一种改进的LDF模型及其在活性炭吸附中的应用

以固相表面扩散模型为基础，研究了活性炭在不同吸附质浓度下单颗粒的吸附速率与吸附量之间的关系，以及颗粒内浓度分布随时间的变化过程。结合文献对LDF模型的假设，认为吸附初期对吸附剂颗粒内浓度分布做抛物线假设误差较大，吸附初期颗粒表面浓度分布梯度偏低，使得吸附速率降低，并提出了改进后的LDF模型，最后结合固相表面扩散模型和活性炭颗粒吸附SO₂固定床穿透实验曲线进行了验证。结果表明，采用改进后的LDF模型作为推动力方程的穿透曲线模型能够更加准确地描述实验过程。本文的研究结果能够为活性炭吸附过程提供理论依据和模型参考。

A new modified linear driving force model applied to activated carbon adsorption

The relationship between adsorption rate and adsorbate quantity of a single particle, and the adsorbate concentration distribution changing with time inside the particle were studied based on the solid surface diffusion model. Referring to the assumption of LDF in literature, it was found that assuming a parabola distribution of adsorbate concentration inside the particle at the initial time was not suitable, because it caused a lower gradient of particle concentration distribution on the particle surface, and also a lower adsorption rate. A new improved LDF model was put forward, and was verified through the experimental curves of SO₂ adsorption on activated carbon. The modified LDF model was more accurate in predictng the breakthrough curves compared with the LDF model.