Catalyst deactivation in two-stage coal liquefaction

An assessment was made of the performance and deactivation characteristics of catalysts used in the hydroprocessing reactor at the Wilsonville Advanced Coal Liquefaction Test Facility. Spent catalyst samples were collected periodically during 3 test runs. The samples were characterised by various analytical techniques and subjected to a batch activity test. All catalyst samples showed similar declines in specific pore volume, specific surface area and average pore diameter. Although the carbon concentration reaches equilibrium very quickly, the atomic H/C ratio decreased throughout the runs. Deposition of trace metals on the catalyst increased continuously throughout the runs, but at a decreasing rate.