Ingeniører: Vi kan producere olie af våde alger på under en time
more_vert
close

Få de daglige nyheder fra Version2 og Ingeniøren. Læs mere om nyhedsbrevene her.

close
Ved at tilmelde dig accepterer du vores Brugerbetingelser, og du accepterer, at Teknologiens Mediehus og IDA-gruppen lejlighedsvis kan kontakte dig om arrangementer, analyser, nyheder, job og tilbud m.m. via telefon og e-mail. I nyhedsbreve, e-mails fra Teknologiens Mediehus kan der forefindes markedsføring fra samarbejdspartnere.

Ingeniører: Vi kan producere olie af våde alger på under en time

Et laboratoriet under det amerikanske energiministerium omdanner nyhøstede og våde alger til råolie på under en time. Ingeniørerne, der har udviklet den kemiske proces, håber, at udviklingen kan bane vejen for kommerciel produktion af brændstof fra alger.

»Høje omkostninger er den store forhindring for alge-baserede brændstoffer. Vi tror, at den proces, vi har skabt, vil bidrage til at gøre produktionen meget mere rentabel,« siger Douglas Elliot, der har ledet holdet bag forskningen på det amerikanske energiministeriums Pacific Northwest National Laboratory, i en pressemeddelelse.

Ifølge forskerne kræver de fleste andre nuværende teknologier nemlig, at algerne skal tørres, før de kan omdannes til olie. Tørringen er meget energikrævende, og derfor har alge-olieproduktionen været for dyr, selv om alger længe har været anset som et potentielt grønt alternativ til fossil olieudvinding.

Læs også: Lovende algeteknologi på Lolland for dyr at teste i stor skala

Men nu er det lykkedes ingeniører og forskere at forenkle produktionen ved at kombinere flere kemiske trin i en kontinuerlig proces, og kan hælde nyhøstede alger med et vandindhold på til 80-90 procent direkte i den kemiske reaktor.

Våde alger giver flere fordele

Ved hjælp af den nye proces bliver forskerne også i stand til at udvinde brugbar gas fra vandet, ligesom både det overskydende vand og de næringsstoffer, som det indeholder, kan bruges til at dyrke flere alger, hvilket reducerer omkostningerne yderligere.

På den måde kommer der fire forskellige produkter ud af processen:
* Råolie, der for eksempel kan laves om til flybrændstof
* Gas, der kan bruges i elproduktion eller komprimeres til brændstof til køretøjer
* Rent vand, der kan bruges i algeproduktionen
* Næringsstoffer som kvælstof, fosfor og kalium, der er vigtig for dyrkningen af algerne.

Læs også: Enzymer skal hente biobrændstof og foder i alger

Teknologien fjerner samtidig behovet for en kompleks behandling med opløsningsmidler såsom hexan for at udvinde olien fra algerne, som ellers bruges i de mest almindelige forarbejdningsmetoder. PNNL-holdet bruger i stedet hele alger og udsætter dem for varmt vand under højt tryk for at udvinde biomassen til flydende og gasformigt brændsel.

Efterligner jordens naturlige proces

Forskerne fra Pacific Northwest National Laboratory bryster sig af, at deres system kører uafbrudt og forarbejder omkring 1,5 liter våde alger i timen, hvor andre ifølge pressemeddelelsen må nøjes med små portioner af gangen.

Højtrykssystemet kører på omkring 350 grader og med et tryk på 3000 PSI. Det er ifølge forskningsleder Douglas Elliot hverken let eller billigt at bygge systemet, hvilket er ulempen ved teknologien, selvom besparelserne i den anden ender med at gøre det til en god forretning.

»Det er lidt ligesom at bruge en trykkoger, men de tryk og temperaturer vi anvender, er meget højere. I en vis forstand efterligner vi jordens proces, der naturligt omdanner alger til olie i løbet af millioner af år. Vi gør det bare meget, meget hurtigere,« siger Douglas Elliot.

Læs også: Her er anlægget, der forvandler alger til bio-flybrændstof

Forskerholdet fra Pacific Northwest National Laboratory har i gennemsnit omdannet mere end 50 procent af algernes kulstof til energi i form af råolie, og nogle tilfælde så meget som 70 procent. Genifuel Corp, en biobrændselsvirksomhed fra Utah, har licens på teknologien og arbejder nu sammen med en industripartner på at bygge en pilotfabrik.

Pacific Northwest National Laboratorys video om processen

sortSortér kommentarer
  • Ældste først
  • Nyeste først
  • Bedste først

og så er elbilerne måske endnu engang ude. Men hvornår får vi et forsøgsanlæg i Danmark og hvornår for vi anlæg, som kan producere olie til menigmand, så der kan komme noget i bilerne og traktorrene?

Jens

  • 1
  • 8

såvidt jeg ved er den amerikanske forskning stærkt finansieret af forsvaret, som tænker mere funktionelt end omkostninger.

1,5 liter/timen er jo fint, men alt er jo relativt. Der går nok 10+ år før det kommer i nærheden af bedre og billigere alternativer.

  • 0
  • 0

1,5 liter våde alger i timen? Er der overhovedet et netto energioverskud? Processen virker ret energitung.

Jeg savner i den grad information om, hvor meget energi de får ud af anstrengelserne, samt hvor meget energi de putter i processen.

  • 11
  • 0

Hvad baserer du energitung på. Hvis det er tryk og temperatur du tænker på, så er de her teknologier typisk baseret på en hvis energi bevarelse i processen, især da et output af olie eller gas på 300 grader eller 300 bar ikke umiddelbart lyder fornuftigt.

Det ville dog være rart med en sammenligning af de tilsvarende danske teknologier der også fungerer ved lignende tryk og temperaturer.

  • 1
  • 0

Dozens of reasons why Algae will never replace Oil
http://energyskeptic.com/2011/algae/
Algae
The best use for algae is not biofuels but as a way to store the carbon dioxide from coal power plants, as described in Benemann’s 2003 “Biofixation of CO2 and Greenhouse gas abatement with microalgae – Technology Roadmap.
This is a quick summary of the problems with making fuel from algae:
It’s too expensive
• $1,000 per barrel, According to Jerry Brand, Professor of Energy studies in the College of Natural Sciences, University of Texas.
• The U.S. Navy has contracted to pay $12 million for 450,000 gallons: $27 per gallon in 2012 (Savage)
• Solazyme in South San Francisco, sold the U. S. Navy algal fuel for over 8.5 million dollars of subsidy produced algae biofuel at $424 a gallon (that’s $17,808 per BARREL 424 * 42 gallons/barrel).
• According to a 2010 research study by the Lawrence Berkeley National Laboratory, producing fuel from algae grown in ponds at scale would cost between $240 and $332 per barrel.
• GreenFuel Technologies method is not be economically feasible due to fundamental thermodynamic constraints — even with flawless technological implementation the cost would be $800 per barrel.
The cost of algae food continues to be a problem. The cheapest food is Brazilian sugar cane, and that is still too expensive. If the food is going to come from sewage, then that limits the number of places algae can be grown to near sewage plants (providing there’s enough land to do that).
Because of high costs, 18 years of algae hydrogen and biodiesel fuel research was terminated (after two decades) by the National Renewable Energy Laboratory as described in John Sheehan et al. 1998. “A Look Back at the U.S. Department of Energy’s Aquatic Species Program—Biodiesel from Algae”. Prepared for: U.S. Department of Energy’s Office of Fuels Development. One of the reasons NREL stopped the algae biofuel program was that it was very obvious that the nutrients being added to grow the algae was costing far more than any oil that could ever be produced.
“The energy cost of extracting algae is 10 times the energy cost of extracting soybean oil,” according to Riggs Eckelberry, CEO of originoil.
Issues with open ponds
• Algae need light to survive and grow, to get adequate light, the pond can only be six-inches deep, so ponds have to be large, which adds to construction and land costs.
• This limits the species that can be grown, since local conditions will determine survivability, which means you must grow local algae that can survive in this pond, not the best possible algae that has a lot of fat that result in more oil production.
More energy is used to make algae biofuel than is created in fuel (EROEI):
1. Keep water in ponds or plastic tubing (photobioreactors) within a narrow range of optimal temperature no matter how hot or cold the outside temperature is. Where there’s light, there’s heat — algae in plastic photobioreactors will cook rather than grow.
2. Algae diseases and infections (takes energy to remove them)
3. Algae predators (takes energy to kill them)
4. Keep competing low-fat strains of algae, bacteria, and other water plants out and kill them (but not the good fatty algae)
5. Prevent overcrowding
6. Keep pH levels constant
7. Keep saline levels constant
8. Pump water into the ponds
9. Keep water aerated and circulating
10. Keep water levels constant despite evaporation and rainfall
11. Purify the water
12. Inject CO2
13. Remove waste oxygen
14. Feed the algae: make, transport, and deliver nutrients such as nitrogen and phosphorous
15. Harvest algae — a very small fraction of the overall water volume.
16. Separate algae fats from water, protein, carbohydrates etc.,
17. Sterilize strainers after processing
18. It takes energy to dry out the algae biomass
19. Algae oil goes rancid – it takes further processing energy to extend its shelf life.
20. It takes energy to build an algae pond, and its harvesting infrastructure and maintenance
21. Treat waste water
22. Infrastructure to take the waste water somewhere
23. Bio-engineered super-algae may be even more vulnerable to disease and predators than the hardy, tested-by-nature natural strains used now
24. Energy to make plastic tubing, transport the tubing to the algae factory, algae filters, the food for the algae and the food, fuel, housing, car to get to work, 16+ years of education, and so on of the staff in all segments of the algae industry; the trucks and trains transporting the algal fuel to vehicles, the oil refineries for equipment to add algal biofuel to gasoline, mining, smelting, fabricating, and delivering anything in the factory or pond made of metal as well as all the machinery and factories required to fabricate the metal object, and so on.
Where’s the land?
1. It must be flat land that can be flooded. Most suitable land that’s flat is already being used to produce food, growing algae for biofuel competes with food production.
2. The land with the best sunlight typically has no water, i.e. deserts.
3. The land must be near a lot of water that doesn’t compete with cities and agriculture.
4. The amount of land required to produce meaningful amounts of fuel could destroy ecosystems – just like natural gas fracked water. That means algae water needs to be cleaned up at a a waste water treatment facility, which limits the possible sites to place an algae farm.
5. Where is there an area of land that gets plenty of sunlight but doesn’t get cold at night? If it gets cold, the energy to heat the algae will use more energy than what’s eventually produced.
6. If the land is far from cities, the energy to transport the algae biofuel could be more than the energy used to deliver it.
Will the methane from the anaerobic sediments increase CO2 emissions?
Does it scale up?
1. Algae that do well in the laboratory usually don’t survive in the field
2. Algae that are high-fat reproduce slowly.
3. Enclosed facilities use polycarbonate, which lasts only 10-15 years
4. How can you justify the expense of enclosed facilities, the time and expense of keeping the innards clean and preventing algae sticking to them?
5. Bioreactors that are efficient in the lab can’t be scaled up to an industrial level
6. Algae produce oil to protect themselves from long periods of darkness (night) and lack of food. But when in this stress mode, they grow very slowly. To try to make them grow faster goes against their very nature!
7. Not one algae producer has been profitable or produced useful quantities of oil as of October 2011.
8. The only companies that make money on algae today are the ones who harvest omega-3 fatty acids for nutritional supplements at a price much higher than the cost of crude oil, or for use in cosmetics.
9. Nothing but failure so far after decades of trying
10. Japan also spent hundreds of millions of dollars trying to make algae into fuel, and didn’t succeed.
Too many technical hurdles
8 Mar 2013. Exxon at least 25 years away from making Algae (Bloomberg). “Exxon Mobil Corp. (XOM)’s $600 million foray into creating motor fuels from algae may not succeed for at least another 25 years because of technical hurdles, said Chairman and Chief Executive Officer Rex Tillerson. “What we’ve come to understand is the hurdle is pretty high and the hurdle seems to exist at the basic science level, which means it’s even more difficult to solve. These are very challenging problems.” So far, scientists haven’t been able to develop a strain of algae that reproduces quickly enough and behaves in a manner that would produce enough raw material to supply a refinery, Tillerson said March 7 on PBS television’s “Charlie Rose” show.
10 Oct 2007. Chris Somerville, Director, Energy Biosciences Institute, U.C. Berkeley “Technical issues associated with the development of lignocellulosic biofuels Colloquium”. I was present at this talk, and he practically gave my “Peak Soil” paper — he thought it would be at least 20 years of basic science research before any kind of useful fuel could be scaled up for the market. I think he was honest at this talk because only about 30 Energy Resources Group PhD and postdoc students attended this seminar.
Current algae research
• Labs are bioengineering and zapping algae with radiation and chemicals to come up with a prolific mutant strain, so far without any luck. Venter sampled algae all over the globe to look for a winning strain with no luck and has decided to make the magic algae himself from bits and pieces of genetic parts.
• Synthetic biology company Amyris’s chief technology officer, Neil Renninger says that we ware never going to replace petroleum with algae, at best we can hope to augment oil (as is done with ethanol now).
Sources (just a few, not all of them):
Biello, David. 2011 August. The False Promise of Biofuels The breakthroughs needed to replace oil with plant-based fuels are proving difficult to achieve. Scientific American.
Krassen Dimitrov, Ph.D. March 2007. GreenFuel Technologies: A Case Study for Industrial Photosynthetic Energy Capture. Brisbane, Australia.
Heading Out. 29 May 2009. Cost Viability and Algae. Theoildrum.com
Savage, Phillip. 23 Nov 2012. Algae under pressure and in hot water. Science, vol 338, p 1039
Sanseverino, Nicole. 7 Nov 2011. Professor explores algae as fuel source. The Daily Texan.

  • 3
  • 3

For at kunne vokse skal alger have adgang til kuldioxid. 1 m³ luft indeholder ca. 78 mg kuldioxid.
Prøv selv at regne på, hvor meget luft, der skal blæses gennem en algedam, før der kan komme vækst af betydning. Og prøv også at renge på, hvad det koster.

  • 1
  • 0

Inden man skyder projektet ned må man være ikke være blind for at teknisk udnyttelse af mikroorganismer, er Danmarks næststørste eksportsucces efter landbrugsproduktionen. Når man tæller alt med fra bage gær til medicinproduktion og enzymer. Og det er vel et spor der er værd at forfølge? Om det kan betale sig at fremstille simpel råolie udfra mikroorganismer ved jeg ikke men ligesåsnart der er tale om mere avancerede produkter er det åbentbart rentabelt at udnytte mikroorganismer til produktion.

Venlig hilsen Peter Vind Hansen

  • 2
  • 0
Bidrag med din viden – log ind og deltag i debatten