SDM COLLEGE OF ENGINEERING & TECHNOLOGY

Department of Chemical Engineering

Analysis & Comparison of cheaper binder for coal fines

Under The Guidance Of: Kiran Kumar Rathod

Name Of Students U.S.N

Abhishek 2sd10ch001

Rahul Patel 2sd10ch014

Priyanka Jain 2sd10ch015

Saurav Kumar 2sd10ch018

Introduction•India has vast coal reserves & ranked 5th in coal rich. countries.

•Although we are one of the top 5 leading producer of coal but we also lag behind by being in top most countries importing coals.

•185 billions tons of coal reserves are present in different regions of country.

•Coal reserves in India are mainly bituminous & sub-bituminous (not high grade coal) and thus not safe for environmental point of view.

•Coal in the process of mining, handling & exposure to weather is subjected to more or less disintegration & its known as slack. If this slack is wasted the loss ranges 5-50%.

Thus its essential for economical consideration.

Coal briquetting is a process which converts coking coal & slack into uniform usually hard and impact resistance agglomeration, making it useful with high calorific value for domestic & industrial purpose.

Coal import can be very expenses in some instances it accounts upto 70% of delivered cost of coal.

The first patent for the briquetting of coal fines dates back to the mid-1800s.

• Research and evaluate the binding and combustion properties of various binders for coal fines

• Develop a process to integrate binder and produce robust coal briquettes.

• Perform combustion testing to determine flame temperature, emissions profiles, efficiency, and chemical kinetics of the developed coal/binder product

Objective

Crucible swelling index (free swelling index) It is simplest test to evaluate whether a coal is suitable for

production of coke. After heating the coal, a small coke button remains in the

crucible. The cross sectional profile of this coke button compared to a

set of standardised profiles determines the Free Swelling Index.

Heating temperature:- 800°C

Before crushing After crushing into fines

Physical Properties of coal

Sulphur Content A known quantity of coal is heated with Eschka mixture (2 parts of

MgO and 1 part of anhydrous Na2CO3) Temp 800˚C. After burning amount of sulphur present in the mix is retained as

oxides and it is precipated as sulphates.The sulphate formed is precipitated as BaSO4 (by treating with BaCl2).

% of sulphur in coal = Where, weight of coal sample taken Weight of BaSO4 precipitate formed xy 1374 .0100 x y

Density It depends on the rank of the coal

and mineral impurity present.

Calorific value The calorific value determines in part the value of coal as a fuel for

combustion application using bomb calorimeter.

Bomb Calorimeter BOMB

Heat units in B. t. u. per pound of dry fuels

=14,600 C + 62,000(H - O/8) + 4000 S

Moisture Content

It is used to find the percentage of water present in coal. Typical range is 0.5 to 10% Moisture Increases heat loss, due to evaporation and superheating of

vapour Helps to a limit in binding fines. Temperature:- 105-110°C Heating time:- 1 hour Sample size:- 60 mesh Quantity of sample:- 1 gram air dried coal

% moisture in coal = {loss in wt. of coal X 100}

wt. of coal initially taken

Volatile Matter

Volatile matters are the methane, hydrocarbons, hydrogen and carbon monoxide, and incombustible gases like carbon dioxide found in coal.

Increases flame length, and helps in easier ignition of coal. crucible with lid. Quantity of sample:- 1 gram air dried coal Sample size:- 60 mesh Temperature:- 900-925°C Heating time:- 7-10 minutes % volatile matter =

{ loss in wt. of moisture free coal X 100}

wt. of moisture free coal taken

Fixed carbon Fixed carbon is the solid fuel left in the furnace after volatile

matter is distilled off. Fixed carbon gives a rough estimate of heating value of coal. % fixed carbon in coal = 100-(% moisture+% ash+% volatile

matter)

Ash content It represents the bulk mineral matter

after carbon, oxygen, sulfur and water

has been driven off during combustion. Heating temperature:- 750-800°C Heating time:- 1 hour

Result of Coal AnalysisProperties Values

FSI 7.2

Density 1306kg/m3

Sulphur 0.59%

Moisture 8.4%

Volatile content 7.62%

Fixed carbon 74.27%

Ash content 9.7%

Calorific Value 6150 kcal/kg

Note-percentage by weight

Characteristics of good binder1.Highly Coherence- By varying amount of binder & pressure.

2.Hardness and toughness-For better hardness high softening point binders to be used.

3.Density- Range for density 1.1 to 1.4 & density is increased by pressure.

4.Size and shape- Large cylindrical, hollow, polygonal, ball shaped briquette materials are good.

5.Burning qualities-• Readiness of ignition-Large briquette ignites readily than small

ones.• Kind of flame-should burn with clean, intense flame without

odour or smoke

Note-Organic briquette do not produce smoke.

6. Retention of shape-the binders must hold coal particles together until they are sufficient soften to cohere.

7.Weathering- Dense briquette will stand better for long exposure than porous.

8. Absorption-Should not absorb more than 3% of moisture.

9.Percentage of ash-It should be less & it depend on sum of contained in slack & binder used.

Note-Organic binders have less percentage of ash as

compared to inorganic.

Molasses Lignin Pitch

Dairy Sludge

Test for examination of binders Determination of percentage of binder

The percentage of binder is always calculated on the weight of coal.

Determination of coherence

By adding small amount of water and coal & performing strength tests on the coal.classified into following grades-

1. Very slight coherence 4. satisfactory

2. Slight coherence 5 .excellent, will stand rough handling

3. Coherence but not satisfactory 6. Stronger than necessary

20gms of coal mixed with binder & additive

Its then heated &

stirred well

throughly

It should be then

mechanically pressed.

Material required in coal briquetting are-Coal The slack taken as raw material should be thoroughly clean and should not

contain impurities. Its not uniform in size so for further process it is jaw crushed.

Additive In India coal contents high amount of sulphur & on combustion produces

CO2. It cause health & environmental problems. To overcome calcium carbonate is used to convert sulphur to sulphate.

Reactions Involved- CaCO3 CaO + CO2

S + O2 SO2

SO2 + 1/2O2 SO3

CaO + SO3 CaSO4

Binders It is used to bind fine particles physically. Various binder available are - Pitch • Dairy waste Lignosulphonate • Molasses

Methodology The method of manufacturing of coal briquettes are

1. Briquetting with binding material.

2. Briquetting without binding material.

Briquetting with binder

Compacted coal briquettes are taken out of moulds.

Make 8-10 mixtures of slack,

additive & binders

Heat untill the vapour forms & pour into moulds

Mechanical press is aplied for 2-3

min

Binder

Briquetted by

Mechanical Press

Additive=CaCO3

Coking Coal/ slack

0.3 mm particle size

Mixed & Milled

Dried

Briquettes

Processing with different binders

4 sample coal pieces

will be obtained for

analysis

Applying 2-5 tons of load

Mould Fabricated for mechanical Press

Advantages to coal briquetting Increase in heating value.

Resistance to weathering

Resistance to handling

Efficiency of fuel

Create less environmental as

compared to mineral coal.

Spontaneous combustion &

wastage coal can effectively be

controlled.

Our project give path to utilise

indigenous coal reserves without

polluting environment.

Techniques used to test briquettes

Strength

The compressive strength is a good indication that sufficient binder is being used, that the briquetting pressure is adequate and that post curing treatment is being carried out correctly.

Drop Shatter test

The Drop Shatter Test is an indication of how the agglomerate will stand up to Handling , particularly dropping from a height.

  Tumbler Test

The Tumbler Test gives a measure of the Abrasion Resistance and impact resistance of coke.

Weathering

There is no standard to test for weathering, many producers simply immerse the agglomerate in water for four hours and apply hand pressure to see if disintegration takes place. 

Other Properties :

The normal quality parameters used to measure the quality of coal and coke can be applied to agglomerates. Analysis for

1. Volatile Matter

2. Calorific Value

3. Sulphur

4. Ash content

Can be carried out using the appropriate standards without modification

Progress Till Now Successfully completed testing and analysis of coal properties.

Collection of all the binders to be used from various industries waste-

Lignin-Paper industry

Molasses-Sugar industry

Slurry Waste-Dairy industry

Corn starch-Food industry

Pitch-Petroleum Industry

Fabrication of the mould for mechanical press with load around 2-4 tons. For compressing.

Presently with properties of molasses started the briquetting techniques.

Plan of Action

Time Part of Work to be Covered

By 15th March Production & processing of coking Coal using different binders.Mixing, Heating, Evaporation, Compressing, cooling.

By 30th March Testing & Analysis of final briquetting coal obtained. -Proximate Analysis -Moisture Test -Calorific Value Test

By 20th April Analysis, Comparison of the data obtained & final Result & Conclusion of the project.

Reference Komarek K.R Inc.-The briquetting Process.[1] New Application of Roller Pressure in Coal related Technologies

18th Int. Conf. Coal Utilization And fuel systems-Dr- Ing Pietsch W.[2]

Binders for Fuel Briquetting- A Critical Survey CSIRO, Technical Communication-Waters PL.[3]

Greenfields Develops New Techniques For Recovery Coal Fines-By Steve Ficor

Kela Energy- Orlando, FL Briquetting. (n.d.). Retrieved from

http://www.greenfieldscoal.com/briquetting.php Handled like coal, cost effective, increased preparation plant yield.

(n.d.). Retrieved from http://www.kelaenergy.com/coalProducers.html

A. Dilo Paul, Senior Scientist, Science Applications International Corp.6th US-India Energy Dialogue,2009