Biomass

The aviation industry faces increasing pressure to reduce its environmental impact and achieve net-zero emissions by 2050. In this context, sustainable aviation fuels (SAF) have emerged as a critical alternative to conventional jet fuels. This study provides a comprehensive analysis of SAF technologies from a chemical engineering perspective, highlighting key production routes, technological maturity levels, and implementation challenges. A bibliometric analysis using the Scopus database and VOSviewer software was conducted to identify research trends and thematic clusters in SAF literature. The analysis reveals a growing interest in advanced biofuels and physicochemical conversion technologies, particularly those supported by catalytic and thermochemical processes. Certified and emerging SAF pathways were examined with respect to their process efficiency, feedstock availability, and scalability. Additionally, the study explores the potential of Latin America as a strategic region for SAF development, considering its abundant biomass resources and ongoing pilot projects. This critical and holistic analysis aims to support researchers, engineers, and policymakers in understanding the current state and future directions of SAF technologies within the framework of chemical process design and optimization. Overall, Hydroprocessed Esters and Fatty Acids Synthetic Paraffinic Kerosene (HEFA-SPK) and Fischer–Tropsch Synthetic Paraffinic Kerosene (FT-SPK) are identified as the most mature and widely deployed SAF production routes, whereas Alcohol to Jet (ATJ), Synthesized Iso-Paraffins (SIP), and Direct Sugar to Hydrocarbons (DSHC) remain at earlier technological stages despite their long-term potential for feedstock diversification and reduced environmental impacts. The analysis also underscores Latin America, where abundant biomass resources, consolidated agro-industrial systems, and emerging SAF research initiatives create favorable conditions for future development and deployment.

Climate change and the impacts related to nonbiodegradable synthetic materials highlight the need for sustainable alternatives. Biopolymers from renewable sources show great potential for producing hydrogels, which are three-dimensionally crosslinked materials with high water absorption. In this work, super-absorbent biodegradable hydrogels were produced via single-step reactive extrusion using mixtures of starch, gelatin, cellulose, and xanthan gum, with glycerol as a plasticizer, and citric acid as a crosslinking agent. Pelleted hydrogels were obtained with water absorption between 290% and 363%. Reactive extrusion promoted the formation of new ester and amide bonds, confirmed by FT-IR. Citric acid was effective as a crosslinker, and higher citric acid content (3%) produced samples with greater swelling, supported by the porous internal structure observed. Preliminary agricultural tests showed that the formulation with the highest citric acid content, when added to soil at 5%, significantly increased water-holding capacity and resulted in the highest germination rate of maize seeds. Overall, the extrusion process proved efficient, scalable, and environmentally friendly for producing biodegradable hydrogels for agricultural applications.

Egg products are a convenient and safe form of eggs, possessing valuable nutritional and functional properties. The egg processing industry is responsible for the enormous amounts of biomass in the form of animal by-products (ABPs). According to EU legislation, the ABPs are under strict control from the formation to the disposal of biomass, as they carry a risk to the ecosystem and public health. For this reason, restrictions have been introduced on their use after disposal, ranging from bioactive applications in medical, cosmetic, and pharmaceutical products, as well as feed. The shells are subject to special conditions for processing and use. The by-products of egg breaking are divided into solid (eggshells and eggshell membranes) and liquid (technical albumen) by-products. The biological value is determined by the composition, which varies significantly across the by-products. In the context of the circular economy, all egg by-products contain valuable substances that can be used in food and non-food industries. First, eggshells are the leading by-product, composing 95% of the inorganic substance calcium carbonate, which, after processing, can be used in agriculture, food and feed industries, and medicine. Second, there is a liquid by-product containing proteins from the egg white and a small part of fats from the yolk. Literature data on this by-product are scarce, but there is information about its use as a feed additive, while the extracted and purified proteins can be useful in pharmacy. Egg membranes constitute only 1% of the egg mass, but humanity has long known about the benefits of collagen, keratin, and glycosaminoglycans, including hyaluronic acid, which compose this material. The processed membranes can be used as a food additive, in cosmetics, medicine, or pharmacy, just like other egg by-products mentioned above. This literature review focuses on the possible methods and techniques for processing by-products and their potential application. The literature sources in this review have been selected according to their scientific and practical applicability. The utilization of these by-products not only reduces the impact on the environment but also facilitates the creation of value-added materials.