Extraction of Cinnamomum longepaniculatum deciduous leaves essential oil using solvent-free microwave extraction: Process optimization and quality evaluation

The optimal process conditions for solvent-free microwave extraction(SFME)of essential oils from Cinnamomum longepaniculatum deciduous leaves after moisture conditioning were established by response surface methodology(RSM).A Box-Behnken design(BBD)was applied to evaluate the effects of three independent variables:moisture content(A:54%–74%),microwave power(B:300–500 W)and microwave time(C:20–40 min),on the extraction yield of essential oil.The compounds of the essential oils obtained by SFME,hydro-distillation and microwaveassisted hydro-distillation(MADE)were identified by gas chromatography-mass spectrometry(GC-MS),and the total lipids of C.longepaniculatum fresh leaves and deciduous leaves were analyzed.The correlation analysis of the response regression model indicated that quadratic polynomial model could be employed to optimize the extraction of essential oil.The optimal extraction condition was A:58%,B:400 W and C:28 min.In the optimal condition,the maximum extraction yield was 4.475 mL/100 g dw and higher than that by MADE.The main compound of the essential oil was eucalyptol(63.54%),and total oxygenated compounds was 78.95%,mainly caused by SFME and the metabolism of endophytic bacteria with decreasing content of phospholipids and fatty acids.Analysis of variance under the extraction condition illustrated high fitness of the model and the success of RSM for optimizing and reflecting the expected process condition.SFME combined with moisture regulation was an effective method for extracting essential oil from C.longepaniculatum deciduous leaves.

Study on microwave-assisted extraction of coal

The effect of different factors on coal extraction yield-temperature, solvent, coal type and irradiation time were investigated for different China coals under microwave-assisted extraction（MAE）. The results show that the optimum temperature for ethanol, acetone and THF are 393,373 and 373 K respectively and the extraction yield of THF is higher than that of other two solvents under MAE. Extraction with several single organic solvents were conducted for the 5 typical China coals-Shenfu, Tongchuan, Panzhihua, Yitai and Huating coal under microwave-assisted extraction and Soxhlet extraction. Results indicat that extraction yield of ethylenediamine, ethanol, acetone, tetrahydrofuran under MAE are all higher than that of Soxhlet extraction and MAE required less time. Tongchuan coal extracts of ethanol and acetone which were extracted by MAE and Soxhlet extraction were analyzed by GC/MS.

Alkaline extraction characteristics of steelmaking slag batch in NH_4Cl solution under environmental pressure

In order to obtain better carbonation effect, extraction behavior of slag batch is necessary to study. Relevant parameters like selective extraction yield were originally discussed. The relationship between selective extraction yield and conversion ratio was systemically focused on. The results show that alkaline earth metal conversion ratio is changed with leaching time and NH4CI concentration by first order exponential, and the maximum conversion for calcium keeps about 68% at 120 min in 0.4 mol/L NH4C1 solution, while leaching temperature and particle size have a linear effect on conversion ratio. Selective extraction yield of calcium is more than 93%, and the value of Mg is less than 5%. Apparent layer bands of silicon and calcium appear in the surface area through morphology detection of slag after leaching, and the case for 38-75 μm slag batch is more obvious than 75 150 μm slag and slag with larger particle size when leaching in 0.4 mol/L NH4Cl solution for 90 rain at 60 ℃.

Optimization of Response Surface of Ultrasonic-assisted Extraction of Rizhao Black Tea

[ Objectivel The aim was to determine the optimal technology for ultrasonic-assisted extraction of black tea was determined. [ Methed] Taking Black Tea as materials, the Box-Behnken response surface design method of tea polyphenols ultrasonic-assisted extraction process optimi- zation was applied. The regression optimization model of the ethanol volume fraction, ultrasonic time, and ultrasonic temperature, ethyl acetate extract stalling time and tea polyphenols was established. [ Result] The influence of four factors on the black tea polyphenol solvents affecting size was as follows： ultrasonic time 〉 ethanol volume fraction 〉 stalling extraction time 〉 ultrasound temperature. The best extraction process was ultrasonic time 80 min, volume fraction of 88.99% ethanol, extraction time 89.97 min, ultrasonic temperature of 80℃. At the optimized technical parameters, the black tea phenolic extraction yield can be as high as 73.50%. [ Conclusion] The study provided theoretical basis for the development of tea leaves and black tea.

Analysis of Influence Factors for FCC Slurry Separation by Mixed Solvent Extraction

Daqing FCC slurry was treated using mixed solvent containing N,N-dimethylformamide(extraction solvent)and n-paraffin(stripping-agent).The influence of solvent formulation(ratio of DMF/stripping-agent),temperature,time and solvent-oil ratio on yield and aromatics content of the extract oil were analyzed by a four-factor and three-level orthogonal experimental design.The polynomial regression models between the extract oil yield and aromatics content with the four factors were established.Response surface analysis showed that solvent formulation,temperature and solvent-oil ratio have significant effects on extraction result and there is an interaction between temperature and solvent-oil ratio on aromatics content,when the FCC slurry is extracted by mixed solvent.However,the extraction time has no significant effect.The optimal conditions for FCC slurry extraction covered:a solvent mixed ratio of 2.3,a temperature of 62.8℃,a solvent-oil ratio of 3.2,and a time of 35 min.The result of verification experiment was in good agreement with the prediction of the model.