Clearing the Air
By Diane L. Godwin
It would be difficult for many to imagine a coach asking an Olympic sprinter to run his or her best time with congestion caused by a cold. However, that analogy becomes true and applicable to the way vehicle engines are designed and driven every day. Drs. Sundar Krishnan and Kalyan Srinivasan, assistant professors in mechanical engineering and researchers at the Advanced Combustion Engines Laboratory at the Bagley College of Engineering's Center for Advanced Vehicular Systems (CAVS), are designing novel engine combustion strategies for the vehicles of the future that will achieve higher fuel economy and are safer for the environment.
“The biggest problem with most current gasoline engines is the throttle in the intake manifold. It’s like one of us having a heavy cold and being asked to sprint up a flight of stairs,” explained Srinivasan. “The throttle blocks the engine’s breathing efficiency, making it have to work harder and, therefore, it burns more fuel.”
The two researchers are creating innovative engine combustion concepts that move away from traditional, spark-ignited gasoline engines to a more optimized engine design that incorporates novel low temperature combustion (LTC) technology. The advantage of this technology is that it can be tailored for fuels made from biomass—forest and agricultural harvest byproducts—to enable highly efficient engines to meet performance requirements while reducing harmful exhaust emissions, thus creating cleaner air that ultimately energizes everything and everyone.
“Our research is not just fuel-centric or solely focused on engine design or even trying to adapt current engines to run efficiently with renewable fuels; that is the traditional approach,” said Krishnan. “We’re working on futuristic solutions of how to co-design new engine combustion strategies and biomass-derived fuels so they complement rather than work against each other.”
Mississippi State is one of only a handful of universities in the nation that is adapting renewable fuels for advanced combustion concepts. This “bottom-up” approach has a high probability of positively reinvigorating the auto industry, economy and, at the same time, protecting the environment.
“Traditional engine technologies are not optimized for renewable fuels. Consequently, alternative fuels, such as E85, a gasoline and ethanol blend, are not giving vehicles the same fuel economy and range as gasoline and diesel,” said Krishnan. “However they can meet EPA regulations by emitting lower emissions that are safer for our environment.”
Krishnan and Srinivasan’s work is possible because they collaborate with a unique alliance of experts from different academic areas who work together at the Sustainable Energy Research Center to create renewable alternative fuels from Mississippi’s natural resources.
“They’ll give us biomass-derived fuels to perform our low-temperature engine combustion experiments. We’ll characterize the fuel in its ability to produce power and to ensure high efficiency and very low emissions,” Srinivasan explained. “Based on our feedback, they’ll tweak the fuel to meet engine requirements and we’ll meet them in the middle by tailoring the engine combustion strategy.”
The two researchers are working on an umbrella of LTC concepts that are capable of handling different fuels, meaning they can design engines that efficiently work with many fuels. Their work holds enough promise that a truck engine manufacturer has donated one of their heavy-duty engines in support of Srinivasan and Krishnan’s LTC research to further refine the concept that they hope will break into the commercial market in the future.
“The traditional engine technology uses catalytic converters to clean the exhaust before it is emitted into the atmosphere. The catalytic converter is expensive to manufacture, difficult to adapt to diesel engines, and it cuts down on the vehicle’s fuel economy,” said Krishnan. “That’s why engine manufactures are interested in our research. We can help them design and produce engines that will have a higher fuel economy, save them money and meet EPA regulations with cleaner exhaust emissions.”
“One of the most important things that we need to understand as a society is our responsibility to protect the environment. When you burn fossil-based, hydrocarbon fuels, its exhaust will emit additional carbon dioxide into the atmosphere,” said Srinivasan. “This research helps solve several issues. We’re designing engines and renewable fuels that will help lessen America’s dependence on foreign oil and obtain higher fuel economy. Plus, they will emit lower pollutant emissions that ensure minimal environmental impact and lower net CO2 emissions because the fuel will be obtained from renewable resources. In fact, we can progress toward a carbon-neutral energy economy by combining the two technologies to optimally work together.”
For more information about the LTC research project, contact Drs. Srinivasan or Krishnan at firstname.lastname@example.org or email@example.com.
Reprinted with permission from Dimensions, 2008-2009 Annual Report for
MSU's Bagley College of Engineering
Yeast Studies May Yield New Bio-diesel Source
By Kristen Dechert
Dr. Mark Lawrence, microbiologist and Professor in the College of Veterinary Medicine at Mississippi State University (MSU), has teamed with Dr. Todd French, leader of SERC’s lignocellulosic conversion thrust and Assistant Professor of Chemical Engineering at MSU, to study Rhodotorula glutinis, a red-pigmented strain of yeast with characteristics that make it viable for bio-diesel production. The two MSU researchers have a three-year history of collaboration. They began with bacterial studies and progressed to this yeast work, which has been ongoing for the past year.
French’s chemical research centers on how this yeast can utilize fat accumulation in biomass, specifically switchgrass, for extraction to make bio-diesel, and he has teamed with Lawrence for biological study of the yeast. Lawrence’s work focuses on identifying genetic pathways that control the fat accumulation in this yeast. Identification of these pathways can allow specific gene alterations to increase the yeast’s fat accumulation, and French can use this for more efficient bio-diesel production.
Sequencing the genome is the first step in this process, and sequencing is no simple task because this type of yeast has 20 million base pairs. To accomplish this, Lawrence’s team utilized next-generation sequencing technology to sequence the genome 20 times over for accuracy. State-of-the-art computer analysis then assembled the genome sequence. Even after this process, which takes several months, Lawrence and his team must still look for errors, or holes in the sequence, and correct them before the sequencing is complete.
Lawrence’s team then observes gene expression under various conditions of carbon and nitrogen ratios; elevated carbon generally means better fat accumulation. Altering these ratios allows the team to isolate specific genes that “turn on” fat accumulation when ideal conditions are reached. After identifying these genes, the team’s goal will be to alter them and coax the yeast into turning on fat accumulation sooner for bio-diesel production.
To accomplish this project, a team with expertise in multiple areas is required. Lawrence works with Drs. Susan Bridges and Yoginder Dandass in the MSU Department of Computer Science and Engineering as well as Drs. Shane Burgess and Debarati Paul (pictured above with Lawrence) in the MSU College of Veterinary Medicine.
The team expects the genome sequence to be finished by the end of the month. While waiting on the computer to finish analyzing the sequence data, Lawrence and his team are growing Rhodotorula in the lab under certain carbon and nitrogen conditions to isolate protein and RNA. Doing so will help them observe gene and protein behavior and identify ideal conditions for fat accumulation. Lawrence expects this gene and protein expression data to be ready for study when the sequencing is complete, allowing the two steps to be combined for identification and alteration of specific genes.
In the future, Lawrence and French are planning to study the red pigment produced by Rhodotorula. The pigment contains beta carotene, which is an important antioxidant that can help prevent cancer, and the two hope to use the yeast to produce the vitamin from biomass.
Renewable Fuel that Supports a Carbon Neutral Cycle
by Diane L. Godwin
They’ve lived beneath the earth for millions of
years and have enhanced the quality of life for generations. Fossil
hydrocarbons are mined for making traditional fuels to power engines
that release carbon dioxide (CO2) into the atmosphere. Experts
assert that these emissions create global change by increasing the
earth’s overall temperatures, called a greenhouse gas effect. It
occurs because the Earth’s environment doesn’t have enough rain
forests and vegetation to feed on the added CO2 that is released. To
help reduce the amount of CO2 emitted, engineers invented catalytic
converter technology for vehicles. Environmental scientists affirm
that there’s been significant improvement, but claim more needs to
Two chemical engineering faculty members,
Drs. Rafael Hernandez and Todd French have invented a process that
can provide the world with clean energy just by tapping into the
world’s abundant supply of wastewater. They’ve discovered
microorganisms, naturally found in wastewater, grow fat with
bio-oil. The discovery means they can provide clean energy by making
biocrude from the bio-oil the microorganisms produce, creating a
carbon neutral environment because the microorganisms depend on CO2
to grow larger. The process could resolve some controversial issues
affecting today’s society by creating energy that’s safe for the
environment and by producing a fuel that will help America become
less dependent on foreign oil.
Open a tiny test tube filled with oil extracted
from the microorganisms and, naturally, one would be apprehensive
about inhaling a deep breath or even holding the small vial.
However, the smell and consistency of this wastewater microorganism
byproduct is opposite of what one would expect. In fact, the
experience is close to opening a tub of butter. The rich, yellow
color, along with the creamy consistency, looks and even smells
like, well, butter. Dr. Alexei Iretski, a native of St. Petersburg,
Russia, and an expert in improving the conversion processes of
catalysts, is working with Hernandez and French to convert this
creamy, butter-like substance into a biofuel. It is part of the
first phase of a General Atomics (GA) and U.S. Air Force $1.2
million contract to convert and commercialize the microorganism fat
into an alternative fuel that is every bit as efficient as gasoline.
“We’re developing a natural process that uses
Mother Nature’s resources. These microorganisms will grow fat with
oil when adding an inexpensive carbohydrate concoction,” said
Hernandez. “The benefits include clean drinking water, fuel that
will lessen our carbon footprint and will decrease the waste added
General Atomics, an innovative research and
development company that transforms and evolves technologies from
the laboratory to the marketplace, is managing the first phase of
the three-phase commercialization process. They’re working with
Mississippi State and the U.S. Air Force Research Laboratory, on a
yearlong process that involves research, initial full-scale facility
design, project management, and logistical planning. The partnership
gives French and Hernandez access to more than three million square
feet of engineering laboratories and state-of-the-art technology,
not to mention connections with General Atomics and the Air Force’s
“We can generate with municipal wastewater
treatment plants about seven billion gallons–not million–billion
gallons of biocrude a year,” said French. “Cities such as
Tuscaloosa, Ala., treats 30 million gallons of wastewater daily.
Chicago has one facility that receives two billion gallons a day and
could potentially produce 400 million gallons of biocrude annually.
This is a modest estimation of the potential impact we can make
using this technology.”
The Air Force Research Laboratory is relying on
long-range vision and planning when providing the financial backing
for the project. The Air Force hopes the eventual payoff of
financing the research and development will be in the form of lower
fuel costs for aircraft operations.
Bobby Diltz is the technical lead for the Air
Force Research Laboratory Deployed Energy Systems Group at Tyndall
Air Force Base in Florida. “An added advantage of this partnership
is that the Air Force has bases located across the country equipped
with wastewater treatment facilities, providing the basic
infrastructure, with little modification, to test and grow the
microorganisms that produce the oil that makes the fuel,” said Diltz.
“Plus, it could drive down the cost of our operations by hundreds of
thousands of dollars.”
Kevin Downey, project manager at General
Atomics, said that for the past four years GA has been conducting
cutting-edge research aimed at the production of biofuels.
“The advantage is that you’re leveraging the
existing infrastructure, taking advantage of the microbes that are
already present, adding algae to help clean the wastewater,
providing a cleaner water for discharge, and producing fuels for
sale that are safe for the environment. It is a win-win situation.”
For more information about the microorganism renewable fuel project,
please contact Drs. French or Hernandez at French@che.msstate.edu or Rhernandez@che.msstate.edu.
Reprinted with permission from Dimensions, 2008-2009 Annual Report
MSU’s Bagley College of Engineering
Graduate Student Profile:
Department and Degree Seeking:
Chemical Engineering, Ph.D. in Engineering
Concentration: Chemical Engineering
B.S. in Chemical Engineering, University of the Philippines Los Baños, 2005
Please discuss your area(s) of specialty.
One of my areas of specialty is bioprocess engineering in tandem with environmental engineering. This involves the application of concepts of biological process design (i.e., microbial cultures, fermentation) in modifying microbial consortia in the environment that are involved in biological treatment processes to produce high-value products, such as lipids, for biofuel production. The second involves chemical analysis of the products we extract from these natural microbiota with the use of chromatographic instrumentation (gas, liquid, ion chromatography). More recently, I received training in DNA extraction and analysis techniques in order to better understand the dynamics of the composition of the wastewater microbiota at the genetic level when subjected to the fermentation process for lipid production.
Please tell us about your thesis or dissertation project.
My dissertation project deals mainly with developing a process that utilizes municipal wastewater treatment plant influent and sludge streams as well as its established infrastructure to produce large quantities of oil to be used for the production of biofuels, such as biodiesel and green diesel. The h ypothesis is that by introducing a change, such as high carbon loading and high carbon-to-nitrogen ratio in the wastewater, we could trigger the indigenous microorganisms found in wastewater sludge to accumulate more lipids. The experiments that we conduct include cultures of the sludge microbiota using lignocellulose sugars (glucose, xylose, furufural, acetic acid) as substrate using batch, semi-batch, or continuous processes with the intent of optimizing the process to maximize oil yield. The fermentation data are then analyzed and fitted with kinetic models using computer software to produce kinetic and design parameters for commercial-scale design. Chemical analyses are conducted on the extracted lipids using gas and liquid chromatography to determine oil composition and quality. Finally, DNA extraction and analysis are being conducted on the biomass in order to understand the microbial composition dynamics in the sludge microbiota. The genetic data are then correlated with fermentation data to identify or in the future isolate potential lipid-producing microbial strains in the wastewater.
What additional research projects are you involved in at MSU?
Currently, I am involved in projects funded by the National Science Foundation and General Atomics that are similar to my dissertation research but with additional and/or modified objectives. In addition to this, I am involved in two SERC projects. The first involves the design of a pilot-scale facility to produce lipids from both wastewater sludge microbiota and oleaginous microorganisms. In the second project, I am working closely with Dr. Sandra Eksioglu and the Department of Industrial and Systems Engineering by providing experimental and technical data for them to use in developing optimum supply and logistic models in networking sugar plants, wastewater treatment facilities, and oil refineries in the State of Mississippi.
Please tell us about any recent or upcoming conferences and/or publications in which you discuss this SERC research.
I will be presenting a paper at the 2010 annual meeting of the American Oil Chemists Society later this month. In November, I will travel to Salt Lake City to deliver a presentation to the American Institute of Chemical Engineers at their 2010 annual meeting. In both meetings, I will be presenting mostly findings on the laboratory-scale experiments of lipid production by wastewater sludge microbiota using artificial lignocellulose sugar mixtures as well as some kinetic modeling and process scale-up design calculations.
Please discuss your upcoming research projects.
My upcoming research projects involve optimization of fermentation conditions and further chemical analysis of lipid extracts for cultivated wastewater sludge biomass to identify other lipidic materials that may be used for the production of high-value products other than biofuels. Examples include polyhydroxyalkanoates (PHA) for the production of bioplastics and microbial polysaccharides.
Winter 2010 News