WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7150

Browse

Filters

20252

Settings

Author: search.filters.author.Yildiz, GurayDepartment: search.filters.department.İzmir Institute of Technology

Search Results

Now showing 1 - 2 of 2
  • Article
    Citation - WoS: 1
    Citation - Scopus: 2
    Effect of Preparation Method on the Activity of Red Mud Based Catalysts in Hydrogen Production From Biomass
    (Elsevier Ltd, 2025) Yıldız, Güray; Akbas, Nazire Merve; Duman, Gozde; Simsek, Osman; Yildiz, Guray; Wang, Weitao; Yanik, Jale; 03.06. Department of Energy Systems Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Biomass gasification is a promising technology for hydrogen production. This study presents H2 production from olive tree pruning (OTP), employing a fixed dual-bed reactor that combines OPT gasification and volatile reforming. The thermal steam gasification of OTP was performed at 850 degrees C, followed by the catalytic gasification of volatiles at different temperatures. Red mud (RM) and nickel loaded red mud (Ni-RM) catalysts were used as catalytic bed material. The effects of different operating parameters, i.e. catalytic bed temperature, catalyst preparation method (thermal reduction & plasma reduction), and nickel ratios in catalyst on the yield and composition of produced gases were investigated. The catalyst prepared by reduction under non-thermal plasma showed no effect on the gasification due to the insufficient temperature for the reduction of Fe2O3 and NiO. The results indicated that the bottom bed temperature had a significant effect on the H2 yield, especially in the catalytic experiments. The RM alone shows almost the same activity with Ni-RM on the H2 yield; 1076 mL gas/g OTP and 1128 mL gas/g OTP, respectively. The results of present study showed that reduced RM had as much catalytic activity as Ni loaded reduced RM in hydrogen production.
  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    Co-Pyrolysis of Waste Wind Turbine Blades in a Molten Polyolefin Medium
    (Elsevier, 2025) Yıldız, Güray; Yildiz, Magdalena Joka; Kalinowska, Monika; Wang, Jiawei; Yildiz, Guray; 03.06. Department of Energy Systems Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    This study investigates the pyrolysis and co-pyrolysis processes of waste wind turbine blades (WWTB) and polyolefins (POs) at 450 degrees C in a round bottom tank reactor. The study contains three experimental sets: 1) batch pyrolysis of POs; 2) continuous pyrolysis of WWTB; 3) continuous feeding of WWTB into a molten PO medium, which was previously fed to the round bottom tank reactor batch-wise. Individual WWTB pyrolysis yields a modest 18.7 wt% of liquid, predominantly influenced by elevated ash and fixed carbon content. Conversely, copyrolysis demonstrates positive synergies, with escalating polyolefin content boosting liquid yields, reaching a peak at 61.5 wt% with a WWTB:POs mixture (25:75, wt%), while concurrently suppressing gas production to 21.6 wt%. The primary chemical groups found in the liquid obtained from WWTB are phenol and phenolic compounds, with their abundance diminishing as the POs ratio in feedstocks increases. Analysis of noncondensable gases from WWTB reveals that approximately 57.7 wt% are oxygen-containing, predominantly CO and CO2. Co-pyrolysis with POs at a 25:75 (wt%) ratio yields 47.1 wt% C3H6, resembling POs pyrolysis. The resulting solid products are rich in carbon and contains high ash. This research not only offers a detailed product analysis of WWTB but also sheds light on the dynamics of its co-pyrolysis with POs. Doing so contributes crucial insights into the transformative potential of pyrolysis and co-pyrolysis processes, covering the way for sustainable waste-to-resource solutions.