Patent ID: 9199895
Filing Date: 2015-12-01
Classification: B01J,C07C

Abstract:
1. A method for preparing 1,3-butadiene as a high yield comprising the steps of: a) charging a bismuth molybdate-based multimetal elements oxide catalyst wherein the multimetal elements consist of Mo, Bi, Fe, Co, and Cs as a first catalyst in a first reactor as a first catalyst fixed bed; b) charging a potassium bismuth molybdate-based multimetal elements oxide catalyst wherein the multimetal elements consist of Mo, Bi, Fe, Co, Cs, and K as a second catalyst into a second reactor connected to the first reactor in parallel as a second catalyst fixed bed; simultaneously or sequentially with step (a), c) introducing a C4 mixture comprising 1-butene, 2-butene and normal butane to a distillation column without any solvent to obtain a low-boiling point fraction comprising mainly 1-butene and a high-boiling point fraction comprising mainly 2-butene; d) continuously passing the low-boiling point fraction, air and steam to the first reactor to conduct oxidative dehydrogenation; e) continuously passing the high-boiling point fraction, air and steam to the second reactor to conduct oxidative dehydrogenation; and f) separating reaction effluents obtained from the first reactor and the second reactor into a 1,3-butadiene stream, a normal-butene stream and a C4 mixture stream, wherein the process for preparing the first catalyst comprises: a1) preparing a first solution containing a cesium precursor, a cobalt precursor and an iron precursor, b1) preparing a second solution containing a bismuth precursor, c1) preparing a third solution containing a molybdenum precursor, d1) adding dropwise the second solution to the first solution, followed by mixing, to prepare a fourth solution, e1) adding dropwise the fourth solution to the third solution to prepare a first co-precipitation solution, f1) stirring the first co-precipitation solution for one to two hours and removing moisture to obtain a first solid component, and g1) drying the first solid component in the range of 150 to 200° C. and thermally treating the first solid component in the range of 400 to 600° C. to obtain the bismuth molybdate-based multimetal elements oxide catalyst wherein the multimetal elements consist of Mo, Bi, Fe, Co, and Cs, and wherein the process for preparing the second catalyst comprises: a2) preparing a first solution containing a potassium precursor, a cesium, precursor, a cobalt precursor, an iron precursor and a bismuth precursor, b2) preparing a second solution containing a molybdenum precursor, c2) adding dropwise the second solution to the first solution to prepare a second co-precipitation solution, d2) stirring the second co-precipitation solution for one to two hours and removing moisture to obtain a second solid component, and e2) drying the second solid component in the range of 150 to 200° C. and thermally treating the second solid component in the range of 400 to 600° C. to obtain the potassium bismuth molybdate-based multimetal elements oxide catalyst wherein the multimetal consist of Mo, Bi, Fe, Co, Cs, and K.