Abstract:
The carrier of the present invention includes at least 85 wt percent alpha alumina, at least 0.06 wt percent SiO2 and no more than 0.04 wt percent Na2O. The carrier has a water absorption no greater than 0.35 g/g and a ratio of water absorption (g/g) to surface area (m2/g) no greater than 0.50 g/m2. Another aspect of the invention is a catalyst for the epoxidation of olefins which comprises the above described carrier and silver dispersed thereon, where the carrier has a monomodal, bimodal or multimodal pore distribution and where the quantity of silver is between 5 and 50 wt %, relative to the weight of the catalyst. A reactor to system for the epoxidation of olefins is also disclosed.
Abstract translation:本发明的载体包括至少85wt%的α氧化铝,至少0.06wt%的SiO 2和不超过0.04wt%的Na 2 O. 载体的吸水率不大于0.35g / g,吸水率(g / g)与表面积(m2 / g)不大于0.50g / m 2。 本发明的另一方面是用于烯烃环氧化的催化剂,其包含分散在其上的上述载体和银,其中载体具有单峰,双峰或多峰孔分布,并且其中银的量为5至50重量% 相对于催化剂的重量。 还公开了用于烯烃的环氧化反应器的反应器。
Abstract:
The selectivity and activity of a silver-based olefin epoxidation catalyst is found to be a function of the pore size distribution in the alumina carrier on which it is deposited. Specifically it is found advantageous to provide a carrier which has a minimum of very large pores, (greater than 10 micrometers) and a water absorption of 35 to 55% and a surface area of at least 1.0 m2/g. A method of making such carriers is also described.
Abstract:
A carrier, which comprises non-platelet alumina and/or a bond material, has a surface area of at least 1.3 m2/g, a total pore volume and a pore size distribution such that at least 80% of the total pore volume is contained in pores with diameters in the range of from 0.1 to 10 μm, and at least 80% of the pore volume contained in the pores with diameters in the range of from 0.1 to 10 μm is contained in pores with diameters in the range of from 0.3 to 10 μm, and a process for the preparation of a carrier which comprises forming a mixture comprising: a) from 50 to 95 weight percent of a first particulate α-alumina having a median particle size (d50) of from 5 to 100 μm; b) from 5 to 50 weight percent of a second particulate α-alumina having a d50 which is less than the d50 of the first particulate α-alumina and which is in the range of from 1 to 10 μm; and c) an alkaline earth metal silicate bond material; weight percent being based on the total weight of α-alumina in the mixture; and firing the mixture to form the carrier.
Abstract:
A carrier, which comprises non-platelet alumina and/or a bond material, has a surface area of at least 1.3 m2/g, a total pore volume and a pore size distribution such that at least 80% of the total pore volume is contained in pores with diameters in the range of from 0.1 to 10 μm, and at least 80% of the pore volume contained in the pores with diameters in the range of from 0.1 to 10 μm is contained in pores with diameters in the range of from 0.3 to 10 μm, and a process for the preparation of a carrier which comprises forming a mixture comprising: a) from 50 to 95 weight percent of a first particulate α-alumina having a median particle size (d50) of from 5 to 100 μm; b) from 5 to 50 weight percent of a second particulate α-alumina having a d50 which is less than the d50 of the first particulate α-alumina and which is in the range of from 1 to 10 μm; and c) an alkaline earth metal silicate bond material; weight percent being based on the total weight of α-alumina in the mixture; and firing the mixture to form the carrier.