Hydrogen and Carbon Nanotubes from Pyrolysis-Catalysis of Waste Plastics: A Review

More than 27 million tonnes of waste plastics are generated in Europe each year representing a considerable potential resource. There has been extensive research into the production of liquid fuels and aromatic chemicals from pyrolysis-catalysis of waste plastics. However, there is less work on the production of hydrogen from waste plastics via pyrolysis coupled with catalytic steam reforming. In this paper, the different reactor designs used for hydrogen production from waste plastics are considered and the influence of different catalysts and process parameters on the yield of hydrogen from different types of waste plastics are reviewed. Waste plastics have also been investigated as a source of hydrocarbons for the generation of carbon nanotubes via the chemical vapour deposition route. The influences on the yield and quality of carbon nanotubes derived from waste plastics are reviewed in relation to the reactor designs used for production, catalyst type used for carbon nanotube growth and the influence of operational parameters

Catalytic Treatment of Opium Alkaloid Wastewater via Hydrothermal Gasification

7th Global Conference on Global Warming (GCGW) -- JUN 24-28, 2018 -- Izmir, TURKEYWOS: 000587895700020The wastewater from an opium processing plant should meet the standards as specified in the 'Water Pollution Control Regulation (WPCR), 2004' before being discharged safely into the receiving medium. Treatment of opium alkaloid wastewater is not sufficient using the existing combined methods of aerobic/anaerobic and chemical treatment. Hydrothermal gasification (HTG) is proposed as an alternative treatment in this study. the other aim of this study is to show the ability to manufacture CH4 and H-2 as renewable energy sources and to determine to what extent the removal of chemical oxygen demand (COD) is. Studies were carried out in batch autoclave reactor systems without catalyst, with original red mud (RM), activated RM, and nickel-impregnated (10, 20, and 30%) forms. Reduction with NaBH4 was done to the nickel-impregnated forms of RM to increase the catalytic activity. Yields of CH4 and H-2 increased from 16.8 to 28.6 mol CH4/kg C in wastewater and from 20.3 to 33.3 mol H-2/kgC in wastewater with 20% impregnated nickel and reduced red mud as the highest at 500 degrees C. the COD of the wastewater was lowered by 81-85% approximately while the TOC content decreased by 85-90%.Ege University-Aliye Uster Vakfi; Ege University-EBILTEMEge University [15 MUH 055, 16 MUH 133]We gratefully appreciate the financial support of Ege University-Aliye Uster Vakfi and Ege University-EBILTEM (Project No's: 15 MUH 055 and 16 MUH 133). We also give thanks to Mr. G. Serin for his support in the pre-treatment step of the biomasses and for the help during the experimental studies and analysis

Glycerol Steam Reforming for Hydrogen Production over Nickel Supported on Alumina, Zirconia and Silica Catalysts

The aim of the work was to investigate the influence of support on the catalytic performance of Ni catalysts for the glycerol steam reforming reaction. Nickel catalysts (8 wt%) supported on Al2O3, ZrO2, SiO2 were prepared by the wet impregnation technique. The catalysts’ surface and bulk properties, at their calcined, reduced and used forms, were determined by ICP, BET, XRD, NH3-TPD, CO2-TPD, TPR, XPS, TEM, TPO, Raman, SEM techniques. The Ni/Si sample, even if it was less active for T <600 °C, produces more gaseous products and reveals higher H2 yield for the whole temperature range. Ni/Zr and Ni/Si catalysts facilitate the WGS reaction, producing a gas mixture with a high H2/CO molar ratio. Ni/Si after stability tests exhibits highest values for total (70%) and gaseous products (45%) glycerol conversion, YH2 (2.5), SH2 (80%), SCO2 (65%), H2/CO molar ratio (6.0) and lowest values for SCO (31%), SCH4 (3.1%), CO/CO2 molar ratio (0.48) among all samples. The contribution of the graphitized carbon formed on the catalysts follows the trend Ni/Si (I D /I G = 1.34) < Ni/Zr (I D /I G = 1.08) < Ni/Al (I D /I G = 0.88) and indicates that the fraction of different carbon types depends on the catalyst’s support nature. It is suggested that the type of carbon is rather more important than the amount of carbon deposited in determining stability. It is confirmed that the nature of the support affects mainly the catalytic performance of the active phase and that Ni/SiO2 can be considered as a promising catalyst for the glycerol steam reforming reaction