Fiber-coupled Raman spectroscopy for efficient vapor-liquid equilibria characterization: RaceVLE

精确的材料特性数据是现代基于模型的工艺工程的基础。缺乏足够的汽液平衡（VLE）数据，是化学工程中的一个主要瓶颈。概括地说，目前的模拟工具往往不准确，而常用的实验方法复杂、繁琐且资源效率低。本项目致力于开发一种新的科学装置，用于通过基于光学激光的拉曼光谱（RS）快速有效地提供多组分汽液平衡数据。平衡是在一个光学可访问的静态平衡单元中形成的，其特征在于非侵入性和远程RS。这种方法提供了各种好处，如我们以前的工作所示。这些优点包括测量时间短、物质消耗最少以及无需物理采样即可获得可靠的数据集。然而，为了将这些技术确立为提供汽液平衡数据的新标准方法，我们认为需要基于我们的原理验证设置进行进一步的开发。具体的设计需要昂贵的光学元件，光学实验室和操作员具有丰富的光学知识来设置和运行实验。这些因素阻碍了这一有前途的技术的广泛应用。该项目的中心目标是降低这些障碍和先决条件，以便为尽可能多的研究人员增加该技术的可及性和价值。我们专注于开发一种紧凑的演示器，为该技术的更广泛分布甚至商业化铺平道路。至于其他设备，实现广泛传播的关键策略是简化、自动化、模块化和可靠性。在本项目中，通过不同的手段针对这四个要素。光学和机械设置将被简化。例如，光纤将取代自由光路，增加鲁棒性，并使其能够在不同的光学激光实验室之外使用。专门设计和优化的信号产生和检测路径的汽液平衡相导致高品质的拉曼光谱，允许精确定量的相组成。测量过程将自动化，包括加载物质的设备，控制平衡过程，并记录和评估拉曼测量结果。由此产生的演示器将用于内部提供VLE数据，例如在DFG的卓越集群，RWTH燃料科学中心（FSC）内。对汽液平衡数据提供感兴趣的工业或学术界的研究和开发部门（见所附的支持信）将受益于我们预期的关于该设备的开源出版物以及将在该项目的最后阶段获得的新汽液平衡数据。

Accurate data on material properties are the basis for modern model-based process engineering. The lack of adequate vapor-liquid equilibria (VLE) data, represents a major bottle-neck in chemical engineering. To put the reasons in a nutshell: current simulation tools are often inaccurate, while common experimental methods are complex, cumbersome, and resource-inefficient.This project is dedicated to the development of a new scientific device for the rapid and efficient provision of multi-component VLE data by optical laser-based Raman spectroscopy (RS). Equilibria are formed in an optically accessible static equilibrium cell and are characterized non-intrusively and remotely by RS. This approach offers various benefits, as shown in our previous works. These benefits include short measurement times, minimal substance consumption, and access to reliable datasets without physical sampling.However, to establish the techniques as the new standard method for VLE data provision, we see the need for further developments based on our proof-of-principle setup. The specific design requires expensive optical components, optical laboratories, and operators with profound knowledge on optics to set up and run the experiments. These factors hamper the widespread application of this promising technique.The central goal of this project is to lower these barriers and prerequisites in order to increase the accessibility and value of the technology for as many researchers as possible. We focus on developing a compact demonstrator to pave the road for broader distribution or even commercialization of the technique. As for other devices, the key strategies for enabling widespread dissemination are simplification, automation, modularization, and reliability. These four elements are targeted through different means within this project. The optical as well as the mechanical setup, will be streamlined. As an example, fibers will substitute free light paths, increasing the robustness and enabling the use outside of distinct optical laser laboratories. Specifically designed and optimized signal generation and detection paths for the VLE phases lead to high-quality Raman spectra that allow precise quantification of the phase compositions. The measurement procedure will be automated, including loading the device with substances, controlling the equilibration process, and recording and evaluating the Raman measurements.The resulting demonstrator will be used for the in-house provision of VLE-data, e.g. within our DFG cluster of excellence, the RWTH fuel science center (FSC). Research and development departments in industry or academia interested in VLE data provision (see attached letter of support) will benefit from our anticipated open-source publications on the apparatus as well as on new VLE data that will be acquired within the final phase of this project.