Abstract:

At the Faculty of Chemistry UNAM (Universidad Nacional Autónoma de México), the student at the last semester has to develop a practical project related to the chemical courses they have taken.

Ramón is an evergreen tropical tree which is extensively distributed in México; its scientific name is Brosium alicastrum. During the Maya civilization (400 to 1200 AC) it was widely used for food and forage. The current use of the tree is very limited. The challenge was to find alternative uses applying chemistry.

In order to solve the problem of finding new applications, a review of the literature was performed using specialized databases, and it was found that the starch is present in a large amount in the seeds. The students decided to use the starch as raw material to obtain biofuel. The first step was performing a hydrolysis to obtain single sugars, which can be fermented readily to bioethanol.

The traditional hydrolysis is performed using acid solution and heating the flour suspension for 2 to 6 hr.In the last years, the use of microwave in chemistry has increased due to the reduction of time, and increase yield, in several types of chemical reaction, hydrolysis is on of them. The students decided to adapt the use of a microwave to the hydrolysis of Ramon starch.

The task was to optimize the hydrolysis process using different acids, temperatures, and concentration of flour. The students took three types of media, water, sparkling water (carbon dioxide, dissolved in water) and Phosphoric acid solution ( 1%,3% and 5% in water). They change the amount of Ramón seed flour and temperature during the process. In order to find the best conditions of conversion. The optimized process gave a conversion of more than 96%.

Teaching student how to solve practical problems from everyday life is the best way of incentive them for a better understanding of the topic they are learning. The self-satisfaction of contributing with a positive answer to a real problem is very rewarding. The most important contribution to the course is to teach students how to find the right information for solving a particular problem using the proper informatics tools.

Keywords:

Chemistry, new skills, natural resources, hydrolysis.