The biodiesel fuel synthesis process is implemented in a batch plant by the transesterification of shea (Karite) and palm oils in an ethanol medium under supercritical fluid conditions in the temperature range 623–673 K and an alcohol-to-oil molar ratio range of 30 to 42 at a pressure of 30 MPa for 30 min. Data on the determination of the kinematic viscosity and composition of the resulting products and the feedstock conversion are obtained; and the optimal reaction conditions are found.

Photosynthesis is considered to be one of the promising areas of cheap and environmentally friendly energy. Photosynthesis involves the process of water oxidation with the formation of molecular oxygen and hydrogen as byproducts. The aim of the present article is to review the energy (light) phase of photosynthesis based on the published X-ray studies of photosystems I and II (PS-I and PS-II). Using modern ideas about semiconductors and biological semiconductor structures, the mechanisms of H⁺, O₂↑, e⁻ generation from water are described. At the initial stage, PS II produces hydrogen peroxide from water as a result of the photoenzymatic reaction, which is oxidized in the active center of PS-II on the Mn₄CaO₅ cluster to form O₂↑, H⁺, e⁻. Mn⁴⁺ is reduced to Mn²⁺ and then oxidized to Mn⁴⁺ with the transfer of reducing the equivalents of PS-I. The electrons formed are transported to PS-I (P 700), where the electrochemical reaction of water decomposition takes place in a two-electrode electrolysis system with the formation of gaseous oxygen and hydrogen. The proposed functioning mechanisms of PS-I and PS-II can be used in the development of environmentally friendly technologies for the production of molecular hydrogen.

Rapeseed oil transesterification reaction with ethanol under supercritical fluid conditions was performed either in the presence of catalysts or without them. The catalysts were Al₂O₃ and AlOOH, obtained after Al₂O₃ hydrothermal processing, and CaO/Al₂O₃ and CaO/AlOOH, obtained after permeation. The obtained product was measured for dynamic viscosity and density. Based on these data, kinematic viscosity was calculated. Biodiesel fuel was separated via centrifugation to extract more viscous ethyl esters of saturated fatty acids and unreacted triglycerides in order to comply with the standards for biodiesel fuel. Analyses have found that the maximum content of obtained ethyl esters of fatty acids in a reaction product before separation is reached, in the case of using the CaO/AlOOH catalyst, is in the amount of 93.34% by mass; and none of the samples’ kinematic viscosity values comply with the standards for biodiesel fuel. Performing centrifugation allowed us to reduce viscosity and increase biodiesel fuel concentration to reach the EN14214 standard requirements. Also, a significant deterioration of the initial catalysts’ strength after the singular experiment has been observed: Al₂O₃ by 22.4%, AlOOH by 13.89%, CaO/Al₂O₃ by 25.13%, and CaO/AlOOH by 17.27%.

The involvement of natural radicals in single-electron processes of cell activity is considered. It was shown that coenzymes that have intermediate free radical quinoid and semichinoid forms can interact with carotenoids to form complexes with a charge transfer with an absorption band of 1030 nm. Moreover, the complex can perform an active light-harvesting function during photosynthesis up to 1100 nm, with the energy transfer from chlorophylls a and b to the complex. Studies of the sorption of the alcoholdehydrogenase–nicotinamide adenine dinucleotide enzyme–cofactor system on a hydrophobic electrically conductive carrier showed that the activity of the enzyme–cofactor system is at its maximum for sequential sorption of the coenzyme and then the apoenzyme. The orientation of the biocatalytic system on the immobilization matrix is of great importance.

Four enzymatic complexes form the electron transport chain of the mitochondrion. Complexes I and II are current generator half-elements, that create electron flows with the participation of the enzymes NADH dehydrogenase and Succinate dehydrogenase, oxidizing NADH·H into NAD+, and succinate into fumarate, respectively. Electrons are transferred throw the iron-sulfur clusters system, participate reduction enzymatic reaction of CoQ10 into CoQ10Н2. The proton pumping into the mitochondrial intermembrane space, as well as the regeneration of CoQ10 occur when electrons transferred by ubiquinone-cytochrome-c-oxidoreductase enzyme to the Riske iron-sulfur protein (Fe2S2). The Riske protein regulates electron flows: it transfers one electron to the bL,bН (III) complex, and the other to cytochrome c. Cytochrome c directs electrons to the ΙV complex electrolysis system. The binuclear copper center [CuA-CuB] of the ΙV complex is the anode, where oxygen is formed. Electrons along the galvanic pair chain from paired copper Cu2++ e- ↔ Cu+ and iron Fe2+- е- ↔Fe3+ are transferred to the cathode, copper ion (Сu+), where the electrochemical reaction occurs O2 + 4e- + 4H+ → 2H2O, with the pumping of 4 protons into the mitochondrial intermembrane space.

The article examines the energetic processes of the light‐dependent phase of photosynthesis. It explores the nature of energy and charge transport in molecules containing isoprene and isoprenyl bonds. A mechanism is proposed for the operation of a quantum current generator—Mn ₄ O ₅ Ca(Н ₂ О) ₄ proceeding through the formation of electron–hole pairs. The study explains the mechanisms of hydrogen peroxide formation in PS‐II and its role as an intermediate energy carrier in the light phase of photosynthesis. The role and operating principles of P680 (PS‐II) and P700 (PS‐I) are described as natural photoelectrolyzers that function to remove excess electrons from chloroplasts. Furthermore, the operation of the proton molecular pump (Q‐cycle) and the photosupercapacitor the В ₆ f complex is explained. Within the electron transport chain, molecular electronic systems that monitor and control light‐dependent redox reactions.