The world’s largest carbon capture project went online last week, but unlike the first commercial-scale carbon capture and storage project at Boundary Dam in Saskatchewan, this endeavour is selling the captured carbon dioxide for a profit, rather than storing it underground.
Petra Nova, a joint US-Japanese commercial operation, cost US$1 billion to construct, including a $190 million grant from the US Department of Energy, and aims to capture some 1.4 million tonnes of CO2 annually from an ordinary coal-fired power plant near Houston. The CO2 is then sent via pipeline and injected into a depleted oilfield and squeeze out more oil than would otherwise be possible. The process, known as enhanced oil recovery, allows the carbon capture to operate on a commercial basis without subsidy beyond the start-up grant.
Until now, no carbon capture operation has recovered its costs, but Petra Nova says it is able to recoup its expenses at the current price of a barrel of oil of US $50-55.
Climate watchers will be quick to point out that enhanced oil recovery still produces greenhouse gas (GHG) emissions, both in the production process and most importantly when the oil is combusted, even if the net emissions are lower.
But the capture of GHGs coupled with utilization, instead of storage, does not have to result in further emissions. One project along these lines, backed in part by PICS, is investigating how methane emissions from agriculture can be captured and used elsewhere within the agriculture sector.
In British Columbia, livestock produce 2.7 million tonnes of manure annually. People living nearby have to suffer through these waste odours, soil and waterways can be contaminated and of course manure is itself a major source of agricultural GHG emissions. Methane and nitrous oxide are emitted when microbes decompose organic matter during storage of manure and when spread on the field as fertilizer.
But if manure can instead be converted to renewable ‘biogas’, it can replace the use of natural gas for heating greenhouses. This happens via anaerobic digestion in steel tanks, a biological process whereby microbes break down organic material in the absence of oxygen. A byproduct of the digestion process can be CO2, but if this is pumped into greenhouses, plants will take in the gas as they grow. The residue leftover meanwhile can be used as a bio-fertilizer (a non-synthetic fertilizer). The researchers then incorporated mushroom houses into the system as well, with the mushrooms operating as recipients of the bio-fertilizer and as producers of CO2 for plant growth.
They have found that such an integrated manure-biogas-fertilizer system is able to decrease non-renewable energy consumption (by displacing use of natural gas for heating) and therefore reduce GHG emissions by 40 percent compared to conventional farming operations. In addition, such a system reduces odours and human health impacts.
Taking their investigations to the next level, researchers plan to incorporate other agricultural activities and food waste into this dairy farm-greenhouse-mushroom integrated system to further improve by-product use and renewable energy production, and to explore its implications for the Lower Mainland and Fraser Valley.
Hydroelectricity has long been assumed to be a cornerstone of any future low-carbon economy, but disappearing glaciers are altering the equation