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Biomass combined heat and power (CHP) generation is the more efficient use of biomass compared the direct combustion power generation. The techno-economic analysis of 30 MW biomass direct combustion power set’s modification for heat supply is investigated in this work. Three schemes are employed to provide the district heating supply, including low vacuum condenser, steam extraction, and turbine bypass. The low vacuum condenser approach is the most promising based on the techno-economic analysis. The calculated outlet pressure of the steam turbine, the power generation capacity, the heating supply and the maximum heating area are 30KPa, 27MW, 143.58GJ/h, and 900,000 m2respectively. The expected annual income of biomass combined heat and power plants amounts up to 7,422,700 RMB.

For the wind turbine wake field in the aeolian sand environment, the multiphase flow model is used to simulate the wind sand inflow and the wake of the wind turbine is simulated and calculated in combination with the actuation line model based on the OpenFOAM-v2006. The effects of clean air inflow and wind sand inflow on the wind turbine wake field are compared, including speed loss and wake structure. Equally the particle transport in the wake of wind turbine is analyzed. The results show that the velocity of wind turbine wake recovers faster in the aeolian sand environment, the overall spatial structure is sinking, and the particles will settle in advance and distribute in strips.

In this study, monodispersed NiSe@Ni particles were successfully anchored on graphene sheets by electroless nickel plating combined with a chemical-vapor-reaction process, in which the nickel particles were first deposited onto graphene sheets and subsequently transformed in situ into NiSe@Ni at an elevated temperature. The obtained product showed a unique multi-dimensional coupling structure, namely, monodispersed NiSe@Ni particles (0 D) anchored on graphene sheets (2 D), which enabled maximum synergy on the specific surface area, conductivity, and the electrochemical activity of NiSe, Ni, and graphene multi-phases. The NiSe@Ni/graphene composite showed a specific capacity of 302 mAh g−1 at a current density of 1 A g−1 in a potassium-hydroxide-electrolyte solution. Meanwhile, the hybrid supercapacitor of NiSe@Ni/graphene//AC exhibited a high energy density of 68.0 Wh kg−1 at 803.0 W kg−1 and maintained 72.53% of the initial capacity after 10,000 cycles at a current density of 10 A g−1. [ABSTRACT FROM AUTHOR]

Iron-based particles loaded on porous carbon materials have attracted extensive attention as catalysts for denitration and desulfurization reactions. However, the carbon support of a high-temperature denitration catalyst is inevitably oxidized in the presence of H2O and O2. The mechanism of denitration catalyst oxidation and its influence on the catalytic reaction remain to be further explored. Fe2O3-loaded graphene models with carbon vacancy (Gdef), hydroxyl (HyG), and carboxyl (CyG) were constructed to investigate the effects of hydroxylation and carboxylation on the catalytic activity of Fe2O3/graphene for oxidative desulfurization and denitration by using density functional theory (DFT) calculations. According to the analysis of structural properties and adsorption energy, the adsorption process of Fe2O3 on HyG and CyG was observed to have proceeded more favorably than that on Gdef. The density-of-states (DOS) results also affirmed that HyG and CyG promote the electron delocalization of Fe2O3 around the Fermi level, enhancing the chemical activity of Fe2O3. Moreover, adsorption energy analysis indicates that hydroxylation and carboxylation enhanced the adsorption of SO2 and H2O2 on Fe2O3/graphene while also maintaining preferable adsorption stability of NO. Furthermore, mechanistic research explains that adsorbed H2O2 on HyG and CyG directly oxidizes NO and SO2 into HNO2 and H2SO4 following a one-step reaction. The results provide a fundamental understanding of the oxidized catalyst on catalytic denitration and desulfurization reactions. [ABSTRACT FROM AUTHOR]

Summary: Chemical looping combustion (CLC) between Fe2O3 and NH3 can lead to the generation of H2O, H2, NO, and N2 as the main product under different reaction stages, reasonable control of which can realize effective conversion and utilization of NH3. To initiate the CLC reaction, NH3 is chemically adsorbed on the perfect Fe2O3 surface with a hybrid between N and Fe, leading to the dehydrogenation of NH3 into *NH2 as the first reaction step. Then the second dehydrogenation step (*NH2→*NH) acts as the speed‐control step for the oxidation of NH3 into H2O and N2, leading to the reduction of Fe2O3. The reduction of Fe2O3 promotes the further adsorption of NH3, especially the intermediate species *NH2, *NH, and *N, which favors the generation of H2O and N2. Further reduction of Fe2O3 into the oxidation state lower than ~Fe2O2.25 shows lower surface oxygen potential, which is beneficial to the formation of H2 and N2. Results suggest that reasonable control of the oxidation state of iron oxide can optimize the NH3 CLC process for H2 production. [ABSTRACT FROM AUTHOR]