Monday, 16 February 2015

Xinyan Huang wins Qatar Petroleum Medal for research on Clean Fossil Fuels

I am delighted t announce that my PhD student Xinyan Huang, working on peat fires, has been awarded the Qatar Petroleum Medal for PhD Research Excellence in Clean Fossil Fuels.
Xinyan (center) receives the QP Medal from Dr Naji Saad
during the award dinner at 170 Queens Gate.
Prof Blunt is to his left.

Xinyan wearing the QP Medal and the happy supervisor.

 The Press Release from Imperial reads:  

The Qatar Petroleum Medal and Prize for Research Excellence in Clean Fossil Fuels is awarded annually to a PhD student at Imperial College London who is in their third or fourth year of study. Sponsored by Qatar Petroleum, through the Qatar Carbonates and Carbon Storage Research Centre (QCCSRC), the award is to recognise their outstanding achievements in the field of Clean Fossil Fuels.

This year’s prize of £1000 and a commemorative medal has been awarded to Xinyan Huang from the Department of Mechanical Engineering. In a field of very strong candidates, it was his achievements in research and his publication record that impressed the judges. “Xinyan has been a fantastic student since he started here in 2012, it is a joy to work with someone like him who can seamlessly combine experiments and modelling to answer scientific questions” says Dr Guillermo Rein (that is me!), Xinyan’s PhD supervisor “I think this award recognises that he has been a valuable member of the engineering community both here at Imperial but also in the wider Clean Fossil Fuels field.” Xinyan’s thesis is a computational and experimental study of the chemical, heat and mass transfer mechanisms governing the smouldering combustion of peat. His research focuses on peat, which is essentially a young coal, and is providing a fundamental understanding of the accidental burning of this sub-fossil fuel. These are the largest fires on Earth with a massive carbon footprint. He has written numerous significant peer-reviewed papers and presented his work at conferences and seminars in the UK, Europe and further afield. 

“Xinyan’s work has brought new insight and quantitative modelling to an important, but to date under-studied, source of carbon emissions, peat combustion,” says Professor Geoff Maitland, Founding Director of QCCSRC “He joins a list of previous winners who have gone on to successful careers in industry and academia and we will wish Xinyan well in his future endeavours.” 

As well as conducting his research, Xinyan is a Teaching Assistant at Imperial and has been a Visiting Scholar at University of Science and Technology in China and at the National University of Singapore. The Qatar Petroleum Medal and Prize was awarded to Xinyan at the dinner during the QCCSRC Annual Review. QCCSRC is based within the Department of Chemical Engineering and the Department of Earth Science and Engineering.

Tuesday, 3 February 2015

Wildfires and the burnig of Pine needles

In our recent paper published in Fire and Materials, we use laboratory experiments to investigate the differences in fire dynamics between live and dead pine needles. This is important because limited research has been conducted on the burning characteristics of live fuels, which are commonly assumed to behave like moist dead fuels.

The high flammability of conifer forests in the Mediterranean and Boreal biomes is due mostly to the presence of needles in very large amounts. Needles are fine fuels that ignite and spread flames faster than coarse woody fuels and represent an important portion of the total fuel consumption in wildfires. Needles are found both in the tree canopies and on the ground. Live needles (green colour) are part of the foliage and typically burn in crown fires. Dead pine needles (red colour) are on the ground, accumulating gradually on the litter and humus layers, and burn both in surface and ground fires.

Samples of Pinus halepensis needles used in the experiments (from left to right): live, aged and dead.

Our fire calorimetry results show good repeatability and demonstrate that the difference in burning dynamics of live and dead pine needles is significant and can be quantified and understood. Using a series of 10 flammability parameters extracted from the experiments, we show that the most flammable samples are fresh dead needles, followed by dry dead and dry live needles. The least flammable is fresh live needles. Live needles ignite about four times slower, and burn with ~60% lower power and ~50% lower heat of combustion than dead needles. The results confirm the importance of moisture content in the burning behaviour of pine needles, but the differences between live and dead samples cannot be explained solely in terms of moisture but require consideration of plant chemistry and sample drying.

(Left) Time to ignition and (Right) flaming time.

The results show that there are fundamental differences in the physics and chemistry of the flames of these fuels and that fire dynamics does not follow a simple trend from live to aged and to dead fuels.

Our results also defy the common assumption that oven drying only affects the water content of samples, or that the drying conditions are not important. Data suggest that observed fire behavior is substantially affected by the drying process in the oven, which induces chemical and structural changes (eg, loss of volatile organic compounds inside the oven). The fact that oven drying is widely used in wildfire laboratory studies merits more research.

- F Jervis, G Rein, Experimental study on the burning behavior of Pinus halepensis needles using small-scale fire calorimetry of live, aged and dead samples, Fire and Materials (in press) 2015.  (open access)