Carbon Engineering's air contactor absorbs atmospheric CO2 into the capture solution to produce a liquid rich in CO2. The regeneration process, involving several processing steps, produces a purified stream of CO2 and recreates the original capture chemical for re-use in the contactor. These two processes work together to enable continuous capture of CO2 from the atmosphere, with energy (and small amounts of make-up chemicals) as an input, and pure CO2 as an output. The extracted CO2 is combined with all the CO2 from the systems energy use and both are delivered as a high-pressure pipeline-quality product stream which can be sold for use in industrial applications and/or permanently sequestered (geologically stored) deep underground.
Inputs: Air, water, natural gas. Electricity produced on site.
Outputs: High pressure CO2.
1 tonne-CO2 from air + 0.5 tonne-CO2 from natural gas = 1.5tonne-CO2 delivered
Nth plant costs: • $100-$120/tonne-CO2 - captured $70-$80/tonne-CO2 - delivered
Carbon Engineering's air contactor design captures CO2 with a strongly alkaline hydroxide solution. This solution has been optimised to quickly absorb CO2 by careful selection of concentrations and additives.
Carbon Engineering has developed, patented, and prototyped a unique contactor design that maximizes CO2 absorption by utilizing a large solution surface area, optimized air turbulence and mixing, and solution-refresh rates, enabling cost-effective capture of industrial-scale quantities of CO2 with low solution pumping and fan energy inputs, and minimal land use requirements. Both the potassium hydroxide [KOH] reactant used in the air contactor and the produced potassium carbonate [K2CO3] are non-toxic.
In Carbon Engineering's regeneration cycle, the CO2-rich chemical solution from the air contactor is processed to release pure, compressed CO2, and also to re-generate the original capture solution for further use.
This cycle is an innovation based on a 100 year old industrial process using well understood and existing technology:
After CO2 is captured in the air contactor, it forms potassium carbonate [K2CO3], which is carried to the regeneration cycle dissolved in solution. This solution is fed into a pellet reactor which simultaneously reacts it with calcium hydroxide [Ca(OH)2] to regenerate the potassium hydroxide [KOH] for reuse in the air contactor, and precipitates the CO2 out of solution as solid calcium carbonate [CaCO3].
Once the solid calcium carbonate [CaCO3] has been separated from the solution, it is sent to a fluid-bed calciner. The calciner operates at about 900°C which causes the calcium carbonate [CaCO3] to decompose into calcium oxide (CaO), during which pure CO2 is released as a gas. The calciner burns fuel, such as natural gas, in an oxygen environment to supply the heat needed to perform this reaction. The calciner also generates heat that is used to supply electricity for the rest of the air capture plant. The CO2 produced by burning the fuel mixes with the captured atmospheric CO2 and all the CO2 is sent to a final compression and clean-up stage to produce pure, pipeline-quality CO2.
After the solids have released their CO2, they are then sent to a mixing tank where they react with water to re-form fresh calcium hydroxide [Ca(OH)2]. This calcium hydroxide is recycled to the pellet reactor for reuse.
Carbon Engineering's business strategy is to integrate atmospheric CO2 into liquid fuel production in order to leverage near-term premium-value markets for low carbon-intensity fuels.
SOURCE: Figures 1-4 www.carbonengineering.com
DAC does not compete with CCS in reducing emissions from large fixed sources such as electric power or by being cheaper on a $/tonne basis, but by providing an atmospheric – rather than geological – CO2 source, which when used to produce fuels, can result in a lower life-cycle carbon intensity (CI) than fuels produced from CCS CO2. Low CI fuels command a premium value in carbon-constrained transportation markets, such as California’s Low Carbon Fuel Standard. The business model for commercializing DAC is different than that for CCS, and there are sizeable existing markets where it is already competitive.
The origin of CO2 that is used to produce fuels – whether embodied in petroleum, mined for enhanced oil recovery (EOR), or captured from the air -- is crucial to determining the net flow of CO2 from the sub-surface to the atmosphere, and thus in determining the life-cycle carbon intensity of the fuel. For example, an algal pond supplied with CO2 from a geologic reservoir—often the lowest cost CO2—results in algal biofuel with a CI very similar to that of conventional oil because the net transfer of carbon from geologic reservoirs to the atmosphere would be the same. The following scenarios illustrate the role of the CO2 source in determining the carbon intensity of fuels produced from EOR.
Scenario A: Conventional EOR Fuel Production:
A geologic CO2 reservoir supplies CO2 for EOR to produce petroleum, and ultimately fuel. The carbon intensity (CI) can vary depending upon the specifics of the EOR field and the petroleum in the reservoir, but a typical value is 95 g-CO2/MJ as represented by the bar to the right of the image below.
Scenario B: Power Plant CCS to EOR:
In this scenario the source of CO2 is still geological. Coal or gas—which embody geologic carbon—are extracted and used in a power plant with CCS and the resulting CO2 is used to produce fuel using EOR. A simple interpretation is that the fuel has the same 95 g-CO2/MJ CI as in the first scenario, although the system has produced low-carbon electricity. Under some regulatory regimes any emissions reductions in the electricity sector can be partially allocated to the fuel, but clearly it is not possible to claim both low carbon fuel and low carbon electricity.
Assuming the low-carbon electricity displaces US grid average carbon intensity, and all electric-sector emissions reductions are allocated to the fuel, the resulting fuel CI may be in the order of 40 g-CO2/MJ (right hand bar of the figure). Note that as natural gas and renewables gain in the generation portfolio the grid average intensity decreases, so do the reductions obtained by replacing grid electricity with CCS electricity, so that in a fully de-carbonized grid CCS-EOR produces fuel with exactly the same CI as conventional oil.
Scenario C: Air Capture to EOR:
DAC captures CO2 from the air, which compensates for the CO2 released in fuel use, and in effect recycles the emissions for re-use in fuel production. Fossil fuel is used to power DAC and both the combustion CO2 and atmospheric CO2 are captured and injected for EOR. The CO2 delivered to the oil reservoir is permanently sequestered, resulting in a low CI fuel, roughly 35g-CO2/MJ or lower (depending on the oil to CO2 'lift ratio').
DAC enables the direct extraction of CO2 from the atmosphere, which cannot be accomplished by CCS. This enables revenue streams and associated business models that are distinct from those available to CCS. These revenue streams can be much larger per tonne of CO2 from the atmosphere than the revenue streams available per tonne of CO2 avoided in the power sector.
DAC is harder and more expensive than capture from power plants. Likewise cutting carbon in the transportation sector is harder and more expensive than decarbonising the electricity sector. DAC should be viewed as competing with biofuels and electric vehicles, not with power-plant CCS and wind power. Finally, regulators have often imposed higher effective carbon prices on the transportation sector than on electricity. DAC is more expensive than CCS but it competes in a different market with a different incentive structure than CCS.
The per barrel cost of DAC-EOR fuel is about 20% higher than the cost of conventional oil and it has a carbon intensity that is lower than most biofuels. DAC thus provides a near-term scalable technology that can supply low-carbon transportation fuels at a lower cost (and a lower land use footprint) than most biofuels. This gives DAC near-term markets where it can compete despite having a higher cost per ton than power-plant CCS.
Algal biofuels require CO2 enriched air. This can be supplied from a power plant only if the two plants are collocated, a requirement that severely restricts the scope for algal biofuels which also require water, cheap land and high insolation. Moreover a power-plant/algal-biofuel system can claim low carbon electricity or low carbon fuels but not both.
Founded in 2009 by David Keith, a global authority on DAC, Professor of Applied Physics and Professor of Public Policy at Harvard, Carbon Engineering has raised about CAN$19m in equity and CAN$7.5m in grants (with a further CAN$7.0m due over the next couple of years) for development of its technology to the point where final-stage pre-commercialisation plant in Squamish B.C has been capturing a tonne of CO2 a day since Summer 2015. By Summer 2017, this will be coupled to an Air-to-Fuels (A2F) plant in an integrated end-to-end process of DAC/A2F producing 1bbl/day of ultra-low-carbon fuel. A First-Of-A-Kind (FOAK) commercial plant is then planned for 2018 to be followed thereafter by 1m tonne plants in full-scale commercial roll-out. It's founder-shareholders, who have supported the enterprise through four financing rounds, are Bill Gates and Murray Edwards, chairman of Canadian Natural Resources.
DAC offers two main routes to de-carbonization: (i) the production of low, or zero-carbon fuels, and (ii) sequestration and offset. It has significant advantages over CCS in that it can address the 60% of emissions which are non point-source (or distributed); the captured CO2 is carbon-negative, enabling the production of drop-in compatible, zero-carbon fuels; and it is locationally flexible, reducing pipeline requirements and allowing on-site CO2 feed-in.
Global transportation rests upon circa $50 trillion of built infrastructure to produce, distribute, and burn high energy-density liquid hydrocarbons. Over $3trn of these fuels are consumed each year, but environmental and climate impacts pose growing concerns in relation to their use. Technologies such as battery vehicles and biofuels attempt to address these impacts but, in many cases, will be limited to niche applications due to low energy density or high land-use (the energy density of batteries is 1/30th that of hydrocarbon fuels, and meeting global fuel demands through biofuel would require a land area equal to that occupied by global agriculture. Hydrogen is difficult to transport and requires an entirely new infrastructure. This leaves a compelling near-term opportunity for DAC, which can deliver atmospheric CO2 to produce industrial quantities of drop-in low-and zero-carbon hydrocarbon fuels, fully compatible with today's infrastructure.
Carbon Engineering's DAC technology scrubs CO2 directly from the atmosphere using scalable technology that binds together a set of proven industrial processes in a novel configuration using unique IP. The process is 'closed loop' in that it does not require significant chemical inputs (figure 1). In a first step, the air contactor derived from cooling tower technology inexpensively ingests air and absorbs the CO2 into a liquid solution (figure 2). The second step – derived from a pulp and paper industry process separates the CO2 as a pure stream at high pressure and industrial pipeline grade, while also regenerating the original capture solution. Energy for the current generation system is provided by natural gas with no significant requirement for grid power, and the half tonne of CO2 from gas combustion is also captured, so that 1.5 tonnes of pipeline quality CO2 are delivered for every 1 tonne of CO2 captured from the air (figure 3). Future systems will utilize solar energy as mass deployment enables projected cost reductions. In contrast to its competitors, who have focused on novel adsorption materials with long commercialization times and high risk, Carbon Engineering's system is, wherever possible, based on scaleable industrial equipment and processes, thus taking advantage of precedent and long standing expertise to accelerate deployment and mitigate technical risk.
Carbon Engineering's technology and business is patent-protected, with eight core patent families and a further 20 applications pending.
There are five major markets for Carbon Engineering: Air to Fuel synthesis; Enhanced Oil Recovery/Low Carbon Fuel Standards; Algal Biofuels; and sequestration for offsets ('virtual' zero-carbon fuels, voluntary and CDM markets) and atmospheric reduction.
AIR-TO-FUEL SYNTHESIS (A2F):
Synthetic hydrocarbon fuels produced from atmospheric CO2 substituting for the $3trn/year fossil fuel sources represents the largest immediate potential market for DAC. Transportation fuels cost much more per unit of energy than centralised facilities. At $100/bbl, the cost of oil is around $20/GJ and gasoline much higher still. This compares with wind power at $14/GJ for the best sites, and solar thermal at around $5/GJ ($8.9/GJ for solar electricity generation).
Using well established chemical engineering (such as Fischer-Tropsch followed by ExxonMobil's Methanol to Gasoline process), it is possible to make 1,000 litres of gasoline from roughly 40GJ of hydrogen and 2 tonnes CO2. Recent cost-reductions in solar pv generation (falling by a factor of three over the last five years, with further cost-reductions projected by 2020), and the development of low capital cost electrolysis technologies, has rapidly reduced the cost of industrial-scale carbon-neutral hydrogen. This, coupled to Carbon Engineering's industrial-scale capture of CO2, will enable production of zero-carbon fuels at a price comparable to pre-tax costs in conventional hydrocarbon fuels in major markets - less than £1.00/litre.
Although production costs will be slightly higher than their fossil-fuel equivalent, the modest premium is expected to be covered by a combination of tax-waivers, market or regulatory incentives, or by major users committed to reducing emissions. In any event, amortisation through progressive reduction in carbon intensity over 30 years from 2020-2050 translates to a negligible annual increase in operating costs which can easily be absorbed by the end-user – particularly where other technical improvements improve fuel efficiency and lower its relative contribution to overheads.
On combustion, fuels synthesised from atmospheric CO2 simply return their carbon back to the atmosphere. Such 'closed-cycle' fuels are one of the very few options to power global transportation that is fully carbon-neutral and fits within the current global hydrocarbon fuels infrastructure.
In addition to hydrocarbon fuels for transportation, high energy density enables such fuels to be used as a carbon-neutral storage medium for renewable energy installation such as wind, where overcapacity to compensate for intermittent yield results in an otherwise unusable energy surplus during periods of peak generation.
One immediate market opportunity is Enhanced Oil Recovery to meet Low Carbon Fuel Standards already in force in California and under consideration elsewhere (figure 4). EOR involves the injection of CO2 into oil wells to enable or extend production. The market for EOR CO2 in the Texas Permian Basin is 50m tonnes/year, rising to 80m tonnes/year over the next decade.
Total estimated recoverable EOR reserves in the US are 89bn bbl, representing $10trn of value.
The Californian LCFS sets a maximum well-to-wheel (WTW) carbon intensity (CI), whereby regulated entities can generate credits for the production or import of low-carbon fuels, and can sell excess credits in the open market. Unlike California's cap-and-trade, LCFS value can only be generated through low CI fuels. Prices are much higher than carbon offset markets, reaching $100/tonne in 2016, and are widely expected to reach $200 by 2020 as the regulations tighten. By supplying atmospheric CO2 to EOR producers, the resulting fuels have a typically 53% lower CI which can be optimised by blending with conventional production, monetising both the commodity value of the CO2 as well as its low-carbon premium (figures 5 & 6).
DAC outperforms Brazilian bioethanol on cost, carbon intensity, land-use, domestic deployability and drop-in convenience.
Biofuels only achieve reduced carbon intensity if produced using atmospheric CO2, and for algal biofuels, this must be enriched. Only DAC meets both of these requirements. It is also locationally flexible, enabling onsite co-location in areas suitable for biofuel production with high insolation, water supplies and low-cost land – avoiding expensive pipelines. CE's aqueous system for capturing CO2 offers a large competitive advantage over alternatives because it removes the need to produce pure CO2, by feeding directly into the aqueous algal medium.
Investment in algal biofuels development is now measured in $bns, with current growth of 40% per annum
DAC also offers the option of offset sequestration via EOR, saline aquifers or mineralization. Saline aquifer capacity is sufficient for decades, and mineralization is for practical purposes almost limitless.
Sequestration offers the possibility of 100% authenticated, effectively permanent CO2 removal for carbon offset contracts, with none of the issues of baseline measurement, authentication, additionality or leakage associated with the existing voluntary and CDM offset markets. DAC can provide the platinum standard for this industry.
Carbon Engineering’s commercialisation pathway has four stages. Following successful testing and demonstration of a pilot plant in 2012, a final pre-commercilisation Demonstration Pilot Plant (DPP) was completed in Q3 2015, and has since been capturing CO2 at the rate of 500 tonnes year. The chosen size of this unit was significant: it had to be sufficient in scale that, following satisfactory performance, it would enable equipment suppliers to provide cost and performance guaranties for full-scale facilities of up to 1 million tonnes/year. Performance data gathered over the interim operating period has been used for optimisation of the complete end-to-end process, as well as inputing into the FOAK design and engineering exercises (see below). The DPP plant is shown in images 1-7.
By Q3, on site assembly of an A2F plant will have been complete, coupled to the DAC plant in an end-to-end process of CO2 capture and conversion to low carbon intensity (CI around 15%) synthetic hydrocarbon fuel (also referred to as solar fuel).
Direct Air Capture is a strategic new technology the full significance of which can only be appreciated in the context of impending seismic shifts in global climate policy.
The belated recognition that our current emissions trajectory will lead to uncontrollable climate change must spark a massively accelerated transition toward a zero carbon fuel economy and large scale atmospheric sequestration.
As key component of both, DAC represents potentially one of the most significant technological developments in industrial history’
Carbon Order, 2012
'THERE ARE NO COST-EFFECTIVE OPTIONS AVAILABLE FOR THE AVIATION SECTOR TO ACHIEVE EVEN A 50% DECARBONISATION BY 2050 OTHER THAN DAC EITHER THROUGH A2F, EOR OR SEQUESTRATION OFFSETS (VIRTUAL zERO-CARBON FUELS).
ALLOWING FOR GROWTH OF 4% PER ANNUM IN AIR TRAVEL (NET OF 1% PER ANNUM TECHNICAL IMPROVEMENTS IN FUEL ECONOMY) WOULD REQUIRE THE CONSTRUCTION OF 31 one-million TONNE DAC PLANTS A YEAR, GENERATING LICENCE FEE INCOME TO CARBON ENGINEERING IN EXCESS OF $600M FROM 2020, INCREASING ANNUALLY BY THIS AMOUNT FOR THE FOLLOWING THIRTY YEARS. FOR 100% DECARBONISATION, INCOME GROWTH WOULD BE DOUBLE THIS FIGURE'.
Carbon Order, 2014
‘Commercialization of DAC will add to our ability to make deep reductions in economy-wide emissions, and meet critical long-term climate change goals'.
SOURCE: Carbon Engineering 2013
CARBON ENGINEERING WILL BRING INDUSTRIAL-SCALE AIR CAPTURE TO MARKET, BY DESIGNING AND BUILDING THE WORLD’S FIRST AIR CAPTURE PLANT. CE'S TECHNOLOGY WILL COMPLEMENT CCS AND OTHER MITIGATION OPTIONS BY CAPTURING ATMOSPHERIC – NOT GEOLOGIC – CO2, IN ORDER TO HELP MANAGE THE 60% OF EMISSIONS THAT DO NOT COME FROM POINT-SOURCES.
CARBON ENGINEERING'S TECHNOLOGY STRATEGY IS TO DEVELOP A LOW-RISK, CHEMICAL-BASED CO2 AIR CAPTURE SYSTEM THAT MINIMIzES UP-FRONT CAPITAL COSTS. CE'S PATENTED TECHNOLOGY INTEGRATES TWO PROCESSES: AN AIR CONTACTOR, AND A REGENERATION CYCLE, FOR CONTINUOUS CAPTURE OF ATMOSPHERIC CARBON DIOXIDE AND PRODUCTION OF PURE CO2.
Demonstration Pilot Plant Construction
SOURCE: Carbon Engineering
TIMELINE TO LARGE-SCALE DAC DEPLOYMENT
Final pre-commercialisation stage $8m Demonstration Pilot Plant in B.C. completed and capturing 500 tonnes CO2/year to be coupled with on-site $14m Air-to-Fuels plant for production of near-zero-carbon diesel for local public transit network by Q2 2017
First-Of-A-Kind (FOAK) large-scale commercial plant planned for construction in 2018 for production of zero-carbon fuels using CO2 and H2 generated from electrolysis of water powered by pv, as well as sequestration for virtual zero-carbon fuels, offsets and atmospheric reduction.
Full-scale one-million tonne CO2/year facilities deployment targeted for 2020 onwards producing diesel, gasoline and jet fuel at competitive pricing for the transportation market enabling – together with other efficiency and renewable energy contributions – zero-carbon status for road, shipping and aviation sectors by 2050
Discussions underway with potential strategic partners for collaboration on development of key DAC markets for off-take supply contracts for low and zero-carbon fuels, and integration in emerging policy initiatives
‘YOU DON’T HAVE TO RE-TOOL THE US$30 TRILLION IN (GLOBAL) INFRASTRUCTURE NOW USED TO DELIVER FOSSIL FUELS’
Adrian Corless, CEO Carbon Engineering, referring to the potential for DAC synthetic fuels in ‘Canadian company opens pilot facility to pull carbon from air’, The China Post 12. 10. 2015