2. 2
What is APC?
• APC = Advanced Process Control
• A traditional control system controls processes to fixed set points
determined by operators. Uses generic control algorithms and instructions
such as a PID controller.
• The purpose of an APC system is to automatically account for an
expected (modeled, predicted…) process response and calculate
“optimal” control actions to minimize process variation.
• APC systems utilize controllers and technologies such as
– Model based control
– Fuzzy logic and control
– Multivariable control
– Adaptive control
– Inferential control
– Process modeling and simulation
5. 5
The Business Challenges
Increased customer demands
Better quality
Greater quantities
Tighter specifications
Higher operating costs
Fuels
Energy
Personnel
Transportation
Increased competition
Internal capital
Other suppliers
How Can Your Business Flourish in this
Environment?
6. 6
Solutions for the Business Challenges
Economic benefits from APC
Throughput increase 4 - 10%
Yield increase 0.1 – 10%
Energy savings 3 - 10%
Variation reduction 20 – 90%
Reduce variation of key process and quality parameters
Increase plant capacity via tighter and smarter controls
React correctly and quickly to changing conditions
8. 8
Issues & Trends
In the times when price of energy is
increasing day by day & dairy plant is
high energy consuming plant we should
look into them first. One of the area can
be the milk powder plant which is based
on spray drying technology which is
very costly way of reducing moisture
from the milk.
Now a days many technologies are
available to make the plant efficient but
very few look into realizing process
potential and achieve performance
excellence with the help of automation
available for industry.
9. 9
Benefits of APC
Advanced automation strategies help to ensure steady
performance of plants. Site analyses of Powder plant
indicate that the various parameters to be maintained are
not always steady.
Moreover the variations of a basic parameter have not always
been accompanied by corresponding proportionate
variations of other related parameters.
This has added to the instability in batch cycle time,
productivity and product consistency of Powder Plant.
10. 10
Commercial Benefits
By using advance automation,
some of the tangible benefits
derived can be :
– Increased Production of
Valuable Products`
– Reduced Energy
Consumption
– Predictable Process
Performance
– Fewer Unscheduled
Shutdowns, Improved
Stability and Longer
Equipment Life
11. 11
Pavilion8
Dryer
Controller
Process
(Manipulated Variables)
Uncontrolled Influences
(Disturbance Variables)
Process Results
(Controlled Variables)
Abs humidity
Feed solids
Dryer Exhaust RH
Solids throughput
Product Moisture
Air flows
Setpoints
(Manipulated Variables)
Uncontrolled Influences
(Disturbance Variables)
Process Results
(Controlled Variables)
Dryer Exhaust Temp
Dryer Inlet Air Temp
SFB Inlet Air Temp
Fluid Bed Inlet Temp
Abs humidity
Feed solids
Dryer Exhaust RH
Solids throughput
Product Moisture
Air flows
Dryer
Controller
12. 12
Spray Dryer application drying Cheese Whey
• Feed : 8000 Kg/Hr. processing with 9% final moisture
• 3760 Kg/Hr. solids
• Change in operational setpoints with use of Advance
automation
• Revised Final Moisture: 10%
• 1% increase in moisture due to better multivariable control
• 1% increase translates to 46 Kg/Hr. additional product (as
water)
• Assume dryer operation at 288 days/year, 24 hours/day
• ~6900 hours/year
• Total increase in production: 317 Tons/year
• Value of Increase: 250 – 317 Tons/year
13. 13
Commercial Benefits
• Key is price of product: $1.20 - $1.50/Kg…..or higher!!
• NFDM
• Cheese Whey
• Lactose
• WPC Powder
• Automation Sell Price: $300 - $400K
• Moisture Analyzers
• Software and associated APIs
• Design/Engineering
• Remote Support (optional)
• Payback: 9 - 15 months
This can be an eye opener if you really crave for energy in your
country.
14. 14
Where the Technology stands today & how it works
More than 30 similar advanced control projects
have either been put in place or are in the
process of being installed in milk powder,
casein and cheese plants.
The technology permits operators to accurately
control factors that alter milk's quality and
consistency during the evaporating and drying
cycles.
Using models obtained from process data
allows to predict the future performance of the
plant, enabling correction before external
factors come through and affect the operation.
Process
15. 15
Additional benefits to the dairy which cannot
be quantified
• Improvement in powder Quality by precisely controlling
moisture & bulk density of milk powder.
• Reduction in stack loss & improvement in environment.
• Reducing energy consumption by adaptive controls ( 3 to
10% savings)
• Quicker, more effective start - up.
• Reduces wastages & reworking by stopping choke-ups &
plant shutdowns.
• Improves thermal efficiency.
• Improves safety of plant
• Reduces fouling will reduce frequent requirement of CIP
• MIS, ERP & Energy management
18. 18
Upstream Cheese
Supply
Controlled Variable
Manipulated Variable
Measured (known) Variable
KEY:
Temperature
Water Content
Water
Steam Pressure
Weight
Moisture
Recipe
Valve Position
Temperature
To Downstream
Processing
Additives
Weight
Moisture
Water Quantity
Generic Cheese Cooker Diagram
19. 19
Control Objectives
Control temperature in batch cookers
Achieve consistent product temperature profiles and batch times
Achieve consistent steam condensation in cookers
Achieve consistent, closer to target, final product temperature
Control product moisture
Achieve tighter and consistent control of downstream line moisture
Make model based adjustments between moisture lab samples
Consistent water addition adjustments per downstream line feedback
Temperature and moisture
Enable maximum possible line throughput
Enable maximum possible moisture content
20. 20
Business Objectives
OBJECTIVES ACTUAL RESULTS
Line throughput increase 7.6%
Yield increase 0.15% (based on moisture content only **)
Steam usage reduction 7.7% (less energy used)
Batch time reduction 13.5% (less time per batch)
Temperature variation reduction 40%
Operational benefits consistent control adjustments
consistent cheese quality
** Additional yield increase possible due to scrap/rework reduction
21. 21
Key Features of Temperature Control
Modeling
Dynamic heat/mass cooker model was developed and used to design, test
and evaluate control algorithms
Batch cycle temperature control
Constraint control (control final temperature to a minimum)
Control to multiple set points during different phases of cooker batch
Timing (follow batch logic to quickly satisfy conditions for next steps)
Expert (use expert set starting values for optimal initial conditions)
PID (instruction used for fast feedback corrections)
Steam valve manipulation (manipulated variable, actuator)
Controller tunable per recipe
Controller integrated in CLX/PLC, reusable code
Bumpless controller switching ON/OFF
22. 22
Key Features of Moisture Control
Modeling
Based on upstream sampling per cooker load
Mathematical model used for real time calculations
Controls
Model based compensation for upstream variation
Operator adjustments available (if needed)
Downstream line adjustments
Operator input: Set point (target) for product moisture
Output: water addition correction
Tunable magnitude of adjustments
Controller integrated in CLX/PLC, reusable code
Bumpless switching ON/OFF
23. 23
Final Product Temperature Before-After
Reduction of average final temperature and reduction of final temperature variation contribute to
downstream faster processing.
BEFORE AFTER IMPROVEMENT
AVERAGE minus MINIMUM 2 deg F 1.4 deg F 30%
STANDARD DEVIATION 1.4 deg F 0.7 deg F 50%
24. 24
Steam Consumption Before-After
Average Steam Consumption Reduction: 7.7%
Equivalent of: 68 PSIhours/day
DEC 04 = BASELINE
PSImin
Cooker #1: BLUE
Cooker #2: RED
Average: YELLOW
25. 25
Batch Time Before-After
Batch time improvements, RECIPE 1:
Batch time BEFORE: 255 seconds
Cooker #1 AFTER: 217 seconds
Cooker #2 AFTER: 228 seconds
Batch time improvements, RECIPE 2:
Batch time BEFORE: 200 seconds
Cooker #1 AFTER: 188 seconds
Cooker #2 AFTER: 188 seconds
26. 26
Moisture Control Before-After
Before After
Tests
Approximately 10-15% variation reduction, improved controllability.
Enabled moving the target to economically more favorable setting.
Target
30. 30
Slurry Solids/Water Balance Control Application
Capabilities
– 50% reduction in slurry
solids/pH variability
– Continuous management
of fermentation gap
increasing capacity and
stabilizing plant to milling
target
– Stabilize mineral/backset
conditions to fermentation
– Manage process water
toward global
requirements/make-up
Benefits
– Increase ethanol yield (~2%
gal/bu)
– Increase fermentation capacity
(MMGPY)
– Increase enzyme effect
(enzyme/gal)
8 8
Methanator
Slurry Tank
Process Water
Liquefaction
Backset
Beer Feed
Milling
88 88
MethanatorMethanator
Slurry Tank
Process Water
Liquefaction
Backset
Beer Feed
Milling
31. 31
Fermentation Control Application
Capabilities
– 50% reduction in batch EtOH and
dextrose/residual sugars variability
– Continuously manage enzymes to
maximize throughput and ethanol
yields
– Optimal target on temperature and
pH for fermentation
– Manage fermentations to match
production targets
Benefits
– Increase in batch drop ethanol yield
(MMGPY) by 0.5-1.0%
– Increase in fermentation capacity by 5-
12% (MMGPY)
– Increase in batch yields (gal/bu) by 2-5%
– Reduce enzymes/gal ($$ enzymes/gal) by
5-10%8
Slurry Tank
Liquefaction
Backset
Beer Feed
Fermenter
Yeast Propagation
Enzymes
88
Slurry Tank
Liquefaction
Backset
Beer Feed
Fermenter
Yeast Propagation
Enzymes
32. 32
Beer Feed
Evap. Steam
Steam Flow
Sieve Back
Pressure
Rectifier Reflux Sieve Feed
Vaporizer Temperature
Beer Feed
Evap. Steam
Steam Flow
Sieve Back
Pressure
Rectifier Reflux Sieve Feed
Vaporizer Temperature
Distillation / Molecular Sieve Application
Capabilities
– Integrate non-linear models,
multivariable control and advanced
optimization in one algorithm
– Control distillation to optimum
moisture
– Control end-product moisture to the
desired specifications
Benefits
– Increase Ethanol production
capacity 3-10%
– Increase ethanol yield by .1-.2%
– Reduce energy use/gallon by 1-2%
33. 33
Dryer Control Application
Capabilities
– Direct targeted control of Syrup Solids and
DDGS moisture
– Continuous management of dryer capacity
(centrifuge feed) against dryer operating
limits (moisture, temperature, gas)
– Balance dehydration energy between
evaporation and drying
– Reduce Overdrying, stabilize dryer and
reduce energy consumption/ton
– Stabilize plant steam and thermal oxidizer
thermal destruction temperature against
operating limits
Benefits
– Increase average DDG yield of 1-1.5%
– Reduce energy costs per gallon of
ethanol produced by 2-4%
– Reduce product moisture variability
by more than 50%
Steam Flow
Centrifuge Feed
Whole Stillage
Thin Stillage
Syrup Tank
Wet Cake
Pad
Steam Flow
Centrifuge Feed
Whole Stillage
Thin Stillage
Syrup Tank
Wet Cake
Pad
35. 35
APC Project Flow
Enhance Profitability
– Increase Production
• Unlock capacity
• Maximize throughput
– Reduce Manufacturing Costs
• Use less energy per unit of output
• Maximize alternative fuels use
– Improve Product Quality
• Minimize variability
• Reduce deviation from
specifications
– Reduce Environmental Risk
• Achieve active emissions
compliance
• Support emissions trading
