Co-combustion of rice husk pellets and moisturized rice husk in a fluidized-bed combustor using fuel staging at a conventional air supply

• Main Authors: Pichet Ninduangdee, Vladimir I. Kuprianov
• Format: Article
• Language: English
• Published: Prince of Songkla University 2018-10-01
• Series: Songklanakarin Journal of Science and Technology (SJST)
• Subjects: fluidized bed; rice husk; co-combustion; fuel staging; NO reduction
• Online Access: https://rdo.psu.ac.th/sjstweb/journal/40-5/14.pdf

This paper presents an experimental study on co-combustion of two types of rice husk with substantially different properties in a fluidized-bed combustor using fuel staging for lowering NO emission. Rice husk pellets were burned as a base (or primary) fuel, whereas moisturized rice husk was injected downstream from the primary combustion zone as a secondary fuel. The experiments were conducted at 200 kWth heat input to this reactor with a bottom air supply, while the energy fraction of the secondary fuel in the total heat input ranged from 0 to 0.25, and excess air was within 2080% for each co-firing option. The study revealed significant effects of the operating parameters on combustion and emission performance of the combustor. Compared to burning of the base fuel, a nearly 40% NO emission reduction is achievable with fuel staging, while controlling the CO and CxHy emissions from the combustor to acceptable levels. However, fuel staging causes some deterioration in the combustion efficiency.