Utilization of energy crops and sewage sludge in the process of co-gasification for sustainable hydrogen production

The increasing world energy demand driven by economic growth and technical development contributes to the severe depletion of conventional energy resources and various environmental issues. The need for the employment of low-emission, highly efficient technologies of thermochemical conversion, flexible in terms of both raw resources and product applications is declared, when the utilization of solid, alternative fuels is considered. Gasification is the proven technology of lower unit emission of contaminants and higher efficiency than combustion systems, as well as versatile applicability of the synthesis gas, as its main product. While the conversion of fossil fuels in gasification systems is technically mature, the co-utilization of biomass and waste still requires research and optimization in various technical and economic aspects. In this paper, the results of experimental work on co-gasification of energy crops biomass and sewage sludge with steam to produce hydrogen-rich gas are presented. The process is performed at 700, 800 and 900°C under atmospheric pressure. The experimental results are analyzed with the application of the Hierarchical Clustering Analysis. The optimal results in terms of hydrogen production in co-gasification of selected biomass and sewage sludge are observed for Helianthus tuberosus L. blends of 10% w/w of sewage sludge content at 900°C

Changes in the Distribution of Temperature in a Coal Deposit and the Composition of Gases Emitted during Its Heating and Cooling

This article presents the results of tests conducted on a measuring system for monitoring changes in the distribution of temperature in a coal deposit during the heating and cooling phases, and their correlation with the analysis of the concentration of gases. The tests were conducted on five samples of hard coal collected in deposits mined in Poland. Measurements of the changes in temperature and changes in gas concentration were conducted from the temperature of 35 to 300 C, for the heating phase, and from 300 to 35 C, for the cooling phase. The percentage share of coal of given temperatures was calculated. When comparing the percentage share for the same temperature in the hot spot, for the heating and cooling phase, significant differences in the distribution of the given percentages were observed. Changes in gas concentrations during heating and cooling were analyzed and the dynamics of changes in gas concentrations were determined for the coals tested. Changes in the values of fire hazard indices were analyzed. There were significant differences in the concentration of gases and the values of fire hazard indices between the heating and the coolin

Electrochemical corrosion monitoring in low conductive fluid : pilot-scale study on sulfolane corrosion potential

Solvents are a group of chemical compounds that are widely used in organic synthesis. Taking into account the chemical nature, solvents are divided into protic and aprotic ones. An attractive alternative to commonly used industrial extractive liquids is an anthropogenic, organosulfur medium—sulfolane. Sulfolane is a five-membered heterocyclic sulfur–organic compound from the group of sulfones (R-SO2-R’, where R/R’ is alkyl, alkenyl, or aryl), which contains an apolar hydrocarbon backbone and a polar functional group. It is a selective solvent in the liquid–liquid and liquid–vapor extraction processes used for the removal of close-boiling alkanes from cycloalkanes or for the separation of compounds with different degrees of saturation and polarity in the extractive rectification of arenes from non-aromatic saturated hydrocarbon mixtures. In standard conditions sulfolane is not an aggressive solvent for steel, but at higher temperature (170–180 °C) and oxygen availability, it may be decomposed and subsequently some corrosive (by-)products can be formed. The primary purpose of the presented pilot-case examination was to verify applicability of the industrial, multi-electrochemical technique for reliable detection of the corrosion processes in low conductive fluids

Hydrogen rich gas production through co-gasification of low rank coal, flotation concentrates and municipal refuse derived fuel

In the paper a novel approach to thermochemical utilization of low rank coal, flotation concentrates and municipal refuse derived fuels was presented. The economic attractiveness of low rank coals and flotation concentrates is limited and that is why they are commonly stored at excavation heaps causing additional costs and the risk of endogenous fires occurrence. One of the crucial parameters determining the attractiveness and usability of a fuel in the gasification process is its reactivity. In the study several low rank coals, flotation concentrates and municipal refuse derived fuels were tested in terms of their reactivity in the process of steam gasification. The reactivity of low rank coal and flotation concentrates at 50% of carbon conversion, R50, varied between 1.46$10 4 and 2.39$10 4 s 1, whereas the maximum reactivity, Rmax, from 3.28$10 4 to 4.62$10 4 s 1. Advanced mathematical models were developed to investigate the similarities and dissimilarities between the studied fuels as well as the relationships between the physical and chemical parameters and the reactivities of fuel chars in steam gasification. On this basis, a low rank coal was selected and blended with 20%w/w of municipal refuse derived fuel in cogasification experiments. The aim of the research was to utilize the low rank coal characterized by the lowest reactivities (R50 and Rmax of 1.46$10 4 and 3.28$10 4 s 1, respectively) in steam co-gasification to hydrogen-rich gas with an alternative fuel in a fixed bed reactor at the temperature of 800 C. The selected low rank coal was blended with 20%w/w of municipal refuse derived and the resulting fuel yielded the average concentration of hydrogen in the produced gas of 58.99%vol

CFD numerical modelling of a PV–TEG hybrid system cooled by air heat sink coupled with a single-phase inverter

This study presents full transient, three-dimensional numerical models of a PV–TEG hybrid module coupled with single-phase inverter by co-simulation. The influence of factors, such as wind speed, solar radiation intensity, or ambient temperature on the PV–TEG system, was also examined. The numerical model was implemented using Ansys software which accounted the phenomena of Thomson, Seebeck, and Joule’s heat place on the TEG system. Furthermore, its impact on total electrical efficiency was studied. The heat transfer surface of the passive heat sink and forced air circulation positively affected the total heat transfer, and therefore helped to maintain the electrical efficiency at a higher level. Simulation of the single-phase inverter with a PV–TEG system allows the determination of the power characteristics of the system in real time. The results of the study presented may provide a basis for performance optimization of a practical PV–TEG-inverter hybrid system co-design

Real-time corrosion monitoring of AISI 1010 carbon steel with metal surface mapping in sulfolane

Solvents are widely used in organic synthesis. Sulfolane is a five-membered heterocyclic organosulfur sulfone (R-SO2-R’, where R/R’ is alkyl, alkenyl, or aryl) and an anthropogenic medium commonly used as industrial extractive solvent in the liquid-liquid and liquid-vapor extraction processes. Under standard conditions sulfolane is not aggressive towards steel, but at higher temperatures and in oxygen, water, or chlorides presence, it can be decomposed into some corrosive (by-)products with generation of SO2 and subsequent formation of corrosive H2SO3. This pilot-case study provides data from laboratory measurements performed in low conductivity sulfolane-based fluids using an industrial multi-electrochemical technique for reliable detection of corrosion processes. In particular, a comprehensive evaluation of the aqueous phase impact on general and localized corrosion of AISI 1010 carbon steel in sulfolane is presented. Assessment of corrosive damage was carried out using an open circuit potential method, potentiodynamic polarization curves, SEM/EDS and scanning Kelvin probe technique. It was found that an increase in the water content (1–3 vol.%) in sulfolane causes a decrease in the corrosion resistance of AISI 1010 carbon steel on both uniform and pitting corrosion due to higher conductance of the sulfolane-based fluids

Electrochemical corrosion monitoring in low conductive fluid : pilot-scale study on sulfolane corrosion potential

Solvents are a group of chemical compounds that are widespread in the organic chemistry. Taking into account the chemical nature, solvents are divided into the protic and aprotic ones. An attractive alternative to commonly used indus-trial extractive liquids is an anthropogenic, organosulfur medium – sulfolane. Sulfolane is a five-membered heterocyclic sulfur-organic compound from the group of sulfones (ArSO2), which contains an apolar hydrocarbon backbone and a polar functional group. It is a selective solvent in the liquid-liquid and liquid-vapour extraction processes used for the removal of close-boiling alkanes from cycloalkanes or for the separation of compounds with different degree of satu-ration and polarity in the extractive rectification of arenes from non-aromatic saturated hydrocarbon mixtures. In the standard conditions sulfolane is not an aggressive solvent for steel, but at higher temperature (170-180ºC) and oxygen availability, it may be decomposed and subsequently some corrosive (by-)prod-ucts can be formed. The primary purpose of the presented pilot-case study was to verify the applicability of the industrial, multi-electrochemical technique for reliable detection of the corrosion processes in the low conductive fluids

A Generalized view of longwall emergency stop prevention (Ukraine)

Based on both theoretical and practical experiences, the measures aimed at controlling emergency shutdowns of stopes have been highlighted. These stopes are connected with the emergency rigid settlements of powered complexes. In terms of the Western Donbas mines, there are certain risks of a shutdown of stopping operations within the zone of primary roof caving. Thus, the causes of emergency rigid settlements of the support may include the following: layers of the main roof rocks are hanging and not timely delaminated; sudden changes in lithology; hydraulic overloading of the main roof; structural flaws of support under certain conditions of its use, etc. In this paper, the theoretical method of scientific cognition was applied, which, with its help, makes it possible to switch from single low-efficiency measures to a set of actions aimed at preventing any uncontrolled situation. Obtaining certain generalized knowledge means obtaining a much deeper representation of reality, penetrating into its essence. The study also involves statistical analysis, being the basis for outlining a zone of primary caving where a high degree of risk is observed. Certainly, the generalization of these measures does not solve the problem completely. Consequently, there will be further attempts to search for and achieve principal new solutions in the future

Mine Field Preparation and Coal Mining in Western Donbas: Energy Security of Ukraine—A Case Study

Recent world trends have shown that a country’s political security depends on its fuel and energy supply. In Ukraine, these issues are managed by the United Energy System of Ukraine (USE). The USE consists of a set of power plants as well as electric and thermal networks operating in the general mode of production, transmission and distribution of electric and thermal energy. Nuclear power plants (NPPs), thermal power plants (TPPs), hydroelectric power plants (HPPs), thermal power plants (CHPs), as well as power plants run on alternative (renewable) sources of electricity (solar, wind, bio- and others). They are operating in one system. All of them are connected by the main electric networks. Thermal power plants (TPPs) produce nearly 27% of all electrical energy in Ukraine [1]. Recently, the amount of commercial coal required by Ukraine’s energy sector has increased from 19 to 21 million tons. In 2021, coal production had decreased by approximately 7.7% compared to 2020. Accordingly, this requires the import of coal [1]. Therefore, increasing the efficiency of coal mining is an urgent scientific and practical task.Ukrainian electricity production sector is in a critical situation. It is necessary to increase the coal production to ensure the continuity of electricity production. In this paper, an analysis of coal mining in western Donbas, Ukraine, was presented. The crucial thing is to increase coal production in this region. The new calculation schemes were proposed to increase coal extraction in Donbas mines. The coal pillar parameters, which are necessary for the effective control of the rock pressure caused by the stooping, were substantiated. The obtained parameters for the coal pillars will allow extracting more coal, safely and quickly dismantling the mechanized complex and effectively protecting the ongoing mine work. The case study helps determine the coal losses because of pillar leaving and to improve the stability of the main haulage roads located in the zone of the stooping effect as well as to achieve additional coal production in the mine. Such a technological solution allows to extract the coal more fully at the final parts of the extractive columns and to obtain an additional economic effect. The increase in coal production in coal mines of western Donbas will increase the energy security of all Ukraine