The article is devoted to the issues of the utilization of hydrogen-containing gas wastes in oil refining deep processing. Gas wastes consist of hydrogen, methane, ethane, propane, butane, other saturated and unsaturated C5-C7 hydrocarbons, sulfur compounds, carbon monoxide, carbon dioxide, nitrogen and oxygen. The use of a hybrid power plant for efficient conversion of the potential energy of the gas mixture into electrical and thermal energy is proposed. It is shown that gas waste from oil production has a net calorific value comparable to the calorific value of natural gas (46 and 49 MJ/kg, respectively). Fuel gas is a valuable product that can be used after desulfurization instead of burning in the atmosphere. The article proposes the developed composition of the adsorbent for hydrogen sulfide capturing, including 40% wt. bentonite, 40% wt. calcium oxide, 10% wt. zinc oxide and 10% wt. manganese oxide. The capture rate was 98.3%. A comparison of various types of fuel for a hybrid power plant with a high-temperature fuel cell and an assessment of the efficiency of using gas waste from oil refineries was carried out. It is shown that fuel gas from oil production waste has a high potential for use in power plants due to its high calorific value and a number of other advantages compared to natural gas.

The study addresses the problem of imparting electrical conductivity to conventional polymer materials for 3D printing by means of surface modification. Polylactide, polyethylene terephthalate glycol, and thermoplastic polyurethane were used as the polymer matrices. The conductive polymer complex poly(3,4-ethylenedioxythiophene) poly(styrene sulfonate) (PEDOT:PSS) was applied as a surface modifier. The modification procedure consisted of impregnating polymer samples with an aqueous PEDOT:PSS dispersion followed by thermal treatment. Electrical properties of the obtained composites were evaluated by measuring resistance and calculating specific electrical conductivity. Surface modification was shown to increase the conductivity of the polymers by 12–14 orders of magnitude compared to the initial dielectric materials. The highest specific conductivity was achieved for the polyethylene terephthalate glycol + PEDOT:PSS composite and reached 9.26×10^-2 S/m. The conductivity of the polylactide-based composite was 2.73×10^-3 S/m, while thermoplastic polyurethane exhibited the lowest value of 3.97×10^-6 S/m, which is attributed to the structural features and reduced wettability of the elastomer surface. Optimal processing parameters were established as 30 minutes of ultrasonic treatment and a drying temperature of 100 ℃. Dispersion dilution with water was found to reduce electrical conductivity, whereas the addition of organic solvents to the modifier was ineffective. A synergistic effect was revealed when combining bulk filling of polylactide with multiwalled carbon nanotubes and subsequent surface modification with PEDOT:PSS, with maximum conductivity observed at a nanotube content of 7 %. The results demonstrate the practical potential of the proposed method for manufacturing electrically conductive functional components using additive manufacturing technologies.

This study addresses the pressing issue of monitoring the ionic composition of aqueous media, which is of significant importance for the energy sector. Particular attention is paid to the development of new ionophores, environmentally friendly plasticizers, miniaturization technologies, and methods for increasing the service life of sensors. In the experimental portion of the study, a laboratory conductivity meter based on a unique cell manufactured using 3D printing was developed and tested. A comparative evaluation of electrodes made of various materials was conducted: copper, graphite and composite polymers with added graphite powder. The results showed that copper electrodes provide high measurement accuracy, while graphite electrodes exhibit overestimated readings at low concentrations due to their surface properties. This study confirms the effectiveness of the proposed approach and forms the basis for further research into the development of optimized electrode materials for ion-selective elecrodes.

Sulfide-alkaline wastewater (SAW) from petrochemical plants, particularly from pyrolysis and hydrotreating units, presents a significant environmental challenge due to its high toxicity, extreme alkalinity (pH > 12), and high concentrations of sulfides and organic pollutants. Traditional treatment methods like acid neutralization or air oxidation are often inefficient, generate secondary waste, or fail to recover valuable components. This study investigates the effectiveness of a novel electrochemical system for the simultaneous treatment of SAW and recovery of valuable products. A lab-scale four-chamber electrodialyzer, equipped with cation-exchange membranes and nickel bipolar electrodes, was designed and tested using real industrial wastewater. The wastewater was characterized by a pH of 13.06, chemical oxygen demand of 12,600 mg/L, and a sulfide content of approximately 5000 mg/L. The process leverages anodic oxidation to convert sulfide ions into elemental sulfur, while sodium cations migrate through cation-exchange membranes to the cathodic compartments. There, water reduction generates high-purity hydrogen (≥99.9%) and a concentrated, purified sodium hydroxide solution. The results demonstrate the ineffectiveness of electrodialysis with anion-exchange membranes due to rapid membrane degradation. In contrast, the proposed electrodialyzer with bipolar electrodes achieved excellent performance: a caustic soda solution with a concentration of 2.3–2.5% was recovered with a current efficiency of 83–85%, containing only trace amounts of sulfides (0.0052%) and organic impurities (0.053%). The process completely removed the original sulfide alkalinity. The study confirms the chemical and mechanical stability of the cation-exchange membranes under harsh SAW conditions. The proposed technology offers a path towards a closed-loop system in refineries by enabling the reuse of recovered caustic, utilization of hydrogen, and potential recovery of sulfur, aligning with the principles of green chemistry and circular economy.

Sulfide-alkaline wastewater (SAW) from petrochemical plants, particularly from pyrolysis and hydrotreating units, presents a significant environmental challenge due to its high toxicity, extreme alkalinity (pH > 12), and high concentrations of sulfides and organic pollutants. Traditional treatment methods like acid neutralization or air oxidation are often inefficient, generate secondary waste, or fail to recover valuable components. This study investigates the effectiveness of a novel electrochemical system for the simultaneous treatment of SAW and recovery of valuable products. A lab-scale four-chamber bipolar electrolyzer, equipped with cation-exchange membranes and nickel electrodes, was designed and tested using real industrial wastewater. The wastewater was characterized by a pH of 13.06, chemical oxygen demand of 12600 mg/l, and a sulfide content of approximately 5000 mg/l. The process leverages anodic oxidation to convert sulfide ions into elemental sulfur, while sodium cations migrate through cation-exchange membranes to the cathodic compartments. There, water reduction generates high-purity hydrogen (≥99.9%) and a concentrated, purified sodium hydroxide solution. The results demonstrate the ineffectiveness of conventional electrodialysis with anion-exchange membranes due to rapid membrane degradation. In contrast, the proposed bipolar membrane electrolysis achieved excellent performance: a caustic soda solution with a concentration of 2.3–2.5% was recovered with a current efficiency of 83–85%, containing only trace amounts of sulfides (0.0052%) and organic impurities (0.053%). The process completely removed the original sulfide alkalinity. The study confirms the chemical and mechanical stability of the cation-exchange membranes under harsh SAW conditions. The proposed technology offers a path towards a closed-loop system in refineries by enabling the reuse of recovered caustic, utilization of hydrogen, and potential recovery of sulfur, aligning with the principles of green chemistry and circular economy.

The paper presents the results of a comprehensive study of the functional properties of electrically conductive composites obtained by surface modification of polymer materials for 3D printing – polylactide (PLA), polyethylene terephthalate glycol (PETG), and thermoplastic polyurethane (TPU) – with a conducting polymer complex of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). The piezoresistive response of the samples was studied under mechanical bending deformation in the range of 0–2%. The gauge factor (GF) was calculated. The PETG + PEDOT:PSS composite demonstrated the highest sensitivity with a maximum GF of ≈ 47, which is due to the formation of a rigid and well-adhered conductive layer that is prone to cracking during deformation. For the PLA + PEDOT:PSS and TPU + PEDOT:PSS composites, the maximum GF values were ≈ 19.5 and ≈ 13.5, respectively. A study of the Joule heating effect under a constant voltage of 70 V revealed a slight increase in the sample temperature (ΔT = 0.5–1.9 °C), which is due to the high resistivity of the surface layer. It was shown that, despite their limited effectiveness for active heating purposes, the materials exhibit stability when subjected to current flow. These findings demonstrate the potential of these composites for the development of passive strain sensors and flexible electronic components using additive manufacturing techniques in nuclear power plants (NPPs).