Thermal analysis on the pyrolysis of tetrabromobisphenol A (TBBPA) and Electric Arc Furnace Dust mixtures

The pyrolysis of Tetrabromobisphenol A (TBBPA) mixed with Electric Arc Furnace Dust (EAFD) was studied using thermogravimetric analysis (TGA) and theoretically analysed using thermodynamic equilibrium calculations. Mixtures of both materials with varying TBBPA loads (1:1, and 1:3) were prepared and pyrolyzed in a nitrogen atmosphere under dynamic heating conditions at heating rates of 5 and 10 ⁰C/min. The mixtures degraded through several steps including decomposition of TBBPA yielding mainly HBr, bromination of metal oxides, followed by their evaporation in the sequence of CuBr3, ZnBr2, PbBr2, FeBr2, MnBr2, KBr, NaBr, CaBr2 and MgBr2, and finally reduction of the remaining metal oxides by the char formed from decomposition of TBBPA. Thermodynamic calculations suggest the possibility of selective bromination of zinc and lead followed by their evaporation leaving iron in its oxide form, while the char formed may serve as a reduction agent for iron oxides into metallic iron. However, at higher TBBPA volumes, iron bromide forms, which can be also evaporated at a temperature higher than those of ZnBr2 and PbBr2. Results from this work provide practical insight into selective recovery of valuable metals from EAFD while at the same time recycling the hazardous bromine content in TBBPA

Smart sustainable greenhouses utilizing microcontroller and IOT in the GCC countries; energy requirements & economical analyses study for a concept model in the state of Qatar

A smart sustainable greenhouse concept model (SSGHCM) was built to demonstrate the effectiveness and the profitability of using renewable energy and smart control systems in closed agriculture environment. SSGHCM is powered by solar photovoltaic energy and utilizes waste water management. Microcontrollers and multiple sensing arrangement were installed to completely control the irrigation, temperature and humidity of the greenhouse autonomously. Two types of control systems were used; microcontrollers connected to LabVIEW and a wireless control system based IOT. It was found that the installed PV capacity with storage can support the required energy. IOT combined with microcontrollers, as well as using the renewable energy in greenhouses in the GCC countries can make vegetable growth a profitable investment. Water recycling and management system is contributing to reduction of water need to around 40% of that needed for traditional greenhouses. Condensate from the AC contributes to around 65% of the needed water for irrigation by collecting the condensate from these systems. All of these factors will further improve the profitability of smart sustainable greenhouses and contribute largely to food security in the GCC countries. Scaled to commercial greenhouses, the economic analysis showed an attractive investment with 340% ROI and 5 years of payout period