Study of effective parameters in the Fischer Tropsch synthesis using monolithic CNT supported cobalt catalysts

•Monoliths prepared from CNT supported cobalt catalyst have been evaluated for FTS.•Pressure affects the product selectivity more than T, GHSV and cobalt loading.•The CO conversion is highly affected by T in comparison with P, GHSV and Co%.•The effect of parameters interaction on conversion and selectivity is demonstrated.•Pressure augmentation increases CO conversion and heavier hydrocarbon production.

In this work monolithic catalysts have been prepared using carbon nanotubes as the support material. In order to screen the effective factors on CO conversion, C5+ selectivity and C1 selectivity, fractional factorial design method have been used. Considering temperature, pressure, Gas Hourly Space Velocity (GHSV) and cobalt loading as the four effective parameters, different runs have been designed for experiments. Quadratic models for CO conversion and product selectivity have been developed based on the experimental results. Furthermore, the analysis of variance (ANOVA) was implemented as a significant tool in order to evaluate the accuracy of the model. The ANOVA results of the developed model showed that they are significant with a 95% confidence limit. The main effective parameters have been declared for CO conversion, heavier hydrocarbon and methane selectivity. It is clear that the importance of parameters vary from one response to another. The interaction of parameters has been studied as well. The results demonstrate that temperature is the most effective parameters on CO conversion while its interaction with pressure is more important than other parameter interactions. Pressure affects C5+ and C1 selectivity more than other parameters whereas interaction of pressure with cobalt loading are the most effective interactions for these two responses.