CO2 Storage in Low Permeable Carbonate Reservoirs: Permeability and Interfacial Tension (IFT) Changes During CO2 Injection in an Iranian Carbonate Reservoir

The lack of fundamental experimental studies on low permeable carbonate reservoirs for CO2 sequestration purposes is essential for further application of CO2 sequestration as a highly-anticipated CO2 mitigation method in deep saline aquifers, specifically those with low permeabilities. The core samples were taken from a carbonate reservoir in Iran and the brine composition was based on that of the same formation. The objective of this study is to investigate permeability alteration during CO2 sequestration in the aquifers of a low permeable Iranian carbonate reservoir. Various parameters have been investigated. The effects of different parameters such as injection pressure, confining pressure, and temperature on permeability alteration of the cores was investigated. Moreover, the interfacial tension (IFT) of CO2/brine was also determined at pressures and temperatures up to 7 MPa and 100 °C, respectively. The experimental results showed CO2 solubility and rock dissolution to be the governing mechanism when CO2 was injected into carbonate cores. The permeability measurements showed that permeability increases by increasing injection pressure and decreases by increasing confining pressure and temperature. The IFT measurement results showed that the IFT decreases significantly when there is an increase in pressure and temperature

Production of Rosuvastatin Calcium Nanoparticles Using Gas Antisolvent Technique: Experimental and Optimization

The activity of pharmaceutical substances crucially depends on the bioavailability of the substances. The bioavailability of drugs in body and their rate of dissolution in the biological fluids are increased if the particle size is decreased. In the present paper, the Gas Anti-Solvent (GAS) method was used to lower the size of rosuvastatin particles. The effects of temperature (313–338 K), pressure (105–180 bar) and initial solute concentration (20–60 mg/ml) were evaluated by Response Surface Methodology (RSM). The optimum initial solute concentration, temperature and pressure were found to be 20 mg/ml, 313 K and 180 bar, respectively which resulted in the minimum particle size. Furthermore, the particles were characterized by Differential Scanning Calorimetry (DSC), Dynamic Light Scattering (DLS), Fourier Transform Infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and X-Ray Diffraction (XRD). The analyses showed that the rosuvastatin particles (60.3 nm) precipitated by GAS process become significantly smaller than the initial particles (45.8 µm)

CO2 sequestration through direct aqueous mineral carbonation of red gypsum

The authors would like to appreciate the Department of Petroleum Engineering, Marvdasht Branch, Islamic Azad University, Marvdasht, Iran for the provision of the laboratory facilities necessary for completing this work.Peer reviewedPublisher PD

Experimental Investigation of Asphaltene Content Effect on Crude Oil/CO2 Minimum Miscibility Pressure

Minimum Miscibility Pressure (MMP) is regarded as one of the foremost parameters required to be measured in a CO2 injection process. Therefore, a reasonable approximation of the MMP can be useful for better development of injection conditions as well as planning surface facilities. In this study, the impact of asphaltene content ranging from 3.84 % to 16 % on CO2/heavy oil MMP is evaluated. In this respect, slim tube miscibility and Vanishing Interfacial Tension (VIT) tests are used. Regarding the VIT test, the Interfacial Tension (IFT) is measured by means of two methods including pendant drop and capillary apparatuses, and thereafter the MMP measurement error between slim tube and VIT methods are calculated. Based on the results, by increasing the asphaltene content, the measured MMP by slim tube method increases linearly while that by VIT follows no clear trend. The results also indicate that there is an asphaltene content range within which the MMP error between slim tube and VIT tests is minimized. IFT measurement by pendant drop and Capillary Glass Tube (CGT) methods show that by increasing asphaltene content up to 10.15 %, IFT declines, whereas for further increase in content, IFT increases because of the irregular dispersion of asphaltene in oil droplets

Thermodynamic study of (pb2+) removal by adsorption onto modified magnetic Graphene Oxide with Chitosan and Cysteine

A new modified magnetic Graphene Oxide with Chitosan and Cysteine wassynthesized for removing Pb2+ ions from aqueous solution. The properties of thisadsorbent were characterized by Field Emission Scanning Electron Microscopy (FESEM),Vibrating Sample Magnetometer (VSM) and Energy Dispersive Analysis Systemof X-ray (EDAX). Physicochemical parameters such as effect of pH, contact time,adsorbent dosage and initial concentration of Pb 2+ was also studied. The results showedthat the maximum capacity of absorbent in Lead ions adsorption (at Equilibriumconcentration of 120 ppm) occurred at pHOptimum= 5.75, tOptimum= 30 min andadsorbent 85.4 mg/g dosage=0.1 gr. Maximum empirical adsorption capacity (qmax) wascalculated 85.4 mg/g. The thermodynamic parameters (ΔHᵒ, ΔGᵒ and ΔSᵒ) showed thatthe adsorption process of Pb 2+ on modified magnetic Graphene Oxide with Chitosanand Cysteine was endothermic and spontaneous. Removal percentage was reduced to15% after five stages of Sorption/desorption studies. So, modified magnetic GrapheneOxide with Chitosan and Cysteine can be used as a complementary process for removalof Pb2+ ions from water and wastewater

Increasing Supercapacitor Features Using Reduced Graphene Oxide@Phosphorus

Supercapacitors have attracted much attention in the field of electrochemicalenergy storage. However, material preparation and stability limit their applications inmany fields. Herein, a reduced graphene oxide@phosphorus (rGO@P) electrode wasprepared using a simple inexpensive method. The new graphene structure (rGO@P) wascharacterized by X-ray diraction, Fourier transform infrared spectroscopy, scanningelectron microscopy and Energy-dispersive X-ray spectroscopy.Electrode showed excellent performances (307 F g−1), which seem to be the highestamong many other rGO@P-based electrodes reported so far. It also has an excellentcyclic stability up to 95% after 600 consecutive charge/discharge tests. So, the ease ofthe synthesis method and excellent performance of the prepared electrode materials mathave significant potential for energy storage applications

MATHEMATICAL MODELING AND SIMULATION OF SUPERCRITICAL CO2 EXTRACTION OF ZIZIPHORA TENUIOR VOLATILES

Ziziphora Tenuior is an edible medicinal plant which belongs to Labiatae family. It is often used as a treatment for some diseases such as edema, insomnia, and hypertension in Turkey, Iran and China. The main components of the Ziziphora Tenuior essential oil are p-mentha-3-en-8-ol and pulegone. In this study, the extractions of Ziziphora essential oil has been described by a two-dimensional mathematical model, and the effects of some extraction parameter variations on the extraction yield have been examined. Amongst the said parameters were fluid flow rate, extractor diameter and length and mean particle size