Plant for CO2 Extraction
In the document Sequestration of CO2 in Brines we make it clear that the technology has to be of interest to industry. Every new product or process needs gatekeepers and champions and we include details of the sequestration plant we have designed we call Syncarb in the hope of being funded or somebody else doing it. With funding we will first test it at lab scale and then build build a pilot plant before going to full scale. If you use our ideas it is mandatory that you do so as we will not be responsible for failures or accidents.
We describe the plant in relation to the important steps of carbonation and precipitation. We do not describe the further steps necessary to recover minor elements such as lithium or make sodium carbonates in a Solvay process look alike add on to Syncarb.
We note that new technolgoies are being developed all the time that will probably make the separation and concentration of lithium and other valuable elements from brines easier and therefore more commerically viable without the value of aggegate, building products, fertilizer and other by products produced by our technology. .
There are a number of reasons the extraction of calcium and magnesium should be separated early in the process as should the process of carbonation and precipitation.
1. The widely different pressure and temperature solubility and supersaturation of calcium compared to magnesium as both hydroxides and carbonates
2. A significant increase in solubility of CO2 at lower temperatures
3. A significant reduction of alkali needed at higher temperatures
4. The poisoning of calcium precipitation by magnesium due to lattice site competition.
Out ideas on plant for the precipitation of magnesium as a hydroxide then as a carbonate as well as the precipitation of calcium as a carbonate follow. Should anybody care to comment or add to what we think we would appreciate to john.harrison on +61 413993911. Don't just follow what we say, think for yourself you may be able to improve on our ideas. We are not even going to build the plant as drawn without a great deal of lab testing and the prior construction of a pilot plant. It gets expensive if you do not do that.
As several times the amount of CO2 can be dissolved in cold water at say 4 degrees than at room temperature we suggest pre carbonation and to speed the process up the gas should be around 55 psi or 3.8 bar in the tank. Tall pressurised carbonation towers are suggested in our drawings however we have yet to test what pressures the see through materials we have in mind can tolerate.
Precipitation and Concentration
Clarifyers in chemical engineering are swirl tanks in the aquaculture industry and both have workable designs for precipitation and concetration.