Parameters influence establishment of the petroleum coke genesis on the structure and properties of a highly porous carbon material obtained by activation of KOH

Low-quality sulfur petroleum coke usually not widely qualified for use and is stockpiled at refineries around the world or used as solid fuel. One of the promising uses of low-quality petroleum coke is its physical or chemical activation in order to obtain a highly porous carbon material that can be used as a catalyst carrier, adsorbent, the basis for capacitive electrodes. In this work, four types of hydrocarbon which differ in origin, group hydrocarbon composition and properties, were used for petroleum coke production (vacuum residue, asphalt, heavy catalytic gasoil, heavy shale oil). In order to experimentally simulate the process of coke production was used a laboratory delayed coking unit with varying process parameters from 1.5 to 3.5 atmg at a temperature of 500 degrees C. The produced coke was subjected to chemical activation with KOH at 750 degrees C. Regularities of changes in the composition, structure and properties of coke produced with the examined raw materials at the typical regime parameters of the coking process during activation were studied by XRF, SEM, FT-IR spectroscopy, BET. It was shown that after activation the crystallinity of the coke and the mass of sulfur in the samples decreases, but increases the content of potassium. The largest surface area of 2302 m(2)/g and porosity 83% was obtained when using coke from vacuum residue at 1.5 atmg as a carbon feedstock for the activation process. In order to obtain a highly porous material it is necessary to use raw materials with less aromatic compounds, but containing comparable amounts of resins and saturated hydrocarbons.

Automated summary

Low-quality sulfur petroleum coke can be activated to obtain highly porous carbon material for various applications. By using a laboratory coking unit and chemical activation with KOH, the properties of the produced coke were studied. It was found that using coke from vacuum residue as a carbon feedstock resulted in the highest surface area and porosity.