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[en] Highlights: • A CCHP system integrated with biomass gasification was optimized. • The optimization was based on life-cycle assessment. • The optimization involved energetic, economic, and environmental aspects. • The overall-performance criterion was obtained with TOPSIS. - Abstract: A multi-criteria optimization for a biomass gasification-integrated combined cooling, heating, and power (CCHP) system based on life-cycle assessment is carried out. The criteria comprise primary energy saving ratio (PESR), total cost saving ratio (TCSR), and CO2 emission reduction ratio (CERR). The overall-performance criterion, Cl, is obtained with Technique for Order of Preference by Similarity to Ideal Solutions (TOPSIS). Results show that the Cl reaches its maximum when the nominal electric output is 1572.8 kW, the biomass feedstock type is wood pellet, and the operation strategy is following the electric load (FEL). The PESR, TCSR, CERR, and Cl are 0.101, 0.271, 0.498, and 0.867, respectively. By comparing with reference systems, it is found that in FEL mode, the system is improved because of higher energy utilization efficiency and better use of economic and environmental advantages of biomass. In following the thermal load (FTL) mode, economic performance is compromised for optimal overall performance. Sensitivity analysis is carried out to find out the effect of variation of various parameters on optimization results. It is found that the variation of a single-aspect parameter could affect the system performance on all aspects. The variation of primary energy consumption per unit electricity from the grid (pecen,g) has the greatest effect on optimization results. The corresponding variation ranges of PESR, TCSR, and CERR owing to its variation are from −0.063/0.231/0.473 to 0.284/0.295/0.624 and from −0.029/0.101/0.314 to 0.194/0.123/0.379 in FEL and FTL modes.
[en] Highlights: • An innovative sorption system is proposed to reduce nitrogen oxides emission. • Nanoparticle of carbon coated aluminum plays dual roles in the beginning and end of this system. • The lowest annual required mass of composite sorbent is one quarter of that of urea solution. • Cost of sorption SCR system by using carbon coated aluminum is much lower than that of adblue. - Abstract: A novel sorption system is proposed to reduce nitrogen oxides (NOx) emission, which is regarded as an alternative solution to conventional urea selective catalytic reduction (SCR) technology. Nanoparticle, i.e. carbon coated aluminum (Al@C) plays dual roles at the beginning and end of this system. One is used to prepare novel fuel blend, which is expected to reduce NOx emission due to low fuel consumption. The other is selected for developing composite sorbent for ammonia storage reactor. NOx emission of a diesel engine is tested in terms of various fuel blends. Based on these testing results, working performance of novel sorption SCR system is evaluated. It is indicated that the lowest annual required mass of composite SrCl2 with Al@C is about 98 kg, which is one quarter of urea solution. Comparably, the highest annual required volume of urea solution is 25.6% higher than that of composite SrCl2 with Al@C. Annual required mass ranges from 98 kg to 475 kg whereas annual required volume is in the range from 243 L to 446 L. Feasibility of novel sorption SCR system is further verified, which reveals vast potentials for reducing NOx emission in terms of conversion efficiency and cost.
[en] Highlights: • A sorption thermal energy storage device for domestic heating is presented. • The new design scenario with valve-less adsorber and separate reservoir is adopted. • The newly developed composite sorbent of zeolite 13X/MgSO4/ENG-TSA is used. • The temperature lift is 65–69 °C at 25 °C adsorption and evaporating temperatures. • The impregnated MgSO4 dramatically accelerates the temperature rising rate. - Abstract: A sorption thermal energy storage (TES) device for domestic heating is presented in this article. The TES device adopts the new design scenario with valve-less adsorber and separate reservoir to eliminate the large-diameter vacuum valve for vapor flow, which decreases the cost, reduces the vapor flow resistance, and improves the system reliability. The device is charged by electric heater, which can add much flexibility to the building energy system as well as contribute to the valley filling and peak shaving from the demand side management. The newly developed composite sorbent of zeolite 13X/MgSO4/ENG-TSA (expanded natural graphite treated with sulfuric acid) with the salt mass fraction of 15% in the zeolite 13X/MgSO4 mixture is tested and used in the TES device (denoted as XM15/ENG-TSA). Experimental results show that the TES device with XM15/ENG-TSA has the energy storage density of 120.3 kWh m−3 at 250 °C charging temperature and 25–90 °C discharging temperature. The temperature lift is as high as 65–69 °C under the adsorption and evaporating temperatures of 25 °C. The impregnated MgSO4 dramatically improves the temperature rising rate during the adsorption heat recovery process, but the specific energy storage capacity of XM15/ENG-TSA is similar to that of zeolite 13X/ENG-TSA. The effect of the impregnated MgSO4 suggests that MgSO4 can be used for low-temperature TES to relieve the self-hindrance of the hydration reaction.