Processing Challenging Crudes – Enabled with Increased Hydrotreating Performance

Key to increasing refinery profitability in a low margin environment is the ability to take advantage of opportunity crudes. The challenge is effectively taking advantage of these difficult to treat feeds. This often requires increased process unit capability in different parts of the refinery depending on the particular feed, as well as the flexibility to offset the increase in processing requirements with the resulting changes in operational cycle lives.

LyondellBasell Houston Refining (HRO) has increased site-wide hydroprocessing capacity & capability, thereby ensuring production of clean fuels & enabling the processing of increasingly difficult crudes. Working with Criterion Catalysts (CC&T), to develop catalyst systems to suit these needs, HRO continued to incorporate & be on the forefront in use of newer catalyst technologies, such as CENTERA, for their operations. In 2010 with the processing of high sulfur, high nitrogen crudes, Houston Refining observed a number of impacts across the refinery, especially in the hydroprocessing units. One unit, a low-pressure kerosene hydrotreater which treats product to ultra low sulfur specifications, struggled to achieve its targeted two year cycle. The straight run kerosene feed had significantly increased in difficulty resulting in triple the normal catalyst deactivation rate, mainly due to much higher sulfur, nitrogen & aromatic content. As a result, unit turnarounds were required more often than normal.

This paper outlines how HRO & CC&T worked together to understand the variables & the cycle life impact of processing this opportunity feed. By bringing together expertise on the catalyst & refinery operations, they were able to fully restore the hydrotreater’s operational cycle & increase overall hydrotreating capability which enabled high margin feed processing without compromising reliable operations. Additional benefits were also evident & supported through test-runs which will allow for additional future flexibility in producing products in alternate modes of operation, either ULSD or Jet Fuel.