FORM-2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
PROVISIONAL
Secification
[See Section 10 and rule 13]
1 Title of the Invention.
"UPDRAFT GASIFICATION TAR CRACKING SYSTEM"
2 Applicant (s)
1 Applicant Radhe Renewable Energy Development Pvt. Ltd
Nationality India
Address Plot-2621/22, Gate-1, Road-D/2, Lodhika GIDC, Kalawad Road, Po. Metoda, Rajkot- 360 021, Gujarat, India.
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF INVENTION
The invention relates to Updraft gasifier. Present invention also relates to tar cracking system. This invention further relates to preheating of tar in tar tank while continuously stirring. This invention also relates to generation of small droplets with the help of firing nozzle to increase surface area for combustion. Present invention further relates to complete utilization of energy from coal, biomass or waste by recycling tar into updraft gasifier system.
BACKGROUND OF INVENTION
Coal / Biomass Gasification is a process of thermo chemical process which converts Coal/ loose Biomass solid fuels to into Gaseous fuel. Thus gasified gases fuel will be transported to user point and will be burnt efficiently compare to solid fuels.
The process is known as Thermo Chemical Conversion. The equipment used for said process is Gasifiers. These gasifiers are extensively used for biomass/coal gasification. Biomass gasification technology is using biomass waste and coal as feeding material for power generation, industrial heating and for providing supply of gas. Due to said technology's flexibility and high product quality, researches are growing fast in this field.
Various gasifiers like Updraft, Downdraft, Cross draft, Fluidized bed and fixed bed are used for biomass gasification process. Common disadvantage of these all gasifiers are amount of tar generation in small quantity or in large quantity. Tar is most hazardous, pollution genie and carcinogenic product. Therefore reduction in amount of tar generation is important in gasifiers.
Tar removal from the producer gas is done by mainly three processes:
• Catalytic cracking of tar.
• Thermal cracking of tar.
• Physical removal of tar.

(1) Catalytic cracking
Various natural minerals are used as catalysts in tar removal are along with others stone materials (dolomite, limestone), olivine, clay minerals and iron ore. Dolomite CaMg (C03)2 is generally used, cheap catalyst material which has a high conversion rate of tars (-95%). The disadvantage of said catalyst is quick erosion. Catalysts that have been used as crackers of tar are also used as char and metal catalysts, of which nickel based catalysts, are most favored. Char is formed in the gasification process which is cheap catalyst. In typical air gasification (750°C) system its conversion of percentage of tars is more than 95%.Nickel is also used as catalyst in tar cracking. But nickel is deactivated easily from effect of sulphur compound. So it is not useful for removing tar of sulphur products.
(2) Thermal cracking of tars
Thermal cracking of tars process occurs without a catalyst by handling gas in high temperatures above 90G°C. Higher amount of tar is decomposed above 1300°C. During thermal cracking process, tar is decomposed in synthesis gases and only low amount of methane is present.
(3) Physical removal of tar
The process is worked at lower temperatures compare to thermal and catalytic cracking, mainly using electrostatic precipitation, wet scrubbers, filters or cyclones. The tar is effectively removed by the wet scrubbers or electrostatic filters and these methods are more efficient method. The method is efficient especially for small tar particles in the aerosol form. In said method used filters are clogged easily so it is not much useful method for cleaning of tar. Another problem is also associated with that using cyclones the tar sticking to the surface of the cyclone causes problems. These techniques are mainly used for the removal of particles and inorganic compounds when cleaning the gas.

Biomass waste or coal to be gasified in gasifier is typically introduced from the top or bottom of the gasifier. An oxygen containing gas such as air is introduced to the thermal reactor to form combustion zone below the organic material which has temperature around 1000°C to 1200°C. The temperature generates heat which is required for gasification from combustion the residue of the gasification reaction. The hot gases from the combustion zone are forced upward through the mass of organic material by the introduced air. The heated air and gases cause destructive distillation of the organic material and the generation of hydrogen, carbon monoxide and other carbon containing gases including carbohydrate gases according to reactions such as the following:
CxHyOz+ 02= C + CO + C02+ Cx1-xnHy1-ynOz1-zn
Gaseous biomass tars can react under inert conditions (thermal cracking) or with generated fuel gas components such as H2, H20 and CO2 (gasification).Thermal tar cracking process required high temperature around 1200°C or higher depending on resident time which is important to use problem free fuel gas in gasifier. The rate of thermal cracking of different types of tar decreases in following series:
Biomass pyrolysis oils/tars >
Phenolic tar compounds (phenol, cresol and naphthol)
>
Coal based pyrolysis tars
>
Polycyclic aromatic tar compounds (anthracene, phenanthrene, naphthalene, benzene)
The gas phase components like H2, H2O and CO2 play an important role in cracking reactions in a biomass fuel gas (air, steam or oxygen gasification) or at elevated hydrogen pressures. Presences of H2O and/or CO2 increase the tar decomposition rate, whereas H2 reduces it. High hydrogen pressure and high temperature may be forced hydrogenation of aromatic ring in hydrogasification process which causes higher concentration of CH4 as well as tar decomposition.

An important feature considered in the design of a thermal gasification reactor is the provision for intimate contact of the newly introduced organic material with the hot air and gases from the combustion zone to promote efficient gasification and during same time provision for the efficient removal of tar from gasifier and it is recycled back to combustion zone.
Downdraft Gasification system has certain disadvantages compare to Updraft gasification system which are following:
• Require feed drying to low moisture content (< 20%).
• Syngas exiting reactor is at high temperature require secondary heat recovery system.
• 4-7% of carbon remains unconverted.
Updraft gasifier system:
It is also called as counter flow gasification, the updraft configuration is simplest form of gasifier; it is still used for coal gasification. From the top of the reactor, biomass or coal is fed, and a grate at the bottom of the reactor which is act as the reacting bed. Air or oxygen and/or steam are introduced below the grate and they are diffuse up through the bed of biomass and char. At the bottom of the bed complete combustion of char take place which liberate CO2 and H2O and this zone is known as combustion zone. The second reaction take place in reduction zone where these hot gases (1000°C to 1300°C or higher) pass through the bed above another zone of gasifier, where they are reduced to H2 and CO and cooled up to 750°C which is known as reduction zone has temperature around 700°C to 900°C. Continuing up the reactor, the reducing gases (H2 and CO) pyrolyse in the pyrolysis zone (temperature 400°C to 600°C ) descending dry biomass and finally dry the incoming wet biomass. leaving the reactor at a low temperature (200°C to 300°C) in drying zone.
Advantages:
• High amount of charcoal/biomass burn out.
• High efficiency of equipments.

• Gas exit at low temperature.
• Work with high amount of moisture content product also.
Disadvantages:
• It has high amount of tar generation so reduction of tar is important.
• Therefore the present invention is related to thermal tar cracking method in updraft gasification system.
The high amount of tar cracking is solved in present invention.
European Patent No.1577366 disclosed tar cracking by catalyst. But earlier as mentioned disadvantage of cataiytical method it is not quite efficient for cracking all type of tar components.
Further in U.S. Patent No. 4,614,523 (1986), Soares discloses a down flow gasifier for waste wood and bio- mass having downward directed air introduction nozzles and a reactor cooling jacket. The Soares system, however, is a complicated structure, the gas off take would be subject to clogging by deposition of tars and particulates carried by the product gaseous effluent when certain feed materials are employed, and many fine materials will restrict air flow through the bed.
Moreover, the system and method for thermal cracking of hydrocarbons comprising mass is disclosed in the PCT application No.PCT/NL2010/000109. Said system required specialized equipment for heating and cooling. It has very complex working process too. In this process material are transferred from one reactor to another batch wise only. So it is not economical and it is time consuming process too.
The present invention has less complex process compare to earlier inventions and efficient capacity of thermal tar cracking. This invention comprises the updraft gasification with tar cracking system. Said invention also comprises preheating process. Pre heating of tar has advantage that it liquefied the semi slug tar which is difficult to recycle compare to liquid tar and require less energy in transfer. Then said tar is

transferred to firing nozzle which forms small droplets of liquid tar which has larger surface area compare to liquid or solid so said droplets are easily combusted because these droplets require less energy compare to liquid and solid and it has direct contact with hot air. Said invention provides complete tar cracking.
OBJECTIVES OF INVENTION
Primary object of the present invention is to provide an updraft gasification tar cracking system, recycling the tar completely and reutilizing the energy from tar cracking process in the same system providing syngas or combustible gas as a gaseous fuel from biomass wastes or coals being useful for power generation and also used as fuel in industry.
Another objective of present invention is reduction in amount of tar generation from feeding material due to tar has hazardous and carcinogenic properties and it is big problem of gasifier technology.
Still another object of present invention is preventing clogging of pipes due to condensation of tar. In present invention pre heating method is used which liquefied the semisolid tar. So it decreases the chances of clogging of pipes.
Further object of present invention is cracking of tar for generation of further energy from tar for reduction of requirement of energy. If tar is not recycled than efficiency of gasifier is reduced because of wastage of higher energy valued tar without complete utilization of its energy.
Another object of present invention is to provide higher surface are for cracking by using firing nozzle which provide small droplets of liquid tar. These small droplets has higher surface area compare to liquid tar so efficient cracking of tar occur which is not present any earlier systems.

Further object of present invention is preventing coke deposition in engine or turbine which occur due to presence of tar and particulate in produced gas from gasifier. The present invention completely recycles the tar of gasifier.
Still another object of present invention is production of economic gasifier because presently proposed gasifier system utilizes complete energy from the feeding material and said system has not been connected with further equipments or materials which are used by catalytic cracking process and physical method process.
BREIF DESCRIPTION OF THE DRAWINGS
Fig. 1 is schematic diagram of updraft gasification tar cracking system.
Fig. 2 is a cross sectional view of combustion zone of gasifier indicated by section AA' shown in Figure 1.
DETAILED DESCRIPTION OF THE INVENTION
Besides of prior art inventions present invention is quite different. The present invention provides complete tar cracking without remaining tar in the updraft gasifier system. Present invention also relates to method of complete tar cracking in up draft gasifier and to an apparatus for carrying out the method. The preferred system for complete tar cracking is described herein after. Various aspects of apparatus of this disclosure are illustrated in Fig. 1 and 2.
The preferred system comprises different components where different reactions take place and these components are interconnected by different components and this embodiment is called as updraft gasification tar cracking system, wherein said different components are described as following:
• The reactor or gasifier (1) for combustion of biomass or coal and generation of hot producer gas (34).

• Tar firing nozzle (2) for producing small droplets of liquid tar (4).
• The tar tank (3) which is reservoir of the collected tar (4) which are transferred from cleaning system like wet ESP and scrubbing after cleaning.
Fig.l shows the reactor or gasifier (1) has facility of hopper system (5) at the top which comprises two parts, one part (6) is outside the reactor or gasifier and another part (7) is inside of the reactor or gasifier (1). The hopper system provides feeding material to the reactor (1). Sized biomass briquettes (60 mm to 90 mm) or sized coal (20 mm to 75 mm) is being used as feeding material. Said hopper system comprises one inlet (8) for transferring of the feeding material having lift bucket (9) for providing feeding material from ground to feeding inlet (8).
The air (10) and steam (11) are supplied from the bottom which is useful for the oxidation of the feeding material as well as tar (4).Said air and steam are introduced in gasifier by a pump (12) and said system comprises facility of the water seal (13) also.
Referring to Fig. 1, the reactor or gasifier is divided in to five separate zones according to which type of reaction is taking place inside the different zones. From top to bottom of gasifier, said zones are as following:
• Drying zone (14) (temperature 200°C to 300°C )
• Pyrolysis zone (15)(temperature 400°C to 600°C)
• Reduction zone (16)(temperature 700°C to 900°C)
• Combustion zone (17) (temperature 1100 °C to 1300°C) -
• Ash zone (18) which contain ash and/or grit after combustion
These all five zones are surrounded by inner shell (19) which is made up of MS steel plates with inner lining of fire bricks for insulation purpose. Water jacket (21) is between inner shell (19) and outer shell (20) made up of MS steel plates having thickness of 10 mm with inner lining of fire bricks having thickness of 10 mm. Gasifier comprises outlet (22) for hot producer gas (34) containing tar (4).Said gasifier (1) has facility of Hydraulic operated Rotary grate (23) for wet ash disposal.

Another component of said system is tar tank (3) in which tar (4) is collected after cleaning processes like wet ESP (electrostatic precipitation) and scrubbing process The tar tank (3) has facility for heating by means of thermic fluid (24) which is indirect heating method .The tar tank has facility of insulation layer (35) for preventing heat loss. The temperature inside the tar tank is maintained 125°C to 150°C. Said temperature liquefies the semisolid tar. The temperature inside of the tar tank (3) is measured by the thermocouples which are present on the top (25) and bottom (26) of the tar tank (3).Said tank comprises stirring facility for which any type of industrial stirrer (27) having speed of5-10 RPM can be used.
Referring to Fig.l and Fig.2, another component of present system is tar firing nozzle (2) which is connected with the tar tank (3) by tar pump (29) is useful for transferring of viscous tar liquid without producing turbulence and foaming. Gear or screw pump can be used as tar pump. Tar firing nozzle system comprises valve (30) and tar pusher (31) for cleaning of tar firing nozzle. Firing nozzle system is connected with the gasifier (1) by the main feeding hole (33) which supplies the tar droplets generated by firing nozzle (2) passing through the heating pad (32) to the combustion zone for cracking of tar. The heating pad (32) is provided for heating of tar and its droplets (4) passing through the main feeding hole (33) having diameter 2 mm to 5 mm.
The method of complete tar cracking in updraft gasification system is described hereinafter:
Feeding materials like biomass briquettes and sized coal are fed from inlet (8) and these feeding materials are subjected to drying, pyrolysis, reduction and oxidation on its downwards in the reactor or gasifier (1). In the present updraft gasification tar cracking system feeding materials are oxidized at 1100°C to 1200°C in the combustion zone (17) by the air and steam which are introducing from the bottom of gasifier by the pump (12). Steam (11) is generated from the water jacket due to temperature of combustion zone (17). The second reaction taking place at reduction zone (16) where carbon and carbon dioxide react with air and steam and said reaction generates Carbon monoxide and

hydrogen at 750°C to 800°C. The producer gas enters in third pyrolysis zone where methane and multi chain hydrocarbons (Tar vapor) generates at 500°C to 600°C further enter to drying zone where solid fuel get dried and finally hot producer gas (34) having Calorific value of 1000-1200 Kcal/m3 and temperature around 300°C with an average composition of CO: 20-25 %, H2: 15-20 %, CH4: 1-3 %, C02: 5-8%, moisture and Tar.
Said generated hot producer gas contains tar (4) which is separated from said hot producer gas by wet ESP (Electrostatic precipitation) and wet scrubbing. After cleaning of generated hot producer gas (34), it is used for power generation and other industrial application. Then said tar (4) is transferred into the tar tank (3) where preheating of said tar (4) at 125°C to 150° C with the help of thermic fluid (24) take place for 20-30 minutes in starting than later it continues heating which cause liquification of semisolid tar (4) during this time the tar tank (3) is continuously stirred by industrial stirrer having speed of 5-10 RPM. Then said preheated tar (4) is transferred by tar pump (29) to firing nozzle (2).Header of tar supply (28) shown in Fig.2 has diameter of 75 mm and main feeding hole (33) has diameter 2 mm to 5 mm. Said firing nozzle (2) generates small droplets of tar by means of pressure generated by tar pump (29) (Nominal about 1 kg/cm2 to 1.5 kg/cm2) at the tip of the firing nozzle and these droplets has higher surface area compare to liquid tar. These small droplets are transferred through main feeding hole (33) to combustion zone (17) of reactor or gasifier (1) passing through heating pad (32). Temperature (1100°C to 1200°C) of the combustion zone (17) cracks these tar droplets along with combustion of the feeding material which generates gases and they are further used as energy source. Said cracking process supplies extra energy to gasifier system.
Therefore the present system completely utilize the energy of feeding material without forming hazardous by product like tar by reutilizing tar in the combustion zone of gasifier causing nearly 100% energy conversion in the same system.

We claim:
1. An updraft gasification tar cracking system comprising following components:
- Gasifier or reactor (1);
- Tar firing nozzle (2) for generation of small droplets of tar (4);
- Tar tank (3);
- Hopper system (5) for supplying feeding material to gasifier;
- Inlet (8) for supplying feeding material to hopper system (5);
- Lift bucket (9) for supplying feeding material from ground to inlet (8);
- Pump (12) for introduction of air (10) and steam (11) to the bottom of said gasifier (1):
- Inner (19) and outer (20) shell;
- Water j acket (21) between two shells;
- Outlet (22) for hot producer gas (34);
- Hydraulic operated rotary grate (23) for wet ash disposal;
- The main feeding hole (33) passing through heating pad (32) for supplying of liquid tar droplets from firing nozzle (2) to combustion zone (17) of gasifier;
- Header (28) for tar supply to main feeding bole (33);
- Tar pump (29) for transferring of liquid tar (4) from tar tank (3) to firing nozzle (2);
- Thermocouples at the top (25) and bottom (26) of tar tank (3) for checking temperature of tar tank (3);
- Stirrer (27) used for continuous stirring of tar tank (3);
- Insulation layer (35) of tar tank for preventing heat loss of tar tank (3);and
- Thermic fluid (24) for heating of tar tank (3).
2. The feeding materials used in said system are briquette (60 mm to 90 mm) and/or
sized coal (20 mm to 75 mm).

3. The hopper system (5) as claimed in claim 1, wherein said hopper system comprising two parts, one is outside (6) of reactor or gasifier and another (7) is inside of it.
4. The stirrer (27) as claimed in claim 1, wherein the said stirrer is any type of industrial stirrer having speed of 5 to 10 RPM
5. The tar pump (29) as claimed in claim 1, wherein the said tar pump is gear pump or screw pump.
6. The tar pump as claimed in claim 5, wherein the said tar pump generates pressure of 1 to 1.5 kg/cm2 atthe tip of firing nozzle for generation oftar droplets.
7. The main feeding hole (33) as claimed in claim 1, wherein the said hole has diameter 2 mm to 5 mm.
8. The header (28) for tar supply as claimed in claim 1, wherein said header has diameter of 75 mm.
9. The shells as claimed in claim 1, wherein the shells are made up of MS steel plates thickness 10 mm with inner lining of fire bricks' thickness 10 mm.
10. The method oftar cracking in updraft gasification tar cracking system comprising:

- Feeding of biomass briquettes and sized coal by feeding inlet (8) to gasifier passing through hopper system (5);
- Passing the feeding material in the downwards direction through Drying zone (14), Pyrolysis zone (15), Reduction zone (16) of gasifier for Drying, pyrolysis and reduction of feeding material in the respective zones;
- Supplying of air and steam to combustion zone (17) from bottom of gasifier with the help of pump for the combustion of the feeding material

and oxidation of feeding material at 1100°C to 1200°C in combustion zone (17) generates hot producer gas (34) along with tar which releases in upward direction and passes through reduction zone (16), pyrolysis zone (15) and drying zone (14) leaving the gasifier from outlet (22) having 300°C temperature;
- Cleaning of hot producer gas (34) containing tar by cleaning system wet ESP and scrubbing and separation of the tar from the hot producer gas;
- Transferring the tar (4) to the tar tank (3);
- Pre heating of tar which is in semisolid form converted into liquid form due to continuous stirring by industrial stirrer (27) at temperature 125°C to 150°C;
- Transferring of liquefied tar from tar tank (3) to firing nozzle (2) by tar pump (29);
- Generating of small droplets of liquid tar with the help of firing nozzle (2) by means of pressure nominal about 1-1.5 kg/cm2 at the tip of the nozzle;
- Transferring of said droplets to combustion zone (17) through main feeding hole passing through heating pad;
- Cracking of these droplets due to the temperature of combustion zone (17) along with feeding material and production of energy from the tar ; and
- Removing of ash from ash zone (18) after completion of process by hydraulic operated rotary grate (23).