This document describes an experiment to produce ethanol from cellulosic biomass. The process involves grinding biomass into a powder, mixing it with hot water and alkali to break it down, adding yeast and enzymes, and allowing fermentation for 72 hours to convert sugars into ethanol and carbon dioxide. The experiment resulted in a bioethanol recovery percentage between 27-39% depending on the type of cellulosic feedstock used.

1. ERG 211 RENEWABLE ENERGY AND GREEN
TECHNOLOGY (1+1)
Practical - 3
Experiment on Bio-ethanol Production
Aim: To produce ethanol from cellulosic biomass

2. Experiment on bioethanol production
Principle:
Ethanol fermentation (alcoholic fermentation) is a process
in which sugars are converted into alcohol and carbon
dioxide by the action of yeasts / enzymes.
The reaction is as follows.
C6H12O6 → 2C2H5OH + 2CO2

3. Flowchart of ethanol production from cellulosic materials

4. Materials for bio-ethanol production
Materials required
 Powdered cellulosic biomass,
 Conical flask,
 Yeast
 Distillation unit and
 Cotton.

5. Materials and Methods for bio-ethanol production
Procedure
1. Grind the cellulosic biomass into fine powder using
hammer mill.
2. Mix the known quantity of powdered biomass with
hot water to form slurry in a flask.
3. Mix the biomass slurry with 3% alkali (lime) for 30 min
and keep it in autoclave at 121°C for 1 h.

6. Materials and Methods for bio-ethanol production
Procedure
4. Wash the chemically treated biomass slurry with water
to remove alkali and neutralize with acetic acid.
5. Add yeast (10% v/v) and cellulase (0.23 ml / g) in the
treated biomass slurry and keep it under anaerobic
condition at atmospheric temperature for 72 h.
6. Estimate the ethanol production by colorimetric method.

7. Bio-ethanol production
Observation
Weight of the Cellulose biomass = 20 g
Volume of hot water = 30 ml
Weight of yeast = 0.4 g
Result
Bioethanol recovery % from cellulose = 27 to 39 %
depending upon the type of feedstock used