By Mario A. Montes
Simplest plant could bring solution to complex problem
Alternative energy – a couple of words charged with calls to action, politics, skepticism and even the pop culture disdain of “whatever.” Its composition reads like a comic book tale that unleashes the forces of life – earth, water, wind and fire. And like in every comic book tale there is a hero: In this one it could be algal biomass.
What is it? Simple. It’s the same green slime that accumulates in your dog’s water bowl. And believe it or not, this slime, more commonly known as algae, produces lipids, or oil, that can be refined into biofuels.
New Mexico State University researchers are combining efforts to see if algal biomass is a viable substitute to the world’s dependence on fossil fuels. Researchers in disciplines including biochemistry, agriculture, chemical engineering, civil engineering and economics are each doing their part to come up with the best equation, substance and process to produce economically feasible biofuels from algae.
“Algae are far more efficient at using sunlight to make lipid than any plant species,” said Pete Lammers, a professor and biochemist in the Department of Chemistry and Biochemistry at NMSU. “You can also grow algae in the desert using brackish water that’s available close to the surface in eastern New Mexico, which also has abundant sunlight. This avoids competition for arable land between food and fuel producers.”
Lammers knows algae and has worked with the tiny organism off and on his entire career. But now that the cry for alternative energy sources has become louder because of climate change and last fall’s presidential campaign, Lammers has once again delved deeply into its viability. He is coordinating NMSU’s efforts in the algal biomass approach to the alternative energy equation. His part has been to develop different strains to optimize the lipid and reproductive growth of algae.
“One of the things we’re doing in my lab is investigating the inverse relationship between growth rate and oil content,” Lammers said. “The faster a population of algal cells are growing, generally the lower the oil content they have. When the algae become nutrient limited, the oil content begins to increase.”
The algae Lammers is working with can divide as fast as once per day in the peak season or summer time. He said they are looking at the triggers for accumulating higher concentrations of oil in algal cells and “trying to integrate algal cultivation practices with our knowledge of this dichotomy between growth rate and oil content,” Lammers said. “We are trying to develop cultivation practices that are built on understanding of algal physiology; trying to put together a staged process where we can always harvest the algae at the highest oil content. The idea is to make the most efficient use of the land requirements, the availability of sunlight and manipulate nutrient concentrations so we are getting a maximum biomass content and the maximum oil content out of the algal harvest.”
At NMSU’s Jett Hall is another member of the algal team. He is Shuguang Deng, associate professor of chemical engineering at NMSU. Deng is trying to produce a device that will reduce the three steps needed to produce a biofuel product into a one-step process.
“My job is to process the biomass once the algae is harvested,” Deng said. “You have to get the oil out from the biomass.”
At this time, a chemical extraction process is used to separate algal oil from the biomass. Then the solvents have to be separated from the algal oil and the oil undergoes a conversion process to make a biofuel product like biodiesel. The biofuel can be refined further to make gasoline or jet fuel, Deng said.
“We are trying to develop a new process to convert the biomass into biofuel in one simple step,” Deng said.
Working hand-in-hand with Deng and Lammers is N. Nirmala Khandan, a John W. Clark professor of civil engineering at NMSU. Khandan has created a bench-size model, or what is called a “racetrack reactor,” to grow algae in an enclosed structure, stimulated by artificial lighting.
“We build small-scale experiments and use these models to mathematically predict what will happen if you build a reactor 12-feet long or 30-feet long,” Khandan said. “There are several factors involved in this process, for example: the intensity of the sunlight; the time it spends in the reactor; the amount of algae that is growing and the rate at which they are growing; and the amount of nutrients that we feed. All these are variables and we need to put everything together to predict what will happen at a larger scale.”
Along with knowing the chemistry of algae and how to manipulate it, grow it and process it to run a combustion engine, a monetary reality must be established. In other words – is it cost effective? At $25 a gallon, biofuel is not practical, even though it appeared the price of a gallon of gasoline was headed that way last fall. For this analysis you need an economist, and C. Meghan Starbuck is that person.
Starbuck, assistant professor of economics at NMSU, is building several economic models that take into account the many materials, manpower, time and production costs to produce biofuels that would compete with today’s fuel prices.
“We’ve been working on this about a year to a year and a half. We have two, sort of basic economic models built. One is for a closed bioreactor system and the other is for an open-pond system,” Starbuck said. “Both models are relatively simple cost-based models that are telling us costs per gallon based on what Pete (Lammers) and the others think are the realistic yield rates that they think they can get the algae to grow.”
Among the factors that greatly affect cost are labor and algal biomass yield. Starbuck said because a commercial model has never been built, it is hard to determine the best formula. The current models are adding up to a cost scenario of $4 to $15 a gallon for biofuel, she said.
“The analysis and work that has been done so far shows that there really is a lot of potential in it. The work needs to be focused on how we commercialize it,” Starbuck said. The caveat to this is what happens when you increase to a commercial scale, and this, Starbuck said, is what NMSU researchers are trying to determine.
One outside organization working with NMSU researchers is the Center of Excellence for Hazardous Material Management (CEHMM), based in Carlsbad. NMSU’s Agricultural Science Center at Artesia has provided CEHMM a site to run open-pond and bioreactor experiments. Lammers and the others are working closely with CEHMM on these experiments.
During a recent open house at the Artesia site, Doug Lynn, CEHMM executive director, explained to New Mexico lawmakers and community leaders the feasibility of algal biomass production. He said CEHMM planned to expand the size of the pond experiments to get a better determination of commercial feasibility.
“This is a wonderful initiative that is at the same time making use of the best of traditional agriculture and giving us the chance to start to think in very innovative ways. It is the wave of the future on how we can start producing alternative fuels without competing with food sources, while allowing us to lose our dependency on foreign oil,” Waded Cruzado, president at NMSU, told the same lawmakers and visitors at the Artesia center.