Energy Technologies and CO2 Management Symposium: Session III
Sponsored by: TMS Extraction and Processing Division, TMS: Energy Committee
Program Organizers: Xiaobo Chen, RMIT University; Yu Lin Zhong, Griffith University; Lei Zhang, University of Alaska Fairbanks; John Howarter, Purdue University; Alafara Baba, University of Ilorin; Neale Neelameggham, IND LLC; Cong Wang, Northeastern University; Ziqi Sun, Queensland University of Technology
Tuesday 8:30 AM
February 25, 2020
Room: 17A
Location: San Diego Convention Ctr
Session Chair: Cong Wang, Northeastern University; Lihong Su, University Of Wollongong
8:30 AM Keynote
An Overall Assessment of Welding Fluxes Geared Towards High Heat Input Applications: Cong Wang1; Imants Kaldre2; 1Northeastern University; 2University of Latvia
In recent years, to further improve welding efficiency, SAW with higher heat input has been widely applied. SAW relies on appropriate fluxes to obtain satisfactory weld metal properties. Generally, flux is employed in SAW to stabilize the arc, add alloying elements, and refine WM microstructure. To better control WM composition and offer acceptable mechanical properties, an understanding of element transfer mechanisms between slag and weld pool during welding is necessitated. A series of fused CaF2 based fluxes have been developed to investigate element transfer behaviors under high heat input submerged arc welding. Effects of respective constituent on the transfer of Si, Mn, and O have been thoroughly evaluated. Thermodynamic considerations have been attempted for constraining chemical reactions and mechanisms involved in welding. The transfer of Si and Mn is primarily governed by the slag-metal reactions in the namely ‘hot’ zone while the transfer of O is generally controlled by the chemical reactions in both ‘droplet’ zone and ‘hot’ zone. Our work may provide criteria on the design of CaF2-based fluxes under high heat input.
9:00 AM Invited
Achieving Controlled Surface Roughness of Ultra-thin Al Foils as Current Collector: Lihong Su1; 1University of Wollongong
Al foils with thicknesses of a few microns are usually used as the current collector in the cathode electrode in lithium-ion batteries. In this research, ultra-thin Al foils with thicknesses down to ~ 1 micron were prepared using clad rolling method by placing Al foil in the core. The surface roughness of the foils was in the range of 0.1 to 0.5 microns and was achieved by using different clad materials. The adhesion ability of the Al foils were examined by interfacial shear tests of graphite coated foils and the results showed that the foils with larger roughness resulted in higher shear stress. Charge/discharge cyclic tests were used for investigating the properties of the Al foils as current collectors and the results showed that the capacity stability of the Al foils with larger surface roughness is better than the ones with smaller surface roughness.
9:25 AM
Photocatalytic Hydrogenolysis to Convert Lignin-derivatives to Phenol Under Ambient Conditions: Yun-Chung Shen1; Jeffrey Wu2; 1Institute of Nuclear Energy Research; 2National Taiwan University
In recent years, excessive CO2 produced from the fossil fuels leads to climate change. Therefore, the technology development of renewable energy is important. Lignin is the second abundant biomass form on earth behind cellulose. Lignin is the most promising nature resource for producing aromatic compounds attributed to the large group aromatic structure.This research attempted to simulate the bond dissociation status in lignin by using model compound, benzyl phenyl ether (BPE) under ambient pressure. The BPE represented one of the major type of ether linkages, α-O-4 linkage. The BPE can be dissociated by photocatalytic hydrogenolysis reactions. The hydrogenolysis of BPE was carried out using 1 wt%Pd/TiO2 photocatalyst under UV-light irradiation at ambient temperature. The BPE conversion can reach above 95% in 3 hours and the maximum phenol yield is near 60%. Our study showed that photo hydrogenolysis by photocatalyst is a promising method to convert biomass into valuable products.
9:45 AM
Molecular Dynamics Simulation of CO2 Absorption Behavior in Hydrotalcite and its Derived Oxides: Hao Zhang1; 1University of Alberta
Hydrotalcite (or LDHs) derived materials are considered to be promising candidates for solid sorbents for CO2 capture at intermediate temperatures. Using molecular dynamics (MD) simulation, we investigated the atomistic structures of monocarboxylic acid intercalated LDHs. The replacement of carbonate anions by stearate anions and the presence of water molecules could greatly increase the basal spacing. Further, we investigated CO2 adsorption behavior on amorphous layered double oxides (LDOs) derived from LDHs at elevated temperatures. The MD simulation of structure evolution upon heating agreed well with experimental results. The simulation results also showed that CO2 dynamic residence time on LDOs was sensitive to the Mg/Al ratio and the average amount of residence time of CO2 on surface of LDOs reached maximum when the Mg/Al ratio was 3. Examination of the binding between CO2 and mixed oxides revealed that both magnesium and oxygen in amorphous LDOs contributed to CO2 adsorption.
10:05 AM Break
10:25 AM
Improved Physical Solvents for Pre-combustion CO2 Capture: Jeffrey Culp1; Robert Thompson1; Wei Shi1; Surya Tiwari1; Kevin Resnik1; Nicholas Siefert2; David Hopkinson2; 1National Energy Technology Laboratory / LRST; 2National Energy Technology Laboratory
A continuously looping solvent-based process using reversible physical interactions is favored for pre-combustion capture of CO2 from Integrated Gasification Combined Cycle (IGCC) power plants due to favorable partial pressures (20-30bar) of CO2 in the gas stream. Current state-of-the-art CO2 solvents such as Selexol™ often suffer from significant water affinity which results in the removal of large volumes of water from the pre-combustion fuel gas stream. This adsorbed water is needed as an energy-generation source in the combustion turbine. In addition, removal of adsorbed water results in an added energy penalty during the solvent regeneration step. We present here improved hydrophobic CO2 solvents which maintain a high CO2 adsorption affinity while minimizing the co-adsorption of H2O and H2. They are low viscosity, low cost, and environmentally friendly with high boiling points suitable for reactor operations at temperatures near 40°C.
10:45 AM
Hydrogen as a Fuel and Ramifications: Ashok Khandkar1; Neale Neelameggham2; 1University of Utah; 2IND LLC
There are expectations that hydrogen when produced economically will act as a clean fuel. This paper analyzes the ramifications on this perception. Thermo-chemical computations are made to show what may happen during combustion of hydrogen and associated reactions in this analysis.
11:05 AM Cancelled
Theoretical and Experimental Research on the Mass Changes of Elements in Molten Steel with CO2 Used as RH Lifting Gas: Baochen Han1; Rong Zhu1; Guangsheng Wei1; Chao Feng1; Jianfeng Dong1; 1University of Science and Technology, Beijing
CO2 injection into RH as lifting gas was recently proposed instead of Ar. In this study, FactSage software was used for calculating the mass changes of elements in thermodynamic equilibrium with CO2 injection under vacuum condition. Compared with Ar, CO2 as RH lifting gas can be used for a small amount of decarburization without a significant increase in oxygen content of molten steel. And the carbon content of alloys can be theoretically increased by more than 12 % if all CO2 participates in the reaction between CO2 and [C]. Furthermore, the industrial application research of CO2 injection into RH as lifting gas was carried out in a commercial 150t RH. The results agreed with the above theoretical trends. And the problem of aluminum loss can be solved by reducing the additive amount of aluminum alloy in the ladle furnace (LF) and replenishing the aluminum during the RH refining later stage.