The present invention aims to address the limitations of existing technology, such as small reaction scale, inability to achieve industrial continuous production, and complex treatment process. To overcome these shortcomings, the present invention provides a method and device for the continuous production of 4-Isopropyltoluene. This method offers continuous production, simple operation, and eliminates the need for waste, solvents, and other reaction reagents. Additionally, the catalyst used in this method is simple and recyclable.
The method for continuous production of paracymene involves loading 0.1kg to 50.0kg of Pd/C catalyst into the reactor and introducing it at a speed of 0.01L/min to 5.00L/min using an inert carrier gas like nitrogen. The heating device is turned on and the reactor temperature is raised to a range of 150°C to 400°C. Subsequently, the metering pump is activated and industrial dipentene is continuously fed into the reactor at a rate equivalent to a space speed of 0.5h-1 to 5.0h-1. The raw materials are preheated, gasified, and then come into contact with the catalyst. As the reaction progresses, the reaction products continuously enter the condenser connected to the bottom of the reactor. After condensation, the products are directly collected in a storage tank. The obtained product is paracymene. The Pd/C catalyst used in this method has a palladium content ranging from 0.1%wt to 10.0%wt.
The device used to implement the continuous production of 4-Isopropyltoluene consists of a raw material storage tank, a metering pump, a preheater, a gasifier, a reactor, a condenser, a product storage tank, and a heating device. A metering pump capable of continuous constant flow feeding is placed between the preheater and the raw material storage tank. The inlet of the metering pump is connected to the outlet of the raw material storage tank, and the outlet of the metering pump is connected to the inlet of the preheater. The outlet of the preheater is then connected to the inlet of the gasifier. The outlet of the gasifier is connected to the inlet at the top of the reactor. The outlet at the bottom of the reactor is connected to the inlet of the condenser, and the outlet of the condenser is connected to the inlet of the product storage tank. The preheater, gasifier, reactor, and heating device are all interconnected. The vaporizer contains a nozzle with an inner diameter ranging from 0.05mm to 1.00mm. The reactor is a tubular reactor with tubes loaded with reaction catalysts. It is equipped with a temperature sensor and a jacket for temperature control. The reactor is a tubular multi-tube reaction bed, and the reactor jacket can regulate the temperature. The feed port of the reactor is located at the top, and the raw materials are preheated, atomized, and gasified by the nozzle before entering the reaction bed from the top. The reaction product exits the reactor from the bottom and is collected directly into the product storage tank after condensation. The heating device comprises an expander, a magnetic pump, a cold oil tank, and a hot oil furnace. A magnetic pump is placed between the cold oil tank and the hot oil furnace, which is connected to the preheater, gasifier, and reactor. One end of the hot oil furnace is connected to the expansion tank, while the other end is connected to the preheater, gasifier, and reactor, forming a closed heating loop with the magnetic pump.
The raw material used in this invention, industrial dipentene, is a monocyclic terpene with a six-membered ring structure. It can be converted into 4-Isopropyltoluene through catalytic dehydrogenation. Industrial dipentene is a mixture of monocyclic monoterpenoids with similar molecular weight and structure, and it usually contains various isomers such as limonene, α-terpinene, α-phellandrene, β-phellandrene, γ-terpinene, and terpinene.