SOME THERMODYNAMIC REMARKS ON PHOTOSYNTHETIC ENERGY-CONVERSION

A green plant can be viewed as a control volume in which exergy from s olar radiation is converted into the exergy of photosynthetic products . Even today, great portions of the world's exergy requirements come f rom biomass. Thus, after some considerations about the exergy value of black radiation and of solar energy, the main purpose of this paper i s an analysis of the thermodynamic efficiency of photosynthesis, subdi viding the whole process into various phases, in every one of which th e relative entropy production and exergy efficiency are examined. In a ddition, with reference to some recent papers, remarks are reported ab out the difference of photosynthetic conversion between cultivated cro ps and natural ecosystems. (C) 1998 Elsevier Science Ltd. All rights r eserved.