Xing Cao,Ruiqi Zhang,Ning Zhang,Lei Chen,Dongming Chen,Xuebing Li
Organic phase change materials (PCMs) such as fatty acids and fatty alcohols are often trapped by inherent low thermal conductivity for thermal energy storage in buildings. The present study is devoted to ameliorating this problem from an innovative perspective of introducing bio-sourced additive. To promote performance of binary eutectic PCM comprising lauric acid (LA) and 1-hexadecanol (HD), the composite PCMs are developed, where the powdered seashell waste is added as thermal enhancer, and their thermo-physical properties are characterized via DSC, FT-IR, SEM, TGA, cooling curve analysis, accelerated thermal cycling test together with thermal conductivity measurement. Meanwhile, the impacts of two particle sizes, five mixing ratios between two different sizes and two modification approaches of seashell powder (SP) are surveyed meticulously. Experimental results turn out that 80-mesh SP and 300-mesh SP are both capable of providing greater thermal conductivity when dispersed in LA-HD eutectic PCM, and the enhancement level of thermal conduction is even higher for composite PCM containing 300-mesh SP than for composite PCM containing TiO 2 powder. Besides, the thermal conduction ability is strengthened to the maximum extent when 80-mesh SP and 300-mesh SP are combined at mass ratio of 3:7, while the same situation also occurs when seashell powder is treated by high-temperature calcination. The resultant composite PCM possesses encouraging melting temperature and melting enthalpy, and its thermal stability and reliability are well approved. Therefore, we conclude that the seashell powder has the expectable competence to realize performance improvement of organic PCM for application in buildings for thermal energy storage.
Jinkai Shu,Bozhi Ren,Wei Zhang,An Wang,Sen Lu,Shuyu Liu
Modified Shell Powder/La-Fe-TiO2(La-Fe-TiO2@MSP) composites were fabricated using the sol-gel method and characterized by SEM, XRD, UV-vis DRS and photocurrent techniques, and their physicochemical and optical properties were analyzed. The effects of various factors on the photocatalytic degradation of pyridine and its reaction kinetics were investigated by batch experiments using pyridine, a typical nitrogen-containing heterocyclic compound in coal chemical wastewater, as the target removal species. The pyridine degradation rate of 80.23% was obtained for 800 mg/L composite solution by photocatalytic oxidation of 50 mg/L pyridine wastewater for 180 min at 35 °C, pH = 8 and light intensity of 560 W. The photocatalytic degradation performance was optimal. The quenching experiments determined that the active species of photodegradation were mainly hole and hydroxyl radicals, and the photocatalytic degradation mechanism was analyzed in this way.Keywords:La-Fe-TiO2@MSP;photocatalysis;pyridine;reaction kinetics
Wang Zheng,Wang Yan-Shi,Tong Zhuang,Deng Qin,Luo Sheng-Xu
This paper reports the formation of novel adsorbent material based on undulating venus shell (UVS), white conch shell (WCS), conus conch shell (CCS) and abalone shell (AS). These absorbent materials were prepared by grinding the shells followed by high-temperature calcination process.
The prepared adsorbents were well characterized by scanning electron microscopy (SEM), X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy. Further, the effects of adsorbent dosage and temperature on the adsorption of Cd2+ by shell powder and related adsorption
isotherms were evaluated. The results indicated that the amount of adsorbent and temperature have a great influence on the adsorption process of the four adsorbents. Under optimized conditions, the four shell powders exhibited strong adsorption properties of Cd2+ which was consistent
with the Freundlich isotherm adsorption model. The optimal conditions for preparing shell powder adsorbents with the best adsorption performance were determined by evaluating the particle size, calcination temperature and calcination time during the preparation process and the prepared materials
were characterized by several techniques. The results demonstrated that the particle size of UVS powder was over 140 mesh at 450 °C with activation time of 60 min. Furthermore, the UVS powder exhibits apparent porous morphology after calcination and thus the specific surface area was markedly
increased. Consequently, the adsorption performance was significantly improved.
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