At the industrial level, separation of a variety of mixtures is predominantly carried out by thermally driven processes such as distillation. Nevertheless, the current literature seems to suggest that much is to be gained by replacing these processes with alternative non-thermal methods, which will potentially require a fraction of the energy used by distillation. This is primarily due to the widespread perception that thermal separation processes, particularly those that involve vaporization, are highly energy intensive. However, this belief is not well founded, because it is based on extrapolation from comparisons in the literature, many of which make ad-hoc assumptions and result in incorrect conclusions. Our analysis shows that this confusion arises because the processes utilize different types of energy: heat and electricity. Here, we present a consistent framework that enables a fair comparison between different processes that consume different forms of energies. Using this framework, we refute the general perception that thermal separation processes are inherently the most energy intensive and conclusively show through the examples of two challenging mixtures constituting components with low relative volatilities, that distillation processes, when run properly, can consume remarkably lower fuel than non-thermal membrane alternatives, which have often been touted as more energy efficient.

在工业水平上，各种混合物的分离主要通过热驱动的方法例如蒸馏来进行。然而，目前的文献似乎表明，用替代的非热方法代替这些方法将获得很多好处，这可能需要蒸馏所用能量的一小部分。这主要是由于人们普遍认为，热分离过程，特别是涉及汽化的过程，是高度能源密集型的。但是，这种信念并不是很好的根据，因为它是基于文献比较中的推论得出的，其中许多是临时性的假设，并且得出错误的结论。我们的分析表明，这种混乱之所以出现，是因为流程使用了不同类型的能源：热和电。这里，我们提出了一个一致的框架，可以对消耗不同形式能量的不同过程进行公平的比较。使用此框架，我们驳斥了一般的认识，即热分离过程本质上是最耗能的过程，并通过构成具有较低相对挥发度的两种具有挑战性的混合物的示例来明确表明，蒸馏过程在正确运行时所消耗的燃料比非热膜替代品，通常被吹捧为更节能。