EGEE 439
Alternative Fuels from Biomass Sources

1.1 Why Biofuels?

The following video is a debate between me and Dr. Jonathan Mathews regarding some questions people have about using alternative fuels from biomass. I co-teach another course with Dr. Mathews, EGEE 411, and he has a much different perspective on the use of biofuels. We've known each other for a long time and tend to have this discussion over and over again. Most of the points brought up during our debate will be discussed in various parts of the course. It may also be useful to look at the debate as a way to critically think about the use of biofuels. There will be discussion questions throughout the semester to challenge you to look at the use of biofuels and to push you to think about the facts, not just what people say (6:40).


Click for transcript of the biofuels debate video.

Biofuels Debate Between Caroline Clifford and Jonathan Mathews

CAROLINE CLIFFORD: Hello, I'm Caroline Clifford. I'm about to have you embark on a new experience with the online class you're about to take. I teach in energy and mineral engineering, but I also teach classes in Ag sciences, and my research is involved with coal and biomass conversion to liquid fuels.

JONATHAN MATHEWS: I'm Jonathan Mathews, an associate professor in energy and mineral engineering. I teach energy engineering with my colleague Dr. Clifford, and I also do engage in coal research.

Question printed on screen: Some people say that the amount of energy required to produce ethanol is greater than the amount of energy actually yielded by the fuel when used in vehicles. Is this true?

JONATHAN MATHEWS: So the ethanol question is interesting. It comes down to location and source. Sugarcane-derived ethanol is actually very useful. It's much easier to process, it has a much greater energy content and it doesn't require the same inputs. Corn-derived ethanol however is more challenging. It certainly makes sense in the Midwest, however it doesn't make a lot of sense if you make it in the Midwest and ship it all over the United States forcing it into existing gasoline supplies. So the problem with ethanol derived by corn is it's a less efficient process. You get much less ethanol and also they're challenges with fertilizer and shipping costs.

CAROLINE CLIFFORD: Well, I agree with most of your assessment Dr. Mathews. But with corn ethanol, it has come a long way in that it is improving with its net energy benefit ratio. If you have a net energy benefit ratio that is less than one, you have a big problem. And now that energy benefit ratio of ethanol from corn is about one and a half to two. Part of the reason behind that is because they have been using biomass as part of the processing along with coal to try to reduce the coal issues in the atmosphere. I will be explaining the net energy benefit ratio later on in this semester.

Question printed on screen: Is ethanol harmful to cars and trucks?

JONATHAN MATHEWS: So there's a significant challenge in firing pure ethanol. It's mitigated by blending it with gasoline. So typically, when I buy gasoline it may have up to 10% ethanol by volume. Ethanol is slightly corrosive to some of the metal components and it also dissolves and attacks some of the rubber components in the seals in the engine, so that it is troublesome. But blended-in, mostly with the modern vehicle, you should be fine.

CAROLINE CLIFFORD: Some of the issue with using ethanol-- again from the perspective of Dr. Mathews-- 100% could be damaging to your vehicle. In some of the older vehicles, even when blended with gasoline, there was an issue with it damaging some of the seals that were involved and being corrosive to some of the metals. However, recently the car manufacturers have accounted for this. And they have made cars that are specifically designed so that you can have ethanol in your sample. And as far as using ethanol in vehicles, we are currently in this country using 10% of our fuel as ethanol.

Question printed on screen: Can jet fuel be made from biomass? The energy density of ethanol is low, so what would be used?

JONATHAN MATHEWS: So we could certainly make biodiesel from biomass, and jet fuel would be a smaller chain hydrocarbon. So with processing, that's certainly possible. However, it's probably much easier just to get this from distilling crude oil and going through the usual routes or even going through a gasification route with coal to make synthesis gas and produce jet fuel from that process. So can it be done? Yes. It certainly wouldn't be ethanol. Energy density is too low. It has handling problems with cold temperatures that would be required. So you need very different molecules in jet fuel.

CAROLINE CLIFFORD: Again, I agree with Dr. Mathews from the perspective of ethanol is not a very good fuel to use for jet fuel. And that there is the option of biodiesel, but biodiesel does have a problem in that it has a certain chemical structure in it that you have to minimize for jet fuel because it can cause problems with making the fuel gum up. However, refineries and biomass refiners are looking at ways to try to introduce materials into a refinery in order to make a jet fuel that would be usable and would not have to go through the process of doing gasification and then Fischer-Tropsch synthesis in order to make a jet fuel.

JONATHAN MATHEWS: So this jet fuel from biomass, quite frankly, is stupid.

CAROLINE CLIFFORD: Why do you think it's stupid Dr. Mathews? I totally disagree with you.

JONATHAN MATHEWS: We get jet fuel perfectly well from existing infrastructure. We can get it from crude oil. There's a possibility of making it from natural gas which we have an abundance of right now. We can even do it from coal which would be lovely. Why bother with biomass?

CAROLINE CLIFFORD: Because biomass has the advantage of being CO2 neutral or at least is almost CO2 neutral. And if we're looking to make changes in our environment, trying to use something other than petroleum or natural gas or coal, which are all fossil fuels, would be beneficial. And we might be able to grow our own and not have to worry if there's any energy security issues.

JONATHAN MATHEWS: So what you want to do is replace nice, cheap jet fuel with really, really, really expensive biomass and only the rich can fly. Shame on you.

CAROLINE CLIFFORD: Oh my goodness Dr. Mathews, stop it. You know better than that.

JONATHAN MATHEWS: Well, it's true. Fossil fuels are cheap, and it's excellent and it helps the world.

CAROLINE CLIFFORD: Well, the fossil fuels being cheap have caused the problems to begin with. So we need to do something to mitigate the problems that have been caused by fossil fuels and putting too much CO2 into the atmosphere.

JONATHAN MATHEWS: Fine. So coal is absolutely fabulous. And all this talk about anti-coal is silly. Let me tell you what coal does. Coal is cheap. It gives you guaranteed available electricity, something the renewables struggle with-- with the exception of hydro-- and also it enables the economy to move forward. So if want to start moving over to this green economy and having all these bloody renewables, be prepared to pay a lot more for it. And just because it's renewable doesn't mean it’s free.

CAROLINE CLIFFORD: From the experience that I have been dealing with in converting coal and biomass to liquid fuels, I think that biomass has a greater opportunity in the long run. And it is because of the environment. That doesn't mean getting rid of all fossil fuels. It means trying to find a way to utilize both and to find a way to make it cheaper to make the biofuel. That's where we're going with that.

As you can see, not everyone thinks that using biofuels is a good direction to go. Some may not see the big picture - that future energy demand world-wide will require everything we can get our hands on - or may only see the negatives of biofuel production. Or people may be misinformed. Part of the purpose of the course is to help you to understand why biofuels are needed and how to make them, at the current state-of-the-art.

Why biofuels? To look at the situation a little more broadly, the question then becomes: why alternative fuels?

There are three main reasons to develop alternative fuels:

  1. to meet the needs of increasing energy demand;
  2. dependence on foreign fuel sources can be problematic, depending on US domestic fuel production;
  3. to reduce greenhouse gas (GHG) emissions.

We will explore each of these reasons in more depth in the following sections.