• Energy Research

The potential of micro-hydropower generation has been evaluated in seven community-owned rural water supply networks (CORWSN) in Ireland. The replacement of the existing infrastructure in place to reduce pressure in the networks with micro-hydropower turbines (Scenario 1) was considered. New potential locations for additional pressure reduction were also considered (Scenario 2). An assessment of the energy potential and economic viability of each site was carried out, including quantification of leakage reduction impacts. While only one of the seven CORWSNs showed two potential sites with power higher than 1 kW, the power generated can still have significant impacts on local energy demands. The estimated total energy saved in Scenario 2 ranged from 0.63 MWh year−1 to 84.5 MWh year−1 according to the micro-hydropower potential in each CORWSN. Furthermore, water savings from 4348 € m−3 to 73,264 € m−3 were estimated due to the reduction of leakage volume after installing micro-hydropower turbines at the potential sites detected in Scenario 2. Thus, the water cost saving associated to the reduction of leakage volume makes the incorporation of this element in the networks feasible.

According to existing literature, there are no conclusive results on the impact of stirring on hydrothermal carbonization (HTC); some studies report a significant impact on the product's properties, while others indicate no influence. This study investigates the influence of stirring rate on several responses and properties of HTC products, including solid mass yield, solid carbon fraction, surface area, surface functional groups, morphology, and the fate of inorganic elements during HTC. Waste biomass was introduced as a feedstock to a 2 L HTC reactor, where the effects of temperature (180-250 °C), residence time (4-12 h), biomass to water (B/W) ratio (1-10%), and stirring rate (0-130 rpm) were investigated. The findings of this study conclusively indicated that the stirring rate does not influence any of the studied responses or properties of hydrochar under the selected experimental conditions used in this study. Nevertheless, the results indicated that a low-stirring rate (5 RPM) is enough to slightly enhanced the heating-up phase of the HTC reactor. For future research, it is recommended to examine the impact of stirring rate on the HTC of other types of biomass using the methodology developed in this study.

AbstractWater distribution networks have a significant water and energy demand and, therefore, must face the challenge of adopting measures that improve how these resources are used. Previous inves...