Building a Biodigestor Prototype to Generate Biogas From Sargassum

Purpose & objective

Invetigate the various existent processes to convert organic waste into methane gas
Invesigate the composition and chemical properties of algae Sargassum for the correct use in the project
Knowing the function of a biodigestor to design a similar device
buil the prototype for a biodigestor with recycled materials to obtain methane gas
measuring the quality of obtained gas and define the right use for it

Outline

The project will be explained detailed in the whole process since the creative part, research and modeling to the building of the actual prototype.

Objectives:
1. Investigate the various existing processes to convert organic waste into methane
gas.
2. Investigate the composition and chemical properties of Sargassum algae, for its correct implementation in the project.
3. Know the functioning of a biodigester for the design of a similar prototype.
4. Build a prototype biodigester from recycled material that efficiently converts sargassum into gas.
5. Measure the quality of the methane gas obtained, to define the ideal application for it.

Pesperctives

The problem of sargassum in the Mexican Caribbean is increasing, since 2011 this algae has arrived with greater frequency and quantity. But, in 2018 the macroalgae hit the coasts of the Mexican Caribbean with all its force, being the year where the highest volume of sargassum was recorded. This caused endless problems in various aspects, economic spillover, tourism in the area and damage to marine ecosystems.

That was when Mexican ingenuity and talent was present, developing innovative proposals that use sargassum as the main raw material. The organic use of one of the main ecological problems of the Mexican Caribbean, sargassum, has just begun, just 5 years ago, studies are being carried out to determine the benefits and risks that said macroalgae generates at an ecological level.

In relation to biodigesters, there are various models and at different scales, the most widely implemented being the modular, bag and tank. All models are designed to carry out the anaerobic digestion process of organic waste generated from agricultural and livestock activities. Its effectiveness has been proven with these primary sources of digestion, generating methane gas and natural fertilizers that regenerate the soil and allow better crops.
As for the biodigestion of sargassum, it is a field very little explored in the world, where the students of the Cumbres Cozumel Institute seek to make a technological contribution that allows the entire community of Cozumel to generate biogas.

Search methods

We are working on the design of a prototype biodigester, from recycled material, capable of converting sargassum or organic waste into methane gas for human consumption. From the analysis of previous research, it is concluded that this macroalgae is composed of chemical elements that allow the conversion of sargassum into methane gas.
The proposed biodigester, reactor, consists of a hermetic cabin, made of iron or aluminum in the shape of a cylinder, where at high temperatures, higher than 80 ° C, sargassum in combination with water, generates a greenhouse effect environment releasing the particles, Mostly methane gas, the gas contained on the surface of the biodigester can be stored in another container where it can be used at another time, or be implemented directly for human consumption, applied to a stove, gas lamp, etc.
The gas outlet is located in the upper part of the biodigester, where through a regulatory key the distribution is controlled and the volumetric quantity of gas generated is monitored.

Results or expectations

Results at the moment
When conducting research on non-industrialized biodigesters, we noticed that most are made manually, where they mainly use animal feces and organic waste.
We are beginning the biodigester development stage, analyzing design options, as well as the quality of the gas generated by subjecting the sargassum to high temperatures by means of a sensor. We want to know if at these temperatures other gases are not generated, by the container material, that affect the quality of the methane gas.
In the same way, we want to implement a safe, mechanical or electronic regulation system, at the exit of the container, avoiding losses or dangerous accidents.
Expectations
The benefits and possibilities of this macroalgae are diverse, that is why we are sure to obtain a functional prototype that helps to conserve our extraordinary coasts and the large amount of marine life they protect, while producing resources that help several families of the island naturally; promoting the sustainability of Cozumel.

Educational or scientific importance

Educational: we are sure that by actively motivating and involving our students to solve real-life problems, where almost all areas of learning intervene, we exploit their skills and knowledge to the fullest, generating awareness for the care of the environment, sowing the seed of research and affection for continuing to study areas related to STEM, which the country urgently needs.

Scientific: In Mexico, ideas and research related to the benefits and applications of sargassum are just beginning to emerge, highlighting universities such as UNAM, IPN or UAM, as well as great ideas from Caribbean entrepreneurs in the country making paper, bricks and shoes to through processing said macroalgae.
The contribution we seek to offer is to demonstrate the effectiveness and quality of the methane gas produced by sargassum, from a low-cost biodigester, built locally in Cozumel, which allows sustainable development of the island, providing benefits to the marine ecosystem of the area. and promoting scientific and technological research, converting the natural resources that come to us, into growth opportunities.

Supporting research

References
1. https://iresiduo.com/noticias/mexico/conacyt/18/05/04/como-producir-metano-partir-desechos-organicos-generados-hogar#:~:text=El%20biodigestor%20se%20alimenta%20con,y%20las%20bacterias%20metanog%C3%A9nicas%20act%C3%BAan.
2. https://www.conacyt.gob.mx/sargazo/index.php/materiales-de-consulta/18-materiales/99-arribo-de-sargazo-a-las-costas-mexicanas-2
3. https://www.eleconomista.com.mx/arteseideas/La-Ibero-estudia-composicion-quimica-del-sargazo-para-aprovecharlo-20190527-0098.html
4. https://www.greenpeace.org/mexico/noticia/3055/es-el-sargazo-realmente-malo/
5. https://rotoplas.com.mx/para-que-sirve-el-biodigestor/#:~:text=El%20biodigestor%2C%20realiza%20un%20tratamiento,abono%20o%20fertilizante%20para%20plantas.
6. https://ecotec.unam.mx/ecoteca/biodigestores-2
7. https://ecotec.unam.mx/wp-content/uploads/Especificaciones-para-el-Dise--o-y-Construccion-de-Biodigestores.pdf