煤制烯烃含盐废水近零排放技术的应用

与石油、天然气相比，我国煤炭资源更加丰富，发展新型煤化工产业是大势所趋。煤炭和水资源的逆向分布导致煤化工企业所在地水环境问题尤为突出。常规处理工艺难以实现废水达标排放和资源回用目标，需通过特定的近零排放技术工艺，将浓盐水进一步浓缩至盐结晶，产水全部回用，结晶盐外排作为固废处置。本文结合工程实例，介绍了某煤化工项目针对生产过程中产生的含盐废水所采取的近零排放处理工艺技术路线，其主要由含盐废水膜处理单元和浓盐水蒸发结晶单元组成。采用机械蒸汽压缩循环、强制循环降膜蒸发、高效传热和盐种等技术，同时对蒸发结晶近零排放系统进行改进和优化。装置实际运行结果表明：各项工艺参数指标及药剂和能源消耗量均达到设计要求，产水水质达到优质再生水回用标准，实现整套装置长周期稳定运行及废水近零排放目标。     

Recent developments in catalyst synthesis using DBD plasma for reforming applications

The catalyst has a significant role in gas processing applications such as reforming technologies for H₂ and syngas production. The stable catalyst is requisite for any industrial catalysis application to make it commercially viable. Several methods are employed to synthesize the catalysts. However, there is still a challenge to achieve a controlled morphology and pure catalyst which majorly influences the catalytic activity in reforming applications. The conventional methods are expansive, and the removal of the impurities are major challenges. Nevertheless, it is not straightforward to achieve the desired structure and stability. Therefore, significant interest has been developed on the advanced techniques to take control of the physicochemical properties of the catalyst through non-thermal plasma (NTP) techniques. In this review, the systematic evolution of the catalyst synthesis using NTP technique is elucidated. The emerging DBD plasma to synthesized and effective surface treatment is reviewed. DBD plasma synthesized catalyst performance in reforming application for H₂ and syngas production is summarised. Furthermore, the status of DBD plasma for catalyst synthesis and proposed future avenues to design environmentally suitable and cost-effective synthesis techniques are discussed.     

Experimental investigation on the cracking of pre-combustion cracking gas with gliding arc discharge plasma

To improve the quality of pre-combustion cracking gas, the gliding arc discharge plasma is adopted in this paper. The influence of incoming flow rate, electrode gap distance and discharge frequency on cracking effect have been experimentally studied. The results show that through plasma cracking, the concentration of H₂ increases while the concentration of CH₄ and C₂H₄ decrease. With different fuel ratio conditions, the variation trend of C/H ratio as well as the mass flow of carbon and hydrogen atoms in the cracking products vary from each other. The cracking effect becomes weaker with the increase of incoming flow rate, while is better when the fuel ratio is larger. Given the flow rate of 18slpm and 24slpm, the best cracking effect can be acquired with the electrode gap of 1.5 mm. Besides, the effect of gliding arc discharge plasma cracking is weakened as the discharge frequency rises.     

Structures and properties of chicken myofibrillar protein gel induced by microwave heating

Structures and properties of myofibrillar protein gel prepared at different power (300–800 W) were evaluated. Amino acid analysis demonstrated that changes in microwave power did not alter primary structure of gel. However, an increase in microwave power could change higher structures of gel. As microwave power increased, α-helix content decreased and β-sheet content increased. Increased microwave power probably facilitated protein to unfold and expose the internal groups, causing surface hydrophobicity and the formation of disulphide bonds were enhanced, which indicated changes in tertiary and quaternary structures of protein. At 500 W, gel had the best ultrastructure where surface morphology, springiness and water holding capacity reached the optimum. Our findings suggested that microwave at an appropriate power (500 W) could change higher structures of myofibrillar protein gel to achieve desired processing and quality protein gel characteristics.     

Effect of lactose content on dielectric properties of whole milk and skim milk

Dielectric properties (dielectric constant ε′ and dielectric loss factor ε′′) of whole milk and skim milk with the lactose content of 4.56–6.44% and 4.57–6.47%, respectively, were measured over the frequency range of 20–4500 MHz at 25 °C using a vector network analyzer. The results showed that ε′ decreased with increasing frequency, and ε′′ changed with V shape and its minimum was noted at about 2000 MHz. Whole milk had lower dielectric properties than skim milk at almost same lactose content and a given frequency. ε′ had weak positive linear relationship with lactose content for whole milk, but had negative linear relationship for skim milk. No matter for which milk, ε′′ had very good negative linear relationship with lactose content below 1000 MHz and had good positive linear relationship above 2300 MHz. The study provides information on developing rapid lactose detector for milk in future.     

Ultrafast fabrication of nanostructure WO3 photoanodes by hybrid microwave annealing with enhanced photoelectrochemical and photoelectrocatalytic activities

Tungsten oxide (WO₃) nanoplate films with a relatively rough surface were successfully fabricated via a simple hydrothermal method, followed by the hybrid microwave annealing (HMA) treatment only a few minutes for the first time. The microscopic morphology and phase were characterized by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), Raman spectrum and X-ray diffraction (XRD). Photoelectrochemical measurements demonstrated that the obtained WO₃ film of microwave processing for 11 min exhibited the photocurrent density of 1.60 mA/cm² at 1.2 V (vs. Ag/AgCl) and the IPCE value of 55% at 355 nm under an applied voltage of 1.0 V (vs. Ag/AgCl), which were about 3 and 2.5 times compared with the WO₃ film prepared by the conventional annealing method, respectively. Moreover, the WO₃-HMA films were applied to the versatile photoanode-driven photoelectrochemical system for CO₂ reduction into formic acid. The maximum formic acid generation rate and faradaic efficiency of the WO₃-HMA films were 9.21 μmol h^?1 cm^?2 and 45.45%, respectively. This study provided a facial and rapid method to synthesize the high-performance WO₃ photoanodes with better photoelectrochemical and photoelectrocatalytic activities.     

Comparison of microwave and high-pressure processing on bound phenolic composition and antioxidant activities of sorghum hull

The influence of microwave boiling (MB treated 5, 10 and 15 s was abbreviated as MB5, MB10 and MB15, respectively) and high-pressure boiling (HB processed 10, 20 and 30 min was denoted as HB10, HB20 and HB30, respectively) processing on the composition and content of bound phenolic substances of sorghum hull and their antioxidant capacity were evaluated. Nine bound phenolic profiles were identified by HPLC-ESI-MS/MS, including syringic acid, veratric acid, p-hydroxybenzonic acid, caffeic acid, sinapic alcohol, ascorbic acid, prenylnaringenin and luteolin. Compared with traditional hot water processing (HP treated 10, 30 and 50 min was abbreviated as HP10, HP30 and HP50, respectively), the content of free procyanidins and total phenolics of sorghum hull treated with HB increased by 35.92–58.87% and 6.20–18.70%, respectively. Sorghum hull treated with HB20 possessed the highest ABTS (ABTS radical scavenging capacity) and FRAP (ferric ion reducing antioxidant power) among all treatment groups.     

非相变固体蓄热材料的蓄放热特性

搭建了低谷电蓄能蒸汽发生换热测试系统，采用数据记录仪、Hot Disk热常数分析仪等仪器检测了刚玉球等非相变固体蓄热材料的热物性。通过实验与模拟相结合的方式，研究了粉煤灰、氧化镁、刚玉砂、刚玉球等材料的蓄放热特性。分析了蓄热材料种类和粒径大小对蓄放热特性的影响，得到了不同材料的蓄热密度和综合换热系数等关键参数。结合FLUENT非稳态模拟方法，模拟了蓄热体在不同材料粒径下的蓄热和放热温度场变化规律。结果表明：刚玉球能够提供充足连续的热量，可以作为一种性能良好的蓄热材料进行应用；随着刚玉砂粒径的增大，其蓄热密度和综合换热系数会增大，有效放热时间也会延长。     

Chromatic processing for feature extraction of PD-induced UHF signals in GIS

Partial discharge (PD) detection is an effective means of discovering insulation faults in gas-insulated switchgear (GIS). One of the most extensively used methods in PD detection has historically been the ultrahigh frequency (UHF) method. This study evaluates the chromatic processing methodology and its key factors for feature extraction of UHF signals in GIS. Three types of artificial defects are installed in the GIS tank at 0°, 90°, and 180°, respectively. The features of the UHF signals are extracted in the chromatic space, and PD discrimination of the defects is achieved. The influences of processors are studied before the feature selections are suggested. The time-stepping method is proposed to determine the rules of UHF signal frequency characteristics that vary with time. Finally, the process and options of the chromatics-inspired methodology are summarized.