A BRIEF THERMODYNAMIC ANALYSIS OF THE PHOTOSYNTHESIS PROCESS

Increased atmospheric carbon dioxide concentration has led to a global environmental focus on methods to capture and reduce this gas. One route is to consider biological systems, since they are capable of reducing carbon dioxide by photosynthesis. The benefit of this process is its reliance on light energy from the sun – a “free”, long-lasting energy source. The photosynthetic reaction is analysed thermodynamically, at ambient temperature, to establish photon requirements relative to carbon dioxide uptake and carbohydrate production. By looking at the energy and entropy balances, and the change in Gibbs Free Energy across this reaction (ΔGrxn), necessary photon amounts are calculated at different wavelengths.