Chlorine release during low-temperature pyrolysis of olive residue

doi:10.11949/j.issn.0438-1157.20180176

Abstract

Abstract:

Biomass direct combustion is the main way of biomass energy utilization. Chlorine plays an important role in boiler slagging and corrosion during the combustion of high-chlorine biomass. Low-temperature pyrolysis could make chlorine release and get the low chlorine content biomass. We assessed the effect of the low-temperature pyrolysis intensity on the chlorine content of residual biomass and of the released gaseous species. For this purpose, olive residue was subjected to low-temperature pyrolysis (mild pyrolysis) at furnace temperatures, in the range of 250-400℃ in an inert nitrogen atmosphere. The major chlorinated species in the evolving pyrolysis gas (torgas) were identified as HCl and CH₃Cl, and quantified. HCl and CH₃Cl will compete Cl which is released during biomass low-temperature pyrolysis and low temperature will promote the conversion of Cl to CH₃Cl. When the temperature is below 350℃, CH₃Cl is the main product of Cl release and when the temperature arrives at 400℃, HCl will replace CH₃Cl to become the main product during low-temperature pyrolysis.

Key words: biomass, biofuel, low-temperature pyrolysis, chlorine release, HCl, CH₃Cl

摘要：

生物质直燃是生物质能利用的主要方式，而含氯化合物的释放则影响了生物质锅炉的结渣与腐蚀。低温热解作为一种有效的预处理手段可以解决由氯化物导致的锅炉结渣、腐蚀问题。利用水平管式炉试验系统，测量了不同热解温度下橄榄废弃物HCl、CH₃Cl等含氯物质的释放情况，分析了不同热解温度下上述污染物的释放规律。通过分析发现：HCl和CH₃Cl是生物质热解过程中氯的主要析出产物，热解温度的升高有助于氯等元素分别向HCl和CH₃Cl的转化，低温热解条件下氯的释放主要以CH₃Cl为主，随着温度的升高，二者的差距逐渐减小，当温度达到400℃时，HCl取代CH₃Cl成为生物质热解过程中主要的含氯气态产物。

关键词: 生物质, 生物燃料, 低温热解, 氯释放, HCl, CH₃Cl

CLC Number:

XIE Min, CHENG Jian, CHEN Gang, ZHANG Lei, REN Xiaohan. Chlorine release during low-temperature pyrolysis of olive residue[J]. CIESC Journal, 2018, 69(8): 3693-3700.

谢敏, 程健, 陈刚, 张蕾, 任霄汉. 橄榄废弃物低温热解过程中氯的析出规律[J]. 化工学报, 2018, 69(8): 3693-3700.

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