Green algae are a sustainable source of biopolymers for the global demand due to their high photosynthetic efficiency. This article describes the extraction of cellulose from plant systems represented by Ulva lactuca species. In order to extract various substances, algae were finely ground with the help of solvents (liquid media). This was carried out to achieve the necessary conditions that help reduce the resistance this phase shows in regard to the transport and transfer of the species being extracted. The highest yield of extracted cellulose (20,944%) was obtained for the following factors: S/L = 1/20; conc. ethanol = 90%, conc. salts = 4 g/L. Hydrogel membranes are a unique class of macromolecular networks that contain a large fraction of aqueous solvent within their structure. With the cellulose extracted from algae, we obtained membranes which underwent the process of swelling in liquid media (ethyl alcohol) of different concentrations. The swelling of biocellulose membranes in alcoholic solutions of high concentrations was investigated. It was observed that the process of absorption of the alcoholic solution by the membrane occurred rapidly in the first part. After stabilization, the membranes continued to absorb at a slower rate until stabilization or saturation concentration was reached.

Heterogeneous catalysts, basic, acidic or bifunctional, can catalyze transesterification reactions where the raw material has a significant content of FFA fatty acids, such as used cooking oils or other lipid-based residues, which do not have the purity required for homogeneous catalysis, in which case the purity of the triglycerides above 99.5% is the first condition for the initiation of the reaction, to avoid saponification. In this work, a green supported catalyst was developed, using bacterial cellulose as catalytic support and biodegradable superbase as a chemical compound, for transesterification reaction to obtain alkyl esters, yielding over 99% of its content at 70 °C temperature and 7.5% catalyst loading (1.5/20 w/w catalyst:oil). A Plackett-–Burman design was used for screening experiments to explore the main effect in terms of catalytic activity and performance of the triglyceride conversion reaction.

Green catalysts used in the transesterification reaction of biodiesel must have biodegradability and non-toxicity as their main characteristics, being thus friendly to the environment, since they perform in processes in which the content of CO₂, which is increasing from year to year, should be reduced. As a consequence, their manufacture can be extremely rigorous. This work presents the two-step construction, synthesis, and deposition of such a green heterogeneous catalyst and its testing in the catalysis of the transesterification of triglycerides with methanol, resulting in methyl esters. A CSTR-type reactor was used to perform transesterification, and the biodiesel yields obtained had values in the range of 91.7–95.7%, using 2, 3, and 4 g/g catalyst to oil, under conditions like those for obtaining commercial biodiesel in homogeneous catalysis, i.e., a 65 °C process temperature and a 4:1, 5:1 or 6:1 methanol-to-oil molar ratio.

The aim of this study was to improve the quality of a vegetable oil, having in view its use as a quenchant for metallic parts in aircrafts. A process of pyrolysis under vacuum was applied to obtain a bio-oil with reduced viscosity and good quenching properties. Preliminarily, the rapeseed oil was fast pyrolyzed at temperature in the range of 300–375 °C and absolute pressure of 1 μbar. Some results such as viscosity and yields of bio-oil were obtained with a narrowing of the temperature range between 300–320 °C, for further processing. Quenching tests with bio-oils on stainless steel 25CD4 showed cooling curves closer to those of the standard mineral oil (Castrol Iloquench^TM 1), by comparing them with unprocessed vegetable oil. The hardness of the steel after treatment rose from 29–30 HRC to 43–45 HRC, in accordance with requirements (35–45 HRC). Therefore, the conclusion is that bio-oils obtained by pyrolysis under vacuum are good quenchant proceeds from this study.