scholarly journals A Sustainable Process to Produce Manganese and Its Alloys through Hydrogen and Aluminothermic Reduction

Processes ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 27
Author(s):  
Jafar Safarian

Hydrogen and aluminum were used to produce manganese, aluminum–manganese (AlMn) and ferromanganese (FeMn) alloys through experimental work, and mass and energy balances. Oxide pellets were made from Mn oxide and CaO powder, followed by pre-reduction by hydrogen. The reduced MnO pellets were then smelted and reduced at elevated temperatures through CaO flux and Al reductant addition, yielding metallic Mn. Changing the amount of the added Al for the aluminothermic reduction, with or without iron addition led to the production of Mn metal, AlMn alloy and FeMn alloy. Mass and energy balances were carried out for three scenarios to produce these metal products with feasible material flows. An integrated process with three main steps is introduced; a pre-reduction unit to pre-reduce Mn ore, a smelting-aluminothermic reduction unit to produce metals from the pre-reduced ore, and a gas treatment unit to do heat recovery and hydrogen looping from the pre-reduction process gas. It is shown that the process is sustainable regarding the valorization of industrial waste and the energy consumptions for Mn and its alloys production via this process are lower than current commercial processes. Ferromanganese production by this process will prevent the emission of about 1.5 t CO2/t metal.

Author(s):  
M. A. Porter ◽  
D. H. Martens

The design requirements for a large shell and tube vertical heat exchanger (to be used in a sulfur recovery tail gas treatment unit) included startup, shutdown and upset conditions that would subject the exchanger to significant temperature changes. The exchanger was designed to the requirement of the ASME Boiler and Pressure Vessel Section VIII Division 1 [1]. A detailed analysis of the thermal profiles and related stresses was performed to confirm the use of a flexible tube sheet design. The heat exchanger uses high pressure superheated steam on the shell side to heat a low pressure process gas on the tube side. The heat exchanger was sized and thermally rated, using commercially available analysis software. The proposed design was analyzed by Finite Element methods that included both thermal and stress analysis. These evaluations confirmed that a flexible tube sheet design was satisfactory when using specific dimensions.


2015 ◽  
Vol 226 ◽  
pp. 215-218
Author(s):  
Wojciech Bialik ◽  
Bolesław Machulec

The paper presents an analysis of the possibilities of using the enthalpy of post-reaction gases from the ferrosilicon smelting process to produce electricity. Ferrosilicon smelting in the submerged arc furnace is one of the most energy-consuming electro thermal processes. Post-reaction gases, generated during the silica reduction process with carbon, contain significant amounts of energy. In the past the issue of energy recovery from the ferrosilicon process has been repeatedly taken, but for the Polish ferroalloy industry it is still valid. In order to determine the amount of energy possible for recovery calculations based on mass and energy balances has been carried out and determined the stream enthalpy of post processing gas. For preparing the balance sheets has been used operational data from the 20 MVA furnace and the overall reaction of the silica reduction process. It was assumed that the reduction process occurs at a temperature of 1650°C, and the temperature of leaving post-reaction gas, whose main ingredients are oxides CO and SiO, is 750°C.


Author(s):  
Marcelo Bernardes Secron ◽  
Shanty Navarro Hurtado ◽  
Daniella dos Santos Medeiros ◽  
Wilson Jose´ de Oliveira

The Preliminary Environmental Assessment (PEA) at Petrobras consists, in general terms, of an internal technical process, prior to environmental permitting, to verify the environmental feasibility of a project and identify the main environmental issues. It will also add to the future Environmental Impact Assessment Study (EIA). The technical guidelines for the PEA are prepared by the multidisciplinary team at the Petrobras Environmental Assessment Engineering Group (EAMB) of ENGENHARIA/IETEG/ETEG and are based on the characteristics of the project. The PEA is one of the elements of the environmental impact assessment, providing an initial assessment of the environmental aspects of the project (Screening). It also supports the assessment and determination of route and location alternatives of pipelines and industrial plants. The UTGCA (Caraguatatuba Gas Treatment Unit) will process gas and condensate from the Mexilha˜o Field, on Santos Basin – SP. This paper presents the procedures and conclusions of the PEA prepared for the UTGCA project by PETROBRAS/ENGENHARIA/IETEG/ETEG/EAMB.


2019 ◽  
pp. 646-654
Author(s):  
Jan Iciek ◽  
Kornel Hulak ◽  
Radosław Gruska

The article presents the mass and energy balances of the sucrose crystallization process in a continuous evaporating crystallizer. The developed algorithm allows to assess the working conditions of the continuous evaporating crystallizers and the technological and energy parameters. The energy balance algorithm takes into account the heat released during the crystallization of sucrose, which was analyzed in this study, heat losses to the environment and heat losses due the vapor used for inert gas removal.


2019 ◽  
Vol 120 ◽  
pp. 144-155 ◽  
Author(s):  
Andrea Maria Rizzo ◽  
Marco Pettorali ◽  
Renato Nistri ◽  
David Chiaramonti

2017 ◽  
Vol 11 (6) ◽  
pp. 2799-2813 ◽  
Author(s):  
Colin R. Meyer ◽  
Ian J. Hewitt

Abstract. Meltwater is produced on the surface of glaciers and ice sheets when the seasonal energy forcing warms the snow to its melting temperature. This meltwater percolates into the snow and subsequently runs off laterally in streams, is stored as liquid water, or refreezes, thus warming the subsurface through the release of latent heat. We present a continuum model for the percolation process that includes heat conduction, meltwater percolation and refreezing, as well as mechanical compaction. The model is forced by surface mass and energy balances, and the percolation process is described using Darcy's law, allowing for both partially and fully saturated pore space. Water is allowed to run off from the surface if the snow is fully saturated. The model outputs include the temperature, density, and water-content profiles and the surface runoff and water storage. We compare the propagation of freezing fronts that occur in the model to observations from the Greenland Ice Sheet. We show that the model applies to both accumulation and ablation areas and allows for a transition between the two as the surface energy forcing varies. The largest average firn temperatures occur at intermediate values of the surface forcing when perennial water storage is predicted.


2008 ◽  
Vol 12 (4) ◽  
pp. 75-88 ◽  
Author(s):  
Nenad Ferdelji ◽  
Antun Galovic ◽  
Zvonimir Guzovic

Limitations of traditional first-law analysis, based upon thermodynamic performance of process unit coupled with mass and energy balances, are not a serious limitation when dealing with familiar systems. However, when dealing with more uncongenial, complex ones, it provides incomplete insight for such evaluation. These limitations came from the fact that first-law analysis does not indicate the sources or magnitudes of entropy production, which is, by the second law, essential criterion for scaling losses. An evaluation of plant performance will usually require a comparison of the thermodynamic performance of process units with available data from existing plants. Therefore, exergy analysis is more than useful, providing information about magnitudes of losses and their distribution throughout the system as well. Such analysis is very thankful at the level of process units but applied on higher system levels e.g. the comparison of overall plant performance (total system) or the performance of subsystems, represents the valuable method for indicating where research resources can be directed to best advantage.


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