boilers for plant waste-rajavel

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Steam generators using

Industrial waste as Fuel

J. Rajavel

Thermax Ltd

Outline

Type of Industrial Waste

Characteristics of Waste

Thermax Incineration route

Challenges in the Boiler design

Overall benefits to customer

Type of Industrial waste

Distillery Plant waste

Coffee Plant waste

Steel Plant waste

Paper Plant waste

Viscose Plant waste

Refinery Plant waste

Oil Mill / Oil extraction

plant waste

Saw mill plant waste

Tyre plant waste

Poultry waste

Other coal / coke

washery plant waste

Distillery Plant waste as fuel

Spent Wash - Spent wash fired boiler

Biogas – Bio-gas fired boiler

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Raw Spentwash-The Back end What is Spentwash?

All spirits go through at least two procedures -

fermentation and distillation. Fermentation is where

all alcohol is created, distillation is where the alcohol

is separated and removed. In order for fermentation

to occur, two things are needed

YEAST + SUGAR(molasses) = ALCOHOL + CO2

Spent wash is a brown liquid-waste that is generated

as a by-product during the distillation of fermented

molasses

A typical distillery generates 8 to 15 litres of spent

wash per litre of alcohol

Spentwash Characteristics Vs Issues

Varying solids content in raw spent wash.Acidic in nature

•Highly viscous at solid concentration >60%Spentwash concentration required is 55-60%solids to ensure bed stability and energy economics.

•High alkali content in ash leading to fouling of

heat transfer surfaces

High amount of chlorides leading to high temperature corrosion of super heater

Process Waste

High Moisture

High Alkali

High Chlorine

CHARACTERISTICS ISSUES

Mode of Disposal

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Disposal Methods

Bio Methanation

Higher residual Liquid Discharge

70% energy conversion in Biogas

Composting

Huge area requirement

Land pollution due to leaching

Poor Commercial returns

Disposal problem during rainy season(open yard operation)

Incineration

100% SPW disposal

Steam to Process

Power Generation

Marketable Potash rich Ash

Why spent wash boiler

Zero Liquid Discharge norm has been implemented

Existing methods unable to meet ZLD

Bio-methanation

Bio-composting

Ministry of Environment and Forests

EIA study and pollution control methods

Spent Wash Characteristics

HighMoisture

HighDust

ProcessWaste

HighAlkali

HighChlorine

Design Considerations

Zero effluent discharge

Bed agglomeration

Spentwash spray system

Residence time

Online scale removal

NOx, CO reduction

Deep fluidised bed combustion

Proper proportioning of coal for

reducing the base-to-acid ratio

Location, cone-angle, droplet size

Two-pass furnace

Mechanical rapping

Suitable sizing and positioning of

secondary air, tertiary air ports

Challenges Solutions

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Concentrated Spentwash Analysis

Ash Analysis

(%)Silica as SiO2 20.91

Iron oxide as Fe2O3 1.81

Calcium oxide as CaO 8.24

Magnesium oxide as MgO 6.95

Sulphate as SO3 8.41

Phosphate as P205 1.64

Potassium oxide as K2O 43.19

Sodium oxide as Na2O 2.76

Aluminium oxide as Al2O3 0.08

Titanium oxide as Tio2 0.01

Chlorides 6%

Ultimate Analysis (%)

Carbon 22.93

Hydrogen 2.21

Oxygen 15.22

Nitrogen 1.91

Sulphur 0.60

Moisture 40.00

Mineral matter 17.11

GCV 1,860 (kcal/kg)

Basic concepts...

Spent wash concentration - 60% solids

Spent wash to coal ratio - 20% by weight

Why coal as support fuel

General Arrangement Pressure part arrangement

To bag filter

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Spentwash Boiler at Bannari Amman

Sugars-Mysore

ASH REMOVAL BY RAPPING

MECHANISM

Concentrator

Spray cap

Roof Jumpers

I pass rear wall header

Spentwash firing Arrangement

Cooling air Conn. From SA header

Spent wash gun

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CFD based Spray/Emission optimizationSpentwash Spray System Design of spentwash spray system for its spray gun location in furnace, spray cone shape and droplet size through pilot testing/CFD

Emission ControlOFA system optimization and furnace temp. prediction through CFD/KED modeling

Benefits to Customer

Customer meeting ZLD norms

Generation of captive power and steam to run Distillery

Continuos distillery operation with continuos consumption of

Spentwash

Alkali rich Flyash being shall be disposed to fertilizer

companies/Farmers

Every kilogram of concentrated spent wash replaces nearly 0.33

kg of Indian coal,CDM benefits to Customer

Byproduct from ETP, lowers fuel costs as it

replaces more expensive fuels

What is Biogas Distillery Plant waste- Biogas

Biogas composition

Methane CH4 - 50-55%

H2 S - 2.7%

CO2 - 35 -40 %

Moisture - 2- 10%

Heating Value – 4000 – 5100 Kca/Nm3

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Bio-Gas Characteristics Vs Issues

Varying Heating value of biogas.Acidic in nature

•Sustaining the Flame / Flame stability Oil support required and energy economics.

•Leads to corrosion in the pipes

•High acid dew point temperature

Lower Heating Value leads to suppression Flame

Process Waste

High Moisture

Sulfur

Lower GCV


Supply pressure from holder low and unsteady. Makes

burner operation unsteady.

During burner OFF cycle, biogas either is vented to

atmosphere or taken to a storage tank. This tank is an extra

capital investment.

Lean (low CV) gas means low radiant heat. Boiler/heater

need larger convection banks than normal. Oil-fired boiler or

heater may not give rated output on biogas firing

Design consideration- Biogas

When biogas & oil are burnt together, oil supplementing balance heat, flame interference causes unstable & incomplete combustion. Burner must be designed suitably

H2S & moisture in biogas corrode gas train & burner components. To prevent corrosion, stainless steel & plastics are required

Dew-point corrosion affects boiler/heater pressure part, duct & chimney

High moisture content in fuel means more heat loss through stack & lower output

Design consideration- Biogas

Thermax has supplied exclusive Biogas fired boilers . Combustion through dedicated burners

Thermax installations are there in biogas combustion in AFBC boiler in combinations with Coal firing in both In – bed nozzle design and Burner design

Thermax has supplied Traveling grate / Dumping grate

Bagasse fired boiler with Biogas burners.

Distillery Plant waste- Biogas

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Steel Plant waste as fuel

Char - Char fired AFBC / CFBC boilers

Blast furnace gas –

Coke oven Gas-

Corex Gas

Char / Dolochar - as fuel

What is Char-

Sponge iron Kiln byproduct

Steel Plant waste- Char

CHAR Ultimate Analysis

Carbon – 16.0 to 26.0% Volatile matter – 2 to 7%

Hydrogen- 0.20 to 0.75% Iron content in ash – 0.5 to 4%

Nitrogen- 0.25 to 0.75%

Oxygen 2.0 to 4.5%

Ash - 60.0 to 70 %

Moisture – 3.0 to 9.0%

Sulfur dioxide -0.20 to 0.30%

Heating Value – 1100 to 2300 Kcal /Kg

Char Characteristics Vs Issues

Varying Calorific value of Char.

•De-fluidization of bed

• Accelerate the erosion in furnace zone

•Difficult to combust

Bed / Bottom ash disposal

Process Waste

Iron content

Lower Volatile

High Ash


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Design Considerations- Char

Disposal of Char

Bed agglomeration

Combustion system

Sustaining the combustion / Bed

temperature

Erosion in pressure parts

Frequent bed drain

Ash disposal system


Proper sizing of char and monitoring the iron

content in the char

Hopper bottom AFBC / CFBC technology

Blending with high volatile solid fuel

Studded arrangement / refractory

Open hopper bottom design

Water cooled bed ash coolers / Pneumatic bed

ash coolers


Open hopper bottom

AFBC

Open hopper bottom

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SALIENT FEATURES OF

HOPPER BOTTOM DESIGN1. REGULATED / CONTROLLED DRAIN.

2. BED DRAINING CAPABILITY FROM THE ENTIRE

BED AREA.

3. HEAVIER PARTICLES LIKE IRON CAN BE REMOVED

FROM THE RUNNING BOILER

4. BED DEFLUIDISATION AVOIDED.

5. BED PACKING IS AVOIDED DUE TO DRAINING

FROM ALL THE AREAS OF BED.

SALIENT FEATURES OF

HOPPER BOTTOM DESIGN6. LOWER BED DRAIN RATES. LESS BED MATERIAL

MAKEUP.

7. HIGHER SIZE CLINKERS ALSO CAN BE REMOVED-

4”-5” FROM THE RUNNING UNIT.

8. ENLARGEMENT OF CLINKERS CONTROLLED.

9. STARTUP CLINKERS CAN BE REMOVED.

SALIENT FEATURES OF

HOPPER BOTTOM DESIGN10.HIGH MOISTURE FUELS ARE ACCEPTABLE.

11. VARIETY OF FUELS CAN BE FIRED

12. ENTIRE BOTTOM IS OPEN, FOR MAINTENANCE IT

IS MADE SIMPLE.

Steam generator- Char as fuel

Thermax supplied more than 25 steam generators

with Hopper bottom AFBC boilers for the

incineration of Char.

Thermax Char fired CFBC boiler is under

construction.

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Blast Furnace Gas (BFG)

• TBW and B & W have rich experience of supplying

Boilers for the Steel industry.

• These Boilers are designed to handle typical Steel

industry lean Gases like Blast furnace Gas,Coke

oven Gas, Corex Gas, LD Gas.

• Capacity range: 10 TPH - 500 TPH.

• Pressure range: 10- 100 kg/cm2.

• Temperature range: upto 560 Deg C.

Steel Plant Waste –BFG / Coke oven Corex gas

Characteristics of Blast Furnace Gas

VERY LOW COMBUSTIBLES & CALORIFIC VALUE

SLOW BURNING

UNDETECTABLE FLAME

LOW FLAME TEMPERATURE AND EMISSIVITY

WIDE VARIATIONS DUE TO PROCESS CHANGES IN:

- Pressure

- flow

- Calorific value

LOW SUPPLY PRESSURE

HEALTH HAZARD DUE TO TOXICITY.

DUST AND MOISTURE LOADING FROM

GAS CLEANING PLANT

Salient Features of TBW Boilers

TIME

-VERY LOW VOLUMETRIC HEAT RELEASE RATE:

(LOWER THAN 25000 BTU/HR ft3)

- Ensures complete combustion

-Provides higher residence time in furnace

-Enhances life of the boiler pressure parts.

TEMPERATURE

FURNACE REFRACTORY LINING:

-Ensures temperature necessary for stable combustion of

BFG.

TURBULENCE SCROLL BURNER

- Provides high mixing energy of air & BFG mixing for

efficient combustion

- Provides “spin” to ensure adequate mixing energy.

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Salient Features of TBW Boilers

B&W DESIGN BURNER:

- Own manufactured burners ensuring perfect matching and

integration with furnace geometry.

RICH EXPERIENCE:

- More than 50 similar boilers in operation world wide by B&W.

- 22 operating installation in India by TBW on BFG & other

Lean Gases.

Higher excess air for combustion of BFG.

Zero support fuel within 70-100% MCR with uninterrupted

supply of BFG at constant pressure/ calorific value.

Oil firing back-up if required by Customer.

Highest reliability.

JSW 200 TPH BFG Fired Boiler

TISCO 100 TPH BFG Fired Boiler Photos JSW 80 TPH BFG Fired Boiler Photos

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Burners for 100 TPH BFG fired Boiler at TISCO, Jamshedpur

Burners for 80 TPH BFG fired Boiler at JVSL, Bellary

Paper Plant waste- ETP

Ultimate Analysis

Carbon – 12 to 14%

Hydrogen- 1.20 to 2.00%

Nitrogen- 0.25 to 0.35% Chlorine in fuel - 0.3 – 0.6%

Oxygen 10.0 to 13.5%

Ash - 20.0 to 30 %




ETP Characteristics Vs Issues

Varying Heating value wrt moistre.

• Quenching the bed combustion / Flame stability

•Fuel feeding / stickiness in the feeder

•Corrosion of super heater tubes

Flame stability

Process Waste

High Moisture

High Chlorine

Very low GCV


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Design Considerations - ETP

Combustion of ETP

Flame Stability

Agglomeration property of ETP

Fuel feeding due to high moisture

Soot deposition

Chlorine corrosion in SH tubes

Hopper bottom AFBC technology

Blending of good fuels to maintain the bed

temperature

Hopper bottom AFBC gives flexibility to drain

the clinkers

Shaft less screw and live bottom bin with

stainless screw

Soot blowers

Inconel alloy material construction tubes


CLIENT: - M/S SABAH FOREST INDUSTRIES SDN. BHD. , MALAYSIA

CLIENT: - M/S SABAH FOREST INDUSTRIES SDN. BHD. , MALAYSIA

Viscose Plant Waste - ETPS

Effluent sludge from Viscose plants

Fuel Analysis and its charatecristics

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Viscose Plant waste- ETP

Ultimate Analysis

Carbon – 4 to 6 %

Hydrogen - 0.5 to 0.7%


Oxygen 2.00 to 3.5%

Ash - 13.0 to 15.0 %





Varying Heating value wrt moistre.


•Fuel feeding / stickiness in the feeder

•Dew point temperature

Flame stability

Process Waste

High Moisture

High sulfur

Very low GCV


Design Considerations - ETP

Disposal of ETP

Combustion system

Fuel feeding and storage

system

Flame stability


Hopper bottom AFBC / CFBC

technology

Slurry type conveying system

and Special type screw feeder

Continuous other fuel support


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Oil Mill / Solvent Extraction

Plant Waste -

De oiled bleach oil earth ( Palm oil plant waste)

De-oiled cake fired boiler

De –Oiled Bran fired boiler

Palm wastes – Empty fruit bunch , Palm shell, Palm

fiber fired boilers

Palm oil Plant waste- Spent earth

Ultimate Analysis

Carbon – 11.53 %

Hydrogen - 2.65 %

Nitrogen- 0.09 %

Oxygen 3.8%

Ash - 74.0 %

Moisture – 7.0%

Sulfur dioxide -0.65%

Heating Value – 1100 to 1500 Kcal /Kg Fuel size – 100% less than 0.08 mm


Varying Heating value wrt oil content.


•Fuel feeding / stickiness in the Furnace

•Fouling of pressure parts

Flame stability

Process Waste

High Ash

Fineness

Very low GCV


Design Considerations - DOBE

Disposal of DOBE

Combustion system

Fine ash deposition

Flame stability

Deep fluidised bed

combustion

AFBC technology

Soot blower

Intermittent other fuel

support


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Oil Solvent Extraction Plant –

De-oiled bran Ultimate Analysis DOB

Carbon – 35.81 %

Hydrogen - 2.68 %

Nitrogen- 1.09 %

Oxygen 26.5%

Ash - 16.31 %

Moisture – 11.0%

Sulfur dioxide -0.01%

Heating Value – 2600 Kcal /Kg

Design Considerations - DOB

Combustion system

Ash fouling on heating

surfaces

Fuel feeding and flow ability

AFBC Technology both Flat

bed and Open hoper bottom

design

Soot blower

Special type fuel feeder with

over bed feed system


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Coffee Plant Waste

Effluent from Coffee plants (NESTLE)

Spent Coffee ground (SCG)

Roasted Chaff

Green coffee waste

Coffee waste water

Coffee plant waste – Fuel

characteristics

Coffee waste Characteristics Vs

Issues

Varying Heating value wrt Moisture content.

• Flame / Self sustaining combustion stability

•Fuel feeding / stickiness in the Furnace

• Fouling of pressure parts

Lower IDT / Bed agglomeration

Process Waste

High Moisture

Powdery Fineness

High Alkali content


Design Considerations - SCG

Disposal of SCG

Combustion system

Fine ash deposition

Agglomeration /

Clinkerisation

Fuel storage / Feeding

system

Fluidized bed incinerator

AFBC technology

Soot blower

Sub- stochiometric combn

Live bottom bin with table

feeder system


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Oil refinery Waste - Petcoke

What is Pet coke-

Pet coke is the byproduct of crude oil distillation in

Petroleum refinery plants.

High Sulfur & High Fixed carbon .

Refinery Plant waste- Pet coke

Ultimate Analysis

Carbon – 86.7 % Volatile matter – 5 to 7%

Hydrogen- 3.18% Fixed carbon – 80 -87%


Oxygen 1.16%

Ash - 1.0 %

Moisture – .0.8%

Sulfur dioxide -6 to 8%


Char Characteristics Vs Issues

Varying Sulfur content .

• Sox production is higher.

•Difficult to combust

Combustion temperature band width

Process Waste

High sulfur

Lower Volatile

IDT


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Design Considerations- Char

Combustion System

Bed agglomeration

Load fluctuation

HIGH TEMPERATURE /

SULFUR CORROSION

AFBC / CFBC technology

Proper maintaining bed

temperature and blending with

low IDT coal

High volatile fuel support for

quick response.

Lime stone addition and Special

grade SS material construction


110 TPH CFB Boiler at Sourashtra cements

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Other Industrial waste –

Palm shell / palm kernel/ Palm empty fruit bunch fired boilers-

Pusher grate boilers supplied by Thermax

Saw Dust / Sander dust fired boilers – AFBC boilers have

been supplied by Thermax

Coir Industry waste – Coconut Frond, coir waste fired TG /

AFBC boilers have been supplied by Thermax.

Other Industrial waste -

Oil Mill / Oil extraction

plant waste

Saw mill plant waste

Tyre plant waste

Poultry waste

Other coal / coke

washery plant waste

Thanks for the

attention

boilers for plant waste-rajavel

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