基于响应面法中BBD法和CCD法的丙烷回收参数优化对比

为优化丙烷回收工艺运行参数,以丙烷回收率和单位综合能耗为响应值,采用响应曲面法中的Box-Behnken设计(BBD)和中心复合设计(central composite design, CCD)试验优化工艺参数,从方差分析、帕累托图分析、响应面分析和优化结果 4个方面优选最佳试验方法。结果显示,CCD法建立的二次响应回归模型的显著性优于BBD法,且CCD法响应曲面分析参数交互作用的显著性结果与方差分析一致。CCD法优化得到的最佳工艺如下:脱乙烷塔压力为3 250 kPa,低温分离器温度为-55.6℃,液相回流比为98%,丙烷回收率为98.1%,单位综合能耗为114.1 kgce/10~4 m3(1 kgce=29.307 6 MJ)。在最优工艺参数条件下,丙烷回收率增加了4.36%,产品收益达到3.548万元/d,且预测误差均小于0.2%。

BBD-RSM法优选蛋黄油软膏的制备工艺研究

目的优选蛋黄油水包油型(O/W)和油包水型(W/O)软膏的制备工艺。方法通过干馏法提取蛋黄油,以颜色、硬度、皮肤涂抹均匀性等考察因素综合评分为指标,采用Box-Behnken设计-响应面法(BBDRSM)优选最佳成型工艺。结果优选出的O/W型软膏的处方为:十八醇2.94 g,白凡士林2.59 g,十二烷基硫酸钠0.20 g,甘油1.24 g,蒸馏水10 g,蛋黄油2.55 g;W/O型软膏的处方为:液状石蜡3.87 g,硬脂酸0.25 g,蜂蜡1.62 g,硼砂0.09 g,水1.65 g,石蜡1.3 g,蛋黄油1.32 g。结论采用最佳制备工艺制备的O/W型与W/O型蛋黄油软膏成型性能优良,涂抹性好。O/W型软膏较W/O型软膏颜色较浅且油腻感低,显微镜下油滴分布较均匀且密集。该制备工艺简单可行,稳定可靠,适用于工业化生产。

旋风分离器内置导流叶片结构参数优化研究

为研究旋风分离器内置导流叶片各个结构参数之间的相互作用,基于CFD数值模拟方法和BBD试验设计,采用二阶多项式基函数建立了Stairmand旋风分离器的叶片轴向位置、叶片长度及叶片偏转角度与分离效率及压降间的数学模型。拟合结果表明:响应目标的决定系数均在0.99以上,表明相关性和回归模型效果较好。使用Design Expert软件处理数据后选择了最佳推荐点,对分离器结构进行了优化。优化后的模型与原结构对比结果如下:优化模型的压降略有上升;颗粒直径在1~20μm范围内时,优化前后分离器的分离效率变化明显,尤其在1~15μm范围内时,优化前分离效率为6.8%~31.0%,优化后则达到了17.0%~54.0%,提升约20个百分点;而当粒径在15~40μm区间时,优化前后的分离效率变化不明显,尤其是在粒径20~40μm时,优化前的分离效率为71.0%~98.0%,而优化后的分离效率只有77%~99%,提升约10个百分点;优化后的模型性能符合“高效低阻”的设计目标。所得结论可为旋风分离器内置叶片的改进提供设计指导。

PB-BBD响应面法优化全金属水力振荡器性能的研究

目前从各类水力振荡器的现场应用看,普遍存在压耗偏大的问题,使钻井液辅助破岩的能力降低。基于自激涡流振荡的原理,设计了一种全金属水力振荡器,为充分发挥其性能,降低压耗,需对振荡器内部结构进行优化。通过Plackett-Burman设计对内部各结构参数进行了筛选试验,确定显著影响参数为射流道宽度、工具厚度和出口直径,再用Box-Behnken Design响应面法对显著影响参数进行分析,得到全金属水力振荡器内部结构参数的优化组合为射流道宽度14 mm、工具厚度41.432 mm、出口直径为46 mm,最后通过数值分析验证了优化方法的有效性。

Deformation prediction and analysis of underground mining during stacking of dry gangue in open-pit based on response surface methodology

Deformation prediction and the analysis of underground goaf are important to the safe and efficient recovery of residual ore when shifting from open-pit mining to underground mining.To address the comprehensive problem of stability in the double mined-out area of the Tong-Lv-Shan(TLS)mine,which employed the dry stacked gangue technology,this paper applies the function fitting theory and a regression analysis method to screen the sensitive interval of four influencing factors based on single-factor experiments and the numerical simulation software FLAC3D.The influencing factors of the TLS mine consist of the column thickness(d),gob area span(D),boundary pillar thickness(h)and height of tailing gangue(H).The fitting degree between the four factors and the displacement of the gob roof(W)is reasonable because the correlation coefficient(R2)is greater than0.9701.After establishing29groups that satisfy the principles of Box-Behnken design(BBD),the dry gangue tailings process was re-simulated for the selected sensitive interval.Using a combination of an analysis of variance(ANOVA),regression equations and a significance analysis,the prediction results of the response surface methodology(RSM)show that the significant degree for the stability of the mined-out area for the factors satisfies the relationship of h>D>d>H.The importance of the four factors cannot be disregarded in a comparison of the prediction results of the engineering test stope in the TLS mine.By comparing the data of monitoring points and function prediction,the proposed method has shown promising results,and the prediction accuracy of RSM model is acceptable.The relative errors of the two test stopes are1.67%and3.85%,respectively,which yield satisfactory reliability and reference values for the mines.

Effects of Influencing Factors on Fenton Oxidation of Antibiotic Pharmaceutical Wastewater by a Statistical Design Approach

A series of batch-scale experiments were completed to investigate the effects of operational parameters on chemical oxygen demand (COD) removal by Fenton reagent for antibiotic pharmaceutical wastewater (APW). The significance of five operational factors including the mass ratio of H2O2/COD (g/g), the mole ratio of H2O2/Fe2+ (mol/mol), initial pH, oxidation temperature T, and reaction time t were evaluated statistically by Box-Behnken design (BBD). It was found that the five parameters were all significant to the COD removal efficiency by t-test, as well as the interactions between mass ratio/reaction time and oxidation temperature/reaction. The optimal COD removal efficiency (89.50%) was achieved when the mass ratio of H2O2/COD and the mole ratio of H2O2/Fe2+ were 3.00 and 5.00 respectively, with pH value of 3.68 at 298K for 72min reaction. A quadratic regression model with 0.9907 regression coefficient (R2) was developed which had good agreement to the experimental data.

Numerical simulation of effects of operating conditions on the molecular weight of polypropylene using a response surface method

A L463^5 Box-Behnken design was used for developing a model to predict and optimize the molecular weight （Mw ） of polypropylene （PP） ; a second-order polynomial regression equation was derived to predict responses. The significance of variables and their interactions were tested by means of the ANOVA with 95% confidence limits; the standardized effects were investigated by Pareto chart, the optimum values of the selected variables were obtained by analyzing the response surface contour plots. The optimized Mw value of 1. 217 × 10^5 g/mol was very close to the industrial value （ （ 1.22 ±0. 004） ×10^6 g/tool） at the optimum values.

Extraction process in Chuantieling(CTL) based on the quality by design(QbD) concept

Objective This study aimed to design and optimize the water extraction process for Chuantieling(喘贴灵,CTL)based on the concept of quality by design(QbD).Methods The single-factor experiments were used to select the best experimental points of CTL water extraction.On this basis,the transfer rate of ephedrine hydrochloride and sin-apine thiocyanate,and the yield of the extract were evaluated as the evaluation indicators.The liquid-solid ratio,extraction time,and pH value were selected as the main factors to carry out the Box-Behnken design(BBD).A mathematical model of the critical process parameters(CPPs)and critical quality attributes(CQAs)was established,the interaction between CQAs and CPPs was examined,and the CTL extraction process design space was established and optimized,which guaranteed the stability of the process.The high performance liquid chro-matography(HPLC)was used to analyze the main active compounds in the CTL extract.Results Through single-factor experiments,the best experimental parameters were found to be a liquid-solid ratio of 8∶1,extraction time of 90 min,pH value of 4,and extraction times of three.The experimental variance analysis results of the BBD showed that the P value of the re-gression model was less than 0.05,and the lack-of-fit value was greater than 0.01,indicating that the constructed model had good predictive ability.The operating space of the CPPs of the CTL water extraction process was combined with the actual production situation.In the pro-duction situation,the best extraction process was nine times of water addition,72 min of ex-traction time,and 4.5 of pH value.The HPLC results showed that the peak areas of ephedrine hydrochloride,sinapine thiocyanate,tetrahydropalmatine,methyl eugenol,cinnamaldehyde,and 6-gingerol in the CTL extract accounted for 0.94%,14.32%,0.78%,31.23%,0.34%,and 0.44%of the total peak area,respectively.Conclusion The water extraction process design space of CTL based on QbD was conducive to actual production operations,ensuring the stability of the process.

A quick evaluation model for CO_2 flooding and sequestration

CO2 flooding not only triggers an increase in oil production,but also reduces the amount of CO2 released to the atmosphere （by storing it permanently in the formations）.It is one of the best ways to use and store CO2.This paper firstly selects the key factors after analyzing the factors influencing the CO2 storage potential in the formations and oil recovery,and then introduces a series of dimensionless variables to describe reservoir characteristics.All influencing factors with varying values are calculated through a Box-Behnken experimental design.The results are interpreted by a response surface method,and then a quick screening model is obtained to evaluate the oil recovery and CO2 storage potential for an oil reservoir.Based on the evaluation model,sensitivity analysis of each factor is carried out.Finally,research on CO2 sequestration and flooding in a typical reservoir indicates that the evaluation model fits well with the numerical simulation,which proves that the evaluation model can provide criteria for screening attractive candidate reservoirs for CO2 sequestration and flooding.

Parametric optimization of friction stir welding process of age hardenable aluminum alloys-ANFIS modeling

A comparative approach was performed between the response surface method(RSM) and the adaptive neuro-fuzzy inference system(ANFIS) to enhance the tensile properties, including the ultimate tensile strength and the tensile elongation, of friction stir welded age hardenable AA6061 and AA2024 aluminum alloys. The effects of the welding parameters, namely the tool rotational speed, welding speed, axial load and pin profile, on the ultimate tensile strength and the tensile elongation were analyzed using a three-level, four-factor Box-Behnken experimental design. The developed design was utilized to train the ANFIS models. The predictive capabilities of RSM and ANFIS were compared based on the root mean square error, the mean absolute error, and the correlation coefficient based on the obtained data set. The results demonstrate that the developed ANFIS models are more effective than the RSM model.

Study on the Effect of Preparation Parameters of K₂CO₃/Al₂O₃Sorbent on CO₂Capture Capacity at Flue Gas Operating Conditions

In this paper, study on the effect of preparation conditions of K2CO3/Al2O3 sorbent was done. Box-Behnken design was applied to study the influence of four parameters involve initial solution concentration, impregnation time and calcination step temperature and time. A quadratic model was used to correlate the sorbent capture capacity. The model was used to calculate the optimum conditions for preparing sorbent. From the analysis of variance (ANOVA), the most influential factor on each experimental design response was identified. The potassium-based sorbents used in this study were prepared by impregnating K2CO3 on Al2O3 support. The CO2 capture capacity was measured in the presence of H2O in a fixed-bed reactor at CO2 capture temperature of 60°C using breakthrough curves. The optimum sorbent prepared by this method showed CO2 capture capacity of 77.21 mg CO2/g sorbent. It was observed that the experimental values obtained were in good agreement with the values predicted by the model, with relatively small errors between the predicted and the actual values. The results obtained in this study can be used as basic data for study on design and operating condition optimization of CO2 capture process using these sorbents.

BBD法优化固定填料床曝气去除水中氯代烷烃

采用Box-Behnken Design(BBD)法进行了固定填料床曝气工艺去除水中氯代烷烃的中心组合试验,以三氯甲烷、四氯化碳为例,研究了气水比、进水流量、初始浓度对污染物去除率的影响。试验结果表明,上述3个因素对三氯甲烷去除率有较为显著的影响,而对四氯化碳去除率的影响很小。建立的两种污染物回归模型与实际试验结果均拟合较好,具有统计学意义。上述3个因素对三氯甲烷去除率影响的交互作用较四氯化碳明显,因此重点分析了对三氯甲烷去除效果的交互作用。对于三氯甲烷以及四氯化碳而言,当气水比分别为15和14、进水流量分别为2和4.8 L/min、初始浓度分别为0.258和0.0092 mg/L时为最优工况,此时模型预测的去除率分别为89.8%、100%,二者误差均在可接受范围内。

β-Cyclodextrin inclusion complex： preparation, characterization, and its aspirin release in vitro

In this work, the optimal clathration condition was investigated for the preparation of aspirin-β-cyclodextrin （Asp-β-CD） inclusion complex using design of experiment （DOE） methodology. A 3-level, 3-factor Box-Behnken design with a total of 17 experimental runs was used. The Asp-β-CD inclusion complex was prepared by saturated solution method. The influence on the embedding rate was investigated, including molar ratio of β-CD to Asp, clathration temperature and clathration time, and the optimum values of such three test variables were found to be 0.82, 49C and 2.0 h, respectively. The embedding rate could be up to 61.19%. The formation of the bonding between -COOH group of Asp and O-H group of β-CD might play an important role in the process of clathration according to FT-IR spectra. Release kinetics of Asp from inclusion complex was studied for the evaluation of drug release mechanism and diffusion coefficients. The results showed that the drug release from matrix occurred through Fickian diffusion mechanism. The cumulative release of Asp reached only 40% over 24 h, so the inclusion complex could potentially be applied as a long-acting delivery system.

Optimization of Solid-Phase Extraction Conditions for Perfluorooctanoic Acid in Leachate

In order to optimize the solid phase extraction(SPE)conditions of perfluorooctanoic acid(PFOA)in the raw leachate and treated leachate,the effects of activator properties,SPE cartridge,p H value,ionic strength,and eluent properties were studied through single factor experiments.The optimal results of each single factor were obtained.Considering that the concentration of PFOA in the treated leachate is lower than that of the raw leachate,the SPE conditions of the treated leachate have been further optimized.Based on the above single-factor experiment,the main influencing factors were screened out as the volume of activator,ionic strength,and volume of eluent,and the three-factor threelevel response surface methodology(RSM)was optimized.The optimum SPE conditions of PFOA from treated landfill leachate were as follows:Activation of weak anion exchange(WAX)cartridge with 10 mL methanol,dosage of 600 mg KCl,6 m L 1%ammonia methanol eluted PFOA,the theory recovery rate is over95.67%.It has been verified that the error between the predicted value and the actual extraction recovery is small and has good repeatability.

Optimization of sugar production from Durian seeds via alkaline hydrolysis for second-generation bioethanol production

As one way to eliminate the issues found in the preceding generation,feedstock exploration in second-generation bioethanol production remains an issue,especially for a tropical country such as Indonesia.From exotic fruit by-products,durian holds a promising perspective that rests on its abundance,superb carbohydrate content and limited usage until now.This work presents the first-ever utilization of durian seeds for sugar production under optimized conditions through alkaline hydrolysis.A simple form of sugar was extracted by varying four parameters,namely substrate loading,NaOH concentration,hydrolysis time and hydrolysis temperature.Response surface methodology based on the Box-Behnken design was employed to outline the most optimum parameter values.Analysis of variance revealed that the quadratic model fit the data appropriately with the order of significance as substrate loading>hydrolysis time>NaOH concentration>hydrolysis temperature.The optimized conditions for reducing sugar yield,as high as 2.140 g/L,corresponded to<50 g/L substrate loading,0.522 M NaOH,60 minutes of hydrolysis time and 80oC hydrolysis temperature.The possible ethanol content of 1.094 g/L was also expected under optimized conditions,demonstrating great potential in second-generation bioethanol production.

Rain tree(Samanea saman)seed oil:Solvent extraction,optimization and characterization

The present investigation reports the soxhlet assisted solvent extraction technique to derive the oil from seeds of the rain tree.The optimization of the factors affecting the extraction process has been carried out by Response Surface Methodology(RSM)technique,and a Box-Behnken Design(BBD)consisting of three process variables has been developed to optimize the yield of oil.Using the RSM technique,the predicted optimum oil yield of 11.15%at an optimized condition of powder weight of 20 g,volume of solvent of 380 mL,and extraction time of 6 h.The physiochemical properties of the oil showed liquid greenish-yellow with 0.88,1.473 of specific gravity and refractive index,respectively.Similarly,the moisture content,free fatty acid,acid value,saponification value,iodine value,and peroxide value were found to be 0.16%,13.615,27.23,187.1 mg KOH per g oil,65.8 g I_(2) per 100 g,and 4.02 meq O_(2) per kg,respectively.From the obtained results,it was found that the extracted oil could be used for various applications.