Preparation Of Acid Treatment Hangjin 2~# Clay Catalyst And Its Application In Turpentine Isomerization Reaction

Rosin as an important renewable resource,its deep processing products can be widely used in synthetic fragrances,medicine and fine chemicals,and the entire correlative industry has accounted for 10%of GDP.The rough machining products of rosin are gum rosin and turpentine,and relevant study of rosin is relatively well developed.Deep processing of rosin involves many catalytic reactions,such as esterification,isomerization,hydration,polymerization,disproportionation.The isomerization of turpentine can produce camphene,limonene and carene,which are mainly used in the synthesis of camphor,spices and terpene resin.At present,solid acid is mostly used in turpentine isomerization reaction.However,because of no corrosive effect in equipment caused by solid acid,because of its friendly to the environment,and because it is easily recyclable,many researchers try to use solid acid.However,solid acid is high in cost and easy to be deactivated,it is limited in its application in industry.Hangjin 2^#clay,which is abundant in reserves,easy for exploitation and low at price,belongs to compund aluminosilicate minerals.Currently,research on Hangjin 2^#clay focuses on adsorption of organic or inorganic pollutants and bleaching of colored substance,whereas the research on preparation of catalysis from Hangjin 2^#clay is still scarce.Hangjin 2^#clay used in turpentine isomerization is even much less,and research in regard of turpentine isomerization reaction in a fixed bed reactor has not been reported.This paper is about attempts of applying Hangjin 2^#clay to turpentine isomerization reaction,and a series of catalysts is made by Hangjin 2^#clay treated with sulfuric acid,hydrochloric acid and phosphoric acid respectively.The catalyst having been made is used in a batch reactor;the systematic observation of the influence of preparation conditions on the reactivity of the catalyst is carried out,and the optimum reaction conditions have been obtained.Based on this,tentative innovation is attempted:to try the reaction of turpentine in fixed bed reactor,and to determine the catalyst preparation conditions and reaction conditions.The catalysts were characterized by XRD、FTIR、NH₃-TPD、TG-DTA and the reasons for influencing its catalytic properties were discussed and stability of the catalyst was preliminary studied.Specific conclusions are mainly as the following:Two activated clay was obtained by using sulfuric acid and hydrochloric acid to treat HangJin 2^#clay respectively.By treating with water,catalytic activity of catalyst was increased.This may be due to water washing treatment to make the material elute off the surface of the catalyst,increase the specific surface,acidity and amount of acid.The suitable preparing condition of SO₄^2-/Hangjin 2^#clay was obtained as follows:acid leaching concentration is 1.5 mol·L^-1;kept stirring and reflowing for 4 hours at 90°C,and calcinated for 4 hours in the muffle furnace at 350°C.The optimum isomerization resction conditions were that reaction temperature is 150°C,reaction time is 3h,and the amount of the catalyst is 3%.Under this condition,the conversion of Pinene is 100%,and the selectivity of Camphene is 51.9%.The conversion of Pinene was similar（100%）in three parallel experiments,and catalyst repeatability was excellent.SO₄^2-/Hangjin 2^#clay was used in fixed bed reactor,and the catalysts preparing condition was that the acid leaching concentration is 3.0 mol·L^-1;kept stirring and reflowing for 4 hours at 90°C,and calcinated for 2 hours in the muffle furnace at 350°C.The optimum isomerization resction conditions were that reaction temperature is 185°C,the amount of the catalyst is 0.8 g,and the gas flow rate is 70 ml/min.Under this condition,the conversion of Pinene is 100%,and the selectivity of Camphene is 52.6%.