Probably the most absurd “green” technology yet proposed by DECC to “tackle” climate change are biofuels. Biofuels are either ethanol based derived from sugar cane and corn or biodiesel derived from palm oils and rape seed oils. The first can be added to petrol and the second to diesel. The UK government is subsidizing these biofuels through the “Renewable Transport Fuel Obligation” which “requires” the UK to use 5% of biofuel. This is supposedly to reduce carbon emissions. However a proper scientific analysis demonstrates this is total nonsense. This absurd policy directly increases world food prices thereby starving the poor to reward the rich. In reality the conversion of fossil fuel energy into food has saved humanity from global famine because fertilizers are 100% based on petroleum products. To quote some passages from a definitive (IMHO) US navy report (author: T. A. “Ike” Kiefer).
Without the addition of artificial fertilizer energy, plants are limited to getting their energy from the sun. The devastating limiting factor for all biofuels is that photosynthesis captures solar energy with surprisingly poor speed and efficiency—only about 0.1 percent of sunlight is trans-lated into biomass by the typical terrestrial plant, and this translates into an anemic power density of only 0.3 watts per square meter (W/m2). This is 20 times worse than the 6.0 W/m2 that current solar panels arrayed in large farms can collect from the same sunlight and acreage. Humans must input fossil fuel energy in the form of ammonia fertilizers to overcome this solar limit on biomass production for crops. While this is a justifiable option to increase food production, it makes no sense to add energy to something that is supposed to be an energy source such as biofuel crops. It is also nonsensical to add fossil fuel energy when the objective is to displace fossil fuel energy.
A perfect combustion fuel possesses the desirable characteristics of easy storage and transport, inertness and low toxicity for safe handling, measured and adjustable volatility for easy mixing with air, stability across a broad range of environmental temperatures and pressures, and high energy density. Because of sweeping advantages across all these parameters, liquid hydrocarbons have risen to dominate the global economy. The effectiveness of a fuel is measured by its “Energy Return on Investment” or EROI.
A study of historical US economic performance over the last century has found that economic recessions are linked to primary energy EROIs dipping below a critical threshold of 6:1.21 This value represents the minimum energy quality an industrial civilization must have to sustain a modern, energy-intensive quality of life.
Over the past 70 years, the United States has nearly perfected corn as a high-yield food and industrial starch feedstock. Unfortunately, the laws of physics exact large energy tolls from processes that require many conversions, such as producing liquid fuels from solid biomass. After decades of study and experimentation and continuously refined commercial production, the scientific literature consensus for corn ethanol EROI is a lowly value of 1.25:1. Even worse, there is no net gain in liquid fuel energy—the ethanol produced contains energy barely equal to the input fossil fuel energy. The small energy profit is contained in byproducts, principally high-protein biorefinery leftovers called distillers’ dry grains and solubles (DDGS) that can be used as cattle feed. Plant species which yield some biomass as lipids include soy, cam-elina, rapeseed, oil palm, jatropha, peanut, sunflower, cottonseed, saf- flower, and microalgae. Contrary to popular belief, biodiesel is a very different chemical cocktail than conventional diesel fuel and has a lower energy density and inferior physical properties. To overcome biodiesel and other liquid biofuel shortcomings and make them more compatible with existing fuel infrastructure and high-performance engines, they must be transformed into true “drop-in” hydrocarbons by a series of processes, known as “hydrotreating,” that increase the ratio of hydrogen to carbon, remove all oxygen, and change the structure and blend of the constituent molecules.38 Hydrotreatment greatly increases the cost and reduces the renewable nature of the fuel, because the hydrogen added comes from fossil-fuel natural gas and the process releases 11 tons of CO2 for every ton of hydrogen added.
The simple but decisive math is that, even at commercial scale with generous assumptions about cellular reproduction rate and lipid fraction and oil extraction, and ignoring the costs of facilities and water, Argonne National Laboratory has calculated that it takes 12 times as much total energy and 2.6 times as much fossil fuel energy to put a gallon of algae biodiesel in a gas station pump instead of a gallon of petroleum diesel— and this is before hydrotreatment.
Fossil fuels provide the farm machinery fuel and processing plant heat and electricity used to make biofuels from biomass. Petroleum and natural gas are also the feedstock for the massive organic chemical industry that makes the herbicides and pesticides applied to biofuel crops and the designer enzymes used in the latest high-technology approaches. The energy to prepare the giant yeast and microbe cultures that ferment the sugars into alcohol and the immense heat needed to distill the 4 percent alcohol beer into 99.5 percent pure anhydrous ethanol are overwhelmingly supplied by fossil fuel. Of course the energy used to build the biorefineries in the first place and to transport the final product to market is largely from fossil fuel as well.
Some might argue that all of the above is only true because biofuels have not yet gained enough of a market share to provide these energies. However, the truth is that biofuels have been around for a century (the first US commercial cellulosic ethanol plant was opened in 1910) but have failed to gain market share because they are a poor energy investment. They are crippled by the thermodynamic energy losses of all the transformations involved from making a low-energy-density, solid carbohydrate into a high-energy-density, liquid hydrocarbon. If they were used to provide the energy for their own manufacture, or even allowed to compete with- out subsidies, there would be little if anything profitable left at the end to market. Without petroleum or a replacement source for massive quantities of hydrogen to make ammonia, all biomass yields, particularly food, will plummet toward what they were before Haber’s monumental discovery in 1909, with devastating consequences for the world.
Accelerating the use of petroleum by using it to make biofuels accelerates future scarcity, undermines international food security, is counterproductive to “green” energy goals, and is not sound energy strategy.
Current biofuel policy pays subsidies to the rich at the expense of the world’s poor. It encourages the destruction of rain forests across Borneo to Brazil and increases net energy costs to no avail whatsoever. This crazy policy violates the 2nd law of thermodynamics by purporting to be some sort of “green” perpetual motion machine. It is precisely complete & utter nonsense !