METHOD FOR PRODUCING TETRAHYDROFURAN

PROBLEM TO BE SOLVED: To provide an industrially advantageous method for producing tetrahydrofuran by cyclodehydration reaction of 1,4-butanediol as a raw material, which can suppress reduction of reaction rate and stably achieve high productivity.SOLUTION: This production method of tetrahydrofuran comprises steps of: preparing a catalyst liquid by dissolving an acid with ≤4 pKa using 1,4-butanediol or tetrahydrofuran with 0.003-20.0 wt.% water content; preserving the catalyst liquid and thereafter, feeding the catalyst liquid to a reactor together with the raw material 1,4-butanediol; and conducting cyclodehydration reaction in the reactor to obtain tetrahydrofuran as the product.