A method for preparing carbon nanotubes from waste tires

Abstract

The invention provides a method for preparing carbon nanotubes using waste tires as a carbon source. The catalyst and waste tire particles are uniformly mixed; placed in a quartz boat in a high-temperature tubular resistance furnace, fed with nitrogen, and then heated to 700-900 ℃, and finally cooled to room temperature, then took out the crude product; ground it into powder, added nitric acid to dissolve it, and after ultrasonic treatment, stirred at a constant temperature in an oil bath at 90-120°C; filtered and washed the solution to pH 6.8-7.2, and Dry the obtained precipitate in an oven overnight, take it out and put it into a muffle furnace and raise the temperature to 500-700° C. to keep it warm; then cool it to room temperature and take it out to obtain purified carbon nanotubes. The method is simple to operate, and the yield of the prepared carbon nanotubes can reach more than 30%, which is conducive to the development of carbon nanotubes in the direction of production and high purity; realizes the high-value utilization of waste tires, and has great economic value and social value. benefit.

Description

technical field [0001] The invention relates to a method for preparing carbon nanotubes, in particular to a method for preparing carbon nanotubes by using waste tires as raw materials. Background technique [0002] With the development of the automobile industry, my country's demand for rubber products such as tires is also increasing. At the same time, the production of scrap tires has also increased dramatically. According to incomplete statistics, in 2013, my country's waste tires reached 299 million, with a weight of 10.8 million tons, and the annual growth rate was 8-10%. At present, the treatment methods of waste tires include direct utilization, retreading of old tires, production of rubber powder, generation of reclaimed rubber, combustion utilization, and pyrolysis utilization. Among them, pyrolysis technology has received high attention at home and abroad. In recent years, domestic and foreign scholars have carried out in-depth research on waste tire pyrolysis te...

AI Technical Summary

Problems solved by technology

At present, due to technical reasons, carbon nanotubes cannot be really applied in industrial production. The reason is that high-quality carbon nanotubes cannot be mass-produced continuously, the purity of the prepared carbon nanotubes is not enough, and the influencing factors in the preparation process More (such as the metal catalyst residue used, the raw materials used to prepare carbon nanotubes, the temperature during preparation, etc.)

Some studies have used noble metals as catalysts to prepare carbon nanotubes, but this method is too expensive to prepare carbon nanotubes on a large scale

At present, there is a method for preparing carbon nanotubes by pyrolysis of biomass and waste tires (see Shen Boxiong, Liu Lijun, Wu Hanming. A method for producing hydrogen and carbon nanotubes by pyrolysis of waste tires and biomass), and the catalyst used by Al 2 o 3 The carrier uses single metal NiO as the catalyst. This method requires strict technology and complicated operation, and the yield of carbon nanotubes is not high, and only 20% of the yield of carbon nanotubes is obtained.

It is also mentioned in the literature (see Zhang Y, Wu C, Nahil M A, et al. 3334.) Using waste tires as raw materials, single metal Ni / Al 2 o 3 As a catalyst, the introduced steam also affects the structure of carbon nanotubes, and the yield of prepared carbon nanotubes is not high, and there are too many impurities

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