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Effective municipal solid waste (MSW) management and waste-to-resource recovery has a key potential to play a vital role in economic growth of a country. MSW contains the different items of daily use that makes its composition mix in nature. Different waste-to-energy techniques are already available to treat this waste but these techniques always require some pretreatments such pre-separation and pre-drying of mix MSW that makes these processes less techno-economic to apply on large scales. To provide an effective solution to this problem, potential wet oxidation technique has been reviewed in this study. In the first section, the statistics for MSW generation and composition for different cities in Poland have been presented to show the existence of maximum organic content which can be converted to useful organic compounds. In the later section, the wet oxidation technique and its various aspects have been reviewed in detail to justify the potential of this technique to treat mix MSW at larger scales to produce different valuable products in the context of waste-to-resource recovery. [ABSTRACT FROM AUTHOR]

Various waste streams including municipal solid waste (MSW), polymer waste from personal protective equipment (PPE) used in medical fields, and composite waste from wind turbine blades (WTBs) demand modern waste management and recycling approaches. Ultimate and proximate analysis of mentioned samples revealed a higher content of carbon—28.2 ± 8.0, 80.1 ± 2.3, and 50.3 ± 2.3, respectively—exhibiting sufficient potential to be converted into secondary carbon-based compounds. For this purpose, oxidative liquefaction of selected waste materials was carried out following a detailed experimental plan, a centred composite design for WTBs, and a central composite face-centred plan for MSW and PPEs. Temperature, pressure, oxidant concentration, reaction time, and waste-to-liquid ratio were the parameters of key interest, and their values were tested at a range of 200–350 °C, 20–40 bar, 15–60%, 30–90 min, and 3–25%, respectively, depending upon the type of waste. As a result, total polymer degradation (TPD) was recorded for three types of waste and the results were satisfactory, encouraging the decomposition of primary waste in liquid oxygenated chemical compounds (OCCs). Gas Chromatography with Flame Ionisation Detection (GC-FID) helped us quantify the number of OCCs for each waste sample. Energy consumption during the process was also recorded and optimisation of the experimental plan based on maximum TPD and OCCs yields against the minimum energy consumption was performed to make the process tech-economic. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) of composite materials is promising to create customizable products with enhanced properties, utilizing materials like carbon fibers (CFs). To increase their circularity, composite recycling has been proposed to re-introduce the recovered components in AM. A careful evaluation of recycling is necessary, considering the sustainability and functionality (i.e., mechanical properties) of the recovered components. Thus, Life Cycle Assessment (LCA) is applied to estimate the environmental impacts of AM via Fused Filament Fabrication (FFF), using virgin or recycled CFs via solvolysis at a laboratory scale. This study aims to provide a detailed Life Cycle Inventory (LCI) of FFF and evaluate the sustainability of using recycled CFs in AM. For both virgin CF manufacturing and CF recycling, electricity consumption was the main contributor to environmental impacts. CF recovery via solvolysis resulted in lower impacts across most impact categories compared to AM with virgin CFs. Different scenarios were examined to account for the mechanical properties of recycled CFs. AM with 75% recycled CFs, compared to 100% virgin CFs undergoing landfilling, resulted in over 22% reduction in climate change potential, even after a 50% loss of recycled CF functionality. Overall, this study offers insights into the LCI of FFF and shows that CF recycling from composites is worth pursuing. [ABSTRACT FROM AUTHOR]

This work aims to assess the effect of the operating parameters of the gasifying agent preheating temperature and equivalence ratio (ER) on the conversion of sewage sludge (SS) to syngas through gasification and combined heat and power (CHP) generation. A novel gasification model was simulated in Aspen Plus to represent a fixed-bed updraft gasifier to generate syngas from SS through an equilibrium approach restricted by temperature. The novelty of this work is that the model was developed by applying the gasifying agent preheating temperature as an operating variable instead of the gasification temperature. It was calibrated by using a set of experimental values and then validated by comparing the numerical results with the experimental outcomes related to nine different operating conditions of air preheating temperatures and ER. A good agreement between the simulation and experimental results was observed. The optimum gasification process parameters of the air preheating temperature and ER were predicted to be 150 °C and 0.2, respectively. The CHP generation potentiality of SS was assessed to be 2.54 kW/kg SS as dry solids (DS), of which 0.81 kW was electrical and the remainder was thermal power. The conversion of SS to CHP through the proposed treatment can reduce 0.59 kg CO₂/kg SS as DS emissions compared with that of natural gas combustion to generate a similar quantity of energy. [ABSTRACT FROM AUTHOR]

Paper present the experimental and numerical analysis of biomass photopyrolysis process. The experimental tests is performed on the solar pyrolysis installation, designed in Institute of Thermal Technology, Gliwice. It consist of the copper reactor powered by artificial light simulating sun. The paper shows the result of the solar pyrolysis of wood. The yield of the main fraction as a function of the process temperature is presented. Additionally the gas composition is determined. The numerical model is prepared in the Ansys Fluent 18.2 software, which allow at the same time for capturing geometry of the real system and easy change of input data. The results indicate that both the product yields (liquid, solid and gaseous) and gas components shares are strongly influenced by pyrolysis parameters and feedstock composition.

In this investigation, ignition processes of the methane and the propane using a high-temperature oxidizer (Toxi > Tai) with a varying oxygen concentration zO2 - the HTAC (High Temperature Air Combustion) conditions, applying a constant-volume bomb (CVB) was investigated. The influence of the initial temperature of the oxidizer Toxi was analyzed and discussed. It is shown that in order to achieve an effective reaction of ignition the oxidizer temperature needn't be maximized. Detailed evolution of ignition delay time with equivalence ratio τig was presented. It can be concluded that increment of oxygen concentration zO2 in oxidizer results in decrease of τig. Trials with propane are characterizing lower values of ignition delay time τig in comparison with methane.

Effective use of utilities in production plants is an issue that is becoming increasingly significant in energy policy of Europe. Production of compressed air consumes 3% of the total electricity consumption in Europe. In order to produce compressed air, approximately 10-20% of electricity transferred to compressor is used, the rest is lost due to lack of tightness and heat losses. The aim of this work is to evaluate the possibility to install recovery systems on air compressors to recover the lost waste heat and its management for the needs of heating office buildings/production halls and analysis of investment profitability. The investment will be supported by co-financing in the form of energy efficiency certificates (so-called white certificates), which the production plant will be able to sell after receiving them from Polish Energy Regulatory Office in return for completing an investment that consists recovering waste heat from air compressors.