Energy Technologies: Heat Recovery
Sponsored by: TMS Extraction and Processing Division, TMS Light Metals Division, TMS: Energy Committee, TMS: Pyrometallurgy Committee
Program Organizers: Lei Zhang, University of Alaska Fairbanks ; Jaroslaw Drelich, Michigan Technological University; Neale Neelameggham, Ind LLC; Donna Guillen, Idaho National Laboratory; Nawshad Haque, CSIRO; Jingxi Zhu , Carnegie Mellon University; Ziqi Sun, Queensland University of Technology; Tao Wang, Nucor Steel; John Howarter, Purdue University; Fiseha Tesfaye, Åbo Akademi University

Thursday 2:00 PM
March 2, 2017
Room: 13
Location: San Diego Convention Ctr

Session Chair: Ziqi Sun, Queensland University of Technology

2:00 PM  Cancelled
Integrated Utilization of Sewage Sludge and Coal Gangue in Clinker Manufacture: Zhenzhou Yang1; Zuotai Zhang1; 1Peking University
    The present study proposed a method of integrated utilization of sewage sludge (SS) and coal gangue (CG) in eco-cement clinker manufacture with the aim of heat recovery and environment protection. The results demonstrated that the incremental amounts of SS and CG addition was favorable for the formation of tricalcium silicate (C3S) during the calcinations, but excess amount of SS addition could cause the impediment effect on C3S formation. During the calcinations, most of trace elements could be immobilized especially Zn and cannot be easily leached out. Meanwhile, it was estimated that the use of SS and CG as additives can save over 60% energy and a fair amount of natural raw materials. Given the encouraging results in the present study, the co-process of sewage sludge and coal gangue in the cement kiln can be expected with the optimum energy recovery and minimum pollution to the environment.

2:30 PM  
High Efficiency Thermoelectric Materials (skutterudites, half Heusler alloys and clathrates) and Their Mechanical Properties: Gerda Rogl1; Andriy Grytsiv1; Ernst Bauer2; Michael Zehetbauer3; Peter Rogl4; 1Christian Doppler Laboratory for Thermoelectricity, Univ. Vienna and Vienna Univ. of Technology; 2Institute of Solid State Physics, University of Technology; 3Faculty of Physics, University of Vienna; 4Institute of Materials Chemistry and Research, University of Vienna
     Thermoelectric (TE) conversion of waste heat into electricity demands optimised thermal and electrical transport in the leg material over a wide temperature range. Skutterudites, half-Heusler alloys and clathrates are known as promising candidates for environmentally friendly and low-cost TE materials in the middle to high temperature range. In this paper we present our latest p- and n-type TE materials, with high ZT values and high thermal-electric conversion efficiencies. A prerequisite for commercial use is mechanical robustness to undergo repetitive thermo cycling, but also to resist cracking or failure from any possible vibration. For these reasons, hardness, elastic moduli and fracture toughness and their dependence on composition, density and temperature were measured and evaluated as well as the coefficient of thermal expansion, which is important concerning modules, built with p- and n-type materials. An overview of all our data in comparison with other TE materials will be given.

2:50 PM  
Valuable Metals and Energy Recovery from Electronic Waste Streams: Fiseha Tesfaye1; Daniel Lindberg1; Joseph Hamuyuni2; Leena Hupa1; Pekka Taskinen2; 1Åbo Akademi University; 2Aalto University
    Currently, increasing demand for valuable metals, complexities of the available raw materials, and earth’s intrinsic limitations pose a challenge to the whole valuable metals production system. The United Nations Environment Program (UNEP) is also calling for an urgent re-think of metals recycling practices as global demand for metals continues to soar. Consequently, urban mining such as the recovery of precious metals from electronic waste (e-waste) streams through sustainable recycling processes are evolving. The sustainable recycling practices address the scarcity of primary resources while managing environmental issues related to hazardous materials from the e-waste streams. In this paper, state-of-the-art valuable metals recovery from e-waste streams by pyrometallurgical and hydrometallurgical processes are critically reviewed. And, innovative ideas for different steps of the thermochemical processes in the valuable metals and energy recovery from the e-waste streams are proposed.

3:10 PM  
Energy Recovery of Livestock Waste in Taiwan: Esher Hsu1; Chen-Ming Kuo2; 1National Taipei University; 2I-Shou University
    Energy recovery of livestock waste can not only reduce waste pollution but also generate renewable energy and further create economic benefits. Currently, most of livestock waste in Taiwan is treated as waste without efficiently recycled. This paper aims to explore and evaluate the energy recovery of livestock waste in Taiwan and further provide policy suggestions. Study results show that small farming scale of livestock industry in Taiwan leads to a lower efficiency of biogas energy recovery. Besides, the environment with relative low price of electricity and high invest cost for power generation plant is hard to provide incentive for implementation of energy recovery which has further caused difficulty on policy promotion for renewable energy recovery of livestock waste in Taiwan. Policy reform with increasing feed-in tariffs and differentiated feed-in tariffs for biogas power is suggested to stimulate energy recycling of livestock waste in Taiwan.

3:30 PM Break

3:45 PM  
Thermal Transport in High ZT Bulk Silicon Thermoelectric Materials: Seyed Aria Hosseini1; Jackson Harter2; Todd Palmer2; Lorenzo Mangolini1; P. Alex Greaney1; 1University of California, Riverside; 2Oregon State University
    Recently researchers have developed processes for synthesizing monolithic Si with large thermoelectric figure-of-merit ZT. These materials hold fantastic promise for realizing large scale waste heat recovery using materials that are inexpensive, abundant and environmentally benign. These materials obtain large ZT through a fine dispersion of nanoscale oxide and or carbide particles. In this work we elucidate the role these particles play in reducing thermal conductivity and increasing ZT. We determine the effect of impurities on scattering heat carriers and quantify the scattering cross section for phonon wavepackets with different wavelengths. We use Boltzmann transport simulations to predict the collective effect of the particle dispersion close to the Knudsen regime. Developing high ZT Si based thermoelectrics will have technological impact by introducing devices which can not only increase the efficiency of many heat engine cycles, but also bring the realization of industrial affordable solar energy cycle a step closer.

4:05 PM  
High-efficiency Natural-gas Generators for Residential Combined Heat and Power: Ji-Cheng Zhao1; 1The Ohio State University
    About 67% of primary energy for electricity generation or 25.8 quadrillion BTU (quads) per year were released as waste heat at power plants in the US, and about 75% of the electricity produced is consumed in the residential and commercial sectors, where additional 7 quads of natural gas are consumed for water heating and space heating. Combined heat and power (CHP) systems have the ability to produce electricity on-site while utilizing waste heat for heating requirements, enabling primary energy savings of ~5 quads and reduction of CO2 emissions by ~200 million metric tons per year. Energy consumption analysis shows that an optimal CHP size for US residences is ~1 kW (electricity). Techno-economic analysis indicates that high-efficiency (~35%-40%), long-life (~10 years), low-cost (<$3,000 per kW), and low emissions are key requirements for widespread deployment of CHP systems. Some key technologies including materials requirements will be discussed.

4:25 PM  
Life Cycle Assessments of Incineration Treatment for Sharp Medical Waste: Maryam Ghodrat1; Bijan Samali1; Maria Rashidi1; 1Western Sydney University
    Treatment of sharp medical waste (waste disposable syringes) produced in hospitals or health care facilities in an environmentally sound ways have raised concerns relating to public health and occupational safety. Life cycle assessment (LCA) is a decision-supporting tool in waste management practice; but relatively little research has been done on the evaluation of sharp medical waste treatment from a life cycle perspective. Our study assesses the environmental performances of medical waste incineration as a type of dominant technology for specific medical waste of average composition. Inventory models were used for waste incineration and residues landfill. Background data were derived from modelling performed in HSC Chemistry thermochemical package linked with GaBi environmental assessment tool. Two scenarios have been considered and compared: Waste disposable syringes partially replacing coke in Electric Arc Furnace (EAF) steelmaking (WSI) and conventional incineration with pure metallurgical coke without adding waste syringes (CI). The results of this study could support the medical waste hierarchy and indicate that from a life cycle perspective, replacing part of metallurgical coke with waste syringes in electric arc furnace steelmaking leads to fairly significant reduce in most of environmental impact categories.