Taking the fizz out of carbon dumps: ONC in Australia plans to earn carbon credits using urea, from natural gas, as an ocean fertiliser
Posted by gmarkets on 20 September, 2007
Despite some concerns, the Ocean Nourishment Corporation in Australia was moving ahead with its plans to use urea as an ocean fertiliser, wrote Ian Jones, head of the Ocean Technology Group at the University of Sydney, Australia, and director of the ONC in New Scientist (15/9/2007, p.44). Urea from natural gas: Jones envisages factories making 2000 tonnes of urea per day from natural gas. This would then be dissolved in seawater and pumped through a pipe laid on the seabed at the edge of the continental shelf. Vertical risers attached to the end of the pipe would then release the urea at a depth of 50 metres, from where it would diffuse into the sunlit layer.
20sq km of plankton per factory: Each factory could maintain an area of about 20 square kilometres of plankton, at densities of about 200 micrograms per litre, said Jones, which is much less than the density produced in a toxic plankton bloom caused by pollution or nutrient run-off from land.
Part of carbon-trading by 2008? Taking into account the CO2 created in the production of the urea, Jones estimated that 1 tonne of nitrogen could sequester 12 tonnes of CO2 — so the output of each plant could sequester 8 million tonnes of CO2 each year, at a cost of US$10 to US$15 per tonne. Jones hopes that the company could be taking part in carbon-trading schemes by 2008.
Testing off Phillippines, Malaysia: The ONC team was currently working on a number of small test sites, attempting to demonstrate that adding a macronutrient like urea, in some cases in combination with phosphate, really can boost plankton levels. Later this year it plans to conduct its first large-scale field trial, releasing 500 tonnes of dissolved urea off the coast of the Philippines. This will be followed by a trial involving 1000 tonnes of dissolved urea off Malaysia.
New Scientist, 15/9/2007, p. 44