Composition and sintering characteristics of ashes from co-firing of coal and biomass in a laboratory-scale drop tube furnace

• Published in: Energy (Oxford) Vol. 69; pp. 562 - 570
• Main Authors: Luan, Chao, You, Changfu, Zhang, Dongke
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.05.2014; Elsevier
• Subjects: Applied sciences; Ash; Ashes; Biomass; Co-firing; Coal; Combustion of heterogeneous mixtures. Incineration; Combustion. Flame; Deposition; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Sawdust; Scanning electron microscopy; Sintering; Sintering temperature; Straw; Theoretical studies. Data and constants. Metering; Biomass; Co-firing; Sintering temperature; Deposition; Ash; Co-combustion; Experimental study; Sintering; Coal
• ISSN: 0360-5442
• DOI: 10.1016/j.energy.2014.03.050

In this study ash Ts (sintering temperature) is proposed as an index to evaluate deposition propensity during coal and biomass co-firing. The experiments were carried out in a drop-tube furnace and the resulting ash samples were collected. Ts of the ash samples was measured with a pressure-drop sintering device. The chemical compositions and mineral phase characteristics of the ashes were also analyzed using ICP (inductively coupled plasma), SEM (scanning electron microscope) and XRD (X-ray diffraction), respectively. Ts decreased with increasing the mass ratio of biomass to coal with a non-linear relationship. The straw showed a more significant effect on the ash sintering temperature than the sawdust. The limitation of contents in the fuel blends should be 15% and 50% for straw and sawdust, respectively. SEM analysis indicated that biomass promoted ash deposition by accelerating the formation of neck between ash particles. Transformations of the mineral matter to lower sintering temperatures during co-firing had occurred. •We studied the impact of biomass types and content on ash sintering from co-firing.•The relationship between ash sintering temperature and B:A ratio was established.•The introduction of biomass promoted the ash sintering behavior.•We studied the law for transformation of elemental compositions during co-firing.•Coal–biomass blends should be limited to 15% for straw and 50% for sawdust.