• ‘Reigniting the…Solid Fuel Database’

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      Jarek Hercog

Following on from contributions to our ‘Reigniting the…’ series in January and February from former IFRF Director Neil Fricker and former Investigator Giovanni Corraggio (looking back to the key IFRF activities and outputs of the 2010-2016  period and the 2000s respectively), this month is different…  In this article, former IFRF Investigator Jarek Hercog of IEN in Poland is our guide as we now look back at a specific topic – the creation of the IFRF’s Solid Fuel Database.

Reigniting the… Solid Fuel Database – a perspective from Jarek Hercog, former IFRF Investigator

Hello everyone!  This is Jarek Hercog writing about the next part of the IFRF story as we travel back in time from the present day to IFRF’s beginnings, i.e. the development of the Solid Fuel Database and the associated fuel characterisation activities at IFRF.

My adventure with IFRF began in 2007, when I arrived in Livorno to work and enjoy the best time of the year in Italy: October to March 😉 [Editor – well, Jarek is from Poland…!]

The first task that I was assigned to by Leo Tognotti, the IFRF Director at that time, was to define the structure for, and develop the content of a new database that would gather together all the extensive fuel characterisation data collected through the long research history of IFRF.

The objectives for this new database were:

  • to provide data for enhancing combustion flexibility;
  • to predict the properties of new or surrogate fuels;
  • to enable the defining of computationally-feasible CFD sub-models; and
  • to provide detailed data for advanced model development.

The main source of data was the IFRF archive, but it was in a number of different forms: printed reports, PDF files, spreadsheets, and even text documents.

During the IJmuiden period of IFRF’s history, many outstanding fuel characterisation campaigns had been undertaken in conditions that, even today, would be hard to meet, e.g. a drop-tube furnace wall temperature of 1550°C.

For example, in the 1980s, a suite of various coals had been characterised in the old Isothermal Plug Flow Reactor (IPFR) in IJmuiden, with experimental results on devolatilisation and char oxidation collated in two exceptional reports:

  • Characterisation of the combustion performance of a suite of pulverised coals: Report on CC1 trials (Morgan and Decker) –IFRF Doc. No. F 88/a/4, 1987; and
  • Development of combustion characterisation technique for high volatile bituminous coals: Report on CC4 investigations (Morgan et al) – IFRF Doc. No. F 88/a/10, 1989.

Over the years, a number of solid fuels were characterised for devolatilisation, char oxidation and nitrogen release, both for scientific and commercial purposes.  On this basis, several mathematical models were developed which are still used today in numerical simulation of combustion systems, e.g. the IFRF97 reaction rate model for char conversion, described here:

  • Pulverised fuel combustion characterisation of fuel blends: Final report on CC10 Experiments (Van de kamp et al) – IFRF Doc. No. F 37/y/38, 1996.

A vast amount of collected data finally found its place in the online Solid Fuel Database, which now consists of characterisation data for almost 300 different fuel samples – coal, biomass, sludge, waste and blends.  This gives almost 300 sets of devolatilisation data, 500 sets of char oxidation data and 50 sets of nitrogen release data.

These data are supplemented with proximate and ultimate analyses, calorific values, densities, particle sizes, petrographic analyses, ash composition analyses, fusion temperatures, and so on – valuable information that can be used for developing mathematical models, CFD modelling, and designing burners and combustion systems.  Moreover, the significant advantage that the SFDB has over other fuel databases available online is that the geometrical characteristics of the experimental rigs used, together with the particular operating (boundary) conditions of the experiments, have been presented to enable the meaningful use of such data by designers and modellers.  Also, the SFDB can be very useful when the crucial sub-model parameters of a particular fuel are missing – one can look-up relevant parameters for a similar fuel.

More details about all the data gathered in the SFDB can be found here:

  • Realisation of IFRF Solid Fuel Database Phase 1 (Hercog) – IFRF Doc No E 36/y/02, 2008.

Moreover, the common characterisation procedures that were used to standardise the data were described in detail in this report:

  • Review of methodologies for coal characterisation (Biagini and Marcucci) – IFRF Doc. No G 03/y/01, 2010.

This report also includes a review of the different techniques and apparatuses adopted for devolatilisation and char oxidation tests, together with a critical assessment in relation to their practical applications.

Thanks to the ‘search’, ‘compare’ and ‘export’ features of the database, analysis of the large volume of data is possible.  This can be used for finding missing data required for numerical modelling, such as kinetic parameters, but also enables the development and testing of one’s own models.  For example these features were used to test the one-parameter model for char oxidation, the work being subsequently published in the journal Energy & Fuels:

  • One-parameter model for the oxidation of pulverised bituminous coal chars (Karlstrom et al) – Energy & Fuels, vol.26, p.968-975, 2012.

And that’s not the end of the story – in recent years new data arising from international R&D projects have been acquired and added to the SFDB.

Thank you for reading and I look forward to seeing you in the SFDB!

Zalaczam pozdrowienia, [Editor – apologies to our Polish friends for the lack of Polish letters, our website just can not cope with them at the moment!]

[Editor – thanks Jarek, and “best regards” to you too!  This was a really useful reminder to us all of what a valuable data resource we have available to us in the shape of the Solid Fuel Database.  We look forward to seeing you as one of the speakers at our IFRF 2018 Conference in Sheffield in 10 weeks’ time.]