Gas purification using membrane gas absorption processes

Owing to the increasing energy demand and the abundance of low quality natural gas reservoirs containing high percentages of CO2, considerable attention is given to the bulk removal of CO2 and upgrading of low quality natural gas. The main goal in doing so is to increase the heating value of natural gas and to reduce the transportation cost

PHARMACEUTICAL ANALYTICAL STUDY OF KAMPAVATARI RASA - AN AYURVEDIC HERBO MINERAL FORMULATION

Kampavatari Rasa (KVR) is a unique Ayurvedic herbo- mineral formulation mentioned in the classics Rasa Raj Sundar in Vata vyadhi and indicated mainly in Kampavata which resembles Parkinson's disease. The line of treatment in Ayurveda is to combat Vata dosha and to sustain neuronutrition by Rasayana remedies, which can be achieved by Kamapavatari Rasa with its properties like Tridosh shamaka and Rasayana. The present study was executed to establish a finger print for this unique formulation which can be used further for drug standardization. Kampavatari rasa is prepared by triturating Tamra bhasma and Rasa Sindura in equal quantity with Katuki swaras (Picrohiza kurroa) for 21 times. Each ingredient was prepared according to the norms of Ayurvedic classical texts. Raw drugs were selected on bases of Grahya lakshana and its percentage. To ensure the proper preparation of Tamra bhasma, standard tests (Bhasma Pariksha), XRD, NPST and SEM were carried and for Rasa sindura NPST test and XRD were employed. After been complied these tests KVR was prepared and subjected for physico chemical analysis and quantitative analysis of Mercury, Sulphur and Copper by ICPAES. The study of Kampavatari Rasa revealed that its Loss on Drying - 3.4%, Total Ash - 48 %, Acid insoluble ash -13%, water soluble ash - 9.5%, Hardness test was 7kg/cm2 and Tablet disintegration test 14/min which are within the normal limits and ICP – AES shows the percentage of Copper 20.51, Sulphur 8.9, and Mercury 20.43. This is the first study to establish the characterization of Kampavatari rasa

Hollow fiber membrane contactor as a gas-liquid model contactor

Microporous hollow fiber gas-liquid membrane contactors have a fixed and well-defined gas-liquid interfacial area. The liquid flow through the hollow fiber is laminar, thus the liquid side hydrodynamics are well known. This allows the accurate calculation of the fiber side physical mass transfer coefficient from first principles. Moreover, in the case of gas-liquid membrane contactor, the gas-liquid exposure time can be varied easily and independently without disturbing the gas-liquid interfacial area. These features of the hollow fiber membrane contactor make it very suitable as a gas-liquid model contactor and offer numerous advantages over the conventional model contactors. The applicability and the limitations of this novel model contactor for the determination of physico-chemical properties of non-reactive and reactive gas-liquid systems are investigated in the present work. Absorption of CO 2 into water and into aqueous NaOH solutions are chosen as model systems to determine the physico-chemical properties for non-reactive and reactive conditions, respectively. The experimental findings for these systems show that a hollow fiber membrane contactor can be used successfully as a model contactor for the determination of various gas-liquid physico-chemical properties. Moreover, since the membrane contactor facilitates indirect contact between the two phases, the application of hollow fiber model contactor can possibly be extended to liquid-liquid systems and/or heterogeneous catalyzed gas-liquid systems

Clinical effect of Suvarna Bindu Prashan

The quest for excellence in mental and physical health is not new. We find various references and formulations in Ayurvedic classics meant for promoting mental and physical health of a child. Suvarna Prashan is one of the formulations explained in age old Ayurvedic classic Kashyap Samhita. This formulation is very widely used now days as a memory and immune booster for children. But there is very little systematic documented study which can be used to evaluate the efficacy of the formulation. Suvarna Bhasma was prepared in Ayurved Rasayani Pharmacy, Pune. Madhu and Ghrita were collected from KLE Ayurveda Pharmacy, Belgaum. Suvarna Bindu Prashan was prepared in KLE Ayurved pharmacy, Belgaum. It contains Suvarna Bhasma, Ghrita and Madhu. Twenty apparently healthy male and female children with age group of three to four years were ready to sign inform consent form were selected into two groups each. Subjects in Group A received Suvarna Bindu Prashan where as Group B (Control group) did not receive any treatment. Both the groups were observed for six months. Children in Suvarna Bindu Prashan group showed significant reduction in the scores of eating habits, behavior, mood, temperament and scores of event of illness. However there was no significant difference in the score of sleeping habit. There was significant increase in IQ percentage

Atmospheric CO 2

The scope of these studies is to evaluate the ambient CO2 capture abilities of the membrane contactor system in the same conditions as leaves works during photosynthesis, such as ambient temperature, pressure and low CO2 concentration, where the only driving force is the concentration gradient. The polysulfone membrane was made by phase inversion process and characterized by ESEM micrographs which were used to determine the thickness, asymmetry and pore size. Besides, the porosity of the membrane was measured from the membrane and polysulfone density correlation and hydrophobicity was analyzed by contact angle measurements. Moreover, the compatibility of the membrane and absorbent solution was evaluated, in order to exclude wetting issues. The prepared membranes were introduced in a cross flow module and used as contactor between the CO2 and the potassium hydroxide solution, as absorbing media. The influence of the membrane thickness, absorbent stirring rate and absorption time, on CO2 capture were evaluated. The results show that the efficiency of our CO2 capture system is similar to stomatal carbon dioxide assimilation rate

Mathematical modelling and numerical simulation of CO2/CH4 separation in a polymeric membrane

YesCO2 capture from natural gas was experimentally and theoretically studied using a dead-end polymeric permeation cell. A numerical model was proposed for the separation of CO2/CH4 using Polytetrafluoroethylene (PTFE) in a flat sheet membrane module and developed based upon the continuity, momentum and mass transfer equations. The slip velocity condition was considered to show the reflection of gas flow in contact with the membrane surface. The solution method was based on the well-known SIMPLE algorithm and implemented using MATLAB to determine the velocity and concentration profiles. Due to change in velocity direction in the membrane module, the hybrid differencing scheme was used to solve the diffusion-convection equation. The results of the model were compared with the experimental data obtained as part of this work and good agreement was observed. The distribution of CO2 concentration inside the feed and permeate chambers was shown and the velocity profile at the membrane surface was also determined using reflection factor for polymericmembrane. The modelling result revealed that increasing the amount of CO2 in gas feed resulted in an increase in the CO2 in the permeate stream while the gas feed pressure increased. By changing the permeability, the model developed by use of the solution-diffusion concept could be used for all polymeric membranes with flat sheet modules