气体喷射筛板萃取塔的滞液率和气含率

以水和蒽醌法生产过氧化氢的工作液为研究物系,在内径为50mm的筛板萃取塔内,模拟工业操作条件,研究了空气水蒽醌工作液三相物系的分散相滞液率和气含率.讨论了气相、分散相和连续相流速对分散相滞液率和气含率的影响,并提出了用于预测气液液三相萃取系统的分散相滞液率和气含率的关联式.结果表明,滞液率关联式的预测值与实验结果的平均相对偏差为7.3%,气含率关联式的预测值与实验结果的平均相对偏差为7.1%.

气体扰动萃取及反应萃取集成在过氧化氢合成中的应用研究

在自行设计的气体扰动萃取塔中,以水、蒽醌工作液为实验物系,进行了H2O2的气体扰动萃取、蒽醌氢化液的氧化与蒽醌氧化液的萃取集成过程的实验。结果表明:在一定萃取比范围内,在相同分散相流量下,萃取剂用量对H2O2的萃取率影响很小;填料塔内的气体扰动萃取率比液液萃取率提高2～3倍;蒽醌氢化液的氧化与蒽醌氧化液的萃取过程集于一塔内进行是可行的。实验结果为蒽醌法合成H2O2的新型萃取工艺提供了依据。

气体搅拌萃取过氧化氢实验研究

在内径为50mm的筛板塔内，研究了空气-水-葸醌工作液三相体系萃取过氧化氢过程。萃取温度为40℃，空气和分散相的表观流速分别为（1.31～3．22）×10^-3m·s^-1和（1．27～1．70）×10^-3m·s^-1，分散相和连续相的表观流速之比为50：1。结果表明。在普通液．液萃取过氧化氢过程中引入气体作搅拌，可减小分散相的液滴直径，增大相际接触面积，明显提高萃取效率，降低萃余相中过氧化氢的含量。传质单元高度随气体表观流速的增加而降低，传质系数随气体表观流速的增加而增大。

气体扰动萃取过氧化氢的试验研究

在内径为50mm的筛板塔内，研究了蒽醌工作液-过氧化氢-水体系的气体扰动萃取过程。萃取温度为40℃，空气和分散相的表观流速分别为（0～3．22）mm／s和（1．27～1．70）mm／s，分散相和连续相的表观流速之比为50：1。结果表明，在过氧化氢萃取塔中引入扰动气体，增大了分散相滞液率，提高了总板效率，降低了萃余相中过氧化氢的含量。

超临界流体萃取技术在食品工业中的应用

本文阐述了超临界流体萃取技术在食品工业中的应用,提出了存在的问题,以期为超临界流体萃取技术的进一步应用提供参考。

Supercritical Fluid Extraction of Essential Oil from Dry Rhizome of Ligusticum chuanxiong Hort and Their Characterization by GC/MS

Supercritical fluid extraction (SFE) of essential oil from dry rhizome ofLigusticum chuanxiong Hort was developed. GC/MS was used for the determination of the composition ofessential oil. Forty-four compounds were identified. The conventional extraction method wasconducted in parallel for comparison. The extracts were qualitatively compared by GC/MS. The yieldsof SFE and steam distillation-extraction were 4.16 % ( v/w) and 0.8 % ( v/w), respectively.Application of SFE of zessential oil from dry rhizome of Ligustiaan chuanxiong Hort was preferable.

GAS技术制备PCS纳米微粒

初步研究了GAS技术在PCS纳米微粒制备上的应用。着重研究了不同溶剂体系与超临界CO2的相互作用及其对超临界CO2气体抗溶剂结晶过程的影响,对平衡时间及初始浓度对所得纳米粒子粒径和粒径分布的影响进行了探索性研究,获得了粒径20~60 nm,分散度小于0.5的PCS纳米粒子。

Influences of the [Co^2＋]/[Co^3＋] Ratio on the Process of Liquid-phase Oxidation of Toluene by Air

Liquid phase oxidation of toluene is an environmental benign route for the production of benzoic acid.In a φ48mm bubble column reactor,the commercial process of toluene liquid phase oxidation was conducted with Co(CH3COO)2.4H2O as catalyst.The Co2+ concentration [Co2+] was determined by extraction spectrophotometry and hereby the Co3+ concentration [Co3+] was obtained by mass balance.The results showed that [Co3+] reached the maximum at about 25-30min.[Co3+] increased with increasing Co catalyst amount at total Co concentration<150 mg.L-1 of toluene.The conversion of toluene,yield and selectivity of benzoic acid increased with the increasing [Co3+/Co2+] max.A high [Co3+] and a high [Co3+]/[Co2+] ratio are beneficial to the reaction.

Mechanism and experiment of substituting high drainage roadway with directional long drilling group to extract pressure-relief gas

By establishing the numerical model in the vertical plane and the similar model in the horizontal plane of gas flow in goaf, the influence of high drainage roadway or drilling on the gas seepage field was analyzed, and the extraction mechanism was clarified. On this basis, the academic thought of directional long drilling group instead of high drainage roadway was put forward. And then using complex function theory, the permeation mechanical model of drilling group with circle distribution in the mining-induced fracture zone was established to explore the coupling relationship between the drilling quantity, extraction volume and the equivalent extraction rate of single drilling. Finally, combined with the concrete geological production conditions, the main parameters of directional long drilling group were determined. The distance between the drilling group center and the air-return roadway is 24 m, the height is 18 m, and the three drillings are in an approximate equilateral triangle distribution with a space of 8 m. The equivalent extraction square is 4.15 m2. It is shown that the effect of directional long drilling group is evident. The gas content in the upper comer is controlled below 0.95%, the content in the tail roadway is kept below the alarm value, and the content is over 50% in the drill, realizing the secure and effective extraction of coal and gas.

Solid phase microextraction(SPME) sampling under turbulent conditions and for the simultaneous collecting of tracer gases

Solid phase microextraction （SPME） is a solvent-flee method of sample collection. SPME is an appealing method for sample collection because it is designed for the sampling of trace level analytes with short sampling times in a variety of environments. Additionally, SPME can be used to directly deliver a sample to a gas chromatograph （GC） for analysis by means of thermal desorption. In this paper, the performance of SPME under dynamic conditions was investigated. Additionally, the competence of SPME sampling for the simultaneous analysis of multiple trace analytes was also evaluated. This work is discussed in the context of underground mine ventilation surveys but is applicable to any industry in which ventilation circuits must be evaluated. The results of this paper showed that the performance of the 100 ~m PDMS SPME fiber was both precise and rapid under dynamic conditions. This SPME fiber was also able to simultaneously collect sulfur hexafluoride （SF6） and perfluoromethylcyclohexane （PMCH） with adequate sensitivity.

Diethylstilbestrol in Fish Tissue Determined Through Subcritical Fluid Extraction and with GC-MS

As the key point in sex hormone analysis, sample pre-treatment technology has attracted scientists' attention all over the world, and the development trend of sample preparation forwarded to faster and more efficient technologies. Taking economic and environmental concerns into account, subcritical fluid extraction as a faster and more efficient method has stood out as a sample pre-treatment technology. This new extraction technology can overcome the shortcomings of supercritical fluid and achieve higher extraction efficiency at relatively low pressures and temperatures. In this experiment, a simple, sensitive and efficient method has been developed for the determination of diethylstilbestrol(DES) in fish tissue using subcritical 1,1,1,2-tetrafluoroethane(R134a) extraction in combination with gas chromatography-mass spectrometry(GC-MS). After extraction, freezing-lipid filtration was utilized to remove fatty co-extract. Further purification steps were performed with C_(18) and NH_2 solid phase extraction(SPE). Finally, the analyte was derived by heptafluorobutyric anhydride(HFBA), followed by GC-MS analysis. Response surface methodology(RSM) was employed to optimizing the extraction condition, and the optimized was as follows: extraction pressure, 4.3 MPa; extraction temperature, 26℃; amount of co-solvent volume, 4.7 m L. Under this condition, at a spiked level of 1, 5, 10 μg kg^(-1), the mean recovery of DES was more than 90% with relative standard deviations(RSDs) less than 10%. Finally, the developed method has been successfully used to analyzing the real samples.

Novel Gas-assisted Three-liquid-phase Extraction System for Simultaneous Separation and Concentration of Anthraquinones in Herbal Extract

Gas-assisted three-liquid-phase extraction(GATE), which has the advantages of both three-liquid-phase extraction and solvent sublation, is a novel separation technique for separation and concentration of two organic compounds into different phases in one step. This highly effective and economically applicable method has been developed for separating emodin and rhein from herbal extract. In a GATE system composed of butyl acetate/PEG4000/ammonium sulfate aqueous solution, influence of various parameters including gas flow rate, flotation time, salt concentration, initial volume of PEG and butyl acetate was investigated. Within 50 min of 30 ml·min-1nitrogen flow, removal ratio of emodin and rhein from aqueous phase could be over 99% and 97%, respectively.Mass fraction of emodin in the BA phase and rhein in the PEG phase could reach 97% and 95%, respectively. It is demonstrated that gas bubbling is effective for partitioning of emodin and rhein into butyl acetate and PEG phase respectively, and dispersed PEG and butyl acetate could be captured from the aqueous solution. Experimental results show that GATE could be an effective and economical technology for concentration and separation of co-existed products in medicinal plants.

Prospects for petroleum mass spectrometry and chromatography

Several recently developed analytical techniques, based on high-end mass spectrometry and chromatography, for dealing with challenges in petroleum characterization are reported. Folded flight path time-of-flight mass spectrometry provides resolving power up to 100000, enabling accurate mass measurement for molecular formula determination with high confidence. Atmos- pheric pressure chemical ionization （APCI） can be used in both gas chromatography （GC, as APGC） and liquid chromatog- raphy （LC） for analyzing non-polar hydrocarbons as well as polar compounds. The improvement in chromatography facilitates the mass spectrometric analysis through online coupling. Comprehensive two-dimensional gas chromatography （GCxGC） re- solves overlapping components, rendering accurate identification and quantitation. Supercritical fluid extraction has been de- veloped as an alternative method to replace traditional solvent extraction methods and eliminate the use of large volumes of solvents that can be harmful to health and environment. Supercritical fluid chromatography （SFC） has been developed as a convergence of GC and LC chromatographic techniques. The use of SFC for heavy oils and residua has been demonstrated. Prospective developments in the use of mass spectrometric and chromatographic methods for petroleum characterization are also described.