The Good Oil

As New Zealand scrambles to do its bit to cool the globe and give green­house gas the boot, there is a groundswell of enthusiasm for sustainable technologies ranging from the elegantly simple to the intriguingly complex. Organisations as varied as schools and state-owned enterprises, pulp mills and universities are working on technologies to save us from ourselves.

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At the sharp end are ideas that make your fingertips tingle with excitement, like plans for a pyrolysis plant that burns wood in a controlled atmosphere to produce carbon monoxide, hydrogen, bio-oil and bio-char for digging into agricultural land to mimic the fertile black soils of the Amazon basin. Another is to harness the moon’s gravity by anchoring underwater turbines in Cook Strait to generate electricity from the tides.

Then there is the quieter revolution. Schools from Naseby to Rotorua have converted classroom heating from coal to sustainable wood, using wood chips, or pellets made out of sawdust from nearby sawmills, for burning in high-tech, low smoke and ash furnaces.

Industry is pulling its weight too. Winstone Pulp Inter­national’s mill at Karioi has installed a 12MW bark furnace and a heat exchanger to recover 3MW of heat from steam for drying pulp, drastically reducing electricity and LPG use. Excess heat is used to dry timber from the nearby Tangiwai sawmill. Genesis Energy has reduced its carbon dioxide emissions from Huntly Power Station by a million tonnes a year, and dairy companies are making biofuel from whey.

Many who seek funds to prove their smart new tech­nologies are reluctant to divulge details, rightly fearing competitors will learn their secrets. Others don’t want to be told their brainchild is stillborn because it defies the laws of the universe or consumes more electricity and energy than it produces. For all the genuinely innovative ideas on how to save the planet there are as many charlatans, peddling projects that range from the equivalent of the perpetual mo­tion machine to concepts so novel they make your eyes water with disbelief. In the rush to grab the next smart technology it’s also easy to forget the tried and tested, such as burning sustainable wood and generating hydro electricity.

Now that you have been warned, let’s have a look at a handful of clever ideas to deal with greenhouse gases and global warming.

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If only all that carbon dioxide warming the atmos­phere could be separated into its constituent oxygen and car­bon atoms, it wouldn’t be such a threat. Unfortunately carbon dioxide is so stable it’s almost inert, with a molecular bond so powerful that to break it would bust the energy bank.

Nature deals with the stuff naturally through photo­synthesis in plants and algae, which is then sequestered underground in oil and coal deposits. However, nature can’t keep up with humanity’s current emission excesses, hence the urgent international call to change our ways.

If we closed down the coal-and-gas fired Huntly Power Station, it would immediately save us some 539,000 tonnes of carbon dioxide emissions a month. But there’s another way; capturing gases before they do any harm.

In a small outbuilding at Industrial Research Ltd in Lower Hutt, Robert Holt is doing just that. He’s testing a novel technique that will concentrate and remove carbon dioxide from the flue gases of coal-fired power stations and steel foundries. The carbon dioxide could then be used for industrial purposes or artificially sequestered underground.

Industrial Research’s invention is on a scale that could fit on a laboratory bench and Holt predicts an industrial scale plant will only occupy a tenth of the space of existing (amine-based) carbon dioxide capture systems. Plant cost is proportional to size, and so size does matter.

Coal is New Zealand’s most abundant fossil fuel, and most of it goes up in smoke at Huntly Power Station. It’s a mixed blessing in energy terms—there’s enough of it to power the nation for centuries, but coal is also the most carbon-rich of the fossil fuels and for every tonne burned, it produces two tonnes of carbon dioxide.
Coal is New Zealand’s most abundant fossil fuel, and most of it goes up in smoke at Huntly Power Station. It’s a mixed blessing in energy terms—there’s enough of it to power the nation for centuries, but coal is also the most carbon-rich of the fossil fuels and for every tonne burned, it produces two tonnes of carbon dioxide.

New Zealand’s carbon dioxide emissions are small in glo­bal terms, especially as much of our electricity is generated from renewable resources. “But with China commissioning two coal-fired power stations a week, this technology could have a significant impact on world greenhouse gas emissions,” says Holt.

Another outfit sniffing flue gases to save the world is Lan­zaTech of Auckland, which claims it can turn poisonous pollution into biofuel—more specifically, it can convert carbon monoxide into ethanol.

Ethanol is the same ethyl alcohol we imbibe in our whis­ky, wine and beer, and is produced by fermenting sugars. It’s being touted as a replacement biofuel for petrol and can be manufactured industrially; LanzaTech is using microbes, and claims its know-how could produce 200 billion litres of ethanol annually from the world’s steel mills alone.

“We have proven in our laboratories that the carbon monoxide in industrial waste gases can be processed by bac­terial fermentation to produce ethanol,” says Sean Simpson, LanzaTech’s founder and chief scientist. He envisages a Lan­zaTech plant that would look much like brewery adjacent to a steel mill and agrees that the idea might sound like science fiction at present, but hopes the fuel will go to market in the next five years. Indeed his work is being taken seriously enough to attract massive investment from both government and private investors.

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Over millennia, algae has produced the vast hy­drocarbon reservoirs that fuel our modern civilization. But as the levels of carbon dioxide absorbed by our oceans and waterways spiral ever higher, the algae can rapidly multiply into a smothering toxic bloom. Ironically, it is the algae itself that may be the key to a sustainable transport fuel that will curb our emissions, save the world and end the algal plan for global domination.

Sunlight on micro-algae produces biomass at an astound­ing rate, and a patented contraption at the Christchurch Bromley Sewage Farm has been converting it into hydro­carbons ranging from gas to bitumen since 2003. The man behind the plant is solvent recovery expert, Chris Bathurst, who talks of replicating nature by heating algae in a pressure cooker. This cracks the long chain oil molecule into lighter hydrocarbons which separate naturally from the water. Other energy-hungry methods being promoted—but with little chance of success—include fermentation and transesterification. Bathurst was reluctant to give away too many details of his technology, but confirmed that sludge made up of 30 per cent algae and 70 per cent water is processed continuously at 2.5 litres a minute.

“You can dissolve any organic matter in water so long as the temperature and pressure are high enough,” he says. The concept could also have intriguing implications for convert­ing wood products into liquid fuels.

According to consulting engineer, David Painter, a hec­tare of pond-grown micro-algae will produce 30,000 litres of oil a year, which is considerably more efficient than the typi­cally quoted yields of 1200 litres from a hectare of rapeseed and 4000–4,500 litres from a hectare of sugar cane.

Professor Yusuf Chisti of Massey University’s School of Engineering in Palmerston North, who is also researching the potential of micro-algae as a source of transport fuel, agrees: “The oil content of some micro-algae is more than 80 per cent of the dry weight of algae biomass, compared with less than five per cent oil in crops such as soybean and oil palm.

“Bio-diesel from micro-algae seems to be the only renew­able biofuel that has the potential to completely displace petroleum-derived transport fuels without adversely affect­ing the supply of food and other crop products.”

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The New Zealand government goal to be one of the world’s first carbon-neutral economies led to the establish­ment of the Biofuels Sales Obligation. It is aimed at replac­ing 3.4 per cent of transport fuels with biofuels (by energy content) by 2012.

This could result in a happy spin-off for baby boomers who sank their savings into plantation forestry—New Zea­land currently has 1.8 million hectares of it—as they now own an energy resource that is catching the eye of research­ers trying to find ways to meet those obligations.

The Lignocellulosic Bioethanol Initiative has begun looking at using pine as a feedstock for bioethanol produc­tion. The initiative is a collaboration between New Zealand government research organisations, Scion and AgResearch, along with pulp and paper company Carter Holt Harvey, and US bioethanol and enzyme producer, Verenium Corporation.

Henry Ford designed his Model-T car to run on ethanol, which he described as “the fuel of the future”. It still might be. Sugars in wood pulp can be fermented with yeasts to produce ethanol, and because trees fix carbon dioxide in their wood as they grow, ethanol is prized as an environmentally friendly alternative fuel.
Henry Ford designed his Model-T car to run on ethanol, which he described as “the fuel of the future”. It still might be. Sugars in wood pulp can be fermented with yeasts to produce ethanol, and because trees fix carbon dioxide in their wood as they grow, ethanol is prized as an environmentally friendly alternative fuel.

The initiative has established that enzymes could be used to release sugars from pre-treated pine which, when fermented with yeasts or bacteria, would form ethanol. The soup would then be distilled to yield 100 per cent biofuel for blending with existing fossil fuels.

The initiative also established that a North Island pulp mill could ferment 730,000 tonnes of wood residues avail­able in its vicinity, to produce 98 million litres of ethanol a year, at a yield of about 270 litres from a tonne of bone dry wood. The cost per litre would be between $1.30 and $1.50 compared with imported Brazilian bio-ethanol (linked with rainforest destruction to plant palm oil crops) at between 80c and $1 a litre.

In 2007 New Zealanders consumed a whopping 3.3 billion litres of petrol and 2.9 billion litres of diesel. And although Scion claim that New Zealand could be self-sustaining in terms of fuel production from sustainably managed forests by as early as 2050, it depends on as-yet unproven technol­ogy and our willingness and ability to pay for it.

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Nine years ago, Tom McNicholl began converting used cooking oil into bio-diesel, but with only 5000 tonnes available annually he soon ran out of raw material. He then turned to tallow, a by-product of the meat industry, most of which is exported for use in the manufacture of soap and cosmetics.

McNicholl is managing director of BioDiesel-Oils NZ Ltd, which has developed a continuous transesterification process capable of converting tallow into bio-diesel—a kilo­gram of tallow yields 1.1 litres of bio-diesel. This was the fuel that powered Pete Bethune’s Earthrace boat from New Zealand to Hawaii on its record-breaking circumnavigation of the globe.

The company is building a plant at Waharoa in Waikato which will be able to process 60,000 tonnes of tallow each year, sourced from nearby freezing works. A similar plant is planned for the South Island. The bio-diesel is sold to oil companies for blending with regular diesel, and engines don’t require any modification to be able to run on the blend. The company hopes their bio-diesel will help meet the government target of 3.4 per cent biofuels by 2012.

Rapeseed is one of the preferred oil stocks for biodiesel crops, producing more oil per unit of land area than other oil sources, such as soy.
Rapeseed is one of the preferred oil stocks for biodiesel crops, producing more oil per unit of land area than other oil sources, such as soy.

Meanwhile, Biodiesel NZ Ltd, a subsidiary of Solid Ener­gy, continues to use cooking oil, collected from restaurants and food processors, selling their bio-diesel to fishing boats in Lyttleton Harbour. Most of their 14 staff are employed collecting the oil nationwide, in competition with a growing band of alternative lifestylers who filter it for use directly in their diesel cars.

Biodiesel NZ also employ two agronomists to encour­age crop farmers to grow rapeseed for the company yielding up to 1200 litres per hectare a year. General manager, Paul Quinn, a former motor mechanic stresses that rapeseed will not replace existing crops, as it is grown between harvests.

Parliamentary delays in passing the Biofuels Bill, which would require oil companies to sell minimum levels of biofuels, have cast some doubt on the viability of the industry. Investors are also wary because oil companies could import biofuel instead of using local juice.

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