Narrow Results

To enhance the power-to-hydrogen (P2H) efficiency and multiple energy utilization efficiency of the hydrogen-electric integrated energy system (HE-IES), an optimal operation framework considering the P2H factor is proposed. First, the proton exchange membrane electrolytic cells model which considers mass transfer characteristics is established. Efficient hydrogen production operating parameters are obtained through simulation to maximize the P2H efficiency. Second, the HE-IES is established, including the hydrogen flow system, wind power (WP), energy storage systems, gas boiler, combined heat and power and methanation unit. Based on the characteristics of the devices and efficient hydrogen operating parameters, the optimal operation framework considering the P2H efficiency factor is proposed. To realize the low economic operating costs and maximize the utilization of WP, a multi-objective function based on fuzzy membership function solving is applied. Finally, the case studies show that the proposed operation framework reduces the economic operation cost by 28.29% and improves the WP utilization rate by 31.9%.

Advanced technological achievements and the continuous growth of economy have made the disposal, recycle and reuse of industrial by-products a severe challenge. The cement industry is considered one of the key sectors in this effort in successfully (in terms of not extenuating but improving some of the properties of the final product) absorbing large quantities of solid wastes, either as aggregates or as secondary cementitious materials. This not only contributes to the creation of an energy and CO₂-emission depository (as commonly used raw materials are spared), but also simultaneously alleviates the acute environmental burden caused by the irresponsible disposal of such by-products. In this study, the possibility of reusing spent fluid catalytic-cracking catalyst (FCC) as a supplementary cementing material (SCM) was examined. A series of tests were conducted, initially aiming at characterizing the material and thereafter evaluating its pozzolanic activity and its effect on the mechanical properties of blended cements. Major findings in this investigation revealed that the use of FCC as a mineral admixture in cement is feasible, strengthening the belief that si-liceous glassy residues should represent a steady supply for the construction sector.