Posts Tagged ‘greenhouse gases’
Recent News on Energy and the Environment 12.12.08
Posted by: Karl Ramjohn
Some recent articles featured on the Energy Environment News Portal, on current and emerging issues related to energy and the environment
> Wind, Water and Sun superior to Biofuels, Nuclear and Coal for Clean Energy
> Degraded grasslands better option for biofuels
> UN Climate Chief Lowers Expectations For 2009 Deal
> Poznan: Indigenous Rights Row Threatens Rainforest Protection Plan
Recent News on Energy and the Environment 05.12.08
Posted by: Karl Ramjohn
Some recent articles featured on the Energy Environment News Portal, on current and emerging issues related to energy and the environment
> Canada oil sands allegedly threatening millions of birds
> HSBC to curb palm oil lending, review oil sands
> Youth Embarassed By U.S. Delegation at Climate Conference
> Man-made noise in world’s seas threaten wildlife
> UK urged to ditch “unreliable” wind turbines for nuclear power
> Climate still a top concern despite financial crisis: Survey
> EU economic rescue plan puts focus on energy efficiency and greener products
Sustainable Energy (Video)
Posted by: Karl Ramjohn
Sustainable Energy
This might not add much to the debate and discussion on “Sustainable Energy”, but it has a somewhat different presentation format:
More videos on sustainable energy, climate and related: Geo Energy Network Media
Modelling civilization as “heat engine” could improve climate predictions
Posted by: Karl Ramjohn
An interesting article from Environmental Research Web (November 27, 2008) on a possible conceptual approach to modelling human activities (and the built environment) and how they interact with climate systems (and the natural environment).
—> Modelling civilization as ‘heat engine’ could improve climate predictions – environmentalresearchweb
The extremely complex process of projecting future emissions of carbon dioxide could be simplified dramatically by modelling civilization as a heat engine. That is the conclusion of an atmospheric physicist in the US, who has shown that changes in global population and standard of living correlate to variations in energy efficiency. This discovery halves the number of variables needed to make emissions forecasts and therefore should considerably improve climate predictions, he claims.
Computer models used to predict how the Earth’s climate will change over the next century take as their input projections of future manmade emissions of carbon dioxide. These projections rely on the evolution of four variables: population; standard of living; energy productivity (or efficiency); and the “carbonization” of energy sources. When multiplied together, these tell us how much carbon dioxide will be produced at a given point in the future for a certain global population. However, the ranges of values for each of the four variables combined leads to an extremely broad spectrum of carbon dioxide-emission scenarios, which is a major source of uncertainty in climate models.
Timothy Garrett of the University of Utah in the US believes that much of this uncertainty can be eliminated by considering humanity as if it were a heat engine (arXiv:0811.1855). Garrett’s model heat engine consists of an entity and its environment, with the two separated by a step in potential energy that enables energy to be transferred between the two. Some fraction of this transferred energy is converted into work, with the rest released beyond the environment in the form of waste heat, as required by the second law of thermodynamics.
However, the work is not done on some external task, such as moving a piston, but instead goes back to boosting the potential across the boundary separating the entity from the environment. In this way, says Garrett, the boundary “bootstraps” itself so that it can get progressively bigger and bigger, resulting in higher and higher levels of energy consumption by the entity.
Recent News on Energy and the Environment 26.10.08
Posted by: Karl Ramjohn
Some recent articles featured on the Energy Environment News Portal, on current and emerging issues related to energy and the environment
> Australia: Financial Crisis takes toll on Carbon Scheme
> Additive to make tallow-based biofuel more viable
> Secrets From Within Planets Pave Way For Cleaner Energy
> Nanotechnology – Not That Green?
Biomass Energy – Sustainable Solution to Livestock Wastes?
Submitted by: Karl Ramjohn
Livestock production is an important food supply and economic activity, the primary goal of which is to supply high-quality protein (meat, eggs, dairy products, etc) for the needs of human populations. The animals serve as concentrated sources of typically dispersed nutrients. Subsidiary products may include leather, fertilizers, inputs to animal feeds, and energy sources (biofuels). The challenge of sustainable livestock production systems is to promote food security in a manner which is economically viable and socially acceptable without causing land degradation or irreversibly affecting ecological resilience. As such, sustainability must promote a favourable cost – benefit ratio, and as far as possible avoid reducing the set of options available to future generations. This has very significant social considerations, as seemingly obvious solutions may be difficult to implement, as they may be biologically but not economically sustainable.
The recycling of materials, and thus minimizing the generation of wastes is a basic process which must be implemented to meet the demands of sustainability in developed and developing countries alike. Systems which utilize energy produced from biomass are examples of energy-recycling systems. All biomass originates through carbon dioxide fixation by photosynthesis. Consequently, biomass utilization may be regarded as a critical component of the global carbon cycle of the biosphere.
Most biomass cannot be directly utilized, and must undergo some sort of transformation before being converted to fuel. Biological processes for the conversion of biomass to fuels include ethanol fermentation by yeast or bacteria, and methane production by microbial consortia under anaerobic conditions. Unlike ethanol fermentation, anaerobic digestion for methane production utilizes organic materials containing carbohydrates, lipids and proteins. Waste materials from livestock production are applicable to anaerobic digestion, with the added advantage of reducing environmental impacts, such as unpleasant odours and water pollution.
Methane fermentation is therefore a versatile biotechnology, which can convert almost all types of polymeric materials to methane and carbon dioxide under anaerobic conditions. It converts the waste products of livestock systems into useful products of commercial value, while reducing the environmental costs associated with other methods of livestock waste disposal. As such, it offers an effective means of pollution reduction, superior to that achieved by conventional aerobic processes. It is also an efficient method of converting unused biomass resources (crop residues, forestry, industrial/municipal and livestock wastes) into biofuels and fertilizers.
The digested slurry (by-product of methane production) retains the nitrogen and other mineral nutrients which are lost when biomass wastes are directly burned, while reducing BOD/COD. Methane is a principal constituent of natural gas, and extraction of this resource from livestock waste is a small-scale but useful method of supplementing extraction from geologic deposits. It also mitigates the problems associated with slow decomposition on the land surface, in the context of the large “greenhouse effect” of methane – up to 25 times that of carbon dioxide. The pathogens are also destroyed, reducing the health effects of the digested biomass, which also does not attract flies or rodents.
Biomass conversion is economically feasible within the constraints of scale and location. The main problems associated with biomass digestors is the relatively high price of implementation, the fact that the technology is still somewhat experimental, and the high standard of management and maintenance required.
Overriding issues in the future of biological energy systems are the overall efficiency of converting biomass to fuels, the economics of such processes, their environmental impacts, their competitiveness with thermochemical processes for biomass, and their compatibility with evolving economic and political structures.
Related:
http://tropicalenv.conforums.com/index.cgi?board=landuse04&action=display&num=1218573241
Algae – The Solution to Energy Crisis & Climate Change?
From: World Business Council for Sustainable Development (WBCSD): AFP – July 10, 2008
As the world mulls over the conundrum of how to satisfy a seemingly endless appetite for energy and still slash greenhouse gas emissions, researchers have stumbled upon an unexpected hero: algae. So-called microalgae hold enormous potential when it comes to reining in both climate change, since they naturally absorb large amounts of carbon dioxide, as well as energy production, since they can easily be converted to a range of different fuel types.
“This is certainly one of the most promising and revolutionary leads in the fight against climate change and the quest to satisfy energy needs,” Frederic Hauge, who heads up the Norwegian environmental group Bellona, told AFP. The idea is to divert exhaust spewed from carbon burning plants and other factories into so-called “photobioreactors”, or large transparent tubes filled with algae. When the gas is mixed with water and injected into the tubes, the algae soak up much of the carbon dioxide, or CO2, in accordance with the principle of photosynthesis. The pioneering technique, called solar biofuels, is one of a panoply of novel methods aiming to crack the problem of providing energy but without the carbon pollution of costly fossil fuels — with oil pushing 140 dollars a barrel and supplies dwindling — or the waste and danger of nuclear power.
Studies are underway worldwide, from academia in Australia, Germany and the US, to the US Department of Energy, oil giant Royal Dutch Shell and US aircraft maker Boeing. This week alone, Japanese auto parts maker Denso Corp., a key supplier to the Toyota group, said it too would start investigating, to see if algae could absorb CO2 from its factories. The prestigious Massachusetts Institute of Technology (MIT), for one, has successfully tested the system, finding that once filtered through the algae broth, fumes from a cogeneration plant came out 50-85 percent lighter on CO2 and contained 85 percent less of another potent greenhouse gas, nitrogen oxide. Once the microalgae are removed from the tubes they can easily be buried or injected into the seabed, and thus hold captive the climate changing gases they ingest indefinitely. And when algae grown out in the open are used in biomass plants, the method can actually produce “carbon negative” energy, meaning the energy production actually drains CO2 from the atmosphere. This is possible since the microalgae first absorbs CO2 as it grows and, although the gas is released again when the biomass burns, the capturing system keeps it from re-entering the air. “Whether you are watching TV, vacuuming the house, or driving your electric car to visit friends and family, you would be removing CO2 from the atmosphere,” Hauge said.
Instead of being stored away, the algae can also be crushed and used as feedstock for biodiesel fuel — something that could help the airline industry among others to improve its environmental credentials. In fact, even the algae residue remaining after the plants are pressed into biodiesel could be put to good use as mineral-rich fertiliser, Hauge said “You kill three birds with one stone. The algae serves at once to filter out CO2 at industrial sites, to produce energy and for agriculture,” he pointed out. Compared with the increasingly controversial first-generation biofuels made from food crops like sunflowers, rapeseed, wheat and corn, microalgae have the huge advantage of not encroaching on agricultural land or affecting farm prices, and can be grown whenever there’s sunlight. They also can yield far more oil than other oleaginous plants grown on land. “To cover US fuel needs with biodiesel extracted from the most efficient terrestrial plant, palm oil, it would be necessary to use 48 percent of the country’s farmland,” according to a recent study by the Oslo-based Centre for International Climate and Environmental Research. “The United States could potentially replace all of its petrol-based automobile fuel by farming microalgae on a surface corresponding to five percent of the country’s farmland,” the study added.
As attractive as it may seem however, the algae solution remains squarely in the conception phase, with researchers scrambling to figure out how to scale up the system to an industrial level. Shell, for one, acknowledged on its website some “significant hurdles must be overcome before algae-based biofuel can be produced cost-effectively,” especially the large amounts of water needed for the process. In addition, further work is needed to identify which species of algae is the most effective.
Further discussions related to the topic of this post:
http://www.oilgae.com/forum/viewforum.php?f=1
http://www.worldofrenewables.com/showthread.php?t=16547
http://www.its2hot.in/viewtopic.php?f=28&t=158
http://www.sustainabilityforum.com/forum/climate-change/2762-algae-solution-climate-change.html
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