The application of microalgae biomass of Chlorella sorokiniana as environmentally friendly biosorbents for removing potentially toxic elements (PTE) from water and as a source of biofuel has been thoroughly studied. In this paper, we investigate its physicochemical properties infrared spectroscopy (IR spectra), microstructure, adsorption properties); we have managed to isolate the lipid complex, which amounted to 20% of dry biomass. Studies of the lipid complex showed that 80.02% of lipids are unsaturated fatty acids (C18:1, C18:2, C18:3). Additionally, we have investigated the efficiency of using the residual biomass obtained after lipid extraction for water purification from rare-earth metals (REM) and PTE. To increase the sorption properties of residual biomass, its thermal modification was carried out and sorption materials based on heat-treated residual biomass and chitosan were created. The physicochemical and mechanical properties of the obtained sorption materials were studied. The total sorption capacity was 31.9 mg/g for REM and 349.7 mg/g for PTE. Moreover, we propose a new method for the disposal of spent sorbents as additional fuel. Spent sorbents can be considered to be biofuel in terms of energy content (20.7 MJ*kg−1). The results of this study provide the basis for increased use of microalgae.

Microalgae have attracted growing interest all around the world due to their potential applications in multiple sectors of industry, such as energetics, nutraceuticals, pharmaceuticals, agriculture, and ecology. Concepts of biorefinery of microalgae lipids for biodiesel production coupled with other applications have been suggested in several studies. However, very few studies focus on overcoming the degree of unsaturation of microalgae lipids using methods of fractionation. This study presents a method for obtaining two oil fractions from microalgae Chlorella sorokiniana suitable for food and biofuels via urea complex formation with further production of a long-chain PUFA concentrated oil suitable for the nutraceutical industry. A DHA–EPA-rich fraction was obtained from the dry microalga biomass using a succession of extraction, urea-complexation, fractionation, and esterification with glycerol. Analytical and organoleptic methods were used to assess the quality of the final product. Results show that the urea-complexation method allowed the obtaining of two lipid fractions with different fatty acid profiles. The urea complexed fraction (UCF) contained a majority of saturated fatty acids (54.46%); thus, it could find applications in the biofuels or food industry. The non-urea complexed fraction (NUCF) was rich in polyunsaturated fatty acids (PUFA) (81.00%), especially long-chain PUFA with 16.52% EPA and 35.08% DHA. The recovery rates of EPA and DHA in the NUCF reached 59% and 87.14%, respectively. Finally, the physicochemical and organoleptic characteristics of the DHA–EPA oil concentrate were determined and found conform to the norms recommended by the WHO/FAO standards for edible oils and the Russian State Standard GOST 1129-2013.

This work makes it possible to link ground rules for thermal and electrical energy markets with generation plant operating. Here we consider various procedures for optimization of combined heat and power plant operating mode by means of underutilized equipment mothball. This work results in process flow diagrams for turbine hall and relative increment charts, which can be used for plant loading in the optimal way.

Nowadays in Russia we see rapid modernization of power engineering and transport systems. Under these conditions the issue concerning improvement of regional heat supply system energy-efficiency has gained a new importance. The aim of this study is to find new development directions of the public-private partnership (PPP), specifically from the perspective of its energy efficiency. Amid the financial crisis and economic sanctions the formation of public-private partnership allows increasing of energy efficiency of regional fuel and energy complex by means of regional energy service company creation. This paper will be useful both for central and local government and for private business.

This work presents a complex of technological solutions aimed at possible improvement of performance efficiency of oil refinery plants. These technological solutions are based on the control mechanisms of consumer material-heat balance for obtaining an optimum balance between fractionating accuracy of the obtained distillates, process energy characteristics and increase of the thermal energy integration at the plant. At this the proposed solutions do not provide the changes of the basic plant equipment, and no significant capital investments should be made for its implementation.