Study on high temperature pyrolysis process and sulfur transformation property of high sulfur petroleum coke

In order to understand the pyrolysis process and sulfur transformation property of high sulfur petroleum coke at high temperature, the pyrolysis experiment of Qingdao high sulfur petroleum coke at high temperature (900-1500℃) was carried out in a high temperature fixed bed. The release rule of pyrolysis gas and the evolution of physical pore structure and chemical characteristics of coke during pyrolysis were investigated. At the same time, the content and existing mode of sulfur in the samples before and after pyrolysis were studied. The results show that with the increase in pyrolysis temperature, the content of H₂ in the pyrolysis gas of petroleum coke increases gradually; the content of CO changes little; while the content of CH₄ and CO₂ decreases gradually. Moreover, as the pyrolysis temperature is increased, the specific surface area and average porosity of pyrolysis coke increase; the surface morphology of particles is less affected; the content of amorphous carbon in petroleum coke reduces; and the order and graphitization degree of microcrystalline structure increase gradually. However, with the increase in pyrolysis temperature, the gasification activity of pyrolysis coke is first decreased and then increased, with the minimum value around 1100℃. It is found that the sulfur release rate in high sulfur petroleum coke pyrolysis at 1500℃ reaches 81.34%, and only a small amount of organic sulfur in the form of mercaptans and thiophene rings is retained in solid.