Vol.:(0123456789) 1 3 International Journal of Environmental Science and Technology https://doi.org/10.1007/s13762-018-1875-8 ORIGINAL PAPER Nickel‑based catalysts for hydrogen production by steam reforming of glycerol O. Parlar Karakoc 1  · M. E. Kibar 1  · A. N. Akin 1  · M. Yildiz 1 Received: 2 January 2018 / Revised: 1 June 2018 / Accepted: 13 June 2018 © Islamic Azad University (IAU) 2018 Abstract As the renewable energy technologies are making progress every day, hydrogen energy technologies are taking huge part of this development. Nowadays, there are several industries using hydrogen. Also, the increase at biodiesel production amounts has increased the glycerol production as by-product. One of the main objectives of this study is to compare the efects Al 2 O 3 -, SiO 2 - and CeO 2 -supported nickel catalysts at steam reforming of glycerol in order to produce hydrogen. All catalysts were prepared by incipient to wetness method. The obtained steam reforming results showed that nickel catalysts supported on ceria showed the highest activity. Also the efect of nickel amount on CeO 2 support material has been studied. The highest hydrogen amounts were obtained with 15 wt% nickel loading. Also the increase at water/glycerol ratio increased the hydro- gen production amount. The highest hydrogen yield was obtained as 4.82 mol per glycerol mole, whereas the theoretical hydrogen yield is 7 mol, by using 15 wt% Ni/CeO 2 catalyst, water/glycerol ratio of 15 and at 650 °C reaction temperature. Keywords Hydrogen · Glycerol · Steam reforming · Catalysts Introduction The decline of fossil oil reserves and having serious envi- ronmental problems have led researchers to study on clean and sustainable resources (Zamsuri et al. 2017; Demsash and Mohan 2016). Nowadays, hydrogen has become a very important and promising energy carrier. Because it is a very important alternative to fossil fuels and is an environmen- tally friend fuel. Gasifcation, electrolysis and biological methods provide hydrogen production, but these methods have disadvantages due to excessive chemical consumption, non-renewable sources or the presence of CO 2 in the fnal product (Celik and Yildiz 2017). Hydrogen is commercially obtained with natural gas, but unfortunately this production method cannot be a recipe to the reduction in greenhouse gases (Wu et al. 2013; Carrero et al. 2017; Dang et al. 2017). In the literature, there are several studies about hydrogen production by using biomass-based compounds. Ethylene glycol, ethanol, methanol and glycerol are some of these compounds (Kim et al. 2012; Davda et al. 2005; Tuza et al. 2013). Having higher hydrogen content, non-toxicity, storage and transport properties present primacy of glycerol com- pared to the other compounds (Papageridis et al. 2016). The most important main product of the biodiesel production process is glycerol, and since it is formed in large quantities, hydrogen production from glycerol can reduce the disad- vantages of biodiesel production. (Tamosiunas et al. 2017). Steam reforming is the most preferred method for the conversion of glycerol to hydrogen according to its high reaction efciency [Silva]. The reaction of glycerol with water vapor consists of glycerol pyrolysis (Eq. 1) and the water–gas-shift reaction (Eq. 2). The overall reaction can be described by Eq. 3 as x value can difer from 0 to 3. In this overall reaction, it is important to note that: when x is equal to 0, the glycerol pyrolysis reaction occurs, whereas when x is equal to 3, the hydrogen formation reaction takes place. Each mole of glycerol consumed can provide theoretically 7 mol of hydrogen, but in the literature, less hydrogen was produced than in the theoretical quantities (Lin 2013; Koc and Avci 2017). The reaction stoichiometry tells us that carbon monoxide produced by pyrolysis is completely converted by water–gas- shift (WGS) reaction. But depending on the performance Editorial responsibility: Iskender Akkurt. * M. Yildiz myildiz@kocaeli.edu.tr 1 Department of Chemical Engineering, Kocaeli University, 41380 Kocaeli, Turkey