(617dc) Scale up Study of Fischer Tropsch Synthesis Reactor with Reduced CO2 emissions Using Cu-K Promoted Silica Supported Fe Catalyst

Fischer Tropsch Synthesis (FTS) is a technology to produce liquid fuels from syngas (mixture of H₂ & CO obtained from coal, petcoke and biomass) as an alternate to crude oil. However, the quantity of emitted CO₂ from the FTS is one of the serious disadvantages of the process. Choice of operating parameters of reactor is one of the methods for reduction of CO₂ emissions from FTS. Parametric studies were conducted in a once through fixed bed reactor with mixture of H₂ and CO in a temperature range of 215-245^OC, the pressure range of 5-25 bar, the space velocity range of 1000-4000 cc/g cat/h and a H₂/CO feed ratio of 0.7/1â??3/1 (mol/mol) to investigate the influence of the above process parameters on the performance of in-house developed Cu-K promoted silica supported Fe based catalyst in terms of its hydrocarbon & CO₂ formation rate, selectivity of olefins to paraffins, liquid hydrocarbon product distribution and properties.

The reaction rate, one of the most important parameters, plays a significant role in scale up of FTS reactor and industrial design. It was observed that FTS reaction rate (hydrocarbon formation rate) increased with increase in temperature, pressure and GHSV. However, FTS reaction rate passed through optimum with increase in H₂/CO feed ratio from 0.7/1â??3/1 (mol/mol). CO₂ formation rate (Water Gas Shift activity rate) increased with increase in temperature and GHSV, while decreased with increase in pressure, H₂/CO molar ratio. With increase of temperature and space velocity, selectivity of olefins to paraffins increased while the reverse was observed with increase in pressure and H₂/CO molar ratio. Further, liquid hydrocarbon product distribution, chain growth probability and properties were investigated on the basis of liquid products collected after completion of 1000 h run at the above operating domain. The experimental results show that the chain growth probability and liquid product properties depend on operating conditions as well as composition of catalyst. From the above analysis, the optimum operating conditions for higher hydrocarbon formation and lower CO₂ formation rate of developed Cu-K promoted and silica supported Fe based catalyst are identified for scale up to industrial reactor. This is done in order to explore the prospect of obtaining higher amount of synthetic crude fuel & lighter olefins products that can be integrated into existing refineries & petrochemical complex, in line with the main aims and objectives of the project.