Waste2tricity!

This British venture seeks to take carbon based waste, either municipal solid waste (MSW) or waste from business and industry and convert it to clean electricity, reducing the amount of garbage going into landfills and giving U.K electric companies a much needed boost. This is a very important step towards solving many environmental issues plaguing us today as it is also common knowledge that the majority of electricity generation and waste disposal methods currently in widespread use are not very environmentally friendly.

The system involves sorted carbon waste, including plastics, paper, cardboard, food and other plant material, entering a plasma gasification chamber and being turned into syngas by the application of very high temperatures (+6000°C). This process has advantages over incineration, which has not been adopted on a large scale for the conversion of MSW into power because of the low efficiency, fears over emissions and waste from incineration or from existing gasification systems. Compared to incineration systems the Waste2tricity system produces fewer pollutant gases, tar, ash and fly ash and the main by-product, vitrified slag, is inert and can be used as road-building aggregates, with the added benefit of reducing demand for gravel extraction.

Waste2Tricity will develop the process in two stages. In Stage 1 the cleaned syngas will be fed into an internal combustion engine (ICE) generator, with an average generation efficiency of about 30%. In Stage 2, the syngas will be processed and converted to hydrogen and the ICEs will be replaced by new generation alkaline fuel cells, which have the highest conversion efficiency of hydrogen to electricity of any process. By the combination of plasma gasification with fuel cells Waste2tricity claims the net output of electricity to the UK National Grid could increase by over 50% compared to existing technologies and that the new generation fuel cells will increase the net output of electricity by a minimum of 60% over an internal combustion engine generation system or by 130% over a steam turbine system. Waste2Tricity also estimates that the cost of generating electricity can be less than UKP3p (USD$0.04cents) per KWh at today's prices.

This is a very impressive system that will go a long way to improving the environment as facilities could be built directly on landfills thereby utilizing existing roads and saving valuable land. Also, not only will this help reduce landfills and probably the need for them altogether, but the main by-product, inert vitrified slag can be used as a very durable road building aggregate. I am very pleased with the pace at which the British are going in trying to solve environmental problems. I wrote an article last month on CO2 absorbent cement developed by some British scientists and now this "waste2ricity" system is just another reminder to the rest of us in the United States how far we seem to lag when it comes to finding new technologies to clean up the environment and yet we produce most of the world's pollution.

Image obtained from: www.gizmag.com

British Engineers Develop CO2 Absorbent Cement

Cement, a vast source of planet-warming carbon dioxide, could be transformed into a means of stripping the greenhouse gas from the atmosphere, thanks to an innovation from British engineers and scientists.

The new environmentally friendly formulation means the cement industry could change from being a "significant emitter to a significant absorber of CO2," says Nikolaos Vlasopoulos, chief scientist at London-based Novacem, whose invention has garnered support and funding from industry and environmentalists.

The new cement, which uses a different raw material, certainly has a vast potential market. Making the 2bn tonnes of cement used globally every year pumps out 5% of the world's CO2 emissions (more than the entire aviation industry). The long-term trends are upwards: a recent report by the French bank Credit Agricole estimated that, by 2020, demand for cement will increase by 50% compared to today.

Making traditional cement results in greenhouse gas emissions from two sources: it requires intense heat, and so a lot of energy to heat up the ovens that cook the raw material, such as limestone. That then releases further CO2 as it burns. But, until now, no one has found a large-scale way to tackle this fundamental problem.

Novacem's cement, based on magnesium silicates, not only requires much less heating, it also absorbs large amounts of CO2 as it hardens, making it carbon negative. Set up by Vlasopoulos and his colleagues at Imperial College London, Novacem has already attracted the attention of major construction companies such as Rio Tinto Minerals, WSP Group and Laing O'Rourke, and investors including the Carbon Trust.

The company has just started a £1.5m project funded by the government-backed Technology Strategy Board to build a pilot plant. If all goes well, Vlasopoulos expects to have Novacem products on the market within five years.

Jonathan Essex, a civil engineer at the building consultancy Bioregional who also sits on the environment and sustainability panel for the Institution of Civil Engineers, welcomed Novacem's ideas to tackle the carbon impact of cement. "In the UK the climate bill commits us to reduce CO2 emissions, and every sector should play its part. The construction industry needs to take greater responsibility for its own environmental impact." Essex said that, if Novacem can make their cement at a competitive price, the next step could be to take even more CO2 emissions out of the process by using renewable energy to fire the furnaces.

According to Novacem, its product can absorb, over its life-cycle, around 0.6 tonnes of CO2 per tonne of cement. This compares to carbon emissions of about 0.4 tonnes per of standard cement. "From that point of view, it's attractive," said Rachael Nutter, head of business incubators at the Carbon Trust. "The real challenge is what is the supply chain, who do you need to partner with to take it to market? The million-dollar question is what are the applications of it? If it ends up as decorative applications such as floor tiles, it's quite interesting but not as much as if you get into load-bearing structural stuff."

Previous attempts to make cement greener have included adding more aggregate to a concrete mixture, thereby using less cement. But this still does not tackle the problem of the carbon emissions from making the cement in the first place. Other systems use polymers in the mix, but none have yet made a significant impact on the market.

A spokesperson for the British Cement Association expressed a sceptical note, saying that though there was much ongoing laboratory work on new types of cement, there were also problems. "The reality is that the geological availability, and global distribution, of suitable natural resources, coupled with the extensive validation needed to confirm fitness-for-purpose, make it highly unlikely that these cements will a be realistic alternative for volume building."

Vlasopoulos responded that magnesium silicates are abundant worldwide, with 10,000 billion tonnes available, according to some estimates. "In addition, the production process of our cement is of a chemical nature, which means it can also utilise various industrial byproducts containing magnesium in its composition." He is confident the material will be strong enough for use in buildings but acknowledged that getting licenses to use it will take several years of testing.

If test reveal that this new cement is indeed an absorber of CO2, I hope it will begin to be implemented in many of the projects that will hopefully be commissioned this year. Unfortunately, what I see happening is that the ultra-conservative Building Materials Industry will cry and whine again (as they always do when it comes to things that actually make sense) about how they really don't know this new material and how they prefer to work with what they know: Portland cement. Hence they'll help to continue to keep the United States behind the rest of the world in building construction technology.

Image obtained from www.guardian.co.uk

Schools Lull Children to Sleep

A study conducted by Dr. Dejan Mumovic, lecturer in environmental design and engineering at the Barlett University in England, schools constructed under the building schools for the future (BSF) initiative have been found to have very poor ventilation and increased "air tightness." This has caused a build up of CO2 in classrooms making students feel sleepy and hence affecting their learning performance.

In his study, Mumovic compared ten schools built 50 years ago to the same number of schools built under the BSF program in the last 5 years and found that in terms of the ventilation rates and IAQ, nothing has changed. This has stemmed from the government's rush to implement the BSF program, which seeks to have all new schools at zero-carbon by 2016, and has led to increased focus on heat loss and natural ventilation rather than carbon levels for which the program was originally intended.

Prof. Derek Clements-Croome of Reading University tested students from the 1o schools and found increased levels of CO2 in the blood stream and brain which can cause increased drowsiness and decrease learning performance.

I don't know if there are just more CO2 tests being done in the UK or that there have higher levels there than in the United States, but i seem to hear way more about high carbon levels in buildings in England. All in all, these are very important tests and can only help improve the IAQ and general user experience.

For more info, check www.thisislondon.co.uk/standard/article-23605389-details/Children+'falling+asleep+in+stuffy+eco-classrooms'/article.do
Image obtained from InMagine

Spotlight On England's Biggest C02 Offenders

In the United Kingdom, a test done to determine the level of C02 emissions from many of the prominent buildings in the country yielding astounding results with many of the so called green buildings receiving failing grades. This test, which came about as a direct result from the new national law to curb carbon emissions and improve energy efficiency in the country, sought to measure emissions from buildings to determine which needed to be redesigned and upgraded to be more efficient.

Approximately 18,000 buildings, including town halls, schools, museums and banks have now been tested by the National Department for the Environment to discover their level of energy efficiency and assign a grade, where an "A" is the highest obtainable and a "G" is a failing grade. From the bottom up, both the Palace of Westminster and the Bank of England scored a G consuming enough energy to pump out 21,356 tonnes of C02 a year.

Many newer buildings, initially marketed as green also fared badly calling into question many of the sustainable claims made by architects and developers. For example, London's city hall scored an abysmal E despite Foster & Partners initially describing it as "a virtually non-polluting public building." The building for the Treasury Headquarters in Whitehall and Libeskind's Imperial War Museum shared a similar grade even though the former had received a complete refurbishment six years ago and both projects were supposed to set "new environmental standards in their respective counties."

Many of the other evaluated buildings in the country received an average grade of a D with only 22 buildings scoring an A (less than 1%) also showing that almost a fifth of all carbon dioxide emissions in the U.K are caused by non-residential buildings. Matt Bell, director of public affairs at the commission for Architecture and the Built Environment stated, "We review about 350 significant new build projects a year at design phase and hear a lot of 'greenwash.' The knowledge that from now on, this performance will be objectively measured should put an end to all those baseless claims."

All these results have made the government pledge to make all new public buildings zero emission by the year 2018 but it looks like they'll have to start in their own backyard as the Department of Environment's main office received an E. So now we have to wonder if "Green" has just become a label slapped on to projects to make them more salable and again ask the question, "who really designs green?"

Image (Imperial War Museum, Manchester) obtained from www.guardian.co.uk