FORM -2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE
Specification
(See Section 10; rule 13)
GASIFICATION SYSTEM
THERMAX LIMITED
an Indian Company of D-13,MIDC indutrial Area,R.D. Aga Road, chinchwad,pune-411 019,
Maharashtra, India.
NAME OF THE INVENTOR
1. BASARGEKAR SUDHEER, SHYAMRAO
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE DISCLOSURE
The present disclosure generally relates to a gasification system.
Particularly, the present disclosure relates to a multistage gasification system.
BACKGROUND
Gasification is a thermo-chemical process in which a carbonaceous feedstock such as coal, biomass, and the like, is converted into a gaseous compound comprising mainly hydrogen and carbon monoxide, under oxygen depleted, high pressure, and high heat and/or steam conditions. The gaseous compound is called syngas (synthesis gas) or producer gas and can be directly used as a fuel. This syngas may be burned directly in gas engines/turbines, used to produce methanol and hydrogen, or converted via the Fischer-Tropsch process into synthetic fuel
In a gasification system using coal as the second portion k, the coal is fed in a gasifier and in the presence of limited oxygen it is gasified through several stages including dehydration, pyrolysis (chemical change brought about by heat), combustion, and gasification, to obtain a mixture of gas and char. The char may be recirculated to a combustion furnace for further combustion. The efficiency of a gasification process although largely depends upon the calorific value of the feedstock, constant efforts are being made to provide highly efficient gasification systems which convert the feedstock into clean

energy. One such approach to obtain highly efficient gasification systems is by complete gasification of the feedstock.
OBJECTS
Some of the objects of the system of the present disclosure, which at least one embodiment herein satisfies, are as follows:
It is an object of the system of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
An object of the system of the present disclosure is to provide a gasification system that provides complete gasification of feedstock.
Another object of the system of the present disclosure is to provide a gasification system that is comparatively more efficient.
Additionally, an object of the system of the present disclosure is to provide a gasification system that is simple in construction.
Furthermore, an object of the system of the present disclosure is to provide a gasification system that provides separation of combustion and gasification stages for optimization of each process.
Moreover, an object of the system of the present disclosure is to provide a gasification system that is easy to operate.

Other objects and advantages of the system of the present disclosure will be more apparent from the following description when read in conjunction with the accompanying figures which are not intended to limit the scope of the present disclosure.
SUMMARY
In accordance with one aspect of the present disclosure, a gasification system is disclosed. The gasification system includes a combustion chamber assembly and a gasification chamber assembly. The combustion chamber assembly includes a combustion chamber, a firing device and a distributor plate. The combustion chamber has a combustion bed. The firing device is provided in the combustion chamber and is adapted to facilitate combustion of a first portion of a feedstock and ash from a gasification chamber/a cyclone separator, fed inside the combustion chamber. The distributor plate is disposed inside the combustion chamber and adapted to facilitate supply of air/oxygen and steam to the combustion chamber. The gasification chamber assembly is connected to the combustion chamber assembly for facilitating flow of flue gas generated by combustion of the first portion of the feedstock and ash from the gasification chamber/the cyclone separator from the combustion chamber to the gasification chamber assembly. The gasification chamber assembly includes a gasification chamber and a distributor plate. The gasification chamber is connected to the combustion chamber for facilitating flow of flue gas generated by combustion of the first portion of the feedstock and ash from the gasification chamber / the cyclone separator, from the combustion chamber to the gasification chamber. The gasification chamber has a gasification bed and an inlet for facilitating

feeding of a second portion of the feedstock inside the gasification chamber. The distributor plate is disposed inside the gasification chamber. The gasification chamber assembly is adapted to convert the feedstock to syngas by utilizing the flue gases generated by combustion of the first portion of the feedstock and ash from the combustion chamber. Steam and additional air, is admitted via at least one inlet into the gasification chamber assembly through the distributor plate.
Typically, the combustion chamber assembly further includes an ash discharge device connected at the operative bottom of the combustion chamber for discharging ash contained in the combustion chamber.
In one embodiment, the combustion chamber assembly is maintained at a higher pressure as compared to the gasification chamber assembly.
Typically, the first portion of the feedstock is in the range of 0 to 15 % of the feedstock, depending on calorific value of the feedstock and the ash from the gasification chamber and/or the cyclone separator.
The combustion chamber may be operated at a temperature in the range of 800 to 1050 °C.
Typically, the second portion of the feedstock is in the range of 85 to 100 % of the feedstock depending on calorific value of the feedstock. The gasification chamber may be operated at a temperature in the range of 800 to 1050 °C.

In one embodiment, the feedstock is coal.
Alternatively, in another embodiment of the present disclosure the feedstock is biomass.
A cyclone separator may be connected after the gasification chamber assembly for separating ash carried over by the syngas.
In one embodiment, a plurality of supply lines is used for collecting ash from the gasification chamber and the cyclone separator to the combustion chamber, wherein each of the plurality of supply lines has an arrangement for preventing backflow of flue ash from the combustion chamber to the gasification chamber/ cyclone separator.
In one embodiment, the gasification system includes a cooling device for cooling the syngas generated in the gasification chamber.
Furthermore, the gasification system may include a cleaning device for cleaning the syngas generated in the gasification chamber.
Typically, the combustion bed is selected from the group consisting of fluidized bed and circulating bed.
Typically, the gasification bed is selected from the group consisting of fluidized bed and circulating bed.

Additionally, an inlet is provided at an operative bottom of the gasification chamber, the inlet being adapted to admit air, oxygen and steam into an operative top of the gasification chamber through the distributor plate of the gasification chamber.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWING
The disclosure will now be explained in relation to the non-limiting accompanying drawing, in which:
Figure 1 illustrates a schematic representation of a gasification system, in accordance with one embodiment of the present disclosure.
DETAILED DESCRIPTION
The present disclosure will now be described with reference to the accompanying drawing which does not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the

embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The description hereinafter, of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
The present disclosure envisages a two-stage and direct gasification system for optimization of the gasification process. The gasification system 300 of the present disclosure is illustrated in FIGURE 1. Referring to FIGURE 1, the gasification system 300 includes a combustion chamber assembly 400 and a gasification chamber assembly 500. The combustion chamber assembly 400 includes a combustion chamber 130, a firing device 140 and a distribution plate 110. The combustion chamber 130 has a combustion bed 120, typically a fluidized bed or a circulating bed. The gasification chamber assembly 500 includes a gasification chamber 150 and a distributor plate 155. The gasification

chamber 150 includes an inlet 160 for facilitating feeding of a second portion of the feedstock inside the gasification chamber 150.
The combustion chamber 130 is interfaced with a gasification chamber 150. A first portion of the feedstock, typically coal or biomass, is fired in the combustion chamber 130 in the presence of air/oxygen and steam. Typically, depending upon the calorific value of the feedstock, about 0 - 15 % of the feedstock and ash from gasification chamber / cyclone separator, is fed in the combustion chamber 130. The feedstock is combusted by firing device 140 provided in the combustion chamber 130. The combustion chamber 130 comprises the combustion bed 120 and the distribution plate 110 adapted to carry out combustion under atmospheric pressure and/or a suitable high pressure condition. The combustion chamber 130 is operated at a temperature between 800 - 1050 °C. The distribution plate 110 is provided for supplying an even flow of air/oxygen and steam 100 in the combustion chamber 130. Ash generated in the combustion chamber 130 is discharged through an ash discharge device 190 provided at the operative bottom of the combustion chamber 130. The ash discharge device 190 comprises an ash cooler (not shown) and a lock hopper (not shown).
The flue gases from the combustion chamber 130 are conveyed to the gasification chamber 150 near the operative bottom of the gasification chamber 150 through the distribution plate 155. The gasification chamber 150 comprises a gasification bed and is adapted to gasify a second portion, which is about 85 -100 % of the feedstock. Typically, the gasification bed is a fluidized bed or a circulating bed. The second portion of the feedstock is fed at the inlet 160

provided near the operative top of the gasification chamber 150. Additionally, an inlet 151 is provided to admit air/oxygen and steam into the gasification chamber 150 through the distribution plate 155. The inlet 151 is provided at the operative bottom of the gasification chamber 150. In the gasification chamber 150, oxygen from the flue gases is utilized in burning the feedstock and the heat converts the feedstock to syngas (synthesis gas) by gasification reactions. The gasification chamber 150 is operated at a temperature between 800 - 1050 °C under atmospheric pressure and/or a suitable high pressure condition.
The ash generated in the gasification chamber 150 is discharged via an opening near the operative bottom of the gasification chamber 150 and recycled via supply line 185 to the combustion chamber 130 for further combustion of unburnt particles. The syngas so generated is collected in the operative top-portion of the gasification chamber 150 and there from conveyed to a cyclone separator 170. The cyclone separator 170 separates any ash carried over with the syngas. This ash is discharged at the operative bottom of the cyclone separator 170 and recycled via a supply line 180 to the combustion chamber 130. The supply lines 185 and 180 adapted to convey ash from the gasification chamber 150 and the cyclone separator 170 to the combustion chamber 130 form a loop seal arrangement thereof.
The combustion chamber 130 is maintained at a higher pressure as compared to the gasification chamber 150 and the cyclone separator 170. The loop seal arrangement comprising the supply lines 180 and 185, therefore, is adapted to prevent any back flow of flue gas through the ash discharge device. The loop seal arrangement is connected to the combustion chamber 130 at a location

above the first distribution plate 110. The cleaned syngas from the cyclone separator 170 is discharged via a syngas discharge outlet provided at the operative top of the cyclone separator 170. The cleaned syngas from the cyclone separator 170 is then conveyed to a processing device 200 mainly comprising cooling device (not shown) and/or cleaning device (not shown). The cooling device is adapted to cool the syngas generated in the gasification chamber. The cleaning device is adapted to clean the syngas generated in the gasification chamber.
TECHNICAL ADVANCEMENTS AND ECONOMICAL SIGNIFICANCE
The technical advancements offered by the system of the present disclosure which add to the economic significance of the disclosure include the realization of:
• a gasification system that provides complete gasification of feedstock;
• a gasification system which is suitable for high ash containing feedstock;
• a gasification system that is comparatively more efficient;
• a gasification system that is simple in construction;
• a gasification system that provides separation of combustion and gasification stages for optimization of each process; and

• a gasification system that is easy to operate.
Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression "at least" or "at least one" suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.

We Claim:
1. A gasification system comprising:
• a combustion chamber assembly comprising,
• a combustion chamber having a combustion bed;
• a firing device provided in said combustion chamber and adapted to facilitate combustion of a first portion of a feedstock and ash from gasification chamber / cyclone separator, fed inside said combustion chamber;
• a distributor plate disposed inside said combustion chamber and adapted to facilitate supply of air/oxygen and steam to said combustion chamber; and
• a gasification chamber assembly connected to said combustion
chamber assembly for facilitating flow of flue gas generated by
combustion of said first portion of said feedstock from said
combustion chamber to said gasification chamber assembly, said
gasification chamber assembly comprising,
• a gasification chamber connected to said combustion chamber for
facilitating flow of said flue gas generated by combustion of said
first portion of said feedstock from said combustion chamber to
said gasification chamber, said gasification chamber having,
o a gasification bed; and
o an inlet for facilitating feeding of a second portion of said
feedstock inside said gasification chamber; o at least one inlet for admitting additional air/oxygen and
steam in to said gasification chamber; and

• a distributor plate disposed inside said gasification chamber, wherein said gasification chamber assembly is adapted to convert said feedstock to syngas by utilizing said flue gases generated by combustion of said first portion of said feedstock and ash from gasification chamber / cyclone separator from said combustion chamber.
2. The gasification system as claimed in claim 1, wherein said combustion chamber assembly further comprises an ash discharge device connected at the operative bottom of said combustion chamber for discharging ash contained in said combustion chamber.
3. The gasification system as claimed in claim 1, wherein said combustion chamber assembly is maintained at a higher pressure as compared to said gasification chamber assembly.
4. The gasification system as claimed in claim 1, wherein said first portion of said feedstock is in the range of 0 to 15 % of said feedstock depending on calorific value of said feedstock and ash from gasification chamber / cyclone separator.
5. The gasification system as claimed in claim 1, wherein said combustion chamber is operated at a temperature in the range of 800 to 1050 °C.
6. The gasification system as claimed in claim 1, wherein said second portion of said feedstock is in the range of 85 to 100 % of said feedstock depending on calorific value of said feedstock.

7. The gasification system as claimed in claim 1, wherein said gasification chamber is operated at a temperature in the range of 800 to 1050 °C.
8. The gasification system as claimed in claim 1, wherein said feedstock is coal.
9. The gasification system as claimed in claim 1, wherein said feedstock is bi.omass.
10.The gasification system as claimed in claim 1, further comprising a cyclone separator connected after said gasification chamber assembly for separating ash carried over by said syngas.
11. The gasification system as claimed in claim 10, further comprising a plurality of supply lines for collecting ash from said gasification chamber and said cyclone separator to said combustion chamber, wherein each of said plurality of supply lines prevents backflow of said flue has from said combustion chamber to said gasification chamber/ cyclone separator.
12.The gasification system as claimed in claim 1, further comprising a cooling device for cooling said syngas generated in said gasification chamber.
13.The gasification system as claimed in claim 1, further comprising a cleaning device for cleaning said syngas generated in said gasification chamber.
14.The gasification system as claimed in claim 1, wherein said combustion bed is selected from the group consisting of fluidized bed and circulating bed.

15.The gasification system as claimed in claim 1, wherein said gasification bed is selected from the group consisting of fluidized bed and circulating bed.