Energy Conservation through Automation of Energy Conservation through Automation of Processes in Pulp and Paper industryProcesses in Pulp and Paper industry

Applicability of Energy Conservation Act 2001 to Pulp and Paper Applicability of Energy Conservation Act 2001 to Pulp and Paper industryindustry

Pulp and Paper industry is one of the designated consumers as per EA Act, Paper industry is the six largest consumer of commercial energy in the country

Energy cost accounts for 25% of the total manufacturing cost in paper industrySpecific energy consumption in India is high in comparison of developed countries

Lot of scope for improving energy consumption by implementing energy efficient processes and equipments and thereby improving profitability

Advanced process control (APC) is one of the options for reducing process variability and specific energy consumption

Paper industry: the manufacturing processPaper industry: the manufacturing process

Paper Making MachinePaper Making Machine

Recovery SectionRecovery Section

FEED PREPARATION

Wood Yard

Wood From Different sources

Sawdust to hog boiler

Active alkali

Steam

Digestion

Oxy delignification

Washing

Refining

Bleaching

Digestion

Oxy delignification

Washing

Refining

Bleaching

oxygen

Water

Chemicals

PowerFillers Steam

ChippingDebarking ScreeningChippingDebarking ScreeningDebarking Screening

Steam

WBL

Water

Final product Paper

PulpingWhite liquor

Lime stone

Makup salt cake

Fuel

Recovery Boiler

Multiple effect

Evaporation

Re-causticizing

Whiteliquor

storage

Filtration

Kiln

Greenliquor

steam

HBL

MudRecovery

Boiler

Multiple effect

Evaporation

Re-causticizing

Whiteliquor

storage

Filtration

Kiln

Greenliquor

steam

HBL

Mud Greenliquor

steam

HBL

Mud

Flow boxWirePressDrierPress sizeCalandarReelingRewinder/Sheeter

Flow boxWirePressDrierPress sizeCalandarReelingRewinder/Sheeter

Pulp & paper making – ChallengesPulp & paper making – Challenges

Typical characteristics of this industry: -• Capital intensive industry – needs huge investment• Energy intensive industry – Most of the operations are

energy intensive• Environmental non-friendliness – Large quantity & high

COD / BOD values Characteristics of processing

• Long process chain – many unit operations• Large lag times• Uncertainty of raw material composition• Interdependent operations• Multivariable interactions in almost all the operations

Pulp & paper making – Looking forPulp & paper making – Looking for

Reduce specific raw material, energy usages Reduce production cost Reduce quality variability Maximum utilization of the assets/equipment Reduce wastage Comply the regulatory norms Complete information of the processes

Energy Consumption in Pulp & paper industryEnergy Consumption in Pulp & paper industry

Steam: 8.00 tons/ton of finished paper

0.9, 11%

0.3, 4%

2, 24%

0.8, 10%0.5, 6%

1.9, 24%

1.4, 18%0.2, 3%

Pulping & washing

Bleaching

Black Liquor Evaporation

Chemical recovery boiler

Recausticising & Limekiln

Paper machine

Deaerator

Miscellaneous

Energy Consumption in Pulp & paper industryEnergy Consumption in Pulp & paper industry

Power: 1300 KWh/ton of finished paper

1% 4%8%

8%

44%

13%

5%

8%

5%

4% Chippers

Digester house

Washing and Screening

Bleaching plant

Stock preparation + Paper machine +Finishing

Pow er boilers

Intake w ell + Water treatment plant

Recovery (Evaporate, recovery boiler,causticisers and lime kiln)

Eff luent treatment plant

Lighting and w orkshop etc.

What is APC?What is APC? A process control ‘solution’ that

Overcomes shortcomings of conventional single-loop control systems

• Multivariable interaction• Plant constraints• Dead-times• Lack of measurements

Maximizes process performance ‘without addition of new capacity’

Takes control of the plant and directs level-1 system

A software ‘solution’ that Communicates with level-1 system Comprises of high-end algorithms

• Process models• Optimization algorithms• Process variable estimation (Soft-sensors)

Requires no additional Hardware. Leverages existing process instrumentation.

Plant Automation Solutions - FocusPlant Automation Solutions - Focus

Information flow to ensure synchronized supply chain, production plans linked to plants, shortened order-dispatch cycles.

Integration with Planning Layer, Industry Standards – MESA, ISA95

Control of the entire production process ensuring optimum utilization of available resources.

Plant systems & process mapping, MES architecture design, implementation.

The control knowledge (Technology) is built into the system in the form of a model. The system is intelligent enough to effect control on its own.

Development and deployment of Advanced Control technologies, algorithms (like MPC, Fuzzy, Neural Networks)

Operator control using technology as an enabler. The control knowledge rests with the Human (Operator)

Development and deployment of Supervisory Control systems, Creating Process Graphics, Tag databases, Interfacing with PLCs,

PLC’s, DCS’, PID and On-Off control, Recipes

PLC/ DCS Programming and commissioning, System Integration with Field instruments, PID Tuning

All the field equipment like motors, transducers, solenoids, drives

Commissioning of H/W, Solenoids, valves, motors, drives and their interfacing

Level 3 - MES

Level 1- Basic Control

Level 0 - Sensors and Actuators

Au

tom

atio

n H

iera

rch

y

Integration to ERP

Optimizing Control

Level 2

Supervisory Control

APC

L1

Process

L1

L 3

L1

L2

L 2

LoopLocal control (single variable)

CascadeIndirect control (single variable)

SupervisoryMultiloop control (Optimization)

Simulation, Monitoring &Diagnostics (plant wide)

KnowledgeKnowledgeBaseBase

DCS/PLCLevel

APC’s position in automation hierarchyAPC’s position in automation hierarchy

What does APC offer?What does APC offer?

Looks at entire process unit as single entity to be controlled

Uses process models (knowledge) Models capture multivariable interactions

Controls ‘now’ and ‘in future’ Uses predictive power of models

Optimizes performance Achieves balance between throughput & quality Honors process constraints Reduces variability in operation

Facilitates feedback control ‘Soft-sensors’ can be used to estimate important

unmeasured process variables

Soft-sensors: Measure the unmeasuredSoft-sensors: Measure the unmeasured

Soft-sensors ‘Soft-sensing’ is prediction of output variables

using instantaneous values and history of the input-output variables on a pre-defied horizon

Soft-sensors have a mechanism to incorporate periodic correction in the predicted value

• Availability of off-line measurement facility• Possibility of adaptation of the sensor parameters for

performance improvement

Crucial for situations where the control frequency is greater than the measurement frequency

Stabilize and OptimizeStabilize and Optimize

80

85

90

95

100

105

Before APC APC On line Target Moved

Lim

it/%

S pec ification lim it

Reduced S tandard Deviations

APC & optimization opportunities APC & optimization opportunities

in pulp & paper industryin pulp & paper industry

APC solutions in the following areas Continuous and Batch Digester Recovery section

• Recovery boiler• Rotary lime kiln• Evaporation section

Re-causticization Bleaching section Paper machines optimization Hog Fuel boiler

Optimization solutions Deckle matching & optimization Digester scheduling & optimization

Optimization in pulp & paper making Optimization in pulp & paper making

Examples of opportunities for Examples of opportunities for reduction in energy reduction in energy

consumption by implementing consumption by implementing APC in Paper and Pulp IndustryAPC in Paper and Pulp Industry

Chemicals

PowerFillers Steam

Final product Paper

Wood From Different sources

Sawdust to hog boiler

Active alkali

Steam

Digestion

Oxy delignification

Washing

Refining

Bleaching

oxygen

Water

Steam

WBL

White liquor

Lime stone

Fuel

FEED PREPARATION

Recovery Section

WaterMakup salt cake

Pulping

Paper Making Machine

Wood Yard

Flow boxWirePressDrierPress sizeCalandarReelingRewinder/Sheeter

ChippingDebarking Screening

Recovery Boiler

Multiple effect

Evaporation

Re-causticizing

White liquor storage

Filtration

Kiln

Green liquor

steam

HBL

Mud

Recovery section: needs and challenges Recovery section: needs and challenges

•Maximize through puts•Improve Steam economy•Reduce variability in HBL conc.•Optimum thermal and combustion efficiency •Reduce down time• Minimize SEC in Kiln•Recover maximum amount of NaOH

-Un measured chemical concentrations -HBL’s scaling tendency reduces the effective heat transfer -Inorganic in HBL deposits at the surface of tubes causing ineffective heat transfer-Ring formation inside the kiln

Chemicals

PowerFillers Steam

Final product Paper

Wood From Different sources

Sawdust to hog boiler

Active alkali

Steam

Digestion

Oxy delignification

Washing

Refining

Bleaching

oxygen

Water

Steam

WBL

White liquor

Lime stone

Fuel

FEED PREPARATION

Recovery Section

WaterMakup salt cake

Pulping

Paper Making Machine

Wood Yard

Flow boxWirePressDrierPress sizeCalandarReelingRewinder/Sheeter

ChippingDebarking Screening

Recovery Boiler

Multiple effect

Evaporation

Re-causticizing

White liquor storage

Filtration

Kiln

Green liquor

steam

HBL

Mud

RecoveryRecovery section : Multiple effect Evaporation APC section : Multiple effect Evaporation APC

Multiple effect evaporator• Consistent HBL concentration

•Improve steam economy/Minimize steam consumption• Maximize through put

• Decrease down time due to exchanger cleaning

•Feed flow rate•Steam flow rate•Vacuum

•Inlet concentration•Steam header pressure

•Solids Concentration•Temperature profile•Vapor separator levels•Solids throughput

Disturbance Variables

Manipulated Variables Controlled VariablesOptimizer Process

Model

Soft-sensor

Processoutput

Desiredoutput

+

-

TYPICAL CONTROL STRATERGY FOR EVAPORATRS

What does APC offer?What does APC offer?

Improvements achievable due to APC depend on process conditions

Process complexity, variability, raw material variations, low frequency of feedback implies scope of higher benefits

Benefits Higher throughput: Increased throughput without addition of

new capacities. Typical 2-10% throughput increase Minimize energy consumption: Reduced energy / fuel

consumption. Typical 5-10% reduction Reduced raw material consumption: Typical reduction of

fibre and additives 1-5% Consistent quality: Consistent & improved product quality.

Typical variability reduction 20-50% Reduction in off-spec production during grade change:

typical 10-20% Smooth operation Higher availability of plant (reduced downtime) Overall lower cost of production

Kiln OptimizerKiln Optimizer India’s largest cement manufacturerIndia’s largest cement manufacturer

The ChallengeThe Challenge India’s largest

kiln: rated at 10,000 TPD

Stabilization and complete automation of operations

The BenefitsThe Benefits Reduction in average specific fuel consumption by 6.5 kCal/kg Reduction in variation of clinker quality (free lime and liter weight) by

~60% Improved clinker grindablity in cement milling operation Zero operator intervention

The GoalThe Goal Rapid stabilization Increased throughput Reduced specific fuel

consumption Consistent clinker

quality Smoother operation

of key process units

The SolutionThe Solution CemPac – TCS’ proprietary

multivariable controller (MPC) Online switching to heuristic

controller for abnormality handling Unique softsensor for on-line

prediction of free lime, liter weight Built on TCS’s in-house Advanced

Process Control (APC) Toolkit

ChallengesIncreased productivity Increase use of alternative fuelsCreate a corporate culture of continuous improvementConsistently reduce operating costs significantly

Results DeliveredIncreased use of alternative fuels

Reduce use of lignite as much as 14% Increased productivity

Achieve kiln run time of as much as 90%Fewer kiln trips due to high temperature Fewer fuel trips

Reduce NOx EmissionsBetter temperature control

Increase production by as much as 4.5% (if not trying to maximize alternative fuel use)Improved Free Lime Control

Lime kiln APC SolutionsLime kiln APC Solutions

Thanks!Thanks!