European Commission logo
English English
CORDIS - EU research results

Micro-scale inhomogeneities in compressed systems and their impact onto the PROCESS- functioning-chain and the PRODUCT-characteristics

Project description

Improving the efficiency of compressed fluid systems

Compressed fluid systems play a vital role in various industrial processes, contributing to overall efficiency. However, these systems often encounter challenges related to inhomogeneities that can negatively impact the entire operational chain. These inhomogeneities arise due to high-pressure techniques with diffusivities smaller than kinematic viscosity, resulting in unwanted variations during the mixing process. To address this issue, the EU-funded Inhomogeneities project aims to develop an innovative non-invasive Raman spectroscopic solution. This cutting-edge technology will enable users to analyse processes for inhomogeneities, facilitating effective monitoring and preventing critical issues. By improving the efficiency of compressed fluid systems and reducing waste, this project will drive significant advancements in industrial operations.


Compressed fluid systems handled in high pressure processes feature diffusivities smaller than the kinematic viscosity. Therefore during mixing the lifetime of micro(µ)-scale(s) inhomogeneities exceeds that one of macro(m)-scale(s) inhomogeneities. Thus m-s homogeneous systems can still exhibit µ-s inhomogeneities. They affect the functioning-chain of processes, e.g. reactions and phase-transitions or –separations, which themselves also take place on a sub-macro-scale.
Therefore it will be analyzed in situ how µ-s inhomogeneities influence the functioning chain of the particle generation (supercritical antisolvent technology), the reaction (high pressure combustion), and the phase-separation or phase-transition mechanisms (surfactant-free CO2-based micro-emulsions and gas hydrates) and to which extend these inhomogeneities are responsible for the characteristics of the product, such as unfavourable size distributions of particulate products and/or pollutant emissions.
On this purpose the here proposed and self-developed non-invasive and in situ Raman spectroscopic technique considers the INTENSITY-ratios of Raman signals to analyze the m-s composition and the SIGNATURE of the OH stretch vibration Raman signal of water (or alcohols) to analyze the µ-s composition of fluid mixtures. The SIGNATURE of the OH stretch vibration Raman signal is influenced by the development of the hydrogen bonds -an intermolecular interaction- and thus provides the µ-s composition, though the probe volume of the Raman sensor is m-s. The signal-INTENSITY-ratio and signal-SIGNATURE are extracted both from one and the same “m-s” Raman spectrum of the mixture. This allows the comparison of the degree of mixing on m-s and µ-s simultaneously, and enables the analysis of whether a system at any instance of mixing (instance of the onset of a reaction or a phase transition or –separation) has reached the favourable µ-s homogeneity, which would result in homogeneous and uniform products.

Host institution

Net EU contribution
€ 1 058 886,76
09599 Freiberg

See on map

Sachsen Chemnitz Mittelsachsen
Activity type
Higher or Secondary Education Establishments
Total cost
€ 1 058 886,76

Beneficiaries (2)