COAL CONSERVATION BY

USE OF THERMACT, A

COMBUSTION CATALYST

AT

NALCO DAMANJODI

BY

SUBHENDRA SEKHAR MISHRA

AGM(MECH), SPP

NALCO,DAMANJODI

THERMACT A MULTIFUNCTIONAL COMBUSTION CATALYST

POWER SECTOR

CAN BE USED IN

AFBC, CFBC & PF FIRED BOILERS

(15 MW to 830 MW)

DOSING

THERMACT was dosed @ 1:15000 kg/kg basis (1 kg THERMACT for 15000 kg of Coal) along with the coal, with the help of screw feeder as shown.

INTRODUCTION

Cost of fuel decides production cost of steam

Fluctuating daily

Quality is detoriating

Need of the Hour is emission level

WHAT IS THERMACT

A multi functional thermo active powder developed to improve the combustion efficiency of solid fuels used in TPS

Helps in complete combustion of coal

Reduces un burnt and black smoke emissions

BENEFITS

Increases yield of CO & H2, thereby aiding reduction process

Reduce fuel consumption by 2 to 5%.

Reduce un burnt in Bottom Ash & fly Ash

Increases ash fusion temperature, reducing accretion in Furnace

Reduce deposits and encrustations on boiler walls.

Clean Combustion Chamber

Reduction in Soot blowing frequency

Reduce Excess Air required.

Reduce Stack Emissions & SPM.

Continue Boiler Operation for longer periods.

Reduction in O2%

Reduction in Flue Gas Exit Temperature

Reduction in R/H and S/H Attemperation

Reduction in Auxillary Power Consumption

NORMAL CONDITION

H2O( inherent moisture in coal) + Heat = Vapour

Vapour condense in the chimney outlet and sensible heat is lost

C in fuel + O2 in air supplied = CO2 + Heat

WORKING PRINCIPLE OF THERMACT

THERMACT reduces the activation energy required to release the Volatile Matter in Coal. This Catalyst, when added with Coal before Carbonization, helps in faster evolution of the Volatiles. Inherent Moisture present in Coal is utilized to generate heat in the presence of Carbon.

COMBUSTION

When Heated

Moist Coal Dry Coal + H2O

In the combustion chamber, coal is in plasma state combustion at elevated temperature. Thermact moves through this grid and breaks the structural moisture to produce Syngas primarily made up of carbon monoxide and hydrogen

C + H2O CO + H2

COMBUSTION

Syngas undergoes subsequent oxidation to generate more heat. The hydrogen of syngas combines with carbon of coal to produce methane, which on further oxidation generates more heat thereby helping in improved combustion of coal

CO + ½ O2 CO2

C + 2H2 CH4

THERMACT

Catalyst 1 Carbon

Inherent Moisture

Catalyst 2

C + 2H 2 CH 4

H 2 O

C + H2O CO + H2

THERMACT

Catalysts

Both CO & H2 are good reducing agents

WORKING PRINCIPLE

WITH THERMACT ADDITION

C in fuel + 2H2O( in coal) = CH4 + O2 + Heat

Formation of methane and oxygen produces heat and reduce air requirement for complete combustion.

As seen in the above reaction, if there is 2x% of moisture in coal, then atmospheric oxygen requirement reduces by x%. Thus load on ID, FD fan is reduced. Energy consumption reduces.

Taking all these factors into consideration, it is seen that on an average fuel consumption reduces by 2% when THERMACT is used(tested in laboratory).

Pre Trial Post Trial Remarks

Average Parameter Without Thermact With Thermact

Trial Period Unit 28th June to 15th

July 14

18th July to 19th Aug 14

Boiler Load (Steam Flow) TPH 172.5 162.6

SH Spray Flow TPH 12.1 9.7 2.3 TPH Reduction

Total Air Flow TPS 183.4 161.8 21 TPH Reduction

O2 AT AH I/L % 5.9 4.7 19 % Reduction

FD - A Fan Current amps 16.0 13.3 2.6 amps Reduction

FD - B Fan Current amps 14.5 14.4 0.1 amps Reduction

ID - A Fan Current amps 30.3 25.6 4.5 amps Reduction

ID - B Fan Current amps 32.9 29.0 3.8 amps Reduction

Flue Gas Temp. at Boiler Bank

0C 487.2 476.0 11 0C Reduction

Flue Gas Temp. at ECO I/L 0C 482.8 475.8 7 0C Reduction

Flue Gas Temp. at ECO O/L 0C 388.6 386.4 2 0C Reduction

Flue Gas Temp. at APH O/L 0C 175.6 176.4

Unburnt in Bottom Ash % 11.34 4.89 57 % Reduction

Unburnt in Fly Ash % 1.90 0.88 53 % Reduction

Coal GCV kcal/kg 3923 3457 466 kcal/kg Less

Steam to Air Ratio 1.06 0.99 6 % Reduction

Steam to Coal ratio 3.76 3.44

Steam to coal ratio with respect to same Coal GCV

3.76 3.91 3.9 % Reduction in

coal

Boiler Efficiency % 81.35 83.52

Improvement in Efficiency %

Post Effi - Pre Effi )/ Pre Effi x 100

2.67%

Cost benefit analysis for 19 days

•Total Steam produced in Post trial period : 73966 Tons

•Improvement in Steam to fuel ratio : 3.91 – 3.76 = 0.15

•Total Coal Saved : 0.15 * 73966 / (3.76 * 3.91) =755 Tons

•Cost of coal per ton : Rs 2800/- Ton

•Total Saving in coal : 755 x 2800

= Rs 21,14000/-

•Total Saving in Power = 105.55 Kw / Hrs

•Cost of Power = Rs 2.40 / Kwh

•Total monetary saving in power = Rs 105.55 * 24 * 19 * 2.4= Rs 1,15459/-

•Total gross monetary savings = Rs 21,14000 + 1,15459= Rs 22,29,459/-

•Thermact Cost = Rs 6,60,000/-

•Net Monetary Saving =Rs 22,29,459 – 6,60,000

= Rs 15,69459/-

2.70 %

Improvement

Total Steam produced in Post trial period

Improvement in Steam to fuel ratio

Total Coal Saved

Cost of coal per ton

Total Saving in coal

Total Saving in Power

Cost of Power

73966 Tons 3.91 – 3.76 = 0.15 0.15 * 73966 / (3.76 * 3.91) = 755 Tons Rs 2800/- Ton 755 x 2800 = Rs 21,14000/- 105.55 Kw / Hrs Rs 2.40 / Kwh

Cost benefit analysis for 19 days

Total monetary saving in power

Total gross monetary savings

Thermact Cost

Net Monetary Saving

Rs 105.55 * 24 * 19 * 2.4 = Rs 1,15459/- Rs 21,14000 + 1,15459 = Rs 22,29,459/- Rs 6,60,000/- Rs 22,29,459 – 6,60,000 = Rs 15,69459/-

Cost benefit analysis for 19 days

ADDITIONAL BENEFITS

Substantial reduction in smoke

Non sticky flyash

Gray colour flyash

Whitish bottom ash

Reduction in clinker deposits

Bright yellow flame instead of reddish orange flame

INSTITUTIONAL

CERTIFICATION

Govt. & Pvt. Institutes / Laboratories

INSTITUTES CERTIFICATIONS

Indian Institute of Technology, Mumbai

Fully safe for industrial applications, as all the ingredients in preparation of THERMACT are organic in Nature.

Central Mining Research Institute, Dhanbad

Decomposition of coal was faster with THERMACT with less residual matter.

Central Mechanical Engineering Research Institute, Durgapur

No adverse effect of THERMACT on Boiler Tubes in Bandel TPS after 3 years of continue usage of THERMACT in 210 MW units.

SGS, USA

Conducted Toxicity Characteristic Leaching Procedure (TCLP) test. Confirming ingredient in THERMACT are environment friendly.

Jadavpur University Reduction in unburnt carbon Ash and better heat value with THERMACT.

Technical University of Ostrava, Energy and Research

Drop tube test, Unburnts in Carbon

Indian Institute of Technology, Bombay

Manufacturing Unit at Baddi, Himachal Pradesh

THANK YOU