Journal of Petroleum & Environmental Biotechnology

Cobalt-based catalyst supported on modified shungite for Fisher-Tropsch synthesis

5^th World Congress on Petrochemistry and Chemical Engineering

December 05-07, 2016 Phoenix, USA

B T Ermagambet, L D Abylgazina and A V Kholod

Institute of Coal Chemistry and Technology, Kazakhstan

Posters & Accepted Abstracts: J Pet Environ Biotechnol

Abstract:

Fischer-Tropsch synthesis (FTS) converts synthesized gas into hydrocarbons, environmentally clean and free of sulfur, nitrogen, aromatic compounds, and heavy metals in the presence of a catalyst. It is well known that the properties of the catalyst support, such as specific surface area, porosity among others are important factors in obtaining high dispersion particles. Generally, the supports used for cobalt catalysts are Al2O3, TiO2 and SiO2. Their main disadvantage is their interactions with the metal that results in the formation of the hybrid compounds witch results in the loss of their catalytic activity, moreover, they have a very high temperature of reduction. One way of overcoming this problem is the use of carbon supports, which have a weak interaction with metals. In this work we developed new catalytic system for FT-synthesis, using modified Shungite as support. Firstly, modification of pristine shungite was carried out by treatment with sodium hydroxide, hydrochloric acid and perchloric acid to remove aluminosilicate, silicate components, and metal oxides. Then shungite was impregnated with aqueous solution of cobalt nitrate Co(NO3)2, dried in air at 100ºC and calcined at 900ºC. The morphology and microstructure of pristine shungite particles, as well as the supported co-catalyst were observed by using a scanning electron microscope JEOL7500F at an accelerating voltage of 5.0 kV. SEM image of synthesized catalyst shows that the particle size of cobalt deposited on the modified shungite ranged between 100 and 300 nm. After modification and impregnation of the carbon support has acquired more uniform structure. EDX analysis showing the following elemental composition of catalyst (wt.%): O42.79; C17.79; Si22.98; Al16.35; and Co4.09. This analysis confirmed that in the course of modifying, shungite changed its elemental composition, i.e. the undesirable components have been removed. Catalytic tests on the obtained co-catalyst powder were conducted using a laboratory setup FT synthesis flow type under atmospheric pressure without catalyst reduction. The synthesis was carried out in the working environment of a mixture of H2 and CO with a volume ratio of 3/1 at a temperature range of 200 to 440ºC and at a space velocity of 1500 hr1 (volume flow rate 5 cm3/s). The analysis of the gaseous and liquid products was carried out by gas chromatography apparatus Kristallyuks4000 and GC1000 chromos. It showed the formation of hydrocarbons C1C 4, C5+, the formation of which takes place predominantly in the direction of obtaining methane CH4. The maximum output CH4 was observed at a relatively high temperature of 350ºC. Further increase in temperature led to a decrease in the concentration of methane. Thus, a new cobalt based catalyst supported on modified shungite was presented. The material exhibits active properties and allow to obtain synthetic hydrocarbons namely C1C 4, C5+ under atmospheric pressure. This material can be used in the process of methanation of synthesis gas to produce a methane rich fuel gas. Since modified shungite provides a large surface area and high dispersion of the catalyst, it can be used as a promising support in catalysis applications.

Biography :

Email: lelya_1501@mail.ru