Brewer’s spent grain-based biochar as a renewable energy source and agriculture substrate

Abstract

This work focuses on brewer’s spent grain (BSG) slow pyrolysis and examines the influence of the pyrolysis temperatures on the BSG biochar properties. The BSG biochar suitability as an energy vector, emphasizing its potential as a biofuel, was evaluated. Moreover, the biochar effects on lentil sprout germination were assessed, having practical implications for industries involved in seed production, nursery operations, and crop cultivation. Pyrolysis tests at 673, 773, and 873 K were carried out. Bioenergy indexes were calculated, and germination tests were carried out to obtain lentil sprouts. The BSG biochar obtained at 673 K presented the best performance for use as biofuel. Regarding the germination tests, the different biochar was applied at 4 doses, and the addition of biochar strongly influenced the evaluated parameters. The biochar obtained at 773 K and added at a dose of 5% doubled the values of mean germination time, seed vigor, and time for 50% of the seeds to emerge compared to the control, constituted only with distilled water. This evaluation adds a novel aspect providing valuable insights into the optimal pyrolysis conditions for producing BSG biochar, considering its use as an energy vector and substrate to obtain lentil sprouts.