We report an alkoxy radical process for the C–C bond cleavage and functionalization of unstrained tertiary and secondary cyclic alcohols. In the absence of a chlorine atom, the readily available iron ...catalysts Fe(OBu-t)3 or Fe(acac)3/t-BuONa facilitate alkoxy radical formation via the direct ligand-to-metal charge transfer of Fe alkoxide and further enable the ring opening and amination of cyclic alcohols. The remote amino carbonyl compounds could be obtained with a broad scope in up to excellent yields under the mildly redox-neutral system. Light-driven electron transfer, alkoxy radical formation, and subsequent C–C bond cleavage via β-scission were the keys to the transformation.
Main observation and conclusion
While polystyrene is widely used in daily life as a synthetic plastic, the subsequently selective degradation is still very challenging and highly required. Herein, we ...disclose a highly practical and selective reaction for the catalytically efficient oxidation of alkyl aromatics (including 1°, 2°, and 3° alkyl aromatics) to carboxylic acids. While dioxygen was used as the sole terminal oxidant, this protocol was catalyzed by the inexpensive and readily available ferric compound (FeCl3) with irradiation of visible light (blue LEDs) under only 1 atmosphere of O2 at room temperature. This system could further facilitate the selective degradation of polystyrene to benzoic acid, providing an important and practical tool to generate high‐value chemical from abundant polystyrene wastes.
We report a photoinduced FeCl3‐catalyzed protocol to facilitate the oxidation of alkyl aromatics (including 1°, 2°, and 3° alkyl aromatics) as well as polystyrene to carboxylic acids using dioxygen as the sole terminal oxidant under mild conditions.
The integrated energy system (IES) optimal scheduling under the comprehensive flexible operation mode of pumping storage is considered. This system is conducive to the promotion of the accommodation ...of wind and solar energy and can meet the water, electricity and heat needs of coastal areas far away from the energy center. In this study, the joint dispatch between double pumped storage power stations is used to accommodate wind and solar energy better and smooth their fluctuations on the grid. Through the scheduling of water between the high and low reservoirs of double pumped storage power stations and the reservoir of the seawater desalination plant, the impact of storage capacity constraints on pumped storage power plants is reduced. Moreover, the objective function to build the IES optimization scheduling model is to achieve minimum economic cost. The results reveal that the integrated energy system accommodates all wind energy and solar energy. As such, the system increases the average working time of the pumped storage unit by 1.9 hours and reduces the economic cost by 31.50%. Based on the simulation results, the model can enhance the accommodation capability of wind energy and solar energy and improve the system economy.
Abstract
The optimal scheduling problem of integrated energy system (IES) has the characteristics of high-dimensional nonlinearity. Using the traditional Grey Wolf Optimizer (GWO) to solve the ...problem, it is easy to fall into a local optimum in the process of optimization, resulting in a low-quality scheduling scheme. Aiming at the dispatchability of electric and heat loads, this paper proposes an electric and heat comprehensive demand response model considering the participation of dispatchers. On the basis of incentive demand response, the group aggregation model of electrical load is constructed, and the electric load response model is constructed with the goal of minimizing the deviation between the dispatch signal and the load group aggregation characteristic model. Then, a heat load scheduling model is constructed according to the ambiguity of the human body's perception of temperature. On the basis of traditional GWO, the Fuzzy C-means (FCM) clustering algorithm is used to group wolves, which increases the diversity of the population, uses the Harris Hawk Optimizer (HHO) to design the prey to search for the best escape position, and reduces the local The optimal probability, and the use of Particle Swarm Optimizer (PSO) and Bat Optimizer (BO) to design the moving modes of different positions, increase the ability to find the global optimum, so as to obtain an Improved Gray Wolf Optimizer (IGWO), and then efficiently solve the model. IGWO can improve the defect of insufficient population diversity in the later stage of evolution, so that the population diversity can be better maintained during the entire evolution process. While taking into account the speed of optimization, it improves the algorithm's ability to jump out of the local optimum and realizes continuous deep search. Compared with the traditional intelligent Optimizer, IGWO has obvious improvement and achieved better results. At the same time, the comprehensive demand response that considers the dispatcher's desired signal improves the accommodation of new energy and reduces the operating cost of the system, and promotes the benign interaction between the source and the load.
The noncovalent interactions of ammonium ion with multidentate oxygen-based host has never been reported as a reacting center in catalytic reactions. In this work, we report a reactivity enhancement ...process enabled by non-covalent interaction of ammonium ion, achieving the C-H functionalization of polyethylene glycols with acrylates by utilizing photoinduced co-catalysis of iridium and quinuclidine. A broad scope of alkenes can be tolerated without observing significant degradation. Moreover, this cyano-free condition respectively allows the incorporation of bioactive molecules and the PEGylation of dithiothreitol-treated bovine serum albumin, showing great potentials in drug delivery and protein modification. DFT calculations disclose that the formed α-carbon radical adjacent to oxygen-atom is reduced directly by iridium before acrylate addition. And preliminary mechanistic experiments reveal that the noncovalent interaction of PEG chain with the formed quinuclidinium species plays a unique role as a catalytic site by facilitating the proton transfer and ultimately enabling the transformation efficiently.
In order to promote multi-energy complementation and low carbonization, an optimal scheduling model of virtual power plant (VPP) with carbon capture and waste incineration considering power-to-gas ...coordination is proposed. By introducing the collaborative utilization framework with a carbon capture plant-power to gas (P2G)-gas unit system, the CO2 in the carbon capture can be used as the raw material of P2G, which produces natural gas to be supplied to the gas unit. In addition, the power consumption of the carbon capture and the flue gas treatment can be transferred through joint dispatching to smooth the fluctuation of renewable energy output, so that the wind power and photovoltaic can be indirectly dispatchable and flexibly utilized. In view of the high dimensional nonlinearity of the proposed optimization model and the difficulty in solving it, a new Gaussian compound differential evolution algorithm is designed to solve the model. The simulation results show that the proposed model and method can provide peak load shifting capacity and improve renewable energy consumption, effectively reducing the cost and carbon emission of VPP.
•A new triple cascade gas turbine waste heat recovery system based on supercritical CO2 Brayton cycle.•Evaluated the performance of an integrated system combining a gas turbine and a triple cascade ...cycle.•Analyze and optimize the system's thermodynamic and economic performance.
A new triple cascade waste heat recovery system coupled with a supercritical CO2 power cycle and transcritical CO2 regenerative cycle is proposed for the high temperature exhaust waste heat generated during the operation of gas turbine, and thermodynamic and economic models are established to analyze the performance of the system, with the following performance indicators: the net output power is 5.67 MW, the thermal efficiency is 24.94 %, the exergy efficiency is 46.08 %, the total investment cost rate is 126.06$/h, and the per unit energy cost is 6.31$/GJ. The thermal performance of the integrated system consisting of the gas turbine unit and the proposed triple cascade waste heat recovery system is evaluated, and the results show that the integrated system effectively utilizes the waste heat compared with the gas turbine unit alone, while the net output power of the integrated system is 22.17 MW and the thermal efficiency is 47.7 %. Each component's exergy and cost analysis is performed. The heat exchanger accounts for a large percentage of the exergy destruction, and the investment cost rate of the turbine, compressor and other work-making components is high, indicating the direction of system optimization. The sensitivity analysis of the system's key parameters was carried out through the control variables method to reveal the influence of individual setting parameters on the system performance. Based on the research range of the set parameters, the system is optimized with multiple objectives, and the net output power, exergy efficiency and per unit energy cost are selected as the objective functions. The optimization results show that the combination of exergy efficiency and per unit energy cost resulted in better economic performance, with exergy efficiency of 50.37 % and per unit energy cost of 4.66$/GJ. Comparing the system with the other two configurations proves the superiority of the proposed system.
