| High efficiently utilization of mixed C4 olefins riched in China has become a focus of the chemical industry.Hydroformylation,which can convert C4 olefins into the high value-added 2-propyl hept-anol(2-PH),is an effective way to utilize the mixed C4 olefin resource.It has a technical feasibility and a great of economic potential,but the technology of hydroformylation has not been mastered in China,especially in ligand of the catalyst system.The purpose of this paper is to develop domestic hydroformylation ligands with independent intellectual property rights for industrial application.In this paper,the preparation technology of a novel bisphosphate ligands was developed for hydroformylation of mixed C4 olefins,at the same time the small-scale evaluation trial,field sideline evaluation trial and industrial application trial of the ligand were carried out,and the catalytic and application performance were investigated step by step.Firstly,according to the space effect,electronic effect and synergistic effect of ligands,the specific structure of a novel bisphosphite ligand with biphenol as skeleton and a certain amount of large volume substituents was determined.Secondly,the synthetic route of ligands was designed: the first step is to synthesize substituted biphenols,the second step is to synthesize bisphosphite ligands,and the process conditions of each step were optimized.The optimal synthesis conditions of substituted biphenol were as follows: based on the mole of substituted phenol,the oxidizer is 3.65 Eq.,sodium hydroxide is 1.0～1.1 Eq.,catalyst is 2.0% Eq.,solvent is 12 Eq.,reaction temperature is 55～65 ℃,reaction time is 5～7 h.Under these conditions,the optimal yield was 87.5% in experimental systhesis,84.2% in pilot-scale synthesis and 81.7% in industrial production,respectively.The optimum conditions for the synthesis of bisphosphite ligands were as follows: based on the mole of biphenol,three raw material ratio of biphenol、phosphorus trichloride and substituted biphenol is 1:1.5:0.45,organic base is 3.0 Eq.,reaction is at 30 ℃for 12～16 h,and then at 60℃ for 2～3 h.Under these conditions,the optimal yield was 78.9%in experimental synthesis,75.4% in pilot-scale synthesis,and 69.1% in industrial production,respectively.Finally,the catalytic and application performance of the bisphosphite ligands were evaluated using mixed C4 olefins as raw materials.The conversion and the ratio of normal to isomer valeraldehyde(n/i)were 88.5% and 19.4 in the experimental evaluation trial.The conversion and the n/i ratio were 86.5% and 17.2 in the field sideline evaluation trial.In the industrial application trial,the conversion and the n/i ratio which can reflect the catalytic performance of the self-made ligand were 85.8% and 16.5 respectively,which met the requirements of the industrial unit is not less than 80% and 15 respectively,and higher than85.8% and 16.2 of the foreign ligand respectively;The concentration of the monophosphate、diphosphate and iso-BHT-Diol which can reflect the anti-oxidant and anti-hydrolytic stability of the self-made ligand were 188ppm、86ppm and 2.46%,respectively,which were lower than221 ppm,123ppm and 2.96% of the foreign ligand respectively;The period to make up of ligand solution was extended from 7 days for the foreign ligand to 10 days for the self-made ligand,and the ligand replenishment flow was decreased from 35 kg/h to 30 kg/h accordingly,which can reflect the consumption of the ligand.The overall investigation of the self-made ligand was carried out from the small-scale evaluation trial、 field sideline evaluation trial to industrial application trial,it has been proved that the newly developed bisphosphite ligand have excellent catalytic performance,good application performance and notable economic superiority.The self-made ligand can fully meet the requirements of the industrial production units,and has considerable advantages in selectivity,stability and consumption compared with the foreign similar ligand and has a good prospect in industrial application. |
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