Jong-Soo Bae

Two-in-one fuel combining sugar cane with low rank coal and its CO₂ reduction effects in pulverized-coal power plants.

Coal-fired power plants are facing to two major independent problems, namely, the burden to reduce CO(2) emission to comply with renewable portfolio standard (RPS) and cap-and-trade system, and the need to use low-rank coal due to the instability of high-rank coal supply. To address such unresolved issues, integrated gasification combined cycle (IGCC) with carbon capture and storage (CCS) has been suggested, and low rank coal has been upgraded by high-pressure and high-temperature processes. However, IGCC incurs huge construction costs, and the coal upgrading processes require fossil-fuel-derived additives and harsh operation condition. Here, we first show a hybrid coal that can solve these two problems simultaneously while using existing power plants. Hybrid coal is defined as a two-in-one fuel combining low rank coal with a sugar cane-derived bioliquid, such as molasses and sugar cane juice, by bioliquid diffusion into coal intrapores and precarbonization of the bioliquid. Unlike the simple blend of biomass and coal showing dual combustion behavior, hybrid coal provided a single coal combustion pattern. If hybrid coal (biomass/coal ratio = 28 wt %) is used as a fuel for 500 MW power generation, the net CO(2) emission is 21.2-33.1% and 12.5-25.7% lower than those for low rank coal and designed coal, and the required coal supply can be reduced by 33% compared with low rank coal. Considering high oil prices and time required before a stable renewable energy supply can be established, hybrid coal could be recognized as an innovative low-carbon-emission energy technology that can bridge the gulf between fossil fuels and renewable energy, because various water-soluble biomass could be used as an additive for hybrid coal through proper modification of preparation conditions.

Economic evaluations of direct, indirect and hybrid coal liquefaction

The various geopolitical problems associated with oil have rekindled interest in coal, with many countries working on projects for its liquefaction. This study established the feasibility of coal liquefaction through a technical and economic examination of direct coal liquefaction (DCL), indirect coal liquefaction (ICL) and hybrid coal liquefaction (HCL) processes. An economic efficiency analysis was prepared involving costs of initial investment, annual operating and raw coal purchase and revenues from the sale of major products as key variables. For the raw materials, products and investments, analyses of net present value (NPV), internal rate of return (IRR) and sensitivity were carried out. The processes’ IRRs were found to be 22.26% (DCL), 18.43% (ICL) and 20.90% (HCL). NPVs were

Preparation of Enhanced Extraction Resin by BPO for the Separation of Rare Earth Elements (Gd, Tb, Dy, Ho)

4.720m (DCL),

Effects of Hydrothermally Pretreated Sewage Sludge on the Stability and Dispersibilty of Slurry Fuel Using Pulverized Coal

3.811 m (ICL) and

The Pore Structure Variation of Coal Char during Pyrolysis and Its Relationship with Char Combustion Reactivity

4.254 m (HCL), and payback periods were DCL 3.3 years, ICL 4.2 years, and HCL 3.6 years. As a result of the sensitivity analysis, factors greatly affecting the earning potential of coal liquefaction included product prices, raw coal prices, and construction costs, which showed similar effects in each process.

Activation of Ground Granulated Blast Furnace Slag Cement by Calcined Alunite

A resin for extraction chromatography was synthesized by suspension copolymerization, and its performance in separating four rare earth (RE) elements, gadolinium (Gd), terbium (Tb), dysprosium (Dy), and holmium (Ho) was investigated. The resin was synthesized by changing the reaction rate using a reaction initiator (benzoyl peroxide, BPO). The effects of the concentration of the eluent, HCl, were examined. The separations were best ( = 1.000, = 1.091, and = 1.495) when BPO was added in 3 aliquots, and 0.3 mol/L HCl was used as the eluent. The synthesized extraction resin gave similar separation resolutions to the commercial resin at lower HCl concentrations than the 0.6 mol/L used with the commercial resin. The scanning electron microscopy (SEM) analyses showed that the best-prepared synthesized extraction resin had uniform, spherical particles. The Fourier transform infrared (FT-IR) spectra of the synthesized extraction resins showed the characteristic signals of styrene-divinyl benzene copolymer.