| Rosin and turpentine are the major products obtained from pine oleoresin of biomass resources by steam distillation.The main components of rosin are diterpane resin acids,and turpentine mainly consists of monoterpenes.The application of dehydroabietic acid and p-cymene,the main products of the catalytic intermolecular hydrogen transfer reaction,in medicine,pesticide,surfactant and fine chemicals are drawing more and more attention due to their unique molecular structures.However,the traditional methods for preparation of dehydroabietic acid and p-cymene own some disadvantages,such as high temperature,many auxiliary reactions,low selectivity,longer process flow,complex equipment resulted in more investments and the low concentration of dehydroabietic acid and p-cymene,which restrict their application in industry on large scale).In order to understand and overcome these problems,a novel method should be developed,and further investigation on catalytic intermolecular hydrogen transfer reaction ought to be carried out on the basis of reaction kinetics and mechanism.But owing to the fact that the deep processing of the forest products involves a large number of compounds and many reactions,there are few literatures on reaction kinetics for the catalytic intermolecular hydrogen transfer reaction of rosin, turpentine and pine oleorsin,so the developments of the basic theory on the reactions were hindered.In order to solve the bottleneck problems involved in the preparation of dehydroabietic acid and p-cymene,the catalytic intermolecular hydrogen transfer reaction of rosin,turpentine and pine oleorsin and the kinetics on this complex reaction system have been put forward systematically,the main results are as follow.Firstly,a novel experimental technique has been developed for the study of the kinetics of heterogeneous reaction system,and the problem involved in the investigation of the kinetics of heterogeneous reaction system at high temperature for material which crystallize readily and using solid as catalyst has been overcome.The lumping kinetic models for catalytic intermolecular hydrogen transfer reaction and catalytic isomerization-intermolecular hydrogen transfer reaction of rosin over Pd/C catalyst were established.Based on the reaction mechanism and characteristics,the lumped components of the complex reaction systems were defined and the reaction networks were proposed by structural group and approximate reaction kinetic theory according to the fundamental principles of lumping method.The lumping kinetic model for intermolecular hydrogen transfer reaction of abietic type, pimarenoic acid type,hydrogenated abietic type,hydrogenated pimarenoic acid type resin acid and dehydroabietic acid was set up,and the lumping kinetic model for isomerization and intermolecular hydrogen transfer reaction of neoabietic acid,palustric acid,abietic acid, pimarenoic acid type resin acid,hydrogenated abietic type resin acid,hydrogenated pimarenoic acid type resin acid and dehydroabietic acid have been established as well,and the activation energies were 111.39,108.76,97.35 kJ·mol-1for abietic type resin acid dehydrogenation and hydrogenation and pimarenoic acid type resin acid hydrogenation respectively,and the activation energies were 156.14,78.80,108.56,105.75,97.35 kJ·mol-1 for neoabietic acid isomerization,palustric acid isomerization,abietic acid dehydrogenation and hydrogenation and pimarenoic acid type resin acid hydrogenation respectively.The final results demonstrated that the lumping model could characterize the kinetic behavior of the complicated forest product reaction and predict the concentration distribution of the relative multi-products at the temperature of 543 K.Secondly,a novel method for preparation of p-cymene from turpentine over Pd/C-H2SO4 composite catalyst was presented,and a lumping kinetic model for catalytic isomerization and intermolecular hydrogen transfer reaction of turpentine has been established.The effects of the species and content of catalysts,the species and concentration of acid,reaction temperature and time on the reaction were investigated.The reaction conditions were optimized by uniform design method,and then the conversion rate of pinene and the yield of p-cymene were 99.03%and 61.82%,respectively.The(reaction)products were qualitatively and quantitatively analyzed by gas chromatography/mass spectrometry with data system (GC-MS)and chromatography(GC).It indicates that the synergetic catalytic reaction mechanism of turpentine over Pd/C-H2SO4 catalyst is made up of carbonium mechanism by the action of acidity centre and hydrogen transfer mechanism induced by metal centre,and the isomerization-intermolecular hydrogen transfer disproportionation of bicyclic terpene pinene (the main composition of turpentine)are the main reactions.The parallel and consecutive coupling reaction for isomerization and intermolecular hydrogen transfer is realized.As a result,the reaction time was reduced from 14 h to 8 h～10 h.After the effects of internal and external diffusions were eliminated,the component concentrations were acquired by tracking analysis with gas chromatography.The lumped components in the complex reaction system were defined and the reaction network was proposed based on the reaction process characteristics.The lumping kinetic model of monoterpene,monoterpene with p-methadien structure,isomerization monterpene,p-cymene and hydrogenation monoterpane has been established according to the fundamental principles of lumping method,and the activation energies for isomerization of monoterpene to form monocyclic monoterpene with p-methadien structure,dehydrogenation and hydrogenation of monocyclic monoterpene with p-methadien structure were 77.86,80.18,71.33 kJ·mol-1,respectively.The results turned out that the intrinsic kinetic model are in good agreement with experimental data.The rate of dehydrogenation to form p-cymene was fastest at the temperature of 393K and the selectivity of p-cymene in the reaction system was highest.Thirdly,a novel method for preparation of disproportionated rosin and p-cymene by catalytic intermolecular hydrogen transfer reaction from oleoresin was provided,and the lumping kinetic models for catalytic intermolecular hydrogen transfer reaction,as well as catalytic isomerization and intermolecular hydrogen transfer reaction of oleoresin over Pd/C catalyst have been established.The products of catalytic disproportionation were quantitatively and qualitatively analyzed by GC and GC-MS,and the competition mechanism of the intermolecular hydrogen transfer reaction was discussed.The results show that,during the intermolecular hydrogen transfer reaction of resin acids and turpentine,dehydrogenation is the main reaction accompanied by a little hydrogenation reaction,and its main products are dehydroabietic acid and p-cymene.Then a preliminary discussion on the mechanism has been carried out,and it shows that the resin acids in oleoresin undergo the intermolecular hydrogen transfer reaction,in which the dehydrogenation of resin acids is promoted by the solvent effect of terpenes.It also indicates that the main component of the turpentine in oleoresin, double ring monoterpene is converted into monocyclic ring monoterpene by ring-opening isomerization reaction,which then into p-cymene by catalytic dehydrogenation under acidic condition(the resin acids).The optimal reaction conditions were obtained by uniform design method,and then the contents of dehydroabietic acid and p-cymene in the disproportionation product are 89.45%(based on the acid material weight)and 61.76%(based on the neutral oil weight),respectively.According to the Chinese Standard of B72002-1984 for disproportionated rosin products,the quality indexes of the disproportionation products are higher than those of the standard for superfine disproportionated rosin.The results show that the superfine disproportionated rosin and high contents of p-cymene could be obtained using the novel process from oleoresin.Based on the reaction mechanism and characteristics,the lumped components of the complex reaction system were defined and the reaction networks were proposed by structural group and approximate reaction kinetic theory according to the fundamental principles of lumping method,and the lumping kinetic model for intermolecular and hydrogen transfer reaction of monoterpene,p-cymene,hydrogenated monoterpene, abietic type resin acid,pimarenoic acid type resin acid,hydrogenated abietic type resin acid, hydrogenated pimarenoic acid type resin acid and dehydroabietic acid were established,and the lumping kinetic model for isomerization and intermolecular hydrogen transfer reaction of bicyclic terpene,monocyclic terpene,palustric acid,neoabietic acid,abietic acid,pimarenoic acid type resin acid,p-cymene,hydrogenated monoterpene,hydrogenated abietic type resin acid,hydrogenated pimarenoic acid type resin acid and dehydroabietic acid have been established as well.The kinetic model parameters were estimated and the various activation energies were 103.97,133.82,112.22,159.08,172.75,113.96,83.05 and 141.65 kJ mol-1for bicyclic monoterpene hydrogenation and ring-opening isomerization,monocyelic monoterpene dehydrogenation,palustric acid isomerization,neoabietic acid isomerization, abietic acid dehydrogenation,abietic acid hydrogenation and pimarenoic acid type resin acid hydrogenation,respectively.The final results demonstrated that the lumping model could characterize the kinetic behavior of the complicated forest product reaction and predict the concentration distribution of the multi-products at the temperature of 533 K.Based on the results of kinetics,it showed that dehydrogenation was main reaction during intermolecular hydrogen transfer reaction of oleoresin,and the reaction rate of the resin acids was faster than that of turpentine.
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