“Biofuels and Biomass: Debunking the Myths and Realities”

If that of e-fuels is a foolish idea of ​​the phenomena sitting in Brussels, we must not place too much faith in bio-fuels and, in general, in energy from plant material or, even more generally, in energy from the sun (with the exception of hydroelectricity). The pretentious and sophisticated term biomass essentially corresponds to firewood, from which most of the “solar” contribution to the energy consumed in the underdeveloped world comes. Which is such precisely because it does not have access to the use of energy: what little they consume there they find available by burning the trees in their forests. It’s solar energy because it’s the sun that enables photosynthesis which, in turn, makes trees grow. These grow more slowly than they are consumed in combustion, which has given rise to the problem of deforestation.

Developed or developing countries – where other sources of energy supply are possible (fossil fuels, nuclear and hydroelectric) – make very little use of them: biomass is a primitive source, polluting and disrespectful of the environment. And it is inefficient because photosynthesis is inefficient. It can be calculated that to satisfy 10% of our electricity needs with firewood, we would have to use the entire Italian forest heritage. Over time, the idea of ​​using dedicated agriculture to grow vegetables for the production of fuel for motor vehicles: biofuels (bioethanol and biodiesel) has gained ground.

Ethanol is the common ethyl alcohol and can be used as automotive fuel; it is referred to as bioethanol when it is produced from vegetable raw material. Naturally, the plant does not spontaneously produce bioethanol: it is the final product of a complex industrial process which begins with the natural fermentation of the sugars. The idea, then, is to grow an appropriate vegetable – for example corn – to produce ethanol from it suitable for use as automotive fuel. According to the proponents, the advantage would be twofold: dependence on oil is reduced and no carbon dioxide (CO₂). In fact, even if ethanol releases CO when it burns₂ in the atmosphere, the plant – corn, in our example – will have absorbed the same amount of CO from the environment in order to grow₂. In short, whoever demonizes CO₂in the end must admit that it is the food of plants.

However, to produce an alcohol suitable as a fuel it is first of all necessary to carry out a fractional distillation on the primary fermentation product, which is an industrial process which consumes a significant amount of energy compared to the energy released by the combustion of bioethanol. Other energy is consumed in the sowing and harvesting phases, in the fertilizer production, in the distribution of the final fuel. In short, to evaluate whether or not it makes sense to produce ethanol to be used as fuel the net energy gain must also be evaluatedgiven by the difference between the energy obtained from the combustion of bioethanol minus the energy expended in the entire process, from sowing to the distribution of the finished product.

The debate as to whether bioethanol production is, in terms of net energy, a profit-making or loss-making process has involved several analysts. We are not interested in this debate because the fact is that, by accepting the most generous conditions for bioethanol compared to any analyst’s estimate, the entire Po Valley would have to be committed to maize to replace only 10% of the automotive fuel we consume. The confident look to Brazil, which replaces 25% of the automotive fuel it consumes with bioethanol (therefore 75% is ordinary fuel). They do not take into account that: 1. the Brazilian demand for fuel for motor vehicles – and, in general, for energy – is equal to that of Italy, although the Brazilian population is three times that of Italy (in short, in Brazil they are poorer than us); 2. the tropical climate makes it possible to produce ethanol from sugar cane which, for the same cultivated area, has double ethanol yields than those from corn; 3. the surface of Brazil is 30 times greater than that of Italy. At the end of the day it is like saying that if the Italian population were 2 million inhabitants, they could cultivate corn on a tenth of the surface of the peninsula and emulate Brazil.

Even the production of bioethanol from wood crops through a fermentation process of the sugars contained in the cellulose or the production of biodiesel from oil crops (soybeans, sunflower) does not promise anything amazing. In 1999 the National Research Council (NRC) American wrote: «Bio-diesel is hopeless, in the near future, to become a cost-effective fuel. In Europe, without subsidies to farmers, bio-diesel would not be competitive. And while some niche markets have been created virtually by the force of law, bio-diesel will remain too expensive to become a cost-effective fuel. It appears that the NRC’s prediction of 24 years ago was spot on.

In any case, if one asks what fraction of the total automotive fuel consumption Italy would save if all the Italian soybean crop were converted to biodiesel and if the energy expended to produce soybeans and biodiesel was zero, the sad answer is : less than 0.0001 percent.

Franco Battaglia, 29 April 2023