MOISTURE ISOTHERM CHARACTERISTICS FOR RED CHILLI

ABSTRACT

The adsorption and desorption equilibrium moisture contents for red chilli were determined experimentally in relative humidity range of 11-97% at the temperatures of 20, 30, 40 and 50°C. The effect of temperature on adsorption and desorption isotherms was found significant. Hystereses were observed for entire range of relative humidity and hysteresis loops decreased with the increase of temperature. Seven equilibrium moisture content models were fitted the experimental data at the temperatures of 20, 30, 40 and 50 °C. The modified Smith equation was the best fitted equation to the experimental data for relative humidity range of 11-97% for the adsorption and desorption isotherms for red chilli.     

Moisture Sorption Isotherm Characteristics of Freeze-Dried D-Limonene Emulsions in Modified Chitosan and Maltodextrin

This article reports on modified chitosan as an alternative substance for protecting loss of volatile compounds during freeze drying. Moisture sorption isotherms of freeze-dried D-limonene emulsions in modified chitosan were determined at 15, 25, and 35°C. The data were adjusted to the GAB model. Maltodextrin was used in a parallel experiment. Flavor released from microcapsules was measured. The monolayer humidity, the sorption heat, the diffusivity coefficients, and the surface area of freeze-dried D-limonene emulsions were determined.     

ANALYSIS OF THE DRYING OF RESIDUAL SLUDGE: FROM THE EXPERIMENT TO THE SIMULATION OF A BELT DRYER

ABSTRACT

The drying of residual sludge is a current environmental problem not sufficiently described in the literature, hence research investigations on this dewatering process are required. This paper proposes a modelling of a conveyor dryer belt. However the study of residual sludges dewatering in order to design or simulate drying equipment requires some experimental investigations. An analysis in terms of drying kinetics is proposed in this paper. Specific experiments were also needed in order to better describe some particular aspects such as crusting, shrinkage, and particle size impact. According to these data some analytical expressions have been derived and integrated in a belt dryer model. The set of air operating conditions (T, RH, v) was reduced to a single parameter, the drying potential. The results of the simulations show that a conveyor belt dryer is not well adapted to activated sludge. This is essentially due to a crust phenomenon. For a PVC industrial sludge this kind of dryer is more efficient and allows drying with reasonable residence times. Several simulations were run in order to point out the relevant parameters of the process.     

水热一步法合成矸石基吸附剂的研究

以煤矿的废弃物煤矸石为原料,研究了368 K～400 K温度范围内,煤矸石在水热体系中自转变合成了纯度和结晶度均较高的矸石基吸附剂的过程,并对其吸附性能作了初步探讨.用氮吸附静态容量法,测得该矸石基吸附剂的氮吸附等温线、比表面和孔分布曲线.通过矸石基吸附剂对苯酚的吸附实验,给出矸石基吸附剂对它的吸附等温线. 并指出合理的吸附温度、大的比表面和适当的膜化工艺对提高矸石基吸附剂的吸附量都是有效的.     

PREDICTION OF THE ASYMMETRIC PEAK PROFILE USING A MATHEMATICAL METHOD WITH A COMPETITIVE LANGMUIR ISOTHERM

The adsorption characteristics of a single component and a binary component in the stationary phase using preparative chromatography were investigated with a six-adsorption isotherm model. These analyses were based on the Langmuir model. Each parameter of the adsorption isotherm was obtained with the adsorption raw data that was calculated by frontal analysis (FA). The experimental data and the values calculated using the adsorption isotherm model were compared. The bi-Langmuir model showed good agreement for phenol while the tri-Langmuir model showed good agreement for caffeine. Each characteristic of adsorption was obtained from these results. The effect of competitive adsorption was investigated using the parameters of the adsorption isotherm model with a single component. There was good agreement between the experimental data and the calculated values.     

轻石脑油中C_6烷烃在5A分子筛上的吸附/脱附等温线研究

测定了轻石脑油中正、异构C6烷烃在5A-1分子筛上的低温(25～80℃)及高温(150～300℃)吸附/脱附等温线,分析了吸附温度、吸附压力、脱附压力对5A-1分子筛吸附/脱附性能的影响。结果表明:正己烷在5A-1分子筛上低温(25～80℃)及高温(150～300℃)下的吸附等温线均为I型吸附等温线,且随着吸附温度的升高,等温线优惠程度逐渐降低。吸附温度25℃、平衡压力7.5kPa时,异构C6烷烃在5A-1分子筛上的吸附量较小,对正己烷平衡吸附量影响不大。对于轻石脑油中的C_6烷烃来说,较适宜的吸附温度优选200～250℃,在该温度范围内,正己烷平衡吸附量为5.68～9.03g/(100g);脱附压力为1.4 kPa时,正己烷脱附量为0.69～2.35g/(100g),能够满足变压吸附的操作要求。     

有机改性蒙脱土对农药敌草隆的吸附研究

以十六烷基三甲基溴化铵(CTAB)有机改性蒙脱土为吸附剂,采用静态摇瓶试验,研究了改性蒙脱土对除草剂敌草隆的吸附行为.探讨了温度、离子强度、腐殖酸、溶液pH值对敌草隆吸附的影响.试验结果表明,CTAB改性蒙脱土对敌草隆具有较大的吸附容量,最大吸附量为20.31 mg/g吸附等温线可用Freundllich方程来描述;吸...     

大孔树脂与黄酮类化合物的固液界面吸附性能的研究

通过比较D101-A、D138、DM-130这3种大孔树脂和聚酰胺树脂对苦荞粉提取液中黄酮类化合物的静态、动态吸附及解吸性能,并研究其相应的静态吸附动力学过程和黄酮类化合物的浓度对吸附性能的影响,以选择最佳的吸附树脂。试验结果表明:D-101A、D138、DM-130大孔树脂和聚酰胺树脂这4种树脂对黄酮类化合物的吸附能力非常接近,都可用来作为黄酮类化合物的吸附剂。