The pulp and paper industry is one of the biggest industry sectors worldwide, whose market growth is expected to reach 370.12 billion USD by 2028. However, as a water-intensive process, the pulp and paper production generate huge volumes of contaminated effluents, some of which contain dissolved high-value chemical compounds, such as lignin, hemicellulose, or carboxylic acids. These compounds can be recovered using membrane operations. Thus, membrane operations represent a method to valorize effluents and byproducts from this industry sector and narrow the gap between biorefinery models and the pulp and paper production as an integrated biorefinery. The present review reviews the state-of-the-art-research and the state-of-the-art applications of membrane operations in the pulp and paper industry.

High quantities of biomass produced in greenhouses create environmental problems, as this side stream and its downgraded products are not further used in the production cycle. The aim of our research was the identification and semi-quantification of molecules extracted from vegetative tomato plant residues with sustainable green alternative solvents using vacuum-assisted soxhlet and solid-liquid extraction to evaluate the possibilities for high-value applications. To identify compounds, GC-MS analysis, and the Folin-Cioalteau method was used. In sum, 285 different compounds have been assigned to 383 detected peaks using GC-MS analysis. The solvents 2-MTHF and ethyl acetate, compared to ethanol and hexane, provided better results with a maximum number of 99 ± 8.83 compounds, a maximum total concentration of 5,894.82 ± 586.48 and 3,363.02 ± 71.14 mg NEQ kgdw-1 and a total phenolic content of 2,143.25 ± 155.17 and 1,605.92 ± 66.46 mg GAE kgdw-1, respectively. With 781.2 ± 112.66 and 718.25 ± 54.89 mg NEQ kgdw-1 the compound neophytadiene was the most common terpene in ethyl acetate and 2-MTHF extracts, respectively. It can be concluded that vegetative tomato plant residues contain a high variety of bioactive molecules. Green solvents, such as 2-MTHF and ethyl acetate, enhance the extraction of these molecules from the solid matrix.