As part of an algae special in issue 160 (June 2011), Ian Wellby wrote a triple article; Algae - Understanding, Treating and Preventing.
This article, Algae; the future, provided the end-piece. It explored whether algae has any benefits and what it may have in store for us for the future.
Algae; The Future
Every koi keeper is familiar with algae as a creeping menace, but does the green stuff have any merits?
Road transport is vital to koi-keepers. It isnít possible for us to go completely green and totally dispense with our cars. Cycling to a dealer isnít an option when collecting fish or complete filter systems. Whether they are collected in our own cars or delivered by the dealer, fish or bulky goods will always have to be carried by road vehicles.
Electric vehicles and increased use of railways are being proposed as a solution to carbon emissions from road transport but a typical electric delivery van has a maximum range of 60 miles under ideal conditions, and this reduces when carrying a load. Its top speed is 30 m.p.h. and it needs nine hours for a full recharge. There are currently no prospects for heavy lorries that would allow a buildersí merchant to deliver the tons of blocks and other materials to build your next pond. So the internal combustion engine will be needed for the foreseeable future.
Current bio-fuels conflict with food production
Until recently, scientific research has been directed towards replacing imported oil with an ecologically sustainable fuel, called bio-diesel, derived from growing crops such as soya beans or rapeseed. These crops contain lipids (fatty molecules) which can literally be squeezed out of the plants by means of a high power press to produce vegetable oils. Adding a centrifuge makes the process more efficient. Simple chemical treatment with ethanol turns this oil into bio-diesel which is almost the same as normal diesel oil.
However, this isnít as ecologically friendly as it may seem. Every acre used to grow a crop for bio-diesel is one less acre available for food crops and this is affecting food prices in some of the poorer areas of the World. One acre of prime agricultural land only produces 48 gallons of soybean oil per year. Rapeseed is better at 127 gallons per acre, but these low yields per acre are making bio-fuels produced from these crops too expensive to compete with fuels produced from oil.
Future algae fuel will change that
This is where obtaining bio-fuel from algae can help. It doesnít need to grow on prime agricultural land so it doesnít take land away from food cultivation. An algae pond built on one acre of non-agricultural land can produce up to 15,000 gallons of bio-fuel per year because some strains of algae contain 60% lipids and reproduce so quickly that they can be harvested on a weekly basis.
If algae fuel replaced all the petroleum fuel in the United States, it would require about 15,000 square miles of land to do so. This would only mean finding an additional area equal to 14% of that already being used for farming, and since the land will only be needed for algae ponds, it could be the poorest quality land that has no other possible use.
In addition to being the most suitable algae for producing bio-fuel, pond scum algae (scenedesmus dimorphus) is also invaluable to the environment in general. It thrives in conditions where most other aquatic plants cannot. It is able to live in near-stagnant water, where it uses up contaminants and provides oxygen into its aquatic environment. It often, single-handedly, is responsible for putting sufficient oxygen into otherwise poorly oxygenated ponds that they are prevented from becoming anaerobic which would cause the deaths of most aquatic creatures in them. In addition to this, it is also food for daphnia, rotifers and similar small creatures which, in turn are food for higher lifeforms such as fish.
When commercially produced fuel from algae is widely available it will be the ultimate in renewable energy. It doesnít affect the level of carbon dioxide in the atmosphere. As algae grow they remove CO2 from the atmosphere then, when the fuel is burned, the exact same amount of CO2 is released back into the air. No more, no less. We could visit koi dealers in our cars with impunity because the amount of CO2 we released into the atmosphere on the journey would be exactly balanced by the amount of CO2 used by the algae in making our next tankful. When algae oil fuel is fully available we could drive cars that effectively have a zero carbon footprint!
Producing bio-fuel from algae is easy. The diagram shows a simplified schematic of how this is done. The nutrients could literally be any waste water, even sewage. With the cost of research factored in, bio-diesel is more expensive to produce than diesel refined from oil, but with oil prices rising, the gap is closing and some researchers expect that by around 2017, petro-chemical companies may find farming oil is becoming competitive with the costs of drilling for it.
Could we make our own?
Yes, all that is needed is a culture of a suitable algae and a bio-reactor in which it can grow. Unfortunately, although blanket weed could be used to make bio-fuel, the yield would be low because blanket weed has a low lipid content. But with the right strain of algae, anyone can make bio-diesel using simple equipment that could lay fairly flat on a pergola roof over a pond, or with equipment the size and shape of a large vortex that could stand upright in a sunny corner of the garden. Designs for equipment to produce fuel from algae are just appearing on the Internet with claims that the fuel can be used in standard unmodified engines.
Some manufacturers allow their engines to operate on 100% bio-diesel without voiding the warrantee Ė others allow their engines to be fuelled by bio-diesel but impose strict limits to the percentage that can be added. Current designs for home-made equipment couldnít make enough bio-diesel to run an average car for the entire year anyway. However, with small oil boilers, which will also run on bio-fuels, selling at less than £600, they are becoming competitive with gas boilers, and with fossil fuel prices rising, it may soon be economically viable to produce bio-fuel oil to store in a small underground tank to heat the pond throughout the winter. Koi keepers may have to stop hating algae and actually learn to love it.
Ten things you didnít know about algae
- There are about 7,000 species of green algae which can be found in fresh water, salt water and also in damp places. Nearly all sea-weeds are actually salt water species of algae.
- With bio-fuel from algae, oil-spill accidents will become a thing of the past. Algae bio-fuel is totally and rapidly bio-degradable, in fact if there is an accidental spill, it will fertilise the ground on which it is spilt.
- Some strains of algae in day-long bright sunshine reproduce so quickly that they can be harvested for bio-fuel on a daily basis.
- Research is indicating that algae bio-fuels are such good solvents that they actually clean the engine as they are being used which will prolong the life of the engine.
- Many species of green algae are motile, meaning that they have whip-like tails that propel them through water in response to lighting conditions.
- It is usually thought that all algae reproduce asexually by cell division of a single parent, but some reproduce sexually by two separate alga combining together and exchanging genetic material before separating. The receiving alga then divides into two separate cells.
- The oldest known fossil is of a single-celled organism, a blue-green algae, found in 3.2 billion year-old rocks in South Africa.
- Corals have algae living inside them. The algae make sugars by photosynthesis which it shares with its host in return for the protection it has from living inside it.
- Algae produce about 80% of the oxygen in the atmosphere.
- The first organisms to evolve on the Planet were anaerobic, oxygen was poisonous to them. When algae developed, they produced so much of their waste product, oxygen, that it poisoned most other life-forms causing them to become extinct. Algae were the first producers of toxic waste.