Green solvent systems for anhydrous fabric cleaning: from prediction to performance.

Perchloroethylene (PERC), the predominant solvent used in conventional dry cleaning, poses well-documented health and environmental hazards. In pursuit of safer and more sustainable alternatives, this study systematically evaluates sixteen bio-based green solvents selected based on their environmental impact, toxicity, flammability, and Hansen solubility parameters (HSPs). The efficacy of the solvents for removing a range of representative contaminants, including sebum, blood, cocoa, and wine, was evaluated. Ethyl lactate (EL), dimethyl carbonate (DMC), and γ-terpinene were the most effective, exhibiting strong detergency across various soil types. The theoretical solubility affinity, expressed as the relative energy difference (RED), correlated well with the experimental outcomes for simple, well-defined contaminants but showed limitations for complex or heterogeneous soils. To enhance the cleaning efficacy, binary and ternary solvent blends were formulated. A 1:1 mixture of EL and γ-terpinene demonstrated the most balanced and effective cleaning efficacy for both hydrophilic and lipophilic stains. Although mixtures with high γ-terpinene ratios were more effective for cleaning fat-soluble soils, the efficacy for removing water-soluble contaminants was reduced. These findings highlight the predictive utility and limitations of HSPs and underscore the need for integrating theoretical modeling with empirical validation in developing broad-spectrum, sustainable dry-cleaning systems.