Biodiesel is seen as a successor to diesel of petrochemical origin, as it can be used in cycle and stationary engines and be obtained from renewable raw materials. Currently, the biodiesel production process on an industrial scale is mostly carried out through the transesterification reaction, also forming glycerol as a product. Pure glycerol is used in the pharmaceutical, cosmetic, cleaning, food, and other industries. Even presenting numerous applications, studies indicate that there is a saturation of glycerol in the market, which is directly related to the production of biodiesel. This increase causes a commercial devaluation of pure glycerol, making separation and purification processes unfeasible from an economic point of view. Despite the economic unfeasibility of the aforementioned processes, they continue to be carried out due to environmental issues. Faced with the problem presented, this work provides a bibliographical review of works that aimed to use glycerol as a raw material for the production of biofuels, with these processes being carried out mostly via fermentation.

Due to growing worldwide energy demand, the search for diversification of the energy matrix stands out as an important research topic. Bioethanol represents a notable alternative of renewable and environmental-friendly energy sources extracted from biomass, the bioenergy. Thus, the assurance of optimal growth conditions in the fermenter through operational variables manipulation is cardinal for the maximization of the ethanol production process yield. The current work focuses in the determination of optimal control scheme for the fermenter feed rate and batch end-time, evaluating different parametrization profiles, and comparing evolutionary computation techniques, the genetic algorithm (GA) and differential evolution (DE), using a dynamic real-time optimization (DRTO) approach for the in silico ethanol production optimization. The DRTO was able to optimize the reactor feed rate considering disturbances in the process input. Open-loop tests results obtained for the algorithms were superior to several works presented in the literature. The results indicate that the interaction between the intervals of DRTO cycles and parametrization profile is more significant for the GA, both in terms of ethanol productivity and batch time. In general lines, the present work presents a methodology for control and optimization studies applicable to other bioenergy generation systems.

Currently, there is a worldwide concern, not only with the exhaustion of diesel oil, but also with the environmental damages caused by this fuel, from the process of extracting oil to consumption. The emission of the gases from the combustion process of this fuel are harmful to the health of living beings and contribute directly to the worsening of the greenhouse effect. Biodiesel appears in this context as a possible substitute for diesel. Thus, the main objective of this work was to carry out a bibliographical review of the main catalytic processes available in the literature for the production of biodiesel, respectively, the main chemical reactions involved in these processes, being: the esterification and transesterification reaction. Among the catalytic processes, the alkaline, acid and enzymatic catalysis was highlighted. And, among the main raw materials used in the production process are: vegetable oils, animal fats and oils and fats; as economically and environmentally viable alternatives. Still referring to the raw materials, there are the alcohols: methanol and ethanol, which are frequently used. In this way, the most varied catalytic methods present in the literature were presented. For each catalytic process, the work was presented, which developed methodologies for: homogeneous, heterogeneous catalysts, dispersed or immobilized, with the most diverse raw materials, which are currently used or that may be used in the process of obtaining biodiesel in the future. Industrial scale.

A solar tracker can be defined as an electromechanical system capable of following the apparent path of the Sun, in order to orient an array of solar panels and/or collectors directly to the solar rays, maximizing the collected energy. Accordingly, the present work describes the process of building and automating a micro-controlled solar tracker. Two mobile structures were built, one equipped with high-precision step motors and four luminosity sensors separated in quadrants by a cross structure, and the other equipped with DC motors and the 275 Wp solar panel, allowing the design and evaluation of the behavior of each structure separately. The control and automation system is centralized in an Arduino MEGA2560 microcontroller, which runs the tracking and positioning algorithms. The built prototype allows us to carry out studies of solar tracking strategies based on sensor and control systems applied to DC motors.

Countless problems have been caused by the excessive emission of polluting gases, such as carbon dioxide (CO₂), into the atmosphere. Therefore, more effective monitoring of CO₂ is essential, especially in central or industrial regions. Thus, this work shows the development of a platform for monitoring the CO₂ concentration, which is composed of autonomous and independent sensors that have their own energy source, storage capacity, and data replication for the central server. To validate the platform, CO₂ measurements were taken at three strategic points in an outdoor environment in a Brazilian urban center. This platform proved to be an evolution over another system previously proposed by the group that was based on the use of a wireless network of sensors to monitor CO₂. This new project managed to overcome limitations that compromised the efficiency of the first platform, which were mainly related to the interference in the communication signals between the network sensors due to the existence of physical barriers in the monitoring environment. With that, this new platform showed greater security in the maintenance of collected data and allowed for the expansion of the physical complexity of the environments that can be monitored.