Byogy Renewables announced recently that they are looking at setting up a $10 million test site to convert ethanol to gasoline. In Australia this could be from sugar cane or biomass from the grain industry and the site is likely to be in SA or Qld. They have connections to Sundrop Farms in Port Augusta and are a research group, trying to commercialise renewable processes.

Byogy have a process that converts ethanol (or any alcohol) to gasoline ( or as we would call it – petrol) and jet fuel. They see themselves as providing a better market for biofuels by having them ready to use in existing engines, including aircraft. This bypasses the need to add ethanol to current fuels.

The process involves catalytic conversion of the ethanol into long chain hydrocarbons and then distilling them to the required specifications. It does not require the manufacture and use of hydrogen, creating a simpler and cheaper process.

Biofuels have plenty of potential but have significant environmental and land use issues. Palm Oil and Sugarcane have some of the best conversion rates (in litres per hectare terms), but can only be grown in tropical areas, with the subsequent loss of tropical rainforests. Are there any better alternatives?

It is not a simple answer. Litres of product per hectare is one determinant but then biodiesel oils provide about 90% of the energy from gasoline while ethanol production only provide about 67% (although this depends on the engine).  Each crop also has a different cost to produce (in terms of economics, environment, energy input and GHG). There is also the social argument between growing crops for food or fuel.

Sugar cane produces about 7000 litres of ethanol per hectare and palm oil trees produce about 5500 litres biodiesel. These are the two highest producers and are about equivalent in energy terms. Other tropical trees can also produce similar amounts of fuel, including the diesel tree and Chinese tallow.

The Indian tree, Millettia pinnata in comparison can produce about 10000 litres biodiesel and algae can produce about 95000! The algae production requires an open lakes system.

Corn produces about 3000 litres ethanol per hectare and wheat and barley are similar. Various oil crops produce about 1000 litres (rapeseed, canola etc). Hemp, flax and cotton produce about 500. These last three have additional benefits as they can be also used to produce many fibrous products (fabrics etc).

Researching these figures show they are pretty rubbery with various factors affecting crop yields and production on an annual basis. It also depends on whether the product is first used for food and whether production is from waste after food production.

Hemp

Hemp is touted by many as a potential game changer. The stuff grown commercially is very different to cannabis but gets tied up in legal limbo as the two are treated similarly. They are both Cannabis Sativa but hemp has little THC.

Hemp has been used for fibre and the seeds used to make oil for centuries. During the 1930s and 40s there was increasing pressure to make cannabis (and hence hemp) illegal, at the same time as petroleum products were beginning to dominate. Du Pont is often blamed for forcing the prohibition so that its petroleum based products could succeed (eg nylon). There is some substance to this argument but it probably largely falls under the conspiracy theories banner.

The fact that hemp is associated with both cannabis and alcohol (for fuel) has, however inhibited its use over the last century. It now has many supporters and laws are gradually changing.  In Australia it is legal to grow it in a number of States.

Hemp grows well in a many soils and climates, requiring little tilling or fertilisers. It also has many uses. The seeds can be made into biodiesel and the stalks can be fermented to ethanol (or methanol).  It is a good replacement for cotton (supposedly more productive with less environmental damage) and is a good contender for bioplastics and fibreglass.  It is a potential alternative to trees for paper manufacture (including tissues). It is also a good source of protein.

Henry Ford apparently was a fan, suggesting that it could be used to make a form of bio fibre glass using hemp as the fibre. He made a demo car using about ten percent hemp to show how it could be done before the second World War.

It would appear to be a no brainer to grow and use more hemp. The economics of biodiesel from hemp are currently poor. Canola produces more oil per hectare.  But the beauty of hemp is the ability to use the whole plant, and it has the potential to replace many petroleum products.

Oil Trees

The big one is palm oil, grown mostly in Indonesia and Malaysia. Palm oil is now used in many products. It is regularly stated that half the products on supermarket shelves contain palm oil. It is edible, used in shampoos and cleaning products. On the other hand it is responsible for the destruction of large areas of tropical rainforest and therefore creates more greenhouse gas than it saves ( at least in the short term.

Tropical oil trees are already using the maximum land that we would seriously want cleared so increasing their use by any large amount is not a good solution. Other tropical trees may also produce more usable oil eg the diesel tree or Copaifera langsdorffii ) So what about temperate crops?

Millettia Pinnata is a member of the pea family and is grown widely in SE Asia. It is also known as the Pongam Oil Tree.  It grows in sub tropical and arid climates, is a nitrogen fixer and can grow in salty water.  In India many millions of trees have been grown in rural areas to provide fuel for the locals.  It is a great way to bring them out of total poverty.

Research has been progressing in Australia on using it as a biofuel crop. The tree is indigenous to Australia and was once widely used as a fish poison. The tree grows naturally in far north Queensland and if trees can be developed in more arid lands it could be a viable fuel crop.

Algae

Algal blooms all over the world show the ease of growing algae under the right conditions. Half the weight of the bloom is lipid oil, making this a great fuel source.  All you need to grow algae is the right temperature, sunlight, water and carbon dioxide.  Producing commercial quantities in an environmentally friendly fashion is the issue.  If we can, it will produce the most energy per hectare for biofuel production.

Bionic Leaf

Last year, a team from Harvard University invented the first “artificial photosynthesis device” that created alcohol directly from sunlight and air. It used a catalyst that helped split water molecules into its hydrogen and oxygen components and then a microbe to combine the hydrogen and CO2 from the air to produce alcohol fuels.  The problem was that the catalyst poisoned the microbes.

Last month the same group created a new catalyst (based on Cobalt and Phosphorus) which did not poison the microbes and had no known pollution effects. Currently it produces expensive fuel and requires substantial mining costs (although unlike batteries it does not require regular replacement).

Personally, I think this sort of technology is the way to go, hopefully using benign materials. It is possibly simpler to develop a hydrogen producing plant and then use the hydrogen directly for most energy needs.

In summary, much more research is required to find the best, most efficient (particularly for land use), environmentally friendly crops we can. Can we replace petroleum products completely?  Time will tell.

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