The storage of fluctuating renewable energy is critical
to increasing
its utilization. In this study, we investigate an energy conversion
and storage system with high energy density, called the chemical looping
solid oxide cell (CL-SOC) system, from the integrated perspectives
of redox kinetics and system design. The proposed system generates
electricity, reproduces hydrogen, and stores it via metal oxide redox
reactions in combination with a standard pressure fluidized bed reactor
and a reversible solid oxide cell (SOC). We conducted redox kinetic
analyses of Fe supported on an Fe-doped calcium titanate carrier in
redox reaction using the modified shrinking core model and determined
the scale of a fluidized bed reactor by developing the numerical Kunii–Levenspiel
reactor model. Furthermore, the SOC redox system was modeled to estimate
the round-trip efficiency and the system cost. The CL-SOC system achieved
a stable hydrogen charge and discharge rate operation (i.e., constant
redox reaction rate) in the fluidized bed reactor. It also achieved
the reduction of system cost compared to the conventional high-pressure
hydrogen storage system. In addition, the levelized cost of storage,
including electricity costs, was calculated, and the advantage was
also discussed. In this way, this study describes the integrated method
of the CL-SOC system evaluation, which will provide a guide for material
and system design.
An improved method for the quantitative analysis of isomaltooligosaccharide (IMO) products by HPLC with a polymer-based amino column was developed. The column was much higher in durability than a silica-based amino column used for the conventional method. The column durability enabled us to determine each IMO using the calibration curve of RI-detector response against a concentration of standard IMO and maltosaccharide reagents. The linear relationship between peak height of RI response and concentration of saccharide was found for glucose, maltose, kojibiose, nigerose, isomaltose, maltotriose, panose, isomatotriose, maltotetraose and isomaltotetraose. The linearity was obtained at concentrations of up to 17 mg mL, and correlation coefficients were 0.999. The slope of peak height versus concentration differed from saccharides, of which glucose was the highest while isomaltotetraose was the lowest. The relative slope of each saccharide to glucose, (slope for saccharide) (slope for glucose), referred as a conversion factor, was calculated, and the concentration of each saccharide in commercial IMO products was determined from peak height on a HPLC chromatogram by the following equation: (concentration of saccharide A, mg mL) (concentration of standard glucose, mg mL) (peak height of A) (conversion factor of A) (peak height of standard glucose). A commercial IMO product was analyzed and the result obtained was as follows: isomaltose (19.2 g), isomaltotriose (10.3 g), panose (4.9 g), nigerose (2.0 g), kojibiose (3.5 g) and isomaltotetraose (2.8 g), respectively. The total amount of the sugars identified by the improved method from IMO was higher than those determined by the conventional method, which may have resulted from the higher resolution of each saccharide. The method showed clearly the presence of nigerose and kojibiose together with four unknown components. A major unknown component was identified to be isomaltotriosylglucose by 1 H-and 13 C-NMR analyses.
Endo-ƒÀ-1,4-glucanase and ƒÀ-glucosidase from Aspergillus sp. K-27 were purified to homogeneity. Endo-ƒÀ-1,4-glucanase was a monomeric enzyme with a Mr of .21,000. Its activities for cellooligosac * Corresponding author .
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.