Process for producing at least one product from at least one gaseous reactant in a slurry bed
A process for producing at least one product from at least one gaseous reactant includes feeding the gaseous reactant, as a gaseous feed or as part of a gaseous feed which is at an inlet superficial gas velocity of at least 0.5 m/s, into a vessel holding an expanded slurry bed of solid catalyst particles suspended in a suspension liquid so that the gaseous reactant can bubble upwardly through the slurry bed. The slurry bed has a catalyst loading of at least 20% by volume of degassed slurry. The gaseous reactant is allowed to react catalytically at a pressure above atmospheric pressure as the gaseous reactant bubbles upwardly through the slurry bed to produce at least one product. The product and any unreacted gaseous reactant are withdrawn from the vessel.
1. A process for producing at least one product from at least one gaseous reactant, the process including
feeding said at least one gaseous reactant, as a gaseous feed or as part of a gaseous feed which is at an inlet superficial gas velocity of between 0.5 m/s and 2.5 m/s, into a vessel holding an expanded slurry bed of solid catalyst particles suspended in a suspension liquid so that the gaseous reactant can bubble upwardly through the slurry bed, the slurry bed having a catalyst loading of between 20% and 55% by volume of degassed slurry, the slurry bed operating in churn-turbulent flow regime, wherein a volumetric mass transfer coefficient for gas-liquid transfer is above 0.2/s;
allowing said at least one gaseous reactant to react catalytically at a pressure above atmospheric pressure as the gaseous reactant bubbles upwardly through the slurry bed to produce said at least one product, without the reaction becoming mass transfer controlled; and
withdrawing said at least one product and any unreacted gaseous reactant from the vessel.
2. The process as claimed in claim 1 , in which the gaseous feed includes at least CO and H 2 as gaseous reactants, and in which the gaseous feed is fed into the slurry bed to produce liquid and gaseous hydrocarbons, with the catalyst being a hydrocarbon synthesis catalyst.
3. The process as claimed in claim 2 , in which the volumetric productivity of the process (the space-time yield of the process) is above 1500 kg total hydrocarbons/(m 3 gas expanded slurry bed·day).
4. The process as claimed in claim 2 , in which the catalyst is a cobalt catalyst and wherein the process is operated at a synthesis gas per pass conversion of at least 40 mol %.
5. The process as claimed in claim 1 , in which the catalyst loading is at least 30% by volume of degassed slurry.
6. The process as claimed in claim 5 , in which the catalyst loading is at least 35% by volume of degassed slurry.
7. The process as claimed in claim 1 , in which the inlet superficial gas velocity is at least 0.6 m/s.
8. The process as claimed in claim 7 , in which the inlet superficial gas velocity is at least 0.7 m/s.
9. The process as claimed in claim 8 , in which the inlet superficial gas velocity is at least 0.85 m/s.
10. The process as claimed in claim 1 , in which the expanded slurry bed has a height of less than 40 m and a diameter of at least 6 m.