CO2 capture system
HVC is currently installing a capture installation for Bio-CO2 in Alkmaar as a demo trial for the bio-energy power plant. The Bio-CO2 will be tested later this year by greenhouse growers in the far north of the province of Noord-Holland.
HVC is the first company in the Netherlands to capture CO2 from a bio-energy power plant and to convert this into liquid CO2 for horticulturists in the region. HVC captures the Bio-CO2 directly from flue gases, thus reducing its own CO2 emissions. Linked to a bio-energy power plant, the installation will prevent approximately 4 kilotons of CO2 from being emitted on annual basis. Thanks to the Bio-CO2 greenhouse growers in this region will no longer need to rely on the fossil fuel natural gas. There is a particular need for this in hot summer weather. A single ton of Bio-CO2 will enable you to save half a ton of CO2 derived from natural gas.
The construction of the CO2 demo trial installation is an intermediate step for building a larger capture installation as a regional source of Bio-CO2 and to attain the goals of the Noord-Holland Green Deal CO2 for greenhouse horticulture companies. The external supply of CO2 is a key precondition for enhancing the sustainability of the greenhouse horticulture industry. Robert Kielstra, Director of Energie Combinatie Wieringermeer (ECW) and representative of the greenhouse horticulture companies at Agriport: ‘Capturing CO2 is a prime example of the circular economy. Although this is just a trial installation, this step will mean a giant step forward in sustainability – particularly after a scale-up – because it contributes to reducing the use of natural gas in the greenhouse horticulture industry.’
In addition to supplying Bio-CO2 to greenhouse growers, HVC’s bio-energy power plant will also provide 4,800 customers in Alkmaar, Heerhugowaard and Langedijk with heat. The ultimate goal is to provide 15,000 households and commercial enterprises with green, sustainable heat. The bio-energy power plant, which is fired by waste wood, is in fact nothing but a huge central heating boiler for the entire region. When waste wood is burned, steam escapes which is subsequently used to heat water. This water is then transported to households and businesses in the region via heat pipelines. The cooled-down water will return to HVC, where it is heated up again.
Source: HVC. Photos: HVC/ Marc Dorleijn.
The University of Twente recently developed a new technology to cheaply and efficiently capture CO2 from ambient air. The CO2 thus captured is used by the university to grow algae, but can also be used to store solar and wind energy in a closed cycle.
The ‘CO2 air capture unit’, the machine used by the University of Twente to capture CO2 from the air, was designed to capture at least 500 grams of CO2 from the air per day. The CO2 is present in the air a strongly diluted form (approximately 400ppm). As a result, around 1400 cubic meters of air is needed to get one kilo of CO2.
The test set-up used by the university captures CO2 from the ambient air rather than specific flue gases. The capacity of the new air capture unit can be compared to that of four big trees, each planted on a surface area of 50 square meters. The University of Twente will be using the device that captures CO2 from the air to grow algae, a valuable resource for food ingredients and various chemicals in it the bio-based economy. The growth rate of the algae is increased drastically under the influence of CO2.
To achieve the current capacity with which the university aims to capture CO2 from the air the researchers use sorbents, small particles to which CO2 binds. In an ‘adsorber’, the researchers bring non-charged particles into contact with a huge air flow that moves through the unit with a very low pressure drop. As soon as the particles are charged with CO2, they travel up to the top of the unit, which is about six meter in height. From there, gravity propels them to flow down through a heated column, the ‘desorber’, where they deliver their CO2 load. After this, the sorbents will repeat the same cycle again.
Opportunities for greenhouse horticulture
The CO2 -rich gas subsequently travels from the air capture unit to the algae reservoir. Although cooling down and heating requires energy, the net energy consumption of the capture unit is relatively low. The energy costs (estimated at about 75 euros per 1,000 kilograms of CO2) are relatively limited and in line with the current prices on the market for CO2. It is expected that the greenhouse horticulture industry will able to benefit from this technology. “The use of ‘CO2 air capture’ makes it possible to produce CO2 more sustainably, no matter where in the world”, says project leader Dr Wim Brilman.
Sustainable natural gas
The CO2 thus captured can also be used to store solar or wind energy. Using CO2 from the air, together with hydrogen, it is possible to produce methanol and sustainably produced methane (‘natural gas’). Thanks to this interim step, peaks in the supply and demand of energy can be responded to adequately, without any need for batteries. This ‘natural gas route’ will be tested in a ‘Power-to-Gas’ system connected to an existing apartment building complex in Rozenburg.
Source: NWO/Universiteit Twente. Photo: Gijs van Ouwerkerk.
The Swiss start-up Climeworks is developing a system that extracts CO2 out of the air for greenhouse horticulture purposes. The system will be tested during a three-year pilot and should be able to capture some 2 to 3 tons of CO2 on a daily basis. This will be piped to a nearby greenhouse to boost the growth of lettuce, cucumbers and tomatoes, according to New Scientist magazine.
The system, called Direct Air Capture (DAC), captures air in closed spaces, such as submarines and space capsules. The captured ambient air is pushed through a fibrous sponge-like filter material that has been impregnated with chemicals derived from ammonia. Once the filter is saturated, the gas will be released by warming it with the heat which is in this case generated by a nearby municipal waste incineration plant. The CO2 thus released is then piped to a 4-hectare greenhouse.
According to calculations made by the American Physical Society the cost of capturing CO2 on this scale would be 600 dollars a ton, says Climeworks COO Dominique Kronenberg. The Swiss start-up also expects to equal that and eventually get costs down well below that. At that price, taking C02 out of the air is more expensive than removing it from the flue gases of industrial facilities and power plants, where the gas is up to 300 times more concentrated.
Despite the high price, Kronenberg notes the many advantages to the DAC process. ‘The advantage of taking it out of the ambient air is that it can be done no matter where you are on the planet. We are not dependent on a source of CO2, so neither will we need to make high costs to transport the CO2 to the greenhouses.’ Climeworks will be using funding from the Swiss Federal Office of Energy to fine-tune the system. The objective of the three-year pilot period is to make the system run more cheaply and efficiently and, in doing so, enable the company to gain a solid foot on the market.