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Biomass fuelled power generation with CO2 capture, 24 May, Cambridge UK

This interesting one-day event was organised by the Combustion Institute, the Institute of Physics, cmcl innovations and Cambridge University. It was held in the Moller Centre, Cambridge and opened by Prof Markus Kraft (Cambridge University). The morning was dedicated to more practical work on Bio-CCS, and in the afternoon the focus was on university research on the various aspects of biomass combustion and CCS.
Greg Kelsall outlined the results of the EBTP/ZEP report on Bio-CCS: the way forward for Europe – a piece of work that I contributed to. It’s available from http://www.biofuelstp.eu/bio-ccs.html. A potential advantage of Bio-CCS is that it could lead to negative emissions, if the biomass is sustainably produced in a carbon-neutral manner, and the CO2 released from combustion of this material is captured and stored. One of the factors limiting development of bio-CCS is that negative emissions as yet have no value in the EU ETS.
Dr Amit Bhave (cmcl innovations) has studied the techno-economics of bio-CCS, and concluded that it could be very important. There is one bio-CCS plant operational in Illinois, USA. Dr Bhave calculated that compared to a fossil-fuelled plant, bio-CCS would have a 5-15% efficiency drop 45-130% increase in CAPEX and 4-36% increase in OPEX.
Dr Jeremy Tomkinson (NNFCC) outlined the UK bioenergy market and bioenergy policies. For biomass, wood and energy crops are the favoured options. Sustainable biomass could contribute 8-11% of UK energy demand by 2020. He estimates that 50 mt biomass is available from waste in the UK, and that the demand for biomass could be about 23 mt by 2020. However, the increasing demand means that serious investment in infrastructure is required.
Dr Nigel Burdett (Drax) gave a very interesting presentation. So many talks are given about various theories to maximise biomass use, how to obtain it, process it and use it, that it is very refreshing to actually hear what is really going on and the decisions Drax have made, backed up by a £700 million investment programme. Drax is a 4000 MW plant, currently burning 10 mt/y coal. It is the largest emitter of CO2 in the UK (at about 22mtCO2/y). Drax has experience of cofiring but is now fully converting 3 of its 6 units to run on biomass. The first unit was converted in April 2013. The biomass is moved in covered railway wagons and stored in domes. Each domes can store 80,000 t biomass. The fuel of choice at Drax is wood pellets, which must be clean to minimise corrosion. NO reductions are down compared to coal combustion, so SCR is not necessary; SO2 emissions are low so the FGD has been taken out of service. Ash production is lower, and Drax are investigating the potential of selling the ash as fertiliser.
By 2016, when the 3 units are converted, Drax will need 8 mt/y of pellets. They are primarily being sourced from the USA and Canada. In fact, Drax is constructing its own pellet plant in North America to guarantee security of supply. As Dr Burdett said ‘ biomass availability is key, and biomass sustainability is the challenge’. Drax has its own sustainability criteria that suppliers must adhere to, but they would like national and international sustainability critieria to be introduced by governments to ensure a uniform standard.
There are 2 phases to the development at Drax. From 2013-2020 they will develop their use of sustainable biomass to facilitate a low cost transition to a low carbon economy. Post-2020, they envisage a future using bio-CCS.
Prof Jenny Jones (University of Leeds) gave an interesting update on torrefaction developments. Dr Ausilio Bauen (E4tech) gave an overview of biomass supply chain issues from a UK perspective. Dr Paul Fennell (Imperial College) discussed the potential of chemical looping for carbon capture, and Michael Priestnall (Cambridge Carbon Capture) described their work to use mineral carbonation as a stand-alone option for bio-CCS.
More information about the event is available at http://www.cmclinnovations.com/?page_id=3013

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