The present study investigates the combustion of four kinds of biomass in a circulating fluidized bed. The
combustion chamber is a steel cylinder with 145 mm inner diameter and 2 m height. Tests were conducted
on wheat straw, sawdust-wood, cottonseed burs, and corncobs. Excess air was varied for each
fuel. Temperature, heat flux and gas emissions were measured along the combustion chamber and at
the chimney inlet. Results showed that sawdust-wood produces the highest values of CO emissions
(about 3000 mg/Nm3). On the other hand, cottonseed burs produce the lowest values of CO emissions
(about 250 mg/Nm3). The SO2 emissions were very low in all tests (less than 20 mg/Nm3). The lowest
emission value occurred at an excess air ratio (EA) of 1.24 except for cottonseed burs where it was 1.4.