mpc for sugar processing

8/11/2019 MPC for Sugar Processing

1/30

Sugar Processing MPC

Copyright 2011 Rockwell Automation, Inc. All rights reserved.

Zilor.

Plant MPC Milling

Juice Treatment Evaporation

Crystallization

Boilers/Steam Turbines


2/30

Delivering Value to Market Leaders

Chemicals / Polymers CementBiofuels

Copyright 2011 Rockwell Automation, Inc. All rights reserved. 2

Minerals & Metals

Consumer Goods


3/30

Pavilion MPC Best Practice for Ethanol Production


4/30

What we do

Minimize operational variance

DV CV

Transition effectively

Experienced Referenced SuccessfulLeverage Our Technology and People to

deliver highest value through ValueFirst


CV

Follow operational plan

CV

SPECIFICATION OR LIMIT

BEFORE MODEL

PREDICTIVE CONTROLWITH MODEL PREDICTIVE CONTROL

AND OPTIMIZATION

TIME

KEY

TARGET


5/30


6/30

Model Based

Incorporates Physical and Neural Models

Handles Linear and Non-Linear

Models are Fully Differentiable

Same Models Used for Control and Optimization

Import Existing Models

NN

Phys

u + y

FP error

Physical


output (y)

y = a1 x + a0

input (x)

input (x)

output (y)

y = a3x3+ a2x

2

+ a1 x + a0

Linear

Non-Linear

Artificial Neural Network


7/30

What We Do MPC Control

MV set point

MV measured value

MV predictionUse first step of horizon

Manipulated Variable (MV)


CV prediction

CV measured valueMPC optimizes future trajectoriesusing an internal simulation

CV desired valuecurrent time indicator

Controlled Variable (CV)


8/30

The question is not just how much the process will move,

but how fastthe change will occur.

1CV

Multivariate Dynamic Coordination


1 2MV Air Temperature

2CV

MV High Pressure Pump

By understanding this MPC can be used to

coordinate and enable the process to respond faster.


9/30

ClO2 Generation Solution

Pavilion8TM

Control Strategy



10/30

Plant Assessment

Mill Discussions 10/19-20, Mill testing 10/21, 24

Sugars Discussions 10/21, 24, Sugar testing 10/24-25

Utilities Discussions 10/25

Meeting Prep 10/26


, , , , ,

P&IDs

Data PIMS

Data Lab

Data Historian

Step Test Data


11/30

Plant Tests

Mill Test on Extraction Water Temperature: increasing water

temperature increases bagasse sugar.

Mill Test Mud Flow % (Sugar Clarifier): decreasing mud flow

increases mud Baume, but does not impact clarified juicetransmittance significantly.

Juice to Sulfidation Temperature: decreasing this temperature


increases sulfur, reduces time to stabilization and we need tocompare evaporator brix (unknown currently)

Sulfur Motor Speed test: not complete. Desired to decrease sulfur

5% each motor, increase up to 10% (as possible in burner) and

decrease back 5% for 2 hours and measure sulfur, sulfur juice pH,time to stabilization into clarifier.


12/30

Mill Control



13/30

Mill Anticipated MPC Solution

The Mill MPC solution manages Table Speed(s), Mill Pressure, Superior Roll

speed and water flow in response to Bagasse Moisture, Sugar and Juice Brix

quality estimation models. From typical variability five-roller mills in series, MPC

would deliver benefits: Reduce Bagasse Moisture and Juice Brix Variability 30-70%.

Increase capacity through mill responding to variation in cane quality and table,

picador amps


ncrease s a ze agasse sugars


14/30

Mills (54 & 78) Anticipated MPC Scope

Uncontrolled Influences

(Disturbance Variables)

Mill 78Table Speed (2)

Mill 1 Infeed Level

Fiber in CaneHours since BurnWater to Mills Temperature

TPH Estimate (VOA)

Conveyer Level (operator input bias, VOA)

Bagasse Moisture (VOA)

Process Setpoints(Manipulated Variables)

Process Results(Controlled Variables)

Table Amps (limit)

Picador Amps (limit)

Superior Roll Speed RPM (6)Mill Pressure (6)

Water Flow

Mill Positioner (10, limit)


15/30

Juice Treatment and Evaporation Control



16/30

Juice Treatment & Evaporation MPC Solution

The Juice & Evaporation MPC solution manages juice rates, temperature, S motors, mud flow

ratios and evaporator balance in response to settling times, residual chemical, color and

evaporator brix quality estimation models along with steam availability. From typical variability

carbonation/sulfidation MPC would deliver benefits on the order of:

Reduce Sulfur/Lime addition based on variation on residual chemical numbers. Reduce clarified Juice color variability. This provides more stable crystallization and average

color reduction.

Increase sugar/syrup to crystallization by maximizing energy usage as available. Reduce filter

su ar losses. Review unidentified losses in data.


Box to


17/30

Juice Treatment & EvaporationMPC Scope



Sugars

Vacuum Filter Flow to Sugars Treatment

Secondary Juice to Primary Juice or back (2)

Steam FlowPrimary Juice Purity

Vegetal numbers on Cane

Clarified Juice Transmittance

Stabilization time into clarifier

Sulfito before Lime Addition

Total Juice to Clarifier Flow

Anticipated


Process Setpoints(Manipulated Variables) Process Results

(Controlled Variables)

Syrup Tank Level, Clarification Tank Level

Evaporator Brix (4)

Evaporator Vacuum (4, limit)

empera ure o u a on

Sulfur Motor Speed (4)

Mud Flow Ratio (2)

Flow to Evaporators (1, 4)

Mud Baume (2)

Exhaust Steam Pressure (limit)


18/30

Juice Treatment & Evaporation Instruments

Priorities for improvements and recommendations are (sulfidation):1. Add TI on gas from the cooler (entering the column with SO2).

2. Add FI on flow to each sulfidation column (check pipe L/D).

3. Change hand valve on CW to automated, controlled valve and close loop withgas temperature.

4. Ratio loop flow to each column and sulfur mechanical motor speed.

5. Add TI on gas from each column (and use this to manually balance motors, balance


.

Priorities for improvements and recommendations are (clarification,

vacuum filters, Water Supply and Pans): Electronically store time-stamp and results on operator Mud Baume (4) and

Stabilization Time (2). Bias various vacuum filter amps based on earlier study recommendations. Review Control on Aspersor (spray pond) water tank level (for multi-jet). Move density analyzer on Diluted Molasses A density to tank instead of line.

Continue to control density with dilution condensate (with slower dynamics).


19/30

Pavilion8 Solutions Evaporation



20/30

Crystallization Control (Pans, 11)



21/30

Batch Crystallization Anticipated MPC Solution

The crystallization MPC solution manages pan operations across the batch crystallization pans to

stabilize supersaturation point, manage crystallizers toward a more ideal trajectory and

balance consistency and supersaturation along with level objectives to:

Increase crystallization capacity (through maximal operation in stable supersaturation regions,

maximizing end of strike consistency. Reduce variability on crystal size both through reduction in conglomerates and minimizing or

eliminating time in liable crystallization regions (e.g. maximize sugar kg/pan and sugar kg/pan

kg steam).

Through maximum strike effectiveness the solution will reduce time at high temperatures


during crystallization (reducing extra batching of sugar) and increasing sugar yields slightly(e.g. reduced molasses B sugars).

/


22/30

Batch Crystallization Anticipated MPC Scope



BatchCrystallization

Brix Tg or Feed VP

Syrup or A Mel Brix, Purity

Supersaturation (VOA/Calc)

Consistency (VOA/Calc, limit)


Process Setpoints

(Manipulated Variables)Process Results


Controller Level (limit)on enser ressure

Condenser VP (limit)Steam Valve pos

Control batch crystallizers to target supersaturation within

limits. Include models covering white/sucrose

high raw (A) and low raw (B) crystallization.


23/30


Use temperature, start and

approximated purity tocalculate Supersat real-time


Qsat at 70 DegC Qsat at 99% Purity


24/30


Use temperature, start and

approximated purity tocalculate Supersat real-time


Qsat at 85 DegC Qsat at 70% Purity


25/30

Utilities/Bagasse Boiler and Steam Control



26/30

Utilities/Bagasse Boiler and Steam MPC

Steam Generation Optimization to manage bagasse boilers loads,

turbine loads, let-down PRVs to manage steam pressure and exhaust

steam availability along with maximizing turbine MW.

Maximize boiler efficiency with improved coordinated boiler MPC tomanage bagasse boilers with feed/O2 within safety and environmental

limits at maximum capacity.



27/30

Steam/Bagasse Boiler Anticipated MPC Scope



Steam Flow CBC and AMD TG


Process Setpoints

(Manipulated Variables)

Process Results


Steam Header

Controller

CBC and AMD Pres

CBC and AMD O2

Turbine load (4)

Steam Temperature (2, limit)

MW Produced (TG)

Steam Pressure (21 & 1.8, TG)

PRV Control (6) Exhaust Steam Condenser VL (TG)

Relief VL (3)


28/30

Fisher Provox Operator Interface


29/30

Next Steps:

First portion assessment 12/2 or 12/5

Complete assessment 1/5 or 1/7


Assessment will include

Data Analysis

Benefits Assessment

Solution Description (update) Costs and time estimate for delivery


30/30

Questions ?


mpc for sugar processing

Documents