Scientists propose artificial trees to scrub CO2 out of the atmosphere - but the real thing could be smarter

Some scientists suggest the threat of climate change has become so great, that we must begin to consider 'geo-engineering' the planet to mitigate global warming. Several futuristic proposals are on the table, but many of these have been dismissed as too risky (previous post). Two broad categories can be distinguished: geo-engineering 'mirrors' that reflect sunlight back into space to cool the planet, and options based on capturing and storing CO2.

Amongst the first series the following ideas have been suggested: emulating the cooling effects of a large volcanic eruption by filling the atmosphere with sulphur particles (dismissal here), making clouds more reflective by pumping fine salty water particles into them, and building a giant space mirror by launching billions of thin glass plates into space to reflect sunlight away from Earth (which would be absurdly costly).

Carbon capture ideas include the proposal to 'fertilize' the oceans with iron to induce algae blooms that capture CO2 (critique here), and building 'synthetic trees' that suck CO2 out of the atmosphere with the gas consequently stored deep under ground (earlier post).

Artificial trees
The latter idea is now becoming a reality. Frank Zeman at Columbia University believes CO2 could be efficiently extracted from the atmosphere using a relatively simple chemical process involving pumping air from the atmosphere through a chamber containing sodium hydroxide, which reacts with the CO2 to form sodium carbonate. This carbon-containing solution is then mixed with lime to precipitate powdered calcium carbonate – a naturally occurring form of which is limestone. Finally, the 'limestone' is heated in a kiln releasing pure CO2 for storage.

The 'artificial tree' concept is discussed in an article in the current online edition of Environmental Science & Technology. Zeman calculates that one carbon atom would need to be expended as fuel – to pump air and heat the process – in order to capture four carbon atoms from air.

Zeman has no commercial plans for his idea, but Klaus Lackner, a former colleague at Columbia who originally developed the concept, has meanwhile set up a private company called Global Research Technologies to explore the possibilities of making money out of it.

Real trees and carbon-negative energy
According to Jon Gibbins, an expert on energy technology at Imperial College in the UK, Zeman and Lackner's idea faces two major problems: (1) it could provide a justification for continuing to burn fossil fuels, and (2) it does not present a clean energy system as it merely removes carbon dioxide from the atmosphere. There is however a concept that performs the same function as Zeman's idea but delivers renewable, ultra-clean carbon-negative energy at the same time, which allows us to move away from fossil fuels. This concept, known as 'Bio-energy with Carbon Storage' (BECS) is based on real trees designed to capture and store more carbon, and on advanced bioconversion concepts:
energy :: sustainability :: biomass :: bioenergy :: biofuels :: carbon dioxide :: carbon capture and storage :: bio-energy with carbon storage :: geo-engineering ::

Gibbins believes it makes more sense to use carbonaceous fuels to generate electricity, capture the CO2 at the power plant, and use the resulting electricity to power cars and trains.

Is it better to burn fossil fuels and capture the carbon dioxide from air, or to decarbonise the power first and put that into transport? If we bite bullet and move on to electricity then we can use electricity from anywhere, including renewable sources. - Jon Gibbins, Imperial College

If the fuels in question are renewable biomass - real trees - the electricity produced becomes carbon-negative. Such BECS systems perform the same function as Zeman's idea, but are more efficient and allow us to make a transition towards carbon-negative electricity for transport, away from fossil fuels.

Zeman claims that his process does not use any more energy than decarbonising emissions straight from power plants. But Gibbins points out that much of Zeman's process is run on electricity, while carbon capture at (biomass) power plants relies on waste heat, making the system potentially more efficient.

The BECS concept offers the possibility to couple biomass production and trade to a global transition to carbon-negative electricity. Unlike other renewables like wind or solar - which are carbon-neutral and merely prevent emissions from occuring in the future - BECS systems take emissions from the past out of the atmosphere and can take us back to lower CO2 levels far more quickly.

Scientists who developed BECS concepts within the context of 'Abrupt Climate Change' (ACC) scenarios, project that the systems can reduce atmospheric CO2 levels rapidly, safely and without the need for alternative and risky geo-engineering interventions. If implemented on a global scale, BECS can bring atmospheric CO2 back to pre-industrial levels by mid-century (earlier post and especially here).

The prospects for BECS systems are looking good. Recently the UNFCCC announced it would include carbon storage into the Clean Development Mechanism (CDM), but only in developing countries where more than 50% of all electricity is generated by coal. Many of these countries have a large potential to produce sustainable biomass close to geosequestration sites. Its inclusion into the CDM means the BECS concept will be eligible for carbon credits which would make it more feasible.

Moreover, recent advances in plant biology have seen scientists designing fast-growing trees with enhanced carbon capturing capacities. A hybrid larch tree with 30% greater carbon sink capacity was developed (previous post), as well as an eucalyptus with 15% increased carbon capturing capacity (more here). Such trees would be used as primary carbon capture 'machines', then transformed into bioenergy (bio-electricity or biofuels) and the carbon captured and geosequestered.

Finally, a major advantage of BECS is that it can be implemented in a decentralised way, increasing its safety (one of the major risks with geosequestration is the potential for CO2 leakage). Geosequestration sites can be selected far away from inhabited regions; there, biomass would be grown and converted into the carbon-negative biofuel, which would then be shipped to power stations there where electricity is needed. If the biomass is converted by using synthetic fuel production methods (gasification coupled to Fischer-Tropsch synthesis), the carbon-negative fuels later used in cities would be ultra-clean and emit virtually no harmfull emissions. Recently a project in this sense was started, initiating the transition to BECS. It is based on producing synthetic fuels from a mixture of coal and biomass, with CO2 emissions sequestered (earlier post). When the coal is left out, a full BECS-system emerges that results in ultra-clean, carbon-negative fuels that can be used for transport, or for the production of electricity.

Image: rendering of a synthetic tree used by the BBC in a documentary about geo-engineering options, which included a discussion of Lackner's idea. Credit: BBC.

References:
Frank Zeman, "Energy and Material Balance of CO2 Capture from Ambient Air", Environmental Science & Technology, ASAP Article, September 26, 2007, doi:10.1021/es070874m

Biopact: Capturing carbon with "synthetic trees" or with the real thing?- February 20, 2007

Biopact: A closer look at the revolutionary coal+biomass-to-liquids with carbon storage project - September 13, 2007

Biopact: Carbon-negative energy gets boost as UNFCCC includes CCS in CDM mechanism - September 19, 2007

Biopact: Japanese scientists develop hybrid larch trees with 30% greater carbon sink capacity - October 03, 2007

Biopact: Scientists develop low-lignin eucalyptus trees that store more CO2, provide more cellulose for biofuels - September 17, 2007

Biopact: Simulation shows geoengineering is very risky - June 05, 2007

Article continues

Study: tariff reductions in the Doha Round will erode border protection for EU agricultural products

Agriculture is at the centre of the multilateral round of trade negotiations under the World Trade Organization (WTO), the so-called 'Doha Round'. The Global South wants both the United States and the European Union to decrease farm subsidies and abandon tariffs for agricultural products. The developing countries stand united in the G-20, but are confronted with an ongoing dispute between the EU and the US, which holds back progress (earlier post). Market access compared to export competition and domestic support is the most difficult of the three pillars to negotiate. The US is aggressively demanding for significant reductions in tariffs, but the EU is unable to do so because further tariff reductions will erode border protection for some of its important agricultural products.

MTT Agrifood Research Finland has completed an interesting study [*.pdf] to reveal the sensitive agricultural products in the EU due to further tariff reductions in the projected Doha Round. The EU agricultural products are examined by tariff lines at eight digit level. These products are butter, skim milk powder, beef meat, poultry meat, pig meat, white sugar, wheat, barley, and maize. The sensitivity of EU agricultural products to the fluctuation of exchange rates from USD 0.90 per Euro to USD 1.50 per Euro is analysed in conjunction with the different tariff reduction formulas according to the EU proposal, WTO draft proposal, and US proposal for tariff-cuts.

Out of the many proposals submitted to the WTO for the tariff reduction formula, the US proposal is the most extreme and the EU proposal is the most lenient with the G-20 proposal and the WTO draft proposal being in the middle. Naturally, the projected results show that the EU proposal will generate a lower number of sensitive products compared to the WTO draft proposal, and the US proposal will generate the highest number of sensitive products:
energy :: sustainability :: biomass :: bioenergy :: biofuels :: agriculture :: trade :: tariffs :: subsidies :: Doha :: WTO ::

The results reveal that poultry meat has the lowest border protection among the examined EU agricultural products, followed by butter. Poultry meat is sensitive to the tariff reduction formula under the WTO draft proposal in almost all the exchange rate scenarios, except when the Euro is very weak (USD 0.90 per Euro). Likewise, butter is sensitive to the tariff reduction formula under the US proposal in almost all the exchange rate scenarios with the exception of a very weak Euro – USD 0.90 per Euro.

On the other hand, EU cereals such as wheat, barley, and maize are the most resilient to the erosion of border protection due to further reduction in tariffs in the projected Doha Round, followed by skim milk powder in the EU dairy sector. Border protection for cereals remains intact even after implementing the tariff reduction formulas from all the three proposals. In addition, border protection for cereals is not affected by a variety of exchange rate scenarios.

As the second most resilient product, skim milk powder is only sensitive to the tariff reduction formula under the US proposal and when the Euro is very strong – USD 1.50 per Euro. The results also demonstrate that EU agricultural products are very sensitive to the fluctuations of exchange rate. There are no sensitive agricultural products under any of the tariff reduction proposals if the Euro is very weak – USD 0.90 per Euro. On the contrary, a very strong Euro (USD 1.50 per Euro) will create the highest number of sensitive products in the projected Doha Round.

WTO members are entitled to select and designate an appropriate number of sensitive products. Proposals have extended from as little as one percent to as much as fifteen percent of tariff lines. The WTO draft proposal estimated that the number of sensitive products may be between four to eight percent of all agricultural tariff lines. Therefore, the EU may be eligible to designate between 88 to 176 tariff lines as sensitive products. This study has analysed only nine tariff lines out of the 2200 tariff lines for EU agricultural products. The examined EU agricultural products may represent other tariff lines in the same product category, but potential sensitive products at eight digit level have to be analysed individually in order to choose the correct and exact number of sensitive products for the EU.

References:
Ellen Huan-Niemi, "Market access under the World Trade Organisation: Identifying sensitive products in the EU" [*.pdf], MTT Working Papers 146, 23 pages - October 2007

Biopact: Latest Doha talks collapse again, agriculture remains stumbling block - June 21, 2007

Article continues

Thermoelectric devices could save energy by tapping waste heat

Energy lost from hot engines and combustion systems could save billions of dollars if it could be captured and converted into electricity via thermoelectric devices, Clemson University physicist Terry Tritt told scientists gathered in Dallas for the NanoTX ’07 conference. Tritt delivered an address at the Alan MacDairmid Memorial Nano Energy Summit on challenges in alternative energy, specifically thermoelectricity used to generate electrical energy from waste heat.

Thermoelectric generators are based on materials that are special types of semiconductors. When coupled, they function as a heat pump: a temperature gradient is applied across a sample, electrons diffuse from the hot to the cold part due to the larger thermal speed of the electrons in the hot region, a charge difference then builds up between the hot and cold region, creating a voltage and producing an electric current (schematic, click to enlarge).

Thermoelectric materials can be used for either cooling or power generation. Although current devices have a low conversion efficiency of around 10 per cent, they are strongly advantageous as compared to conventional energy technologies. The converters have no moving parts and are therefore both reliable and durable.

Such waste heat recovery technologies could increase the efficiency of small bioenergy power systems and even of ordinary biomass cooking stoves (an example of research in this context). Large biomass power systems allow for polygeneration and the use of heat in distributed (district) heating and cooling systems. But small biomass power systems generate equally large amounts of waste heat that can not always be used in such a straightforward way. Thermoelectric generators could recover this waste heat and convert it into more electricity.

Many more applications can be envisioned. One of the more interesting ones involves capturing waste heat from cars' internal combustion engines.

Thermoelectric generators are currently used in NASA’s deep-space probes to convert the heat of radioactive elements to electrical energy, powering these systems for over 30 years. Thermoelectric energy conversion is a solid-state technology that is environmentally friendly. One of the more promising ‘down-to-earth’ applications lies in waste-heat recovery in cars. - Terry Tritt, Clemson University

More than 60 percent of the energy that goes into an automotive combustion cycle is lost, primarily to waste heat through the exhaust or radiator system. Even at the current efficiencies of thermoelectric devices, 7 to 8 percent, more than 1.5 billion gallons of diesel could be saved each year in the U.S. if thermoelectric generators were used on the exhaust of heavy trucks. That translates into billions of dollars saved:
energy :: sustainability :: biomass :: bioenergy :: biofuels :: combustion :: heat recovery :: thermoelectricity :: nanotechnology ::

Clemson research focuses on developing higher-efficiency thermoelectric materials that could increase savings significantly. Research on the electrical and thermal properties of new materials could reduce the world’s reliance on fossil fuels and has shown promise with two classes of materials: low-dimensional systems for enhanced electrical properties and increased phonon scattering that leads to inherently low thermal conductivity.

Tritt heads up the Department of Energy’s Center of Excellence in Thermoelectric Materials Research at Clemson, one of the leading laboratories for thermoelectric materials in the world. The national center focuses on the next generation of thermoelectric materials for power conversion and refrigeration. Researchers in physics, materials science and chemistry screen promising new classes of materials in order to achieve higher-performance thermoelectric materials. DOE recently renewed the program with more than $1 million a year in research funding for the next three years.

NanoTX, presented by Semiconductor Industry Association, highlights advances in nanoscience and explains how nanotechnology is being used today and how it will impact a broad range of industries tomorrow, including electronics, energy, aerospace, defense, biomedicine, robotics, chemicals and more.

References:
Clemson University: Clemson physicist addresses international forum on thermoelectric energy - October 4, 2007.

Thermoelectric News: US DoE awards $3 Million to Clemson - September 29, 2004.

NanoTx '07 conference & expo.

An older but good introduction to the topic of thermoelectric material science can be found in: Terry M. Tritt, "Thermoelectric materials: Holey and Unholey Semiconductors", Science 5 February 1999: Vol. 283. no. 5403, pp. 804 - 805, DOI: 10.1126/science.283.5403.804

C. Lertsatitthanakorn, "Electrical performance analysis and economic evaluation of combined biomass cook stove thermoelectric (BITE) generator", Bioresource Technology, Volume 98, Issue 8, May 2007, Pages 1670-1674, doi:10.1016/j.biortech.2006.05.048

Article continues

MyFuel to build two large palm oil biodiesel plants in Malaysia

Malaysia-based MyFuel Ltd plans to invest some 160 million ringgit (€33.2/US$46.9 million) to set up two biodiesel facilities at the Port Klang Free Zone, one of the main ports of Malaysia, located south of Kuala Lumpur. MyFuel has been granted the license to set up the biodiesel plants and expects them to be completed in June of next year.

The palm oil-based methyl ester plants, to be built on a 3.2 hectare factory site on a 30-year lease, will have an output of 100,000 and 250,000 metric tonnes a year. Group managing director George Joukado told Malaysia's state news agency Bernama the plants will be equipped with process equipment from European supplier Desmet Ballestra.

At full production the plants will create annual turnover and spin-offs estimated to exceed 1 billion ringgit (€208/US$293 million).

The extraordinarily high palm oil prices, choppy international biodiesel market conditions and the rise in fossil fuel prices certainly pose a challenge. However, they will not unduly upset the long-term prospects and viability of biodiesel. - George Joukador, managing director MyFuel

According to Joukador, the company has signed supply arrangements with reputable palm oil suppliers and has signed agreements with third parties for marketing and sales to ensure the reliable supply of feed stocks and pre-marketing of end-products:
energy :: sustainability :: biomass :: bioenergy :: biofuels :: biodiesel :: palm oil :: Malaysia ::

It has inked a marketing and distribution agreement with biodiesel brand leader World Energy Alternatives (WEA) under which all WEA purchases of biodiesel from Asia Pacific will be supplied by MyFuel.

MyFuel has two subsidiaries for the Malaysian operation - Biodiesel SP Sdn Bhd and Biodiesel LD Sdn Bhd.

Surging feedstock prices have prompted Malaysia, the world's leading palm oil producer, to put on hold the implementation of a biofuel act aimed at facilitating the commercialization of Malaysian-made palm oil-based biodiesel. However, prices are expected to decrease as new production comes online.

References:
Bernama: MyFuel To Invest RM160 Mln In Biodiesel Facilities - October 3, 2007.

Article continues

IISD report challenges EU biofuel subsidies, calls for end to tariff

A new report gives yet another boost to the idea of a Biopact, which consists of wealthy countries in the North importing efficient and sustainable bioenergy and biofuels made in the South, as a way of creating a new trade relationship in which development, poverty alleviation and energy security take center stage. In order for such a pact to succeed, trade reform is needed and subsidy schemes in the EU and the US must be changed.

The European Union's support for biofuels may not be the most cost-effective way for the 27-country bloc to tackle climate change, the new study concludes. Its lead author argues that the EU better import sustainable biofuels made in poor countries like Brazil, because they are highly energy efficient, reduce greenhouse gas emissions far more and are highly competitive compared to biofuels made in the EU. The same researchers, working for the Global Subsidies Initiative (GSI), earlier analysed biofuel subsidies and their trade distorting effects in the US and came to similar conclusions (previous post).

Last year EU governments spent at least €3.7 billion ($5.2 billion) on subsidising biofuel production. Such support is likely to grow in the coming years because the Union has set a strategy of raising the quantity of road fuel generated from biofuels from its present level of 2 percent to 10 percent by 2010.

But the International Institute for Sustainable Development (IISD) in Geneva has queried if allocating large amounts of public funds to EU biofuels is desirable. In a study titled Biofuels At What Cost? Government Support for Ethanol and Biodiesel in the European Union [*.pdf] it calculates that the cost of using ethanol from sugar beet to avoid emitting one tonne of carbon dioxide (CO2) - the main gas blamed for climate change - ranges from slightly less than €600 to €800 ($760 to $1,000).

Producing biofuels from crops grown in the EU is generally an energy-intensive business, which in itself makes use of considerable quantities of fossil fuels. As a result, the study says, the overall saving of fossil fuels brought by biofuels may be low, and introducing carbon or pollution taxes may prove more effective.

Generally, biofuels made from high-sugar crops such as sugar cane or high yielding oil crops like palm oil can contribute to higher savings on fossil fuels than those made from oilseeds or grains. More than 90 percent of the 6 million tonnes of biofuels produced in the EU during 2006 was made from rapeseed oil.

Ron Steeblik from the GSI urged the Union to eliminate tariffs on imported ethanol, a fuel made from sugar. Ethanol with an alcohol content of 80 percent is subject to a tariff of 19.20 euros (27 dollars) per 100 litres. 'Denatured' alcohol, which has a lower content, is taxed at just over half that level.

These taxes are inimical to poor countries like Brazil. This is contrary to the EU's general policy of trying to reduce tariffs. It is far higher than any tariff on industrial goods and is an old-fashioned instrument for protecting agriculture.

Import tariffs on ethanol from Brazil, one of the most efficient producers of biofuels, reduce the amount of sales that can be made by a developing country. The EU's policy is incoherent. If biofuels are so good, why is it taxing them so heavily at the border? - Ron Steenblik, lead author, Global Subsidies Initiative

The EU executive, the European Commission, is expected to propose a new law setting down the criteria for supporting biofuels by the end of this year:
energy :: sustainability :: ethanol :: biodiesel :: biomass :: bioenergy :: biofuels :: subsidies :: trade :: tariff :: EU ::

Officials are examining how to prevent support for biofuels in cases where their production involves the emission of more greenhouse gases than would eventually be saved by using them instead of pure fossil fuels.

However, there are some who support biofuel subsidies. Lena Ek, a Swedish Liberal member of the European Parliament (MEP), said that "biofuels will be there as part of the solution" to global warming. She asked, therefore, if subsidising them is "really a bad thing."

Ethanol has proven economically beneficial to Brazil, she added. "Brazil has got out of the fossil economy," she noted. "Last year it paid off the debt it owed to the World Bank."

Swedish conservative MEP Anders Wijkman said: "We need subsidies if we want new energy in the market place. But the question is how do we lock ourselves into a production scheme that is really feasible. The logical question is how to ensure the end result really eliminates carbon dioxide."

A European Commission official said that there is a "serious misunderstanding" about the factors motivating biofuels policy in the Union. One widely held view, he said, is that the principal objective is to support the income of crop farmers. "It has nothing to do with that," the official said.

The real issue for the Union, according to the official, is having a "policy in place" to meet an increased demand for biofuels.

But Ron Steeblik said that high subsidies for biofuels "could potentially create a lot of instability for other markets, including the agriculture market."

His colleague at the Global Subsidies Initiative David Runnalls said that the EU should beware of aping the support system for biofuels in the U.S. He argued that it is preferable to support research into biofuels, as has been done in Canada, than to link support for them to the level of production, the method favoured in Washington.

In some parts of America, he said, subsidies account for 2.40 dollars of the price of a three-dollar gallon of biodiesel.

"There is a potentially distorting effect of biofuels wrongly applied in the wrong place and the wrong time," said Runnalls. "We are not opposed to subsidies. What we are opposed to is governments spending them in an ill-advised fashion."

References:
IISD: International Institute for Sustainable Development's Global Subsidies Initiative releases Biofuels – At What Cost? Government support for ethanol and biodiesel in selected OECD countries - October 3, 2007.

Global Subsidies Initiative: Biofuels At What Cost? Government Support for Ethanol and Biodiesel in the European Union [*.pdf] - October 3, 2007?

Biopact: Subsidies for uncompetitive U.S. biofuels cost taxpayers billions - report - October 26, 2006

Article continues