Identification of final fuel matrix for engine testing and 3D-CFD simulations (Oct 2019 – Month 13/36)

Intermediate result from partner VKA-RWTH and OWI

Result has been achieved on 15 October 2019 in month 13 of the project.

REDIFUEL has to meet the EN590 norm for minimum Cetane Number (CN) of 51. Here, mainly two properties were considered: density and CN. While the density is an indicator of the volumetric energy content of the fuel, ensuring a similar CN as diesel guarantees not major modifications to engine calibration and hardware. The diesel used here is a standard diesel B0 w/o biofuel content. Different blends of surrogate alcohol mixture (SAM) with gas to liquid (GtL) of the RFA30P70 (i.e., 30 vol% alcohols mixed with paraffinic diesel) with diesel were screened with regards to their self-ignition tendency and density. This preliminary screening served to identify a drop-in blend compliant with the EN590 norm.

  • Objective: To identify a drop-in blend compliant with the EN590 norm for CN and density.
  • Research: The CN was determined experimentally using an Advanced Fuel Ignition Delay Analyzer (AFIDA) . The device measures the indicated cetane number (ICN) in a closed volume chamber under standard conditions, which matches the standard CN method. The density was measured in accordance with DIN EN ISO 12185:1996 with a Stabinger Viscometer (SVMTM 3001) at OWI.
  • Result: All the blends of B0 with RFA30P70 satisfy the minimum CN requirement of the EN590 norm. The RFA30P70 has a CN of ~ 57 and therefore all the different blending proportions with B0 diesel have a CN above 52 (measured CN for B0). (Fig 1). On the right-hand side of Fig 1, it can be seen that the density of the blends increases with an increasing share of B0 since diesel counteracts the low density of the REDIFUEL paraffines. The blend with 60 vol% B0 and 40 vol% RFA30P70 satisfies both the minimum requirement for CN and density stated by the EN590 norm. Thus, this blend was chosen for future engine testing and 3D-CFD simulation work.
  • What will it be used for: The results were shared with the partners to finalize the fuel matrix for further experimental and numerical investigations.
  • Impact: From the synergic analysis of both density and CN, a possible EN590 compliant REDIFUEL blend with diesel was highlighted. Hence, the other partners as well have also focused on analyzing this mixture in more detail. For example, a more detailed engine testing will be conducted on the heavy duty single cylinder at FEV Europe GmbH to exploit the potential for application in the demonstrator truck.

Figure 1: Indicated Cetane Number determination of blends of RFA30P70 with B0 diesel ((VKA-RWTH and OWI)