Patent Application
20080276677
The present invention lies in the field of climate control technology, and more specifically, by adapting (1), Solvay process to absorb carbon dioxide from fossil fuel combustion; and (2), without regenerating ammonia from ammonium chloride of said Solvay process, and using the ammonium chloride so obtained as aqua marine fertilizer for massive reduction of carbon dioxide already in the atmosphere, to an extent of producing biomass hundreds times the weight of ammonium chloride.
United State burns annually close to one billion tons of coal for power generation. China and India burn nearly the same amount and may soon surpass United States. Expert reports stated that severe consequence on human society may result if greenhouse effect is left uncontrolled or improperly controlled. United States Department of Energy has demonstration projects that are capable to absorb better than 99 percent of carbon dioxide by scrubbing the flue gas with low molecular weight amines. The amines are regenerated for reuse and carbon dioxide sequestrated by storing underground or used for enhancing crude oil production. However, none of the existing carbon dioxide sequestration systems and methods has large enough extent to reverse the carbon dioxide produced by human beings before the disaster strikes.
Ernest Solvay invented the ammonia-soda process circa 1860's that bears his name. The reaction is carried out by passing concentrated brine through two scrubbing towers. In the first, ammonia bubbles up through the brine and is absorbed by it. In the second, carbon dioxide bubbles up through the ammoniated brine, and sodium bicarbonate precipitates out of the solution
The worldwide production of soda ash in 2005 has been estimated at 41.9 million metric tons. Solvay-based chemical plants now produce roughly three-fourth of this supply, with the remainder being mined from natural deposits.
The Solvay process as it is practiced today, discharges carbon dioxide into the atmosphere via (1) converting sodium bicarbonate into soda ash, (2), producing quicklime from fossil fired kiln for recovering ammonia from ammonium chloride, and (3), using natural gas based hydrogen to produce ammonia by Haber Bosch Process.
The carbon dioxide sources cited in the last paragraph can be avoided if (a), sodium bicarbonate (very huge quantity) is shipped back and buried in coal pit, (b), ammonium chloride, without regeneration, is shipped ocean bound and used as aqua marine fertilizer, and (c), hydrogen from water electrolysis using photovoltaic solar electricity.
Steps (a) and (b) can be achieved today. Step (c) will be a reality several decades from now.
This comprises the method of carbon dioxide double-sequestration of this invention.
By molecular weight comparison, based on one billion tones of coal (carbon) per year, 3.67 billion tones of carbon dioxide is sequestrated in 7.0 billion tons of sodium bicarbonate that consumes 1.417 billion tons of ammonia, and produces 4.46 billion tons of ammonium chloride fertilizer byproduct, potentially producing greater than 400 billion tons of dry carbon hydrate biomass with carbon content greater than 160 billion tons.
This comprises the carbon dioxide double-sequestration system of this invention.
It is well known to seamen before Christopher Columbus discovery of America that marine aqua culture grow only in shallow sea water along the shore line. Consequently, the majority of the ocean surface is not engaged in carbon dioxide uptake. The most preferred embodiment of a natural carbon dioxide sequestration system is to enlist large area of lightly vegetation-populated deep ocean surface and cultivate it with ammonium chloride fertilizer and other trace nutrients.
Said preferred embodiment is comprised of a first and direct sequestration process, wherein two scrubbers are connected in sequence; and a second and natural sequestration process, wherein deep water ocean agriculture cultivation is practiced. In the first scrubber, saturated brine of sodium chloride solution is counter flown downwardly from the top against ammonia gas flowing upwardly. In the second scrubber, ammonia brine from first scrubber is counter flown downwardly from the top against after-combustion flue gas flowing upwardly. The chemical reaction occurring in the second scrubber is NaCl+NH.sub.3+H.sub.2O+CO.sub.2.fwdarw.NaHCO.sub.3+NH.sub.4Cl.
Said sodium bicarbonate, being slightly soluble in aqueous ammonium chloride solution, is allow to separate by a separation means. Said sodium bicarbonate solids is shipping return-bound with the empty coal train and buried in coalmine pits for future use. Said ammonium chloride solution is shipping ocean-bound for deep water aqua marine vegetation growth.
Said second sequestration process is comprised of a nitrogen fertilizer composed of essentially of ammonium chloride blended with a trace amount of nutrients suitable for a particular spices of aqua marine algae.
