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Studies On The Synthesis Of Vitamin PP And 3-Picoline

Posted on:2005-02-03Degree:MasterType:Thesis
Country:ChinaCandidate:S G HeFull Text:PDF
GTID:2121360122971450Subject:Biochemical Engineering
Abstract/Summary:PDF Full Text Request
Currently, it is mainly to use formaldehyde, acetadehyde and ammonia as raw materials by gas-solid phase reaction to produce 3-picoline.But the selectivity is low with many kinds of by-products,which makes it very difficult to separate the desired products.In the present study,a liquid phase reaction was selected. High selectivity(59.3%) and yield(24.3%) were achieved by the usage of sodium hydrosulfate and amino as catalyst. When diammonium hydrogen phosphate is used as catalyst with formaldehyde and acetadehyde as the first educt,the optimal conditions to synthesize 3-picoline are: temperature 220# , pressure2.5 ?3.5bar, stirring speed 200rpm,ammonia/organic phase 4/1, acetadehyde/ formaldehyde 1:1, the aldehyde mixtures are pumped within 10-20 minutes and without the addition of N2. Under this optimal codition, acraldehyde was added as the second educt gives striking selectivity(68.9%) and yield(35.4%),which can be sepatated and purified,giving 94.9 percent.By further analysis.we can get that the mole ratio of ammonia/organic phase is the most important factor and tempreture is the least important factor influence the yield and selectivity of 3-picoline.Vitamine PP, including nicotinic acid and nicotinamide.belonging to vitamine B, are very important vitamines.They are important in medical ,food,and feedingstuff industry.Presently.they are produced by chemical synthesizing methods.Generally, there are such shortcomings in conventional methods:low yield, fearful pollution.high cost and low efficiency,etc.So,a method with high yield , low cost and light pollution has been developed.In this research,nitric acid was used as oxidizer to oxidize 3-picoline under usual pressure to produce nicotinic acid.with a yield more than 110 percent(m/m).The transforming rate of 3-picoline is more than 98 percent.The production rate of nicotinic acid can be characterized as:; the relationship of kR and T can be desicribed asNitric acid with 35-65 percent concentration can be used,60 percent can give relative better result.For the waste nitric acid ,more than 75 percent can be reclaimed.NOx and the unreacted 3-picoline can be transformed to N2 CO2 and H2O by oxidation-deoxidization method. In a word,the virtue of this method can be pictured as:high yield, low cost, excellent quality and mild reaction condition.
Keywords/Search Tags:3-Picoline, Liquid Phase, Synthesis, Vitamine PP, Nitric Acid, Oxidation-Deoxidation
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