ANALYSIS OF THE HEAT PUMP OPERATION IN THE LOW-TEMPERATURE RECTIFICATION SYSTEM OF PROPANE-BUTANE MIXTURE

The article presents the results of the analysis of the operation of a heat pump in the system of low-temperature rectification of a propane-butane mixture. High-purity propane is obtained from a propane-butane mixture. A "rectification column-heat pump" system is proposed, which transforms the heat removed during the cooling of the component in the upper part of the column into heat absorbed during heating of the bottoms. In accordance with the energy balance of the system, it has been established that part of the heat pump condensation is not used in the distillation column, but is removed to the environment. The heat pump flow diagram contains one evaporator and two condensers. The operation of the heat pump is evaluated from the standpoint of thermodynamics – by the method of energy analysis of the cycle with R134 and R290 working substances, It has been established that the low thermodynamic efficiency of the heat pump is determined by external irreversible losses in the condensers and the evaporator The advantages of R290 as a working substance of the heat pump have been proved and the required theoretical volumetric capacity of the compressor has been determined.

Sampling and concentration of polycyclic aromatic hydrocarbons from exhaust gases from a plant for synthesis of carbon nanomaterials

Currently, there is an increase in the production of carbon nanomaterials in the world, which is associated with their unique physical and mechanical properties and their use in various fields of science, industry and technology. Investigation of the chemical composition of waste gases from a propane-butane mixture pyrolysis unit during the synthesis of carbon nanomaterials is of scientific and applied value, since it allows one to study both the chemistry of the pyrolysis process of hydrocarbon mixtures and determine the degree of toxicity of waste gas from pyrolysis units. The quantitative determination of polycyclic aromatic hydrocarbons in the gaseous products of pyrolysis of a propane-butane mixture during the synthesis of carbon nanomaterials has shown that when sampling with a small amount of the Supelpak-2 adsorbent, which is widely used in international and domestic methods, efficient capture of multinuclear aromatic hydrocarbons is not ensured. Therefore, an important research issue is the development of a simple and effective method for sampling polycyclic aromatic hydrocarbons with their subsequent GC-MS analysis. The principal essence of the technique is the impregnation of two fiberglass filters with an organic low-volatile solvent – diethylene glycol, tetraethylene glycol or dimethyl sulfoxide. The latter is characterised by the highest extracting power in relation to polycyclic aromatic hydrocarbons. The developed technique makes it possible to increase the efficiency of capturing multinuclear aromatic hydrocarbons (with four or more rings in a molecule) to 96–98 % compared to a solid adsorbent under equal conditions (pyrolysis conditions, weight of adsorbent equal with filters impregnated with a solvent), where the degree of their extraction is 1–5 %. The established values of the degree of recovery of the measured components are explained by the high extracting ability of dimethyl sulfoxide in relation to multinuclear aromatic hydrocarbons.

Multifaceted Comparison Efficiency and Emission Characteristics of Multi-Fuel Power Generator Fueled by Different Fuels and Biofuels

The negative effect of liquid and gaseous fuel combustion is toxic gases (i.e., carbon and nitrogen oxides NOx) and particulate matter (PM) formation. The content of harmful and toxic components of exhaust gases is strongly dependent on the quality and type of burnt fuel. Experimental research is required to verify the use of current technical and technological solutions for the production of electricity on farms, using various types of conventional fuels and biofuels. The aim of the current research was to comprehensively verify the use of commonly available fuels and biofuels without adapting the internal combustion engine. Gaseous fuels—propane-butane mixture (LPG), compressed natural gas (CNG) and biogas (BG)—were added to liquid fuels—methyl esters of higher fatty acids (RME) and diesel fuel (DF)—in six different power configurations to evaluate the effect on the emission of toxic gases: carbon monoxide (CO), nitric oxide (NO), nitric dioxide (NO2) and particulate matter (PM), and the efficiency of fuel conversion. The use of RME in various configurations with gaseous fuels increased the emission of oxides and reduced the emission of PM. Increasing the share of LPG and CNG significantly increased the level of NO emissions. The use of gaseous fuels reduced the efficiency of the generator, particularly in the case of co-firing with DF. For medium and high loads, the lowest decrease in efficiency was recorded for the RME configuration with BG. Taking into account the compromise between individual emissions and the configuration of RME with BG, the most advantageous approach is to use it in power generators.

Organization of transportation by tank cars of solidified petroleum fuels with transmission through field pipelines in low temperature conditions

The method of unloading and reloading solidified oil fuels, with the use of pipelines made according to temporary technological schemes, produced in winter, is considered. Cooling of solidified fuels is accompanied by a sharp increase in their viscosity, which makes pipeline transmission impossible. In fire hazard, it is proposed to produce continuous heating of the pumped fuel using devices based on low-temperature combustion of propane-butane mixture on the surface of the catalyst carried out at fire-safe temperatures. It is also proposed to install a temporary heat-insulating shell on the pipeline that meets the operating modes of the heaters.

Dobór wydajności gazów propan-butan dodawanych w celu wspomagania efektywnego spalania gazu ziemnego niskometanowego z użyciem flary

The paper discusses the problems related to the burning of gas mixtures containing flammable and non-flammable gases using a flare. Before being burned, such a gas mixture must be “enriched” with other flammable gases before it can be directed to the flare. In the case of some Polish gas reservoirs such as Cychry or Sulęcin, the composition of the gas mixture doesn’t make it possible to burn it using the flare because the content of inflammable components is too high and the gas mixture is inflammable. The gas from the reservoirs mentioned above contains above 90 percent of nitrogen and small percentages of flammable components. Sometimes, besides nitrogen, the gas mixture contains other inflammable gases like carbon dioxide, helium, and oxygen. Usually, the propane/butane is used for that purpose. The possibility of burning the gas mixture using the flare is particularly important if the toxic gases are present in the mixture – hydrogen sulfide in particular. The propane/butane gases are added to the stream of gas mixture meant for burning using a special appliance. The typical arrangement of a gas-burning installation (i.e. the flare) is shown and the destination of its components is discussed. The empirical formula is provided which allows us to recognize if the gas mixture is flammable or not. The composition of the gas mixture must be known to calculate the propane/butane flow rate, including percentages of flammable and inflammable components. The algorithm constructed for calculating the propane/butane flow rate is presented, which must be maintained to assure the flammability of the gas mixture destined for burning using the flare. The results of the calculations for four gas mixtures from the Polish gas reservoirs are provided. The presented method of determining the flammability of gas mixtures (or its inability to be burned) and the flow rate of the propane/butane mixture required for complete combustion is based on empirical relationships, which are provided in the paper and may be helpful in planning the assisted combustion of low methane gases (not suitable for further use) using a flare.

Utilization of Wood Railway Sleepers Using a Supercritical Fluid Extraction Process

In this work, we propose an alternative method for the utilization of sleepers, based on the use of a supercritical fluid extraction process. The preference for the implementation of a supercritical fluid extraction process for “extractable-extractant” systems exhibiting I–II types of phase behavior is given. On the example of supercritical fluid extraction of the impregnation material of spent wood railway sleepers, the efficiency of replacing the carbon dioxide participating as an extractant with a propane/butane mixture, which provide the desired change in the type of phase behavior in relation to such components of the impregnation material as phenol, anthracene and naphthalene is shown. The phase equilibria of thermodynamic systems involving carbon dioxide and a propane/butane mixture on the one hand and coal oil components such as phenol, anthracene, and naphthalene on the other are studied. The proposed method of processing spent railway sleepers allows you to select from it up to 97 % of the mass impregnation source material.