Kinetic study and kinetic parameters of lipase-catalyzed glycerolysis of sardine oil in a homogeneous medium

The production of polyunsaturated fatty acids （PUFAs） concentrates by enzymatic catalysis has gained interest due to their stereospecificity and the milder conditions employed compared to the use of inorganic catalysts. The enzymatic glycerolysis of sardine oil by Lipozymeò435 to get PUFA concentrates in the forms of di‐and monoacylglycerols （DAGs, MAGs） in an optimized amount of tert‐butanol as the organic solvent was studied. First, mass transfer limitation of the reaction sys‐tem was analyzed. The effects of different operating variables such as lipase loading, temperature and feed composition were investigated. A semi‐empirical kinetic model based on the reversible elementary reactions of glycerolysis and hydrolysis of the glycerides was employed to correlate the experimental kinetic data. A molar ratio glycerol：oil of 3：1 was the optimum, which produced more than 84 wt%of MAG at 323 K. A comparison with other glycerolysis systems was performed using MAG yield, reaction rate and significance of kinetic parameters.

Application of Tertiary Amine Cationic Polyacrylamide with High Cationic Degree in Salt-free Dyeing of Reactive Dyes

Tertiary amine cationic polyacrylamide with high cationization degree was used as a new cationic agent to pretreat cotton with dip-pad-bake method. The obtained cationic cotton was dyed with reactive dyes in the ab-sence of electrolyte. The effects of the characteristics of the cationic agent and the pretreatment conditions on dye-ability of reactive dye were investigated. The results showed that the fixation and K/S values of the reactive dyes on the cationic cotton were improved compared with those on the untreated one in the presence of salt. Tests on fast-ness properties of the dyed cotton and fabric quality of the pretreated cotton were carried out and the results showed that wash and rub fastness of the salt-free dyeing were both satisfactory. And anti-crease property,tensile and tear strength,and handling of the cationic cotton were also good compared with that of the untreated one.

Phenol Tert-Butylation Catalyzed by Zeolite H-Mordenite

Para-tert-butyl phenol (p-TBP) and 2,4-di-tert-butyl phenol (2,4-DTBP) are widely used for the preparation of antioxidants. Zeolite catalysts showed good performance for the synthesis of p-TBP and 2,4-DTBP. In this work, zeolite H-mordenite (HM) catalyst was prepared and the alkylation of phenol with tert-butyl alcohol over zeolite HM catalyst was investigated at different reaction conditions. It is found that increasing temperature enhances the selectivity to p-TBP and the optimum reaction temperature for phenol conversion is 438 K. Increasing flow rate decreases phenol conversion apparently while the selectivity to p-TBP has a little increase. The suitable tert-butyl alcohol/phenol molar ratio is 2. Lower alcohol/phenol molar ratios are beneficial to p-TBP while higher ones are helpful for producing 2,4-DTBP.

Theoretical Study on Dissociation Mechanisms of Di-ethyl Berylliums and Di-t-butyl Berylliums

The potential energy surfaces （PES） of unimolecular dissociation reactions for di-ethyl beryl- lium and di-t-butyl beryllium are investigated by B3LYP, CCSD（T）, and G3B3 approaches. Possible reaction pathways through either the radical or transition state （TS） of the molecules are considered. The geometries, vibrational frequencies and relative energies for various sta- tionary points are determined. From the study of energetics, the TS pathways arising from concerted molecular eliminations are indicated to be the main dissociation pathways for both molecules. The PES differences of the dissociation reactions are investigated. The activation energies and rate constants will be helpful for investigating the predictive ability of the reaction in further theoretical and experimental research.

Alkylation of p-Cresol with tert-Butanol Catalyzed by Novel Multiple-SO_3H Functioned Ionic Liquid

The alkylation of p-cresol with tert-butanol（TBA）to 2-tert-butyl-p-cresol（TBC）catalyzed by a novel multiple-SO3H functioned ionic liquid（IL1）was investigated.Meanwhile,the catalytic activity of this novel ionic liquid was compared with other four traditional ionic liquids.The results showed that IL1 has superior catalytic activity to other four traditional ionic liquids with the conversion of 85.3%and selectivity of 95.2%.Also,the reaction conditions were investigated to obtain the optimum conditions.Operational simplicity,small amount of usage,high activity,reusability and selectivity are the key features of this methodology.

Venting Design for Di-tert-butyl Peroxide Runaway Reaction Based on Accelerating Rate Calorimeter Test

In order to design the relief system size of di-tert-butyl peroxide(DTBP) storage tanks,the runaway re-action of DTBP was simulated by accelerating rate calorimeter(ARC).The results indicated that under adiabatic conditions the initial exothermic temperature was 102.6 ℃,the maximum self-heating rate was 3.095×107 ℃·min-1,the maximum self-heating temperature was 375.9 ℃,and the pressure produced by unit mass was 4.512 MPa·g-1.Judged by ARC test,the emergency relief system for DTBP was a hybrid system.Based on Design Institute for Emergency Relief System(DIERS) method,the releasing mass flow rate W was determined by Leung methods,and the mass velocity G was calculated by two modified Omega methods.The two relief sizes calculated by monograph Omega method and arithmetic Omega method are close,with only 0.63% relative error.The monograph Omega method is more convenient to apply.

Study on Activated Bentonite Applied to tert-Butylation of Toluene

tert-Butylation of toluene with tert-butanol used as the alkylating agent was investigated over the activated bentonite and HY zeolite used as the catalyst.The influences of various butylation reaction parameters,including the toluene/tert-butanol ratio,the reaction temperature,and the space velocity were discussed.The optimal results were obtained at a reaction temperature of 180 ℃,a space velocity of 4 h-1,and a mole ratio of toluene to tert-butanol equating to 2.The structure and acidic properties of catalyst were characterized by the BET method and the Fourier transform infrared (FTIR) spectroscopy.Compared with the HY zeolite,the activated bentonite possessed high activity for toluene conversion and high para-selectivity because it had larger pore diameter,smaller micropore surface area and higher ratio of total Lewis acids to total Br nsted acids.

也谈应监甗

应监是监督殷遗民而非监督武庚,更非监督应国国君。在周王朝平定"武庚、管、蔡之乱"后,位于山西境内"武之穆(周武王之子)"的封国——应国,因其地邻近殷朝旧都安阳,而被周公与成王赋予监督殷遗民的新使命,"应监"可能是管蔡之乱后,应国国君应叔兼领监督殷遗民任务之时的称谓,南迁后的应国地处周王朝南疆,其国君仍然称为应侯,之所以称为应公者,则是因为他曾兼任周王室的卿士。

Iron-catalyzed aerobic oxidative amidation of tertiary amines with carboxylic acids

An oxidative amidation of tertiary amines with carboxylic acids has been developed in the presence of FeC13- 6H20 as catalyst and oxygen as oxidant. A variety of tertiary amides were obtained in good to excellent yields from inexpensive and readily available reagents. The possible reaction pathways were investigated.

SmI_2-promoted imino-Reformatsky reaction for facile synthesis of enantioenriched β-amino acid esters

A facile and efficient method for the stereoselective synthesis of β-amino acid esters via SmI2-promoted imino-Reformatsky reaction is described.Asymmetric addition of tert-butyl bromoacetate to N-tert-butanesulfinyl aldimines afforded β-amino acid esters in moderate to high yields with excellent diastereoselectivities.The synthetic utilities of the tert-butyl β-amino acid esters were expanded by the preparation of β-lactams and 3-aminoindan-1-ones derivatives.