Jinsoo Kim

In-situ mineralization of carbon dioxide in a coal-fired power plant

ABSTRACT Mitigation of anthropogenic carbon dioxide is needed in order to allow societies to maintain the existing carbon-based infrastructure, while minimizing the effects of carbon dioxide (CO2) on the earth eco-system. A system that consists of pressure swing adsorption and in-situ mineralization unit was introduced to capture carbon dioxide (CO2) from a 700 MW pulverized coal-fired power plant. Results from the work demonstrate that pressure swing adsorption for post-combustion carbon capture consumed the least energy, followed by biomass co-firing, pre-combustion cryogenic-membrane hybrid, and post-combustion monoethanolamine absorption. For carbon capture and sequestration, the pressure swing adsorption-fixation system was found to yield the lowest environmental burden factor, followed by off-site sequestration in deep sea and depleted underground oil/gas fields.

Highly Perm-Selective Micro-Porous Hydrotalcite-Silica Membrane for Improved Carbon Dioxide-Methane Separation

A notable improvement of carbon dioxide (CO2) adsorption in meso- and micro-porous membranes was observed when hydrotalcite (HT) was incorporated in the membranes. For carbon dioxide in carbon dioxide-methane (CH4) mixture, HT-silica membrane successfully overcame the upper permeability/selectivity limitation for glassy and polymeric membranes, despite the absence of a solution-diffusion mechanism that is typically present in the glassy and polymeric membranes. The performance of HT-silica membrane was observed to exceed that of micro-porous silica and high performance zeolitic imidazolate framework (ZIF) membranes. Incorporating unnecessarily high HT content in silica membrane, however, caused the membrane to lose its molecular sieving capacity and resulted in reduced selectivity of the gas.

Gasification Characteristics of Pinus rigida (Pitch Pine) and Quercus variabilis (Oriental Oak) with Dolomite Catalyst in a Fluidized Bed Reactor

In this study, coniferous (pitch pine, Pinus rigida) and broad-leaved (Oriental oak, Quercus variabilis) trees were gasified in a bubbling fluidized bed reactor, and the effects of reaction temperature and catalyst species on product yields and selectivities were systematically investigated. Upon increasing the gasification temperature from 800 to 900°C, the gas yield of P. rigida maintained similar values at 75.15–78.41%, while the gas yield of Q. variabilis decreased from 71.05 to 58.15% and the char and oil yields increased. The composition of gaseous products was affected according to catalyst species. When dolomite-based catalysts were used for fog biomass gasification, the hydrogen fraction increased substantially, while the carbon monoxide fraction decreased.

Fast Pyrolysis of Spent Coffee Waste and Oak Wood Chips in a Micro-tubular Reactor

Fast pyrolysis of spent coffee waste, a major non-cellulosic material, and oak wood chips, a cellulosic material, was carried out in a micro tubular reactor over a temperature range of 550 to 750°C with sweep gas flow rates of 20 and 500 mL/min. When the temperature was raised from 550 to 750°C, the gas yields were significantly enhanced, but the liquid yields were reduced. The highest liquid yield, 63.4 wt%, was obtained after pyrolysis of spent coffee waste at 550°C at a sweep gas rate of 500 mL/min. The highest gas yield, 65.74 wt%, was obtained after pyrolysis of the oak wood chips at 750°C at a sweep gas flow rate of 20 mL/min. The gas products primarily included considerable amounts of CO, CO2, and hydrocarbon-rich gases but no hydrogen. Furthermore, regardless of the biomass source, the hydrocarbon-rich gases were qualitatively similar and largely consisted of methane, ethane, ethylene, propane, and propylene. The gas chromatography-mass spectrometry analysis of the pyrolyzed bio-oils demonstrated that the major compounds were phenol derivatives, aldehydes, ketones, acids, and alcohols.