Thermodynamic performance of a mid-temperature solar fuel system for cooling, heating and power generation

Experimental Analyses on Feasibility of Chemical‐Looping CoO/CoAl2O4 with Additive for Solar Thermal Fuel Production

“…Ther eaction rate of the looping materials with DME decreases slightly with the increase of H 2 O/DME. One of the reasons is that because Equations (12) and (14) are waterproducing reactions,a nd the increase in the partial pressure of H 2 Od ecreases the reactionr ate.I na ddition, ah igh H 2 O/ DME ratio may cause the formation of aw ater film on the surface of the looping materials,w hich prevents the contact between the fuel gas and the solid loopingm aterial. Hence, as atisfactory H 2 O/DMEi sa pproximately 1.0.…”

“…ture solar heat can be released as high-temperature thermal energy.N otably,t his upgrade of the energy level of solar heat is dependent on a" driving force": the difference of the energy level from the hydrocarbonf uel to Me. [11][12][13] Thus,S -CLC has three advantages:1 )the solar heat of 623-723 Ki s upgraded into chemical energy in the reduction reactiono f the metal oxide.2 )This type of mid-temperature solar process differs completely from the conventional energy transformation of solar heat at such moderate temperatures by heat transfer, in which the quality of the solarh eat is destroyed and the energy level is thus degraded. 3) Theupgraded solar heat stored in the metal is released in the oxidation of the metal at high temperatures.I nthis case,t he released solar heat can be further combined with advanced thermal cycles such as ag as turbinec ombined cycle,i nsteado ft he relatively low temperature of the steam cycle.T hus,t he expected achievable conversion efficiency of solar energy into power would be 30 %.…”

“…3) Theupgraded solar heat stored in the metal is released in the oxidation of the metal at high temperatures.I nthis case,t he released solar heat can be further combined with advanced thermal cycles such as ag as turbinec ombined cycle,i nsteado ft he relatively low temperature of the steam cycle.T hus,t he expected achievable conversion efficiency of solar energy into power would be 30 %. [11,12] Thed evelopment of suitable looping materials with high reactivity,s trong selectivity,a nd high regeneration ability is paramount for the chemical-looping combustion (CLC) process.Agreat effort has been put into the development of loopingm aterials that containm ainly Ni-, Co-, Mn-, Fe-, and Cu-based materials. [6,[14][15][16] These important resultsh ave shown that the reactivity and the redox stability for as ingle metal oxide should be further improved.…”

“…[26,27] Previously,w ep roposed as olar thermal fuel that uses solar-drivenD ME-based CLC. [12,28] In the reduction reactor, solar heat at approximately 773K is used to drive the endothermic reduction of CoO/CoAl 2 O 4 as the chemical-looping material. TheD ME acts as areducing agent and is converted into syngas.I nt his case,t he solar heat at approximately 773 Ki su pgraded to the chemical energy associated with the reduced Co/CoAl 2 O 4 .H ere,t he equilibrium temperature is approximately 473 K, which corresponds to the complete reduction of CoO to Co by DME at atmospheric pressure.W e compared the reactivityo fF e-, Ni-, and Co-based oxygen carriers with DME as the hydrocarbon fuel to determinea n appropriate looping material for this mid-temperature S-CLC process.…”

A solar assisted polygeneration system integrating methane reforming and chemical looping combustion with zero carbon emission

“…At the aspects of integration system structure, Zhang et al (Zhang et al 2016) designed a trigeneration system that the concentrated solar heat at approximately 350°C is utilized to drive the CLC, and the annually average efficiency of Wang and Fu, Journal of Thermal Science and Technology, Vol.12, No.1 (2017) solar-fuel-power can be about 21%, with approximately 5 percentage points higher than that of solar thermal power system. Jafarian et al (Jafarian et al 2014b) proposed a novel hybrid solar CLC, in which the oxygen carrier particles in the CLC system is utilized to provide solar thermal energy storage, and it achieve a solar fraction of up to 60% while providing sufficient storage to achieve continuous base-load power generation.…”