• Citric acid was used as pretreatment catalyst for corn fiber. • Biodetoxification was conducted before saccharification to remove inhibitors. • Acetic acid from corn fiber was degraded in the reframed biorefinery chain. • A high ethanol titer of 70.2 g/L was achieved from corn fiber. Corn fiber is a byproduct of wet milling of corn grains with high hemicellulose content. Hemicellulose is only partially hydrolyzed in acid pretreatment and the complete hydrolysis occurs in the subsequent enzymatic hydrolysis. In the regular biorefinery chain of lignocellulose, the detoxification of toxic inhibitors is conducted immediately after pretreatment. When this process arrangement applies to corn fiber, acetic acid is accumulated to high level because of acetyl group release from residual hemicellulose. This study re-framed the biorefinery chain by conducting enzymatic hydrolysis before biodetoxification to completely release acetic acid from hemicellulose in corn fiber. Then the biodetoxification was followed immediately to degrade acetic acid, furfural and 5-hydroxymethylfurfural with the minimum loss of glucose and xylose. The improved ethanol production (70.2 g/L, or 8.9 % by v/v) was obtained by the re-framed chain of corn fiber biorefining. This study provided a practical approach for utilization of corn fiber for biofuel production. [ABSTRACT FROM AUTHOR]