The Catalytic Production Of 1,3-Butadiene From Ethanol

1,3-butadiene is an important building block for the chemical industry, which is widely used in different fields.1,3-butadiene is a coproduct of the cracking of naphtha. With the increasing depletion of fossil resources, it is important and worthy to find alternative and renewable resources for fuels and chemicals. With the decreasing cost of ethanol, the bio-based process could be a promising substitute for the dominant naphtha-based method.This study focus on the development of catalysts in the Lebedev one-step process and two- step process for the conversion of ethanol into 1,3-butadiene. The reaction mechanism is discussed also.In the first part of this work, MgO/silica gel was chosen through the screening of a variety of SiO2 carrier. It was found that MgO/SiO2 ratio at 4:1 reached the best butadiene selectivity. In order to further improve butadiene selectivity, a series of M-MgO/SiO2(4:1) were prepared. It was found that 1%Cu-MgO/SiO2(4:1) reached the best catalytic activity with selectivity of 61% and ethanol conversion of 71%. Based on the distribution of products, the improvement of the butadiene selectivity mainly comes from the increasement of acetaldehyde production.In the second part, the conversion of ethanol to 1,3-butadiene with the two-step process was researched on MgO/SiO2 catalyst. It was found that different MgO/SiO2 ratio caused the change of acid/alkali properties of the catalyst. When MgO/SiO2 ratio is set at 35:65, the catalyst showed the lowest acid strength and moderate strength of alkali, and reached the best butadiene selectivity of 75%. Moreover, it is confirmed that the introduction of acetaldehyde can improve the butadiene selectivity by inhibiting the production of ethylene and diethyl ether。...