Evaluation of Sulfate Trapping Candidates-Results From Dynamometer and Vehicle Screening Tests

The performance of potential sulfate sorbents was evaluated using an engine-dynamometer screening test procedure. Bulk and supported sorbents were tested.

The two most promising sorbents were a bulk CaO preparation and alumina supported Na. The CaO sorbent appeared to be inherently non-selective between sulfates and SO₂. Calcining this sorbent in a CO₂ atmosphere resulted in increased pellet crush strength and reduced volume expansion upon use. The Na/Al₂O₃ sorbent had good activity and selectivity, but may lack capacity and be subject to leaching losses of Na-compounds.

Vehicle and dynamometer durability testing of these two sorbents was conducted. From these preliminary tests, it was determined that neither met all the criteria of an ideal sorbent for vehicle use.