Regional renewable energy and resource planning

The exploitation of the energy potential in biomass in a specific geographical region is frequently constrained by high production costs and the amount of land required per unit of energy generated. In addition, the distributed nature of the biomass resource and its normally low energy density may result in large transportation costs. Biomass also requires large land areas to collect and process the incoming solar radiation before the energy can be harvested. Previously published works on regional energy clustering (REC) and the Regional Resources Management Composite Curve, RRMCC (in this paper shortened to RMC), have been extended in this paper to tackle simultaneously the issues of the biomass supply chain, transportation, and land use. The RMC is a tool for supporting decision making in regional resource management. It provides a complete view of energy and land availability in a region, displaying their trade-offs in a single plot. The extension presented in this work has been developed in two steps. The first step presents the Regional Energy Cascade Analysis, which estimates the energy target within regional supply chains and provides the result for energy exchange flows between zones, the quantity of energy required to be imported/exported, and the locations of the demands. In the second step, the initial results are analysed against potential measures for improving the energy and land use targets by using the RMC and a set of rules for its manipulation. The presented method provides the option to assess the priorities: either to produce and sell the surplus energy on the fuel market or use the land for other purposes such as food production. This extended approach is illustrated with a comprehensive case study demonstrating that with the RMC application it is possible to maximise the land use and to maximise the biofuel production for the requested energy demand.     

Strategies to enhance dry reforming of methane: Synthesis of ceria-zirconia/nickel–cobalt catalysts by freeze-drying and NO calcination

To improve the activity of nickel–cobalt (NiCo) catalyst supported on ceria-zirconia (CeZr) in the dry reforming of methane (DRM) with carbon dioxide, and to lower the coking rate in this process, 1.5 wt.% and 2.5 wt.% NiCo catalysts were prepared using two approaches, i.e. freeze-drying (FD) and NO calcination for comparison against oven-drying (OD) and air calcination (air), respectively. Their impact was studied for 20 h of DRM at 750 ^°C and 1.2 bar, with undiluted CH₄–CO₂ feed simulating the real conditions. NO-calcined samples show, on average, more pronounced improvement through increased conversion of CH₄ (90%), followed by FD samples (85%) from the air and OD-prepared samples (both 82%). Coking content varied between 0.67 and 0.82 wt.%. The observed slow catalyst deactivation might be caused by sintering of the catalysts. Higher quantity of CO than H₂ for syngas production was obtained, owing to concurrent reverse water-gas shift side reaction, and high redox properties of the defective CeZr lattice that enabled surface carbon gasification by continuous replenishment of oxygen from the support to produce CO, of which the latter phenomenon also explains the low carbon deposition. H₂/CO ratio between 0.42 and 0.85 was achieved, with FD and NO samples fared better (0.83–0.85) over the ones prepared by conventional methods (0.73–0.82) for 2.5%NiCo loaded catalysts.     

Economic Policy Uncertainty Index Meets Ensemble Learning

Computational Economics - We utilize a battery of ensemble learning techniques [ensemble linear regression (LM), random forest], as well as two gradient boosting techniques [Gradient Boosting...     

The intertwining issues of energy security,environmental protection,and societal development

Clean Technologies and Environmental Policy -     

The viscosity effect on autoacceleration of the rate of free radical polymerization

The reaction kinetics at 70°C were investigated for the suspension polymerization of methyl methacrylate initiated by benzoyl peroxide in the presence of variable amounts of dodecyl mercaptan. A dilatometric method designed to follow a suspension polymerization was used. It showed that the autoacceleration of the rate of polymerization begins at higher conversions and becomes less pronounced as the concentration of chain transfer agent is increased. The investigations focused on the determination of the viscosities of the reaction mixtures at the onset of autoacceleration. It was concluded from the flow curves obtained for different reaction mixtures that there exists a critical solution viscosity at which the autoacceleration begins, which supports the accepted theory about the nature of this phenomenon. Measured at a shear rate of 10,000 s^?1 and at 25°C this viscosity was found to equal 0.6 poise regardless of the molecular weight of the growing polymer.