Dewatering of brewer’s spent grain using an integrated membrane filter press with vacuum drying capabilities

ABSTRACT

Brewer’s spent grain (BSG) is a by-product of the brewing process, rich in fiber, protein and carbohydrates. Its potential application is limited because of high moisture content (80%). This work presents a process for dewatering BSG using two different sets of membrane filter plates in a filter press with vacuum drying: recessive plates with polypropylene membranes and the innovative Rollfit^® plates. A final moisture content of 12-15% was obtained in 15 mm-thick filter cakes, using both types of plates. The dewatering cycle included filtration, membrane-squeezing, and vacuum thermal drying using hot water (~90ºC) as heat source.

KEYWORDS:

• Spent grain
• filtration
• filter press
• vacuum-drying
• membrane plate

Acknowledgements

The authors would like to thank Unicer Bebidas, SA, for promoting this project.

Additional information

Funding

AdI, Agência de Inovação’s financial support is gratefully acknowledged for the project DRECHE – “Tecnologias ambientais para a valorização de resíduos da indústria”, 3^rd call no. 70/136, 2005, PRIME IDEIA Program.