Combustion characteristics and combustionkinetics of agriculture biomass

Abstract: In order to efficiently utilize agricultural biomass, thermogravimetry experimentation analysis of corn stalks, corn cobs, straw, lychee bar, and longan sticks and its mixed fuel was performed by using the TG-DTG-DSC (Thermogravimetric-Differential Thermogravimetric-Differential Scanning Calorimetry) thermal analysis technology. The combustible characteristics, ignition characteristics, burnout characteristics and synthetic combustion characteristics were investigated, and the combustion kinetics parameters were identified. The results show that the early burning DTG curves of corn stalks and corn cob have two peaks and three peaks, respectively, and the burning DTG curves of straw, longan sticks, and lychee strip each have only one peak. The mixed fuels prophase similar combustion characteristics of corn stalks, straw, and lychee bar show that the three fuels are suitable co-combustion. DSC curves of corn stalks S1 and straw S3 both have one endothermic peak late in the combustion, and the post-combustion needs to absorb more heat in order to maintain its combustion, which indicates that herbaceous biomass post-combustion stability is poor and not suitable for separate combustion. The DSC curve characteristics of wood-based biomass show that wood-based biomass has higher post-combustion stability. The combustible characteristics index and ignition characteristics index of corn stalks are both the largest, and their ignition temperature is the lowest, resulting in excellent pre-combustion performance. The burnout characteristic index of lychee bar is the largest and its burnout rate is the best, but its early combustion characteristics are not easy to catch fire and burn. The synthetic combustion characteristics of corncob are the best. The low-temperature phase of the reaction order is about 1.0-1.2, the high temperature phase of the reaction order is approximately 0.5-0.8, and the corresponding reaction activation energy is larger at the low temperature phase than that at the high temperature phase. The early biomass burning is a homogeneous fire and the late biomass burning belongs to a multiphase fire. The late stability of pure burning straw biomass is bad, but adding straw biomass with wood biomass is conducive to its pre-combustion of mixed fuels. The study results can provide guidance for the combustion and utilization of agricultural biomass.