Cement production is one of the key industries responsible for emissions of greenhouse gases, especially carbon dioxide (CO2), which influence climate change. In order to reach zero carbon in the cement industry, various deep decarbonization pathways involving carbon capture, storage, and utilization (CCSU), using low-carbon material and fuel, optimal process control, and waste heat utilization techniques must be implemented. As for the example of Uzbekistan, approximately 30 facilities generate more than 15 Mt of cement annually and are responsible for 11.3% of the country's total CO2 emissions. In this study, decarbonization pathways for cement plants in Uzbekistan, including CCSU, the use of alternative fuels, electrification, and waste heat integration techniques, are compared based on existing challenges and opportunities. The availability of alternative fuel and material resources suitable for the total production capacity, the comparison of post-combustion, pre-combustion, and oxyfuel combustion CCSU methods for the cement plant, and the use of energy-efficient technologies are discussed.
Digestate (anaerobic ferment) is an organic substance remaining after the anaerobic processing of organic matter or biodegradable waste—biogas extraction or anaerobic alcoholic fermentation— or bioethanol extraction. Biogas production waste digestate is a valuable fertilizer in agriculture, but there are issues with odor emissions. Therefore, in order to reduce environmental air pollution, the efficiency of integrating a homogenized biosolution—an activator of rotting residues into the digestate for ammonia emission—was evaluated via scientific studies of ammonia gas emission. The purpose of the study is to evaluate the effect of a homogenized biosolution—the rotting residue activator (carrier molasses without GMO) in the digestate—on reducing ammonia emissions. The assessment of ammonia gas emission was performed by measuring the average ammonia concentration values fixed in time intervals every 15 min via the automatic switching of the analyzer channels, in order to first assess the sudden immediate effect of the biosolution and the regular gradual long-term effect. After evaluating the average concentration and emission of ammonia gas from the control and digestate with biosolutions depending on the duration of digestate storage, the correlation of the values compared with each other was established and the effect of the allocation of the biosolution—the rotting residue activator in the digestate—on the reduction of ammonia concentration and emission was recorded. The highest efficiency of the biosolution in reducing ammonia emissions ranged from 3 to 43% in the period from 1 to 100 h, which reached up to 450,000 mg m−2h−1. After evaluating the overall average reduction in ammonia emissions from the digestate with the biosolution over the entire period, the essential effect of the use of biosolutions was proven and the highest effect was recorded in the first 24 h after the allocation of the biosolution—the activator of rotting residues in the digestate. Thus, supplementing the digestate with various nutrients and specialized biosolutions provides an even better fertilizing value and even better prospects for reducing odor emissions.
This work presents a novel, highly sensitive, and directional piezoelectric cantilever-based micro-electro-mechanical system (MEMS) device conceived using a biomimetic approach of a fish’s lateral line system for marine sensing robotics. The device will consist of twelve cantilevers with different lengths in a cross-shaped configuration made with a piezoelectric thin film (PZT, ZnO, BaTiO3) embedded between the top and bottom metals, Platinum (Pt) and Aluminum (Al), used as electrodes. This unique design of cantilevers in circular shapes has the advantage of directional response. A comparative study of these piezoelectric materials was performed analytically through the finite element method to design, model, and simulate our device in COMSOL software. Cantilever microstructures were simulated with lengths ranging from 100 to 1000 mm. The results show that PZT has the best performance with these materials. The maximum potential voltage was shown as 1.9 mV using the PZT material cantilever with 29 µm displacement.
Biochar (BC) has been a viable resource in producing functionalised carbonaceous materials beneficial in soil fertility, environmental remediation, and energy recovery. In this study, the influence of Na2CO3 on the pyrolytic conversion of green pea peels to BC was examined to assess BC’s yield and physicochemical characteristics. Experiments were conducted in batch processes at a constant temperature of 500 °C by wet impregnation using 0%, 10%, 20%, and 30% (w/w) ratios of Na2CO3 catalyst to biomass weight. Characterisations of the produced BC materials were conducted by bomb calorimetry, SEM, BET, FTIR, and XRD. Accordingly, catalyst incorporation by pretreatment resulted in a decrease in yield while increasing the porous development. The specific surface area at a constant temperature increased from 1.006 to 17.7 m2 g−1, and the pore diameter decreased from 173.1 to 9.283 nm. The oxygenated functional groups negatively correlated with the increase in the amount of catalyst, whereas the calorific values of the synthesised materials increased from 20.313 kJ g−1 to 25.479 k Jg−1 when the catalyst impregnation ratio was enhanced from 0% to 30%, indicating that BC produced from catalysed processes demonstrates better energy recovery potential.
