Biofuels – Just One Component Of A Long Term Solution

Biofuels are fuels such as bioethanol, biobutanol or biodiesel made from plant or less commonly animal material or food waste. Bioethanol and biobutanol are typically used to reduce the amount of gasoline used while biodiesel is used to lower the amount of diesel fuel used. Although the first generation biofuels are not economically viable, second generation biofuels should be more economically attractive and thus part of a strategy to reduce long term our dependence on fossil fuel.

First generation biofuels have not had the economic viability to compete commercially with fossil based fuel. 

 

For example, bioethanol is a rather inefficient fuel - its low energy content is approximately 76,000 BTU per gallon whereas gasoline is 115,000 BTU per gallon – and its solubility with water makes the traditional gasoline distribution infrastructure not useful. Biobutanol though has a higher energy content – 96,000 BTU per gallon - and its lack of solubility with water facilitates its use in the gasoline distribution infrastructure. But at this time, neither competes economically with gasoline. And both alcohols are typically produced commercially from corn as of now.

 

Second generation alcohols though could improve the economics and at the same time, not utilize food feedstocks. Research, which I suspect is still a long way from fruition, produces these alcohols from feedstocks such as cellulosics (wood, grass or non-edible parts of plants). Although I am not entirely sure of the following, I do believe that a major economic hurdle is the cost of the enzymes used to pre-treat the biomass material into their constituent sugars.

 

On the other hand, any biodiesel which meets the ASTM 6751 specifications will be an acceptable diesel fuel option. First generation biodiesel in the US is typically prepared from soybean oil. Any plant or animal fat that contains triglycerides can have those compounds transesterified with methanol or ethanol to successfully produce biodiesel.

 

There is substantial research being done in developing second generation biodiesel from non-food feedstocks which we have discussed in the past – algae, mustard, camelina, pennycress, jatropha and salicornia bigelovii. Some of these are also produced in an environment which would not be used for food feedstocks – a positive. All of these contain triglycerides and all can be made into an acceptable biodiesel. But economics is still the concern.

 

Another issue for these biofuels is the need to increase growth density and determine the best way to harvest and transport the feedstock to a conversion processor.

 

Short term, there are definite issues with first generation biofuels. Although they do function as a fuel, they do not have the economic viability to compete with fossil fuel. And the concerns with their overall fuel efficiency from a total life cycle analysis is something that needs to be fully and accurately addressed and then compared to a similar life cycle analysis for fossil fuel so a legitimate comparison can be made – these life cycle analyses by the way are not trivial and require a substantial understanding of the entire process.   And concerns with food competition may also be an issue. 

 

But the second generation biofuels hopefully can address these concerns successfully and we will be able to determine that success by their introduction into the market place as an economically and environmentally viable alternative to fossil fuel. One thing we do know though, although there is substantial sources of fossil fuel today (oil, natural gas and coal) at some time in the far, far future, these finite resources will be gone.

This author consults with leading institutions through GLG