Pan American Materials Congress: Materials for Green Energy: Environmental Assessment of Green Energy
Sponsored by: Third Pan American Materials Congress Organizing Committee
Program Organizers: Ramalinga Viswanathan Mangalaraja, University of Concepcion; Hector Calderon, ESFM-IPN; Julie Schoenung, University of California, Irvine; Roberto Arce, SAM - Soc. Argentina de Materiales

Tuesday 3:40 PM
February 28, 2017
Room: Marina G
Location: Marriott Marquis Hotel

Session Chair: Julie Schoenung, University of California, Irvine

3:40 PM  
A Comparison between Recycled Spent Zeolite and Calcite Limestone for Manganese Removal: Adarlene Silva1; Rodrigo Figueiredo1; Versiane Leao1; 1Universidade Federal de Ouro Preto
    The current work initially investigated the manganese removal by sorption in a recycled spent zeolite (faujasite) used in the oil industry. Equilibrium adsorption was described by the Langmuir isotherm (r2>0.99) with a maximum loading of 10.9mg/g-zeolite. The performance of the spent zeolite was compared with that of limestone (a low cost sorbent). In this latter case, equilibrium sorption was also modelled using the Langmuir isotherms with 1.03mg/g-limestone as maximum uptake. Fixed-bed sorption on both materials was also studied and solid loadings increased with the aqueous metal concentration. The Thomas model was selected to describe the breakthrough curves and showed good correlation with the experimental data for both samples and indicated a maximum solid uptake of 0.33mg/g-solid in faujasite and 0.03mg/g in limestone. Vale and funding agencies FINEP, CAPES, CNPQ, FAPEMIG are acknowledged.

4:00 PM  
Environmental Impact of the Synthesis of Calcium Silicates (C2S AND C3S) by Combustion Processes: Juan Restrepo1; Oscar Restrepo1; Jorge Tobón1; 1Universidad Nacional de Colombia
    Portland cement is obtained by a conventional synthesis process from a mixture of limestone and clay at high temperature (1450 °C). This work presents the fabrication process of pure calcium silicate phases like belite (C2S) and alite (C3S) by alternative synthesis methods, like Solution Combustion Synthesis (SCS), and the consequences in the mitigation of CO2 emissions and the energy consumption. The use of fossil fuels is the main factor in the environmental impact of the cement industry. When analyzing the emissions in the production of pure phases C3S emits 0.58 tons of CO2 per ton of cementitious materials produced and C2S emits 0.51. Additionally, to produce 1 ton of clinker consumes approximately 5.86 GJ per ton of clinker produced by wet process and 3.35 GJ per ton of clinker produced by dry process. These methods use different paths from those of solid-state processes allowing an important environmental mitigation.

4:20 PM  
Environmentally Responsible Polymer Selection for Organic Photovoltaic Solar Cells: Haoyang He1; Yadira Gutierrez2; Thomas Young2; Julie Schoenung1; 1University of California Irvine; 2University of California, Davis
    As the development of organic photovoltaic (OPV) solar cells is expanding, a variety of low band gap polymers (LBGPs) continue to be explored in efforts to improve device efficiency. These polymers, however, require a diverse range of process chemicals for fabrication. In an effort to provide guidance on environmentally responsible polymer selection, chemical hazard assessment was conducted to investigate the toxicity of the associated process chemicals. Specifically, we used the GreenScreen for Safer Chemicals TM framework to evaluate the process chemicals used to make thirteen different LBGPs through select laboratory scale processes. More than 140 distinct chemicals were evaluated. By using GreenScreen, several databases were examined, and the results demonstrate that most of the chemicals are chemicals of high concern due to priority human health toxicities and/or other hazards. The role of data gaps in creating uncertainty and the inability to evaluate some of the chemicals was also investigated.

4:40 PM  
Electromagnetic Levitation Refining Of Silicon-iron Alloys for Generation of Solar Grade Silicon: Yindong Yang1; Katherine Le1; Mansoor Barati1; Alex McLean1; 1University of Toronto
    At present, expensive semiconductor grade silicon (SEG-Si) is used for the manufacture of cells to convert solar energy into electricity. This results in a high cost for photovoltaic electricity compared to electricity derived from conventional sources. The processing of inexpensive metallurgical silicon, or ferrosilicon alloys to solar grade silicon, is a potentially economical refining route to produce photovoltaic (PV) silicon. With phosphorus being one of the most difficult impurities to remove by conventional techniques, this project investigated the use of electromagnetic levitation (EML) of ferrosilicon (75Fe-25Si) in a hydrogen-argon gas stream (48.5% H2), to assist with dephosphorization. The experimental results demonstrated that dephosphorization was achieved through increased processing time in the EML system, with approximately 40% of phosphorus removed from ferrosilicon after 20 minutes. Effects of changing system pressure, thermodynamic and kinetic factors on dephosphorization were also evaluated.

5:00 PM  
Novel Metrics for Assessing Criticality of Byproduct Metals: Gabrielle Gaustad1; Michele Bustamante2; Berlyn Hubler1; Callie Babbitt1; Alexandra Leader1; 1Rochester Institute of Technology; 2MIT
    Critical and strategic materials are characterized by their importance in key applications and their vulnerability to supply chain disruptions. Much current research focuses on identifying and quantifying metrics and indicators that can predict potential supply chain risks for these materials. Most current methods to evaluate the criticality or scarcity of materials are static and narrowly focused on the physical reserves of one material. This is problematic for many clean energy materials that are byproducts of production of other material systems. This work uses a systems framework to define novel metrics for criticality combining aspects of life-cycle assessment, ecology, commodity economics, and techno-economic modeling. Results show that such metrics are in stark contrast to many widely used metrics and can provide better context for understanding potential for supply disruption in parent-daughter metal systems.

5:20 PM  
Technical and Environmental Assessment of an Alternative Binder for Low Traffic Roads with LCA Methodology: Alejandra Balaguera Quintero1; Diana Gómez Cano1; Gloria Carvajal Peláez1; Yhan Arias2; 1Universidad de Medellín; 2Universidad Nacional de Colombia
    Currently, low traffic roads in most countries are made up of unpaved roads; therefore, to increase the bearing capacity and durability of soils, using stabilizers such as lime and portland cement is required. In this paper, the results obtained from the addition of alternative binder materials based on industrial byproducts such as alkali activated coal ashes that work as soil stabilizers with sustainability criteria and are assessed through Life Cycle Assessment (LCA); this process is approached from the preparation, packaging and storage of binder material, its activation and finally the application in test sections obtaining unconfined compressive strengths of the order of 2 MPa; which represented an increase in resistance above 300% for the same soil without stabilization.