Seawater could be used to lower freshwater footprint of bioethanol

New research shows that seawater could be used in place of freshwater for the production of bioethanol, lowering the process’ water footprint.

In a study published in the journal Scientific Reports, scientists from the University of Nottingham show that when combined with a new strain of marine yeast, the seawater can be used to replace freshwater during fermentation.

"Current fermentation technologies mainly use edible crops and freshwater for the production of bioethanol,” said Dr. Abdelrahman Zaky, a microbiologist in the School of Biosciences at the University of Nottingham.

“With an ever growing population and demand for biofuels and other bio-based produces, there are concerns over the use of the limited freshwater and food crops resources for non-nutritional activities. Also, freshwater has a high price tag in countries where it is available, pushing up the price of production."

For the research, Zaky and colleagues used seawater from the Lincolnshire coast and marine yeast samples from locations in the UK, US and Egypt. These were put through the fermentation process in laboratories in the Bioenergy and Brewing Sciene Building at the University’s Sutton Bonington campus.

According to a University of Nottingham statement, it is estimated that between 1,388 and 9,812 litres of freshwater are consumed for every litre of bioethanol that is produced.

Dr. Zaky said: "The main purpose of marine fermentation is to introduce an alternative source of water and biomass for industrial biotechnology in order to reduce pressure on use of freshwater and arable land, allowing these resources to be dedicated to production of food and feeds an reducing production costs. Marine fermentation is the approach where seawater, marine biomass and marine microorganisms are used in the fermentation process.

"Seawater is a freely available and plentiful resource, and contains a spectrum of minerals, some of which have to be added to freshwater. The fermentation process using seawater also produces salt and freshwater as bi-products adding to economic benefits of the process."

The study, titled ‘The establishment of a marine focused biorefinery for bioethanol production using seawater and a novel marine strain’, is available here.