Developing an integrated supercritical fluid biorefinery for the processing of grains

Integrated supercritical fluid extraction of essential oils

Supercritical fluid extraction (SFE) stands out as an incredibly efficient, environmentally conscious, and fast method for obtaining essential oils (EOs) from plants. These EOs are abundant in aromatic compounds that play a crucial role in various industries such as food, fragrances, cosmetics, perfumery, pharmaceuticals, and healthcare. While there is a wealth of existing literature on using supercritical fluids for extracting plant essential oils, there's still much to explore in terms of combining different techniques to enhance the SFE process. This comprehensive review presents a sophisticated framework that merges SFE with EO extraction methods. This inclusive categorization encompasses a range of methods, including the integration of pressurized liquid processes, ultrasound assistance, steam distillation integration, microfluidic techniques, enzyme integration, adsorbent facilitation, supercritical antisolvent treatments, molecular distillation, microwave assistance, milling process and mechanical pressing integration. Throughout this in-depth exploration, we not only elucidate these combined techniques but also engage in a thoughtful discussion about the challenges they entail and the array of opportunities they offer within the realm of SFE for EOs. By dissecting these complexities, our objective is to tackle the current challenges associated with enhancing SFE for commercial purposes. This endeavor will not only streamline the production of premium-grade essential oils with improved safety measures but also pave the way for novel applications in various fields.

The application of green solvent in a biorefinery using lignocellulosic biomass as a feedstock

The high dependence on crude oil for energy utilization leads to a necessity of finding alternative sustainable resources. Solvents are often employed in valorizing the biomass into bioproducts and other value-added chemicals during treatment stages. Unfortunately, despite the effectiveness of conventional solvents, hindrances such as expensive solvents, unfavourable environmental ramifications, and complicated downstream separation systems often occur. Therefore, the scientific community has been actively investigating more cost-effective, environmentally friendly alternatives and possess the excellent dissolving capability for biomass processing. Generally, 'green' solvents are attractive due to their low toxicity, economic value, and biodegradability. Nonetheless, green solvents are not without disadvantages due to their complicated product recovery, recyclability, and high operational cost. This review summarizes and evaluates the recent contributions, including potential advantages, challenges, and drawbacks of green solvents, namely ionic liquids, deep eutectic solvents, water, biomass-derived solvents and carbon dioxide in transforming the lignocellulosic biomass into high-value products. Moreover, research opportunities for future developments and potential upscale implementation of green solvents are also critically discussed.

Valorization of byproducts from tropical fruits: A review, Part 2: Applications, economic, and environmental aspects of biorefinery via supercritical fluid extraction

The global trade of tropical fruits is expected to increase significantly in the coming years. In 2018, the production was approximately 100 million tones, an increase of 3.3% compared to the previous year. Nevertheless, according to the Food and Agricultural Organization, every year one-third of the food produced in the world for human consumption is lost or wasted. More specifically, around 45% of the fruits, constituted mainly by peels, seeds, and pulps after juice extraction, are discarded mainly in the agricultural and processing steps. Therefore, decreasing and/or using these byproducts, which are often rich in bioactive components, have become an important focus for both the scientific community and the fruit processing industry. In this line, supercritical fluid extraction (SFE) technology is expected to play a significant role in the valorization of these byproducts. This review presents the concepts of a tropical fruit biorefinery using supercritical CO₂ extraction and the potential applications of the isolated fractions. There is a specific focus on the extraction of bioactive compounds, that is, carotenoids and phenolics, but also oils and other valuable molecules. Moreover, the techno-economic and environmental performance is assessed. Overall, the biorefinery of tropical fruits via SFE provides new opportunities for development of food and pharmaceutical products with improved economic and environmental performance.

Valorization of Tropical Biomass Waste by Supercritical Fluid Extraction Technology

The inception of sustainable and cleaner extraction technology has paved the way for the innovative development of nonconventional extractions, such as supercritical fluid extraction, apart from conventional extraction counterparts. The concept of biomass waste-to-wealth for the conversion of biomass waste or by-products into value-added products for diversified applications had piqued the prominent interest of researchers and industry players, especially with the abundance of biomass resources readily available in tropical regions that have yet to be tapped into to reach their full potential. In this paper, a critical review of the developments of supercritical fluid technology from its initial inception up to commercialized scalability, including its limitations, extraction of potential tropical biomass wastes for various types of applications, such as biopesticides, bio-repellents, phenolics, and lipids for biofuel, and its role in circular bioeconomy and sustainable development approaches, are discussed in detail.

Experimental solubilities of two lipid derivatives in supercritical carbon dioxide and new correlations based on activity coefficient models

Solubilities of 10-undecen-1-ol and geranyl butyrate were determined and correlated based on new models by combinations of solution/association theories.