Rehabilitating Bio-Fuels Part 2: Interesting Second Generation Options
My previous post retraced the precipitous decline in the reputation of biofuels that occurred between 2006 and today. In this post I’m going to talk about just a few of the activities going on for “second generation” biofuels (beyond corn, soy and palm oil, wheat…). One of the key features of these initiatives is that they reduce the competition with food crops – something which will only become a more significant issue in the future. I’ll be talking about several Universities and companies who have hung in there through the ups and downs of oil prices and the “trendiness” and “rejection” of biofuels. I think that these folks are going to make significant long-term contributions. If you have been soured in the past on the biofuel concept, please consider these alternatives.
There was a recent Wall Street Journal article about “5 Technologies that could change everything.” One they included was biofuels from Algae. People have been working on this for a long time including a very long government effort. The great thing about algae is that you can grow it in places and with water sources that are completely unsuitable for farming. Algae can be extremely productive. The problem is that the low capital investment systems are less productive and the highly productive, “bio-reactor” approach has a huge capital cost. The good news is that there are enough companies working away on this that sooner or later there might be a break-through. I won’t pretend to be an expert on how this is going, but I have a hunch it will eventually become significant.
Biofuel Grows on Trees (or at least it can)
Wood has been the world’s dominant biofuel for millennia, but there are some really cool things going on in that arena today. The advantages of trees are that they can be grown on land that isn’t suitable for food crops, they are great for biodiversity (particularly if grown with the sort of comprehensive landscape management plan employed by progressive timber companies today). Trees also provide their own “storage” of the biomass. That is an advantage over an annual crop has to be harvested over a fairly narrow window and stored for use in a biofuel production facility through the rest of the year. Also, trees don’t require much if any nitrogen fertilization so they don’t produce nitrous oxide emissions above natural levels for soils.
The great thing for the US is that there are vast areas in the American Southeast that have the rainfall and heat to grow these forest crops. If a forest plot in that area is allowed to regenerate on its own after harvest it generates 0.5 dry tons/acre/year of new biomass. With the sort of improved tree lines that are available today that can rise to 6-8 tons. For example, the forestry company, Arborgen produces 275 million improved tree seedlings a year that have that sort of yield potential. With future biotech lines for pines or Arborgen’s frost tolerant Eucalyptus, Arborgen estimates that it will be able to produce wood on the order of 18-23 dry tons/acre/year. That would be enough to generate 1,800-2,300 gallons of cellulosic ethanol/acre/year. Arborgen has recently entered into a partnership with a bio-energy collaborative centered at Clemson University and involving several other companies that play different roles in the bio-energy process. There are interesting groups around the country working on other tree species for different climates like the Tree Bio-safety and Genomics Research Cooperative associated with Oregon State University, and there are other major tree genetics companies like Cellfor that supply improved tree seedlings on a major scale. There is a lot of good stuff happening in this field, far more than I can adequately describe in this post.
Perennial C4 Grasses
Switchgrass and Miscanthus are other perennial crops that have gotten a great deal of investment over the years and most recently by companies like Mendel and Ceres. I don’t want to short-change those crops because there has been some really great progress here. These players have also engaged in the development of other very interesting options like the annual crop, fiber sorghum which is also well suited for low food crop productivity areas. Exactly where and how these grasses will be grown is will determine just how positive contribution they will make. These grasses will certainly play a role in the future of biofuels.
A less well-known biofuel crop is the “Tropical Sugar-beet.” This crop was developed by a breeder for the global company, Syngenta, over more than a decade. It is now an amazingly productive crop that can be used for either food sugar or ethanol. It was developed for Asia, but it can grow in some parts of the Southern US. It does not need advances in conversion of cellulose to sugar that are required by many other cellulosic sources. Tropical sugarbeet is currently being developed in India, but it has a limiting factor in the US that is absurd. There has been such a big marketing push for “Cane sugar” as an alternative to “high fructose corn syrup” that beet sugar (which is exactly the same as cane) has been made to be “brand unfriendly” for food companies. This is just dumb. The great thing about a crop like Tropical Sugar Beet is that it can supply either the food or the fuel market, depending on the price. That makes it a more attractive crop for a biofuel producer.
So, my conclusion is that environmentally conscious folks need to re-visit their opinions about biofuels. There are some very interesting options which don’t have the food vs fuel issues of the first generation. We should probably also remember that for these crops, or even for a crop like corn, the details of how it is grown are key to whether it is a really good thing for the world or not. It takes a full life cycle analysis (LCA) to tell. Let’s not give up on the idea that we can use plants to harvest solar energy.
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Conifer planting image from USFS Region 5