In recent industrial scale bio-oil combustion tests, bio-oil has been found to be technically suitable for replacing heavy fuel oil in district heating. In addition, it has also been found out that limited possibilities for further lowering particulate emissions exist, since the majority of the particulates are typically incombustible matter. Curves for NOx-emissions of fast pyrolysis bio-oil combustion for air-assisted atomization burners are presented in the paper.
Current burner designs are quite sensitive to the changes in the quality of the bio-oil, which may cause problems in ignition, flame detection and flame stabilization. Therefore, in order to be able to create reliable bio-oil combustion systems that operate at high efficiency, bio-oil grades should be standardized for combustion applications. Careful quality control, combined with standards and specifications, all the way from feedstock harvesting through production to end-use is recommended in order to make sure that emission targets and limits in combustion applications are achieved. Also the cost-effectiveness of the total package is extremely important.