pstarr wrote:Video - The technology, hydrothermal liquefaction, mimics the geological conditions the Earth uses to create crude oil, using high pressure and temperature to achieve in minutes something that takes Mother Nature millions of years.
Otherwise known as thermodepolymerization>Fischer-Tropsch: has been tried (on turkey guts, human waste etc.) and failed to return a net-positive energy. The high-pressure and temperature are generated by burning COAL or PETROLEUM . . . so why not just use COAL and PETROLEUM?
There's that EROEI bugaboo . . . always ruining the techies fun. Bastards
eclipse wrote:So the problem is we need a cubic mile of oil a year, or a cube 1.6km on a side.
https://en.wikipedia.org/wiki/Cubic_mile_of_oil
Tim Flannery has suggested kelp as a CO2 sequestering mechanism, where 9% of the oceans are gargantuan kelp farms, probably with robotised harvesting systems, and this soaks up 40GT of Co2 a year.
40GT per year is 10 times the oil refined in 2008.
https://www.statista.com/statistics/265 ... tric-tons/
The real problem, though, is if we're trying to sequester kelp farms the size of 9% of the ocean's, where do we put it all? We've already seen that we're burning just 10% for oil! (I'm seriously weirded out thinking of biomass as an oil replacement! I gave that up years ago!) What to do with the other 90%? Apparently it works out to about just under a cubic km of dried fibre every week!
What about biochar to help sequester CO2 in farmland soils?
What about to cows to feed them and eliminate their methane burps?
Indeed, if it can feed all our cows, and they don't need grass or other supplements but can live of kelp? (I don't know!?) Then it could reduce their grazing impact on the environment as well. I wonder what other ruminants basically just need biomass that their 4 stomachs can break down? Goats? Sheep?
If we could harvest 9% of the world's oceans in kelp, the world's oil multinationals would be saved. That leaves a bad taste in my mouth, as I had hoped electric transport would clear up the air over our cities.
vtsnowedin wrote:Before you worry about which nine percent of the worlds oceans to convert to kelp farms you might try a single square mile somewhere easy and prove the concept start to finish. Kelp taking CO2 out of the water is simple enough but how you keep the carbon from re entering the atmosphere and how that saves any oil or oil companies is not clear.
In a study conducted by the Philippines it showed that plots of approximately one hectare can have a net income from eucheuma farming that was 5 to 6 times that of the minimum average wage of an agriculture worker. In the same study they also saw an increase in seaweed exports from 675 metric tons (MT) in 1967 to 13,191 MT in 1980, which doubled to 28,000 MT by 1988.[12]
https://en.wikipedia.org/wiki/Seaweed_farming
pstarr wrote:vtsnowedin wrote:Before you worry about which nine percent of the worlds oceans to convert to kelp farms you might try a single square mile somewhere easy and prove the concept start to finish. Kelp taking CO2 out of the water is simple enough but how you keep the carbon from re entering the atmosphere and how that saves any oil or oil companies is not clear.
You do not keep the carbon from entering the atmosphere. It happens all on its own.
Kelp is cellulose, a carbohydrate. When a kelp dies its carbs remain. Just like a tree. Another example of carbon-dioxide fertilization, aka 'global greening'.
“The most exciting, if least well understood, of all the biological options involve the marine environment. Seaweed grows very fast, meaning that seaweed farms could be used to absorb CO2 very efficiently, and on a very large scale. The seaweed could be harvested and processed to generate methane for electricity production or to replace natural gas, and the remaining nutrients recycled. One analysis shows that if seaweed farms covered 9% of the ocean they could produce enough biomethane to replace all of today’s needs in fossil fuel energy, while removing 53 gigatonnes of CO2 (about the same as all current human emissions) per year from the atmosphere. It could also increase sustainable fish production to provide 200kg per year, per person, for 10 billion people. Additional benefits include reduction in ocean acidification and increased ocean primary productivity and biodiversity. Many of the technologies required to achieve this are already in widespread use, if at a comparatively minuscule scale.”
My understanding is kelp forest will only grow on the continental shelf, so forget the whole surface of the ocean stuff.
Then you have to add in the fact that Kelp do have water temperature and sunlight requirements that limit how much of the ocean shelf could viably be used to farm kelp.
Third, not all wildlife does well in kelp forest regions, so you need to reserve good size chunks of the shelf for sea grass where the Manatees can graze and all the other variations that you get in the continental waters.
Put all those factors together and MAYBE you can grow Kelp forest on 10 percent of the continental shelf or about half a percent of the total ocean surface.
That is still an admirable thing to do because Kelp is a great food source, not just for human beings but also for grazers like cattle and omnivores like swine.
Counting on it to replace all fossil fuels? Not so much.
eclipse wrote:Bottom line?
I haven't found a peer-reviewed source that says we cannot grow kelp in 9% of the world's oceans.
Seaweed farms alone have the capacity to grow massive amounts of nutrient-rich food. Professor Ronald Osinga at Wageningen University in the Netherlands has calculated that a global network of "sea-vegetable" farms totaling 180,000 square kilometers -- roughly the size of Washington state -- could provide enough protein for the entire world population.
The goal, according to chef Dan Barber -- named one of the world's most influential people by Time and a hero of the organic food movement -- is to create a world where "farms restore instead of deplete" and allow "every community to feed itself."
But here is the real kicker: Because they require no fresh water, no deforestation, and no fertilizer -- all significant downsides to land-based farming -- these ocean farms promise to be more sustainable than even the most environmentally-sensitive traditional farms.
http://www.theatlantic.com/internationa ... ge/248750/
eclipse wrote:So these Professors are just making it up?Seaweed farms alone have the capacity to grow massive amounts of nutrient-rich food. Professor Ronald Osinga at Wageningen University in the Netherlands has calculated that a global network of "sea-vegetable" farms totaling 180,000 square kilometers -- roughly the size of Washington state -- could provide enough protein for the entire world population.
The goal, according to chef Dan Barber -- named one of the world's most influential people by Time and a hero of the organic food movement -- is to create a world where "farms restore instead of deplete" and allow "every community to feed itself."
But here is the real kicker: Because they require no fresh water, no deforestation, and no fertilizer -- all significant downsides to land-based farming -- these ocean farms promise to be more sustainable than even the most environmentally-sensitive traditional farms.
http://www.theatlantic.com/internationa ... ge/248750/
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