Last week the Coal Research Forum held their 11th European Conference on Coal Research and its Applications (ECCRIA) at the University of Sheffield. I attended with IEA CCC colleagues Ian Reid and Maggie Wiatros-Motyka, who has also been involved in the organisation of the event. Sheffield was a fitting venue, as it provided an opportunity to visit the nearby ‘PACT’ research facility, shared by several universities under the banner of the UK CCS Research Centre. Housing several combustion and CO2 capture pilots, this site was recently chosen to be the new host for the International Flame Research Foundation (IFRF), a venerable and respected combustion research institute which has moved here from Livorno in Italy.
On the opening day, delegates were roused by an impassioned talk from the European coal lobby Euracoal, evidently frustrated from fighting a losing battle against other energy sources with the Commission. Some interesting points were made highlighting the rather disproportionate support natural gas power has seen in recent years, given that modern coal plants can match gas for flexibility and (non-CO2) emissions, and the fact that coal is a European resource whilst natural gas is almost entirely imported. An opening session on the work of the newly arrived IFRF brought the conference back to more a more familiar research theme, with details of the important work the Foundation have done in spectrometric studies of coal flames and building up an extensive database fo solid fuels and their combustion behaviour.
The conference also provided a venue for the final knowledge sharing event of the EU-funded oxyfuel research project known as Relcom, which has sought to develop computational models and equipment to ensure reliable coal combustion in oxyfuel-based carbon capture, and many of the talks came from the diverse partners in this consortium. Much of the Relcom work was conducted on a 20 MWt pulverised coal pilot at the Ciuden research centre in Spain, where they ended up replacing the four existing burners with four new burners tailored to oxyfuel operation. Instead of mixing oxygen into recycled flue gases upstream, these injected pure oxygen directly into the burner, to give greater load flexibility and allow less flue gas recycle. Computational work by Doosan Babcock and others looked at how existing fluid dynamics models needs to be adapted to account for the completely altered gas composition of the boiler atmosphere in oxyfuel combustion.
Biomass combustion features increasingly in the agenda of many coal conferences, in the UK in particular, as many coal research groups appear to be turning towards this key renewable energy source which exploits the same infrastructure and research techniques as the fading coal industry. There are important differences between coal and biomass combustion which require extensive investigation, and much like oxyfuel combustion, computational models and hardware such as mills and burners must be tailored to the new conditions. One of the main issues with biomass is its lack of uniformity, with a much greater range of size and shape particles compared to coal, and correspondingly unpredictable combustion behaviour. Variations on existing combustion models for coal have been tested at several UK universities, and extensive biomass tests have been conducted at PACT’s 250 kW pilot. A lesser-known bubbling fluidised bed pilot housed at the same site has also been used to study the important issue of agglomeration of different biomass fuels in this kind of boiler.
I led off a couple of sessions on carbon capture with my own review of novel capture technologies, but it is noticeable that the prominence of UK research in this field has dropped off from a few years ago. Nevertheless, a talk on the post-combustion capture pilot at PACT described how the unit is providing valuable information on the performance of various commercial and experimental CO2 solvents, having recently had various upgrades such as structured packing in the absorber column. Other research groups have looked at solid sorbent materials as a low-energy alternative to these liquid solvents, but such advanced materials often suffer from complex and costly syntheses. Important work at the University of Nottingham has therefore developed a continuous, scalable synthesis for metal organic frameworks – huge surface area materials which have shown high CO2 capture performance but are so far difficult to manufacture in significant quantities. The Japanese research institute RITE described their work on silica-supported amines, which has achieved impressive thermal energy penalties of 1.5 GJ/t CO2 (compared to over 2 usually seen for liquid amines), and scale up of the capture process is planned with Kawasaki Heavy Industries.
Parallel sessions that I was unable to attend looked at emissions control, combustion studies, gasification, and ash and coal characterisation. This conference brings together a familiar core of researchers from the well-established coal and combustion research centres around the UK (both academic and industrial), as well as many researchers from further afield. We finished with a quick tour of the PACT facility, where we were shown two commercial gas turbine units, a 250 kW downshot pulverised combustion pilot used for coal, biomass, and oxyfuel research, and the post-combustion absorber rig used for solvent research. For details of this important UK research facility, you can see a blog I wrote following my first visit in 2014.