Experimental study to improve bio-ethanol yield from Iraq dates crop

Abstract EN

Bio-ethanol can be produced from different agricultural crops such as sugar cane, beat root, dates, etc.

In Iraq the Zahdi species of dates is produced in very large quantities with good sugar content so it is chosen for the production of bio-ethanol.

This research presents the possibility of improving the bio-ethanol yield from dates and to reduce the production cost.

A special rig is designed and assembled for this purpose.

Dates juice is available in local markets so it is used as the raw material for the production.

Ordinary production process includes many stages namely; fermentation, distillation and dehydration.

All these stages are carried out under atmospheric pressure.

Two techniques are tested in this research.

The first technique is to add another stage for the production stages which is a pre-treatment heating process of date juice in a microwave oven before the fermentation process in order to reduce the fermentation time.

The second technique is to carry out the distillation and dehydration stages under vacuum pressure.

Two vacuum pressures are tested namely 0.5 and 0.7 bar vacuum.

It is found that the pre-treatment of the juice in the oven reduces the fermentation time.

Three residence times in the oven are tested namely (10, 20 and 30 min) at 140 oC.

When the residence time exceeds 30 min the sample burns in the oven.

The fermentation time for these residence times decreases by 8.3, 20.8 and 29% respectively.

The reduction in fermentation time reduces power consumption and hence production cost.

The fermentation process is followed by the distillation process under vacuum pressure, which includes three stages.

Two experiments are done one under a vacuum pressure of 0.7 bar while the other under a vacuum pressure of 0.5 bar.

Different evaporation temperatures are tested for each stage to obtain the best temperature for each stage which gives the shortest time and the highest concentration.

It is found that carrying out the distillation process under vacuum reduces the total distillation time by about 32%.

As the vacuum pressure increases the total distillation time decreases due to lower evaporation temperature.

Finally, dehydration process under vacuum pressure is the most important and difficult process because it takes a longer time to produce the required concentration of ethanol.

It is found that carrying out the dehydration process under vacuum reduces the total dehydration time about 33%.

This process involves the use of different types of drying materials (ethylene glycol and calcium oxide).