Rapid and high-capacity MgO composites by salt-controllable precipitation for pre- combustion CO2 capture

Pre-combustion CO2 capture at intermediate temperatures can allow for more flexibility to control over CO2 emission in various industrial processes. For example, the pre-combustion capture can be applied for an Integrated Gasification Combined Cycle (IGCC) due to the use of relatively mild operating temperatures and accessible heat sources. Efficient materials for CO2 capture and H2 production in water gas shift reactor can contribute to improving the overall reliability and efficiency in IGCC process. As a first step, we presented triple salt-promoted MgO composites (NaNaLi salts) by a precipitation method to enhance sorption capacity, rate, and stability. In the conventional precipitation method, a filtration step makes control and reproductivity of the salt composition difficult owing to the unknown residual salts. In this study, we developed a synthesis procedure of precipitation method to control the composition of salts as well as improve physical properties. As-prepared MgO exhibited excellent sorption capacities of 73.0 wt.% at 325 °C in pure CO2 and high sorption rate within 10 min. Stability of composites were evaluated under various gas and time condition and were superior to those of the other MgO-based sorbents reported. With a wet gas mixture (29% CO2, 3% H2O, and balance N2) for sorption and CO2 regeneration, the working capacity stabilized after 20 cycles at 23 and 4.6 wt% for 60/15 min and 10/5 min cycles, respectively. The enhancement and reduction of working capacity along cycles were explained based on liquid phase sintering, i.e., rearrangement, solid-reprecipitation, and densification. However, too long sorption time in the capacity evaluation is not practical because a fixed bed or fluidized bed has a difficulty of temperature control and a large bed size to control high volumes of gases. Therefore, further development is required for an advanced sorbent with high sorption rate and capacity in practical utilization. Therefore, as a second step, a facile method for sorbent with rapid and high-capacity CO2 capture was developed by incorporating additional metal ioninto salt-promoted MgO sorbents using a coprecipitation. At the same fast cycle (10min/5min), the cyclic sorption capacity of 12 wt.% was observed from the developed MgO composite by using wet mixture sorption (29 vol.% CO2, vol.% H2O and N2 balance) and CO2 regeneration. Please click Additional Files below to see the full abstract

H2 pressure swing adsorption for IGCC power plant and techno-economic analysis of integrating PSA to IGCC with carbon capture

Carbon capture and sequestration technologies emerge as the effectual remediation processes to reduce CO2 emissions from coal power plants. Integrated gasification combined cycle (IGCC) is a representative technology for utilizing coal as feedstock and is consequently playing a more important role to cover the global energy demand. The IGCC produces H2-rich mixture at high pressures (30-35 bar) after capturing CO2. It is reported that the high purity H2 recovered from the IGCC process can be economically supplied to a hydrogen turbine or fuel cell. And a PSA process is a strong candidate to produce high purity H2 from the IGCC effluent gas. However, due to higher operating pressure than the present H2 PSA processes, reducing the operating costs and efficiency has emerged as one of the key issues. Please click Additional Files below to see the full abstract

Angelicae Dahuricae Radix Inhibits Dust Mite Extract-Induced Atopic Dermatitis-Like Skin Lesions in NC/Nga Mice

We examined whether Angelicae Dahuricae Radix (AR) suppresses the development of atopic dermatitis (AD)-like skin lesions induced by Dermatophagoides farinae in NC/Nga mice. To investigate the effect of AR, we measured the AD severity score, measured plasma levels of IgE and histamine, and performed histological analysis in NC/Nga mice. We also confirmed the anti-inflammatory effects of AR by measuring TARC/CCL17 production from LPS-treated RAW 264.7 cells and mRNA levels of TARC and MDC/CCL22 in TNF-α/IFN-γ-treated HaCaT cells. 10 mg/day of AR extract was applied for 4 weeks to NC/Nga mice. Both the AR extract and 0.1% tacrolimus suppressed the development of AD-like skin lesions and reduced dermatitis scores of the back and ear skin. AR extracts caused an inhibition of histological changes induced by repeated application of D. farinae and a reduction of IgE and histamine levels in plasma (P < 0.05). Furthermore, NO production in LPS-treated RAW 264.7 cells was diminished in a dose-dependent manner, and hTARC production and TARC and MDC mRNA levels in TNF-α/IFN-γ-treated HaCaT cells were diminished by AR. The inhibitory effect of AR on NO, TARC and MDC production may be associated with the suppression of AD-like skin lesions in D. farinae-induced NC/Nga mice

Improvement of Mechanical Properties of UV-curable Resin for High-aspect Ratio Microstructures Fabricated in Microstereolithography

Recently, microstructures fabricated using microstereolithography technology have been used in the biological, medical and mechanical fields. Microstereolithography can fabricate real 3D microstructures with fine features, although there is presently a limited number of materials available for use in the process. Deformation of the fine features on a fabricated microstructure remains a critical issue for successful part fabrication, and part deformation can occur during rinsing or during fabrication as a result of fluid flow forces that occur during movement of mechanical parts of the system. Deformation can result in failure to fabricate a particular feature by breaking the feature completely, spatial deflection of the feature, or attaching the feature to neighboring microstructures. To improve mechanical strength of fabricated microstructures, a clay nanocomposite can be used. In particular, a high-aspect ratio microstructure can be fabricated without distortion using photocurable liquid resin containing a clay nanocomposite. In this paper, a clay nanocomposite was blended with a photocurable liquid resin to solve the deformation problem that occurs during fabrication and rinsing. An optimal mixture ratio of a clay nanocomposite was found through tensile testing and the minimal allowable distance between microstructures was found through fabrication experimentation. Finally, using these results, high-aspect ratio microstructures were fabricated using a clay nanocomposite resin without distortion