The Research Of The Influence Of Pyrolysis And Metal On Petroleum Coke Gasification Reactivity

Four petroleum coke and typical coals (zunyi anthracite coal, shenfu bituminous coal and Inner Mongolia lignite coal) were chosen as the object of research. The relationship between the structure and gasification were investigated and how to improve the gasification reactivity of petroleum coke were solved. The changes of petroleum coke structure during gasification process were investigated and changes in structure and gasification reactivity of petroleum coke and coal upon pyrolysis were studied. Effect of inorganic salt catalyst, shenhua coal direct liquid residue, biomass ash and oily sludge on gasification reactivity of petroleum coke was studied. The catalytic mechanism of metallic catalyst was investigated in detail. The investigation about petroleum coke modified upon microwave treatment to improve gasification reactivity of petroleum coke was made, and gasification model was established. The main contents and results were summarized as follows:(1) Microcrystalline structure, pore structure and functional group of petroleum coke and coal were compared. At normal atmosphere and 950～1380℃, CO2 and H2O gasification reaction kinetics of petroleum coke and coal by isothermal thermo-gravimetry were studied. Influence of coal, temperature, gasifying agent, partial pressure on gasification reactivity and the changes of petroleum coke structure during gasification process were investigated.(2) Effect of pyrolysis on the structure and gasification reactivity of petroleum coke was studied. Petroleum coke slow pyrolysis char, petroleum coke and coal rapid pyrolysis char and petroleum coke char water slurry rapid pyrolysis char were prepared. The factors such as pyrolysis temperature, heating rate, feeding in mode on the structure and gasification reactivity of petroleum coke were investigated. The gasification reactivity of rapid pyrolysis petroleum coke char was better than slow pyrolysis petroleum coke. The experimental results showed that gasification reactivity of slow pyrolysis petroleum coke char decreased gradually with increase of pyrolysis temperature, and the reactivity of rapid pyrolysis petroleum coke char firstly increased, and then decreased. The petroleum coke water slurry char increased gradually.(3) The factors which influence the catalytic effect of potassium salt, calcium salt and ferrous salt metallic catalyst, such as loading, mode of loading, anion cation kind and gasification temperature, were studied. The catalytic mechanism of metallic catalyst, binary catalyst and three-way catalyst were investigated. Results show that the temperature and loading were the main factors influencing metallic catalyst. The catalytic effect was better with increase of gasification temperature, and an optimal loading exist. Potassium salt catalyzed petroleum coke by changing energy on the char surface. Calcium salt and ferrous salt catalyzed petroleum coke by oxidation-reduction circular reaction.(4) Effect of additive loading, component and temperature on gasification of petroleum coke during co-gasification of petroleum coke and shenhua coal direct liquid residue and biomass were investigated. The carbon structure and minerals component were studied for elaborating mechanism of activation. Results show that the oil content and asphaltine in shenhua coal direct liquid residue had no catalytic effect on gasification of petroleum coke, and the alkali and alkali-earth metal and sulphur-iron series catalyst during coal liquification process were the main factors influencing gasification reactivity. The characteristic of biomass ash and the effect on gasification of petroleum coke were investigated and an influence factor index was raised. Relationship between catalytic effect and metallic ion kind of biomass ash were established.(5) Modified petroleum coke by microwave. Effect of microwave irradiation parameters and medium on microcrystalline structure, pore structure and functional group of petroleum coke were investigated and the gasification reactivity of modified petroleum coke was analyzed in TGA. With the further extension of microwave irradiation time and increase of microwave irradiation power, the crystalline structure of petroleum coke tended to amorphous state, and the proportion of mecropore and macropore increased, the proportion of micropore decreased. With the increase of microwave irradiation temperature, the crystalline structure first decreased, and then increased. The pore volume and surface area of mecropore and macropore reached a maximum at 388K. In a word, microwave irradiation improve the gasification reactivity of petroleum coke to a certain degree, and the gasification reactivity of microwave treated petroleum coke in alkaline medium than that in neutral medium.