The study assessed changes in energy, temporal, technological, environmental, and washing-quality parameters after introducing a central heat recovery system in an industrial laundry. Instrumental measurements, gravimetric and microbiological methods, textile mechanical testing, and calculations of energy-efficiency and carbon dioxide (CO2)-emission indicators were applied. Specific heat energy consumption decreased from 7.8 to 4.6 kWh/kg, while heat energy use for 100 t of laundry fell from 780 to 460 MWh. Recovered heat supplied 42% of the total heat demand, reducing steam-boiler load from 100% to 72% and shortening the washing cycle from 35 to 30 min. Washing-tunnel performance increased from 1000 to 1200 kg/h, and completed cycles per shift increased from 13 to 16. Annual natural gas consumption decreased from 430 to 300 thousand m³, and specific carbon dioxide emissions from 62 to 42 kg/t. Average moisture after drying declined from 6.5% to 4.8%, while laundry ready for folding increased from 78% to 92%. Protein- and fat-contaminant removal and whiteness also improved. A separate ozonation test increased microbial reduction but was not attributed to heat recovery. The integral energy efficiency index increased from 1.00 to 2.03.
In this study, optimum insulation thicknesses were determined for the external walls of buildings in different climatic regions of Turkiye. Energy, economic and environmental performance analyses were carried out by applying optimum insulation thickness for extruded polystyrene () and glass wool as insulating material. According to the thermal insulation rules ( 825) in buildings, for Diyarbak & imath;r, Konya and Kars provinces located in second-, third- and fourth-degree day zones, optimum insulation thicknesses and related energy, economic and environmental performance analyses were made. Life cycle assessment () method was used to determine environmental performance. The optimum insulation thicknesses vary between 0.043 and 0.12 m. Compared to XPS, optimum insulation thickness is higher, both payback period and payback period (LCA) are shorter, and both ES and avoided environmental impact () amounts are higher when glass wool is used for the investigated three provinces. The results indicated that ES and amounts are considerably augmented and LCA is reduced when coal is used compared to natural gas for both insulating materials. According to obtained results, it is suggested that coal as the fuel type and glass wool as the insulation material can be utilised for buildings in the studied three provinces.
Environmental taxes push countries away from carbon-intensive energy, while renewable energy pulls them closer to green energy options. This synergy can be important for environmental quality but little is known about their joint impact on ecological footprint. This study explored moderation and mediation effects in analysing the joint impact of environmental taxes and renewable energy consumption on ecological footprint in Africa, focusing on Ghana, Nigeria, and South Africa from 2017 to 2024. It also examined how renewable energy consumption responds to environmental taxes. The Driscoll and Kraay with Fixed Effects and the Panel-Corrected Standard Error estimators were employed for the analyses. While environmental taxes were found to directly reduce renewable energy consumption, environmental taxes and renewable energy consumption worked together to enhance environmental quality by lowering the ecological footprint based on the moderation and mediation analyses. This suggests a complementary role rather than purely stimulative role of taxation in environmental protection policy and demands a coordinated policy design where environmental tax revenue is invested to promote renewable energy consumption and environmental quality.
Conventional solar stills are constrained by low productivity and limited thermodynamic efficiency. This study experimentally investigates a passive parabolic trough-assisted tubular solar still (TSS-PTC) and compares its performance with a conventional tubular solar still () under identical climatic conditions. A passive parabolic trough reflector is integrated to enhance solar concentration without external energy input, achieving an effective concentration ratio of 2.33 and improving solar energy absorption. Experiments conducted over five consecutive days under peak and average solar irradiance of 970 and 641.5 W/m(2) indicate improved thermal behaviour. The TSS-PTC showed increases in basin water and cover temperatures of 3.84 degrees C and 1.9 degrees C, respectively, leading to a 23.10% rise in the evaporative heat transfer coefficient. Consequently, freshwater productivity increased, with a 54% rise in peak hourly yield and an average productivity improvement of 91.3% compared to the conventional system. The maximum thermal efficiency reached 45.2%, while the conventional one still produced 26.1%. In addition, thermal and exergy efficiencies increased by 59.43% and 91.30%, respectively. Overall, daily distillate output from the TSS-PTC was more than twice that of the conventional still, indicating its suitability for efficient, decentralised solar desalination applications.
Solar drying is increasingly being adopted as a sustainable alternative to conventional fuel-based preservation systems. This study investigates the effect of evacuated tube collector (ETC) count and sand particle size on the performance of a solar dryer integrated with sand-based thermal storage. Experiments were carried out using fine-grained sand (FGS), medium-grained sand (MGS), and coarse-grained sand (CGS) across one-, two-, and three-ETC configurations. Performance evaluation was based on drying rate (g/min) and drying efficiency (%). The results show that drying rate improved consistently with an increase in ETC count, peaking at 0.77 g/min with FGS under three ETCs, followed by MGS (0.63 g/min) and CGS (0.58 g/min) in the same configuration. Fine sand exhibited superior thermal conduction, leading to faster moisture removal, while medium and coarse sands demonstrated steadier drying patterns during late hours. Drying efficiency displayed an opposite trend: the FGS-1 ETC setup achieved the highest efficiency of 70.7%, whereas efficiency declined to 33.4% for two ETCs and 15.8% for three ETCs, regardless of sand size. This analysis highlights the trade-off between maximising drying rate and maintaining energy efficiency.
