Title of Invention

"A PROCESS FOR THE PRODUCTION OF BRIQUETTES LOW ASH USING CALCINED PETROLEUM COKE "

Abstract The present invention relates to a process for the production of briquette of low ash using calcined petroleum coke. The main usage of the invention is to provide a process for the production of low ash, low phosphorus alternative fuel of moulded shape, hard, water resistant having chemical composition such that the product can be safely used in place of by-product/ bee-hive coke for industrial and/or metallurgical purposes. The process developed for producing low ash, tailor made fuel using calcined petroleum coke will augment the production of briquette fuel of low ash, low phosphorus content, which can substitute the scarce low ash metallurgical/industrial
Full Text The present invention relates to a process -for the production of low ash fuel using calcined petroleum coke.
The main usage of the invention is to provide a process -for the production of 1 low ash, law phosphorus alternative fuel of moulded shape, hard, water resistant having chemical composition such that the product can be safely used in place o-f by-product/ bee-hive coke for industrial and/or metallurgical purposes.
Petroleum coke is produced during refining of crude petroleum oil. After calcination, petroleum coke gives an excellent quality of carbonaceous material having very low ash, low volatile matter, low phosphorus and high fixed carbon content. The calcined petroleum coke has a very limited utility and at present to some extent is used in Electrode industry. It has no use in industria1/meta1lurgical purposes due to its physical and chemical properties which have made it unsuitable to withstand the burden in the furnace. Most of the oil refineries in the country have a very good stock of calcined petroleum coke. In recent years the demand for low ash meta1lurgica1/industria1 coke has increased manifold and the demand is rapidly increasing with the setting up of mini steel plants and foundries for production of high grade steel and casting materials of International Standard.
The process developed for producing low ash, tailor made fuel using calcined petroleum coke will augment the production of briquette fuel of low ash, low phosphorus content, which can substitute the scarce low ash metallurgical/industrial

in the low shaft furnaces, cupolas, etc. to produce high grace steel and casting material. Low fuel no only helps to produce good quality product but also helps to increase the productivity which is bound to help the industry in a competitive market.
Metallurgical/industria1 coke is produced by high temperature carbonisation of coal either in nan-recover. type bee-hive overs or byproduct recovery type coke ovens. For producing low ash, low phosphorus metal 1urgical/industrial coke, coal of low ash low phosphorus content has to be carbonise". But in India, the availability of low ash, low phosphorus content coking coal is highly scarce which has compelled the Iron & Steel Industry to import low ash low phosphorus metallurgical coke for production of high grade steel and casting materials. There are processes developed for producing briquette fuel using coal/coke breeze and processed coal tar as binder which can substitute the conventional Coke used in metallurgica1/industrial purposes. In Indian Patent No. 129108 a process has been describe for production o- weather resistant, hard, skokeless moulded fuels for industrial/ metallurgical uses using coke breeze/char etc. All the processes mentioned above are for producing bric-etted fuel which can substitute the conventional industrial/ metallurgical coke. But like conventional coke the briquette fuel made from coke • breeze is also high ash and moderately high phosphorus content. Such type of product is not suitable for producing high grade low phos iron and steel. Present days' demand of the iron and steel industry is for low ash, low phosphorus meta1lurgical/industria1 coke to produce high grade

Steel and foundry materials in an economic way to make the product competitive in the market. Prior to the present invention no process was developed and or processed tar for production of fuel of low ash, low phosphorus content which can substitute the scarce low ash metallurgical/industrial coke. The present invention will eliminate the shortage of availability of low ash, low phosphorus metallurgical coke by briquetted fuel prepared by calcined petroleum coke which is plenty available in the country.
The main object of the present invention is to provide a process for the production of low ash fuel using calcined petroleum coke which obviates drawbacks as detailed above.
Another object of the present invention is to utilize the briquetted fuel for the production of special grade iron and steel as the content of ash and phosphorus in the product is much below than those present in by-product/bee-hive coke.
Still another object of the present invention is to produce a product of uniform size and shape which permits full utilization of the product and provides better air permeability through the bed.
Accordingly the present invention provides a process for the production of briquettes of low ash using calcined petroleum coke which comprises; crushing and screening of calcined petroleum coke below 3 mm size, mixing the crushed and screened coke materials to achieve a bulk density in the range of 760 to 800 kg/m3 , mixing 10-100% of the resultant calcined petroleum coke with 0 to 50% coke breeze.
presoaking the mix so obtained with 5-10% water, mixing with binder in the range of 6 to 7% followed by kneading in presence of steam, briquetting by known methods and curing of the raw briquettes in a furnace at a temperature in the range of 250 to 300°C for a period in the range of 2.5 to 5.5 hours, in a controlled oxidizing atmosphere to obtain briquette of low ash.
The product, comprising of low phosphorus alternate fuel of moulded shape, hard, water resistant, can be safely used in place of by-product/bee-hive coke for industrial and/or metallurgical purposes.
The product can be suitably shaped and sized as per requirements of the Ferro-chrome, Ferro-Silicon, Ferro-manganese and allied industries. Binders like Asphalt of 80/100 grade, and processed low temperature tar are used which are readily available in the market and thus minimizes the cost towards the preparation of binder. The process does not require any carbonization step to make the product smokeless, hard and water resistant which makes the process, comparatively less energy incentive. a)The calcined petroleum coke obtained from oil refiner is screened at 3mm. The plus 3 mm of calcined petroleum coke obtained after screening is crushed to below 3 mm and then mixed with minus 3 mm size fraction previously obtained by screening to achieve the bulk density range of 760-800 kg/m3.
b) The use of calcined petroleum coke at the range of 10-50% by weight, mixed with coke breeze ( x3 mm) gives higher strength in terms of point crushing strength and micum
indices. The ash content of the product is also increased to that extent which will be helpful to maintain the slag viscosity in the -furnace hearth.
(c) The calcined petroleum coke with or without breeze is then pre-soaked with 5-107. water by weight of dry solids. Then it is mixed with Asphalt of 80/100 grade used as binder. The proportion o-f solids: binder is maintained at 93:7 by weight of dry solids. The binder may be asphalt of 83/100 grade having softening point of 45-52°C or a cut fraction above 300°C having S.P. 45-52°C of coal tar obtained from low temperature/medium temperature carbonisation of coal.
(d) The mixture is then thoroughly mixed and kneaded in the
kneader unit in presence of live steam at a gauge pressure
2
of 6.0 kg/cm2 - 8.3 kg/cm where the temperature of the
mixture goes upto 70-90 C.
( e) The hot mixture from the kneader is then fee to a twin paddle mixer to cool down the temperature of mixture at 50-60°C.
(f) The mixture from the mixer as stated in (e) is then fed to twin roll briquetting press through a screw feeder/pan
feeder. The mixture is briquetted by twin roll press at a

pressure of 200-300 kg/cm . The green briquettes obtained
from the rolls are of shape and of weight between 25 gm to 380 gm depending on the dimension of the briquettes, (g) The green briquettes, are cured in the furnace in batches. The heating of the furnace and the control of the
temperature at desired level is done by generating hot -flue gas by combustion or coal m a control lea oxidising atmosphere. The temperature of curing bed is raised by introducing hot flue gas to the briquettes placed in layers in a controlled condition. The final temperature of curing bed is raised to 250-300°C and the temperature is maintained in that range for about 2.5 - 5.5 hours depending on dimension of the briquettes.
(h) The cured briquettes are then taken out of the furnace and cooled in the atmosphere.
The following examples are given by way of illustration
of the present invention and should not be construed to limit the
scope of the present invention.
EXAMPLE - I
Calcined petroleum coke (CPC) was initially screened on 3 mm screen and the oversize of CPC was crushed in Jaw crusher followed by double roll crusher using 3 mm screen so as to obtain the product passing 1007. through 3 mm. The screened and crushed CPC was mixed thoroughly and intimately. CPC (x3 mm) was then mixed with coke breeze (x 3 mm) in the ratio of 10:90 by weight. The mix was then pre-soaked with 10.07. water and then mixed with 7.07. asphalt of 80/100 grade by weight. The mix was then
conveyed to a kneader-cum-mixer where it was thoroughly kneaded

2 in presence o-f live steam at a pressure of 6 kg/cm . The
Hot kneaded material was then passed through a twin paddle type cooler mixer to cool the mix to a temperature of 55-60 C.
The cooled material was then continuouslyted into a twin roll
briquetting press through a screw -feeder and briuetted at 220-
240 kg/cm2 pressure. Finally raw briquettes were cured in a
furnace at a temperature of 250 + 100C for Z hours by generating hot flue gas under controlled conditions.
PROPERTIES OF CURED BRIQUETTES
(i) Wt/briquette, gm : 72.9

(ii) Bulk density, kg/m : 672
(iii)Point crushing strength, kg : 299
(iv ) Micum Index
M40 : 95.0
Ml0 : 5.0
(v) Porosity, 7. : 40.1
( vi ) Proximate analysis ,
M : 1 .7
Ash : 19.7
V. M. : 5.1
F.C. : 73.5
(vii) C.V, Kcal/kg : 5385
(viii) Reactivity towards Co2 • 142
(ix) Phosphorus, 7. : (3.035
(x) Sulphur, '/. : 0.72
(xi) Nitrogen, 7. : 0.95
(xii) Carbon, X : 75.70
(xiii) Hydrogen, 7. : 0.80
EXAMPLE - II
Calcined petroleum coke ( CPC ) was initially screened on 3 mm screen and the oversize o-f CPC was crushed in jaw. crusher followed by Double roll crusher using 3 mm screen so as to obtain the product passing 1007. through 3 mm. The screened and crushed CPC was mixed thoroughly and intimately. CPC ( x 3 mm) was then mixed with coke breeze (x 3 mm) in the ratio o-f 20:80 by weight. The mix was then pre-soaked with 10.07. water and then mixed with 7.07. asphalt of 80/100 grade by weight. The mix was then
conveyed to a kneader-cum-mixer where it was thoroughly kneaded

in presence of live steam at a pressure of 6 kg/cm2. The hot
kneaded material was then passed through a twin paddle type cooler mixer to cool the mix to a temp, of 55-60 C. The cooled material was then continuously fed into a twin roll briquetting press through a screw feeder and briquetted at 220-2^2 kg/cm pressure. Finally raw briquettes were cured in a furnaze at a temp, o-f 250 + 10°C for 3 hours by generating hot flue gas under controlled conditions.
PROPERTIES OF CURED BRIQUETTES
(i) Wt/briquette, gm : 74.1
(ii) Bulk density, kg/m : 672
(iii)Point crushing strength, kg : 323 (iv) Micum Index
M40 : 92.5
Mi0 : 7.5
(v) Porosity, 7. : 38. 0
i ) Prox imate ana 1 ysis ,
N : 1 .6
Ash : 18.5
V. M. : 4.5
F.C. : 75.4
(vii) C.V, Kcal/kg : 5525
(viii) Reactivity towards Co2 : 146
(ix) Phosphorus, '/. : 0.037
(x) Sulphur, %. : 0.75
(xi) Nitrogen, % : 1.12
(xii) Carbon, 7. : 75.93
(xiii) Hydrogen, % : 1.01
EXAMPLE - III
Calcined petroleum coke (CPC) was initially screened on 3 mm screen and the oversize of CPC was crushed in jaw crusher Followed by Double roll crusher using 3 mm screen so as to obtain the product passing 1007. through 3 mm. The screened and crushed CPC was mixed thoroughly and intimately. CPC ( x 3 mm) was then mixed with coke breeze (x 3 mm) in the ratio of 30:70 by weight. The mix was then pre-soaked with 10.07. water and then mixed with 7.07. asphalt of 80/100 grade by weight. The mix was then
conveyed to a kneader-cum-mixer where it was thoroughly kneaded
in presence of live steam at a pressure of 6 kg/cm . The hot
kneaded material was then passed through a twin paddle type cooler mixer to cool the mix, to a temp, of 55-60 C. The coaled
material was then continuously fed into a twin roll briquetting
2 press through ,.a. screw feeder .and briquetted at 220-240 kg/cm
pressure. Finally raw briquettes were cured in a -furnace at a
temp. OF 250 ;+_ 100C for 3 hours by generating hot flue gas under controlled conditions.
PROPERTIES OF CURED BRIQUETTES
(i) Wt/briquette, gm : 77.0
(ii) Bulk density, kg/m ; 640
(iii)Point crushing strength, kg : 329
(iv) Micum Index
M40 : 90.0
M10 : 10.0
(v) Porosity, 7. : 29.9
(vi) Prox imate ana 1 ysis , %
M -.1.3
Ash : 15.4
V. M. : 4.5
F.C. : 78.8
(vii) C.V, Kcal/kg : 5895
(viii) Reactivity towards Co2 : 154
(ix) Phosphorus, 7. : 0.026
( (xi) Nitrogen, 7. : 0.94
(xii) Carbon, 7. : 79.79
(xiii) Hydrogen, 7. : 1.08
EXAMPLE - VI
Calcined petroleum coke (CPC) was initially screened on 3 mm screen and the oversize of CPC was crushed in jaw crusher followed by Double roll crusher using 3 mm screen so as to obtain
the product passing 1007. through 3 mm. The screened and crushed CPC was mixed thoroughly and intimately. CF'C ( x 3 mm) was then mixed with coke breeze (x 3 mm) in the ratio o-f 40:60 by weight. The mix was then pre-soaked with 10.07. water and then mixed with 7.37. asphalt of 80/100 grade by weight. The mix was then
conveyed to a kneader-cum-mixer where it was thoroughly kneaded
in presence of live steam at a pressure of 6 kg/cm2. The hot
kneaded material was then passed through a twin paddle type cooler mixer to cool the mix to a temp, of 55-60°C. The cooled material was then continuously fed into a twin roll briquetting press through a screw feeder and briquetted at 220-240 kg/cm pressure. Finally raw briquettes were cured in a furnace at a temp, of 250 + 10 C for 3 hours by generating hot flue gas under controlled conditions.
PROPERTIES OF CURED BRIQUETTES
(i) Wt/briquette, gm : 80.0
(ii) Bulk density, kg/m3 : 672
(iii)Point crushing strength, kg : 385
( iv ) Micum Index
M40 :91.2
Ml0 :8.8
(v) Porosity, '/. :31.6
( vi ) Prox imate analysis '/.
M : 0.6
Ash : 14.4
V. M. : 4.5
F. C. : 80.5
(vii) C.v, Kcal/kg : 6710
(viii) Reactivity towards Co2 : 156
(ix) Phosphorus, % : 0.017
(x) Sulphur, 7. : 0.75
(xi) Nitrogen, 7. : 0.68
(xii) Carbon, 7. : 81.49
(xiii) Hydrogen, 7. : 0.80
EXAMPLE - V
Calcined petroleum coke (CPC) was initially screened on 3 mm screen and the oversize of CPC was crushed in ; aw crusher followed by Double roll crusher using 3 mm screen so to obtain the product passing 1007. through 3 mm. The screened and crushed CPC was mixed thoroughly and intimately. CPC ( x 3) was then mixed with coke breeze (x 3 mm) in the ratio of 50:50 by weight. The mix was then pre-soaked with 10.07. water mixed with 7.07. asphalt of 80/100 grade by weight. The was then conveyed to a kneader—cum-mixer where it was kneaded in presence of live steam at a pressure of 6 kg/cm2. The hot kneaded material was then passed through a twin saddle type cooler mixer to cool the mix to a temp, of 55-60 C. The Cooled material was then continuously fed into a twin roll 3riquetting press through a screw feeder and briquetted at 220-240 kg/cm pressure. Finally raw briquettes were cured in a furnace at a temp, of 250 + 10 C for 3 hours by generating hot flue gas under controlled conditions.

PROPERTIES OF CURED BRIQUETTES
(i) Wt/briquette, gm : 77.7
(ii) Bulk density, kg/m3 : 688
(iii)Point crushing strength, kg : 425
(iv) Micum Index
M40 : 92.5
M10 : 7.5
(v) Porosity, 7. : 37.0
( v i ) Prox imate ana 1 ysis , %_
M : 1 . 1
Ash : 12.3
V. M. : 4.8
F.C. : 81.8
(vii) C.V, Kcal/kg : 6505
(viii) Reactivity towards Co2 : 138
(ix) Phosphorus, % : 0.010
(x) Sulphur, 7. : 0.86
(xi) Nitrogen, 7. : 0.80
(xii) Carbon, 7. : 83.08
(xiii) Hydrogen., 7. : 1.03
EXAMPLE - VI
Calcined petroleum coke (CPC) was initially screened on
3 mm screen and the oversize of CPC was crushed in Jaw Crusher
followed by double roll crusher using 3 mm screen so as to obtain
the product passing 1B07. through 3 mm. The screened and crushed
CPC was mixed thoroughly and intimately. The mix was then pre-
soaked with 107. water and then mixed with 7.07. asphalt of 80/100
grade by weight. The mix was then conveyed to a kneader-cum-
mixer where it was thoroughly kneaded material was the- passed through a twin paddle type cooler mixer to cool the mix to a temperature of 55-60°. The cooled material was then continuously
fed into a twin roll briquetting press through a screw feeder and

briquetted at 220-240 kg/cm2 pressure. Finally raw briquettes
were cured in a furnace at a temperature of 250 +. 10°C for 3 hours by generating hot flue gas under controlled conditions. The main advantages of the present invention are —
1. The process is simple and less expensive. The process
consists of calcined petroleum coke either as such or
by weight of dry solids, mixing with organic binder in
presence of live steam and then briquetted by twin roll
press at a pressure of 200-300 kg/cm2. The green
briquettes are then cured in a furnace at a temperature
of 250-300°C for a period of 2.5 - 5.5 hours.
2. The product obtained from the process is hard, shaped
and sized, smokeless, water and weather resistant fuel
from calcined . petroleum coke produced in oil refineries. The product obtained by uti1ising cent per cent calcined petroleum coke is of very low ash, low phosphorus content and can be suitably shaped and sized as per requirement in the Ferro-Chrome, Ferro-Silicon, Ferro-manganese and allied industries.
3. The process uses Asphalt (80/100 grade) as binder which
is readily available in the market and thus minimises
the cost towards binder preparations.

The process is relatively cheap since a lower percentage of binder is used and the crushing is required only -for a -fraction o-f calcined petroleum coke and coke breeze.
The process does not require any carbonisation step to make the product smokeless.
The process is relatively less expensive for the production of low ash, low phosphorus, high calorific value content product to be used as a fuel for industrial/metal lurgica1 purposes in place of conventional coke in the hearth. Capital investment required to set up a plant for a 40 tpd capacity will well remain within the limit marked-for Small Scale Industrial Sector.





We Claim:
1. A process for the production of briquettes of low ash using calcined petroleum
coke which comprises; crushing and screening of calcined petroleum coke below
3 mm size, mixing the crushed and screened coke materials to achieve a bulk
density in the range of 760 to 800 kg/m3 , mixing 10-100% of the resultant
calcined petroleum coke with 0 to 50% coke breeze, presoaking the mix so
obtained with 5-10% water, mixing with binder in the range of 6 to 7% followed
by kneading in presence of steam, briquetting by known methods and curing of
the raw briquettes in a furnace at a temperature in the range of 250 to 300°C for a
period in the range of 2.5 to 5.5 hours, in a controlled oxidizing atmosphere to
obtain briquette of low ash.
2. A process as claimed in claim 1, wherein Asphalt or processed low temperature
tar is used as binder.
3. A process for the production of briquette of low ash using calcined petroleum
coke substantially as herein described with reference to the examples
accompanying this specification.

Documents:

1311-del-1999-abstract.pdf

1311-del-1999-claims.pdf

1311-del-1999-correspondence-others.pdf

1311-del-1999-correspondence-po.pdf

1311-del-1999-description (complete).pdf

1311-del-1999-form-1.pdf

1311-del-1999-form-19.pdf

1311-del-1999-form-2.pdf

1311-del-1999-form-3.pdf


Patent Number 212669
Indian Patent Application Number 1311/DEL/1999
PG Journal Number 51/2007
Publication Date 21-Dec-2007
Grant Date 10-Dec-2007
Date of Filing 30-Sep-1999
Name of Patentee COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH
Applicant Address RAFI MARG, NEW DELHI-110001, INDIA.
Inventors:
# Inventor's Name Inventor's Address
1 PARAS NATH SINHA CENTRAL FUEL RESEARCH INSTITUTE, P.O. F.R.I.-828108, DISTRICT-DHANBAD, BIHAR, INDIA.
2 PARTHA SEN GUPTA CENTRAL FUEL RESEARCH INSTITUTE, P.O. F.R.I.-828108, DISTRICT-DHANBAD, BIHAR, INDIA.
3 KALI SHANKAR BHATTACHARJEE CENTRAL FUEL RESEARCH INSTITUTE, P.O. F.R.I.-828108, DISTRICT-DHANBAD, BIHAR, INDIA.
PCT International Classification Number C10L 5/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA