Another key point of the reaction is the amount and type of catalyst.these aspects of the catalyst has a close relationship with the oil yield rate, and the quality of the oil. When we add the catalyst into the reaction the temperature needed to paralyze the will decline. And we will choose the final products. And we can change the percentage of the final products. The catalyst will change the reaction rate and more, and then we can control the reaction. Besides the type, the amount of the catalyst has an important impact on the final products