(The author is a Reuters market analyst. The views expressed
are his own.)
By Gerard Wynn
LONDON, July 3 (Reuters) – Technology that would convert
carbon dioxide from a scourge on the climate to beneficial
products is inching towards commercial reality and is already
cheaper than carbon capture and storage.
CO2 can, in theory, be converted in the making of such
products as concrete, plastics and minerals. (See Chart 1) There
are major problems, however. Annual CO2 emissions far exceed the
global market for such products, and some of these products
release CO2 back into the atmosphere.
But some products such as concrete are long-lived, and costs
are falling.
The technology deserves a bigger share of R&D; funding
compared with carbon capture and storage (CCS), the other big
potential solution being considered which after a decade has
still not achieved a single full-scale demonstration.
Under CCS, CO2 is stripped from flue gases and buried in
underground reservoirs such as spent oil and gas fields or
saline aquifers.
Enhanced oil recovery (EOR) has aspects in common with both.
The CO2 is stored underground as in CCS, but like carbon
conversion the gas goes to profitable use by increasing
production from ageing oil wells.
All are untested at full scale because of the high costs of
capturing CO2 in the first place. Carbon conversion and CCS
share the same initial step of separating CO2 from a diluted
stream of exhaust gases.
***************************************
Chart 1: http://link.reuters.com/dud49t
Chart 2: http://link.reuters.com/fud49t
***************************************
FUNDS
CCS is being tested as a solution for emissions from fossil
fuel-fired power plants, while carbon utilisation technology, at
least at the demonstration stage, has focused on industrial
processes.
CCS has a longer history and has received much more funding,
reflecting concerns about power plant emissions. Underground
reservoirs could, in theory, store more than a century’s worth
of global carbon emissions.
In the United States, the 2009 American Recovery and
Reinvestment Act raised $3.4 billion for all forms of carbon
capture, according to a Congressional Research Service report
published last month (“Carbon Capture and Sequestration:
Research, Development, and Demonstration at the U.S. Department
of Energy”).
The funding led to 10 programmes, only one of which
(“Industrial Carbon Capture and Storage”) specifically supported
CO2 utilisation, with around $160 million.
Carbon utilisation secured just 5 percent of the funding in
2010, with most of the rest going into geological storage,
according to a report by the U.S. National Energy Technology
Laboratory (NETL). (“Carbon Sequestration Program: Technology
Program Plan”, 2011) (Chart 2)
COST
Even so, carbon conversion is already far ahead on
competitiveness.
McKinsey has estimated the full cost of stripping CO2 from
power plant flue gases and sequestering it underground at about
40 euros ($52.14) per tonne of CO2 in 2030. (“Impact of the
financial crisis on carbon economics”, 2010)
The recovery act set a target of 2015 to “develop
technologies for fixing CO2 in stable products with indirect
sequestration at costs of no more than $10 per metric ton of CO2
used”.
Comparing these costs per tonne may be a little unfair. The
flue gas of a cement plant contains a more concentrated stream
of CO2 at about 15 to 30 percent than do power plants at 5 to 10
percent, making separation cheaper.
Nevertheless, the cost difference illustrates the advantage
of finding an economic use for CO2.
Manufacturers of precast concrete products can “cure” a wet
cement mixture with CO2 instead of steam. The cement combines
chemically with CO2 to produce a stronger concrete than it would
with water.
Such CO2 abatement could be sited next to cement
manufacture, the second-biggest stationary source of CO2
emissions after power generation.
NETL says the process has so far achieved 90 percent
recovery from injected CO2 and that it “should result in a net
process cost of less than $10 per ton of CO2 stored”.
(“Beneficial Use of CO2 in Precast Concrete Products”, May 2013)
CO2 could also potentially be used to make organic
carbonates, which go into manufacturing plastics. The main task
in this case is to find a catalyst that allows CO2 to react with
organic compounds at ambient temperatures.
NETL reports that a U.S. Department of Energy project has
made progress in identifying suitable catalysts. (“Integrated
Electrochemical Processes for CO2 Capture and Conversion into
Commodity Chemicals”, May 2013)
SKYONIC
A third potential use is conversion into carbonate minerals,
which have various uses including as construction materials.
Texas-based Skyonic has patented a process to combine waste
CO2 with salt and water to make products including baking soda
(sodium bicarbonate) and hydrochloric acid, which can be used as
a shale gas fracking fluid.
The company is one of six to progress under the “Industrial
Carbon Capture and Storage Projects” programme of the Recovery
Act.
Last week, Skyonic announced that it had raised the debt and
equity financing it needed to build a plant alongside a cement
plant, which it expects will make baking soda and other products
profitably within three years.
It is unclear how permanent the CO2 removal may be. For
example, the company lists glass manufacture as one ultimate
market, but glass-making vents CO2 from heating sodium
carbonate.
Also the company is frank about the scale limitations of
conversion of CO2. The global market for sodium carbonate and
bicarbonate is equal to around 0.2 percent of global annual CO2
emissions, it calculates.
The market is more impressive for cement and concrete, which
Skyonic says could account for up to around 11 percent of
global CO2 emissions.
At the least, carbon conversion can take a bite out of
annual emissions and is important in the near term given the
slow progress in commercialising CCS.
($1 = 0.7672 euros)
(editing by Jane Baird)
