Beneath the Surface

Can we safely pump carbon underground instead of into the atmosphere?

UA professor of chemical and environmental engineering Kimberly Ogden is the next speaker in the UA College of Science Spring Lecture Series, Earth Transformed, which focuses on climate change. Ogden will talk about "Carbon Sequestration: Can We Afford It?" The free talk is at 7 p.m. on Monday, Feb. 29, at Centennial Hall, 1020 E. University Blvd. This is a lightly edited transcript from Ogden's recent appearance on Zona Politics with Jim Nintzel.

You do a lot of work with biofuels such as algae. Tell us a little bit about how that works and where the resource is at this point. At the UA, I lead up a program that's a collaboration with one of the government labs, specifically Northwest Labs and New Mexico State University and Texas A&M. The UA is the lead institution and our goal right now for the research is to understand if we can grow algae or cultivate algae outside, 24-7, 365 days a year to be able to make fuel. The Department of Energy is our funding source for that. And if you don't want to make fuel when oil is only $30 a barrel, such as it is right now, you can also use the algae to make food.

How do you make fuel out of algae? So when you take an algae cell, you grow it up and it's a lot more dense than like what you'd have in your swimming pool, but you still have a lot of water with it. You have to separate the water from the biomass and then you take the biomass and you can either convert all of the biomass into a fuel, or you could separate it, and you could take the protein part and do something else for protein with it, and take the sap or the lipids and turn that part into fuel only. And you have algae beds at the campus farms up there on Campbell Avenue and Roger Road? Yes, correct. They're kind of past the greenhouses. They're hidden a little bit, which is okay. They're a little bit out of the way. And how far along is this technology in terms of being able to produce a lot of fuel from algae? So, there's been a lot of push since around 2009, which is when people started to invest in it again. That's when oil was really costly, and there was quite a bit of investment in it, and I think since 2009 to about now we've brought the cost down of making fuel from, like, hundreds of dollars a gallon to $7 to $10 a gallon, so it's getting closer to reality. That's tough to compete with a $1.50 a gallon of gas. Yes, of course it is. It is. But we're getting closer. From $200 to $7 is not so bad. That's a good jump right there. What got you interested in being a chemical engineer and in particular this field of study? When I was in high school, I didn't know what engineering was. A lot of kids don't. And math was pretty easy for me, so when I got to college I just tried it out. I kind of like fell into it, and I think the reason that I stayed with it was because I always had really good mentors. It was all about someone that really mentored me and said, "You know you can do this. You can do whatever you want. And then you can go to graduate school and try whatever you want." And then I just kind of got interested in the bio aspects of it, so I do I've done a lot of bioreactors throughout my career—reactors to make pharmaceutical products, to clean up waste streams and now to make fuel. That's what I do. Kind of a reactor person

The title of your talk is "Carbon Sequestration: Can We Afford It?" What is carbon sequestration? So there are a lot of different ways that people have thought about trying to take carbon out of the atmosphere in some way. And most of the carbon dioxide that we make today comes out of power plants or, like, cement plants. What people would like to do, one of the technologies, is essentially take what comes out of the top of the power plant and concentrate the carbon dioxide and then pump it underground. They're kind of sequestering it way deep in the earth, and leaving it there. That's one option. And the second part of your talk title is "Can we afford it?" So, can we afford to do this? It depends on how much you want to pay to do something like this. So the problem was pumping carbon dioxide underground is it's kind of costly. So it would probably, just to pump the carbon dioxide underground, it would increase our utility bills by 20 or 30 percent. We would need 20 percent or 30 percent more energy just to take the CO2 underground. Then we'd all be paying that much more in our utilities.

What about solar energy as a viable alternative? The use is growing but it still represents a tiny fraction of what we use here in the United States. I don't think there's one answer for our energy future. We want to use a suite of clean technologies in the future. You know, battery-powered cars and things like that, and switching from coal to natural gas. They're not going to use solar in Alaska in the winter, right, but solar in Tucson is a really good idea most of the time. So, in sunny climates and so forth where solar has a lot of potential. The challenge is balancing things with solar for the power companies. The power companies have to be able to balance, when you've got solar energy or wind energy and then when you don't have it, but you have to make it up with other electricity, and there's a lot research in grid management and things, and Tucson Electric Power is great, they're really working with the university, working with the city and everybody else to put more solar in our system, on our grid. What about nuclear energy? There's a lot of nuclear promise. The scare, of course, about nuclear is, you know, when you have a tsunami or whatever, what a nightmare. Or Chernobyl. You know those are nightmares. But the technology is getting better and better and safer. Idaho National Labs is one of the groups that like these modular nuclear reactors, now. They're small, depending on how much you need. You can stack them together and they're a lot safer, and they understand them a lot more. And—Arizona has the Palo Verde plant, and it's running safe. It can't discharge anything, so they recycle and re-use their water and everything within that facility. So we've made a lot of progress to make nuclear a lot safer. There's still always going to be a waste-disposal issue.

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