Study On Isomerization Reaction Of Turpentine Catalyzed By Solid Acid

Camphene is widely applied to synthesize spice and medicament asimportant chemical material.At present,the main source of camphene is theisomerization of turpentine which is abundant in Guangxi Province.So it hasgreat significance to full use the rich turpentine resources by the study on theisomerization of turpentine in our country.The isomerization of turpentine respectively catalyzed by NH₄Y zeolite andNaZSM-5 zeolite had been studied and the followings were the main contentsand results.Firstly, study on the isomerization of turpentine catalyzed by different solidacid was carried out and the result showed that the isomerization of turpentinecould be catalyzed by NH4Y zeolite and NaZSM-5 zeolite respectively.Secondly, the relationship of the preparation condition of catalyst and theisomerization reaction was studied.That is,the effects of the cation exchange ofNaZSM-5 zeolite,roasting temperature and roasting time of NH₄Y zeolite andNH₄ZSM-5 zeolite on the isomerization reaction were discussed.The resultshowed that the best preparation condition of catalyst was that the NaZSM-5zeolite was cation exchanged by 0.3 mol/L NH4C1 solution and roasted at 400℃ for 2h,and the NH₄Y zeolite was roasted at 350℃for 2h.Thirdly, the reaction conditions,such as amount of catalyst,reactiontemperature and reaction time were optimized respectively.The results were asfollows:When the ratio of HY zeolite to raw material was 2.5g/100mL and thereaction was heated to 140℃for 4h,the effect of isomerization of turpentinewas better, the conversion rate of pinene was 97.02%,and the selectivity ofcamphene was 42.88%.When the ratio of HZSM-5 zeolite to raw material was4.5g/100mL and the reaction was heated to 140℃for 4h,the effect ofisomerization of turpentine was better, the conversion rate of pinene was86.24%,and the selectivity of camphene was 46.95%.Fourthly, the effect of trace water inreaction system on isomerization ofturpentine was studied.The result showed that whether the trace water was toomuch or too less,the conversion rate of pinene would decrease,while the changeof the selectivity of camphene was not obvious.Fifthly, the effects of the amount of a- pinene and B-pinene and oxidationof terpene on isomerization reaction were studied,which first elucidated that theoxide in raw material was the key factor to Counterwork isomerization of pinene.Sixthly, the effects of dealumination and modification of pore of the NH₄Yzeolite on isomerization reaction were studied.The results were as follows:Afterthe NH₄Y zeolite was dealuminated with Oxalic acid,the conversion of pinenespeeded up markedly, but the selectivity of camphene also dropped downmarkedly.After the NH₄Y zeolite was infused in solution of Mg(NO₃)₂,Zn(NO₃)₂ or Al(NO₃)₃ to remove corresponding oxide,the conversion rate of pinenedropped down,and the selectivity of camphene had little increase.Seventhly, the effect of reuse of HY zeolite on isomerization reaction wasstudied.The results were as follows:when the HY zeolite was used many timescontinuously, the conversion rate of pinene dropped down markedly, but theselectivity of camphene fell no more.The HY zeolite could be reused when itwas regenerated by carbon burning-off.