Fenton reaction has been focused as an option of CO2 reduction to organic compounds such as alcohol. We investigated the effect of morphology of precipitates during Fenton reaction to CO2 reduction in order to establish effective and validated process. Precipitates during/after reactions were analyzed by X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR). Morphology of precipitates was gradually changed from ferrihydrite to schwertmannite when the reaction time and pH were increased. The chemical thermodynamics equilibrium calculation suggested that schwertmannite was the main precipitate in Fenton reaction. In the actual experiments, ferrihydrite was also formed because schwertmannite is hardly precipitated under pH sharp fluctuation associated with Fenton reaction. Reactivity between hydrogen peroxide and artificial sludge (ferrihydrite or schwertmannite) was measured by Absorptiometer using the Mutarotase-GOD method. Ferrihydrite consumed more hydrogen peroxide than schwertmannite, which suggested that hydroxyl radical was produced by the reaction between hydrogen peroxide and the surface of ferrihydrite. All experimental results showed that more CO2 was reduced to organic compounds when more ferrihydrite was formed in precipitates. These results suggested that ferrihydrite was more largely contributed to Fenton reaction than schwertmannite.
This paper overviews policy and regulatory developments of the countries that introduce comprehensive framework for enabling commercially viable CCS projects. In the analysis, CCS related laws are categorized by their roles into, those oblige or urge operators to take emission reduction measures, those permit operators to implement CCS activities and those support demonstration projects with a goal of CCS commercialization. Governments with a progressive vision are found to have developed legal systems consisting of all three categories of laws.
Capillary trapping is one of the major mechanisms to hold CO2 in reservoirs against buoyancy force. In present paper, the effect of porous structures on the residual gas saturation was investigated numerically by means of lattice Boltzmann method (LBM). Numerical simulations were carried out for twelve artificially-generated porous media. Water was injected into the porous media filled with supercritical CO2 at constant pressure difference until the residual gas trapping condition. The residual gas saturation increases with a decrease in the porosity and the average pore throat radius. At the relatively high capillary number of 10-4, lower pore throat radii with higher capillary pressure tend to hold CO2 bubbles against the pressure gradient. Under the hydrophilic conditions, the residual gas saturation decreases monotonically with an increase in the contact angle. However, the positions and sizes of trapped gas bubbles change absolutely with the contact angle.