Title:
Combustion of Sunflower Shells in Conventional and Swirling Fluidized Beds: A Comparative Study between Two Combustion Techniques
Author(s):
Arromdee, P., Kuprianov, V.I.
Document(s):
Paper
Abstract:
This work reports the experimental results from a comparative study of burning sunflower shells in two fluidized-bed combustors (FBCs) with different hydrodynamics of a gas–solid bed. In the bubbling FBC, a bubble-cap air distributor was used to fluidize the bed, whereas in the swirling FBC an annular spiral air distributor generated the swirling fluidized bed. During the experiments on the swirling FBC, primary air was introduced into the bed through the air distributor, while secondary air was injected tangentially into the bed splash zone to facilitate rotational gas–solid flow. Combustion and emission performance of the two FBCs were the focus of study. In both case studies, the trials were carried out at fuel feed rates of 60 kg/h and 45 kg/h, while ranging excess air from 20% to 80% at a fixed combustor load. For each test run, temperature and gas concentrations (O2, CO, CxHy and NO) were measured along axial and radial directions in the combustor, as well as in the stack flue gas. The radial and axial temperature profiles in the reactors were found to be rather uniform. However, the behavior of the gas concentrations showed influences of the combustor hydrodynamics and operating conditions. The injection of secondary air into the bed splash zone significantly affected decomposition of CO, and, consequently, the behavior of NO in the swirling FBC. Excess air of 50–60% seems to be an optimum ensuring high combustion efficiency (of about 99%) at minimized emissions of CO, CxHy, and NO of both combustors. For the two FBCs, the emissions were fairly the same at optimal operating conditions. However, as followed from analysis of the axial gas concentration profiles, the swirling FBC can be designed with the noticeably smaller height.
Keywords:
emissions, fluidized bed, sunflower shell, combustion efficiency
Topic:
Thermochemical conversion - Combustion and co-combustion
Subtopic:
Combustion and co-combustion for large utility and industrial scale applications
Event:
18th European Biomass Conference and Exhibition
Session:
VP2.4.15
Pages:
1156 - 1166
ISBN-13:
978-88-89407-56-1
ISBN-10:
88-89407-56-5
Paper DOI:
10.5071/18thEUBCE2010-VP2.4.15
Price:
FREE
