The physical adsorption of hydrogen sulfide and carbon dioxide gases on the zigzag (5,0) carbon nanotubes doped with nitrogen was investigated through the application of B3LYP/6-31G* at the level of theory on Gaussian 03 software. A variety of stable and high abundance structures of nitrogen doped carbon nanotubes were considered in order to study the interaction between the mentioned gases in ...

Graphene-based materials have aroused enormous focus on a wide range of engineering fields because of their unique structure. One of the most promising applications is gas adsorption and sensing. In electrical engineering, graphene-based sensors are also employed as detecting devices to estimate the operation status of gas insulated switchgear (GIS). This paper reviews the main synthesis method...

The physical adsorption of hydrogen sulfide and carbon dioxide gases on the zigzag (5,0) carbon nanotubes doped with nitrogen was investigated through the application of B3LYP/6-31G* at the level of theory on Gaussian 03 software. A variety of stable and high abundance structures of nitrogen doped carbon nanotubes were considered in order to study the interaction between the mentioned gases in ...

As an illustration, consider the following two-step adsorption cycle to purify helium diving gas. Helium diving gas is principally a mixture of oxygen and helium, when the diving chambers are depressurised, the contaminated gas will consist mainly of carbon dioxide, oxygen and helium. Traditionally this waste gas has been thrown away. The PSA cycle described below is a method of purifying this ...

A theoretical model is established to describe the response mechanism of surface acoustic wave (SAW) gas sensors based on physical adsorption on the detector surface. Wohljent's method is utilized to describe the relationship of sensor output (frequency shift of SAW oscillator) and the mass loaded on the detector surface. The Brunauer-Emmett-Teller (BET) formula and its improved form are introd...

Effect of fractional gas hold-up εG on volumetric mass transfer coefficient KLa were studied for two different type of airlift contactors conventional and modified. KLa was directly proportional to gas hold-up within bubbly flow regime (UG < 0.075 m/s ) in conventional one but reverse trend ( inversely proportional) was reported in modified airlift contactor. Mathematical relation between KLa a...

One of the major challenges in petroleum industry is producing residual oil from underground. One of the major techniques for enhancing oil recovery (EOR) is using gas injection. However, gas has poor volumetric sweep efficiency, this is attributed to its high mobility which considers to be higher compared with oil and water mobility. Several techniques are proposed and applied for reducing gas...

Two-dimensional (2D) molybdenum disulfide (MoS2) has been attracting rapidly increasing interest for application in chemoresistive gas sensors owing to its moderate band gap energy and high specific surface area. However, the mechanism of chemoresistive sensing via the adsorption and desorption of gas molecules and the influence of the shape of 2D materials are not well understood yet. Herein w...

Reducing CO2 in the atmosphere and preventing its release from point-source emitters, such as coal and natural gas-fired power plants, is a global challenge measured in gigatons. Capturing CO2 at this scale will require a portfolio of gas-separation technologies to be applied over a range of applications in which the gas mixtures and operating conditions will vary. Chemical scrubbing using abso...

the volumetric changes in the coal matrix (coal shrinkage), permeability under various gas environment conditions as well as perographical properties were studied in the laboratory. the shrinkage and permeability of coal were examined with respect to changing gas type and confining pressures. the shrinkage tests were carried out in high-pressure bombs while the permeability study was conducted ...