Reaction kinetics is fundamental for modelling the thermal oxidation of a solid phase, in processes such as dust explosions, combustion or gasification. The methodology followed in this study consists in i) the experimental identification of the reaction mechanisms involved in the explosion of organic powders, ii) the proposal of simplified mechanisms of pyrolysis and oxidation, iii) the implementation of the model to assess the explosion severity of organic dusts. Flash pyrolysis and combustion experiments were carried out on starch (22 μm) and cellulose (53 μm) at temperatures ranging from 973 K to 1173 K. The gases generated were collected and analyzed by gas chromatography. In this paper, a semi-global pyrolysis model was developed for reactive systems with low Damköhler number. It is in good agreement with the experimental data and shows that both carbon monoxide and hydrogen are mainly generated during the pyrolysis of the solid, the generation of the latter compound being greatly promoted at high temperature. A simplified combustion model was also proposed by adding two oxidation reactions of the pyrolysis products. In parallel, flame propagation tests were performed in a semi open tube in order to assess the burning velocity of such compounds. The laminar burning velocity of cellulose was determined to be 21 cm s⁻¹. Finally, this model will be integrated to a predictive model of dust explosions and its validation will be based on experimental data obtained using the 20 L explosion sphere. The explosion severity of cellulose was determined and will be used to develop and adjust the predictive model.

在粉尘爆炸、燃烧或气化等过程中，反应动力学是模拟固相热氧化的基础。本研究采用的方法包括 i) 有机粉末爆炸反应机制的实验鉴定，ii) 热解和氧化的简化机制的提议，iii) 评估爆炸严重程度的模型的实施有机粉尘。在 973 K 至 1173 K 的温度范围内对淀粉 (22 μm) 和纤维素 (53 μm) 进行快速热解和燃烧实验。收集产生的气体并通过气相色谱法进行分析。在本文中，为具有低 Damköhler 数的反应系统开发了一个半全局热解模型。与实验数据吻合较好，表明一氧化碳和氢气均主要在固体热解过程中产生，高温下极大促进了后者化合物的产生。通过添加热解产物的两个氧化反应，还提出了一个简化的燃烧模型。同时，在半开口管中进行火焰传播测试，以评估此类化合物的燃烧速度。纤维素的层流燃烧速度确定为 21 cm s 火焰传播测试在半开管中进行，以评估此类化合物的燃烧速度。纤维素的层流燃烧速度确定为 21 cm s 火焰传播测试在半开管中进行，以评估此类化合物的燃烧速度。纤维素的层流燃烧速度确定为 21 cm s^-1。最后，该模型将集成到粉尘爆炸预测模型中，其验证将基于使用 20 L 爆炸球获得的实验数据。确定了纤维素的爆炸严重程度，并将用于开发和调整预测模型。