Cassava processing produces by-products such as brown bark, between bark, disposal, bran, fiber and bagasse. Cassava bagasse is characterized as a source of starch that can be converted into sugars to obtain biofuels. The objective of this work was to produce ethanol from this cassava processing residue and to evaluate its contribution potential in the Brazilian energy matrix. Cassava processing residues were obtained from four different starch manufacturers in Brazil. Analysis of the chemical compositions of these samples provided the content of starch, sugar, crude grease, moisture, ash and also their pH values. For the ethanol process, the samples were submitted to enzymatic hydrolysis using the alpha-amylase and amyloglucosidases enzymes, followed by fermentation and distillation. The samples showed high starch indices, approximately 64% on average. The average yield of ethanol obtained was 30% after treatment of the sample like this. Considering the estimated volume of cassava bagasse in Brazil, it is possible to produce an average of 789 million cubic meters per bagasse, replacing about 24% of the first generation ethanol. Cassava bagasse can be considered an interesting biomass for the production of biofuels, contributing to the expansion of the energy matrix.

Natural products can be used as complements or as alternatives to synthetic drugs. Eugenia uniflora and Tropaeolum majus are natives of Brazil and have antimicrobial, anti-inflammatory, and antioxidant activities. This study aimed to develop a film-forming system (FFS) loaded with plant extracts with the potential for treating microbial infections. E. uniflora and T. majus leaf extracts were prepared and characterized, and the individual and combined antioxidant and antimicrobial activities were evaluated. The FFS was developed with different concentrations of polyvinylpyrrolidone (PVP) and polyvinyl alcohol (PVA) and analyzed for physicochemical characteristics. The combination of extracts showed a superior antioxidant effect compared to the individual extracts, justifying the use of the blend. FFS prepared with 4.5% PVA, 4.5% PVP, 7.81% E. uniflora extract, and 3.90% T. majus extract was adhesive, lacked scale formation, presented good malleability, and had a suitable pH for topical application. In addition, the viscosity at rest was satisfactory for maintaining stability; water solubility was adequate; skin permeation was low; and the antimicrobial effect was superior to that of the individual extracts. Therefore, the developed FFS is promising for the differentiated treatment of skin lesions through topical application.

Background/Objectives: Considering the antioxidant and antimicrobial properties attributed to compounds in Syzygium cumini extract, this research aimed to advance postoperative therapeutic innovations. Specifically, the study assessed the physicochemical properties of a film-forming solution (FFS) incorporated with S. cumini, evaluating its therapeutic potential for postoperative applications. Methods: The S. cumini extract was meticulously characterized to determine its chemical composition, with particular emphasis on the concentration of phenolic compounds. Antioxidant and antimicrobial assays were conducted to assess the extract’s efficacy in these domains. Following this, an FFS containing S. cumini was formulated and evaluated comprehensively for skin adhesion, mechanical and barrier properties, and thermal behavior. Results: The antioxidant and antimicrobial activities of the S. cumini extract demonstrated promising results, indicating its potential utility as an adjunct in postoperative care. The developed FFS exhibited favorable physicochemical properties for topical application, including adequate skin adhesion and appropriate pH levels. Moreover, chemical and thermal analyses confirmed the formulation’s stability and the retention of the extract’s beneficial properties. Conclusions: Overall, the findings suggest that the S. cumini-loaded FFS holds significant potential as a valuable therapeutic tool for post-surgical management.

Purpose: The purpose of this paper is to investigate straw modification by chemical degradation generated by two forms of pretreatment, using citric acid in an autoclave and urea solution with sodium hydroxide at low temperature. Design/methodology/approach: The material was digested and compared in biodigester reactors lined with natural straw, straw pretreated with citric acid, straw pretreated with urea and NaOH, and straw subjected to both the pretreatments. The amount of straw has been delimited to 0, 2.5, 5, 7.5 and 10 percent v/v, and used 20 percent v/v inoculum in all reactors, consisting of 30 percent v/v poultry litter and 70 percent swine wastewater (SW). The experiment was conducted in an incubator kept in mesophilic conditions (35°C). Findings: The results indicate significant change in the studied material, with degradation of lignin as well as hemicellulose and cellulose exposed to further hydrolysis. Spectrophotometric methods were used for monitoring degradation. These methods were efficient in monitoring changes caused by the treatments. When the proposed pretreatments are applied to sugarcane straw, there is a significant gain in biogas production (L g VSR⁻¹). The most appropriate rates for higher methane production in the pretreatments are 2.5 and 5 percent straw-SW. The best results for the anaerobic digestion of sugarcane straw were obtained by pretreating it with citric acid. Originality/value: This paper shows a new use for the sugarcane straw waste after being pretreated with acid or base for the coproduction of biogas.

Through a review of the bibliographic base was identified the potential and difficulties of using biofuels based on babassu culture for use as aviation biofuel. Babassu palm is one of the most important crops for family farming in the north and northeast of Brazil due to its vast use potential. From babassu oil, by transesterification, good quality biodiesel can be obtained. However, it does not have the properties necessary to be used as aviation biofuel. Researches with biofuels from this culture and cultures with a similar organic profile were analyzed pointing out the feasibility of these biofuels as a mixture in aviation kerosene, nevertheless, these biofuels present several problems when used alone. Among the physical-chemical properties analyzed, the freezing point was a critical factor for not using these biofuels. This review points out the best results to improve the physicochemical properties of babassu biofuels to use as aviation fuel and present an important social factor to this palm uses.

In this study, we investigate the dual-fuel operation of compression ignition engines using biodiesel at varying concentrations in combination with biogas, with and without hydrogen enrichment. A response surface methodology, based on a central composite experimental design was employed to optimize energy efficiency and minimize pollutant emissions. The partial substitution of diesel with gaseous fuel substantially reduces the specific fuel consumption, achieving a maximum decrease of 21% compared with conventional diesel operation. Enriching biogas with hydrogen, accounting for 13.3% of the total flow rate, increases the thermal efficiency by 0.8%, compensating for the low calorific value and reduced volumetric efficiency of biogas. Variations in biodiesel concentration exhibits a nonlinear effect, yielding an additional average efficiency gain of 0.4%. Regarding emissions, the addition of hydrogen to biogas contributes to an average reduction of 5% in carbon monoxide emissions compared to the standard dual-fuel operation. However, dual-fuel operation leads to higher unburned hydrocarbon emissions relative to neat diesel; hydrogen enrichment mitigates this drawback by reducing hydrocarbon emissions by 4.1%. Although NO_x emissions increase by an average of 26.6% with hydrogen addition, dual-fuel strategies achieve NO_x reductions of 11.5% (hydrogen-enriched mode) and 33.3% (pure biogas mode) relative to diesel-only operation. Furthermore, the application of response surface methodology is robust and reliable, with experimental validation showing errors of 0.55–8.66% and an overall uncertainty of 4.84%.