微波辅助提取五倍子中没食子酸的工艺研究

采用微波辅助法提取五倍子中的没食子酸。研究了料液比、微波功率、微波时间对没食子酸提取效果的影响,进行单因素试验和正交试验,确定微波提取没食子酸的优化工艺条件为：以2 mol/L的盐酸为提取剂,料液比为1/30,微波功率为230 W,提取时间450 s。微波辅助提取法和常规提取方法相比,具有更广阔的应用前景。     

没食子酸脱羧酶及酶法制备焦性没食子酸研究进展

对没食子酸脱羧酶及酶法制备焦性没食子酸研究进展进行了介绍和综述,重点介绍了产没食子酸脱羧酶的微生物种类、发酵时间、底物浓度、pH值、温度、金属离子,氮源及接种量等对微生物发酵产高活性没食子酸脱羧酶的影响因素,并简述了酶法制备焦性没食子酸的方法,指出了今后的研究方向。     

Supercritical CO2 Extraction Optimization of Onion Oil Using Response Surface Methodology

Response surface methodology was employed to optimize the conditions of supercritical CO₂ extraction of the oil from freeze‐dried onion powder. The effects of pressure, temperature and extraction time on the yield of oil were investigated. The maximum extraction yield of 4.69 ± 0.04 g/kg dry basis was achieved at a pressure of 20.6 MPa, a temperature of 40.6 °C, a time of 260 min, a CO₂ flow rate of 22 L h^–1, and an entrainer ratio of 0.1 mL absolute ethanol per gram dry basis. The chemical composition of the oil was analyzed by gas chromatography‐mass spectrometry. The most representative compounds of the essential oil were organosulfur‐containing compounds and, among these, the main constituents were methyl 5‐methylfuryl sulfide (18.30 %), methyl 3,4‐dimethyl‐2‐thienyl disulfide (11.75 %) and 1‐propenyl propyl disulfide (9.72 %).     

Optimization of Food Waste Bioevaporation Process Using Response Surface Methodology

A proven bioevaporation process was used to treat food waste (FW) by mixing ground FW with biodried sludge (BS). Organic loading (OL), moisture content (MC), and air flow rate (Q_g) showed significant influences on FW bioevaporation performance. Single-parameter experiments for MC and Q_g were conducted and ranges were determined to be 55–67 wt% and 0.04–0.14 m³/kg TS_mixture · h, respectively. In order to optimize the FW bioevaporation process, a central composite design (CCD) and response surface method (RSM) were applied over the preselected ranges of OL (0.00–0.16 kg VS_FW/kg TS_BS), MC (50.91–71.09 wt%), and Q_g (0.01–0.17 m³/kg TS_mixture · h). The results indicated that OL of 0.06 kg VS_FW/kg TS_BS, MC of 59.2 wt%, and Q_g of 0.09 m³/kg TS_mixture · h were the optimal conditions for the FW bioevaporation process. Water evaporation of 123.1% and VS degradation of 108.4% were obtained under these estimated optimal conditions.     

Optimization of Vegetal Pear Drying Using Response Surface Methodology

The aim of this work was to optimize the drying process of vegetal pear and minimize energy resources (cost) under prefixed limits involving vegetal pear moisture, color, and productivity. The optimization of vegetal pear drying was made by using response surface methodology (RSM) for minimum process cost and color difference between fresh and dried samples (moisture ≤0.10 g water g d.m.^?1). A pilot-plant dryer was used for dehydrating vegetal pear slices (0.5 cm thickness). The tests were carried out at different air temperature (60 to 70°C), samples diameter (4 to 7 cm), and pretreatment with ascorbic acid solutions (0–0.1% w/w). The optimum drying conditions were found at air temperature of 63°C with 5-cm sample diameter and 0.075% of ascorbic acid concentration. On the optimized drying conditions, dried vegetal pear presented values with moisture content of 0.052 g water g d.m.^?1, color difference of 11.65, production rate of 0.0073 kg h^?1, and total cost of $30.58/kg dried product^?1     

白兰地中没食子酸的测定

在橡木桶中陈酿的白兰地随着贮存的时间增长,没食子酸的含量会有明显的增加。文章运用高效液相色谱仪建立一种测定白兰地中没食子酸含量的方法,该方法简单快速、准确性和稳定性高、环保、检测成本低。通过研究不同档次白兰地中没食子酸的含量,有助于提高鉴别白兰地的品质。     

Optimization of Activated Carbon Preparation from Pomegranate Peel (Punica granatum Peel) Using RSM

This research involves the optimization of different variables of the operating conditions to prepare activated carbon from pomegranate peels (Punica granatum peel). For this purpose, a statistical method called Response Surface Methodology (RSM) has been adopted to economize the number of experiments and their meaningful interpretation. Activated carbon was produced by chemical activation (H₃PO₄). RSM was used to evaluate the variables considered in the preparation of activated carbon such as impregnation ratio (2–4?g H₃PO₄/g pomegranate peel), temperature (400–600°C), and activation time (30–90?min), experimented using a three-variable Box–Behnken Design (BBD) based on a quadratic model and an RSM tool provided by Design Expert 8.0.4 (STAT-EASE Inc., Minneapolis, USA). The responses analyzed for optimization were the methylene blue number and the iodine number. The factors that are significant influencing the activated carbon preparation have been identified by an analysis of variance (ANOVA). The optimum conditions established were impregnation ratio of 2.78, activation temperature of 575°C, and activation time of 73?min.     

Aqueous Two-Phase Extraction of Lactic Acid: Optimization by Response Surface Methodology

In this study a suitable alcohol/salt aqueous two-phase (ATP) system was selected for the recovery of lactic acid from an aqueous solution. From the different ATP systems studied, the ethanol/dipotassium hydrogen phosphate ATP system appeared to be favorable. To examine the potential of this ATP system, the extraction yield of lactic acid in aqueous solutions was optimized with the response surface methodology. The parameters studied were concentrations of ethanol (22.00–38.80%, w/w), dipotassium hydrogen phosphate (15.00–31.80%, w/w) and lactic acid (26.36–93.64 g/L). The optimum conditions were found to be 30.23% w/w ethanol, 18.40% w/w dipotassium hydrogen phosphate, and 80 g/L lactic acid. Under these conditions, a favorable extraction yield of lactic acid was obtained. The maximum partition coefficient of lactic acid and extraction yield was determined as 2.26 and 87%, respectively. The optimum extraction conditions were then used to guide the recovery of lactic acid from a real fermentation broth. As a result, the partition coefficient and extraction yield of lactic acid reached 2.06–80%, respectively.     

Optimization of the operating parameters using RSM for the Fenton oxidation process and adsorption on vegetal carbon of MO solutions

This study focused on the application of RSM on the Fenton process and the adsorption of vegetal carbon (VC) to obtain the optimal conditions for the minimization of the colored synthetic wastewater. Methyl orange (MO) with an azo dye was used as the model organic compound. Fenton processes were investigated to establish the optimal conditions. The Fe²⁺/H₂O₂ ratio was studied to establish the major MO degradation when 100 and 200 mg/L of MO were treated. For the adsorption process, to determine the optimal conditions, the principal variables studied were the vegetal carbon mass dosage, degradation time and dye concentration.     

芒果叶中没食子酸的提取研究

通过离子化萃取分离法提取了芒果树叶中没食子酸,采用单因素实验和正交试验,考察了浸提温度、NaHCO3浓度、溶剂倍量和浸提时间对芒果叶中没食子酸提取率的影响。结果表明提取没食子酸的最佳工艺条件是：浸提温度为100℃,NaHCO3浓度0.16%,溶剂倍量（mL/g）为90,浸提时间为60min,在此条件下没食子酸提取率为1.74%。     

Reactive Extraction of Levulinic Acid Using TPA in Toluene Solution: LSER Modeling,Kinetic and Equilibrium Studies

Abstract

Levulinic acid, a carboxylic acid containing ketone structure, is a clear to brownish semi‐solid melting at 37°C; soluble in alcohol, ether, and chloroform, levulinic acid can be used as an acidulant in foods and beverages. Organic solutions of amines are being used increasingly to separate organic acids from aqueous mixture solutions by reactive extraction. The design of an amine extraction process requires kinetic data for the acid–amine+solvent system used. Kinetic studies for the extraction of levulinic acid from aqueous solution with tripropylamine (TPA) diluted in toluene were carried out using a stirred cell for kinetic studies. Equilibria for levulinic acid extraction by TPA in toluene as a diluent have been determined. All measurements were carried out at 298.15 K. The equilibrium data were also interpreted by a proposed mechanism of complexation by which (1∶1) and (2∶1) acid‐amine complexes are formed. Kinetics of extraction of levulinic acid by TPA in toluene has also been determined. The results of the liquid‐liquid equilibrium measurements were correlated by a linear solvation energy relationship (LSER).     

Optimization of Phospholipid Nanoparticle Formulations Using Response Surface Methodology

The present study deals with the optimization of phospholipid liposome formulations to mimic red blood cells. Optimization of different concentrations of distearylphosphatidylcholine, dipalmitoylphosphatidylcholine, and phosphatidylserine at a fixed concentration of lecithin and Tween^® 80 was done using response surface methodology. The optimized formulation produced liposomes with a particle size in the range of 112–196 nm. The optimized formulation shows low encapsulation efficiency at low levels of insulin but increases at higher loading levels. Formulated vesicles fulfill the size requirement for intravenous drug delivery. The present system is environmentally friendly with respect to biodegradability and biocompatibility.     

Ultrasound-Assisted Extraction of Carnosic Acid and Rosmarinic Acid Using Ionic Liquid Solution from Rosmarinus officinalis

Ionic liquid based, ultrasound-assisted extraction was successfully applied to the extraction of phenolcarboxylic acids, carnosic acid and rosmarinic acid, from Rosmarinus officinalis. Eight ionic liquids, with different cations and anions, were investigated in this work and [C₈mim]Br was selected as the optimal solvent. Ultrasound extraction parameters, including soaking time, solid–liquid ratio, ultrasound power and time, and the number of extraction cycles, were discussed by single factor experiments and the main influence factors were optimized by response surface methodology. The proposed approach was demonstrated as having higher efficiency, shorter extraction time and as a new alternative for the extraction of carnosic acid and rosmarinic acid from R. officinalis compared with traditional reference extraction methods. Ionic liquids are considered to be green solvents, in the ultrasound-assisted extraction of key chemicals from medicinal plants, and show great potential.     

H2S Reactive Absorption from Off‐Gas in a Spray Column: Insights from Experiments and Modeling

H₂S removal from an off‐gas stream was performed in a spray column by H₂S reactive absorption into a NaOH solution. The individual and interactive effects of three independent operating variables on the percentage of absorbed H₂S were investigated: the initial pH of the scrubbing solution, the initial scrubbing solution temperature, and the volumetric liquid‐to‐gas ratio. The optimum operating variables were determined by response surface methodology (RSM) attaining a percentage of absorbed H₂S of 98.7 ± 0.2 %. Additionally, the process performance was modeled by an artificial neural network (ANN) to predict the percentage of absorbed H₂S. The results showed that the experimental data agreed better with the ANN model than with the RSM results.     

三烷基胺萃取丙酸的动力学特性

为研究胺类萃取剂萃取有机酸的动力学行为 ,以丙酸稀溶液为分离溶质 ,三烷基胺 ( 730 1)为萃取剂 ,正辛醇和煤油的混合物为稀释剂 ,采用恒界面池法考察了萃取剂和溶质浓度、搅拌速率、两相接触面积、温度等操作参数对丙酸萃取动力学的影响。结果表明 :730 1萃取丙酸为准一级反应萃取过程 ;且萃取发生在相界面 ,即界面反应萃取机制 ;表观活化能为 2 8.5kJ/mol,萃取速率受温度的影响不显著 ;经计算 ,在一般的萃取塔操作条件下 ,该体系的萃取过程为反应和传质过程的混合控制。     

Optimization of Microwave-Vacuum Drying of Button Mushrooms Using Response-Surface Methodology

Button mushrooms (Agaricus bisporous) were dried in a microwave-vacuum dryer up to a final moisture content of around 6% (d.b.). The effect of microwave power level (115 to 285 W), system pressure (6.5 to 23.5 kPa), and slice thickness (6 to 14 mm) on drying efficiency and some quality attributes (color, texture, rehydration ratio, and sensory attributes) of dehydrated mushrooms were analyzed by means of response surface methodology. A rotatable central composite design was used to develop models for the responses.Analysis of variance showed that a second-order polynomial model predicted well the experimental data. The system pressure strongly affected color, hardness, rehydration ratio, and sensory attributes of dehydrated mushrooms. A lower pressure during drying resulted in better quality products. Optimum drying conditions of 202 W microwave power level, 6.5 kPa pressure, and 7.7 mm slice thickness were established for microwave vacuum drying of button mushrooms. Separate validation experiment was conducted at the derived optimum conditions to verify the predictions and adequacy of the models.     

A Hybrid Method for Stochastic Performance Modeling and Optimization of Chemical Engineering Processes

As chemical engineers seek to improve plant safety, reliability, and financial performance, a wide range of uncertaintyladen decisions need to be made. It is widely agreed that probabilistic approaches provide a rational framework to quantify such uncertainties and can result in improved decision making and performance when compared with deterministic approaches. This article proposes a novel method for design and performance analysis of chemical engineering processes under uncertainty. The framework combines process simulation tools, response surface techniques, and numerical integration schemes applied in structural reliability problems to determine the probability of a process achieving a performance function of interest. The approach can be used to model processes in the presence or absence of performance function(s), with or without parameter interactions, at both design and operational phases. With this, process behavior can be quantified in terms of stochastic performance measures such as reliability indices and the associated most probable process design/operating conditions, providing a simple way to analyze a wide range of decisions. To validate the applicability of the proposed framework, three case study systems are considered: a plug flow reactor, a heat exchanger, and finally a pump system. In each case, performance criteria based on the original physical model and the surrogate model are set up. Reliability analysis is then carried out based on these two models and the results are assessed. The results show that the proposed framework can be successfully applied in chemical engineering analysis with additional benefits over the traditional deterministic methods.     

Optimization of supercritical fluid extraction of linseed oil using RSM

The objective of the present study was to develop a supercritical fluid extraction (SFE) method, suitable for extraction of total oil content from linseed, and to be used as a preparative technique for fatty acid determination. Optimum conditions (volume of added ethanol as a co‐solvent, dynamic extraction time (DET), and pressure) were predicted in order to obtain the maximum yield of the extract. Response surface methodology (RSM) and central composite rotatable design (CCRD) were used for modeling the process. Variable values ranged as follows: co‐solvent 0–1 mL, DET 36–60 min, and pressure 45.57–62.05 MPa (6000–9000 psi). Effects of co‐solvent volume and extraction pressure were well described by simplified polynomial equation (R² = 0.85), since DET had no significant influence (p>0.05) on the extract yield. The maximum yield of oil, calculated from experimental results, was obtained with 1 mL of co‐solvent, and pressure of 62.05 MPa. Optimized conditions were used for extraction of oil from four samples of linseed, ground to pass through 1, 2, 3, and 4 mm‐sieve, to determine adequate granulation for SFE. Finally, results for yield and fatty acid composition of the extract obtained using SFE were compared with the results of Soxhlet extraction. Practical applications: The obtained extracts can be used for fatty acid analysis, since they have not been damaged and their fatty acid compositions have not been degraded by reagents or aggressive extraction conditions. It is shown that the selection of appropriate milling equipment for grinding of samples is necessary to achieve adequate granulation and avoid fractionation of sample.     

Regeneration of spent catalyst from vinyl acetate synthesis as porous carbon: Process optimization using RSM

Optimization of the process of regeneration of spent catalyst from vinyl acetate synthesis was attempted using response surface methodology (RSM) based on the central composite design (CCD). The optimization was performed to maximize the response variables of methylene blue (MB) adsorption capacity as well as the yield of the porous carbon, with the process variables being regeneration temperature, regeneration duration and steam flow rate. The two factor interaction model and quadratic model were developed to correlate the process variables with the response variables. Based on the analysis of variance (ANOVA), all the three process parameters were found to be significant. The optimized process conditions were identified to be activation temperature of 946 °C, activation time of 30 min and steam flow rate of 2.4 g min⁻¹ with MB adsorption capacity of 420 mg/g and a yield of 50.7%. The MB adsorption capacity as compared with the majority of the literature reported values, along with high yield of the regenerated carbon, certify the economic feasibility of the process, with potential application in variety of liquid phase adsorption processes.     

MMA反应萃取生产工艺的开发

提出反应萃取方法生产ＭＭＡ的新工艺，选择二甲苯为萃取剂，经过实验考评，证实此工艺能解决ＭＭＡ生产中存在的ＭＭＡ、ＭＡＡ高温自聚和因酯化为可逆反应所造成的ＭＭＡ单程收率较低等问题，提出一错流反应萃取工艺，并以此为背景建立了能描述此过程的模型，且进行了模拟，为ＭＭＡ反应萃取连续化工艺设计提供了依据。