Zefiro was created as my college's Final Project, an urban furniture item that aims to improve air quality and provide street lighting. According to the WHO, 7 million people die yearly because of bad air quality. That’s why I decided to develop a project to improve air quality. For the development of this project, I was able to obtain the help of several professors from the departments of Biology, Design, Electrical Engineering, Mechanical Engineering, and Chemistry, who assisted me with theoretical questions and the analyses I made.
sketches- shape study
Zefiro has an internal structure made of fiber clay, a mixture of clay with sisal fiber in a ratio of 1: 3 (sisal: clay). Mixed to the composite was added Titanium Dioxide, a photocatalyst that can draw up to 100m³ / m² of TiO2 - containing surface of pollutants per day without decomposing. Its external structure can be coupled with several plants, which have the natural function of removing pollutants from the air and removing particulate matter from the air, which is trapped on the surface of the plants according to their morphology. It can be docked 48 plants around the Zefiro. Depending on the species chosen (such as 40 meter-fern, which would give about 24m² of green area), Zefiro can capture about 800kg of air pollution per year.
For an item made to be placed in a public space, it was thought about the possibility of providing public lighting. For this, I conducted some research about the best source of renewable energy to be used as Zefiro's energy source. This research eventually became a concept on which I based my project (circular economy). For that, I began to research heliothermic energy and possibly developing a plant on a smaller scale than usual. The project was chosen to work with the solar tower, which usually is about 195 meters high. With the help of the electrical and mechanical engineering department professors, we designed a heat exchanger with concentric tubes about 2 meters high. During the six months, I did not have time to develop the solar concentrator that would be used, but the chosen one was the Fresnel lens.
representation of the solar concentrator
heat exchanger - concentric tubes
inner tube - water
outer tube - molten salt
inside the structure
Obviously, a heliothermic plant is not the most appropriate to work on, not only because of the technical challenges but also because of the energy yield vs. the amount of energy used in the system. But as I argued in my project that we need diversification of the Brazilian energy matrix, yet the Brazilian government does not invest in new sources of energy and does not give the incentive to research in the area, I conceptually approached the heliothermic energy, and it was great because I could learn a lot about renewable energy and the operation of a heliotérmica plant.
Software used to develop this project:
Solid Works - for the technical drawing and development of the structure
MatLab - to make all the calculus for the project, as the sizing of the heat exchange
I also developed an irrigation system to keep the plants hydrated, not only to keep them alive but because their capacity to absorb pollutants is directly related if they are being well watered and if they are planted in a good soil.
For that system was used:
Water Level Sensor
Zefiro prototype was made in a 1:5 scale for a college exposition.
Two samples were made to analyze the fiber clay's photocatalytic power and how much pollution it absorbed during one month. 40g of fiber clay was used in one sample, and 40g of fiber clay + 2g of TiO2 in another. After preparing the samples, they were taken to a muffle at 250ºC for 15 minutes.
After one month, the samples were taken to the Analytical Chemistry Center of PUC-Rio to be submitted to an x-ray analysis, which revealed qualitatively and quantitatively the amount of pollution absorbed by the 40g sample for one month, approximately 2 kg.