去髓和留髓玉米秸秆燃料特性的对比分析

Comparison of properties for corn straw with and without pith

通过对去髓和留髓玉米Zea mays秸秆的化学成分、工业分析、元素分析、低位发热量、热动力学以及灰熔点几个方面的特性做对比,发现留髓玉米秸秆木质素较高,占整秆的27.72%,纤维素较低,占整秆的25.65%。相较于留髓玉米秸秆,去髓玉米杆的纤维素(25.47%)和木质素(21.90%)均低于留髓玉米秸秆;留髓的玉米秸秆的固定碳(13.61%)和低位发热量(16 536 J.g-1)都高于留髓玉米秸秆;同时留髓玉米秸秆的活化能和频率因子也要高于去髓玉米秸秆,但留髓玉米秸秆灰的变形温度(1 173℃)和软化温度(1 258℃)比去髓玉米秸秆低100℃以上。研究表明:玉米整秆相较于去髓玉米秸秆更易燃烧且更适合制作燃料,但需要对燃烧锅炉进行改造,期望能够对玉米秸秆制作燃料作为人造板工厂新能源提供一定理论基础。

To determine if corn（Zea mays） stalks without pith could be used to make pellet fuel,characteristics of corn straw with and without pith,including chemical composition and combustion kinetics parameters, were compared.Results showed that corn stalk burning could be divided into three stages： water evaporation, volatile combustion,and burning of fixed carbon.Corn stalk with pith had higher calorific value（16 536 J·g-1） and combustion kinetics parameter.However,the melting point of corn straw ash with pith was lower.It showed that the deformation temperature of corn straw ash was 1 173 ℃ and the melting point was 1 258 ℃;whereas without pith the deformation temperature was 1 285 ℃ and the melting point was 1 441 ℃. Overall,the results showed that corn straw with pith exhibited higher lignin content than without pith,but a lower cellulose content.Corn straw with pith had lower fixed carbon content,calorific value,activation energy, and frequency factor,but higher ash melting point and softening temperature.Thus,corn straw would be an environmental-friendly fuel,as its low calorific value was similar to bituminous coal with an S content only 1/2-1/3 that of coal,and corn straw with pith seemed more suitable for making pellet fuel,which could be used as a new energy source for a wood-based panel factory.