A new IFRF report “Biofuels devolatilization and char combustion characterization with the IPFR” has been published today.  The report describes the devolatilization and combustion behaviours of five biofuels with different origins (two wood pellets, a straw, a nut shell, a hydrolytic lignin) which were characterized using the IFRF’s Isothermal Plug Flow Reactor (IPFR).  The tests were performed within the EU co-funded BRISK project, focusing on research on second generation biofuels with particular interest in developing specific methodologies and testing different biofuels. 

The IPFR allows the combustion characterization of solid fuels in a temperature range between 900 and 1300°C, with a particle residence time between 10 and 1500 ms.  Devolatilization and char combustion can be tested separately, under both conventional and oxy-fuel conditions.

The samples collected from the IPFR undergo several laboratory analyses: proximate, ultimate, particle size distribution and ash composition.  In particular, conversion during devolatilization and char combustion is calculated according to the ash tracer method, which assumes the ash content to be inert through processes occurring in the IPFR.

This report provides an overall description of the IPFR and of the applied experimental procedures, with the required pre-treatments, the IPFR operation and experimental matrices, and the post-processing operations.  A more detailed and theoretical approach can be found in the recent IFRF report G27/y/01.

The tests determined sufficiently reliable conversion trends versus residence time and temperature, to be used for the calculation of kinetic parameters.  For each test, the uncertainty affecting the value of conversion was determined and taken into consideration to draw the error bars.  The error on the determination of the real ash content of the parent biofuel and of the IPFR products was found to be the controlling factor on the overall error, especially at low conversion levels.  Also the possibility of a loss of ashes occurring during the IPFR tests was taken into consideration, by applying a first-order ash loss kinetic model characterized by the same activation energy of devolatilization.

Finally, the results of the characterization of the five biofuels were compared.  The reactivity of the different fuels during devolatilization and char combustion, as well as the trends of conversion for tests performed under the same conditions were compared and correlated with the characteristics of the parent fuel.

All the results of the analyses performed on the samples collected from the IPFR are shown in five dedicated annexes.

A future report will be dedicated to devolatilization and char combustion kinetics for these biofuels.

In the frame of BRISK, different second generation biofuels are being characterized and specific methodologies developed and tested.  The data will be compared with the results obtained by other partners based on entrained flow conditions and discussed via a Round Robin process.

Researchers running entrained flow reactors or similar devices, and who are interested in performing tests on different biofuels and eventually in participating in Round Robin activities, can apply to use one of the several rigs available to Users via the BRISK Transnational Access process. 

Click here to browse the list of the BRISK partners.

IFRF had a dissemination role in a now completed EU project, DEBCO – DEmonstration of large scale Biomass Co-firing and supply chain integration. View the DEBCO website.