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CO2 capture for algae cultivation. A new patent !! Posted by Richard on Fri September 24 2010 12:26:28 AM 8

CO2 capture for algae cultivation . A new patent !!Here it is an all new reversible co2 capture process to be patented. To all researchers it is a great time. The time when u patent your invention. Cheers !


The  invention focuses on two main factors responsible for the high cost of liquid fuel from aquatic biomass, the high cost of CO2, and the high cost of converting aquatic biomass to bio-oil. 

 The most common form of aquatic biomass is obtained from growing algae. 




When there is enough available sun light, the availability of CO2 generally is the rate determining step on the production of aquatic biomass. Although there is an unlimited supply of CO2 in the earth's atmosphere, the concentration of CO2 in ambient air is low. The gas is also poorly soluble in water. 

It has been proposed to increase the growth rate of aquatic biomass by bubbling CO2 through an algae growing pond. Although this technique significantly increases the production of aquatic biomass, the cost of CO2 gas considerably adds to the cost of aquatic biomass so produced. 

It is possible to use for the production of aquatic biomass CO2 produced in the combustion of fossil fuels, such as in coal, oil or gas-fired power plants.

 However, it is rarely possible to construct algae growing ponds of a meaningful size in the immediate vicinity of a power plant.


 Also, many power plants are not located in areas that have the required amount of sunshine required for the economic production of aquatic biomass. Even if all these requirements are met, power plants tend to produce most of their CO2 by-product at night and during the winter time, that is, when the demand for CO2 from the algae-growing ponds is low. 

There is therefore a need for a process for producing aquatic biomass that has a reduced dependency on the time and location of the production of CO2 in the combustion of fossil fuel. 

This is addressed by the present invention, which provides a plant for producing aquatic biomass comprising:
a) a pond adapted for growing aquatic biomass;
b) a system for providing CO2 to said pond; 
and
c) a CO2 capturing material capable of reversibly capturing CO2 



The reversible capture of CO2 may be based on temperature. Materials particularly suitable for use in element c) are those that capture CO2 when contacted with CO2 at a relatively low temperature, for example a temperature below 200 dec C., and release CO2 when heated to a more elevated temperature, for example a temperature above 250 deg C. 

Preferred CO2 capturing materials are those comprising an inorganic oxide. Suitable examples include natural and synthetic clays; oxides and hydroxides of aluminum, magnesium, calcium; alumina/magnesia mixtures; meixnerites; hydrotalcite and hydrotalcite-like materials; and mixtures thereof. 

The CO2 capturing material is loaded with CO2 at or near a location where CO2 is produced, for example as a by-product of some other process, such as the generation of electricity. 


After loading with CO2 the material is shipped to the plant for producing aquatic biomass, where it is charged to a suitable reactor for release of the CO2. Importantly, the material may temporarily be stored until the CO2 demand of the plant justifies its use. 



Although the invention permits the transportation of CO2 over any distance, in the form of the CO2 capturing material loaded with CO2, it will be understood that transportation distances are preferably kept short. 



The invention may also use CO2 produced in the combustion of a renewable resource, such a bio-fuel. In this case the process results in a net reduction of the output of CO2, thereby off-setting CO2 production from fossil fuels elsewhere on the planet. The off-set results in valuable carbon credits, which may be traded in the market for such credits. 




The pond adapted for growing aquatic biomass preferably has a depth of from 10 to 100 cm. Depending on the algae species being grown, the pond may be filled with sea water or fresh water. The use of sea water is preferred, as its use does not divert precious fresh water supplies. 



CO2 is released from the CO2 capturing material by, for example, heating the capturing material in a suitable reactor to a temperature at which the captured CO2 is released. The capturing material is hereby regenerated. The regenerated capturing material may be shipped back to the CO2-producing location, for re-use. 



CO2 produced in the reactor is pumped to the pond for growing aquatic biomass, and bubbled through the water contained in the pond through suitable nozzles. Preferably the nozzles are located near the bottom of the pond. 



It is desirable to tune the amount of CO2 provided to the pond to the amount the algae are capable of converting. On an annual basis it is estimated that a pond may produce from 100 to 400 metric tons of aquatic biomass per hectare (104 m2) per year.


 This corresponds to 10 to 40 kg per m2 per year. About two thirds of this mass comes from CO2 (the other one third comes from water consumed in the photosynthesis process). Therefore a pond consumes from about 6.7 to about 27 kg CO2 per m2 per year. 



The consumption of CO2 per hour fluctuates with the amount of sunshine available at any given point in time, and with the amount of algae present in the pond. The skilled person will be able to estimate the CO2 consumption.



 It is possible to provide a computer-control based process, which uses the brightness of the sunlight and the amount of biomass in the water (based on, for example, turbidity) as input parameters, and which provides the CO2 demand as an output parameter. 

The invention further comprises a method for producing aquatic biomass comprising the steps of: [0042
  • a) providing a pond containing water and suitable nutrients for growing aquatic biomass; [0043]b) providing algae for growing in the pond; [0044]c) providing light shining on the pond; [0045]d) providing CO2 to the pond from a CO2 capturing material capable of reversibly capturing CO2. 

    Preferably the algae used in step b) comprise micro-algae. 

    The light used in step c) preferably is natural sunlight. 

    Preferred CO2 capturing materials are those comprising an inorganic oxide. Suitable examples include natural and synthetic clays; oxides and hydroxides of aluminum, magnesium, calcium; alumina/magnesia mixtures; meixnerites; hydrotalcite and hydrotalcite-like materials; and mixtures thereof. 

    source http://www.faqs.org/patents/app/20100233786