Tema
Energías renovables

Palabras clave
Waste, lemon, orange, cellulase, yeast, ethanol

Introducción

At present, large cities that do not have a solid waste separation system and subsequent use are facing the rapid use of their sanitary landfills and a decrease in their environmental quality due to this problem.
One of the possible solutions is to take advantage of the organic matter discarded in homes since they contain cellulose, a compound that can be used to generate fertilizers, fertilizers or can also be included in the production of clean energy such as bioethanol. 

Objetivos

1. Quantify the yield to bioethanol from orange and lemon residues.
2. Analyze the effect of cellulolytic enzymes during the fermentation process of orange and lemon.

Método

In the present work, lemon and orange residues have been used, with a characterization of samples with the following parameters: moisture (%), ash (%), fat (%w/v), protein (%w/v), reducing sugars (RS) (%w/w), and carbohydrates (%w/w). Since the residues have a significant amount of cellulose, hemicellulose and lignin, a controlled process was applied through the use of treatments such as thermal hydrolysis (TH), by using were the autoclave with a temperature of 121°C, at a pressure of 1 atm for 20 min, and enzymatic hydrolysis (EH), with cellulase enzyme of the Aspergillus sp. species (Sigma Aldrich), which release reducing sugars (RS), and the subsequent measurement of ethanol obtained by using a gas chromatography with flame ionization detection (GC-FID).

Principales Resultados

The results obtained by the thermal and enzymatic action on the lemon residues increased the amount of reducing sugars from 3.99 g / L (initial residue) to 7.65 g / L.
In the orange residues a similar behavior was obtained since the concentration of reducing sugars was doubled from 2.45 g / L (initial residue) to 8.05 g / L.
These increases in reducing sugars were used by the yeast Saccharomyces cerevisiae in the fermentation process, and the consequent production of 1.65 g / L and 0.40 g / L of ethanol, from lemon and orange residues respectively.

Conclusiones