在国内外,由于苯的用途广、用量大,随着合成纤维工业的发展,二甲苯的需要量也日益增加,以致在石油化学工业中,甲苯、苯和二甲苯的供求不平衡,甲苯生产过剩,而苯和二甲苯短缺。为此,利用歧化反应使甲苯转化为苯和二甲苯的工艺引起广泛的重视。甲苯歧化反应如下: At home and abroad, due to the wide use of benzene, large amount, with the development of synthetic fiber industry, the demand for xylene is also increasing, so that in the petrochemical industry, toluene, benzene and xylene supply and demand imbalances, toluene production Excess, while benzene and xylene shortage. To this end, the use of disproportionation reaction toluene into benzene and xylene process attracted widespread attention. Toluene disproportionation reaction is as follows: