6 Precautions to Consider While Dehydrating Ethanol

Purifying ethanol requires running your distilled ethanol through molecular sieve beds in order to produce over 99% pure ethanol.  In order to dehydrate ethanol thoroughly most plants require that you have ten’s if not hundred’s of thousands of pounds of sieve installed in your vessels.

Making a significant mistake here could be hazardous to your co-workers and it could cost your plant a lot of money if you end up rolling your beds or if you have to shut down the vessels for awhile so here are six precautions to be aware of when running your sieve beds.

1. Watch the temperature – The adsorption process creates a lot of heat energy; do not let temperatures exceed 600 degrees Fahrenheit at any time.
2. Start the dehydration procedure with 200 proof ethanol, if you do not have 200 proof ethanol available, use extra caution until a stream with low water content is available for recirculation.
3. Avoid massive slugs of liquid, these can stir the bed.  Liquids may need to be drained while you are adding the wet feed.
4. Avoid rapid pressure fluctuations, these can cause bumping or lifting in the bed.  Pressure is normally released in order to control temperature.  Be aware that as sieve and ethanol/water streams are in contact with one another intermolecular frictional heat can occur.  Heat releases of up to 1,800 BTUs/lb of adsorbed water and 700 BTUs/lb  of adsorbed ethanol can occur.
5. Watch out for hot spots on the bed.  This can be avoided by having a recirculating feed rate that is high enough to maintain a vigorous flow throughout the sieve beds.
6. Make sure you purge the air.  Ethanol is a flammable vapor and it is running through your beds at high temperatures and in the presence of oxygen.  Purging the air can prevent fire hazards.

Great Biofuel Potential For A Non-Edible Plant

What is Arundo Donax?

Arundo Donax is a large cane plant that is native to Asia and parts of Africa.  It is currently showing great potential as a biofuel producing plant, and as a feedstock for producing cellulosic ethanol.  Despite being native to these portions of the world humans have brought it to Europe and North America, showing that it can thrive in versatile climates.

The stem of the Arundo Donax plant is very durable and sturdy and has been used throughout human history to make fishing poles, walking sticks, and many different types of flutes.  Currently they are used to make the reeds for woodwind instruments like the clarinet, saxophone, oboe, and bassoon, but recent studies are showing the potential this plant has to be converted into biofuel.

Arundo Donax has great biofuel potential because of how large the plant is and how fast it can grow.  Arundo Donax grows to heights between 20 and 33 feet tall on average, and can be harvested twice a year per field it is grown on.  Large amounts of fertilizer are NOT needed to grow this plant, and additionally it is also resistant to biotic and abiotic stresses.   This means it does not require a lot of pesticide thus saving farmers or growers of this plant a considerable amount of money.

Arundo Donax has also shown to offer protection against soil erosion and land degradation, and it even has even adapted to grow in saline (salt) land and water.  This ability to grow in harsher conditions and on harsher lands means that Arundo Donax will not need fertile land that is required to grow food crops, another major benefit.

States in GREEN are locations where Arundo Donax grows in the U.S.

Arundo Donax yields approximately 8,000-8,400 BTU’s of energy per pound, and about 20-25 tons of the plant can be produced per acre.  These energy yields plus its ability to grow in difficult areas makes this plant a great choice for producing biofuel.

Arundo Donax is already beginning to be applied to biofuel production.  Midway through 2012, construction on the largest cellulosic ethanol facility in the world will be completed in Italy.  The Crescentino Plant will be able to produce over 13 million gallons of cellulosic ethanol a year.  The primary feedstock for this plant will be Arundo Donax.

As the world continues to look towards alternative forms of energy, Arundo Donax looks to be another potential and realistic source of alternative energy.

Sources:

http://www.chemicals-technology.com/projects/mg-ethanol/

http://plants.usda.gov/java/profile?symbol=ardo4

http://www.biggreenenergy.com/default.aspx?tabid=4269

Part 3:  Trends in Ethanol Energy Gains and the Energy Contributions of Ethanol Co-Products

This is the final blog article that discusses ethanol’s ability to produce energy gains.  The previous two articles focused on proving that ethanol is currently producing positive energy gains and proving that the primary research done by David Pimentel (research that claims ethanol is producing a net energy loss) is very flawed.

Ethanol has been producing positive energy gains for the past couple of decades as well as reducing the amount of energy needed to produce ethanol.  Technology has improved the efficiency of ethanol plants currently and will continue to do so as we move towards the future. In addition to improving the technology in ethanol production, ethanol also produces a number of co-products besides fuel that also increase the total energy yields of ethanol plants.  Both of these factors play a large role in ethanol producing positive energy gains.

Technology has improved many different areas in ethanol production.  Studies show that it took 5.8 gallons of water to produce 1 gallon of ethanol in 1998, in 2010 it took 2.7 gallons of water to produce 1 gallon of ethanol.  This in turn helped to improve the BTU’s of ethanol produced ratio to BTU’s of energy used to produce ethanol.  Positive ethanol energy gains have increased from 1.37 BTU’s of energy in 1996 to 2.3 BTU’s of energy in 2005.

Note: BTU stands for British Thermal Unit, it measures how much energy is required to heat 1lb of water (or .11 gallons of water) from 39 degrees Fahrenheit.  1BTU=1055 Joules of Energy

In the 2010 NREL  report Current State of the U.S. Ethanol Industry ethanol producers had reduced water consumption by 26.6% from the years 2001 to 2006.  The report went on to say a typical sized ethanol plant uses as much water as town of 5,000 people or as much water as an average sized golf course.

Dr. Steffen Mueller at the University of Illinois at Chicago has researched how ethanol plants have become more energy efficient.   His study found ethanol plants have been able to reduce the amount of electricity they use by 32% from the years 2001 to 2008.

Meuller’s study also found that dry mill ethanol plants had reduced thermal energy by 28% since 2001.  Dry mill ethanol plants were using  26,000 BTU’s of energy on average to produce a gallon of ethanol.  A gallon of ethanol yields approximately 77,000 BTU’s of energy.

Note: Dry mill ethanol plants represent over 90% of the current ethanol plants in operation in the United States.  The remaining 10% are called Wet Mill Plants.

These improvements in technology have helped to increase ethanol’s energy outputs.  In addition to improvements in technology ethanol production allows the production of co-products.  These products which can also be factored into ethanol total production include:

• Distiller’s Grains -These are used as animal feed.  28% of corn used to produce ethanol is recycled and reused as animal feed.   Ethanol production currently gets around 16lbs of distiller grains from each bushel of corn. (1 bushel of corn = 56lbs).
• Carbon Dioxide – This is another by-product of ethanol production.  During the distillation process C02 is produced, this gas is usually resold to soda companies or any other company that produces carbonated beverages.

All of these technological trends show that ethanol is creating energy gains.  As the ethanol industry continues to grow the technology to produce ethanol will continue to get more efficient which will give the world a renewable, effective, and efficient energy source.

Sources:

Pimentel/Patzek Article Oil Ties and Arguments  http://www.biofuelsjournal.com/articles/ethanol_industry_refutes_david_pimentel_s_study_showing_negative_energy_balance_for_ethanol-27165.html

2002 U.S. Department of Agriculture Study http://journeytoforever.org/ethanol_energy.html

Pimentel Claims: http://www.freelists.org/post/biofuels-forum/Key-Differences-between-PimentelPatzek-Study-and-Other-Studies,1

http://journeytoforever.org/biofuel_library/PimentelComments4_5_05.pdf

National Renewable Energy Laboratory See Section 7.1 Net Energy Balance http://www.nrel.gov/analysis/pdfs/doe-02-5025.pdf

USDA Switchgrass yields http://www.scientificamerican.com/article.cfm?id=grass-makes-better-ethanol-than-corn

U.S. Ethanol Distiller Grains http://growthenergy.org/images/reports/ethanol_livestock.pdf

Dry Mill Ethanol Efficiency Gains http://www.ethanolrfa.org/exchange/entry/from-farm-to-biorefinery-ethanol-production-efficiency-improves/

Dry Mill Ethanol Efficiency (Thermal Energy) http://www.ethanolrfa.org/news/entry/dry-mill-ethanol-production-shows-significant-improvements-in-efficien/

2.1.1.1 DGS in the U.S. http://www.transportation.anl.gov/pdfs/AF/527.pdf

Part 2: Disputing Pimentel’s Ethanol Research

This is the second article in a three part series that focuses on debunking the myth that ethanol production creates a net energy loss.

Last weeks article focused on this myth’s origin and its strongest supporters  David Pimentel and Tad Patzek.  This week will focus on debunking the some of the inconsistencies found in their research compared to the results of other studies done on ethanol energy outputs, and it will discuss some of the key energy omissions from Pimentel’s/Patzek’s 2001 study.

Below is  a  list of the Pimentel Study’s most glaring problems along with rebuttals to why they are problems.

1. Pimentel – Ethanol production yields a 29% loss in energy when produced from corn
•    The U.S. National Renewable Energy Lab found a producing ethanol yielded a 30% gain in Energy when comparing 1BTI of fossil fuel to 1BTU ethanol.  This study was done shortly after Pimentel’s Study.
•    In the National Renewable Energy Laboratory (NREL) 2010 report Current State of the U.S. Ethanol Industry the NREL finds the following
1.  The net energy balance of corn ethanol has increased from 1.76 BTU’s to 2.3 BTU’s since 2004.
2.  For every BTU of energy required to make ethanol, 2.3
   BTU’s of energy are produced.
3. Over the past 20 years ethanol yields have increased over 10% and corn yields have increased 39%.
2. Pimentel – Between 45% to 57% more energy would be lost in producing ethanol from wood or switchgrass
•    The United States Department of Agriculture conducted a study on switchgrass and found that it had a 540% energy yield, meaning it produced 540% more energy than it took to produce it.
3. Pimentel’s study uses outdated information or incorrect  data
•    Pimentel uses data for corn yields that exists before 1992.
•    Pimentel uses values for measuring energy to produce ethanol that were used in the 1980′s.
•    Pimentel uses 1990 world-wide values, not recent U.S. values for his figures determining how much energy is needed to produce fertilizer.
4. Pimentel’s study omits crucial data that could help determine ethanol’s energy production
•    Pimentel does not factor in dried distiller grains into ethanol’s energy output.  1/3 of all ethanol produced gets reused as distiller grains, which in turn is used to make animal feed.  This is huge source of energy not included in Pimentel’s study.

Pimentel’s study has many flaws making it an unreliable source of information.  His findings have been discredited by many scientists and government agencies within the U.S.  Next week will be part three of this series which will discuss the energy ethanol is currently producing and what the ethanol industry is expected to produce.

Sources:

Pimentel/Patzek Article Oil Ties and Arguments  http://www.biofuelsjournal.com/articles/ethanol_industry_refutes_david_pimentel_s_study_showing_negative_energy_balance_for_ethanol-27165.html

2002 U.S. Department of Agriculture Study http://journeytoforever.org/ethanol_energy.html

Pimentel Claims: http://www.freelists.org/post/biofuels-forum/Key-Differences-between-PimentelPatzek-Study-and-Other-Studies,1

http://journeytoforever.org/biofuel_library/PimentelComments4_5_05.pdf

National Renewable Energy Laboratory See Section 7.1 Net Energy Balance http://www.nrel.gov/analysis/pdfs/doe-02-5025.pdf

USDA Switchgrass yields http://www.scientificamerican.com/article.cfm?id=grass-makes-better-ethanol-than-corn

U.S. Ethanol Distiller Grains http://growthenergy.org/images/reports/ethanol_livestock.pdf

Part 1: Does Ethanol Cost More Energy to Produce than to Use?

Does ethanol cost more energy to produce than to use?

Since the ethanol industry has been the first industry to prominently challenge the oil industry in the U.S. over the fuel market in almost a century a lot of criticism has been thrown towards ethanol.  Ethanol costing more energy to produce than to use has been one of the most common attacks against the ethanol industry.  This statement is not true and this three part series of blog articles looks to show you the origins and motivations behind this idea, debunking the data and discovering the flaws of the research behind ethanol costing more energy to produce than to use,  and eventually to show that ethanol can produce more energy than is used to produce it.

The biggest contributor towards the “ethanol produces a loss in energy” fallacy was written by University of Cornell Professor of Entomology David Pimentel and University of California, Berkley, Professor Tad Patzek in 2001.  Pimentel’s research is frequently used by supporters of the oil industry to try and bring down the credibility of ethanol as a source for fuel.  Furthermore their claims don’t stack up to the research that has been done by other scientists.

The only other studies that show ethanol costing more energy to produce than to use are all done in the 1980′s and early 1990′s.  It is possible that ethanol may have cost more energy to produce during those times but technology has improved since then even by the time Pimentel’s study had gone underway.  A year after Pimentel’s study was released the U.S. Department of Agriculture found that ethanol gives 34% more energy than it takes to produce it.  Below is a graph showing how Pimentel’s results aren’t matching up with current ethanol studies.

Pimentel’s study features a number of disputed claims and other problems in regards to how the experiments were performed and what they did and didn’t factor in.  These problems/disputed claims are:

• Ethanol production yields a 29% loss in energy when produced from corn
• Between 45% to 57% more energy would be lost in producing ethanol from wood or switchgrass
• Pimentel’s study uses outdated information and data
• Pimentel’s study uses data incorrectly
• Pimentel’s study omits crucial data that could help determine ethanol’s energy production

Further hurting the Pimentel and Patzek study is Patzek’s connections with the oil industry.  At the University of California Patzek is the director of the schools oil consortium which is financially backed by Chevron and Phillips.  He also worked at Shell for over decade as a research consultant and expert witness.  These ties to oil indicate a bias in their study towards the oil industry, which has been working to remove ethanol from the fuel market, securing it exclusively for themselves.

Part 2 in this series will be focused on debunking Pimentel’s results and showing how some of the data collected from Pimentel’s research was old or outdated.

Sources:

Pimentel/Patzek Article Oil Ties and Arguments  http://www.biofuelsjournal.com/articles/ethanol_industry_refutes_david_pimentel_s_study_showing_negative_energy_balance_for_ethanol-27165.html

2002 U.S. Department of Agriculture Study http://journeytoforever.org/ethanol_energy.html

Pimentel Claims: http://www.freelists.org/post/biofuels-forum/Key-Differences-between-PimentelPatzek-Study-and-Other-Studies,1

http://journeytoforever.org/biofuel_library/PimentelComments4_5_05.pdf

National Renewable Energy Laboratory See Section 7.1 Net Energy Balance http://www.nrel.gov/analysis/pdfs/doe-02-5025.pdf

USDA Switchgrass yields http://www.scientificamerican.com/article.cfm?id=grass-makes-better-ethanol-than-corn

U.S. Ethanol Distiller Grains http://growthenergy.org/images/reports/ethanol_livestock.pdf

Dry Mill Ethanol Efficiency Gains http://www.ethanolrfa.org/exchange/entry/from-farm-to-biorefinery-ethanol-production-efficiency-improves/

Dry Mill Ethanol Efficiency (Thermal Energy) http://www.ethanolrfa.org/news/entry/dry-mill-ethanol-production-shows-significant-improvements-in-efficien/

2.1.1.1 DGS in the U.S. http://www.transportation.anl.gov/pdfs/AF/527.pdf