Steam gasification of rice husk: effects of feedstock heterogeneity and heat-mass transfer

ABSTRACT

The effects of important practical parameters, specifically feedstock heterogeneity and heat-mass transfer on steam gasification of rice husk were investigated and quantified. Through proximate and ultimate analysis of ten rice husk types, the heterogeneity was expressed not only between different types but also within the same rice husk type. TGA-DTG curves showed notable differences in the thermal behaviors of rice husk during pyrolysis. The time required to gasify the same quantity of rice husk can vary in a ratio of 1–1.5 depending on the type. The Si content in rice husk showed an inhibitory effect to the char reactivity during steam gasification. An empirical factor of 1.3 could be applied to the conversion rate of rice husk for every 1-cm increase in the bed thickness. Results of this study could contribute to the improvement of existing systems or the design of new efficient rice husk gasifiers.

KEYWORDS:

• Biomass
• conversion
• kinetics
• Macro-thermogravimetric analyzer
• rice husk
• steam gasification

Acknowledgments

The authors would also like to acknowledge the support provided by the French Agricultural Research Centre for International Development (CIRAD) for analysis of samples.

Additional information

Funding

This work was supported by the University of Science and Technology of Hanoi (USTH) under grant number [USTH.EN.01/19-20].

Notes on contributors

Hong Nam Nguyen

Hong Nam Nguyen is a lecturer-researcher at the University of Science and Technology of Hanoi (USTH) - Vietnam Academy of Science and Technology in Hanoi, Vietnam.  His research expertise is thermochemical conversion processes applied to solid fuels. He particularly works on slow pyrolysis, gasification, and co-firing technologies with the aim to promote clean and sustainable energy sources.

Laurent Van De Steene

Laurent Van De Steene is a senior researcher at the French Agricultural Research Center for International Development (CIRAD) in Montpellier, France. His research expertise and interest are gasification and combustion of biomass resources. In addition, he focuses on developing the International network of bioenergy laboratories in Europe, Africa, Latin America, and Asia, to facilitate human capacity building, research collaboration and technology transfer.