This work presents a process design for spirulina production, emphasizing circularity. It analyzes the feasibility of cultivating spirulina in Tumbaco, Ecuador, and proposes a tubular photobioreactor for its culture. A block diagram of the process and a mass balance were developed to quantify the inputs and outputs involved in the production of spirulina powder, from culture to packaging. In addition, a preliminary economic analysis was conducted to evaluate its viability. To apply circularity to the process, the reuse of water and nutrients was discussed. Furthermore, the possibilities of using spirulina as a biosorbent to treat industrial wastewater were explored, transforming a byproduct into an environmental solution. The calculation of costs provided an idea of how economic return would be generated in the future. In contrast, the circular process presented better economic returns, while demonstrating technical viability.

This research investigated the effect of the synthesis conditions on the adsorption capacity of hydrochar (HC) derived from Rosa rubiginosa stems via hydrothermal carbonization. HC samples were prepared at 180, 200 and 220 °C using masses with three different raw-material-to-water ratios (i.e., 5, 7.5 and 10 g of biomass in 80 mL of water), obtaining yields between 43 and 57%. The point of zero charge (PZC) of all samples was determined, obtaining the highest value (5.36) for the sample prepared at 180 °C using 5 g of biomass: 80 mL water ratio (HC5_180). This sample exhibited a crystallinity index value (I_D/I_G, determined by Raman Spectroscopy) of 1.73, which is indicative of a higher degree of structural disorder, related to a greater presence of defects generated by surface functional groups, which, in turn, was identified by infrared spectroscopy. Adsorption tests were conducted using methylene blue (MB), achieving 76.3% removal at an initial concentration of 2.5 mg/L. Adsorption isotherms were also obtained for each HC type, which were fitted to the Langmuir and Freundlich models to elucidate the adsorption mechanism, while kinetic studies were performed on the HC5_180 sample. The findings demonstrate that HC adsorption capacity is governed by the distribution and type of surface functional groups. Thus, the valorization of floral industry by-products into biosorbents, as HC, promotes the circular economy, converting operational waste into a sustainable raw material with added commercial value.

The objective of this study was to develop a strategy for designing a phenolic resin (floral foam) production plant to meet the existing demand in the country, using the PRO II simulation software. For this purpose, the design needs were identified through block diagrams (BDF) and process flow diagrams (PFD), considering the involved unit operations. Additionally, a batch reactor was presented, designed to achieve high conversion in the production of floral foam, according to the reaction for obtaining resol-type floral foam. For this, the volume value was considered, as well as the optimal operating conditions, including pressure and temperature, through a sensitivity analysis. The results were verified by calculating mass and energy balances, using the demand for floral foam, which was approximately 143 tons annually, obtained from the National Customs Service of Ecuador (Importations) website. This value was used for the calculation of daily production and helped to demonstrate the validity of the simulation. The simulated value was 63.4552 kg/day, compared to the calculated phenolic resin production value of 63.3547 kg/day. This shows the relevance of the study and encourages the generation of research that benefits the creation and development of the petrochemical industry.