Global Carbon Budget: atmospheric CO2 level increasing more rapidly than anticipated

The Global Carbon Project (GCP) has released the Global Carbon Budget for the year 2007. These most recent figures are a key to understanding the balance of carbon added to the atmosphere, the underpinning of human induced climate change. Despite the increasing international sense of urgency, the growth rate of emissions continued to speed up, bringing the atmospheric CO2 concentration to 383 parts per million (ppm) in 2007.

This new update of the carbon budget shows the acceleration of both CO2 emissions and atmospheric accumulation are unprecedented and most astonishing during a decade of intense international developments to address climate change. - Dr. Pep Canadell, executive director of the Global Carbon Project

Annual mean growth rate of atmospheric CO2 was 2.2 ppm per year in 2007 (up from 1.8 ppm in 2006), and above the 2.0 ppm average for the period 2000-2007 (figure 1, click to enlarge). The average annual mean growth rate for the previous 20 years was about 1.5 ppm per year. This increase brought the atmospheric CO2 concentration to 383 ppm in 2007, 37% above the concentration at the start of the industrial revolution (about 280 ppm in 1750). The present concentration is the highest during the last 650,000 years and probably during the last 20 million years. [ppm = parts per million]. Anthropogenic CO2 emissions have thus been growing about four times faster since 2000 than during the previous decade, despite efforts to curb emissions in a number of Kyoto Protocol signatory countries.

Emissions from fossil fuels and cement increased from 6.2 PgC per year in 1990 to 8.5 PgC in 2007, a 38% increase from the Kyoto reference year 1990. The growth rate of emissions was 3.5% per year for the period of 2000-2007, an almost four fold increase from 0.9% per year in 1990-1999. The actual emissions growth rate for 2000-2007 exceeded the highest forecast growth rates for the decade 2000-2010 in the emissions scenarios of the Intergovermental Panel on Climate Change, Special Report on Emissions Scenarios (IPCC-SRES - figure 2, click to enlarge). This makes current trends in emissions higher than the worst case IPCC-SRES scenario. Fossil fuel and cement emissions released approximately 348 PgC to the atmosphere from 1850 to 2007.

The biggest increase in emissions has taken place in developing countries, largely in China and India, while developed countries have been growing slowly (figure 3, click to enlarge). The largest regional shift was that China passed the U.S. in 2006 to become the largest CO2 emitter, and India will soon overtake Russia to become the third largest emitter. Currently, more than half of the global emissions come from less developed countries. From a historical perspective, developing countries with 80% of the world’s population still account for only 20% of the cumulative emissions since 1751; the poorest countries in the world, with 800 million people, have contributed less than 1% of these cumulative emissions:
energy :: sustainability :: fossil fuels :: cement :: land-use :: deforestation :: carbon sink :: carbon flux :: carbon budget :: emissions :: climate change ::
After decades of improvements, the carbon intensity of the global economy, the carbon emitted per unit of Gross Domestic Product (GDP), was stalled during the period 2003-2005. This change was largely caused by China’s rapidly growing share in economic output and carbon emissions. Since 2005 China’s energy intensity (which underpins carbon intensity) has decreased (improved) by 1.2% in 2006 and 3.7% in 2007 compared to 2005 levels (according to the National Energy Administration in China).

Land use change was responsible for estimated net emissions of 1.5 PgC per year to the atmosphere. This is largely the difference between CO2 emissions from deforestation and CO2 uptake by reforestation. Emissions for 2006 and 2007 were extrapolated from the previous 25-year trend of 1.5 PgC per year. Land use change emissions come almost exclusively from deforestation in tropical countries with an estimated 41% from South and Central America, 43% from South and Southeast Asia, and 17% from Africa (figure 4, click to enlarge). An estimated 160 PgC were emitted to the atmosphere from land use change during the period 1850-2007 [1 Pg = 1 billion tons or 1000 x million tons].

Natural land and ocean CO2 sinks have removed 54% (or 4.8 PgC per year) of all CO2 emitted from human activities during the period 2000-2007. The size of the natural sinks has grown in proportion to increasing atmospheric CO2. However, the efficiency of these sinks in removing CO2 has decreased by 5% over the last 50 years, and will continue to do so in the future (figure 5, click to enlarge). That is, 50 years ago, for every ton of CO2 emitted to the atmosphere, natural sinks removed 600 kg. Currently, the sinks are removing only 550 kg for every ton of CO2 emitted, and this amount is falling.

The global oceanic CO2 sink removed 25% of all CO2 emissions for the period 2000-2007, equivalent to an average of 2.3 PgC per year. The size of the CO2 sink in 2007 was similar to that in the previous year but lower by 0.1 PgC compared to its expected increase from atmospheric CO2 growth. This was due to the presence of a La Nina event in the equatorial Pacific. The Southern Ocean CO2 sink was higher in 2007 compared to 2006, consistent with the relatively weak winds and the low Southern Annular Mode (a circumpolar pressure oscillation between Antarctica and southern mid-latitudes). An analysis of the long term trend of the ocean sink shows a slower growth than expected of the CO2 sink over the last 20 years.
Natural Forest Sink

Terrestrial CO2 sinks removed 29% of all anthropogenic emissions for the period 2000-2007, equivalent to an average of 2.6 PgC per year. Terrestrial ecosystems removed 2.9 PgC in 2007, down from 3.6 Pg in 2006, largely showing the high year-to-year variability of the sink. An analysis of the long term trend of the terrestrial sink shows a growing size of the CO2 sink over the last 50 years.

Based on the above findings about the evolution of carbon sources and sinks, the current global carbon dioxide flux emerges (figure 6, click to enlarge).

Conclusion
Anthropogenic CO2 emissions have been growing about four times faster since 2000 than during the previous decade, and despite efforts to curb emissions in a number of countries which are signatories of the Kyoto Protocol. Emissions from the combustion of fossil fuel and land use change reached the mark of 10 billion tones of carbon in 2007. Natural CO2 sinks are growing, but more slowly than atmospheric CO2, which has been growing at 2 ppm per year since 2000. This is 33% faster than during the previous 20 years. All of these changes characterize a carbon cycle that is generating stronger climate forcing and sooner than expected.


The Global Carbon Budget is the result of an international collaboration through the Global Carbon Project by Corinne Le Quéré (University of East Anglia/British Antarctic Survey, UK); Mike Raupach (CSIRO, Australia); Philippe Ciais (Commissariat a L'Energie Atomique, France); Thomas Conway (NOOA, USA); Chris Field (Carnegie Institution of Washington, USA); Skee Houghton (Woods Hole Research Center, USA); Gregg Marland (Carbon Dioxide Information Analysis Center, USA); Pep Canadell (CSIRO, Australia).

References:
Global Carbon Project: Carbon Budget 2007 [*.pdf] - September 26, 2008.

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Duke Energy and AREVA to jointly develop baseload biomass power plants in the U.S.

Two of the world's largest energy conglomerates, France's AREVA and Duke Energy, yesterday announced at the annual meeting of the Clinton Global Initiative, that they will jointly develop biomass power plants in the United States. The joint venture will be called ADAGE Biopower, which will facilitate the development of biopower plants that will use wood waste and other biomass to produce electricity. The project comes at a time when Americans face soaring energy costs, when climate change is becoming a tangible problem, and when other renewables find it difficult to deliver power in a reliable manner.

The AREVA/Duke agreement is one of the first biomass-to-electricity partnerships in the United States between major energy companies. Biomass is already the largest renewables sector in the EU, but now it seems the green baseload power solution is crossing the pond in earnest (less than a week ago, America's largest cooperative power supplier announced a $1.5 billion investment in biomass).

According to the agreement, AREVA will design and build biomass power plants. Duke Energy Generation Services (DEGS), a commercial power business unit of Duke Energy that owns and develops renewable energy, will manage operations. For each project, ADAGE will negotiate power purchase agreements and fuel contracts, and secure suitable sites. Hence, ADAGE will provide customers a fully integrated solution.

This project comes at exactly the right time as Americans face soaring energy prices and look to meet rising electricity demand with green energy sources. The ADAGE biopower facilities will respond to our nation's need for new baseload energy alternatives. - Jim Rogers, Duke Energy CEO

AREVA is developing a 50 megawatt (MW) design for ADAGE, with the intent of maximizing standardization wherever possible and take advantage of a fleet approach. A 50 MW ADAGE biomass plant would provide electricity for approximately 40,000 households and would avoid 400,000 tons of carbon dioxide (CO2) emissions per year compared to coal.

AREVA has extensive experience in the biomass sector, having designed and built more than 100 biopower facilities in Europe, Asia and South America with capacity of more than 2,500 megawatts. We are delighted to partner with Duke Energy, which has a growing portfolio of renewable assets throughout the U.S. market, and tremendous experience in operating power plants. - Anne Lauvergeon, CEO of AREVA

According to the companies, biopower has great potential in the United States. Federal and state environmental agencies consider biopower carbon neutral, a significant advantage over traditional power facilities. The impact of biopower facilities on America's economy is just as important; these facilities will create hundreds of new, green-collar jobs. In addition, the utilization of biomass as an abundant domestic resource reduces America's reliance on imported fuels.

Based on the strengths and experiences of Duke Energy and AREVA, ADAGE is well positioned to win a significant portion of the rapidly expanding U.S. biomass market. Biomass provides an alternative baseload power source for states concerned with CO2 emissions. We are committed to partnering with fuel suppliers, power companies and state and local communities to develop mutually beneficial projects. - Reed Wills, President of ADAGE

The U.S. Energy Information Administration (EIA) estimates the total installed capacity of wood biomass power generation to be 6,000 megawatts. EIA and several energy consulting firms predict that this figure may double over the next 10 years:
energy :: sustainability :: biomass :: bioenergy :: renewables :: power plants :: climate change :: energy security :: baseload ::

ADAGE will be headquartered in Chadds Ford, Pa. near Philadelphia. The environmental commitments outlined in the ADAGE strategic plan were featured at the Clinton Global Initiative 2008 Annual Meeting in New York.

AREVA is the leading U.S. nuclear vendor and a key player in the electricity transmission and distribution sector. AREVA Inc.'s 5,300 U.S. energy employees are committed to serving the nation and paving the way for the future of the electricity market. With 45 locations across the American nation and nearly $2 billion in energy revenues in 2007, AREVA Inc., through its subsidiaries, combines access to worldwide expertise and a proven track record of performance. In the U.S. and in more than 100 countries around the world, AREVA is engaged in the 21st century's greatest challenges: making energy available to all, protecting the planet, and acting responsibly toward future generations. AREVA Inc. is headquartered in Bethesda, Maryland.

Duke Energy, one of the largest electric power companies in the United States, supplies and delivers electricity to approximately 4 million U.S. customers in its regulated jurisdictions. The company has approximately 35,000 megawatts of electric generating capacity in the Midwest and the Carolinas, and natural gas distribution services in Ohio and Kentucky. In addition, Duke Energy has more than 4,000 megawatts of electric generation in Latin America, and is a joint-venture partner in a U.S. real estate company. Headquartered in Charlotte, N.C., Duke Energy is a Fortune 500 company traded on the New York Stock Exchange under the symbol DUK.

References:
ADAGE Biopower: Renewables: AREVA, Duke Energy to Jointly Develop Biomass Power Plants in the United States - September 24, 2008.

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UN report: green economy could create tens of millions of new jobs

A new, landmark study on the impact of an emerging global "green economy" on the world of work says efforts to tackle climate change could result in the creation of millions of new "green jobs" in the coming decades. The new report entitled Green Jobs: Towards Decent work in a Sustainable, Low-Carbon World, says changing patterns of employment and investment resulting from efforts to reduce climate change and its effects are already generating new jobs in many sectors and economies, and could create millions more in both developed and developing countries. In the renewable energy sector, by far the largest number of new green jobs will be generated in the bioenergy industry, which will see more jobs created than all other renewables combined.

However, the report also finds that the process of climate change, already underway, will continue to have negative effects on workers and their families, especially those whose livelihoods depend on agriculture and tourism. Action to tackle climate change as well as to cope with its effects is therefore urgent and should be designed to generate decent jobs.

Though the report is generally optimistic about the creation of new jobs to address climate change, it also warns that many of these new jobs can be "dirty, dangerous and difficult". Sectors of concern, especially but not exclusively in developing economies, include agriculture and recycling where all too often low pay, insecure employment contracts and exposure to health hazardous materials needs to change fast.

What's more, it says too few green jobs are being created for the most vulnerable: the 1.3 billion working poor (43 per cent of the global workforce) in the world with earnings too low to lift them and their dependants above the poverty threshold of US$2 per person, per day, or for the estimated 500 million youth who will be seeking work over the next 10 years.

According to the U.N. report, green jobs reduce the environmental impact of enterprises and economic sectors, ultimately to levels that are sustainable. The report focuses on "green jobs" in agriculture, industry, services and administration that contribute to preserving or restoring the quality of the environment. It also calls for measures to ensure that they constitute "decent work" that helps reduce poverty while protecting the environment.

The report says that climate change itself, adaptation to it and efforts to arrest it by reducing emissions have far-reaching implications for economic and social development, for production and consumption patterns and thus for employment, incomes and poverty reduction. These implications harbour both major risks and opportunities for working people in all countries, but particularly for the most vulnerable in the least developed countries and in small island States.

The report calls for "just transitions" for those affected by transformation to a green economy and for those who must also adapt to climate change with access to alternative economic and employment opportunities for enterprises and workers. According to the report, meaningful social dialogue between government, workers and employers will be essential not only to ease tensions and support better informed and more coherent environmental, economic and social policies, but for all social partners to be involved in the development of such policies.

Among key findings in the report:

- Some 300,000 people are currently employed in the global wind power industry; around 170,000 in solar PV; approximately 39,000 in hydropower and 1.2 million in the bioenergy sector. All renewables combined already employ more than 2.3 million people (graph, click to enlarge).

- The global market for environmental products and services is projected to double from US$1,370 billion per year at present to US$2,740 billion by 2020, according to a study cited in the report.

- Half of this market is in energy efficiency and the balance in sustainable transport, water supply, sanitation and waste management. In Germany for example, environmental technology is to grow fourfold to 16 per cent of industrial output by 2030, with employment in this sector surpassing that in the country's big machine tool and automotive industries.

- Sectors that will be particularly important in terms of their environmental, economic and employment impact are energy supply, in particular renewable energy, buildings and construction, transportation, basic industries, agriculture and forestry.

- Clean technologies are already the third largest sector for venture capital after information and biotechnology in the United States, while green venture capital in China more than doubled to 19 per cent of total investment in recent years.

- 2.3 million people have in recent years found new jobs in the renewable energy sector, with more than 1 million in the bioenergy sector alone, and the potential for job growth is huge. Employment in alternative energies may rise to 2.1 million in wind, 6.3 million in solar power and 12 million in bioenergy by 2030:

biomass :: bioenergy :: wind :: solar :: renewables :: employment :: energy :: sustainability :: developing countries :: poverty alleviation :: real economy :: green economy ::

- Renewable energy generates more jobs than employment in fossil fuels. Projected investments of US$630 billion by 2030 would translate into at least 20 million additional jobs in the renewable energy sector.

- In agriculture, 12 million could be employed in biomass for energy and related industries. In a country like Venezuela, an ethanol blend of 10 per cent in fuels might provide one million jobs in the sugar cane sector by 2012. [Editor's note: The example can be replicated for many other countries in the Global South].

- A worldwide transition to energy-efficient buildings would create millions of jobs, as well as "greening" existing employment for many of the estimated 111 million people already working in the construction sector.

- Investments in improved energy efficiency in buildings could generate an additional 2-3.5 million green jobs in Europe and the United States alone, with the potential much higher in developing countries.

- Recycling and waste management employs an estimated 10 million in China and 500,000 in Brazil today. This sector is expected to grow rapidly in many countries in the face of escalating commodity prices.

The report provides examples of massive green jobs creation, throughout the world, such as: 600,000 people in China who are already employed in solar thermal making and installing products such as solar water heaters; in Nigeria, a bio fuels industry based on cassava and sugar cane crops might sustain an industry employing 200,000 people; India could generate 900,000 jobs by 2025 in biomass gasification of which 300,000 would be in the manufacturing of stoves and 600,000 in areas such as processing into briquettes and pellets and the fuel supply chain; and in South Africa, 25,000 previously unemployed people are now employed in conservation as part of the 'Working for Water' initiative.

Pathways to green jobs and decent work
"A sustainable economy can no longer externalize environmental and social costs. The price society pays for the consequences of pollution or ill health for example, must be reflected in the prices paid in the marketplace. Green jobs therefore need to be decent work", the report says.

The report recommends a number of pathways to a more sustainable future directing investment to low-cost measures that should be taken immediately including: assessing the potential for green jobs and monitoring progress to provide a framework for policy and investment; addressing the current skills bottleneck by meeting skill requirements because available technology and resources for investments can only be deployed effectively with qualified entrepreneurs and skilled workers; and ensuring individual enterprises' and economic sectors' contribution to reducing emissions of greenhouse gases with labour-management initiatives to green workplaces.

The report finds that green markets have thrived and transformation has advanced most where there has been strong and consistent political support at the highest level, including targets, penalties and incentives such as feed-in laws and efficiency standards for buildings and appliances as well as proactive research and development.

The report says that delivery of a deep and decisive new climate agreement when countries meet for the crucial UN climate convention meeting in Copenhagen in late 2009 will be vital for accelerating green job growth.

The report was funded and commissioned by the UN Environment Programme (UNEP) under a joint Green Jobs Initiative with the International Labour Office (ILO), and the International Trade Union Confederation (ITUC) and the International Organization of Employers (IOE), which together represent millions of workers and employers worldwide. It was produced by the Worldwatch Institute, with technical assistance from the Cornell University Global Labour Institute.


The Green Jobs Initiative is a partnership established in 2007 between UNEP, the ILO and the ITUC, joined by the IOE in 2008. The Initiative was launched in order to promote opportunity, equity and just transitions, to mobilize governments, employers and workers to engage in dialogue on coherent policies and effective programs leading to a green economy with green jobs and decent work for all.

The ILO is a tripartite UN agency that brings together governments, employers and workers of its member states in common action to promote decent work throughout the world. IOE is recognized as the only organization at the international level that represents the interests of business in the labor and social policy fields. Today, it consists of 146 national employer organizations from 138 countries from all over the world.

ITUC is the International Trade Union Confederation. Its primary mission is the promotion and defense of workers' rights and interests, through international cooperation between trade unions, global campaigning and advocacy within the major global institutions. The ITUC represents 168 million workers in 155 countries and territories and has 311 national affiliates. UNEP is the voice for the environment in the United Nations system. It is an advocate, educator, catalyst and facilitator, promoting the wise use of the planet's natural assets for sustainable development.

References:
UNEP: Green Jobs: Towards Decent work in a Sustainable, Low-Carbon World - September 2008.

UNEP: Green jobs initiative.

UNEP: Labour and the Environment website.

The International Labour Organization website.

The International Trade Union Confederation website.

The International Organisation of Employers website.

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Largest U.S. power supply cooperative to invest up to $1.5bn in biomass power plants

After becoming the leading renewable energy source in Europe, biomass is beginning to grow big at the other side of the pond too. Oglethorpe Power Corporation (OPC), America's largest power supply cooperative, is going green in a major way by announcing plans to build as many as three 100 megawatt (MW) biomass electric generating facilities in Georgia. Designed to utilize woody biomass, one of the state’s most abundant renewable resources, the baseload power plants will provide power to OPC’s 38 member cooperatives, which supply electricity to nearly half of Georgia’s population.

With our abundant biomass resources, Georgia has the unique opportunity to expand our use of alternative energy, grow our economy and transform the way we provide energy to our citizens. Oglethorpe Power’s pioneering investment in alternative energy is consistent with our goal to grow, convert, and use biomass energy to power our homes and businesses. - Sonny Perdue, Governor of Georgia

OPC has secured options for five potential sites in Appling, Echols, Warren and Washington counties. The first two biomass power plants are scheduled to be built and placed into operation in 2014 and 2015; however, which of the five sites will host the first plants is still to be determined. A third unit could also be completed and placed into service in 2015.

Capital investment in the biomass plants will range from $400-500 million per facility, with each providing approximately 40 good-paying, full-time jobs. In addition, each plant will require an annual investment of more than $30 million for fuel stock alone and will create a need for potentially hundreds of new jobs in the state’s forestry industry.

The power plants will be steam-electric generation stations using conventional fluidized bed boiler/steam turbine technology. Fuel for the plants will consist of a woody biomass mixture, including processed roundwood (e.g. chipped pulpwood), primary manufacturing residue (e.g. wood waste from sawmills) and harvest residue (e.g. wood remaining in forests after clearing). The plants will be designed to allow for the co-firing of other types of biomass, such as pecan hulls and peanut shells. There are no plans to use any fossil fuels:
energy :: sustainability :: biomass :: bioenergy :: renewable :: wood :: efficiency :: co-firing :: Georgia ::

With 12 million people expected to call Georgia home by the year 2030, we will need more energy to meet the demand of our growing population. The addition of Oglethorpe Power’s biomass electricity plants will help supply Georgians with homegrown energy that is clean and renewable. - Chris Clark, executive director of the Georgia Environmental Facilities Authority (GEFA)

Smith added that the GEFA is committed to providing affordable and reliable power from a diverse mix of energy sources. Georgia has an abundant renewable biomass resource that is competitive with other available generation technologies. Unfortunately, our state is a poor location for wind energy and only has a modest potential for solar, thus making the case of biomass power generation as our best renewable alternative.

Employing environmentally responsible technologies, the biomass plants will meet all state and federal environmental requirements. The exact control technologies utilized will be determined as part of the permitting process. It is likely, however, that the plants will include filter baghouses for reduction of particulate emissions and selective non-catalytic reduction (SNCR) for control of NOx.

Depending on the location, water would be obtained either from onsite wells, nearby surface waters, from municipal sources or grey water from nearby industries. Each plant would be developed on a minimum of 150 acres of land to ensure an adequate buffer between the plant and its surroundings.


OPC is the America's largest power supply cooperative with approximately $5 billion in assets, serving 38 Electric Membership Corporations which, collectively, provide electricity to 4.1 million Georgia citizens. A proponent of conscientious energy development and use, OPC balances reliable and affordable energy with environmental responsibility and has an outstanding record of regulatory compliance. Its diverse energy portfolio includes natural gas, hydroelectric, coal, and nuclear generating plants with a combined capacity of approximately 4,700 MW, as well as purchased power. OPC was established in 1974 and is owned by its 38 member systems. It is headquartered in Tucker, Georgia.

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IFPRI: hungry Congo can become bread basket of the developing world

We have often referred to the agricultural potential of the world's poorest country, the Democratic Republic of Congo (DRC). The tragic contradiction is that this nation has the highest rate of undernourished and hungry people on the planet (70% of all Congolese), while at the same time it has the natural resources to become a major world food producer and exporter. In an interview with Reuters, the director of the International Food Policy Research Institute (IFPRI), Dr Joachim Von Braun, repeated how depressing this contradiction is, but he also offered some recipes for hope.

The giant Central African country has around 80 million hectares of non-forest land available for agriculture and could become a bread basket for the developing world, with some projections showing that it should be able to produce food for 3 billion people with optimal land use strategies. But decades of mismanagement, corruption, war and state collapse have kept out investors who need to pull this off.

The Congo River and its huge web of tributaries offer ample water for irrigation. The varied climate provides ideal conditions for a large number of crops.

The potential of Congo is huge. It could be another Brazil. If this plot of land were elsewhere in the world it could truly feed large amounts of the developing world. - Joachim von Braun, director general, International Food Policy Research Institute

But today, like much of Africa, Congo can't even feed itself. More than 70 percent of Congolese are affected by hunger and food insecurity, according to the U.N.'s Food and Agriculture Organisation. Infant malnutrition is on the rise.

Von Braun is clear: "You cannot eat potential". Instead, potential needs to be tapped by investment, and that investment in agriculture and rural infrastructure requires a lot of capital, a lot of long-term attention by government and the private sector.

The former Belgian colony is recovering from a devastating 1998-2003 war that killed an estimated 5.4 million people.

Eighty percent of land that could be farmed is either unused or under utilised, von Braun said. What farming exists is almost entirely subsistence agriculture. And amongst subsistence-economies, Congo performs worst. Yields for most crops are four to five times below what they could be with modest interventions.

A lack of roads to bring produce to market in Congo's urban centres mean much of what is consumed in cities is imported. A potential huge food exporter is a huge importer. As a result, Congo has been one of the countries worst hit by rising food prices linked to high oil and transport costs.

Agricultural investments = peace
Though much of this catastrophic state of affairs can be blamed on war and the limitations of a shattered economy, von Braun said the government's failure to prioritise farming has also stunted growth in the sector.

While 70 percent of Congolese earn a living in the sector, which makes up nearly half of Congo's economy, only 1 to 2 percent of state spending goes to investment in farming:
energy :: sustainability :: biomass :: bioenergy :: biofuels :: agriculture :: food :: poverty :: Congo ::

The investments in agriculture are investments in peace in this big country, but they need to be initiated now. Any waiting longer will undermine the economic growth.

He warned against investing heavily in industrial farming or the large-scale agriculture of Congo's colonial past. Instead he urged support for small farmers and for improving farming methods and equipment through microfinance programs.

Congo also needs to build roads so farmers can sell their crops to consumers, reducing imports to create a self-sustaining domestic sector that should one day be able to export, he said.

The gap couldn't be wider. This is the country where these two, reality and potential, are divided the widest of any significant large country. So you may call this depressing, or it can also be looked upon as a great opportunity. - Von Braun

Von Braun's words came after his participation in a workshop in Kinshasa, organised by the Congolese Ministry of Agriculture, at which one of the leading agricultural economists, Professor Eric Tollens of the Catholic University of Leuven, spoke too.

Prof. Tollens largely agrees with Von Braun's assessment. A critical problem is the lack of transportation infrastructures in Congo, which make it difficult for farmers to get their products to large cities, such as Kinshasa and Lubumbashi. High oil prices add to the troubles. The result is a growing dependence on imported food, which becomes ever more expensive.

But this trend offers an opportunity for Congolese farmers. Producing locally is becoming attractive, even with all the hurdles that scare off investors.

Tollens urges the Congolese government to pour much more money into the agricultural sector, because the rewards are so huge. Currently, this sector relies on handouts by the international donor community (see the recent overview by the FAO: Relaunching agriculture in war-torn DR Congo, one field at a time). But farming could be the biggest and most cost-effective engine for social and economic progress in the country and the region. If the state invests more in agriculture, it will create an environment of trust needed by foreign investors who want to enter the country's farming sector.

Picture: Agriculture supports 70% of the DR Congo's population of 60 million. Credit: FAO.

References:
Reuters: Hungry Congo could help feed the world: expert - September 18, 2008.

MediaCongo: RD Congo : L'affamé qui pourrait aider à nourrir le monde - September 22, 2008.

CongoForum: Congo: 70 procent bevolking is ondervoed - September 19, 2008.

FAO: Relaunching agriculture in war-torn DR Congo, one field at a time - September 2008.

Biopact: DR Congo debates its enormous biofuels potential - June 05, 2008

Biopact: UN's FAO: bright future for sustainable biofuels DR Congo - January 08, 2008

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Transparency International: corruption in low income countries "a humanitarian disaster"

The current energy and food crises, which affect the world's poorest countries most, are partly due to a lack of the capacity of these countries to cope with commodity price shocks. These low-income countries would be more resilient if investments would flow into agriculture, still the backbone of most of them, and into energy infrastructures. But investors, small and big, private and non-profit alike, face tremendous hurdles to start business in these countries. One of the main barriers is corruption. The new Corruption Perceptions Index (CPI) published by Transparency International today, states that corruption in low income countries amounts to nothing less than an "ongoing humanitarian disaster". Corruption takes a staggering $50 billion out of global development budgets, more than half of the total. The fight against poverty is at stake here.

With countries such as Somalia and Iraq among those showing the highest levels of perceived corruption, the 2008 CPI highlights the fatal link between poverty, failed institutions and graft. But other notable backsliders in the 2008 CPI indicate that the strength of oversight mechanisms is also at risk among the wealthiest.

In the poorest countries, corruption levels can mean the difference between life and death, when money for hospitals or clean water is in play. The continuing high levels of corruption and poverty plaguing many of the world’s societies amount to an ongoing humanitarian disaster and cannot be tolerated. But even in more privileged countries, with enforcement disturbingly uneven, a tougher approach to tackling corruption is needed. - Huguette Labelle, Chair of Transparency International

The Transparency International CPI measures the perceived levels of public-sector corruption in a given country and is a composite index, drawing on different expert and business surveys. The 2008 CPI scores 180 countries (the same number as the 2007 CPI) on a scale from zero (highly corrupt) to ten (highly clean).

Denmark, New Zealand and Sweden share the highest score at 9.3, followed immediately by Singapore at 9.2. Bringing up the rear is Somalia at 1.0, slightly trailing Iraq and Myanmar at 1.3 and Haiti at 1.4.

While score changes in the Index are not rapid, statistically significant changes are evident in certain countries from the high to the low end of the CPI. Looking at source surveys included in both the 2007 and 2008 Index, significant declines can be seen in the scores of Bulgaria, Burundi, Maldives, Norway and the United Kingdom. Similarly, statistically significant improvements over the last year can be identified in Albania, Cyprus, Georgia, Mauritius, Nigeria, Oman, Qatar, South Korea, Tonga and Turkey.

Whether in high or low-income countries, the challenge of reigning in corruption requires functioning societal and governmental institutions. Poorer countries are often plagued by corrupt judiciaries and ineffective parliamentary oversight. Wealthy countries, on the other hand, show evidence of insufficient regulation of the private sector, in terms of addressing overseas bribery by their countries, and weak oversight of financial institutions and transactions.

Stemming corruption requires strong oversight through parliaments, law enforcement, independent media and a vibrant civil society. When these institutions are weak, corruption spirals out of control with horrendous consequences for ordinary people, and for justice and equality in societies more broadly. - Huguette Labelle

Global fight against poverty in the balance
In low-income countries, rampant corruption jeopardises the global fight against poverty, threatening to derail the UN Millennium Development Goals (MDGs). According to TI’s 2008 Global Corruption Report, unchecked levels of corruption would add US $50 billion (€35 billion) - or nearly half of annual global aid outlays – to the cost of achieving the MDG on water and sanitation.

Not only does this call for a redoubling of efforts in low-income countries, where the welfare of significant portions of the population hangs in the balance, it also calls for a more focussed and coordinated approach by the global donor community to ensure development assistance is designed to strengthen institutions of governance and oversight in recipient countries, and that aid flows themselves are fortified against abuse and graft:
energy :: sustainability :: biomass :: bioenergy :: agriculture :: development :: poverty alleviation :: international aid :: investment :: corruption ::

This is the message that TI will be sending to the member states of the UN General Assembly as they prepare to take stock on progress in reaching the MDGs on 25 September, and ahead of the UN conference on Financing for Development, in Doha, Qatar, where commitments on funding aid will be taken

Prof. Johann Graf Lambsdorff of the University of Passau, who carries out the Index for TI, underscored the disastrous effects of corruption and gains from fighting it, saying, "Evidence suggests that an improvement in the CPI by one point [on a 10-point scale] increases capital inflows by 0.5 per cent of a country's gross domestic product and average incomes by as much as 4 per cent."

Corporate bribery and double standards
The weakening performance of some wealthy exporting countries, with notable European decliners in the 2008 CPI, casts a further critical light on government commitment to reign in the questionable methods of their companies in acquiring and managing overseas business, in addition to domestic concerns about issues such as the role of money in politics. The continuing emergence of foreign bribery scandals indicates a broader failure by the world’s wealthiest countries to live up to the promise of mutual accountability in the fight against corruption.

This sort of double standard is unacceptable and disregards international legal standards. Beyond its corrosive effects on the rule of law and public confidence, this lack of resolution undermines the credibility of the wealthiest nations in calling for greater action to fight corruption by low-income countries. - Huguette Labelle

The OECD Anti-Bribery Convention, which criminalises overseas bribery by OECD-based companies, has been in effect since 1999, but application remains uneven.

Regulation, though, is just half the battle. Real change can only come from an internalised commitment by businesses of all sizes, and in developing as well as developed countries, to real improvement in anti-corruption practices.

Across the globe, stronger institutions of oversight, firm legal frameworks and more vigilant regulation will ensure lower levels of corruption, allowing more meaningful participation for all people in their societies, stronger development outcomes and a better quality of life for marginalised communities.


References:
Transparency International: Persistently high corruption in low-income countries amounts to an “ongoing humanitarian disaster” - September 23, 2008.

Transparency International: CPI 2008 [*.pdf].

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Scientists: aggressive CO2 reductions needed now to counter destruction of marine life

How much carbon dioxide is too much? According to United Nations Framework Convention on Climate Change (UNFCCC) greenhouse gases in the atmosphere need to be stabilized at levels low enough to "prevent dangerous anthropogenic interference with the climate system." But scientists have come to realize that an even more acute danger than climate change is lurking in the world's oceans — one that is likely to be triggered by CO2 levels that are modest by climate standards.

Ocean acidification could devastate coral reefs and other marine ecosystems even if atmospheric carbon dioxide stabilizes at 450 ppm, a level well below that of many climate change forecasts, report chemical oceanographers Long Cao and Ken Caldeira of the Carnegie Institution's Department of Global Ecology in the journal Geophysical Research Letters.

The researchers' conclusions are based on computer simulations of ocean chemistry stabilized at atmospheric CO2 levels ranging from 280 parts per million (pre-industrial levels) to 2000 ppm. Present levels are 380 ppm and rapidly rising due to accelerating emissions from human activities, primarily the burning of fossil fuels.

This study was initiated as a result of Caldeira's testimony [*.pdf] before a Congressional subcommittee on Fisheries, Wildlife and Oceans in April of 2007. At that time he was asked what stabilization level would be needed to preserve the marine environment, but had to answer that no such study had yet addressed that question. Cao and Caldeira's study helps fill the gap.

Atmospheric CO2 absorbed by the oceans' surface water produces carbonic acid, the same acid that gives soft drinks their fizz, making certain carbonate minerals dissolve more readily in seawater. This is especially true for aragonite, the mineral used by corals and many other marine organisms to grow their skeletons. For corals to be able to build reefs, which requires rapid growth and strong skeletons, the surrounding water needs to be highly supersaturated with aragonite.

Before the industrial revolution, over 98% of warm water coral reefs were surrounded by open ocean waters at least 3.5 times supersaturated with aragonite. But even if atmospheric CO2 stabilizes at the current level of 380 ppm, fewer than half of existing coral reef will remain in such an environment. If the levels stabilize at 450 ppm, fewer than 10% of reefs would be in waters with the kind of chemistry that has sustained coral reefs in the past. - Long Cao

For the ecologically productive cold waters near the poles, the prospects are equally grim, says Cao. At atmospheric CO2 levels as low as 450 ppm, large parts of the Southern Ocean, the Arctic Ocean, and the North Pacific would experience a rise in acidity that would violate US Environmental Protection Agency water quality standards. Under those conditions the shells of many marine organisms would dissolve, including those at the base of the food chain:
energy :: sustainability :: biomass :: bioenergy :: fossil fuels :: carbon dioxide :: ocean acidification :: marine biodiversity :: oceans ::

If current trends in CO2 emissions continue unabated, says Caldeira, in the next few decades, we will produce chemical conditions in the oceans that have not been seen for tens of millions of years. We are doing something very profound to our oceans. Ecosystems like coral reefs that have been around for many millions of years just won't be able to cope with the change.

When you go to the seashore, the oceans seem huge. It's hard to imagine we could wreck it all. But if we want our children to enjoy a healthy ocean, we need to start cutting carbon emissions now. - Ken Caldeira

The Carnegie Institution has been a pioneering force in basic scientific research since 1902. It is a private, nonprofit organization with six research departments throughout the U.S. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary science. The Department of Global Ecology, located in Stanford, California, was established in 2002 to help build the scientific foundations for a sustainable future. Its scientists conduct basic research on a wide range of large-scale environmental issues, including climate change, ocean acidification, biological invasions, and changes in biodiversity.

Figure: Maps showing the distribution of ocean chemistry suitable for coral growth for different time periods, assuming “business-as-usual” CO2 emissions. Colors represent the chemical force promoting the development of coral skeletons.

Year 1765: Several hundred years ago, before the carbon dioxide emissions of the industrial revolution, nearly all coral reefs are found in the red-colored regions with a few in the orange and and very few in the yellow-green regions. No corals are found in the more blue and purple colored regions.

Year 1994: Already, as a result of historical carbon dioxide emissions, the area that is most suitable for coral growth has retreated to the western Pacific Ocean (and a little bit of the Indian Ocean). Most existing corals are already in marginal environments for coral growth.

Year 2040: Already, there is no place left in the ocean that is optimal for coral growth. In parts of the Southern Ocean, shells of some organisms, such as pteropods, are starting to dissolve.

Year 2099: By the end of the century, there is no place left in the ocean with the kind of ocean chemistry where corals are found growing naturally. Shells of marine organisms are dissolving through most of the Southern Ocean. Credit: Ken Caldeira, Testimony to the House Natural Resources Committee, Subcommittee on Fisheries, Wildlife and Oceans: Hearing on "Wildlife and Oceans in a Changing Climate."

References:
Cao, L., and K. Caldeira (2008), "Atmospheric CO2 stabilization and ocean acidification", Geophys. Res. Lett., doi:10.1029/2008GL035072, in press.

House Natural Resources Committee, Subcommittee on Fisheries, Wildlife and Oceans: Hearing on "Wildlife and Oceans in a Changing Climate." Written testimony by Dr. Ken Caldeira, Ph.D., Department of Global Ecology, Carnegie Institution of Washington: "Climate Change and Acidification are Affecting our Oceans" [*.pdf] - April 17, 2007.

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Interview: Ecovolve's Jason Aramburu discusses biomass pyrolysis and biochar

Ecovolve is a renewable energy start-up recently created by graduates from Princeton University. The company develops innovative small-scale biomass pyrolysis systems, which allow for the optimal use of a great variety of feedstocks. An important byproduct of the system is biochar, a carbon-rich material that can be sequestered in soils to make them more productive. Storing biochar into soils makes the energy obtained from Ecovolve's power plants carbon-negative.

By focusing on small-scale facilities, the company indicates it strongly believes in the power of distributed renewable energy generation.

Biopact's Laurens Rademakers spoke to Jason Aramburu, Ecovolve's chief technology developer and one of the company's founders.

Biopact: There are many different pyrolysis systems. Can you briefly describe the technology you developed?
Jason Aramburu: There are many different gasification and pyrolysis systems on the market and in-development, using a variety of processes (fast pyrolysis, slow pyrolysis, gasification etc). However, the vast majority of systems are only capable of processing one or two feedstocks, usually hardwoods or nutshells. Because of their low ash and moisture content, these feedstocks are typically the easiest to process, but represent a modicum of available biomass feedstocks. Ecovolve’s technology is designed to process a variety of bioenergy crops and agricultural residues cleanly and efficiently into desired end products.

Furthermore, most gasification systems require expensive gas cleaning equipment, which is only economical at a size of several megawatts or more. By contrast, we are developing a small-scale system that can be located near available biomass, eliminating the high cost of transporting raw feedstock. We circumvent many of the gas-cleaning issues by first converting from raw biomass into bio-oil.

Biopact: What exactly is bio-oil?
Aramburu: Bio-oil is a flammable hydrocarbon emulsion produced during fast pyrolysis of biomass. It’s not a true oil, but it has been successfully demonstrated as a viable substitute for No. 2 fuel oil. We are working on a combination of post-pyrolysis and in-situ upgrading processes to increase the quality and stability of our bio-oil for stationary power-gen applications. This will enable our fuel product to integrate into the existing stationary diesel generator infrastructure.

Biopact: There's some controversy over the amount of biomass that can be sourced in a sustainable manner. How large is the potential in the US?
Aramburu: Potential for growth of bioenergy crops on marginal land in the US is huge, and would not dramatically impact food production. However, an even greater amount of biomass is available in the form of waste wood and agricultural residue. Waste feedstocks have been traditionally the ‘holy-grail’ of pyrolysis and gasification, as they are cheap and readily available.

Biopact: You say Ecovolve's plants are small-scale, which makes distributed energy generation possible. What's your view on the feasibility of distributed renewables?
Aramburu: Distributed production is crucial for the proliferation of bioenergy technology. Raw biomass has a much lower energy density than bio-oil or fossil fuel. Transporting this raw feedstock over long distances to a large, centralized power plant can become a logistical nightmare. By bringing the plant to the biomass, we reduce transportation costs and carbon impact dramatically.

Biopact: I think the technology holds great potential for many developing countries. But when we talk about poorer countries, costs obviously become very important. Is Ecovolve's technology competitive with, say, wind or solar power?
Aramburu: Absolutely. From its inception Ecovolve has been focused on building technologies that are viable in both the developed and developing world without dependence on subsidies. We have designed our systems to be as simple as possible without sacrificing quality and efficiency. Systems can be easily constructed with used or refurbished equipment. In addition, bioenergy technologies can produce power on-demand, unlike intermittent renewables such as wind and solar.

Biopact: Ecovolve says its bioenergy concept yields 'carbon-negative' energy. Can you explain how this is possible?
Aramburu: Many people are confused by the concept of carbon-negative bioenergy. Our technology does not simply suck carbon dioxide out of the atmosphere to make energy. Plants accrete carbon over their lifetime by taking in CO2. This carbon is stored as biomass, and is typically released back into the atmosphere either through decomposition or combustion:
energy :: sustainability :: biomass :: bioenergy :: gasification :: pyrolysis :: bio-oil :: biochar :: carbon-negative ::

Our systems take in raw biomass and convert around 20% wt into biochar, a charcoal product that is typically 85-95% pure carbon. This biochar is considered an inert form of carbon, which will not leach into the atmosphere. If we process one tonne of biomass into energy, we actually release less carbon into the atmosphere than if that biomass were allowed to decompose or combust naturally.

What's more, because our small-scale systems use feedstocks close to the source, the carbon emissions released during the transportation of the biomass to the plant are negligible. This keeps the carbon balance of the energy produced 'negative'.

Biopact: Does Ecovolve offer consulting services on how to integrate biochar into the energy generation concept?
Aramburu: Absolutely. We believe that biochar is a much more cost-effective means of carbon sequestration than large-scale technologies such as carbon capture and storage. We are currently working with several farms and vineyards to integrate biochar into their existing value chain, and evaluate its effects on crop yield and soil water retention.

Biopact: Currently, biochar is not taken up into the Kyoto Protocol as a carbon sequestration method. Do you think this is a prerequisite for it to become commercially viable? Or will there be enough interest from the “voluntary” carbon market to back the concept?
Aramburu: Because of its relatively low production cost, biochar is one of the few carbon sequestration technologies that is viable even under a voluntary carbon market. However, its acceptance under Kyoto or a future agreement will only accelerate its adoption.

Biopact: I'm sure biochar and 'carbon-negative' energy will receive a lot of attention over the coming years. Ecovolve is one of the first companies to position itself explicitly within this new concept and with a technology that makes 'beyond zero emissions' more than a mere slogan. This is, however a new market, so you are both a market-maker and a risk-taker. How do you approach this new market? Which sectors do you focus on first?
Aramburu: You’re right, there are significant risks in any new technology market. That is why we believe the small-scale concept works so well. Because our plants are relatively low-cost, we can quickly develop and test new iterations in the field. We’ve focused on sectors we know well: small farming and wine production, and will eventually grow our customer base from there.

Biopact: What do you want Ecovolve to achieve in the longer term?
Aramburu: Our goal is to become a leader in the distributed generation market. We believe we take a unique approach to renewable energy production, and will eventually look to commercialize other small-scale renewable technologies.


Image: sample of bio-oil, one of the key products of Ecovolve's highly integrated pyrolysis and gasification concept.

References:
Ecovolve: Technology Overview - Biomass Pyrolysis + Gasification.

Biopact: Carbon-negative bioenergy making headway, at last - June 06, 2008

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Fighting carbon with carbon: new low-cost filter halves CO2-capture costs

Researchers in Wyoming report the development of a low-cost carbon filter that can remove 90 percent of carbon dioxide gas from the smokestacks of electric power plants that burn carbonaceous fuels. The cost of capturing CO2 with the new carbon filter was found to be around half that of the most cost-effective alternative currently available (amine absorption). When this technology is coupled to power plants that burn biomass, and the CO2 captured and sequestered, the energy from such a plant would be carbon-negative.

Ironically, the new filter is based on activated carbon, which can be made from charcoal - itself biomass which captured CO2 from the atmosphere. So in a sense, the researchers found a way to fight carbon with carbon...

Maciej Radosz and colleagues at Wyoming's Soft Materials Laboratory cite the pressing need for simple, inexpensive new technologies to remove carbon dioxide from smokestack gases. Coal-burning electric power plants are major sources of the greenhouse gas, and control measures may be required in the future.

The study describes a new carbon dioxide-capture process, called a Carbon Filter Process, designed to meet the need. It uses a simple, low-cost filter filled with porous carbonaceous sorbent that works at low pressures. Modeling data and laboratory tests suggest that the device works better than existing technologies at a fraction of their cost.

The scientists took current amine absorption techniques, which are known to separate CO2 well, as a reference for technical and economic comparisons with alternatives and with their own CO2 separating process. They calculated the efficiency and cost for the application of the different techniques to one type of flue gas. The reference cost for the amine technology to capture CO2 was found to be $47/ton, close to the often cited range of $40 to $50 per ton of compressed CO2:
energy :: sustainability :: biomass :: bioenergy :: biofuels :: carbon capture and storage :: geosequestration :: bioenergy with carbon capture :: carbon-negative :: activated carbon :: climate change ::

The alternatives were the following:

Ionic liquid absorption: too slow
Absorption in ionic liquids, which are known to be selective for CO2, was found to be problematic because CO2 sorption and desorption rates were observed to be very low. Therefore, the ionic liquid absorption option was abandoned. Instead, polymerized ionic liquids were found to be more attractive as solid materials for CO2 membranes and sorbents, as documented in other papers.

Pressure-induced transport: expensive for membranes
An example of a CO2-philic membrane-based alternative was investigated, where the CO2 driving force is due to a pressure difference between the permeate (ambient) and retentate. From among the many membrane materials that are known to be selective for CO2, relative to nitrogen, a recently synthesized membrane that was made of brominated poly(phenylene oxide) impregnated with 30% of silica particles was selected, because its permeability and its CO2/N2 selectivity were very high. This system was capable of recovering at least 90% of the CO2 with a purity of 90%; however, it was found to be very costly.

Because no firm basis for estimating the cost of the nanocomposite was available, the cost of recovered CO2 was difficult to estimate, but even for optimistic material cost assumptions, this cost is likely to be "much higher" than that of CO2 from the amine process.

Zeolite sorbents: problems with heat of sorption, moisture Sensitivity, and material and pressure costs
An example of a zeolite-13X PSA process was evaluated. In a first-pass economic evaluation, the sorption and desorption steps are assumed to be approximately isothermal, even though the CO2 heat of sorption on zeolite is substantial enough to cause the sorption temperature to increase. It has been reported that the heat of CO2 adsorption on zeolite is ~30 kJ/mol,56 which is ~10 times higher than that on activated carbon (~3 kJ/mol)35 at the same temperature 25 C and pressure 1 bar.

Another drawback of the zeolite sorbent is its moisture sensitivity, which requires much higher (say, over 300 C) drying temperatures than the minimum temperatures needed to remove CO2 alone, which means extra recovery costs.

However, ignoring these drawbacks in a first-pass economic evaluation lead to a cost of recovered CO2 that is approximately $70/ton, which is less than the membrane-recovered CO2, but is ~40% more than the amine benchmark cost.

The need to dry the zeolite will increase this cost. The main cost components are the steam cost, the compression cost, and the zeolite cost ($33/lb). A less-expensive sorbent, such as activated carbon (for example, $1-$2/lb), can reduce the material cost, but compression will still be required, if it is used in a PSA mode. Therefore, a PSA route was not evaluated further.

The researchers then looked at designing a capture process based on carbonaceous sorbents which overcome the above problems. The challenge was to make them at a low cost, with good CO2-selectivity, while at the same time ensuring that they are insensitive to moisture easy to regenerate. Ideally, such a sorbent should be selective to other flue-gas pollutants, such as NOx, SOx, mercury, and arsenic, which would allow for a multifunctional sorbent.

Some but not all carbon-rich materials, such as activated carbon, charcoal, other coal pyrolysis-derived materials, or even virgin coal, can satisfy these requirements and, hence, became the focus of the work. Four preliminary model carbon-rich materials were selected: activated carbon, charcoal, and virgin bituminous coal.

The bulk prices of these materials were conservatively estimated to be $1500/ton for activated carbon, $200/ton for charcoal, and $40/ton for coal.

The materials were then analysed for their sorption capacity, selectivity, rate, and thermal stability. The sorption capacity increases as the pressure increases and the temperature decreases. The activated carbon capacity was somewhat higher than that of charcoal, and much higher than that of coal, which correlates with the surface area and the degree and type of activation.

A more interesting trend emerged based on an ideal CO2/N2 sorption selectivity: increasing pressure substantially decreases the selectivity (it increases the nitrogen capacity to a far greater extent than it does the CO2 capacity), which points to a low-pressure sorption advantage.

All carbonaceous materials studied exhibited a rapid sorption rate. A typical time needed to nearly saturate these materials with CO2 was around 3 min at 25 C. This time increases as the temperature increases to 5-10 min at 75 C and 10-12 min at 110 C, with charcoal being on the low side and activated carbon being on the high side. Generally, the results suggested short sorption cycles at low temperatures.

The CO2 sorption was found to be reproducibly reversible, which suggested a good stability and easy desorption. 20 temperature cycles for activated carbon and 5 temperature cycles for charcoal between 25 C and 130 C did not affect the sorption capacity much.

These good qualities of the carbonaceous sorbents encouraged the researchers to design a filter based on them.

The new carbon filter
The scientists used the following design assumptions. The nominal CO2 recovery target for the filter was set at 90% and its purity target at 90%. In a first-pass approximation of the reference flue gas, the feed was assumed to contain 12% CO2, with the balance being nitrogen.

Low O2 sorption capacity was confirmed for activated carbon was determined to be as low as that of nitrogen, which suggested the CO2/oxygen selectivity would be similar to the CO2/nitrogen selectivity. Unless removed upstream of the carbon filter, which may be the case for existing power plants, SOx, NOx, and mercury were reported to have a high affinity for the activated carbon and, hence, were expected to be sorbed with CO2.

The sorption temperature of ~25 C was assumed not to change much during the sorption cycle, because the CO2 heat of sorption is on the low side. The sorption time is set at 2 min, the sorbent regeneration is set at 100 C, using direct-steam desorption for 2 min, based on preliminary breakthrough data taken in the laboratory.

The cooling-air stage time was also set at 2 min, which made the total cycle time for the preliminary example 6 min.

Without any attempt to optimize the vessel size, a cylindrical module was selected (3.5 m in diameter and 2.0 m in length). For the sorption-desorption-cooling cycle one would thus need 189 alternating vessels, 63 of which are in a sorption mode, 63 are in a desorption mode, and 63 are in an air-cooling mode.

Because the carbonaceous sorbents selected are known to be stable (that is, their capacity does not change much over time), it was assumed that no sorbent replacement would be required within 10 years. However, relaxing this assumption, for example, by replacing the sorbent more often, did not impact the cost of recovered CO2 too much.

Economic assumptions
To analyse the costs of capturing CO2 with the new filter, the following assumptions were made. Interest rates were set at 15%, the electricity cost at $0.07/kWh, the steam cost at $7/ton (or $3.2/MMBTU), and the annual maintenance and repair cost at 7% of the fixed capital investment. Manpower cost is a relatively minor component of the operating costs, and, hence, it was assumed to be approximately $1.5 million per year.

The carbon filter process was then evaluated for a vacuum regeneration case and a steam regeneration case, both before heat integration with the power plant and CO2 compression.

The scientists found that steam regeneration led to a significant cost reduction as compared to the amine benchmark.

Vacuum regeneration: comparable to benchmark
Flue gas at ~85 C is cooled to ~25 C with water before it is fed with a blower to the sorption unit. After the sorbent is almost saturated with CO2 for ~2 min, this unit switches to a 2 min regeneration cycle under vacuum, and then it alternates between the sorption and vacuum stages at ambient temperature.

The major cost items are associated with the vacuum pump. The total cost of the recovered CO2 is approximately $37/ton, which is comparable to that of the amine benchmark case.


Thermal regeneration with steam or hot CO2: much better than benchmark
An isobaric process with direct-steam or hot-CO2 regeneration is shown in Figure 2. Both sorption and desorption occur at ambient pressure. The feeding section and the sorption cycle are the same as those in the previous case. Instead of vacuum regeneration, however, the saturated sorbent bed switches to a steam heating cycle and then to an air-cooling cycle to bring the bed temperature to near-ambient temperature.

The major cost items were steam and electricity, and the total cost of the recovered CO2 is approximately $20/ton for activated carbon, which is much less than that for the amine benchmark.

The $20/ton low-pressure CO2 cost must be corrected for compression to make CO2 ready for transport. The compression cost, from ambient to a pipeline pressure (e.g., 2000 psi) was estimated to add $7/ton. Therefore, the total cost of compressed, pipeline-ready CO2 for a power-plant integrated activated carbon filter would be approximately $27/ton CO2.

Effect on electricity prices
Adding a carbon capture unit to a power plant will affect the electricity cost and, hence, the profitability. For the activated carbon filter, an approximate electricity cost change was plotted relative to carbon capture credits.

A run of costing models showed that credits of $30/ton can effectively reduce the electricity production cost by 10%, credits of $20/ton can leave the electricity cost unchanged, and zero credits can increase the electricity cost by ~30%.

Conclusion
The low-pressure carbon filter process proposed to capture carbon dioxide (CO2) from flue gas showed great potential to reduce costs. The filter is filled with low-cost carbonaceous sorbents, such as activated carbon, which has a high capacity to retain CO2 but not nitrogen (N2), which means a high CO2/N2 selectivity.

The carbon filter process can recover at least 90% of the flue-gas CO2 of 90% purity at a fraction of the cost normally associated with the conventional amine absorption process.

The filter can produce low-cost CO2, because it requires neither expensive materials nor expensive flue gas compression, and it is easy to heat integrate with an existing power plant or a grassroots plant without affecting the cost of the produced electricity too much.

References:
Maciej Radosz, Xudong Hu, Kaspars Krutkramelis, and Youqing Shen, "Flue-Gas Carbon Capture on Carbonaceous Sorbents: Toward a Low-Cost Multifunctional Carbon Filter for 'Green' Energy Producers." Industrial & Engineering Chemistry Research, May 21, 2008.

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