In the current stage over 85% of world energy demand is supplied by fossil fuels. Coal-fired plants discharged roughly 40% of the total CO2 are the main contributors in CO2 emissions (Kim & Kim, 2004; Yang et al., 2008). Environmental issues caused by exhaust green house gases (GHG) and toxics have become global problems. Through the past studies of five decades, increased GHG levels in atmosph...

The United States currently meets 80% of its energy needs by burning fossil fuels to form CO2. The combustion-based production of CO2 has evolved into a major environmental challenge that extends beyond national borders and the issue has become as politically charged as it is technologically demanding. Whereas CO2 levels in the atmosphere had remained stable over the 10,000 years preceeding the...

Atmospheric CO2 concentrations have increased considerably since the mid-1800s and are projected to increase even further during the coming century. This rapid increase in CO2 concentration corresponds with increases in the combustion of fossil fuel, changes in agricultural land use, and deforestation since the beginning of the industrial age. These observations have prompted scientists and pol...

A bifunctionalized TiO2 film containing a dye-sensitized zone and a catalysis zone is designed for visible-light photocatalytic reduction of CO2 to chemicals continuously. Charge separation can be accomplished with electron transferring to catalysis zone and positive charge transforming to anode. Highly efficient conversion of CO2 to formic acid, formaldehyde, and methanol is achieved through t...

Sol-gel modification of mesoporous alumina membranes is a very successful technique to improve gas separation performance. Due to the formed microporous top layer, the membranes show activated transport and molecular sieve-like separation factors. This paper concentrates on the mechanism of activated transport (also often referred to as micropore diffusion or molecular sieving). Based on a theo...

Future large-scale production of H2 for use as a clean fuel will likely depend upon gasifying coal or biomass followed by steam reforming the resulting gas mixture and separating the CO2 byproduct. The process of steam reforming and CO2 separation can be greatly simplified by utilizing a new material that combines a reforming catalyst with a sorbent for CO2. Such a material was prepared in the ...

Large amounts of CH4 in the form of solid hydrates are stored on continental margins and in permafrost regions. If these CH4 hydrates could be converted into CO2 hydrates, they would serve double duty as CH4 sources and CO2 storage sites. We explore here the swapping phenomenon occurring in structure I (sI) and structure II (sII) CH4 hydrate deposits through spectroscopic analyses and its poten...

Membrane contactor using amine based absorbents is an efficient technology for CO2 separation from gaseous mixtures. A novel porous polysulfone (PSF) flat membrane was prepared via non-solvent phase inversion method. The PSF membrane was modified by adding polyvinyl pyrrolidone (PVP) to the dope solution. The fabricated membrane was used in the serpentine flow field contactor module for CO2 abs...

In this study, a time-dependent 2D axisymmetric model of a multilayer hollow fiber composite membrane for gas separation is proposed. In spite of the common multilayer membranes, which a dense layer coated on a porous support layer and subjected into the feed stream, here, the porous support is exposed to the feed gas. In this regard, the governing equations of species transport are developed f...