ABSTRACT
The cement industry can reduce its CO2 emissions by electrifying the calciner. It can avoid emissions from fuel combustion and produce pure CO2 from the calcination reaction (CaCO3 â CaO + CO2) for direct capture. A differential-algebraic equation (DAE) model of an electrified rotary calciner was developed and validated against experimental results. The heat transfer coefficient was around 30 W/(m2K), with the calciner inclined at 15°. This value increased to 80 W/(m2K) by reducing the inclination to 2°. The rotary calciner for producing 1 Mton/yr clinker with an internal diameter of 5 m needs a length of 485 m to reach a calcination degree of 94 %. The large system size suggests that this calciner may not be suitable for full-scale production. However, it can still be used for small-scale green production of calcined limestone.
ABSTRACT
Multi-walled carbon nanotubes-fluorine-co-doped TiO2 composite was synthesized by the solid state method. The prepared photocatalysts were characterized by using XRD, FTIR and FE-SEM. In addition, the samples were evaluated for antimicrobial activity and photocatalytic activity. The composites exhibited enhanced absorption properties in the UV light range compared to pure TiO2. The MWCNTS-F-co-doped TiO2 composites showed significant photocatalytic activity in the generation of oxygen.
Subject(s)
Anti-Infective Agents/pharmacology , Fluorine/chemistry , Nanocomposites/chemistry , Nanotubes, Carbon/chemistry , Titanium/pharmacology , Ultraviolet Rays , Azo Compounds/chemistry , Bacteria/drug effects , Catalysis/radiation effects , Microbial Sensitivity Tests , Nanocomposites/ultrastructure , Nanotubes, Carbon/ultrastructure , Spectrometry, X-Ray Emission , Spectroscopy, Fourier Transform Infrared , X-Ray DiffractionABSTRACT
We show how an alternating electric field can be used to assemble carbon nanocones (CNCs) and align these assemblies into microscopic wires in a commercial two-component adhesive. The wires form continuous pathways that may electrically connect the alignment electrodes, which leads to directional conductivity (â¼10(-3) S/m) on a macroscopic scale. This procedure leads to conductivity enhancement of at least 2-3 orders of magnitude in the case where the CNC fraction (â¼0.2 vol %) is 1 order of magnitude below the percolation threshold (â¼2 vol %). The alignment and conductivity are maintained on curing that joins the alignment electrodes permanently together. If the aligned CNC wires are damaged before curing, they can be realigned by an extended alignment period. This concept has implications in areas such as electronic packaging technology.
