Energy Materials 2017: Energy and Environmental Issues in Materials Manufacturing and Processing: Opportunities in Aluminum Production, Waste Heat and Water Recovery
Sponsored by: Chinese Society for Metals, TMS: Recycling and Environmental Technologies Committee
Program Organizers: Subodh Das, Phinix,LLC; Zhancheng Guo, University of Science and Technology Beijing; Minfang Han, China University of Mining and Technology, Beijing; Teruhisa Horita, AIST; Elsa Olivetti, Massachusetts Institute of Technology; Xingbo Liu, West Virginia University
Tuesday 2:00 PM
February 28, 2017
Location: San Diego Convention Ctr
Session Chair: Elsa Olivetti, MIT
Numerical Approach for the Implementation of the Interaction of Pyrolysis Gases and Combustion Products in an Aluminium Melting Furnace: Rukiye Gültekin1; Antje Rückert1; Herbert Pfeifer1; 1IOB RWTH University
Within the scope of the project P5 of the AMAP (Advanced Metals And Processes) research cluster in Aachen a virtual remelting furnace is set up as a CFD (Computational Fluid Dynamics) simulation to investigate the resource and energy efficiency of the aluminium recycling process in melting furnaces. During the melting process of aluminium scrap (e.g. used beverage cans) a reactive flow has got a major impact on the heat transfer to the load. Thereby it is mostly dominated by gas combustion due to the heating burners in the furnace and pyrolysis/ thermolysis reaction caused by organic contamination of the charge. Obtaining more understanding of the underlying mechanisms is imperative for improving the performance of the melting and combustion process and in preservation of the equipment. In the present work, numerical simulations were carried out using the commercial software FLUENT for generating a helpful tool in evaluating operational conditions. The main perspective is to analyse the relevant operational conditions inside an aluminium melting furnace employing methane oxygen burner which is capable to run in the flameless combustion mode. To overcome the obstacle of simulating highly diluted combustion occurrence proved detailed chemistry model is involved. Another important aspect is to evaluate additional in house written codes for the evaporation and gas release due to contaminated input material. The subject of the investigation is the numerical simulation of the heating and holding process sequence as a steady state process.
Approach for Pyrolysis Gas Release Modelling and its Potential for Enhanced Energy Efficiency of Aluminium Remelting Furnaces: Henning Bruns1; Antje Rückert1; Herbert Pfeifer1; 1RWTH Aachen University
Within the scope of the AMAP research cluster in Aachen the aluminium recycling process in melting furnaces is investigated with regard to resource and energy efficiency. When organic-contaminated material is charged into the furnace, pyrolysis gases are released as soon as the material temperature exceeds 350 °C (662 °F). Those gases mainly consist of hydrocarbons, hydrogen and small fractions of other species. Thus, they are an energetic contribution to the furnace atmosphere and should be considered as such by the burner control unit in order to reduce the amount of unburnt fuel in the off-gas as well as primary energy consumption. This is achieved by post-processing data from lab-scale pyrolysis experiments in MatLab and bringing it into a format suitable for CFD and maybe also online process control tools. This presentation will give an insight into the modelling approach and the model application in ANSYS Fluent CFD.
Nitrate and Other Anion Removal from Waste Water Using the Hydroflex Technology: David Dreisinger1; Gary Kordosky2; Mike Schrock2; Todd Beers2; Jianming Lu1; Buming Chen1; 1University of British Columbia; 2Winner Water Services
Nitrate contamination is a water pollution problem in the U.S. and globally. Mining and agriculture disperse nitrate into water supplies creating significant contamination in receiving waters. There is increased demand for new water technologies to meet new regulation and more exacting effluent standards. Standard chemical/physical water treatment technologies do little to aid in meeting effluent standards for nitrate and associated anions such as selenate and sulfate. The Winner Water Hydroflex system is an adaptable technology to remove nitrate, selenate and sulfate from waste water. Hydroflex includes solvent extraction loading, scrubbing and stripping with a strong base anion exchange solvent. Nitrate may be stripped as a strong solution of calcium nitrate using a milk of lime strip solution. The loading and stripping data from testing of Hydroflex on a waste water sample will be presented and discussed along with an economic model demonstrating the cost effectiveness of the technology.
3:00 PM Invited
Sustainability and Applicability of Light Metals Producing Processes: Subodh Das1; Adam Gesing2; 1Phinix,LLC; 2Gesing Consultants Inc.
The demand of light metals such as aluminum, magnesium, titanium and lithium is raising rapidly – thanks to higher application in transportation and electronic industries. However,decades and even century old processes to produce them may have changed in scale and efficiency but not in raw materials and basic principles employed. With the advent of global sustainability trends where public demands and consumers are willing to pay for lower carbon foot print products, we need to focus on low cost, energy and environmental impact scrap -based processes and products. This presentation will make a global case supporting these ideas and suggest a path forward to “create our own future”.
3:30 PM Break
The Influence of Water Vapour on the Fuming Rate in a Ferromanganese System: Sarel Gates1; Gabriella Tranell2; Gerrit Kornelius1; Ida Kero3; 1University of Pretoria; 2Norwegian University of Science and Technology (NTNU); 3SINTEF Materials and Chemistry
During the casting of ferromanganese alloys, a considerable amount of dark fumes are generated when the Mn vapour oxidise in the atmosphere. Previous studies indicate that these fumes can be reduced by increasing the humidity above the melt. However, the reduction mechanism is not fully understood. In an attempt to understand the reduction mechanism, the influence of a humidity change on the fuming rate was studied. Laboratory scale experiments were conducted where an impinging jet blew air with a varying humidity onto the melt where dust was captured to determine relative mass fluxes. When the wet air experiments’ fume fluxes were compared to the dry air experiment, it was found that the increase in humidity resulted in a significant reduction (between 33% and 79%), confirming industrial observations. Dust composition from the experiments as well as dust reduction mechanisms are presented and discussed.
Fluoropolymer Coated Condensing Heat Exchangers for Low-grade Waste Heat Recovery: Youliang He1; Afsaneh Edrisy2; Robert Triebe3; Mehdi Mehdi4; 1Natural Resources Canada; 2University of Windsor; 3Thermal Energy International Inc. ; 4University of Windsor/Canmet Materials
Low-grade waste heat from industrial processes usually has temperatures lower than ~232°C, and thus has low thermal and economic value. However, it is abundant and its total work potential is huge. To effectively recover low-temperature waste heat, the exhaust streams usually need to be cooled to temperatures below the dew points to recover both the sensible and latent heats, which causes severe corrosion problems in the heat exchangers. In this research, a fluoropolymer-based composite coating was applied to heat exchangers made of common metals (e.g. stainless steel, aluminum, carbon steel, etc.) to protect the surfaces contacting the waste streams. Corrosion tests were conducted in 80% sulphuric acid at 85°C for more than 1500 hours and no corrosion was detected. The composite material has much higher thermal conductivity than virgin fluoropolymer, and can be continuously utilized at temperatures up to ~260°C. It also shows excellent adhesion strength to the substrate.
Study on Treatment of Chromium Slag by Metallurgical Sintering Process: Qingcai Liu1; Fei Meng1; Lijun Jiang1; Ming Kong1; Shan Ren1; Guang Hu1; Qi Zhao1; 1Chongqing University
The metallurgical sintering method was employed to process chromium slag (CS) which contains a significant fraction of a leachable Cr(VI). And CS was added into the sinter mixtures with mass fraction of 2%, 4%, 8%, and 10%. The effects of CS on physical strength, metallurgical properties of sinter, and Cr(VI) concentration in sinter were studied. The results showed that the shattering index, tumble index both tend to first increased and then decreased with increasing addition of CS. The physical strength of sinter reached the best when the addition ratio of chromium slag was 2%. With the addition of CS increased from 0% to 10%, the reducibility index of sinter increased from 78.36% to 82.26%, whereas the low temperature reduction degradation index (RDI+3.15mm) decreased from 64.89% to 58.35%. The Cr(VI) concentration in sinters increased from 9.76 to 21.61 μg•g-1, and much lower than Cr(VI) concentration in initial chromium slag (1600 μg•g-1).