AE 503 TERM PROJECTAE 503 TERM PROJECTTRACKING THE PURITY OF NON-GM TRACKING THE PURITY OF NON-GM

GRAIN AT THE LOCAL ELEVATOR USING GRAIN AT THE LOCAL ELEVATOR USING DYNAMIC MODELLINGDYNAMIC MODELLING

Maureen SuryaatmadjaMaureen SuryaatmadjaGraduate Research AssistantGraduate Research Assistant

Agricultural EngineeringAgricultural EngineeringIowa State UniversityIowa State University

April 29, 2005April 29, 2005

IntroductionIntroduction

Traceability is the ability to trace the Traceability is the ability to trace the history, application or location of an history, application or location of an entity by means of recorded entity by means of recorded identifications identifications

(Hurburgh, 2004)(Hurburgh, 2004) Traceability has become a major Traceability has become a major

concern for food manufacturers and concern for food manufacturers and commodity handlerscommodity handlers

IntroductionIntroduction

The issue of GMO has been closely The issue of GMO has been closely associated with traceability. In reality, associated with traceability. In reality, product tracking serves much wider such as:product tracking serves much wider such as:

1.1. To document a chain of custody of a product.To document a chain of custody of a product.

2.2. To document how a product was produced or handled.To document how a product was produced or handled.

3.3. To meet consumer desire for connection with the earth To meet consumer desire for connection with the earth and production and the environment and/or some other and production and the environment and/or some other socio-religious need.socio-religious need.

4.4. To provide due diligence for buyer safety/quality To provide due diligence for buyer safety/quality assuranceassurance

5.5. To respond to the security needs or regulations.To respond to the security needs or regulations.

(Hurburgh, 2004)(Hurburgh, 2004)

Problem StatementProblem Statement

The bulk grain production and marketing The bulk grain production and marketing system has not been considered adaptable system has not been considered adaptable to identity tracking, but there have been to identity tracking, but there have been programs to produce special grains for programs to produce special grains for individual users that require some form of individual users that require some form of purity maintenance.purity maintenance.

More recently, EU customers had begun More recently, EU customers had begun asking for assurances that certain GM asking for assurances that certain GM materials were kept out of commodity materials were kept out of commodity grain, to an 0.9% or less mixing level.grain, to an 0.9% or less mixing level.

Flow ChartFlow Chart

Grain Flow ChartGrain Flow Chart

Production Farm SalesLocal

ElevatorsGrain

ProcessorFood andIndustry

TruckPit and

ConveyorBucket

ElevatorsBin

(storage)

Local Elevator Flow Chart

Problem StatementProblem Statement

The key areas in an elevator that provide The key areas in an elevator that provide challenges for Identity Preservation (IP):challenges for Identity Preservation (IP): Receiving pitsReceiving pits ConveyorsConveyors LegsLegs Storage BinsStorage Bins

(Thelen, 1999)(Thelen, 1999) This project will analyze the mixing This project will analyze the mixing

process in the pit and conveyor, and process in the pit and conveyor, and bucket elevator (legs)bucket elevator (legs)

ObjectiveObjective

To build a dynamic simulation model To build a dynamic simulation model that tracks the grain purity at the that tracks the grain purity at the local elevator with the respect to the local elevator with the respect to the purity of non-GM grain from GM grain purity of non-GM grain from GM grain contamination.contamination.

AssumptionsAssumptions The grain is checked for the initial The grain is checked for the initial

purity before it unloads from the purity before it unloads from the truck (GM/non-GM grain).truck (GM/non-GM grain).

The system only use one pit.The system only use one pit. There will be no cleaning activity in There will be no cleaning activity in

the pit, conveyor and bucket elevator.the pit, conveyor and bucket elevator. There will be some grain left in the pit There will be some grain left in the pit

and the bucket.and the bucket. The process is perfect mixing.The process is perfect mixing.

AssumptionsAssumptions

The final purity is the grain purity The final purity is the grain purity after exiting the bucket.after exiting the bucket.

After exiting the bucket elevator, the After exiting the bucket elevator, the non-GM grain will be stored at non non-GM grain will be stored at non GM bin and the GM grain will be GM bin and the GM grain will be stored at GM bin. stored at GM bin.

Differential Equations DevelopmentDifferential Equations Development

Mass balance equation:Mass balance equation:

dM/dt = qin – qout dM/dt = qin – qout (1)(1)

M = accumulated mass of M = accumulated mass of

the grain (kg)the grain (kg) dM/dt = mass flow rate of dM/dt = mass flow rate of

the grain (kg/s)the grain (kg/s) qin = grain flow rate entering qin = grain flow rate entering

the tank (kg/s)the tank (kg/s) qout = grain flow rate exiting qout = grain flow rate exiting

the tank (kg/s)the tank (kg/s)

Differential Equations DevelopmentDifferential Equations Development Mass balance of the contaminant: Mass balance of the contaminant: dmc/dt = qin Cin – qout Cout (2)dmc/dt = qin Cin – qout Cout (2)

Cout = mc/M (dimensionless) (3)Cout = mc/M (dimensionless) (3)

Equation (3) is divided by M becomeEquation (3) is divided by M become::

dCout/dt = 1/M (qin Cin – qout Cout) (4)dCout/dt = 1/M (qin Cin – qout Cout) (4) mc = mass of the contaminant grain (kg)mc = mass of the contaminant grain (kg) dmc/dt = mass flow rate of the contaminant grain (kg/s)dmc/dt = mass flow rate of the contaminant grain (kg/s) qin = grain flow rate entering the tank (kg/s)qin = grain flow rate entering the tank (kg/s) qout = grain flow rate exiting the tank (kg/s)qout = grain flow rate exiting the tank (kg/s) C in = grain concentration entering the tank (%)C in = grain concentration entering the tank (%) C out = grain concentration exiting the tank (%)C out = grain concentration exiting the tank (%)

Differential equation application of Differential equation application of grain mixing process in the local grain mixing process in the local elevatorelevator At the pit and conveyorAt the pit and conveyordMpit/dt = qpiti - qpitedMpit/dt = qpiti - qpite (5) (5)

dCconve /dt = 1/(dMpit/dt) (qconvi Cconvi - qconve Cconve) dCconve /dt = 1/(dMpit/dt) (qconvi Cconvi - qconve Cconve) (6)(6)

dMpit/dt = the grain mass rate of change of left in the pitdMpit/dt = the grain mass rate of change of left in the pitdCconve/dt = the grain purity rate of change exiting the dCconve/dt = the grain purity rate of change exiting the

conveyorconveyorqpiti = grain flow rate entering the pitqpiti = grain flow rate entering the pitqpite = grain flow rate exiting the pitqpite = grain flow rate exiting the pitCconvi = the purity of grain entering the pit and conveyor Cconvi = the purity of grain entering the pit and conveyor

(initial purity of grain)(initial purity of grain)Cconve = the purity of grain exiting the conveyorCconve = the purity of grain exiting the conveyorq truck out = q pit inq truck out = q pit inq pit out = q conveyor in = q conveyor outq pit out = q conveyor in = q conveyor out

Differential equation application of Differential equation application of grain mixing process in the local grain mixing process in the local elevatorelevator At the bucket elevatorAt the bucket elevatordMbucket/dt = qbucketi - qbuckete (7) dMbucket/dt = qbucketi - qbuckete (7)

dCbuckete/dt = 1/(dMbucket/dt) (qbucketi Cbucketi - qe Cbuckete) dCbuckete/dt = 1/(dMbucket/dt) (qbucketi Cbucketi - qe Cbuckete)

(8) (8) dM/dt = the grain mass rate of change in the bucket dM/dt = the grain mass rate of change in the bucket dCbuckete /dt = the grain purity rate of change exiting the bucketdCbuckete /dt = the grain purity rate of change exiting the bucketqbucketi = grain flow rate entering the bucket elevatorqbucketi = grain flow rate entering the bucket elevatorqbuckete = grain flow rate exiting the bucket elevatorqbuckete = grain flow rate exiting the bucket elevatorCbucketi = the purity of grain entering the bucket elevatorCbucketi = the purity of grain entering the bucket elevatorCbuckete = the purity of grain exiting the bucket elevator (final Cbuckete = the purity of grain exiting the bucket elevator (final

purity of grain)purity of grain)q conveyor out = q bucket inq conveyor out = q bucket inCbucketin = CconveCbucketin = Cconve

Simulink ModelSimulink Model The simulink model consist of four subsystems:The simulink model consist of four subsystems:

1.1. The first subsystem describes the changing of the The first subsystem describes the changing of the grain mass in the pit grain mass in the pit

dMpit/dt = qpiti - qpite , qpit e = A (Mpit –C)dMpit/dt = qpiti - qpite , qpit e = A (Mpit –C)2. The second subsystem describes the changing of 2. The second subsystem describes the changing of

the grain purity after exiting the conveyor the grain purity after exiting the conveyor dCconve /dt = 1/(dMpit/dt) (qconvi Cconvi - qconve dCconve /dt = 1/(dMpit/dt) (qconvi Cconvi - qconve

Cconve)Cconve)3. The third subsystem describes the changing of the 3. The third subsystem describes the changing of the

grain mass in the bucket grain mass in the bucket dMbucket/dt = qbucketi – qbucketedMbucket/dt = qbucketi – qbuckete4.4. The fourth subsystem describes the changing of the The fourth subsystem describes the changing of the

grain purity after exiting the bucket elevatorgrain purity after exiting the bucket elevator dCbuckete/dt = 1/(dMbucket/dt) (qbucketi Cbucketi dCbuckete/dt = 1/(dMbucket/dt) (qbucketi Cbucketi

- qe Cbuckete)- qe Cbuckete)

Qpit in=Qtruckoutmpit

C conv out

Q conv out

C conv in

Q conv in

Cbucket in

mbucketQ bucket in

Q bucket out

C bucket outQ bucket out

Q pit out

Qbucket in

1s

simout

To Workspace

Switch1

Switch

Step1

Step

Scope4

Scope3

Scope2

Scope1Product

1s

1s

1s

Integrator

-K-

1.5

-C-

Current Load purity

07

0

0.5

1

u1/mpit

1

u1/mbucket

MATLAB INPUTMATLAB INPUTclose all % Close all open figuresclose all % Close all open figuresclear all % Clears all the variables in the workspaceclear all % Clears all the variables in the workspaceCon = [0 100 0 100 ]; Con = [0 100 0 100 ]; simsave = [];simsave = [];for load = 1:4for load = 1:4disp(load);disp(load);currentloadpurity = Con(load);currentloadpurity = Con(load); if load == 1if load == 1 mpit = 0.0001;mpit = 0.0001; cpit = 0;cpit = 0; mbucket = 0.0001;mbucket = 0.0001; cbucket = 0;cbucket = 0; elseelse mpit = simout.signals.values(size(simout.signals.values,1),1);mpit = simout.signals.values(size(simout.signals.values,1),1); cpit = simout.signals.values(size(simout.signals.values,1),2);cpit = simout.signals.values(size(simout.signals.values,1),2); mbucket = simout.signals.values(size(simout.signals.values,1),3);mbucket = simout.signals.values(size(simout.signals.values,1),3); cbucket = simout.signals.values(size(simout.signals.values,1),4);cbucket = simout.signals.values(size(simout.signals.values,1),4); endend[T,X,Y]= sim('impurity',[0 8000]); [T,X,Y]= sim('impurity',[0 8000]); disp(simout.signals.values(size(simout.signals.values,1),1:4));disp(simout.signals.values(size(simout.signals.values,1),1:4));simsave = [simsave; simout.signals.values];simsave = [simsave; simout.signals.values];endend

Input ValueInput Value First StepFirst Step step time = 12.5step time = 12.5 initial value = 0initial value = 0 final value = 17.5final value = 17.5 sample time = 0sample time = 0 Second StepSecond Step step time = 367.5step time = 367.5 initial value = 0initial value = 0 final value = -17.5final value = -17.5 sample time = 0sample time = 0

Input ValueInput Value Mpit initial before the first load flow = 0.0001 kgMpit initial before the first load flow = 0.0001 kg Cpit initial before the first load flow = 0Cpit initial before the first load flow = 0 Mbucket initial before the first load flow = 0.0001 kgMbucket initial before the first load flow = 0.0001 kg Cbucket initial before the first load flow = 0Cbucket initial before the first load flow = 0 Switch function in the pit: qpite = A(Mpit – C)Switch function in the pit: qpite = A(Mpit – C) A = 0.001A = 0.001 C = 0.5 C = 0.5 Treshold = 7, 15Treshold = 7, 15 Switch function in the bucket elevator: qbuckete = A(Mbucket – Switch function in the bucket elevator: qbuckete = A(Mbucket –

C)C) A = 1.5A = 1.5 C = 7, 15 C = 7, 15 Treshold =7,15Treshold =7,15 T = 8000 sT = 8000 s

Result Result

First Combination Load:First Combination Load:1.1. GM load = 0% non-GM loadGM load = 0% non-GM load

2.2. Non-GM load = 100% non-GM loadNon-GM load = 100% non-GM load

3.3. GM load = 0% non-GM loadGM load = 0% non-GM load

4.4. Non-GM load = 100% non-GM loadNon-GM load = 100% non-GM load

ResultResult

LoadLoadInitialInitialPurityPurity M grain left inM grain left in C exiting C exiting M grain left inM grain left in C exiting C exiting

   (%)(%)

the pit the pit

(kg)(kg)

conveyor conveyor

(%)(%)

the bucketthe bucket

(kg)(kg)

BucketBucket

(%)(%)

11 00 7.00007.0000 0.00000.0000 7.00187.0018 0.00000.0000

22 100100 7.00007.0000 99.906299.9062 7.00037.0003 99.689099.6890

33 00 7.00007.0000 0.09370.0937 7.00257.0025 0.18730.1873

44 100100 7.00007.0000 99.906399.9063 7.00047.0004 99.690499.6904

ResultResult

LoadLoadInitial Initial

PurityPurity M grain left inM grain left in C exiting C exiting M grain left inM grain left in C exiting C exiting

   (%)(%)

the pitthe pit

(kg)(kg)

ConveyorConveyor

(%)(%)

the bucket the bucket

(kg)(kg)

BucketBucket

(%)(%)

11 00 15.000015.0000 0.00000.0000 15.017615.0176 0.00000.0000

22 100100 15.000015.0000 99.799399.7993 15.001015.0010 99.474599.4745

33 00 15.000015.0000 0.20030.2003 15.000715.0007 0.40030.4003

44 100100 15.000015.0000 99.799799.7997 15.000815.0008 99.474299.4742

ResultResult

The second combination load:The second combination load:1.1. GM load = 0% non-GM loadGM load = 0% non-GM load

2.2. GM load = 0% non-GM loadGM load = 0% non-GM load

3.3. Non-GM load = 100% non-GM loadNon-GM load = 100% non-GM load

ResultResult

LoadLoadInitial Initial

PurityPurity M grain left inM grain left in C exiting C exiting M grain left inM grain left in C exiting C exiting

   (%)(%)

the pit the pit

(kg)(kg)

ConveyorConveyor

(%)(%)

the bucketthe bucket

(kg)(kg)

BucketBucket

(%)(%)

11 00 7.00007.0000 0.00000.0000 7.00187.0018 0.00000.0000

22 00 7.00007.0000 0.00000.0000 7.00437.0043 0.00000.0000

33 100100 7.00007.0000 99.906299.9062 7.00157.0015 99.706099.7060

ResultResultThe Changing of Grain Purity After Exiting Bucket

0

20

40

60

80

100

120

1 1144 2287 3430 4573 5716 6859 8002 9145 10288 11431 12574 13717 14860

Time (s)

Pu

rity

(%

)

ResultResult

0 500 1000 1500 2000 2500 3000 3500 40000

1000

2000

3000

4000

5000

6000

Time (s)

Gra

in M

as

s (

kg

)

The Changing Mass in the Pit

ResultResult

0 500 1000 1500 2000 2500 3000 3500 40000

10

20

30

40

50

60

70

80

90

100

Time (s)

Purity

(%

)

The Changing Grain Purity After Exiting The Conveyor

ResultResult

0 500 1000 1500 2000 2500 3000 3500 40006.5

7

7.5

8

8.5

9

9.5

10

10.5

Time (s)

Gra

in M

as

s (

kg

)

The Changing Mass in the Bucket

ResultResult

0 500 1000 1500 2000 2500 3000 3500 40000

10

20

30

40

50

60

70

80

90

100

Time (s)

Gra

in P

uri

ty (

%)

The Changing Grain Purity After Exiting The Bucket

ConclusionConclusion The model is not able to describe all the processes The model is not able to describe all the processes

that happen in the local elevator; however it can that happen in the local elevator; however it can be used to track the purity of the grain.be used to track the purity of the grain.

The final purity level depends on the amount of The final purity level depends on the amount of grain that left in the pit and the bucket.grain that left in the pit and the bucket.

When the amount of grain left in the pit and the When the amount of grain left in the pit and the bucket increase, the final purity level will bucket increase, the final purity level will decrease.decrease.

It is important to keep grain left in the pit and It is important to keep grain left in the pit and bucket as least as possible.bucket as least as possible.

The future development should improve the The future development should improve the accuracy of the model and describe all the accuracy of the model and describe all the processes happen in the local elevator.processes happen in the local elevator.

SPECIAL THANKS TO:SPECIAL THANKS TO:

DR. BRIAN STEWARD for his DR. BRIAN STEWARD for his valuable advises and helps in valuable advises and helps in

developing the simulation modeldeveloping the simulation model