Processing of Iridium Doped Materials and Experimental Investigation of Their Hydrogen Adsorption Capacity

2018 ◽  
Vol 69 (6) ◽  
pp. 1468-1472
Author(s):  
Radu Mirea ◽  
Mihai Iordoc ◽  
Gabriela Oprina ◽  
Gimi Rimbu

The paper aims to present the investigation of H2 adsorption capacity in metal doped nanostructured materials, by using two methods. Carbonic materials are considered to be one of the most promising materials to be used for hydrogen adsorption and storage. They have different applications and one of the most important is considered to be fuel cells technology. By using metals for doping these materials, the adsorption capacity increases, thus approaching the target of 6.5% weight ratio of H2 adsorbed in a substrate. Within these investigations multi-wall nanotubes and poly-aniline have been used as substrates. The poly-aniline has been prepared and doped in laboratory while the nanotubes used in experiments have been purchased from the market and afterwards doped in laboratory. The doping procedure consists of a physical-chemical method which involves salts of the metal for doping and the use of ultrasounds in order to activate the substrate for doping. The adsorption capacity of the carbonic materials has been determined by using spill over phenomena in a PCT Pro-User apparatus, provided by SETARAM and also by cyclic voltametry, by using VoltaLab-40 apparatus. In order to investigate the adsorption capacity of the nanostructured carbonic materials, the experiments have been carried out at different pressures. Both substrates have been characterized in order to determine their porosity, BET surface and structure. The collected data have been processed by using the PCT Pro-User apparatus�s software. The results have been compared with the available data from literature and a good consistency was found.

2019 ◽  
Vol 70 (9) ◽  
pp. 3123-3128
Author(s):  
Radu Mirea ◽  
Mihai Iordoc ◽  
Gimi Rimbu

A comparative research related to hydrogen adsorption capacity of multiwall nanotubes (MWNTs) doped with Platinum (Pt), Ruthenium (Ru) and Iridium (Ir) was carried out. Carbonic materials are considered to be one of the most promising materials for hydrogen adsorption and storage;they have different applications and fuel cells technology may be considered the most important of them. By using transitional metals for doping carbonic materials, the adsorption capacity increases, can approach the target of 6.5% weight ratio of H2 adsorbed in a substrate. The doping procedure consists in a physical or chemical method which involves metal for doping of a nano carbon structure. The use of ultrasounds is known in order to activate the substrate by inducing fractures within its internal structure. The adsorption capacity of the carbonic materials, which is a consequence of spill over phenomena, has been determined both by physical adsorption and by cyclic voltammetry. The substrates have been characterized in order to determine their BET and microspores surface and structure. The collected data related to the adsorption capacity have been processed by using a dedicated software. The results have been compared with the available data from literature and a good consistency was found.


2020 ◽  
Vol 5 (3) ◽  
pp. 221
Author(s):  
Muhammad Azam ◽  
Muhammad Anas ◽  
Erniwati Erniwati

This study aims to determine the effect of variation of activation temperature of activated carbon from sugar palm bunches of chemically activatied with the activation agent of potassium silicate (K2SiO3) on the adsorption capacity of iodine and methylene blue. Activated carbon from bunches of sugar palmacquired in four steps: preparationsteps, carbonizationstepsusing the pyrolysis reactor with temperature of 300 oC - 400 oC for 8 hours and chemical activation using of potassium silicate (K2SiO3) activator in weight ratio of 2: 1 and physical activation using the electric furnace for 30 minutes with temperature variation of600 oC, 650 oC, 700 oC, 750 oC and 800 oC. The iodine and methyleneblue adsorption testedby Titrimetric method and Spectrophotometry methodrespectively. The results of the adsorption of iodine and methylene blue activated carbon from sugar palm bunches increased from 240.55 mg/g and 63.14 mg/g at a temperature of 600 oC to achieve the highest adsorption capacity of 325.80 mg/g and 73.59 mg/g at temperature of 700 oC and decreased by 257.54 mg/g and 52.03 mg/g at a temperature of 800 oCrespectively.However, it does not meet to Indonesia standard (Standard Nasional Indonesia/SNI), which is 750 mg/g and 120 mg/g respectively.


Proceedings ◽  
2021 ◽  
Vol 52 (1) ◽  
pp. 2
Author(s):  
Noé Anes García ◽  
Antonio Luis Marqués Sierra

In recent years, developments made to reduce the consequences generated using petroleum products have been strengthening; therefore, biofuels have become a requirement in different countries worldwide with the objective of reducing not only the high levels of current pollution, but also mitigating the effects generated by global warming. Despite the advances that have been made in the field of research on Jatropha, it is still necessary to carry out more detailed studies aimed at achieving a better use of it, identifying the influence of its physical–chemical properties in terms of quality levels, as well as determining its behavior when mixed with palm oil to achieve a biodiesel with better yields, whose impact will be reflected mainly in the environmental field, helping to mitigate the production of greenhouse gases that are produced by petroleum products. Although currently the biofuels sector has made important advances in research, it is necessary to deepen the physical–chemical analyses both in the production and storage processes of biodiesel, so that in the future it can be fully fulfilled with the energy requirements that are currently only achieved with fossil fuels, so it is necessary to direct this research toward the development of new products with improved characteristics, especially when exposed to prolonged storage times and low temperatures.


2010 ◽  
Vol 133 (15) ◽  
pp. 154706 ◽  
Author(s):  
Miao Miao Wu ◽  
Qian Wang ◽  
Qiang Sun ◽  
Puru Jena ◽  
Yoshiyuki Kawazoe

CrystEngComm ◽  
2013 ◽  
Vol 15 (45) ◽  
pp. 9348 ◽  
Author(s):  
Zhiyong Lu ◽  
Liting Du ◽  
Baishu Zheng ◽  
Junfeng Bai ◽  
Mingxing Zhang ◽  
...  

SPE Journal ◽  
2021 ◽  
pp. 1-26
Author(s):  
Zizhong Liu ◽  
Hamid Emami-Meybodi

Summary The complex pore structure and storage mechanism of organic-rich ultratight reservoirs make the hydrocarbon transport within these reservoirs complicated and significantly different from conventional oil and gas reservoirs. A substantial fraction of pore volume in the ultratight matrix consists of nanopores in which the notion of viscous flow may become irrelevant. Instead, multiple transport and storage mechanisms should be considered to model fluid transport within the shale matrix, including molecular diffusion, Knudsen diffusion, surface diffusion, and sorption. This paper presents a diffusion-based semianalytical model for a single-component gas transport within an infinite-actingorganic-rich ultratight matrix. The model treats free and sorbed gas as two phases coexisting in nanopores. The overall mass conservation equation for both phases is transformed into one governing equation solely on the basis of the concentration (density) of the free phase. As a result, the partial differential equation (PDE) governing the overall mass transport carries two newly defined nonlinear terms; namely, effective diffusion coefficient, De, and capacity factor, Φ. The De term accounts for the molecular, Knudsen, and surface diffusion coefficients, and the Φ term considers the mass exchange between free and sorbed phases under sorption equilibrium condition. Furthermore, the ratio of De/Φ is recognized as an apparent diffusion coefficient Da, which is a function of free phase concentration. The nonlinear PDE is solved by applying a piecewise-constant-coefficient technique that divides the domain under consideration into an arbitrary number of subdomains. Each subdomain is assigned with a constant Da. The diffusion-based model is validated against numerical simulation. The model is then used to investigate the impact of surface and Knudsen diffusion coefficients, porosity, and adsorption capacity on gas transport within the ultratight formation. Further, the model is used to study gas transport and production from the Barnett, Marcellus, and New Albany shales. The results show that surface diffusion significantly contributes to gas production in shales with large values of surface diffusion coefficient and adsorption capacity and small values of Knudsen diffusion coefficient and total porosity. Thus, neglecting surface diffusion in organic-rich shales may result in the underestimation of gas production.


Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2237
Author(s):  
Sara Stelitano ◽  
Giuseppe Conte ◽  
Alfonso Policicchio ◽  
Alfredo Aloise ◽  
Giovanni Desiderio ◽  
...  

Pinecones, a common biomass waste, has an interesting composition in terms of cellulose and lignine content that makes them excellent precursors in various activated carbon production processes. The synthesized, nanostructured, activated carbon materials show textural properties, a high specific surface area, and a large volume of micropores, which are all features that make them suitable for various applications ranging from the purification of water to energy storage. Amongst them, a very interesting application is hydrogen storage. For this purpose, activated carbon from pinecones were prepared using chemical activation with different KOH/precursor ratios, and their hydrogen adsorption capacity was evaluated at liquid nitrogen temperatures (77 K) at pressures of up to 80 bar using a Sievert’s type volumetric apparatus. Regarding the comprehensive characterization of the samples’ textural properties, the measurement of the surface area was carried out using the Brunauer–Emmett–Teller method, the chemical composition was investigated using wavelength-dispersive spectrometry, and the topography and long-range order was estimated using scanning electron microscopy and X-ray diffraction, respectively. The hydrogen adsorption properties of the activated carbon samples were measured and then fitted using the Langmuir/ Töth isotherm model to estimate the adsorption capacity at higher pressures. The results showed that chemical activation induced the formation of an optimal pore size distribution for hydrogen adsorption centered at about 0.5 nm and the proportion of micropore volume was higher than 50%, which resulted in an adsorption capacity of 5.5 wt% at 77 K and 80 bar; this was an increase of as much as 150% relative to the one predicted by the Chahine rule.


Sign in / Sign up

Export Citation Format

Share Document