Biofuels and Green Concrete

Courtesy: thinkprogress.org [5]

In the development of new energy resources, researchers explore every possible revenue stream to make a resource economically viable.  In the case of corn ethanol, that means selling a portion of the waste stream as cattle feed [1].   When it comes to switch grass, wood chips and other cellulosic materials, however, the waste stream has largely been dumped or burned.  Thanks to some promising research at Kansas State University, that could change.

Researchers at the school found that the byproducts of lignin and cellulosic material could be used in concrete mixes to strengthen the material up to 30% while significantly reducing carbon dioxide emissions [2].  This finding goes hand in hand with a new report from the National Institutes of Standards and Technology.  The NIST report looked at different mixes already being used to ‘green’ concrete and the kinds of measurements necessary to ensure the concrete remains strong [3].

Cement Plant Courtesy: Wikimedia Commons

In order to understand the implications of these findings, it is helpful to see the energy and environmental impacts of concrete production. The U.S. cement industry uses some “400 million gigajoules of energy each year, which is equivalent to the energy required to power 3 million homes each year [4].”  Carbon dioxide emissions for the industry account for 5% of the U.S. total, according to the same report.

While the KSU study remains in the early stages, the findings pose a promising win, win, win scenario for biofuels, concrete and the environment.

References

1)      http://www.ers.usda.gov/media/147398/fds09d01.pdf

2)      http://www.k-state.edu/media/newsreleases/mar13/concrete31413.html

3)      http://www.nist.gov/el/building_materials/concrete-040313.cfm

4)      http://www.nist.gov/customcf/get_pdf.cfm?pub_id=913076

5)      http://thinkprogress.org/climate/2013/01/18/1466121/new-report-calls-on-europe-to-meet-its-2020-transport-fuel-standards-without-reliance-on-biofuels/?mobile=nc

What is Masdar City?

I was able to volunteer at the Cleantech Forum 2010 in late February. There I became familiar with Masdar, the lead sponsor. Masdar is located in the heart of the global oil and gas industry, Abu Dhabi, but it’s all about renewable energy and sustainable technology. In short, their mission is to turn Abu Dhabi in to an international hub for renewable energy and support the development, commercialization and adoption of sustainable technologies. Their four integrated business units (Masdar Institute, Masdar Carbon, Masdar Power and Masdar City) are all cutting edge, but I’d like to focus on what they call the “physical embodiment of Masdar,” Masdar City.

The thought is to create a place for innovators and entrepreneurs to test energy science, city design, sustainable development and environmental architecture. The focus is not only on test and design, but also on making an alluring place to live and work. If your creating the city of the future and money is not an object(budgeted at $22 billion), why not reach for the sky? They have!

Masdar City will be powered by 100% renewables, it will be zero waste, zero carbon and it will have a sustainable water system. Transportation, materials, foods…all sustainable. They are going all out and the level of detail is amazing. From the orientation and width of the streets to the wind cones (shown in the Masdar Headquarters photo above) that naturally ventilate interior spaces to the retractable shades (shown below) covering City Plaza, nothing was overlooked.

Transportation is beneath the city, leaving the ground level open for pedestrians. The transportation system includes a light rail and a Personal Rapid Transport (PRT) system that a transports up to 4 adults to any PRT station at the touch of a button.

The Masdar Institute of Science and Technology(MIST), developed in cooperation with MIT will be at the heart of the R&D in Masdar City. It will eventually be home to 600 master’s and PhD students, with over 100 faculty members. MasDar City with also be the home of the International Renewable Energy Agency (IRENA) headquarters and host operations for companies like GE and BASF.

They are currently in Phase One of seven, which focuses on MIST. This means that first residents will be students testing new technologies, while being test subjects themselves. I would encourage you to learn more about Masdar City.

Source: http://www.masdarcity.ae/en/index.aspx

Corn Ethanol and Ham Sandwiches

In recent years, there has been much discussion about the energy balance of certain biofuels, particularly corn ethanol, cellulosic ethanol, and biodiesel.  Scientists have attempted to establish, using life cycle analyses (LCA), the merits of these fuels–most importantly, their “energy balance” or “energy return on investment” and lifecycle greenhouse gas emissions reduction.

The energy balance of a product is defined as the energy content of the product minus the sum of all energy inputs required to produce the product.  For example, the process to convert one bushel of corn into ethanol requires direct inputs of heat and electricity.  However, it also requires secondary inputs such as diesel fuel to drive the tractor to harvest the corn, as well as energy to build the tractor.  These analyses get very complicated, and it is not clear where the “system boundary” should lie. Does the fuel for the tractor count as an input? Most definitely.  What about the energy content in the ham sandwich the hapless farmer ate for lunch? Maybe–but he has to eat whether or not he is harvesting corn.  Should we count the energy for the tractor to harvest the wheat to make the sandwich? Should we be doing energy balances on ham sandwiches? And if the energy in a ham sandwich is less than the sum of the energy inputs, should we stop making ham sandwiches?

Obviously the answer is no.  Ham sandwiches are delicious, and I like eating them.  I also like putting mayonnaise and mustard on my sandwiches, condiments with abysmally low energy content.  And, of course, drive to the grocery store to buy these things.

The upshot of all this is that people do not use energy–they use heat, light, mobility, and consumable products (like food and toilet paper), all of which require energy inputs.  Thus the energy balance is useful for determining how some goods compare with others, just like price.  It would be useful to compare the price of two supplementary goods (such as gasoline and ethanol) in deciding which one to purchase.  But it would be strange to arbitrarily decide that if a fuel costs more than $1/mile, then it is not an efficient option.

Critics of certain biofuels will often point to the energy balance calculation as the “smoking gun” that these fuels are inefficient and a waste of energy–or indeed, an evil plot perpetrated by the farm lobby, big business, or big government.  What they instead should do is compare the energy balance of ethanol with that of gasoline, a common substitute.  These same critics might be surprised to find out that it requires 1.19MJ of fossil energy to produce 1MJ of gasoline [1], resulting in a negative energy balance.  Corn ethanol, in comparison requires only .77MJ of fossil energy for 1MJ of corn ethanol [1], an improvement of 54%.  The energy balance calculation is therefore best viewed in a relative, rather than absolute sense to avoid confusion.

[1] Farrell, A. E.; Plevin, R. J.; Turner, B. T.; Jones, A. D.; O’Hare, M.; Kammen, D. M. Ethanol can contribute to energy and environmental goals. Science. 2006, 311, 506–508.

Hope in Algae

Up close view of algae

As the human population grows, our energy resources slowly mitigate. Within the past few years, energy has become more precious due to shifts in the economy and our struggle to be independent of countries which provide fossil fuels at high costs. This shift has revitalized our search for a source of energy that can be produced domestically and in a closed loop, a source that will sustain us for years to come.

Unfortunately, biofuels derived from crops such as corn and soybeans does not quite cut it due to its effect on the food market and its low oil yield per acre. According to this article, if the U.S. were to devote all of its corn and soybean production to fuels, it would only meet about 12% of the U.S. gasoline demand, and this is not accounting for the current fossil fuels it would take to produce the actual biofuel. Thus, many of us instill our hopes onto a more efficient organism: algae.

There exists a plethora of benefits in employing algae as a source of biofuel. One such benefit is that algae does not require as much land as a food crop in order to produce equivalent yields of oil. Additionally, the fact that algae is not a food crop eliminates food partitioning concerns as well. Another benefit is that algae can grow in wastewater or salty water, thus diverting us away from the use of freshwater. However, it has been found that algae produces more oil through the use of freshwater. Moreover, since algae is a photosynthetic organism, it needs carbon dioxide, therefore consuming about 14 kilograms of the greenhouse gas for every gallon of oil. Furthermore, the fuel derived from algae had slightly better mileage than petroleum-based jet fuel in a test flight done in early 2009, illustrating algae’s compatibility with current engine designs.

So if algae has so many positive aspects as a biofuel, then why has it not been commercially available yet? One thing is that it is not very economical to produce, thus rendering them uncompetitive with fossil fuels. According to this article, algae-based fuel can range from $10 to $100 per gallon, much greater than the $60-$80 per gallon of petroleum oil. The energy costs to pump water to the algae can incur add to steep pricing as well. Overall, the most expensive components in algae biofuel production come from harvesting and extraction.

Process of converting algae to biodiesel

Regardless of these high costs, I think it would be worthwhile and within our best interest to promote biofuels derived from algae. The marginal benefits substantial outweigh the marginal costs; there is no other way to see it. If the appropriate policy changes are made within the near future, I feel that those changes would greatly facilitate algae’s rise to commercial usage. Some policy changes could offer credits to companies who utilize algae to reuse carbon dioxide, in addition to capturing it.  Algae’s potential as a fossil fuel replacement is astonishing and I hope that we can tap into that potential in the coming years.