In this work, we simulated the heat transfer in a two-vessel (1-m, length-to-diameter ratio of 4) industrial plant to assess the effect of the temperature gradients formed during the reconditioning stage on the extraction curves. We simulated the extraction of 1-mm particles using 5 mm/s of CO at 48 MPa and 40 °C (case with an imposed temperature gradient) or 60 °C (case with temperature gradients from the reconditioning stage), with the service fluid at 60 °C. The results of these non-isothermal extractions were compared with those obtained in representative isothermal cases. The temperature gradients slightly affected the cumulative extraction curves in non-isothermal cases. We considered the presence of a basket containing the solid substrate. We also changed the superficial CO velocity to 3 or 10 mm/s and the particle size to 0.50 or 1.25 mm to compare the extraction curves. The effects of the basket and the changes in superficial CO velocity and particle size were minor. We simulated a limit case with higher temperature and pressure (80 °C and 70 MPa), where the extraction time was extremely short (10 min) and more significant temperature gradients were formed during the reconditioning stage. We observed more significant differences at this extreme extraction condition than when using an isothermal process at the required extraction temperature.

中文翻译：

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传热对超临界二氧化碳萃取过程的加压、萃取和减压阶段的影响。 2. 两艘工业厂房的模拟


在这项工作中，我们模拟了两个容器（1 米，长径比为 4）工业厂房中的传热，以评估修复阶段形成的温度梯度对萃取曲线的影响。我们使用工作液，在 48 MPa 和 40 °C（具有强加温度梯度的情况）或 60 °C（具有来自修复阶段的温度梯度的情况）下，模拟使用 5 mm/s CO 萃取 1 mm 颗粒在60°C。将这些非等温萃取的结果与代表性等温情况下获得的结果进行比较。在非等温情况下，温度梯度轻微影响累积提取曲线。我们考虑了含有固体基质的篮子的存在。我们还将 CO 表面速度更改为 3 或 10 mm/s，并将颗粒尺寸更改为 0.50 或 1.25 mm，以比较提取曲线。篮子的影响以及表观 CO 速度和颗粒尺寸的变化都很小。我们模拟了较高温度和压力（80℃和70MPa）的极限情况，其中萃取时间极短（10分钟），并且在修复阶段形成更显着的温度梯度。我们在这种极端提取条件下观察到比在所需提取温度下使用等温过程时更显着的差异。