Biomass-based pyrolytic polygeneration system on cotton stalk pyrolysis: Influence of temperature

Conventional and microwave-assisted pyrolysis of biomass under different heating rates

“…Increasing the power from 600 to 1200 W, thereby essentially increasing the heating rate, shifts the appearance of CO 2 and CO from below 60 °C to around 175 °C. As discussed above, the release of CH 4 and H 2 mainly occurs at higher reaction temperature (e.g. conventional pyrolysis at 310 °C shows negligible production of CH 4 and H 2 , Figure 1).…”

“…As discussed above, the release of CH 4 and H 2 mainly occurs at higher reaction temperature (e.g. conventional pyrolysis at 310 °C shows negligible production of CH 4 and H 2 , Figure 1). Herein, for the microwave pyrolysis, production of CH 4 can be clearly observed when the microwave power was increased to 900 or 1200 W. Therefore, release of CH 4 gas can be significantly promoted with higher microwave power due to promoted interactions of biomass molecules, while the reaction temperature was kept constant.…”

“…The gaseous pyrolysis products were passed through an air cooled condenser and a dry ice cooled condenser to trap the product liquids. Non-condensed gases were passed into an on-line gas analyser allowing for the determination of CO, CO 2 , H 2 and CH 4 . N 2 was used as the carrier gas with a flow rate of 80 ml min -1 .…”

“…Given the lower temperature at which these gases appear, they are likely to derive from the hemicellulose fraction, which is normally decomposed at lower temperature compared with other biomass components [24][25][26]. The formation of CH 4 and H 2 is linked to higher pyrolysis temperatures, exceeding markedly those needed for CO 2 /CO production. This is consistent with the observations by Yang et al [27]; they suggested that the CH 4 /H 2 formation relates to secondary or primary reactions with a high activation energy.…”

“…The advantage of pyrolysis is that the yield of end-products can be altered depending on the process conditions; the temperature of pyrolysis and the heating rate are known to have most influence [3][4][5][6]. High char yields are obtained from biomass via slow heating rates to moderate temperatures of ~ 400 °C.…”