Up until 24th October 2017 the soot particulate filter had always been referred to on the forum as the "DPF". Then I received "the letter" from the Executive Board with this statement: "The SCRF (Selective catalytic reductant filter) component was inspected and soot was found on the rear face. This component contains the diesel particulate filter." Initially this statement made no sense to me, and subsequently I mis-identified the SCRF component as the DOC: https://www.discosportforums.co.uk/viewtopic.php?f=8&t=5379&p=76180&hilit=SCRF#p76180
Since then every time I have searched the web for "SCRF" at least one of the results has it written SCRF® implying that these devices contain protected intellectual copyright material. Trying to get to the bottom of this, today I found a scientific paper called "A Study of the Soot Combustion Efficiency of an SCRF® Catalyst vs a CSF During Active Regeneration" by Lasitha Cumaranatunge et al. The abstract immediately caught my attention:
The soot combustion efficiency of a Pt-based catalyzed soot filter (CSF) was compared to a Cu-SCR catalyst-coated soot filter (SCRF® catalyst) under active regeneration conditions. The CSF was found to have a significantly higher soot combustion efficiency compared to the SCRF® catalyst under typical active regeneration conditions (550-600 °C). Despite the thermodynamic equilibrium limitation of the NO oxidation reaction at high temperatures and the relatively small quantity of NOx in diesel exhaust compared to O2, there is sufficient NO2 production capacity in a CSF where the impact of NO2 to the overall soot combustion efficiency under active regeneration conditions is significant. The differences between a standard porosity filter typically used for a CSF vs a high-porosity filter used for an SCRF® catalyst can only account for a minor portion of the difference in the soot combustion efficiency observed between the CSF and SCRF® catalyst. The fast consumption of the NO2 produced in situ in the CSF by soot may be driving the thermodynamic equilibrium of the NO oxidation reaction to continuously produce more NO2 for further soot combustion during active regeneration, resulting in a significant increase in the soot combustion efficiency in a CSF compared to an SCRF® catalyst or an uncoated filter.
If the JLR component referred to in the letter actually does employ SCRF® technology, this opens up a new avenue of possibilities regarding the root cause for the unfathomably poor performance of the DPF and (with the glass decidedly half-full, to coin a phrase) maybe it points to the possibility of an early hardware fix. Any ideas?
Since then every time I have searched the web for "SCRF" at least one of the results has it written SCRF® implying that these devices contain protected intellectual copyright material. Trying to get to the bottom of this, today I found a scientific paper called "A Study of the Soot Combustion Efficiency of an SCRF® Catalyst vs a CSF During Active Regeneration" by Lasitha Cumaranatunge et al. The abstract immediately caught my attention:
The soot combustion efficiency of a Pt-based catalyzed soot filter (CSF) was compared to a Cu-SCR catalyst-coated soot filter (SCRF® catalyst) under active regeneration conditions. The CSF was found to have a significantly higher soot combustion efficiency compared to the SCRF® catalyst under typical active regeneration conditions (550-600 °C). Despite the thermodynamic equilibrium limitation of the NO oxidation reaction at high temperatures and the relatively small quantity of NOx in diesel exhaust compared to O2, there is sufficient NO2 production capacity in a CSF where the impact of NO2 to the overall soot combustion efficiency under active regeneration conditions is significant. The differences between a standard porosity filter typically used for a CSF vs a high-porosity filter used for an SCRF® catalyst can only account for a minor portion of the difference in the soot combustion efficiency observed between the CSF and SCRF® catalyst. The fast consumption of the NO2 produced in situ in the CSF by soot may be driving the thermodynamic equilibrium of the NO oxidation reaction to continuously produce more NO2 for further soot combustion during active regeneration, resulting in a significant increase in the soot combustion efficiency in a CSF compared to an SCRF® catalyst or an uncoated filter.
If the JLR component referred to in the letter actually does employ SCRF® technology, this opens up a new avenue of possibilities regarding the root cause for the unfathomably poor performance of the DPF and (with the glass decidedly half-full, to coin a phrase) maybe it points to the possibility of an early hardware fix. Any ideas?