[{"command":"settings","settings":{"ajaxPageState":{"theme":"hm_theme","theme_token":"scxc61CzfZiD3nWrgErtXcrUoZcJbQH0fP8COp-t8PY","libraries":"eJwDAAAAAAE"},"ajaxTrustedUrl":{"form_action_p_pvdeGsVG5zNF_XLGPTvYSKCf43t8qZYSwcfZl2uzM":true},"pluralDelimiter":"\u0003","user":{"uid":0,"permissionsHash":"2af85631393b514cbde3779a1f71d92618d53b94b54ea1960d28b2e2d121ff12"}},"merge":true},{"command":"openDialog","selector":"#drupal-modal","settings":null,"data":"\u003Cdiv id=\u0022republish_modal_form\u0022\u003E\u003Cform class=\u0022modal-form-example-modal-form ecl-form\u0022 data-drupal-selector=\u0022modal-form-example-modal-form\u0022 action=\u0022\/en\/article\/modal\/6517\u0022 method=\u0022post\u0022 id=\u0022modal-form-example-modal-form\u0022 accept-charset=\u0022UTF-8\u0022\u003E\u003Cp\u003EHorizon articles can be republished for free under the Creative Commons Attribution 4.0 International (CC BY 4.0) licence.\u003C\/p\u003E\n \u003Cp\u003EYou must give appropriate credit. We ask you to do this by:\u003Cbr \/\u003E\n 1) Using the original journalist\u0027s byline\u003Cbr \/\u003E\n 2) Linking back to our original story\u003Cbr \/\u003E\n 3) Using the following text in the footer: This article was originally published in \u003Ca href=\u0027#\u0027\u003EHorizon, the EU Research and Innovation magazine\u003C\/a\u003E\u003C\/p\u003E\n \u003Cp\u003ESee our full republication guidelines \u003Ca href=\u0027\/horizon-magazine\/republish-our-stories\u0027\u003Ehere\u003C\/a\u003E\u003C\/p\u003E\n \u003Cp\u003EHTML for this article, including the attribution and page view counter, is below:\u003C\/p\u003E\u003Cdiv class=\u0022js-form-item form-item js-form-type-textarea form-item-body-content js-form-item-body-content ecl-form-group ecl-form-group--text-area form-no-label ecl-u-mv-m\u0022\u003E\n \n\u003Cdiv\u003E\n \u003Ctextarea data-drupal-selector=\u0022edit-body-content\u0022 aria-describedby=\u0022edit-body-content--description\u0022 id=\u0022edit-body-content\u0022 name=\u0022body_content\u0022 rows=\u00225\u0022 cols=\u002260\u0022 class=\u0022form-textarea ecl-text-area\u0022\u003E\u003Ch2\u003ESea floor experiment to test carbon storage plans \u003C\/h2\u003E\u003Cp\u003EOut in the choppy waters of the North Sea, 100 km from the Scottish coast, they will inject a tonne of CO2 into the sediment. Patrolling the ocean floor will be a suite of state-of-the-art sensors, watching, listening and identifying the gas. The question they want to answer is this: if CO2 ever escaped from undersea storage, would we be able to detect it?\u003C\/p\u003E\u003Cp\u003EAccording to the International Energy Agency, around \u003Ca href=\u0022http:\/\/ieaghg.org\/ccs-resources\/what-is-ccs\u0022 target=\u0022_blank\u0022 rel=\u0022noopener noreferrer\u0022\u003Ea third\u003C\/a\u003E of all CO2 emissions come from fossil fuels used for generating electricity. It believes these emissions could be substantially reduced using carbon capture and storage (CCS) \u2013 where CO2 is pumped into deep aquifers or empty oil and gas reservoirs.\u003C\/p\u003E\u003Cp\u003EHowever, such a drastic solution to climate change alarms some, partly due to fears we might be leaving our descendants a dangerous legacy.\u003C\/p\u003E\u003Cp\u003E\u2018The risky bit is the first few hundred years,\u2019 said Professor Klaus Wallmann of the GEOMAR Helmholtz Centre for Ocean Research Kiel in Germany and coordinator of the ECO2 project which looked at the risk of leaks from underground storage reservoirs.\u003C\/p\u003E\u003Cp\u003EThe CO2 will be safe in the very long term because, as the millennia unfold, it will dissolve, creating a liquid too high in density to migrate upwards.\u003C\/p\u003E\u003Cp\u003EBut in the shorter term there is a risk that the CO2 will escape\u0026nbsp;through some undetected geological structure \u2013 such as a chimney or pipe structure.\u003Cdiv class=\u0022tw-text-center tw-bg-bluelightest tw-p-12 tw-my-12 tw--mx-16\u0022\u003E\n \u003Ch3 class=\u0022tw-font-sans tw-font-bold tw-text-blue tw-uppercase tw-text-lg tw-mb-8\u0022\u003EThe Issue\u003C\/h3\u003E\n \u003Cspan class=\u0022tw-inline-block tw-w-1\/6 tw-h-1 tw-bg-blue tw-mb-8\u0022\u003E\u003C\/span\u003E\n \u003Cp\u003ECarbon capture and storage (CCS), where carbon dioxide is captured before it hits the atmosphere and stored underground, is a \u003Ca href=\u0022http:\/\/ec.europa.eu\/clima\/policies\/lowcarbon\/ccs_en\u0022 target=\u0022_blank\u0022\u003Ekey tool\u003C\/a\u003E in meeting the EU\u2019s targets to reduce carbon emissions by \u003Ca href=\u0022http:\/\/ec.europa.eu\/clima\/policies\/strategies\/2030_en\u0022 target=\u0022_blank\u0022\u003E40\u0026nbsp;% from 1990 levels\u003C\/a\u003E by 2030.\u003C\/p\u003E\u003Cp\u003EIt is thought that it could be \u003Ca href=\u0022http:\/\/ec.europa.eu\/clima\/policies\/lowcarbon\/ccs_en\u0022 target=\u0022_blank\u0022\u003Eparticularly effective\u003C\/a\u003E in countries which rely heavily on fossil fuels and have a fast-growing demand for energy.\u003C\/p\u003E\u003Cp\u003EThe EU has set out a \u003Ca href=\u0022https:\/\/ec.europa.eu\/clima\/policies\/lowcarbon\/ccs\/directive_en\u0022 target=\u0022_blank\u0022\u003Elegal framework\u003C\/a\u003E for the safe geological storage of CO2 and researchers are continuing to investigate the effectiveness and practicalities of the technology in a number of EU-funded projects.\u003C\/p\u003E\n\u003C\/div\u003E\n\u003C\/p\u003E\u003Cp\u003ETo explore this, the project studied seepage of methane, which behaves like CO2, from natural repositories and drilled wells.\u003C\/p\u003E\u003Cp\u003EWhat they found was that because of the distances, pressures and temperatures involved, the rate at which the methane emerges turns out to be between one and ten tonnes a year.\u003C\/p\u003E\u003Cp\u003EA typical\u0026nbsp;CCS facility might sequester a million tonnes of CO2 a year.\u003C\/p\u003E\u003Cp\u003EAt another EU-funded project, PANACEA, researchers modelled the flow of CO2 in natural and artificial repositories.\u003C\/p\u003E\u003Cp\u003E\u2018What we have learned is that, if there is leakage from the reservoir, it will not be substantial in most cases,\u2019 said coordinator Dr Jacob Bensabat of Environmental and Water Resources Engineering, in Haifa, Israel.\u003C\/p\u003E\u003Cp\u003E\u2018Model investigations have indicated that, when it occurs, CO2 leakage is relatively limited in quantities. As it migrates upwards from the reservoir the CO2 becomes gaseous and thus is more mobile but the quantities are small.\u2019\u003C\/p\u003E\u003Cp\u003EThe sea urchin crawling along the sea floor, however, might not be so sanguine about belches of carbon dioxide acidifying its environment, threatening to dissolve its calcareous plates and releasing toxins from nearby rocks. Many can adapt briefly to increased acidity but a long-term change would be a different matter.\u003C\/p\u003E\u003Cp\u003EIn the North Sea, however, ECO2 has shown that sea creatures are well protected \u2013 from both acidity and also from excessively salty water the CO2 might push before it \u2013 by ocean currents that rinse the environment at millions of tonnes a second.\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EDetecting releases\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003ENevertheless, detecting releases is crucial. New European legislation dictates that storage sites be monitored for at least 20 years after injection ceases. Aside from safety, there is the issue of carbon trading: a company must be able to quantify how much carbon it has sequestered and how much has leaked away.\u003C\/p\u003E\u003Cp\u003EProfessor Douglas Connelly, of the National Oceanography Centre in Southampton, UK, runs the STEMM-CCS project, which is conducting the North Sea experiment. The project, which is coordinated by the UK\u0027s Natural Environment Research Council, is deploying\u0026nbsp;hydroacoustic sensors that can \u2018hear\u2019 bubbles of gas trickling from the deep \u2013 and can even distinguish between them and those lurking in a fish bladder. Chemical sensors can tell whether a surge of carbon dioxide has come from a biological or inorganic source.\u003C\/p\u003E\u003Cp\u003EBut Prof. Connelly says there are gaps. \u2018Unless there\u2019s a very large blowout it could be very difficult to detect a release.\u2019\u003C\/p\u003E\u003Cp\u003EOne reason is that CO2 emerges from the sediment as a gas but swiftly dissolves in the sea water: the hunt is for tell-tale droplets of liquid in the \u2018inherent vastness of the ocean\u2019, as Connelly\u2019s research team puts it.\u003C\/p\u003E\u003Cp\u003EAnother problem is financial: today\u2019s sensors must often be deployed or managed from ships that cost around EUR 30 000 a day to operate.\u003C\/p\u003E\u003Cp\u003ESTEMM-CCS\u2019s experiment on the floor of the North Sea will be a first, testing a raft of new sensors honed to spot the dissolved CO2, to work autonomously, and to tough it out in the turbulent realities of the ocean.\u003C\/p\u003E\u003Cp\u003EThe team has developed a so-called optode, which picks up acidity changes by optically measuring the responses of a dye. A lab-on-a-chip will detect a range of chemicals. \u0026nbsp;\u003C\/p\u003E\u003Cp\u003EAdd to this a new control system and devices to check on background factors such as temperature and pressure, and the result is a platform that might look well in a playground. Bright orange circular bars enclose a cluster of yellow, spherical pods, each of which can be released on demand to float the latest data up to the surface, whence it is beamed home.\u003C\/p\u003E\u003Cp\u003EAfter years of preparation, a research ship will depart in 2019 for a mooring above a depleted gas field in the North Sea to simulate emission from a storage site.\u003C\/p\u003E\u003Cp\u003EIt will release a seabed lander packed with cylinders of carbon dioxide gas which will drift down 120 metres to the floor. The CO2 will then be pumped along a drilled well and emerge several metres below. Sensors, packed into small landers and bullet-like autonomous submarines, will click into action.\u003C\/p\u003E\u003Cp\u003EThe trip is unique, says Prof. Connelly, because it takes place in real sediments in the North Sea, subject to the whims of the ocean, and above a genuine potential CCS site.\u003C\/p\u003E\u003Cp\u003E\u2018We\u2019re going to try to find out what would happen in the real world,\u2019 he said.\u003C\/p\u003E\u003Cp\u003E\u003Cem\u003EIf you liked this article, please consider sharing it on social media.\u003C\/em\u003E\u003C\/p\u003E\u003C\/textarea\u003E\n\u003C\/div\u003E\n\n \u003Cdiv id=\u0022edit-body-content--description\u0022 class=\u0022ecl-help-block description\u0022\u003E\n Please copy the above code and embed it onto your website to republish.\n \u003C\/div\u003E\n \u003C\/div\u003E\n\u003Cinput autocomplete=\u0022off\u0022 data-drupal-selector=\u0022form-z3jexp7mlg7-ubxadl9pf9rfv88ss8-k742u-rj7ica\u0022 type=\u0022hidden\u0022 name=\u0022form_build_id\u0022 value=\u0022form-z3JeXp7mLg7_uBxAdl9PF9rfv88sS8-K742u-RJ7IcA\u0022 \/\u003E\n\u003Cinput data-drupal-selector=\u0022edit-modal-form-example-modal-form\u0022 type=\u0022hidden\u0022 name=\u0022form_id\u0022 value=\u0022modal_form_example_modal_form\u0022 \/\u003E\n\u003C\/form\u003E\n\u003C\/div\u003E","dialogOptions":{"width":"800","modal":true,"title":"Republish this content"}}]