The introduction of increasingly strict rules related to the processing and storage of animal waste, the growing demand for energy and the creation of sustainable animal husbandry have led to an increased interest in the production of clean energy from animal waste. The production of biogas and its subsequent burning on the farm is among the most promising technologies. One of the possibilities for the utilization of biogas is through the use of small aggregates for the combined production of electricity and heat energy based on an internal combustion engine. Analysis of such facilities that have been put into operation show that alternative technologies using biogas as fuel are better than conventional options, both from an economic and an environmental point of view. In this sense, however, the introduction of such a technology into operation is always associated with a number of risks, since investments in new technologies are influenced by technical and economic uncertainty. When planning and preparing the plan for the construction of such a biogas facility, the investment costs, technical support and profitability of the project are essential. Introducing critical economic and technical parameters to inform the farmer of all possible investments, operational and unforeseen risks will allow him to accept the challenges and choose the best solution for his farm. In this publication, an analysis and assessment of the risk has been carried out based on the characteristics of the technology – the possible consequences of the risk are also presented. A risk matrix related to the specifics of the object and the technology is proposed, with the help of which, the type of risk is identified. Based on an analysis of the obtained results, a motivated proposal for reducing the risk is made.

The economical combustion of gas fuel implies that it takes place with a minimum coefficient of excess air and minimal losses. Constructive, aerodynamic and physical factors have a determining influence on the completeness of combustion and the conditions of ignition. Using the ANSYS software program, the main characteristics of the combustion process in the cylindrical mixing section of a flat flame injection burner are investigated through computer simulation. A geometric model was created on which it is possible to study both straight and rotating jets. The possibility of numerically investigating the combustion of gaseous fuel (C ₃H ₈) in a confined air flow produced by injection is considered. A k-ε model of turbulence was used, which is based on the equation for turbulent kinetic energy and its dissipation rate. The purpose of the work is to study and analyze the changes and distribution of temperature and speed as well as the concentration of nitrogen oxides and carbon monoxide along the axis of the combustion chamber. The results are presented for the angles of inclination of the nozzles of 45° and 0°. Based on these, an analysis was made, where it was found that with the increase in the degree of rotation, the absolute values of the temperature increase and the change in the mass concentration of the fuel along the length of the mixing section can be used to regulate the combustion process. The created numerical model can be successfully used to determine the main parameters of the burner under the same initial conditions, changing the angle of inclination of the nozzles. The obtained results can be considered as a basis for further research related to increasing the efficiency of the combustion process and lowering the harmful emissions produced by it.

As a result of the development of industrial organic synthesis, the output of secondary processes in oil processing is becoming increasingly diverse. Production volume is a nodal indicator that is limited by the available production capacity, equipment configuration and the monetary equivalent of energy costs. In order to determine the technological potential and cost of produced petroleum products, it is necessary to create a complex that includes all stages of production. The most important criterion for evaluating the energy efficiency of an oil refinery is the relative energy consumption, which depends on its complexity. This criterion can be presented as a set of the different types of energy resources used in the course of production and applied to the total production. For this purpose, the energy resources invested in the given technology should be referred to a finished product or raw material. The peculiarity of oil refineries is that, due to the variety of oil derivatives, energy consumption, as a set of different installations, is much more appropriate to relate not to individual target products but to the amount of processed oil. In practice, all types of energy carriers must be converted to an equivalent value. This paper provides an in-depth analysis of the energy costs of oil refineries. The collection of energy flows of different types and dimensions is the subject of the present study. Based on this, a method is presented that allows a comparison of the energy efficiency of refineries with different capacity and configuration of crude oil processing stages based on the energy index and the equivalent distillation performance.