title: Practical achievements on biomass steam gasification in a rotary tubular coiled-downdraft reactor.
abstract: Today, the impending stringent environmental norms and concerns about the depletion of fossil fuel reserves have added impetus on development of cutting edge technologies for production of alternative fuels from renewable sources, like biomass. The concept of biomass pyro-gasification offers a platform for production of (a) hydrogen, (b) hydrocarbons and (c) value added chemicals, etc. In this context, there exists potential for hydrogen production from biomass by superheated steam gasification. Apart from H2, gaseous products of biomass steam gasification contain CO, CH4and other hydrocarbons that can be converted to hydrogen through cracking, steam reforming and water gas shift reactions. In the present work, the characteristics of biomass steam gasification in an indigenously designed rotary tubular coiled-downdraft reactor for high value gaseous fuel production from rice husk was studied through a series of experiments. The robust reactor system enhances biomass conversion to gaseous products by improved mass and heat transfer within the system induced by a coiled flow pattern with increased heat transfer area. Also, the system has improved upon the reliability of operation and offered greater continuity of the process and easier control in comparison with a conventional process by making use of an innovative gas cooler assembly and efficient venturi-mixing system for biomass and steam. Subsequently, the effects of reactor temperature, steam-to-biomass ratio and residence time on overall product gas yield and hydrogen yield were investigated. From the experimental results, it can be deduced that an optimum reactor temperature of 750 °C, steam-to-biomass ratio of 2.0 and a residence time of 3.0 min contributed highest gas yield (1.252 Nm3kg-1moisture-free biomass). Based on the obtained experimental results, a projected potential hydrogen yield of 8.6 wt% of the moisture-free biomass could be achieved, and is also practical for production of pure hydrogen.
authors: Corporate R&D Centre, Bharat Petroleum Corporation Ltd, Greater Noida, India rennyam@bharatpetroleum.in.
authors: Renny
authors: R
authors: Andrew
authors: Corporate R&D Centre, Bharat Petroleum Corporation Ltd, Greater Noida, India.
authors: D T
authors: DT
authors: Gokak
authors: College of Engineering, University of Petroleum and Energy Studies, Dehradun, India.
authors: Pankaj
authors: P
authors: Sharma
authors: Corporate R&D Centre, Bharat Petroleum Corporation Ltd, Greater Noida, India.
authors: Shalini
authors: S
authors: Gupta
mesh_terms: D056804:Biofuels; D018533:Biomass; D001709:Biotechnology / Q000295:instrumentation* / Q000379:methods*; D004867:Equipment Design; D006859:Hydrogen / Q000378:metabolism*; D012275:Oryza; D013227:Steam; D013696:Temperature
chemical_list: D056804:Biofuels; D013227:Steam; D006859:Hydrogen
keywords: Biomass steam gasification; cracking; hydrogen yield; product gas yield; rotary tubular coiled-downdraft reactor; steam reforming; steam-to-biomass ratio; water gas shift reaction