Emerging Best Energy Practices in Seshasayee Paper related to
Cross –sector application
Dr T.G.Sundara Raman Seshasayee Paper and Boards Limited
2nd National Workshop for Promoting Energy efficient & Cleaner Production for Sustainable Industrial growth
BEE/IIP/BHC
New Delhi 9th March 2018
ENERGY SECTORS - PAT A. Thermal Power plants
B. Iron & Steel
C. Cement
D. Fertilizer
E. Aluminium
F. Pulp & Paper
G. Textile
H. Chlor-Alkali
I. Petroleum Refinery
J. Sugar
Independent Captive Power Plants
Cross – Sector Energy Scheme Exchange
S
P
B
Circular /Linear Economy : Cross-Sector
WASTE/RESOURCE Management
Plant Waste
Linear
Economy
---------------------
Reduction
Circular
Economy
-----------------------
Elevation to
Resource
REPLICATION
Within the
Plant
Within the
Sector
Across the
Sector
Best Energy Practices for Replication in Other Industries [ Cross –Sector Application]
• Successfully Implemented Schemes A
• Schemes under Implementation B
• Emerging Schemes Planned for Implementation in near future C
SPB Unit : Erode
Best Energy Practices
•Successfully Implemented Schemes A
Multi-Sector Cascading from Waste {of Paper Sector} to Resource{ for Cement Sector}
CPP Coal fired Boiler Paper Mill
Waste Bottom/flyash
from Boiler
Bottom ash [ Low LOI] supplied to Cement Industry
Used as Clinker aggregate
Cement-Final Product
400 TPD
Ash : 4 %
LOI redn.from 12-14% to 6-8%
15 TPD
~10 TPD
Combustion effy incr. by 0.5%
AFBC Boiler [# 10 ] Air & Flue Gas Diagram
Waste to Energy Conversion
Boiler #10- LOI redn. in Bottom-flyash ----------------------------------------------------------------------------------------------------
•P.A. pressure reduced from 1400 to
1200 mmWC
LOI in Bottom-Flyash reduced from 12% to 8%
Combustion η incr.by : 0.4 to 0.5 %
Coal saving : 50 to 60 t/m
GHGE reduction: 750 to 900 tCO2e/yr
Easy disposal of FA to Cement mill
Equipment
Steam
Rate
TPH
Efficiency
%
Power
Consumption
Power
Savings
%
Daily
Power
Savings
in Units
Feed pump 90 60 15200 Basis Basis
HE BFP with
Lower
Disch.Head* 95 77 12000 21
3200-
3400
HP Chemical Recovery Boiler Feed Pump
8
* : Lower Discharge Head with Lower DP Control Valve in place
Spin-off Benefit: HPSteam : 6 TPD
Replication : All Sectors
Maximizing Cycle Efficiency with Waste heat recovery through
Exhaust steam Vacuum-Dryness fraction integration in 21MW Steam Turbo-Generator
Technology and Working of Innovation • In Steam turbo-generators related to exhaust
steam in condensing mode, the heat to power conversion ratio is invariably low [ poor low turbine heat rate] with the heat rejection- due to latent heat- from exhaust steam condensation to cooling water in closed cycle being of a very high order. The innovation concept focused on maintaining lower exhaust steam dryness [89% to 93 %] alongside conventional improved condenser vacuum in maximizing Power generation without additional energy intake.
• With around DF gain of over 1% from otherwise wasted exhaust steam , the electrical Power conversion realized is –
from 0.15/0.2 MW [ at lower condensing loads]
to 0.25/0.32 MW [ at higher condensing loads].
21 MW STG Exhaust steam Dryness
Fraction –Snap shot
Cross- Sector Replication
• Paper & Pulp Sector
• Industrial CPP & Thermal Power PlantsPlants.
.
Process condensate polishing
Waste heat recovery through PHE
Condensate polishing resin bed
ACF MB
ST
FWT
Process Hot / Condensate Tank
Filter
Polished Condensate
To Deaerators
PHEs Hot
Fluid
Process Condensate : 90°C to 40°C
DM Water Preheating : from 32°C
Heat Recovery : 4 MWt
CPU+ HRU - INTEGRATED WATER & ENERGY MANAGEMENT -BOILERS [CFB & CRB]
Replication : Sectors with HP Cogen Boilers
Green Power – Export
& LP steam- Process
Bagasse- Fuel in
HP Cogen
Cane Milling for Juice extraction
& Bagasse
Sugar cane to Ponni Sugar Mill
Lift Irrigation for Sugar-Cane
Growth
Little Green Power used for
lift irrigation
Waste Effluent to Renewable Energy
Cycle
Residual Waste: Minimal
Waste Effluent Discharge Eutrophication
Impact Reduction
Circular Economy
Treated waste water for Sugarcane irrigation Ponni
Sugars Bagasse (of SPB) fired in HP cogen
Generation of Green Power Green Power (0.5 MW) Export Replication : Paper-Sugar
Complex
Parameter Present Earlier
Heat Exchanger SHE Shell &
Tube
White liquor outlet
temperature
100-120 C 85-100 C
Hot white liquor
temperature [with
Fouling/Corrosive ]
140-145 C 120-125 C
LP steam saving 2 TPH Basis
Emission Reduction 2000 tCO2e Basis
Advanced Energy Scheme for Fouling Fluid
SPIRAL HEAT EXCHANGER Performance Feed-back- RDH Station
.
Replication: Sugar,PC& Fert.
Innovative WHR Schemes
Hot Air Dissipation in SPB
STG
Generator Air Cooler
HRU
RLK
Satellite Cooler
HRU
AC-CPP
Oil Cooler
HRU
First of its kind
Air Compressor - Heat Available for Recovery
To
tal p
ow
er
100% 90%
A
vl h
eat
5% heat from drive motor
13% heat from After cooler
76% heat from Oil cooler
2% heat inside the canopy
2% heat radiated through canopy
Oil & Lubricant Cooling through Ambient air but Hot Air is being discharged into atmosphere. Not utilized in Process
Replication : All Sectors
Waste Heat recovery- Schematic
Waste heat recovery
MB
ST
FWT
Oil Boiler Feed Water
To Deaerator
PHE
Screw Air
Compressor
INNOVATIVE PROJECT
Elgi Screw Air Compressor – Water cooled HRU Micro PHE
ECS –AC –HRU COMBINE-
RECOMMENDATIONS
• Waste heat from Air Compressor [AC] is gainfully converted to usable energy through Boiler Feed water heating
• Not only the new Air compressors need be fitted with integrated HRU, but also HRUs should be added to the existing energy guzzling AC to suit.
• Stage is set for recovering the heat from after-cooler.
CPP-Boiler 10
Sonic Horn – Performance Enhancement OF CFB-CPP
HP Coal Fired Boiler
SH coil kept clean
Steam saving
Dedusting of SH Coil Exterior
Superheater Coils
Replication : Sectors with Solid fuel fired Boilers
Best Energy Practices
•Schemes under Implementation
B
Paper Machine- Yankee Cylinder ECS through arresting Radiation heat loss
. State of the art Insulation of Dryer end
• Drying Cylinder Length : 3.65 m
• Radiation heat loss across DC ends: 8-10%
• Insulation of DC ends : Mattress containing special Ceramic long fibre
• Double layer insulation
• Steam saving est: 2 TPD
Spin-off Benefits
# Uniform DC surface temperature across entire length
# Product quality enhanced
# Operators comfort from heat of radiation
Replication :Sugar
CPP –CFB-Exhaust Flue Gas HRU
ESP
Flue Gas
exhaust –
Condensate HX
• TG Condensate heating : 10 °C
• FG Exit Temp. : 130-132 °C
• CPP-Cycle η enhanced
• Deaer. Steam con. redn: 15 TPD
• Emissio redn: 100 tCO2e/m
ID
Fan
Flue Gas
Flue Gas
Replication : Coal fired Boiler
Best Energy Practices
•Emerging Schemes Planned for Implementation in near future
C
CPP: 21 MW DEC STG - INNOVATIVE ECS
DM water switch related to heat recovery from Turbo-generator winding heat dissipation for increased Cycle efficiency
Demonstration successfully done . Getting Ready for Implementaton on a continuous basis
Proposal: DM water- instead of cooling tower circulation raw water- is to be supplied to generator air cooler and is returned to the Deaerator at a higher temperature, thereby reducing LP steam.
23
STEAM
TURBINE
DM WATER IN
DM WATER OUT
G
GENERATOR AIR COOLER
PLANNED
REPLICATION POTENTIAL : Steam turbines with condensing units related to Cogeneration can take advantage of the scheme through implementation . Concept can be suitably modified for Thermal Power plants by utilizing turbine condensate instead of DM water.
BENEFITS ESTIMATED: • Deaerator steam consumption redn: 12 TPD
• GHG emission redn :1100 tCO2e/annum • Fouling of generator air cooler tubes is avoided
• Enhanced winding temperature reduction.
Radiation Heat Recovery –Hot Air to Boiler water heating
.
Parameter Units Value
Radiation Heat
transfer from
RLK-SC Exterior
Mkcal/day 4 -5
SC Surface temp. °C 280-310
Feed water inlet
temp. to HRU
°C
60
GHGE Reduction tCO2e/yr 500
LP steam saving TPD ~ 7
WHRS Proposed to capture Radiation & Convection heat from Satellite Cooler [SC] exterior of Rotary Lime Kiln[FLS]. The surface temperature of the SC is around 310°C. HRU panel enclosing the existing Rotating Satellite Cooler unit shall be in place so as to capture the heat of radiation. This radiation heat shall be captured by the boiler feed water for preheating & then on led to storage tank of CRB [ Boiler # 11].
Replication Sector : Cement Plants
CONCLUSIONS
• SPB had led the way for Cross-sectoral Energy [Industry] schemes implementation with minor/no modification
• Unique Waste Energy Low grade Heat Recovery schemes successfully implemented/in pipe-line.
• As for the Paper & Pulp Sector & CPP/IPPs, the stated Energy schemes can straightaway be implemented in their plants.
• Circular Economy : Waste from One Sector is to be used as valued Resource in same/cross-sector
Paper & Pulp
Sugar Mill
Paper Mill
CPP
Cement Plant
SUN
CO2
Tree Farming
Effluent
Bagasse
Bottom
Ash
Pith
Cross-Sector Waste to Resource
Multi-Sector Cascading
The new concept envisaged and successfully implemented relates to – • Waste to conversion of multi-industrial sectors. • Waste from one sector serves as resource of other sector; • This in turn yields waste which in turn becomes the resource for third sector; • Finally the waste from this plant serves as resource for yet another sector
WAY FORWARD
• In similar fashion there should be transfer of Knowledge from other Sectors in terms of Advanced Energy schemes successfully implemented for gainful use of the receiving sector with little/no modification
• Through Cross-sector Knowledge exchange, the Energy Intensity as well as Emission reduction shall comfortably be achieved.
Clean , Green & Strong
Continuously strives for improving the 3 Es-
• Energy Conservation
• Environment Control &
• Emission Reduction
On a Sustained and Continuous basis
ECS Replication in Recovery Complex
Proposed Spiral Heat Exchanger In pipe-line for Implementation
.
Parameter WBL [14%con.]
Evap. Steam condensate
Inlet Temp. 90 67-68
Outlet temp. 82 78-80
Heat Exchange
1 Mkcal/h
LP steam saving
~60 TPD
Emission reduction
~4000 tCO2e/yr
Waste Heat Recovery from Energy efficient Air Compressor
Micro-PHE attached to Screw Air Compressor exhaust
Energy & Emission Gains
• Annual Energy saving : 800-900 t LP Steam
• Carbon Emission reduction : ~170-190 tCO2e/yr
Boiler feed water : 2 TPH Heating from 30 to 70 C
Heat Recovery : 0.075Mkcal/h