Hello, my name is Nathan Kreutzer.
My UCARE project is,
The Environmental Impact of Hand Sanitizer Ethanol.
I worked with Gabe Cohen and Katie Mowat on this project.
My advisors were Dr. Bruce Dvorak and Dr. Ashraf Aly Hassan.
I would like to thank
the Nebraska Center for Energy Sciences Research,
and the Nebraska Public Power District,
for helping fund this research.
The agenda for this presentation today is as follows,
we'll begin with the project background.
We will then move into the product objectives.
We'll look at the methods used in this project,
and we will finally discuss
the data, results, and conclusions.
When COVID-19 first began to effect our entire world,
one of the first methods of prevention found
was a disinfection of hands and surfaces.
Alcohol based disinfectants became a standard
for disinfecting frequently touched surfaces,
especially when soap and water run unavailable.
The most common alcohol used in hand sanitizer
at the time was isopropyl alcohol.
Around the same time COVID-19 reached the United States,
a large refinery producing much of the world's
isopropyl alcohol had to be shut down.
Ethanol is a suitable replacement for isopropyl alcohol,
however at the time, many ethanol producers
were producing fuel grade ethanol,
which has much looser restrictions
than USP or topical grade ethanol.
The FDA for this reason temporarily raised
the impurity limits to help producers
more easily reach these impurity limits.
There are three main objectives on this project.
The first objective,
was to support the global fight against COVID-19
by helping ethanol plants meet the USP grade specifications.
The way we planned to do this was by identifying
the location where various impurities were produced
or recycled in an ethanol production process.
This would in turn help engineers find new ways
of ethanol purification, as well as operations optimization.
The second was identifying streams for use and innovative
waste treatment methods.
For example, bio scrubbers requires specific
nutrient solution depending strongly on the total nitrogen,
total phosphorus, total suspended solids, pH
and chemical oxygen demand.
The third is the environmental impact of USP grade
ethanol production.
We will look at the expected increase in hazardous
air pollutants, CO2 production and water consumption.
We'll now move in to the methods used on my project.
Initially, 17 samples were pulled from the dry mill
ethanol plant prior to adjustments allowing the plant
to produce USP grade ethanol.
The plant followed the above diagram's black and blue
process streams,
which is a common ethanol plant process flow scheme.
Another common ethanol plant process flow scheme
follows the black and gray data process streams.
The difference between the two schemes
is the addition of a distillation column,
thermal oxidizer and a dryer.
For many of the process streams between the two schemes
are the same, for this reason it was assumed
that most ethanol plants
have a similar stream characteristic.
The impurities we looked at were acetaldehyde, acetal,
propanol and methanol.
Seven of the samples, Mash 1 and 2, Beer 3 and 4,
Bottom 7, Thin Stillage 9, 10, 11, Corn Oil, Corn Syrup,
were high suspended solids.
For this reason, they were centrifuged.
The supernatant and the solids were tested separately
for impurities.
For testing we used a vacuum sorbent extraction (VASE),
in conjunction with a gas chromatography
and mass spectrometry, GC/MS,
two milliliters of liquid sample
or one gram of the solid sample was placed
in a 20 milliliter vile, with a sample pen.
The samples were vacuumed
at 30 millimeter of mercury
and placed in a 5600 SPEC for three hours
at 70 degrees Celsius and 200 RPM.
The samples were placed in a cooling tray for 10 minutes
before they were placed in the GC/MS for analysis.
For the water chemistry analysis, we looked
at four different properties, the total phosphorus,
the total nitrogen, total oxygen demand
and the total suspended solids.
The first three,
they were tested using TNT vials
and were placed in a HATCH DR2800.
The fourth property was analyzed using
the total suspended solids,
using the standard wastewater analysis technique.
We'll now move on to data, results and conclusion.
Figure A shows the concentration of impurities
in terms of parts per million throughout the plant,
as well as the flow rate of these impurities,
in terms of grams per minute.
Figure B shows the overall COD and impurity COD,
and the composition of the impurities COD
each impurity contributes.
Interesting things to be found from these diagrams.
First, acetal concentrations
appear at the beginning in the solids,
in the Beer 3 and Beer 4 but are of very low concentration.
In the distillation column, a portion of the acetaldehyde
is converted into acetal
and is concentrated in the distillation column tops.
The difference between the acetal and acetaldehyde
in a distillation column tops and molecular sieve
would combined to be higher than the intern
limits at 50 PPM.
Second, methanol accumulation within the distillation column
and molecular sieve loop.
This is due to the properties of methanol
and the separation principles using this loop.
Methanol is a volatile, small molecule.
Distillation column separate based on relative volatility.
The more volatile component,
leaves through the top of the column.
Molecular sieves, trap small molecules,
such as water and methanol,
recycling them back to the distillation column,
and lets larger molecules, such as acetal leave.
But, with the amount of methanol filtered out by the
molecular sieve,
the total would be below the normal limit of 200 PPM.
Third, propanol is not a compound regulated by the FDA
in USP grade ethanol.
However, it is regulated in other higher purity ethanol's.
The difference between the flow rate
and the distillation column tops,
and the molecular sieve, which show a significant amount
of propanol entering the final ethanol product.
The summary of the water quality impacts are seen
on the table on the left and correspond to the streams
in the figure at the right.
The streams with the highest solid content,
Mash 1, Mash 2,
or Beer 3, Beer 4, Bottoms 7
and Thin Stillage 9, 10, 11
and Corn Syrup 12,
have a high total nitrogen, total phosphorus
and total suspended solids.
The column tops five and molecular sieve reject 6
have high total nitrogen and total phosphorus.
This data may be helpful in determining potential
treatment methods.
The environmental impacts are as follows.
The majority of the hazardous air pollutant, HAPs,
are created during the fermentation process.
Additional separation won't lead to increase HAPs.
Additional separation techniques,
as of now, don't require excess water usage.
So, water demand is not expected to increase.
A common additional separation technique used is secondary
distillation.
Extra steam is required in the reboiler
for additional
distillation columns.
For this reason additional natural gas
will need to be burned,
and will increase the greenhouse gas released,
by usually 5 to 10%, but possibly as high as 100%.
Doing some simple calculations,
with the exception of the CO2 produced during fermentation
which many ethanol plants recapture, purify and sell,
a 30 milliliter travel sized bottle of ethanol based
hand sanitizer requires reduction of around
0.02 pounds of CO2.
Here are my sources used for this project.
Thank you, for listening to my presentation.