A method for extracting hydrolysate， a batch cooking system and a hydrolysate extracting arrangement

A method for extracting hydrolysate in a batch cooking process for producing pulp， said method comprising the steps of:- providing lignocellulose raw material to a batch cooking vessel;- performing acid hydrolysis of the lignocellulose raw material in the batch cooking vessel;displacing a first part of a hydrolysate from the batch cooking vessel by adding to the batch cooking vessel at least one first displacement liquid comprising recycled hydrolysate from a hydrolysate recirculation tank， wherein said recycled hydrolysate has been transferred to the hydrolysate recirculation tank from the batch cooking vessel during a previous batch cooking process;receiving the first part of the hydrolysate in at least one hydrolysate extraction tank;displacing a second part of the hydrolysate from the batch cooking vessel by adding to the batch cooking vessel at least one second displacement liquid comprising alkaline neutralization liquor; andreceiving the second part of the hydrolysate in a hydrolysate recirculation tank.