Rum and seaweed! It sounds like the diet of a broke pirate, and it probably was, at some point, but now researchers at the University of the West Indies Cave Hill campus and the Caribbean Centre for Renewable Energy and Energy Efficiency (CCREEE) have taken those same elements and managed to extract a viable transportation fuel from them. Yes, they managed to get a Nissan Leaf to run on a form of biofuel made from sargassum, a form of seaweed that has been plaguing Barbados’ beaches for years, along with wastewater from rum distilleries, and, just to make this even better, the rich, loamy poops of native Blackbelly sheep. There’s something in there for everyone!
The resulting fuel is essentially bio-methane, or bio-Compressed Natural Gas (CNG), and cars have been adapted to run CNG for decades. Biogas has been made from the anaerobic decomposition of biowastes before, but this particular variation is especially significant because sargassum has become such a stinky ass-pain for Barbados tourism, with vast quantities of it washing ashore and rotting in foul-smelling piles.
Initially, researchers were looking into converting sugar cane into vehicle fuel, emulating the success Brazil has had for years with their sugar cane-based alcool fuels.
While alcool fuel has been incredibly successful in Brazil, Barbados doesn’t grow sugar cane in enough quantity to really make it a viable option. While researching this option, researchers Legena Henry and her student Brittany McKenzie noticed some trucks tasked with removing the massive mounds of sargassum, and had an idea: maybe all of that miserable stuff could be converted into fuel?
After a lot of research and experimentation with sargassum, rum distillery wastewater, and anaerobic bacteria from Blackbelly sheep manure, an optimal combination was determined to yield the highest levels of usable natural gas.
A startup company named Rum & Sargassum has been founded to commercialize the fuel, and the fuel can be used in CNG-converted combustion cars (the conversion process isn’t particularly difficult, and costs about $2,500), or, as they demonstrated with their test-case Nissan Leaf, EVs. The Leaf is using a generator powered by the rum-and-sargassum fuel and using that to provide electricity to the batteries, making it, effectively, a range-extended EV, the kind we’ve been advocating here lately, only even better, because this one runs on unwanted seaweed, rum dregs, and sheep shit.
While this is likely only really effective in the very specific environment of Barbados, for that particular environment it really couldn’t be any better: Barbados wants to become carbon-neutral, importing fossil fuels is expensive, and the problem with all the sargassum is a huge deal. Now that sargassum may have actual use and value, those piles of it lining the beaches can become a resource instead of a big, stinky mess.
This also means that the next time you enjoy a rum and Coke made with Barbados rum, you’re directly helping to solve the climate crisis. You’re a hero, rummy!
Sargasso and Rum was the name of my high-school Paul Revere and The Raiders tribute band.
Running on sargassum is good. Now if we can get a car that runs on sarcasm, I’d be set.
I think the very first vehicles beyond the test vehicle that should be converted to harness this energy should be the ones within the loop; the seaweed harvesters, transport trucks, etc. Same for the vehicles dealing with the sugarcane and sheep. Hopefully there will be plenty of surplus energy to sell to the rest of the community.
I did notice one of the sponsors of the project is Bloom energy who makes NG fuel cells. Those are very efficient at turning methane into electricity.
Fuel cells make a lot of sense for small biogas because it gets the same efficiency as the largest natural gas power plant but in a size that you could actually make enough biogas for.
Instead of trucks to transport the seaweed, it should be a pipeline with a shredder next to the beach.
Which would make a lot of sense except these are tourist beaches and I doubt anyone wants to vacay next to a pipeline and shredder.
Agree about the FC though. Ideally feed the digester right into the FC and use a compressor and storage tank only to even out the flow. That would minimize compression losses.
Put the shredder out on a platform far enough offshore and maybe bury the pipeline as much as possible. Collect the seaweed with drones pulling nets. The seaweed is bad for tourism in general so the more it gets collected before it even hits the beach the better.
Its a free floating species so I think it only rots when it’s 100% dead on the beach. It may also need to be cleaned of salt which is where the brewery water comes in. Then there’s the matter of biowaste, might that be a hazard for the ocean? I used to live in San Diego and there were many beach closings due to the currents coming up from the border where multiple sewer lines dumped into the sea. That was eventually fixed with a many mile long pipeline that pushed the sewage out far enough to be someone else’s problem though.
Moving forward your idea is probably worth some thought but I think the argument is that the island is already a platform and its will be easier and more economical to collect and process the wastes on the island as well as hook into power.
I was thinking the brewery waste was to dilute the salt down to a tolerable level. The biowaste effluent that comes out at the end still has value as fertilizer. It could probably just be spread over a sugar cane field (depending on salt and heavy metal content). Some larger bio digesters have a nutrient recovery unit that can produce phosphorous and nitrogen fertilizers. The waste would be much less harmful to dump in the ocean after the P and N are removed because there would no longer be an algae bloom, but being on an island they would probably still want to use it to build a sea wall or raise the elevation of somewhere inland.
See this is why I really like this story, so much hope and potential.
Fine, I guess, but it won’t have the global impact that adding sodomy and the lash to rum did.
When “runs like shit” is a feature, not a bug.
So they got a CNG-burning electric generator that in turn charged a Nissan Leaf.
Big deal. This is not revolutionary.
Water Treatment/Sewage utilites have been powering their vehicles with methane for decades. And where do they get the methane? From the rotting sewage… aka “sewer gas”.
In my opinion, instead of what they are doing, they should be looking at collecting the methane that comes from rotting garbage and anything else that rots (like sargassum), combust it efficienty at the electric utility level and put that electricity into the grid to use for everything from powering HVAC systems, lighting, charging BEVs or anything else that needs electricty.
Not revolutionary no. But it is a creative solution.
I think it’s the NG in CNG where the revolution is happening…
Yep. I studied the economics of anaerobic digestion, published papers, designed digesters for about 10 years. The waste to gas part is nature, and finicky but not hard. The material handling and mechanical part of harvesting, the cleaning all the co2 and sulfur out of the biogas is so expensive we couldn’t get it to pencil out without big subsides. Smaller subsidies than 20 years of war in the middle east though.
It’s a fun thing to work with and a good way to get people excited about biology and chemistry, but there’s no such thing as a free lunch.
I’m here for the Quatro Testes
Does a $2k compressed gas conversion kit include a new engine? Then it is not going to work on a Nissan Leaf. Let us use our critical reading skills.
They converted 4 cars that were not the Leaf to run on CNG. To refuel the converted CNG cars requires a compressor pump that requires a generator running to produce the needed electricity. The generator is also used to power the other required electrical needs to produce the biofuel, like pumping the spent sludge out of the tank. The Leaf is literally just plugged into the generator while it is powering everything else.
Rum, Seaweed, And Sheep Poop – Sounds like the gifts of the Three Wise-Ass Men
So, they distill the stinky shit to make ethanol. Why not burn that in a converted combustion engine instead of an electric Nissan Leaf?
They are letting the stinky shit rot in a container with no oxygen, which produces methane. This methane is then put into a compressed tank and burned in a converted combustion engine.
But why is the rum gone?
From a whole carbon capture perspective, would this not be intentionally removing material from sequestering by burning it – and therefore releasing CO2/greenhouse gases?
I wonder from a kWH produced, if someone could do a backcheck on most efficient methods at smallscale.
That’s true for any biofuel though. The advantage to them is that sargassum, sheep shit, and rum are constantly being created so it becomes a circular system, unlike fossil fuels that take so long to form that once you burn them you’ve essentially released the carbon permanently.
It’s not a perfect system (although I feel like I can promise a Nobel prize to the first person who builds a perpetual motion machine based on sheep shit), but given that all of the ingredients are otherwise waste products that would have eventually broken down into greenhouse gas on their own, there seems to be very little drawback.
Leaving the seaweed to rot on the beach releases greenhouse gasses, both CO2 and methane. Collecting the seaweed to rot in a controlled container releases both CO2 and methane as well, but the methane gets combusted into CO2 before it is released to the atmosphere. Methane is a more potent greenhouse gas, so this process avoids releasing some greenhouse gasses to the atmosphere because much less methane is released.
All those things, the seaweed, the poop and the distillery runoff will rot anyway and without this intervention rot directly into the atmosphere where the methane will do more damage than CO2.
Big deal, I invented that basic concept years ago – throw a sheep, or any animal, really, elephant, whale, etc, into an incinerator, use heat to make steam to drive a turbine, 100% renewable electricity. Use wild caught, so no costs in livestock raising, keep them alive so no processing expense, either
High-fat, and large animals would burn longer.
“powered by whale”
If your day is gone, and you want to ride on, Methane!
It don’t lie.
Person greeting partner arriving with the new car: “What the HELL is that smell??”
Proud proactive partner: “They said it ran on sheep shit & seaweed, so I filled up!” Broad smile slowly crumbling…
Based on the topshot, I assume “Rum and Stinky Seaweed” is now a new regular segment for Torch to do weekly posts on, maybe as a replacement for Mercury Monday, given the timing.
Really should have been Stinky Saturday but Torch couldn’t wait. (or he’s 2 days late)