Artigo fuelbio fossil

Fossil fuels, like mineral oil, coal, and natural gas, are derived from the biomass of ancient times. As such, they are indirect products of photosynthesis. It is therefore appropriate to ask whether we can use currently available biomass and convert it into biofuels like biodiesel and biogas. Biohydrogen might be another option. Often one can read that biofuels are CO2-neutral and therefore a weapon against global warming. Their production is also supposed to reduce the amount of petrol and natural gas to be imported into many countries, thus making them less dependent on energy import. In the following, I shall discuss the efficiencies of the processes required to produce biofuels, compare them with alternatives, draw the obvious conclusions, and present some visions.
First it is necessary to discuss the efficiency of photosynthesis and to present some ideas on how to improve photosynthesis and therefore enhance biomass production. Photosynthesis comprises so-called light reactions and dark reactions. In the light reactions, the light is absorbed by the photosynthetic pigments and the energy is transferred to the reaction centers where the primary charge separation and a transmembrane transport of electrons takes place. Subsequent electron- and proton-transfer reactions lead to the synthesis of the universal biological energy carrier ATP from ADP and inorganic phosphate, and NADP+ is reduced to NADPH. In the following dark reactions, NADPH and ATP are used to take carbon dioxide from the atmosphere and use it for the synthesis of carbohydrates.
The photosynthetic pigments of plants can only absorb and use 47 % (related to energy) of the light of the sun (“photosynthetic active radiation”). Green light, UV, and IR irradiation are not used. In theory, 8 photons are required to reduce 2 molecules of NADP+ to NADPH, in reality, 9.4 photons are found to be necessary for this purpose. Knowing the average energy of the photons and the energy stored in the form of