scholarly journals Wax Separated Effectively from Fischer-Tropsch Wax Residue by Solvent Desorption: Thermodynamic and Kinetic Analysis

2021 ◽  
Vol 11 (16) ◽  
pp. 7745
Author(s):  
Ling Li ◽  
Yuqi Zheng ◽  
Baokang Xu ◽  
Yanhua Xu ◽  
Zhiying Liu

The separation and recycling of effective resources in Fischer-Tropsch wax residue (FTWR) are urgent because of the environmental hazards and energy waste they bring. In this study, organic solvents are used to separate recyclable resources from FTWR efficiently, achieving the goals of “Energy Recycle” and “Fisher-Tropsch Wax Residue Treatment”. The response surface methodology (RSM) response surface analysis model accurately evaluates the relationship among temperature, residence time, liquid–solid ratio, and desorption rate and obtains the best process parameters. The results show that the product yield can reach 82.28% under the conditions of 80 °C, 4 h, and the liquid–solid ratio of 24.4 mL/g. Through the kinetic analysis of the desorption process of FTWR, the results show that the desorption process conforms to the pseudo second-order kinetic model and the internal diffusion model. The thermodynamic function results showed that there were not only van der Waals forces in the desorption process, but other strong interaction forces such as hydrogen bonds. In addition, Langmuir, Freundlich, and BET equations are used to describe the desorption equilibrium. Scanning electron microscopy (SEM) were used to analyze the pore structure of FTWR during desorption. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and Gas chromatography-mass spectrometer (GC-MS) analysis confirmed that the desorption product’s main component was hydrocarbons (50.38 wt%). Furthermore, naphthenic (22.95 wt%), primary alcohol (11.62 wt%), esters (8.7 wt%), and aromatic hydrocarbons (6.35 wt%) compounds were found and can be further purified and applied to other industrial fields. This study shows that using petroleum ether to separate and recover clean resources from Fischer-Tropsch wax residue is feasible and efficient and has potential industrial application prospects.

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Wasim Akram ◽  
Navneet Garud

Abstract Background Chicory is one of the major source of inulin. In our study, Box–Behnken model/response surface analysis (RSM) was used for the optimization of spray drying process variables to get the maximum inulin yield from chicory (Cichorium intybus L.). For this investigation, the investigational plan utilized three process variables drying temperature (115–125 °C), creep speed (20–24 rpm), and pressure (0.02–0.04 MPa). Result The optimal variables established by applying the Box–Behnken model were as follows: drying temperature 119.20 °C, creep speed 21.64 rpm, and pressure 0.03 MPa. The obtained powdered inulin by spray drying was investigated for the yield value, identification, size, and surface morphology of the particle. The inulin obtained from the spray drying process consists of a fine molecule-sized white powder. Instead, the drying methods shows a significant effect on the morphology and internal configuration of the powdered inulin, as the inulin obtained from spray drying was of a widespread and uniform size and shape, with a rough surface on increase in temperature and smoother surface while increasing the creep speed. The findings indicate that the spray drying with optimum parameters resulted in maximum product yield. Conclusion The outcomes of the study concluded that the product yield through spray drying technique under optimized condition is optimal as compared to other drying technique. Hence, this technique may be applied at commercial scale for the production of inulin.


2014 ◽  
Vol 79 (3) ◽  
pp. 361-377 ◽  
Author(s):  
Huan-Yan Xu ◽  
Wei-Chao Liu ◽  
Shu-Yan Qi ◽  
Yan Li ◽  
Yuan Zhao ◽  
...  

Kinetics and optimization on the discoloration of an active commercial dye, Argazol Blue BFBR (ABB) by heterogeneous Fenton-like reaction catalyzed by natural schorl were investigated in this study. Kinetic investigations revealed that the first-order kinetic model was more favorable to describe the discoloration of ABB at different reaction conditions than the second-order and Behnajady-Modirshahla-Ghanbery models. The relationship between the reaction rate constant k and reaction temperature T followed the Arrhenius equation, with the apparent activation energy Ea of 51.31kJ?mol-1. The central composite design under the response surface methodology was employed for the experimental design and optimization of the ABB discoloration process. The significance of a second order polynomial model for predicting the optimal values of ABB discoloration was evaluated by the analysis of variance and 3D response surface plots for the interactions between two variables were constructed. Then, the optimum conditions were determined.


2021 ◽  
Vol 2083 (4) ◽  
pp. 042060
Author(s):  
Zhongfu Bao ◽  
Dejiang Zeng ◽  
Runxi Gu

Abstract A cylinder time-delay oscillation system can be constructed by using air bag and throttle valve. The air bag and throttle valve are used to realize the time-delay transmission of pressure in the feedback circuit, and the feedback pressure is used to promote the reversing of two position five-way valve, so as to realize the reciprocating action of the cylinder. The experimental design is carried out based on the simulation analysis, and the response surface is constructed based on the experimental data to clarify the relationship between the cylinder dwell time and the main component parameters. Based on response surface, genetic algorithm is used to search for the best control parameters to realize the accurate control of cylinder dwell time.


2020 ◽  
Vol 14 (4) ◽  
pp. 572-582
Author(s):  
Soumaya Hachani ◽  
◽  
Sarah Boukhalkhal ◽  
Ziyad Ben Ahmed ◽  
Mohamed Harrat ◽  
...  

The Box-Behnken design was used to investigate the effect of three independent variables – time, temperature and solvent-to-solid ratio on the responses of total phenolics, total flavonoids, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and cupric ion reducing antioxidant capacity (CUPRAC) of date fruit methanolic extracts. Response surface analysis showed that the optimal ultrasound extraction parameters that maximized the responses were 30 min, 298 K and 74.4 ml/g. Under optimum conditions, UHPLC-DAD-MS/MS was used to tentatively characterize 11 phenolic compounds. The experimental values for the quantification of phenolic compounds and antioxidant activities are in accordance with the predicted values, indicating the suitability of the model and the success of response surface methodology in optimizing the ultrasound extraction conditions.


2021 ◽  
Vol 52 (1) ◽  
pp. 204-217
Author(s):  
Mohammed & Mohammed-Ridha

This study was aimed to investigate the response surface methodology (RSM) to evaluate the effects of various experimental conditions on the removal of levofloxacin (LVX) from the aqueous solution by means of electrocoagulation (EC) technique with stainless steel electrodes. The EC process was achieved successfully with the efficiency of LVX removal of 90%. The results obtained from the regression analysis, showed that the data of experiential are better fitted to the polynomial model of second-order with the predicted correlation coefficient (pred. R2) of 0.723, adjusted correlation coefficient (Adj. R2) of 0.907 and correlation coefficient values (R2) of 0.952. This shows that the predicted models and experimental values are in good agreement. The results of the kinetic study showed that the second-order kinetic model was in good agreement with the experimental results and suggested that the mechanism of chemisorption controlled the LVX adsorption. The experimental results indicated that the adsorption of LVX on iron hydroxide flocs follows Sips isotherm with the value of the correlation coefficient (R2) of 0.937. Sips isotherm shows that both homogenous and heterogeneous adsorption can occur.


2019 ◽  
Vol 80 (4) ◽  
pp. 685-694 ◽  
Author(s):  
Maryam Dolatabadi ◽  
Saeid Ahmadzadeh

Abstract Presence of emerging contaminants such as pharmaceutical products in aquatic environments has received high concern due to their undesirable effect on wildlife and human health. Current work deals with developing a treatment model based on the electro- Fenton (EF) process for efficient removal of metformin (MET) from an aqueous medium. The obtained experimental results revealed that over the reaction time of 10 min and solution pH of 3, the maximum removal efficiency of 98.57% is achieved where the value of MET initial concentration, current density, and H2O2 dosage is set at 10 mg.L−1, 6 mA.cm−2, and 250 μL.L−1, respectively, which is in satisfactory agreement with the predicted removal efficiency of 98.6% with the desirability of 0.99. The presence of radical scavengers throughout the mineralization of MET under the EF process revealed that the generation of •OH radicals, as the main oxidative species, controlled the degradation mechanism. The obtained kinetics data best fitted to the first order kinetic model with the rate constant of 0.4224 min−1 (R2 = 0.9940). The developed treatment process under response surface methodology (RSM) was employed for modeling the obtained experimental data and successfully applied for efficient removal of the MET contaminant from pharmaceutical wastewater as an adequate and cost-effective approach.


Proceedings ◽  
2019 ◽  
Vol 42 (1) ◽  
pp. 9
Author(s):  
Gianfranco Carotenuto ◽  
Carlo Camerlingo

Wearable electrical sensors based on zeolites can be used for breath monitoring. The high silicon content of clinoptilolite makes this type of zeolite very adequate for fabricating sensitive water sensors. In addition to sensitivity, response fastness also represents a sensor characteristic of fundamental importance for breath monitoring. Here, the response fastness of a clinoptilolite-based water sensor has been evaluated by measuring the current intensity behavior upon exposition to a constant humidity atmosphere (75%). In particular, the clinoptilolite surface has been biased with a sinusoidal signal (20 Vpp, 5 kHz), and the true-RMS current intensity value has been recorded during exposition to the constant humidity atmosphere. Since current intensity is proportional to the adsorbed water concentration (only hydrated cations are charge carriers) a kinetic analysis has been possible. The clinoptilolite dehydration kinetics in a dry atmosphere have been evaluated too. According to this kinetic analysis, water adsorption is described by a Lagergren pseudo-first-order model with a rate constant of (58.6 ± 0.9)·10−4 min−1, while desorption in dry air follows a first-order kinetic model with a specific rate of (202.7 ± 0.3)·10−4 min−1 at 25 °C.


2020 ◽  
Vol 19 (3) ◽  
pp. 623-628
Author(s):  
ZhengNan Zhao ◽  
XiangLong Yang ◽  
Maoxun Li ◽  
Fang Yu ◽  
HaiDong Liang

Purpose: To maximize the yield of extract from Eucommia ulmoides Oliver and its effect on bone quality. Methods: Different extraction indices were optimized with response surface methodology (RSM) for maximization of extract yield from Eucommia ulmoides Oliver. Box–Behnken design (BBD) was used to identify the effects of temperature, time, and liquid to solid ratio on extract yield from Eucommia ulmoides Oliver. After 4-week acclimatization, thiry-two rats were randomly assigned to 4 groups (n = 8): group 1 (sham) given vehicle only; group 2 (OVX rats given Eucommia ulmoides Oliver extract at a dose of 4 g/kg; group 3 (OVX + vehicle); group 4 (OVX + EUOE), i.e., OVX rats given Eucommia ulmoides Oliver extract (4 g/kg). Sham rats had intact ovaries. After surgery, the rats received gentamicin intramuscularly for 3 successive days. Two months after surgery, blood and trabecular bones was taken for analysis. Results: Temperature and liquid-to-solid ratio had marked impact on extract yield from Eucommia ulmoides Oliver, with the best conditions being temperature of 88 °C, time of 137 min, and liquid to solid ratio 16:1. Using these optimized conditions, the maximum yield of extract obtained experimentally (2.53%) was very close to the predicted value of 2.49 %. There was a good fit between the mathematical model evolved and the data on extract yield. The extract significantly (p < 0.01) increased the Ca and P and Cr levels in OVX + EUOE group compared to those in OVX control. Moreover, the extract significantly (p < 0.01) increased macro-mechanical indices of trabecular bone in OVX+EUOE group, relative to those in OVX control. Conclusion: The yield of Eucommia ulmoides Oliver extract has been successfully optimized using RSM. The extract exhibited strong effects on bone quality. Keywords: Optimization, Eucommia ulmoides, Box–Behnken design, Response surface methodology, Bone loss, Gene


2019 ◽  
Vol 31 (5) ◽  
pp. 1045-1048
Author(s):  
Quang Thuong Tran ◽  
Loan Thi Thanh Vu ◽  
Tram Huyen Le ◽  
Ly Thi Phuong Giang ◽  
Toyonobu Usuki

The objective of this study was to evaluate the effects of extraction parameters (ethanol concentration, extraction ratio of solvent to raw material and extraction time) on the yield of spinosin from the seeds of Ziziphus mauritiana Lam. Box-Behnken factorial design was used in association with response surface methodology. The optimal extraction conditions were an ethanol concentration of 61 %, 40 (v/w) liquid-to-solid ratio, and 2.6 h extraction time with reflux. Spinosin was purified using Diaion HP20SS as an adsorbent. The maximum spinosin yield was 1.18 mg/g raw material. Present findings can be applied to future approaches for maximizing the extraction of spinosin from Z. mauritiana Lam. seeds.


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