Issue link: https://fhpublishing.uberflip.com/i/736974
NETWORK / 9 / OCTOBER 2016 could provide a long-term sustainable solu- tion to decarbonisation of heat in the UK. "The challenge of the Climate Change Act is an 80% reduction in emissions from 1990 levels by 2050. Such a challenge requires big solutions. 'Bio' forms of gas can clearly contribute, but it is unlikely that…they can meet the 80% challenge and have the scale to fully decarbonise the UK gas grid." However, although hydrogen is an at- tractive zero-carbon fuel, making it in the quantities that would be required to support a gas grid conversion is signiŠ cantly more carbon intensive. The cheapest methodology for industrial- scale hydrogen production today, and the one proposed under the Leeds H21 scenario, is steam methane reformation (SMR). But in order to produce enough hydrogen to meet Leeds' current gas demand, an SMR plant would create approximately 1.5 million tonnes of CO2 per year – this is where CCS can shine. It's not just that CCS can extract carbon emissions from the SMR hydrogen produc- tion process in the same way it has been proposed it could suck CO2 from coal and gas-Š red power stations, it's that it could do so far more e˜ ciently and cheaply. Dr Keith MacLean at the Energy Research Partnership explains: "The hydrogen pro- duction process is much better suited to CCS than power stations because the process is characterised as continuous, with high concentrations of CO2 in an easily sepa- rable mix." Hydrogen production plants would also be "willing hosts" of CCS, says MacLean, unlike the average power station owner to whom the technology represents expense and a potential compromise for plant e˜ ciency. H21 proposes to apply 90% CCS to new SMR hydrogen production facilities on Teeside. The captured CO2 would then be compressed to 140 bar and sequestered deep under the North Sea. The approach has already been proven cost-e¡ ective and e˜ cient elsewhere. Air Products at Port Arthur, Texas, uses steam methane reformers to produce hydrogen from fossil fuels, feeding a 600km industrial corridor, and employs sequestered car- bon dioxide for enhanced oil recovery – a process that uses CO2 as a solvent to "clean out" existing oil Š eld with residual oil le£ in hard-to-reach pockets, thereby stalling in- vestment in expensive and environmentally damaging new Š elds. Globally, the H21 project report says that production of hydrogen by steam methane reformation runs to 50 million tonnes a year. This compares to just 0.15 million Dr Keith MacLean, industry chair, Energy Research Partnership, says it's time to think about the whole system costs and benefi ts of CCS. CLEARER THINKING FOR CCS: "Hydrogen production is an attractive application of CCS because at the moment the cheapest way of making hydrogen is by steam methane reformation. The big by-product of that is CO2 and that needs to be removed." "The hydrogen production process is much better suited to CCS than power stations because the process is characterised as continuous, with high concentrations of CO2 in an easily separable mix with a willing host." "One of the problems with CCS is that we've tried to incentivise it through the power station owners who are probably the ones who are least interested in making it work. Doing it through a fuel or gas producer would be more sensible because they have a positive benefi t in the future." "In order to make enhanced oil recovery work you need to have a large quantity of reliably sourced CO2. You can't do it with just a small amount every now and then. Using CCS with hydrogen production could potentially give a much more reliable source of CO2 for use in enhanced oil recovery." "Like it or not, nearly all of the international decarbonisation scenarios now rely on negative emissions because we have been so slow with mitigation and reduction. CCS, combined with things like biomass, is one of the few ways in which we can even consider producing negative emissions. "CCS value should be looked at in terms of cost per tonne of carbon saved, compared to alternatives. It should not just be about per megawatt hour costs on the power sector. This would create a basis for CCS cost comparison across sectors."