Development of production process of charcoal bricks from spent grain

A process was developed for production of charcoal bricks from spent grain from it beer brewery, and the physical and chemical properties of the charcoal bricks roduced were evaluated. The beer spent grain (water content 67 wt%) was first dried, then pressed at high temperature and pressure to make bricks without any binder. Finally, the spent grain bricks were carbonized in a low oxygen atmosphere to produce charcoal bricks. The heat recycling carbonization method, in which a part of carbonization gas Output was returned to the carbonization furnace, was applied to the carbonization of the bricks. This method yielded charcoal bricks with a constant quality and high yield. The charcoal bricks had a high calorific value of about 27 MJ/Kg, which was equipollent to that of Bincho tan and was about 13% lower than that of Oga-tan. The contents of nitrogen and phosphorus in the charcoal bricks were 9-20 times and 40 times greater than those of Bincho-tan and Oga-tan, respectively. As the spent grain charcoal bricks contained various minerals such as calcium, magnesium and phosphorus, they had the possibility to be used as a source of natural minerals.