separation could enter into said pyrolyzer under temperature of below about 900 ^°C.

In the above system according to the first-fourth aspect of the present invention, an additional dryer could be arranged between the first lock hopper system and the pyrolyzer so as to dry raw coal fed into the pyrolyzer so that its moisture content is lower than 5%, drying temperature is generally 80-250 °C, preferably 100-250 ^°C, more preferably 120-200 ^°C .

In the above system according to the first-second aspect of the present invention, the quench unit could be deleted, and quench media is sprayed into area nearby outlet of the syngas stream inside of the gasifier to quench the syngas stream, said quench media comprises water, syngas, and/or carbon dioxide.

In fifth aspect of the present invention, a method for producing solid, liquid and gas products from coal is provided, which comprises following the steps in turn:

a) crushing and optional drying the coal to get finely divided and optionally dried coal;

b) the finely divided and optionally dried coal being fed into the first lock hopper system for pressurization of the coal;

c) Pressurized coal being fed into the pyrolyzer and pyrolyzing the coal in the pyrolyzer into pyrolysis gas stream and char;

d) the char generated in the pyrolyzer being fed into the second lock hopper system for further pressurization of the char or into the slurry tank; e) the further pressurized char or char slurry pressurized by the pump being fed in the gasifier and gasifying said further pressurized char or said char slurry in the gasifier into syngas stream and slag;

f) the said syngas stream and the slag being fed into the quench unit from the gasifier or spraying quench media into area nearby outlet of the syngas stream inside of the gasifier for quenching syngas stream to decrease temperature of the said syngas stream into range that is lower than operation temperature of the gasifier but higher than operation temperature of the pyrolyzer;

g) the slag optionally being fed into water tank from the quench unit or the gasifier for water quench treatment ;

h) the syngas being fed into the solid-gas separator from the quench unit or the gasifier for being separated into solid fly ash and pure syngas;

i) the pure syngas being circulated into the pyrolyzer to make the operation temperature of the pyrolyzer keep into rang required by pyrolysis reaction; and j) together with the pyrolysis gas stream, the pure syngas being fed into the tar recovery unit from the pyrolyzer to be separated into final syngas and tar;

wherein the pure syngas is fed into the pyrolyzer, that thus guarantees controlling the operation temperature of the pyrolyzer into the range desired by the pyrolysis reaction without external heat source for pyrolysis reaction.

In the above method, said syngas stream could preferably be partially quenched in the quench unit, and the method could further comprise portion of the char from the pyrolyzer not being fed into the second lock hopper system or the slurry tank, otherwise being cooled for deactivation to get upgraded coal, and oxygen and /or air and optional steam being fed into the gasifier.

In the above method, water and /or a portion of the final syngas from the tar recovery unit could be fed into the quench unit for quenching the syngas stream, and a portion of the final syngas from said tar recovery unit could combust and combusted product then could be fed into the pyrolyzer to provide with heat to pyrolysis reaction.

In the above method, said syngas stream in the gasifier could be not fed into the quench unit while quench media is sprayed into area nearby outlet of the syngas stream inside of the gasifier to quench the syngas stream, the syngas stream from the gasifier could be directly fed into the solid-gas separator, and the quench media could comprise syngas, water and /or carbon dioxide.

In the above method, the syngas stream generated in the gasifier could go upstream or downstream in the gasifier, and particle size distribution of said finely divided and optionally dried coal depends on the gasifier's requirement.

In the above method, a direct coal liquefaction catalyst, for example cheap FeS or FeS₍i-x₎ ( wherein 1-X is about 0.7-0.9), could be added into the pyrolyzer to convert the tar into synthetic oil, and a high temperature sour shift catalyst for water gas reaction could be also added into the pyrolyzer and/or gasifier, especially into bottom of the pyrolyzer.

In the present invention, since only the hot char instead of all the coal is gasified, the oxygen consumption in the gasifier will be much lower, thus the Air Separation Unit used will be smaller, which will in turn cause the cost being greatly reduced. More particularly, through partially quenching the high-temperature gasification product stream and recycling the resultant temperature-decreased syngas into the pyrolyzer, not only the usage of the very expensive Radiant Syngas Cooler is avoided, but also heat exchange will occur between the recycled syngas and the finely divided and optionally dried coal so that at least most or even nearly all of the heat required for pyrolysis reaction is transferred from the recycled syngas to the coal to be pyrolyzed, as a result, the thermal efficiency of the system and method would be greatly enhanced.

Description of the drawings

Figure 1 illustrates first embodiment of the system and method according to the present invention, which uses a downflow dry feed gasifier with the high-temperature gasification product stream being partially quenched by additionally adding water into the quench unit.

Figure 2 illustrates second embodiment of the system and method according to the present invention, which uses a downflow feed gasifier with the high-temperature gasification product stream being partially quenched by additionally adding recycled syngas from the tar recovery unit and optional water into the quench unit.

Figure 3 illustrates third embodiment of the system and method according to the present invention, which uses a downflow dry feed gasifier with the high-temperature syngas stream being quenched by that quench media is sprayed into area nearby outlet of the syngas stream inside of the gasifier, and the syngas stream goes upstream in the gasifier .

Figure 4 illustrates fourth embodiment of the system and method according to the present invention, which is the same as that shown in Fig 2 except for that the second lock hopper system is replaced by the slurry tank and pump connected to the tank.

Figure 5 illustrates fifth embodiment of the system and method according to the present invention, which is the same as that shown in Fig 3 except for that the second lock hopper system is replaced by the slurry tank and pump connected to the tank.

Figure 6 illustrates sixth embodiment of the system and method according to the present invention, which uses a downflow dry feed gasifier with the high-temperature gasification product stream being partially quenched by water in the quench unit, and combustion product of a portion of the syngas from the tar recovery unit within a syngas burner being fed into the pyrolyzer to provide with heat for pyrolysis reaction.

Parts/units or materials fed in/withdrawn out and reference numbers thereof are below table for clarity.

Table 1

Specific mode of carrying out the invention

Within the figures in the accompanying drawings, same reference numbers represent the same or similar part or unit, or the same or similar material to be fed in or withdrawn out.

In consideration of figures 1- 6, it will be understood that for the purpose of clarity the details of some components or apparatuses construction are not provided in view of such details being conventional and well known by a skilled person in the art once the present invention is illustrated below. In addition, many control or monitor devices which are conventional and standard in the field of chemical processing also have been omitted for clarity of illustrating and describing the invention.

Reference may be made to any chemical literatures generally detailedly describing various apparatus and processing conditions. For example, in Figures 1-6, crusher and optional dryer 10, coal pyrolyzer 20, tar recovery unit 23, char deactivation cooler 27 as well as gasifier 30 may be any known commercially available apparatuses or components with the exception that such apparatus components may be modified if necessary by a person skilled in the art to be employed in the present invention as discussed herein.

As used in the present invention, term "partially quenching" or "partially quenched" should be understood to mean that in comparison with completely quenching normally employed in industry practice, only insufficient amount of quenching media such as water is used, so as to make the temperature of the high-temperature gasification product stream to be truly decreased, but which temperature is still higher than the operating temperature of the pyrolyzer. By way of example, in the case of the temperature of the gasification product stream is for example 1200 to 1600 degrees Celsius, partially quenching of this gasification product stream will result in the temperature of the same ranging of below 950 degrees Celsius, particularly below 900 degrees Celsius, preferable below 800 degrees Celsius, more preferably below 750 degrees Celsius, which is still higher than that of the pyrolyzer in the range of 300 to 700 degrees Celsius.

The temperature for "partially quenching" or "partially quenched" is not specially limited herein, however, it should be understood to be the temperature under which gasification product stream including syngas stream and liquid slag is sufficiently cooled so as for the liquid slag therein to be converted into solid or even lower temperature

As shown in Figure 1, as the first exemplary embodiment according to the present invention, a system for producing solid, liquid and gas products from coal, mainly comprising crusher and optional dryer 10, pyrolyzer 20, gasifier 30, quench unit 40 and solid -gas separator 50 including cyclone and filter, within which high-temperature gasification product stream 37 is partially quenched by additionally adding water into the quench unit 40 via water line 41, and then after separation for freeing of solid fly ash 51 via the solid-gas separator 50 the resultant temperature-decreased pure syngas 52 is recycled into pyrolyzer 20 to provide heat for pyrolysis reaction and makes the operation temperature of the pyrolysis 20 keep into range required by pyrolysis reaction.

The coal 11 may be conveyed to the crusher and optional dryer 10 as shown in Figure 1 along a conventional continuous conveyor belt (not shown), by a skip hoist, a vibratory conveyor, pneumatically or in any other suitable manner. The coal 11 useful in the present invention can be of any types of raw coal, petrolic coke, and /or carbonaceous biomass. The crusher and optional dryer 10 used herein are conventional and well known in the art. The crusher 10 firstly crushes or grinds the coal 11 fed in into suitable particle size. The optional dryer then heats the finely divided coal to reduce the moisture content of the coal. The temperature of the coal is generally controlled below approximately 120 degrees Celsius so that no significant amounts of methane and/or carbon monoxide are released from the coal.

In fact, the particle size distribution (PSD) of finely divided and optional dried coal depends on requirement of the gasifier 30, various type of coal gasifier has different requirement on the above PSD, generally, its particle diameter preferably ranges from powder size to several decimeters. It need to advert that coal 11 could be not subjected to be dried, in that way, the moisture carried by coal 11 will be removed in the pyrolyzer 20.

The finely divided and optionally dried coal is pressurized by first lock hopper system 21, and then is fed into the pyrolyzer 20 which is pressurized vessel with general pressure of below 55 bar. The time when the coal resides in the pyrolyzer 20 generally ranges from about 15-45 minutes, especially about half hour.

First lock hopper system 21, together with second lock hopper system 31 that will be mentioned below, are well known by a person skilled in the art and are commercially available. Herein, the pyrolyzer 20 is pressurized to a pressure of preferably about 5 bars lower than that of gasifier 30, i.e. to a pressure of about below 55 bars, more preferably below 50 bar, most preferably about 25-45 bars.

The coal takes part pyrolysis reaction in the pyrolyzer 20 as to be removed of moisture and volatile substance therein to thus produce char and pyrolysis gas stream, the pyrolysis gas stream contains CO, H2, C02, CH4, H20, and H2S etc.

Within pyrolyzer 20, the temperature of the coal and its residence time in pyrolyzer 20 are controlled to achieve certain desired properties of the coal, e.g. lower relative sulphur content and higher relative carbon content. Preferably, the temperature of the coal is in the range of 300 to 700 degrees Celsius. During the processing of the coal in pyrolyzer 20 almost all remaining free moisture therein is removed, and a chemical reaction occurs resulting in producing pyrolysis gas stream and forming char 26 and 29. Pyrolyzer 20 may be of any type known in the art such as a batch type pyrolyzing furnace or a continuous type pyrolyzing furnace, and preferably a pyrolyzer of fluidization bed type. According to the present invention, preference is given to the continuous type pyrolyzing furnace. For a more detailed discussion of pyrolyzers useful in pyrolysis reaction, reference is made to US Patent 4924785, which is incorporated herein in integrity by reference.

Mixture 22 of the pyrolysis gas stream generated in the pyrolyzer 20 and syngas stream generated in the gasifier 30 under about 300 to 700 degrees Celsius is then subjected to further treatment in tar recovery unit 23 of any suitable type and separated therein into final syngas 24 and tar 25 in any suitable manner. The above tar recovery unit 23 may be preferably a condenser. The final syngas 24 thus obtained may be further processed or brought into use as generally in the industry practice. In this case, nearly 90 percent by weight of the tar is condensed and obtained, which also can be further processed as usually in the industry practice. In optional or selective case, Char 26 - portion of char generated in pyrolyzer 20 could be subjected to deactivation cooling in deactivation cooler 27 to afford upgraded coal 28. For example, 1/4-3/4 char, preferably 1/4-1/2 char generated in pyrolyzer 20 could be fed into the deactivation cooler 27 for getting the upgraded coal 28.

Furthermore, char 29-residue portion of char produced in pyrolyzer 20 is further pressurized by the second lock hopper system 31, and is then fed into gasifier 30. Generally, the time when the char 29 resides into the gasifier 30 could range from several seconds to several dozen seconds.

Herein, the gasifier 30 is pressurized to a pressure of preferably about 5 bars higher than that of pyrolyzer 20, i.e. to a pressure of preferably about below 60 bars, more preferably about below 55bar, most preferably about 30-50 bar.

As used herein, gasifier 30 can be of any feed gasifier conventional and well known in the art, such as the Shell dry feed gasifier. For another exemplified gasifier useful in the present invention, reference is made to US Patent 7037473, which is incorporated herein as whole by reference. The char 29 to be gasified inside gasifier 30, oxygen and/or oxygen-containing gas 32, especially oxygen-enriched air or oxygen generated by an Air Separation Unit (ASU), could be introduced into gasifier 30 at the top of the gasifier 30. Since the hot char 29 rather than all the coal is gasified within gasifier 30, therefore the oxygen consumption of gasifier 30 will be much lower, and the costly Air Separation Unit to be equipped also will be much smaller. Steam 33 can be optionally fed at the top of gasifier 30 into gasifier 30. The char 29 entering into gasifier 30 via the second lock hopper system 31 from pyrolyzer 20 is carbonaceous in nature, which could reacts with oxygen 32 and/or optional steam 33 under high temperature and high pressure to produces syngas containing CO, H2, C02, CH4, H20, and H2S etc, as well as liquid slag. Gasification product stream 37 substantially consisting of carbon monoxide, carbon dioxide, hydrogen (produced in the case of steam 33 being fed into gasifier 30) and the liquid slag is generally discharged out of gasifier 30 from the opening at its bottom. Due to the exothermic combustion happened in gasifier 30, its temperature rapidly increases to about 1200 to 1600 degrees Celsius. To prevent the temperature of internal wall of gasifier 30 from being too high and protect the internal wall of gasifier 30 from being overheated, gasifier 30 itself is equipped with water cooler 34 to cool its internal wall. Out-going steam 36 originally from in-coming cooling water 35 after heat exchange can be recycled into gasifier 30 as steam 33.

Gasification product stream 37 could be then subjected to quenching, preferably partially quenching by additionally adding water into in quench unit 40 via water line 41. More preferably, water is additionally sprayed into the quench unit 40 via nozzles and water line 41. In this case, quench mainly serves to partially cool down the syngas and slag and to reduce the requirements on the downstream equipments. During the course of partially quenching, the temperature of gasification product stream 37 can be decreased to below 950 degrees Celsius, such as preferably below 900 degrees Celsius, more preferably about 700-900 degrees Celsius, most preferably about 750-900 degrees Celsius form 1200-1600°C . The slag from the quench unit 40 is then fed into water quench tank 45 for water quench treatment, water-quenched slag 47 will ultimately be discharged from the water quench tank as shown by Figure 1. The steam resulting from above said water quench treatment can also be recycled into gasifier 30 as steam 33, or recycled for other uses, such as acting as heating gas stream for pyrolyzer 20. In the circumstance of high temperature up to 1600 degrees Celsius, steam additionally added into the gasifier 30 would further react with char and/or gasification product stream 37 to produce more hydrogen and methane. Temperature-decreased syngas 48 after being quenched or partially quenched and separation from the slag is then fed into solid-gas separator 50 from the quench unit 40 for separation between pure syngas 52 and solid fly ash 51, the solid-gas separator could preferably be a cyclone, cyclone cascade, membrane and/or filter.

It is should be noticed that the temperature of water used for the quench unit 40 and water quench tank 45 could be generally below 150^°C, in some specific cases, the pressurized water could be preferably used. The amount or rate of water used in the above both apparatuses should ensure that the temperature of syngas 48 and slag 47 originally from the gasifier 30 could be lowered to below about 950^°C from 1200-1600^°C and below about 150^°C from below about 950°C, respectively in the short time, for example from several second to several minute.

The solid-gas separator 50 could be a common device for separating solid or liquid off from gas and is well known in the art. With the aid of solid-gas separator 50, temperature-decreased syngas stream 48 is separated into solid fly ash 51 and pure syngas 52. The fly ash 51 getting down to the bottom of separator 50, for example dip-lag of the cyclone will be further quenched with water at lower portion of the solid -gas separator 50 including cyclone before it gets into the bottom of separator 50, for example the dip-leg of cyclone so as to avoid the plug of the bottom of separator 50, for example the dip-leg of the cyclone. Water quenched fly ash will be rejected from solid -gas separator 50 including cyclone via a standard lock hopper which is the same as those commonly used in today's industry practice. The hot steam generated from the water quenching of the hot fly ash can also be sent to gasifier 30 as steam 33, or recycled for other uses, such as acting as heating gas stream for pyrolyzer 20. The amount or rate of water for quenching hot fly ash should ensure that temperature of fly ash could be lowered to below about 150^°C from below about 950^°C in the short time, for example from several minutes to half hour. The hot pure syngas 52, under below about 950^°C, coming out of solid-gas separator 50, such as a cyclone would be recycled via pure syngas line 53 into the pyrolyzer 20, preferably into the lower portion or bottom of the pyrolyzer 20 immediately or promptly. Heat exchange will then happen in pyrolyzer 20 between recycled pure syngas 52 and the finely divided and optionally dried coal so that most of the heat entrained by recycled pure syngas 52 is transferred therefrom to the coal to be pyrolyzed. After completing heat exchange, the mixture 22 of recycled pure syngas stream and pyrolysis gas stream could be discharged from pyrolyzer 20, and subsequently separated in tar recovery unit 23 into final syngas 24 and tar 25.

As above described, in this way, the above system could realize entire circulation, between pyrolyzer and gasifier, of heat generated in the above system and achieve calorific balance without feeding of heat of any external heat resource into the above system.

In order for the pyrolyzer 20 to keep its operation temperature and pressure required by pyrolysis reaction, it is necessary that amount, temperature, or rate of coal 11 , char 29 and 26, pure syngas stream 52 and mixture 22 of pyrolysis gas stream and pure syngas stream, as well as parameters of the first lock hopper system are adjusted, one or more or even all of them could be adjusted to reach the above purpose. It is easy and obvious to person skilled in the art or science to which the field of chemical processing and engineering pertains.

In the same way, in order for the gasifier 30 to keep its operation temperature and pressure required by gasification reaction, it is necessary that amount, temperature, or rate of char 29, oxygen-containing gas or oxygen 32, optional steam 33 and gasification product gas 37, as well as parameters of the second lock hopper system are adjusted, one or more or even all of them are adjusted to reach the above purpose. For example, The amount of the above oxygen contain gas or oxygen 32 could be about 10-30 weight %, preferably about 15 weight % the char 29 on the basis of pure oxygen, meanwhile the amount of the above steam 33 could be 800-1200, preferably 1000 cubic meter/ton of the char 29.

In addition, in order to feed the finely divided and optional dried coal into the pyrolyzer 20, and feed char 29 into the gasifier 30, the pressure in the first lock hopper system 2 land the second lock hopper system31 should be higher than or same as the operation pressure in the pyrolyzer 20 or the gasifier 30 respectively.

As shown in Figure 2, as the substitute of first exemplary embodiment according to the present invention, the recycled syngas 43-i.e. portion of the final syngas 24 from the tar recovery unit 23 could be fed into the quench unit 40 for quenching or partially quenching the gasification product stream 37 via line 44 of recycled syngas 43 meanwhile water also could be optionally fed into the quench unit 40 for quenching or partially quenching via water line 41. The recycled syngas 43 could be pressurized by a gas compressor 42 and have temperature about ranging of room temperature - 250 ^°C before entering into the quench unit 40. By the effect of the recycled syngas 43 and /or water, the temperature of the syngas 48 from the quench unit 40 could be decreased into about below 950^°C from 1200-1600^°C. As shown in Figure 4, according to the second exemplary embodiment according to the present invention, a system for producing solid, liquid and gas products from coal is provided. The difference between the above first exemplary embodiment or its substitute and the present second exemplary embodiment is that the second lock hopper system 31 is replaced by a slurry tank 55 and pump 57 connected to the above slurry tank 55. Water could be fed into the slurry tank 55 to form water-char slurry together with char 29, the water -char slurry could be further pressurized by the above pump 57 and then could be fed into the gasifier 30. Water for slurry tank 55 could have the temperature about ranging from the room temperature to 150°C, in some specific cases, the pressurized water could be applied, and its temperature would be much higher than 120^°C .

The above water-char slurry has char/water volume ratio of preferably about 0.5-0.7/0.5-0.3, more preferably about 0.6/0.4 and preferably about 30-50 bar, more preferably about 40 bars pressure. The char 29 from the pyrolyzer 20 generally has temperature ranging from about 300-700 ^°C, in order to form the above water-char slurry with the above char/water ratio and the above pressure, char 29 from the pyrolyzer 20 has to be cooled by a well known cooler or heat exchanger (not shown in Figure 4) to reach below about 300 ^°C , the heat or steam generated from above said cooling treatment can also be recycled into gasifier 30 as steam 33, or can be used for, such as heating gas stream for pyrolyzer 20.

In another way, water in about two-four times, preferably three times of amount of water required by formation of the above water-char slurry with the above char/water volume ratio and the above pressure could be fed into the slurry tank 55, therefore producing the above water-char slurry and steam with high temperature of about 150^°C and high pressure of about 30-50 bars preferably 40 bar, and the amount of the above steam could be several times, preferably about double of that of water required by the above water-char slurry. In this case, the above cooler or heat exchanger could be deleted from the above system, and high temperature and high pressure steam generated in the above process could also be recycled into gasifier 30 as steam 33, or can be used for, such as heating gas stream for pyrolyzer 20.

As shown in Figure 5, according to the third exemplary embodiment according to the present invention, a system for producing solid, liquid and gas products from coal is provided. The difference between the above second exemplary embodiment and the present third exemplary embodiment is that the quench unit 40 is deleted from the system according to present invention, instead of, quench media could be sprayed into area nearby outlet of the syngas stream inside of the gasifier for quenching syngas stream, in this way, syngas 48, under below about 950^°C from the gasifier 30, after gas-solid separation is directly fed into the pyrolyzer 20. The above quench media could preferably be syngas, water and /or carbon dioxide etc, their amount, rate, and temperature should ensure that temperature of syngas 48 could is lowered to below about 950°Cfrom 1200^°C-1600^°C .

The syngas generated in the gasifier 30 could go upstream, that means that the water-char slurry, oxygen containing gas and /or oxygen, and/or optional steam could be fed into the gasifier 30 from its lower portion, and syngas 48 could be discharged out of the gasifier 30 from its upper portion. Meanwhile the slag generated in gasifier 30 could still be discharged from the bottom of the gasifier 30 for water quenching treatment.

As shown in Figure 3, according to the fourth exemplary embodiment according to the present invention, a system for producing solid, liquid and gas products from coal is provided. The difference between the above third exemplary embodiment and the present fourth exemplary embodiment is that the slurry tank 55 and pump 57 connected to the above slurry tank 55 is replaced by a second lock hopper system 31.

In the fourth exemplary embodiment according to the present invention, the parameters for the second lock hopper system 31 is described as aforesaid, for clarity and simplified expression, more detailed description about it is herewith omitted.

As shown in Figure 6, as the another substitute of first exemplary embodiment according to the present invention, said above system could further comprise a syngas burner 60 for combusting a portion of the final syngas 24 from said tar recovery unit 23 and then feeding combusted product into the pyrolyzer 20 to provide with heat required by pyrolysis reaction.

It must be said that the above syngas burner 60 is optional or selective, and it is very useful at starting stage of operation of the above system according to the present invention or when the operation of the above system meets technical or mechanical difficulties.

The above coal is referred to all types of coal, carbonaceous biomass (bio-substance), petrolic coke, carbonaceous solid wastes and /or carbonaceous mud and slag etc.

In the case wherein steam was fed into the gasifier, more CO and H2 would be shifted to drive the downstream hydro-gasification reaction if high temperature sour shift catalyst for water-gas reaction was added into the pyrolyzer or the gasifier, for example into the bottom of the pyrolyzer.

If the direct coal liquefaction catalyst, for example FeS was added into the pyrolyzer under high temperature and high pressure, tar gas in the pyrolyzer could react with the above catalyst to produce hydrogenated tar, i.e. synthetic oil. The above synthetic oil could be recovered by the above well known tar recovery unit, and yield of the above oil was higher than that of tar.

In the above case, mixture of pure syngas stream and pyrolysis gas stream generally contains common components of syngas, methane, and light hydrocarbon such as C1-C2 and C3, etc. Such mixture could pass either a methanation catalyst bed to form real SNG, or passes an F-T type of catalyst bed to convert the syngas components to hydrocarbon liquid or methanol. The another option is to separate the hydrocarbon out, and the left syngas components could all shift to H2 for downstream further upgrading hydrocarbon liquid to better fuels.

Example

Example 1

Now with reference to Figure 1, the following example 1 according to the above first exemplary embodiment is provided with.

Raw soft coal was crushed by the well known crusher into particle size distribution (PSD) following below:

Particles diameter of 99 weight% coal < 250 um;

Particles diameter of 100 weight% coal < 500 um;

and was dried by the well known drier to moisture content of below 12 weight %; ash substance content >1 weight%, the melting temperature of the ash substance <1500^°C ; the coal calorific value was about 20900 joule/gram . The temperature of dried coal was below 120^°C, the heat source of the drier was the hot gas from pyrolyzer or quench unit etc.

The above finely divided and dried coal was firstly fed into the well know the first lock hopper system, and was pressurized to little higher than 35 bar, for example 36 or 37 bar, and was then fed into well known pyrolyzer of fluidization bed type for pyrolysis reaction. The pyrolyzer had operation pressure of about 35 bar, and operation temperature of about 350-400 ^°C .

At the initial stage of operation of the pyrolyzer, the above pyrolyzer was heated to about 350-400°C by any external heat resources, for example, high temperature and high pressure syngas being sprayed into the pyrolyzer via combustion nozzles. Once the heat provided with by pure syngas originally from the gasifier was fed into the pyrolyzer together with pure syngas and was enough to support on continuation of pyrolysis reaction at 350-400°C, the feeding of such heat from the external source was terminated immediately.

Under temperature of about 350-400^°C and pressure of about 35 bar, finely divided and dried coal took part pyrolysis reaction to produce pyrolysis gas stream and char. Time when the finely divided and dried coal resided into the pyrolyzer was about half hour.

About 2/3 char from pyrolyzer was fed into well known second lock hopper system, to be further pressurized to little higher than 40 bar, for example 41 or 42 bar, and was then fed into GSP type gasifier for gasification reaction, other 1/3 char from the pyrolyzer was cooled by any well known deactivation - cooler to below 75 ^°C for getting chemically stable upgraded coal, its calorific value was measured to reach about 28000 joule/gram. The calorific value of the coal thus by pyrolysis reaction was greatly enhanced. In addition to adding char from the second lock hopper system into the gasifier, oxygen and steam were also fed into the gasifier by using mixed nozzles, the gasifier had the operation temperature of about 1430°C and operation pressure of about 40 bar. At the initial stage of operation the gasifier, the gasifier was heated by its combustion nozzles to about 1430^°C . The char fed into gasifier of high temperature and high pressure vessel took part gasification reaction to produce gasification product stream including syngas stream and liquid slag. The time when the above char resided into the gasified was about 2-10 seconds

The amount of the above oxygen was about 15 weight % the above char from second lock hopper system on the basis of pure oxygen, meanwhile the amount of the above steam was about 1000 cubic meter/ton of the char from second lock hopper system. The gasification product stream, under about 1430°C and about 40 bar, was then fed into the quench unit for partial quenching from the gasifier, meanwhile water at about 150^°C was sprayed into the quench unit via high pressurized nozzles and water line, and the amount of the above water should ensure that the temperature of the gasification product stream including syngas stream and liquid slag was lowered to about 800 °C from about 1430°C, steam generated in partial quenching could be reused for any other applications. The liquid slag was cooled to be converted into glassy solid during quench, was then fed into the water quenching tank for water quenching treatment, water quenched slag was finally discharged from water quenching tank by a lock hopper. And steam generated during water quenching treatment could also be reused for any other applications.

The syngas stream separated from liquid slag under about 800 ^°C was then fed into a well known industrial cyclone for separation from fly ash, and hot fly ash separated from syngas stream was then also quenched at lower portion of the cyclone by water before it reach into the dip-leg to avoid the plug of the cyclone dip-leg. In the same way, steam generated during water quenching treatment of fly ash could also be reused for any other applications, for example, was used to dry the above raw soft coal.

The pure syngas stream separated from fly ash at about 800 ^"C was fed into the pyrolyzer, and its amount should ensure the operation temperature and pressure of the pyrolyzer kept at about 350-400 ^°C and 35 bars respectively.

After heat exchange between pure syngas stream and finely divided and dried coal, the temperature of the pure syngas stream was decreased to about 350- 400 ^°C from about 800 °C, and forming mixture of pure syngas stream and pyro lysis gas stream generated in the pyrolyzer.

The mixture of pure syngas stream and pyrolysis gas stream was then discharged from the pyrolyzer and fed into a well known tar recovery unit including a condenser to be separated into final syngas and tar. The above condenser cooled the above mixture to about 25-85 ^°C to be separated into final syngas and tar containing water. Depending on condensation temperature, the moisture content in the tar could change to the extent.

The process parameters and limitations to raw materials for pyrolyzer and gasifier depended on the requirement prescribed by the specific type of the pyrolyzer and gasifier, generally, such data was obvious for any skilled worker, and readily available via reviewing the operation handbook for the pyrolyzer and gasifier and regarding references or literatures in the prior art.

On the basis of weight % of the following components, the raw soft coal had the chemical composition as following:

Table 2

Counting on the dry basis; the calorific value of the raw soft coal was about 20900 joule/gram.

On the basis of weight % of the following components, the resultant upgraded coal had the chemical composition as following:

Table 3

The calorific value of the upgraded coal was about 28000 joule/gram.

On the basis of mole % of the following components, the resultant final syngas had the chemical composition as following:

Table 4

The calorific value of the final syngas was 15700 kilojoule/cubic meter.

On the basis of weight % of the following components, the resultant tar had the or chemical substance composition as following:

Table 5

By elements analysis, on the basis of weight % of the following elements, the resultant tar had the elements composition as following:

Table 6

PT is referred to the pyrolysis temperature;

In the above example 1 , the gasification carbon conversion rate was about 99.5%; the gasification efficiency rate was about 81.5%; the heat efficiency rate for gasification was about 97%. Example 2

Now with reference to Figure 5, the following example 2 according to the above third exemplary embodiment is described in detail.

In example 2, the raw soft coal and limitation to it were the same as in example 1, and the operation temperature and pressure of the pyrolyzer of fluidization bed type were about 450-500 ^°C and about 40 bars respectively, on the other hand, the operation temperature and pressure of typical gasifier wherein water-coal slurry feeding went upstream, for example the E-gas type gasifier, were about 1480°C and about 45 bars respectively. The time when the finely divided and dried coal resided into the pyrolyzer was about 27 minutes.

The about 3/4 char from the pyrolyzer was fed into the slurry tank at about 40 bars to form water-char slurry with char/water volume ratio of 0.6/0.4, and water in amount of about three times of that of water required by formation of the water-char slurry with the above char/water volume ratio was added into the above slurry tank wherein 2/3 water became steam at high temperature and high pressure, such steam could be reused for any heating or quenching, for example as quench media for syngas generated in the gasifier. The resultant water-char slurry was then fed into the gasifier from its lower portion together with oxygen via pump and mixed nozzles.

The time when the above water-char slurry resided into the gasifier for gasification reaction was about 4-8 seconds. The syngas stream generated in the gasifier went upstream to reach the top of the gasifier and exited from the said top, therefore there was one outlet of syngas stream at the said top, and pressurized water stream at about 45 bars and about 150°C as quench media was prayed the area nearby the above outlet of the syngas stream inside of the gasifier, the above water amount should ensure that the syngas stream temperature was lowered to about 850-900^°C from about 1480°C . Then the temperature decreased syngas stream out of the gasifier was directly fed into the cyclone for separation between pure syngas and fly ash or residue of slag.

Other about 1/4 char from the pyrolyzer was cooled by well known deactivation-cooler to about 75 'C to thus become chemically stable upgraded coal.

On the basis of weight % of the following components, the above upgraded coal had the chemical composition as following:

Table 7

The calorific value of the upgraded coal was about 28500 joule/gram.

Table 8

CO H2 C02 CH4 H2S H20

32.3-42.4 22.8-26.2 12.7-13.9 3.5-5.6 0.9-1.1 17.7-20.9 The calorific value of the final syngas was 17700 kolijoule/cubic meter.

On the basis of weight % of the following components, the resultant tar had the major chemical substance composition as following:

Table 9

Table 10

referred to the pyrolysis temperature.

The necessary parameters and dates for pyrolysis and gasification processes which were not identified in the example 2 were the same as that in the example 1 unless otherwise stated.

In the above example 2, the gasification carbon conversion rate was about 99.7%; the gasification efficiency rate was about 82.3%; the heat efficiency rate for gasification was about 98.3%.

Example 3

Now with reference to Figure 1, the following example 3 according to the above first exemplary embodiment is provided with.

Raw lignitic coal, which of moisture content was about 31 weight%, was crushed by the well known crusher into particle size distribution (PSD) following below:

Particles diameter of 80 weight% coal < 250 um;

Particles diameter of 100 weight% coal < 500 um;

The above lignitic coal had calorific value of 19.33MJ/Kg identified by analysis and was dried by the well known drier to moisture content of below 8 weight %. The temperature of dried coal was below 150^°C, the heat source of the drier was the hot gas from pyrolyzer or quench unit etc.

The above finely divided and dried coal was firstly fed into the well know the first lock hopper system on the flow rate of 100-120 tons/hour, and was pressurized to little higher than 35 bar, for example 36 or 37 bar, and was then fed into well known pyrolyzer of fluidization bed type for pyrolysis reaction. The pyrolyzer had operation pressure of about 35 bar, and operation temperature of about 350- 400 ^°C .

At the initial stage of operation of the pyrolyzer, the above pyrolyzer was heated to about 350-400 °C by any external heat resources, for example, high temperature and high pressure syngas being sprayed into the pyrolyzer via combustion nozzles. Once the heat provided with by pure syngas originally from the gasifier was fed into the pyrolyzer together with pure syngas and was enough to support on continuation of pyrolysis reaction at 350-400 ^°C, the feeding of such heat from the external source was terminated immediately.

Under temperature of about 350-400 °C and pressure of about 35 bar, finely divided and dried coal took part pyrolysis reaction to produce pyrolysis gas stream and char. Time when the finely divided and dried coal resided into the pyrolyzer was about half hour. By pyrolysis reaction, about 65-75 tons /hour tar were produced, which of calorific value was enhanced to 24-26MJ Kg, and the volatiles content therein was lowered to 15-20 weight%.

About 47-52 tons/hour char from pyrolyzer was fed into well known second lock hopper system, to be further pressurized to little higher than 40 bar, for example 41 or 42 bar, and was then fed into a gasifier for dry coal powder feeding, for instance gasifier of GSP type for gasification reaction, other 13-28 tons/hour char from the pyrolyzer was cooled by any well known deactivation - cooler to below 75 ^°C for getting chemically stable upgraded coal, its calorific value was measured to reach about 24.3MJ/Kg. The calorific value of the product i.e. the upgraded coal was greatly higher than the raw lignitic coal, and the stability and security for it were also enhanced so that it was very suitable for long distance transportation, in this way, the comprehensive value of the product is remarkably increased.

According to the present invention, the operation condition for the gasifier depended on the type of the gasifier, which was common general knowledge in the art. In the present example according to the invention, the typical operation condition was selected for the gasifier, however in practice, the operation condition could change a lot, depending on specific case.

In addition to adding char from the second lock hopper system into the gasifier, oxygen and steam were also fed into the gasifier by using mixed nozzles, the gasifier had the operation temperature of about 1430^°C and operation pressure of about 40 bars respectively. At the initial stage of operation the gasifier, the gasifier was heated by its combustion nozzles to about 1430^°C. The char fed into gasifier of high temperature and high pressure vessel took part gasification reaction to produce gasification product stream including syngas stream and liquid slag. The time when the above char resided into the gasified was about 3-10 seconds

The flow rate of the above oxygen was about 18-23 thousands standard cubic meter per hour on the basis of pure oxygen, meanwhile the flow rate of the above steam was about 8-12 tons/hour. The gasification product stream, under about 1430"C and about 40 bar, was then fed into the quench unit for partial quenching, meanwhile water at about 150^°C was sprayed into the quench unit via high pressurized nozzles and water line, and the amount of the above water should ensure that the temperature of the gasification product stream including syngas stream and liquid slag was lowered to about 800°C from about 1430^°C, steam generated in partial quenching could be reused for any other applications. Liquid slag was cooled to be converted into glassy solid during quench, was then fed into the water quenching tank for water quenching treatment, water quenched slag was finally discharged from water quenching tank by a lock hopper. And steam generated during water quenching treatment of slag could also be reused for any other applications.

The syngas stream separated from liquid slag under about 800 °C was then fed into a well known industrial cyclone for separation from fly ash, and hot fly ash separated from syngas stream was then also quenched at lower portion of the cyclone by water before it reach into the dip-leg to avoid the plug of the cyclone dip-leg. In the same way, steam generated during water quenching treatment of fly ash could also be reused for any other applications, for example, was used to dry the above raw lignitic coal.

The syngas stream produced in the gasifier was cooled to about 800 ^°C via partial quench, which of flow rate was about 110-150 thousands standard cubic meter/hour after partial quench, so as to become pure syngas at about 800 ^°C after separation from fly ash, was then fed into the pyrolyzer, and the operation temperature and pressure of the pyrolyzer kept at about 350-400 "C and 35 bars respectively.

After heat exchange between the pure syngas stream and finely divided and dried coal, the temperature of the pure syngas stream was decreased to about 350- 400^°C from about 800 ^°C, and forming mixture of the pure syngas stream and pyrolysis gas stream generated in the pyrolyzer.

The mixture of the pure syngas stream and the pyrolysis gas stream was then discharged from the pyrolyzer and fed into a well known tar recovery unit including a condenser to be separated into final syngas and tar. The above condenser cooled the above mixture to about 25-85 ^°C to be separated into final syngas and tar containing water. Depending on condensation temperature, the moisture content in the tar could change to the extent.

By industrial analysis and elements analysis, on the basis of weight% of the following components, the raw lignitic coal had the chemical composition as following:

Table 11

Counting on the air dry basis

The calorific value of the lignitic coal was about 19.33MJ/Kg. By industrial analysis and elements analysis, on the basis of weight% of the following components, the resultant upgraded coal had the chemical composition as following:

Table 12

Counting on the air dry basis

The calorific value of the upgraded coal was about 24.3MJ/Kg. The calorific value was greatly enhanced via raw coal being upgraded.

On the basis of volume % of the following components, the resultant final syngas had the chemical composition as following:

Table 13

On the basis of weight% of the following components, the resultant tar had the major chemical substance composition as following:

Table 14

Table 15

PT was referred to the pyrolysis temperature

In the above example 3, in order to produce 1000 cubic meter effective syngas (C0+H2), about 310 cubic meter oxygen and about 570 Kg char had to be consumed. In comparison with data from GSP gasification where the same raw lignitic coal was applied in current industrial practice, i.e. consumption of over 360 cubic meter oxygen and over 670 Kg coal for production of 1000 cubic meter effective syngas (CO+H2), productive rate of the system according to the invention was remarkably enhanced, and high quality upgraded coal was produced.

Example 4

Now with reference to Figure 5, the following example 4 according to the above third exemplary embodiment is described in detail.

In example 4, the raw lignitic coal and limitation to it were the same as in example 3, and the operation temperature and pressure of the pyrolyzer of fluidization bed type were about 450-500 ^°C and about 40 bars respectively, on the other hand, the operation temperature and pressure of the typical gasifier wherein water-coal slurry feeding went upstream, for example E-gas type gasifier were about 1480^°C and about 45 bars respectively. The time when the finely divided and dried coal resided into the pyrolyzer was about 27 minutes.

About 38-43 tons/hour char from the pyrolyzer was fed into the slurry tank at about 40 bars to form water-char slurry with char/water volume ratio of 0.6/0.4, and water in amount of about three times of that of water required by formation of the water-char slurry with the above char/water volume ratio was added into the above slurry tank wherein 2/3 water became steam at high temperature and high pressure, such steam could be reused for any heating or quenching. The resultant water-char slurry was then fed into the gasifier from its lower portion together with oxygen via pump and mixed nozzles.

The time when the above water-char slurry resided into the gasifier for gasification reaction was about 4-8 seconds. The syngas stream generated in the gasifier went upstream to reach the top of the gasifier and exited from the said top, therefore there was one outlet of syngas stream at the said top, and pressurized water stream at about 45 bars and about 150^°C as quench media was prayed the area nearby the above outlet of the syngas stream inside of the gasifier in the flow rate of 21-25 tons /hour, thereby the syngas stream temperature was lowered to about 850-900 ^°C from about 1480^°C . Then the temperature decreased syngas stream out of the gasifier was directly fed into the cyclone for separation between pure syngas and fly ash or residue of slag.

Other residue char from the pyrolyzer was cooled by well known deactivation-cooler to about 75 °C to thus become chemically stable upgraded coal.

By industrial analysis and elements analysis, on the basis of weight% of the following components, the above upgraded coal had the chemical composition as following:

Table 16

Counting on the dry basis

The calorific value of the upgraded coal was about 26.5MJ/Kg. The calorific value was greatly enhanced via raw coal being upgraded.

Table 17

CO H2 C02 CH4 H2S H20

28.3-35.4 20.8-24.2 8.7-13.9 3.5-5.6 0.9-1.1 35.7-40.9 The calorific value of the final syngas was 25-28MJ/Kg.

On the basis of weight % of the following components , the resultant tar had the major chemical substance composition as following:

Table 18

Table 19

PT was referred to the pyrolysis temperature

The necessary parameters and dates for pyrolysis and gasification processes which were not identified in the example 4 were the same as that in the example 3 unless otherwise stated.

In the above example 4, in order to produce 1000 cubic meter effective syngas (CO+H2), about 350 cubic meter oxygen and about 560 Kg char had to be consumed. Because of poor properties of the lignitic coal including high moisture content therein and poor ability to form slurry, the lignitic coal could not be applied into water-coal slurry feeding pressurized gasifier, for example GE type gasifier, gasifier having multiple opposite nozzles, and E-gas type gasifier in the current industrial practice. For the gasifier where the higher quality soft coal is applied, in present industrial practice, about 390-450 cubic meter oxygen and about 550-650 Kg coal have to be consumed for production of 1000 cubic meter effective syngas (CO+H2), in contrast, the system according to the invention not only could apply poor quality lignitic coal, but also remarkably improve technical index while producing high quality upgraded coal.

The chemical or elements compositions for the above soft coal, lignitic coal, upgraded coal, syngas gas and tar were measured by any methods well known by those skilled in the art, for example, they were measured by Spectroscopic Methods, Industrial Analysis Method and/or Element Analysis Method.

Although a few embodiments of the present invention have been shown and described, the present invention is not limited to the described embodiments. Instead, it would be appreciated by those skilled in the art that any changes and modification may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A system producing solid, liquid and gas products from coal, comprises:

i) coal crusher and optional coal dryer;

ii) first lock hopper system

iii) coal pyrolyzer;

iv) second lock hopper system

v) coal gasifier ;

vi) tar recovery unit connected to the pyrolyzer;

is characterized in that said system further comprises:

vii) quench unit;

viii) solid - gas separator;

said above components i)-v) and vii)-viii) are communicated in turn by line, ix) line, passing through the quench unit and the solid - gas separator, for communicating the gasifier with the pyrolyzer ; and

wherein the line for communicating the gasifier with the pyrolyzer and the quench unit allow that syngas from the solid-gas separator or gasifier is fed into the pyrolyzer, that thus guarantees controlling operation temperature of the pyrolyzer into range desired by pyrolysis reaction without external heat source for the pyrolysis reaction.

2. The system according to claim 1, wherein said quench unit is a partially quenching unit where the temperature of gasification product stream including syngas stream and liquid slag is sufficiently decreased so as for the liquid slag therein to be converted into solid or even lower temperature.

3. The system according to claim 2, wherein said partially quenching unit comprises line and nozzles for additionally adding water into this unit.

4. The system according to claim 2, wherein said partially quenching unit comprises line and nozzles for feeding portion of syngas from the tar recovery unit into said quench unit.

5. The system according to claim 4, wherein said partially quenching unit comprises line and nozzles for additionally adding water into this unit.

6. The system according to claim 1, wherein said second lock hopper system is replaced by a char slurry tank and pump connected to the tank.

7. The system according to claim 6, wherein water is added into said char slurry tank to form char slurry.

8. The system according to any one of aforesaid claims 1-7, wherein said solid - gas separator is a cyclone, cyclone cascade, membrane and/or filter.

9. The system according to any one of aforesaid claims 1-7, further comprises a coal deactivation cooler connected to line between the pyrolyzer and the second lock hopper system or the coal slurry tank to cool portion of char from pyrolyzer to produce upgraded coal.

10. The system according to any one of aforesaid claims 1-7, wherein said tar recovery unit is a condenser.

11. The system according to any one of aforesaid claims 1-7, wherein slag generated in the gasifier is finally discharged into water tank for water quench treatment.

12. The system according to any one of claims 1-7, said system further comprises a syngas burner for combusting a portion of the syngas from said tar recovery unit and then feeding combusted product into the pyrolyzer to provide with heat to pyrolysis reaction.

13. The system according to any one of claims 1-7, wherein said gasifier comprises oxygen and /or air inlet and optional steam inlet.

14. A system producing solid, liquid and gas products from coal, comprises: i) coal crusher and optional coal dryer;

ii) first lock hopper system

iii) coal pyrolyzer;

iv) slurry tank

v) pump

vi) coal gasifier ;

vii) tar recovery unit connected to the pyrolyzer;

is characterized in that said system further comprises:

viii) quench unit;

ix) solid - gas separator;

above said components i)— i) and viii)-ix) are communicated in turn by line, x) line, passing through the quench unit and solid - gas separator, for communicating the gasifier with the pyrolyzer ; and

wherein the line for communicating the gasifier with the pyrolyzer and the quench unit allow that syngas from the quench unit or gasifier is fed into the pyrolyzer, that thus guarantees controlling operation temperature of the pyrolyzer into range desired by pyrolysis reaction without external heat source for pyrolysis reaction.

15. A system producing solid, liquid and gas products from coal, comprises: i) coal crusher and optional coal dryer;

ii) first lock hopper system

iii) coal pyrolyzer;

iv) slurry tank

v) pump

vi) gasifier ;

vii) tar recovery unit connected to the pyrolyzer;

is characterized in that said system further comprises:

viii) solid - gas separator;

above said components i)— vi) and viii are communicated in turn by line, ix) line, passing through the solid-gas separator, for communicating the gasifier with the pyrolyzer ; and

wherein the line for communicating the gasifier with the pyrolyzer and spraying quench media into area nearby outlet of the syngas inside of the gasifier for quenching syngas stream allow that syngas from the gasifier is fed into the pyrolyzer, that thus guarantees controlling operation temperature of the pyrolyzer into range desired by pyrolysis reaction without external heat source for pyrolysis reaction.

16. A system producing solid, liquid and gas products from coal, comprises: i) coal crusher and optional coal dryer;

ii) first lock hopper system

iii) coal pyrolyzer;

iv) second lock hopper system

v) coal gasifier ;

vi) tar recovery unit connected to the pyrolyzer;

is characterized in that said system further comprises:

vii) solid - gas separator;

said above components i)-v) and vii) are communicated in turn by line,

wherein the line for communicating the gasifier with the pyrolyzer and spraying quench media into area nearby outlet of the syngas inside of the gasifier for quenching syngas stream allow that syngas from the gasifier is fed into the pyrolyzer, that thus guarantees controlling operation temperature of the pyrolyzer into range desired by pyrolysis reaction without external heat source for the pyrolysis reaction.

17. The system according to any one of claims 1, 14-16, wherein said pyrolyzer has operation temperature ranging from 300-700 "C and operation pressure that is not more than 99 bar.

18. The system according to any one of claims 1, 14-16, wherein said gasifier has operation temperature ranging from 1100-1700 ^°C and operation pressure that is not more than 100 bar.

19. The system according to any one of claims 1, 14-16, wherein the operation pressure of said pyrolyzer is 1-5 bar(s) lower than that of said gasifier.

20. The system according to any one of claims 1, 14-16, wherein the syngas after solid-gas separation enters into said pyrolyzer under temperature of below 900 ^°C.

21. The system according to any one of claims 1, 14, wherein the quench unit is deleted, and quench media is sprayed into area nearby outlet of the syngas inside of the gasifier.

22. The system according to claim 21 , wherein said quench media comprises water, syngas, and/or carbon dioxide.

23. A method for producing solid, liquid and gas products from coal by using the system according to any one of aforesaid claims 1-22, comprises following the steps in turn:

a) crushing and optional drying the coal to get finely divided and optionally dried coal

d) the char generated in the pyrolyzer being fed into the second lock hopper system for further pressurization of the char or into the slurry tank;

e) the further pressurized char or char slurry pressurized by the pump being fed in the gasifier and gasifying said further pressurized char or said char slurry in the gasifier into syngas stream and slag;

f) the said syngas stream and slag being fed into the quench unit from the gasifier or spraying quench media into area nearby outlet of the syngas stream inside of the gasifier for quenching syngas stream to decrease temperature of the said syngas stream into range that is lower than operation temperature of the gasifier but higher than operation temperature of the pyrolyzer;

g) the slag optionally being fed into water tank from the quench unit or the gasifier for water quench treatment;

wherein the pure syngas is fed into the pyrolyzer, that thus guarantees controlling the operation temperature of the pyrolyzer into range desired by the pyrolysis reaction without external heat source for pyrolysis reaction.

24. The method according to claim 23, wherein said syngas stream is partially quenched in the quench unit.

25. The method according to claim 23, further comprises portion of the char from the pyrolyzer not being fed into the second lock hopper system or the slurry tank, otherwise being cooled for deactivation to get upgraded coal.

26. The method according to claim 23, wherein oxygen and /or air and optional steam being fed into the gasifier.

27. The method according to claim 23, wherein water and /or a portion of the final syngas from the tar recovery unit is fed into the quench unit for the syngas stream quench.

28. The method according to claim 23, wherein a portion of the final syngas from said tar recovery unit combusts and combustion product then is fed into the pyrolyzer to provide with heat to pyrolysis reaction.

29. The method according to claim 23, wherein the syngas stream in the gasifier is not fed into the quench unit while quench media is sprayed into area nearby outlet of the syngas inside of the gasifier to quench syngas stream, thereby the syngas stream from the gasifier is directly fed into the solid-gas separator.

30. The method according to claim 29, wherein the quench media comprises syngas, water, and /or carbon dioxide.

31. The method according to claim 23, wherein the syngas stream generated in the gasifier goes upstream or downstream in the gasifier.

32. The method according to claim 23, wherein particle size distribution of said finely divided and optionally dried coal depends on the gasifier's requirement.

33. The method according to any one of aforesaid claims 23-32, wherein a direct coal liquefaction catalyst is added into the pyrolyzer to convert the tar into synthetic oil.

34. The method according to claim 33, wherein the direct coal liquefaction catalyst is FeS or FeS(i-x₎, wherein 1-X is 0.7-0.9.

35. The method according to any one of aforesaid claims 23-32, wherein a high temperature sour shift catalyst for water gas reaction is added into the pyrolyzer and/or gasifier.