刊·见 | 能源领域SCI期刊，呵护地球绿色肌肤

The aim of this study was to investigate a new approach for reducing the production of harmful Cr(VI) heavy metals in the collaborative disposal of Red mud by cement enterprises. The study examined the effects of different ratios on the conversion rate of Cr(VI) in clinker under various calcination temperatures and atmospheres, and analyzed the raw material composition, clinker composition, and Cr(VI) content using XRD and XPS. The results indicate that the conversion rate of Cr(VI) is positively correlated with the concentration of oxygen, with the highest conversion rate of 93.4% achieved at 15% oxygen concentration. XPS analysis revealed that the peak intensity of Cr(VI) in clinker calcined under 4% O2 atmosphere was significantly higher than that of the sample calcined under 4000 mg/kg CO atmosphere. The study also found that the concentration of CO can reduce the conversion rate of Cr(VI) at high calcination temperatures, while at low calcination temperatures, the change in CO concentration has little effect on the conversion rate of Cr(VI). The specific objectives include examining the effects of different ratios, calcination temperatures, and atmospheres on the conversion rate of Cr(VI) in clinker. Additionally, when the ratio is the same as the calcination atmosphere, increasing the calcination temperature leads to an increase in the conversion rate of Cr(VI). The obtained results suggest a new approach for reducing the production of Cr(VI) in the collaborative disposal of Red mud by cement enterprises, which could have practical applications in engineering environmental protection.

4E (energy, exergy, exergoeconomic, and environmental) analyses of a reformed methanol high-temperature proton exchange membrane fuel cell (RM HT-PEMFC) system identify inefficiencies, assess associated costs, and evaluate environmental impacts. However, such studies remain limited in the literature, particularly those exploring the impact of the operating parameters of the methanol steam reforming in the combined RM HT-PEMFC and single-effect absorption refrigeration cycle (ARC). This study addresses this gap by analyzing a tri-generation consisting of the RM HT-PEMFC and the single-effect ARC. Simulation results indicate a total exergy destruction of 21.65 kW, a total cost rate of 8.93 $/h, an exergoeconomic factor of 43.22%, and an exergy efficiency of 33.06% in the baseline case. Notably, the stack and burner account for the highest irreversibility, contributing 67.75% of total exergy destruction and 55.71% of the total cost rate. Parametric studies on four key variables – current density, stack temperature, reformer temperature, and steam-to-carbon ratio – reveal that higher system exergy efficiency is generally associated with lower carbon dioxide emissions. Uncertainty analysis shows that extending the HT-PEMFC’s lifespan to 40,000 h can reduce exergy cost per unit product by 16.23%, while decreasing the price of green methanol to 11.00 $/h can lower costs by 26.97%.