Solid -liquid extraction of andrographolide from plants experimental study, kinetic reaction and model

Solid - liquid extraction is performed from leaves and stems of Andrographis paniculata in ethanol - water solvent, in order to obtain andrographolide. The first part of this work concerns the acquisition of the raw plant geometric and physicochemical characteristics. Then batch experiments are done in order to study the influences of the operating parameters (temperature, nature of the solvent and particles size). Furthermore, the destruction of the solute with high temperature is also studied. In the last part, an two-shape extraction model is proposed and compared with experimental data. This model includes the shape factor of the particles population composed of stems and leaves (cylinders and plates)

Fast batch to continuous solid-liquid extraction from plants in continuous industrial extractor

In this work, a study about solute continuous extraction from vegetable matrix is undertaken. An industrial apparatus is used and the problems are to identify information to be acquired in order to process implementation. To this end, a batch study was carried out to obtain the extraction kinetics, as well as a study of the matter behaviour under pressure and a study of raw plant transport. Finally, to couple these elements makes it possible to represent the extraction yields according to time in the apparatus. A methodology for the change from batch to continuous extractor based on laboratory tests is proposed

Development of andrographolide extraction process from andrographis paniculata nees in a pulsed column

TOULOUSE-ENSIACET (315552325) / SudocSudocFranceF

Supercritical Carbon Dioxide Extraction of Andrographolide from Andrographis paniculatu: Effect of the Solvent Flow Rate, Pressure, and Temperature

Andrographis paniculata Nees has been extensively used for traditional medicine and help against fever, dysentery, diarrhoea, inflammation, and sore throat. In this study, andrographolide, the main component of this plant was extracted from the leaves of A. paniculata using supercritical carbon dioxide. The operating pressures were varied from 7.50 to 20MPa, the temperatures were varied from 30°C to 60"C, and the flow rates were varied from 0.5 to 4mlmin-I. The best extraction condition occurred at lOMPa, 40T, and a flow rate of 2mlmK' for a 3g sample of A. paniculata ground-dried leaves. The measured extraction rate was found to be about 0.0174g of andrographolide per gram of andrographolide present in the leaves per hour of operation. The future studies must focus on the interaction between the various operating parameters such as temperature, pressure, and flow rate of supercritical carbon dioxide

Fast batch to continuous transposition : application to the extraction of andrographolide from plants

The objective of this study is to propose a fast development method for batch to continuous processes transposition. This method is based on transient regime experiments analysis and is applied to a solid liquid extraction. The application under consideration is the extraction of an active principle from plant in a non-sinusoidal pulsed column. Typically, the proposed signal is composed of two different periods: in one hand, a classical sinusoidal pulsation step used to mix the liquid and solid phases in the active part of the column and allow an optimal mass transfer and, in a second hand, an impulsion phase, used generally for the transport of solid. The extraction is carried out in a disc and doughnut column of 54 mm in diameter, and 3.5 m in height. Liquid and solid are flowing cocurrently and downwardly. This technological improvement has been implemented to solve the difficulties due to the important heterogeneity of the matter: part tends to float and other to sink, which always leads to a definitive flooding in classical operations. The effects of the solid flow rate and of the solvent characteristics on the hydrodynamic behavior of the column are studied. The mean residence time and the total solid holdup are calculated by using transient regime mass balance on experiments. These experiments allow pointing out and quantifying opposite effects of the operating parameters. Mass transfer experiments have been performed and the results fit calculated values obtained by coupling the hydrodynamic with batch extraction results. Despite of the simplification made, this validates the fast development method proposed to help the batch to continuous transposition

A new pulsation policy in disc and doughnut pulsed column applied to the solid-liquid extraction of andrographolide from plants

Classically, sinusoidal oscillations are imposed to enhance mixing and mass transfer between two phases contacted. But, in any case of solid/liquid contact, it was noticed that this pulsation mode was not efficient enough to allow a controlled behaviour of the solid phase. The problem is particularly met for the treatment of raw plants or polydispersed populations with complex physical properties. The objective of this study is to demonstrate the viability of using a non-sinusoidal pulsation in a continuous contactor to replace a traditional batch sinusoidal mode. A review of the different pulsation techniques is firstly presented. The example of solid-liquid extraction of Andrographolide from plants has then been choosen to bring out the advantages of the new pulsation mode. The development of this application as a continuous process in a column has indeed encountered difficulties due to the important heterogeneity of the matter : one of these classes tends to float and the other to sink, which always leads to a definitive flooding in classical operations. Typically, the proposed signal is composed of two different periods : in one hand, a classical sinusoidal pulsation step used to mix the liquid and solid phases in the active part of the column and allow an optimal mass transfer and, in a second hand, an impulsion phase, used generally for the transport of solid. The extraction is carried out in a disc and doughnut column of 54 mm in diameter, and 3.5 m in height. Liquid and solid are flowing cocurrently and downwardly. Experiments have been performed to know the global characteristics of the process in steady state and to suggest some elements for industrial design. The results showed that an optimal tuning of the geometric characteristics of the column, the level of interface and the parameters of the pulsation, could increase the operated domain where flooding is avoided