Automatically generated rough PDF by ProofCheck from River Valley Technologies Ltd DE GRUYTER International Journal of Chemical Reactor Engineering. 2018; 20170202 Shyam P. Tekade 1 / Diwakar Z. Shende 2 / Kailas L. Wasewar 2 Hydrogen Generation in an Annular Micro-Reactor: An Experimental Investigation and Reaction Modelling by Shrinking Core Model (SCM) 1 Department of Chemical Engineering, Gharda Institute of Technology, Lavel, Khed 415708, India 2 Department of Chemical Engineering, Visvesvaraya National Institute of Technology, Nagpur 440010, India, E-mail: diwakar.shende@gmail.com Abstract: Hydrogen can be one of the key elements as source of future energy requirement. Water splitting reaction is an important route for generation of hydrogen as maximum fraction of hydrogen constitute in water. The present work describes the experimental investigation for generation of hydrogen through water splitting reaction in fow conditions with the aid of metal aluminum and sodium hydroxide as an activator. The hydrogen genera- tion through water splitting reaction at various concentrations of NaOH, viz. 0.5 N and 1 N and the fow rates ranging from 0.2 to 10 ml/min was studied. The yield of hydrogen generated is reported for each NaOH con- centration and fow rate. The yield of hydrogen generated at all the considered concentrations and fow rates was found to be greater than 98 %. The shrinking core model has been modifed and developed for predicting the conversion of aluminum in the reaction system as per the prevailing conditions and rate controlling mech- anism. The RMSE value of predicted conversion of Al was found to be 0.0351 which signify that the model agrees well with the experimental data. Keywords: water splitting, fow conditions, yield, hydrogen generation, rate controlling mechanism DOI: 10.1515/ijcre-2017-0202 Received: October 25, 2017; Revised: December 15, 2017; Accepted: March 12, 2018 1 Introduction An alternative to the depleting petroleum reserves and the alarming pollution scenario due to the excessive use of fossil fuels is inescapable for the sustainable future. The uncontrolled use of fossil fuels for harnessing the energy leads to greenhouse gases, afect environmental stresses and the major reasons for human health problems (Adnan, Ibrahim, and Murat 2006; Pavlos and Andreas 2017; George, Mildred, and Michelle 2004). To address the associated problems, it is inevitable to fnd the new energy sources which are sustainable and superior to the fossil fuels. One of such energy sources or energy carrier is hydrogen (Magdalena and Veziroglu 2005; Victor and Veziroglub 2001). Hydrogen is the most abundant element on earth’s surface. It is light, non- toxic, colourless, odourless and contains very high energy (120 MJ/Kg). It has wide ignition limits (4–75 %), low energy of ignition with air (0.02 MJ), explosive in a narrower range (15–59 %), maximum burning velocity in air (3.46 m/s at STP), higher auto ignition temperature (585 ° C), very high octane number of 100 (Ibrahim and Canan, 2016), and most importantly the combustion of hydrogen with oxygen generates only water as product unlike that of fossil fuels producing dangerous CO and CO 2 on combustion (Tzimas et al. 2003; Saxena et al. 2008). Hydrogen possesses all desirable characteristics to be called as perfect fuel (Das 1996). The constraints for the efective use of hydrogen as a fuel (hydrogen economy) are its availability, production, storage and transportation. Though the hydrogen is one of the most abundant elements on the earth, the molecular hydro- gen gas, H 2 is very rare. Because of its high reactivity, hydrogen can easily combined with other elements to form the compounds. Majority of hydrogen in the nature is shared by water, remaining by the hydrocarbons; other natural as well as artifcial compounds (Louis and Andreas 2001; Nicola and Vincenzo 2011). Low density (0.08988 g/l), extreme fammability, wide explosive limits, low boiling point and poor compressibility make it very dificult to store or transport the hydrogen at high pressures (Tzimas et al. 2003; Ezgi, Tekkaya, and Yuda 2016; Deng, Ferreira, and Sakka 2008; Zuttel 2003). A small leak to cylinder or pipe carrying hydrogen and a Diwakar Z. Shende is the corresponding author. © 2018 Walter de Gruyter GmbH, Berlin/Boston. 1 Brought to you by | University of Pennsylvania Authenticated Download Date | 4/15/18 3:21 AM