NAQM - 06 OCT 05
OBTAINING SAMPLES FOR TESTING (PLANT)
SAFETY NOTES
Precautions should be taken when handling ethanol, sulfamic acid, and caustic. Refer
to MSDS for further information on handling these chemicals.
SCOPE
This method describes the sampling procedures used for obtaining samples for process
testing. It also indicates the priority of each individual test.
QUALIFICATIONS
The employee obtaining samples must read through the procedures indicated in this
method before obtaining process samples. This is to ensure consistency in obtaining
the samples as well as increase the consistency of results obtained following testing.
The employee should be familiar with the chemicals being tested (caustic, sulfamic
acid, and ethanol) as well as any pertinent MSDS information regarding accidental
spillage or personal contamination.
PERFORMING THE TASK
Procedures for these tests will be made available for reference.
*** Priority Testing
** Secondary Priority Testing
* Not such a priority at this time, as we get operational and operators get
comfortable, these will become more of a priority.
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NAQM - 06 OCT 05
OBTAINING SAMPLES FOR TESTING
***Acidity of Fuel Ethanol
Sample should be taken approximately once every 1-2 hours and before the filled shift
tank is transferred to the marketing tank to ensure the process is being done properly.
This should be done concurrently with the sample procedure for Apparent Proof (see
below). Obtain enough sample to perform procedure and if needed perform an
additional procedure to verify results. This volume should be approximately 60mL.
The test requires 50mL of ethanol. If resample is needed, obtain another 60mL
sample. Obtain sample in sealable container to prevent environmental contamination.
Perform analysis in accordance to Lab Procedure 01 – Acidity of Fuel Ethanol.
Acidity should not be less than 0.006 and should not change by more than 20%.
Record results, time, date and initial on appropriate NAJA form and place in
appropriate log book.
If sample results are greater than 0.006 re test sample, and if still above specifications
inform lead operator, and discuss with lead operator a containment strategy.
***Apparent Proof
Obtain a sample from the 190 and 200 proof shift tanks every 1-2 hours. The sample
taken from the 200 proof tank will be tested in concurrence with the sample for acidity
where the 190 proof sample will only be tested for strength. Testing the 190 proof
tank ensures that the alcohol being transferred to the molecular sieves is not too wet.
The volumes for these samples should be enough to fill the hydrometer cylinder
approximately 2 inches from the top. Perform test procedure in accordance to
Laboratory Procedure 03 – Apparent Proof.
Apparent Proof must be maintained between 200 and 203 for the product after it has
been cycled through the molecular sieve. 190 proof ethanol must be no less than 188
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NAQM - 06 OCT 05
OBTAINING SAMPLES FOR TESTING
proof before it can get transferred to the molecular sieve. If results are outside these
parameters, retest sample, and if results do not meet specified results, inform lead
operator, and discuss with lead operator a reaction strategy.
*** Brix Test
When obtaining samples, ensure you have enough time to perform the test as the age
of the sample directly affects the results you will obtain. For accurate results test the
samples as soon as possible.
Calibration of Refractometer should be completed before each sample. This takes
very little time and ensures you are getting accurate results from the refractometer.
Samples should be taken from fermentation tanks at regular intervals up till the time
of tank dumping. Initial sample should be taken approximately __4__ hours into start
of fermentation. Over the fermentation cycle samples should be taken at 12 hours, 22
hours 34 hours, 48 hours and at end of fermentation cycle. Sample times should be
taken in accordance to operator experience. If the fermentation is taking longer than
anticipated, judge accordingly.
Obtain duplicate samples and place in appropriately sized containers (weights should
be in equal volume to ensure proper centrifugation). Only perform the Brix test on
one sample, but treat the samples as if they were both being tested to ensure proper
balance of the centrifuge.
Perform Brix test in accordance to Laboratory Procedure 04 – Brix Reading
Results should steadily be decreasing throughout the fermentation process while
alcohol content should be steadily increasing. If this is not the case, retest sample, and
if results do not meet specified results, inform lead operator, and discuss with lead
operator a reaction strategy.
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OBTAINING SAMPLES FOR TESTING
Record calibration (yes/no), results, time, date and initial on NAJA and place in
appropriate log book.
**Caustic Strength
This method should be completed before every CIP operation to ensure caustic
strength is appropriate concentration.
Obtain a sample of CIP solution from the CIP holding tank when it has been
theoretically mixed to appropriate concentration. This sample does not need to be
very large, but large enough to perform the test twice if required. Procedural outline
requires 1.0 gram of sample per test.
Perform procedure in accordance to Laboratory Procedure – 05 – Caustic Strength
Target range is between 4-5 percent caustic strength, if outside specification inform
lead operator to develop a reaction strategy.
Record results, time, date and initial on the NAJA form and place in appropriate log
book.
***Dextrin Equivalent
This test should be performed in concurrence with the Laboratory Procedure – 13
Starch Test.
This test should be performed regularly to ensure proper enzyme activity. Time
intervals will depend on filling rate, more than likely on a per volume basis.
This test is a measurement method to inform operators of residence time in the tank
and to determine if input to the tank needs to be reduced to maximize enzyme
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OBTAINING SAMPLES FOR TESTING
hydrolysis before product is transferred to fermentation/saccharification. This ensures
all starch has been broken down into usable dextrin molecules.
Obtain samples (approximately 4 grams) from the liquefaction tank near the outlet
pump. These samples should in theory have the longest residence time in the
liquefaction tank and thus would be the best indicators of starch hydrolysis.
Perform Dextrin Equivalent in accordance to Laboratory Procedure – 06 – Dextrin
Equivalent.
Results for the Dextrin Equivalent should be approximately 12 - 15. If results are less
than this range, report it to the lead operator to develop a reaction strategy.
Record results, time, date and initial on NAJA form and place in appropriate log book.
Moisture and Dry Solids Test
This test should be done regularly to ensure proper drying has been completed on
products. This test should be completed on DDGs, Wetcake, Slurry, Liquefaction,
Syrup, Centrate.
Tests should be completed on the slurry at more frequent intervals to ensure
approximate values of 28-30 percent solids.
Initially, samples from the fermentation tanks will be taken as the fermenter is filling
to get a trend developed. Once we get proficient in the process, the remaining
moistures should be completed once every 6-8 hours.
Obtain enough sample to perform test. Weights required are approximately 2 grams
of sample per test. Perform analysis in accordance to Laboratory Procedure -07
Moisture and Dry Solids Test.
Record results, time, date and initial on NAJA form and place in appropriate log book.
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NAQM - 06 OCT 05
OBTAINING SAMPLES FOR TESTING
***pH analysis
Before performing tests, calibrate pH probe according to the instructions in
Laboratory Procedure 23 – pH Probe Calibration – Fill out NAJA form for pH
calibration and place in appropriate log book.
Obtain samples from the slurry tank, liquefaction tank, yeast conditioner, fermentation
tanks, and caustic system.
pH range is critical for enzyme activity and yeast cell growth. Diligence must be used
when checking yeast conditioning and fermentation pH as well as the liquefaction
tank. Incorrect pH will hinder or completely stop the fermentation process.
pH ranges are as follows: This list will be made available shortly.
SPECIFIC TANK
pH Value Range
Liquefaction Tank
Slurry Tank
Yeast Conditioner
Fermentation Tank
Caustic System
Saccharification Tank
5.7-5.9
5.7-5.9
Confirm that pH ranges fall within ranges specified. If ranges are out of specification,
inform lead operator to determine a reaction strategy.
Record results, time, date and initial on NAJA and place appropriate log book.
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OBTAINING SAMPLES FOR TESTING
**Sieve Analysis
Samples of dry ground grain should be taken from the point just before the addition of
water to the slurry blender. Sample size should be greater than 100 grams.
Operators should be taking samples on a regular basis to ensure proper grind
consistency and size and to ensure that the screen on the hammer mill is within
specification. This should happen once per shift.
Perform sieve analysis test according to Laboratory procedure 11 – Sieve Analysis.
Compare your results with parameter results. If results are not consistent with
parameter results, see Hammer mill SOPs (standard operating procedures) for
adjustments and or troubleshooting. (Troubleshooting is as of yet to be determined).
Record results, time, date and initial on NAJA form and place in appropriate log book.
***Starch Test
This test should be performed in concurrence with the Dextrin Equivalent test.
Obtain a small sample from both the slurry tank and the liquefaction tank. Slurry
sample should be placed in the bottom of one test tube and liquefaction sample should
be placed in the bottom of another test tube. Both samples should be roughly the size
of a dime.
Testing both samples ensures that starch is present in the slurry sample, and that the
liquefaction sample has no starch remaining. Perform test in accordance to Laboratory
Procedure 13 – Starch Test.
If test does not indicate expected result report it to the lead operator immediately and
devise strategy.
Record results, time, date and initial on NAJA form and place in appropriate log book.
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NAQM - 06 OCT 05
OBTAINING SAMPLES FOR TESTING
Density of Distillers Dry Grains
The operator should be performing this test on each truck, or train load leaving the
plant.
Perform the test in accordance to Laboratory Procedure 15 – Density Distillers Dry
Grains. Amount of sample should be roughly 75 grams and amount of ethanol should
be 300 ml.
If sample has too much syrup added, the material is difficult to handle. If too little
syrup is added, product is not as desirable. The expected result should be _______.
If expected result is not within specification of expected result, inform lead operator
immediately.
Record results, time, date and initial on NAJA form and place in appropriate log book.
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Fusel Oil Test
Procedure to be determined once consultant for the distillation comes.
This test is required at startup to ensure the fusel oils are being drawn off at
appropriate distillation trays to maximize removal.
Sulfamic Acid Concentration??? – to be determined…disregard further
procedure.
This test should be done once when cleaning is required of the beer column and
evaporator.
Obtain sample from evaporator condensate tank. This sample should not be very
large. Only one gram of condenstate and one gram of sulfamic acid from the tank is
required to perform this test.
Perform this test in accordance to Laboratory Procedure 16 – Sulfamic Acid
Concentration
If expected result is not within specification of expected result, inform lead operator
immediately.
Record results, time, date and initial in appropriate log book
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