Selasa, 16 Maret 2010

Welsh Company Makes Recyclable Homes from Recycled Plastic


Written by Tina Casey
When you mash green jobs together with affordable housing and recycled plastic, something interesting is bound to happen, and it’s happening in Wales.  The Welsh company Affresol has launched a line of  low cost homes and modular buildings that use recycled plastic as a core structural material.  Affresol plans to market some of its product as homes that can fulfill community affordable housing needs while creating new green jobs in recycling.
Affresol’s primary innovation is Thermo Poly Rock, a material composed mainly of recycled mixed plastics, which pours and sets like concrete.  According to Affresol, Thermo Poly Rock has a number of advantages over concrete, but its main contribution could be a sustainable approach to housing in which homes are built on a semi-temporary basis with life cycle in mind.



Affresol and Recycled Plastic

According to a recent story in the Daily Mail, the plastic from about 9,000 recycled televisions or 7,200 computers is what it takes to build a three-bedroom house framed with Thermo Poly Rock.  That’s about 18 tonnes of recycled plastic (a tonne is 1,ooo kilograms and a U.S. ton is 909 kilograms).  Thermo Poly Rock is a thermoset polymer, which is a liquid plastic that sets in a permanent rigid state after processing.  Affrasol claims that the product is stronger than concrete with better flex and tensile properties.  Its recyclability is not so obvious at first glance because thermoset polymers typically cannot be melted down again and reformed into a new shape (for this reason thermosets were generally considered non-recyclable), but it’s possible that thermoset polymers can be recycled in granulated form and combined with other materials to manufacture a durable new product (something similar is going on in tire recycling).



Rabu, 06 Januari 2010

Boat Made of 16,000 Plastic Bottles to Sail from Cali to Australia


Published on March 22nd, 2009
   





British environmentalist David de Rothschild, author of Live Earth Global Warming Survival Handbook, met with the San Francisco Conservation Corps on Wednesday to talk about “Plastiki,” a 60-foot catamaran made from recycled plastic (except for the masts), which he’ll use to sail from San Francisco to Australia: an 11,000 mile voyage!
The boat is made up of about 16,000 plastic bottles and is an “effort to raise awareness of the recycling of plastic bottles, which he says are a symbol of global waste.” saysRothschild. Skin-like panels made from recycled PET, a woven plastic fabric, will cover the hulls and a watertight cabin, which sleeps four. Only about 10 percent of the Plastiki will be made from new materials.
Two wind turbines and an array of solar panels will charge a bank of 12-volt batteries, which will power several onboard laptop computers, a GPS and SAT phone. He went on to say, “It’s all sail power. The idea is to put no kind of pollution back into the atmosphere, or into our oceans for that matter, so everything on the boat will be composted. Everything will be recycled. Even the vessel is going to end up being recycled when we finish.”
While as noble as that sounds, I can’t help but think that if this boat makes it…it will be on display for quite sometime. Maybe never recycled?


Who Needs a Phone Book?

Published on August 10th, 2009
 


As the Internet becomes the resource more Americans turn to for phone numbers, lawmakers are beginning to examine the proliferation of unwanted phone books — and their environmental impact. A Minnesota legislator, Rep. Paul Gardner, has introduced state legislation to allow consumers to opt-out of receiving the paper directories, but is taking a wait-and-see approach on a voluntary initiative by phone services to allow convenient opt-out. Several other states have considered such a law, but none has passed.
Minnesota’s Pollution Control Agency estimates that only 12% of discarded phone books were recycled in 2006, meaning 11,538 tons of them ended up as municipal solid waste.  This is despite a 1992 state law that bans disposal of phone books as solid waste and requires phone companies to make recycling options available.  The agency also figures that if about 50% of state consumers opted out of receiving phone books, this would prevent 14,000 metric tons of “carbon dioxide equivalent.”  A Twin Cities blogger is so tired of receiving phone books he doesn’t need that he posted a video of his comical effort to return one. Meanwhile, a private nonprofit group, Yellowpagesgoesgreen.org, has signed up more than 3,000 Minnesotans who want to opt out. And there are other options.
Gardner is also the author of a proposed product stewardship law for the state.
Image credit:  Minnesota Pollution Control Agency.

Curbside Vs. Deposit and GHG Reduction

Written by Dave Dempsey
Published on December 15th, 2009


The beverage container industry continues to fight state and national container legislation despite evidence that such laws could contribute significantly to greenhouse gas reduction while providing energy, recycling and litter control benefits. The industry says community recycling programs, which put the cost burden on communities rather than container manufacturers, are a superior system for processing bottles and cans.

The latest weapon in the industry’s arsenal is a report commissioned by itself; the American Beverage Association (ABA) that says bottles, cans and packages made by its members are easily recyclable because community recycling programs that can handle them serve an overwhelming majority of Americans. Getting more consumers to capitalize on the programs, the study suggests, is the best way to recycle the containers.

But it’s not that simple.

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Jumat, 11 Desember 2009

Waste Management - Excellent Strategy

Waste Management is the largest garbage hauler and landfill operator in North America. This blog previously relayed the announcement that over the next 5 years WM plans to invest approximately $400 million to convert landfill gas to electricity. We now learn from Green Car Congress that this forward-looking company plans to do something more with the methane retrieved from landfill gas than combustion in gas turbines to produce electricity. Waste Management of Seattle has introduced the first of 106 new CNG waste collection trucks for its fleet.
Generally I am pro bio-gas, given that the optimized diversion of manure to bio-gas production by means of anaerobic digestion results in a negative value for production and is the only alternative fuel to do so in the Zah study. On the other hand, I have been cautious about endorsing the use of LFG (Land Fill Gas). Likewise, I have been critical of powering vehicles with CNG (Compressed Natural Gas).


Bio-gas, a.k.a., renewable natural gas, is a versatile energy source. Anaerobic digestion is a way to process manure that can reduce odor and water quality issues.

Nevertheless, with the double jeopardy of climate change and peak oil, it would seem that WM has a winner if it can ensure clean, efficient means of producing such fuels and ensuring that there combustion produces very low amounts of GHG emissions. How much of a winner then will depend upon future federal incentives and the cost of petroleum. If oil prices remain unexpectedly low and federal incentives withheld, then WM might forestall development since bio-gas is in the middle of the pack in terms of cost, efficiency, import dependency, fuel price sensitivity and proved reserves. While such scenarios are possible, it is much more likely than oil prices will rebound and there will be federal incentives consistent with IPCC recommendations for which Waste Management qualifies.
WM operates 281 landfills in North America; 100 already have some form of methane-to-energy capabilities; and, last June plans were announced for landfill gas-to-energy facilities at 60 additional sites. If the sooner that oil prices rebound, the greater the economic incentive for WM to invest in multi-step upgrading of land fill gas.



According to the Environmental Protection Agency, landfills are the largest source of methane emissions in the United States, accounting for 34 per cent of such releases. Methane is one of several non-CO2 gases that contribute to global climate change and chemically 20 times more hazardous that carbon dioxide

The trucks use Autocar chassis and McNeilus (an Oshkosh Corporation) bodies. McNeilus expects to deliver the remaining CNG vehicles to Seattle in late March 2009. McNeilus is also providing 40 CNG refuse trucks to Cleanscapes, the other contractor for refuse collection in Seattle under recently awarded contracts.
Waste Management is putting the new trucks into service as they arrive and has a dozen already on the job in Seattle. The full complement of 106 CNG trucks will be in service when Waste Management begins its new collection contract with the city of Seattle on 30 March. Construction on the fueling depot is scheduled to be complete in April. The station will service the new fleet and also be open to the public.
Waste Management is investing $29 million in the new vehicles and an additional $7.5 million to build the fueling station. The new trucks are six times cleaner than diesel engines manufactured in 2007 and meet the US Environmental Protection Agency (EPA) 2010 emission standards for oxides of nitrogen (NOx) and PM.
An independent environmental review produced by Gladstein, Neandross & Associates, a environmental consulting firm, determined Waste Management’s equipment upgrade will reduce smog-causing NOx by 97 percent, toxic diesel particulate matter by 94% and greenhouse gas by 20%, over current levels. Switching to advanced CNG vehicle operations will provide significant environmental, public health and community benefits to the region. The collection trucks also will reduce noise pollution.
Within five years all 180-collection trucks in Waste Management’s Seattle-based fleet will be fueled by CNG.
Background. Waste Management (WM) has been providing services under contract with Seattle Public Utilities (SPU) for twenty years. The other waste collection provider under the current set of contracts, which end in March 2009, is Allied Waste, Inc. Following a number of problems with Allied Waste, SPU issued a Request for Proposals (RFP) for solid waste collection and transfer services across four geographic sectors, rather than the current two, in February 2007. Waste Management, Allied Waste and Seattle-based newcomer CleanScapes submitted proposals; SPU chose WM and Cleanscapes.
The 10-year contracts required CleanScapes and Waste Management to purchase all new collection trucks before beginning service in April 2009. All collection trucks are required to meet 2007 Federal Diesel Engine Requirements or to operate on CNG or LNG. Waste Management runs its current collection fleet on diesel. Both WM and Cleanscapes are using CNG under the new contract.

Image credit: Environment Ministry Of Canada, Quebec
At its South Seattle operations headquarters Waste Management of Seattle broke wind ground on its new compressed natural gas (CNG) fueling station.
By developing WM also prepares for future eventualities. Upgraded bio-gas can be used to generate electric power that could be used on site, for grid-able hybrid vehicles (to include bio-gas range extended electric vehicles, and sold. Even though there are greater efficiencies to using electric drive, plus heat recovery sent back to gas conditioning and anaerobic digestion processes, much depends upon the cost of batteries. Although a less ubiquitous infrastructure than the Grid, connection to the natural gas infrastructure is another strategic advantage to bio-gas development.
…rise in the use of landfill gas can be attributed to a variety of factors. Higher energy prices make landfill gas cost-competitive, especially compared to other sources of renewable energy. Second, utilities are looking for new sources of renewable energy to meet renewable portfolio standards, and landfill gas is especially valuable to them because it provides base load power. There’s also a real demand from consumers for greener energy and many of them are taking part in voluntary programs and are willing to pay more for power derived from renewable sources.

Wes Muir, Director of Communications for Waste Management, Inc,

Other AG Posts Possibly Related :
• First of Its Kind
• Bio-gas Pros… and Cons
• A Tip for Town Managers / Supervisors
• Another Plug-in Hybrid Retrofit Kit

Kamis, 10 Desember 2009

Biogases - Alternative energy sources

The term "biogases" refers to gases created by the anaerobic fermentation of biological materials. Their main constituents are methane and carbon dioxide.
Considerable quantities of biogases are produced by :
• anaerobic fermentation of agricultural and organic waste (biogas),
• sludge digestion in the tanks of sewage treatment plants (sewage gas),
• organic residues in garbage tips (landfill gas).

Biogas



Disposal and treatment of biological waste represent a major challenge for the waste industry. For a wide range of organic substances from agriculture, foodstuff or feed industries, anaerobic fermentation is a superior alternative to composting.
Biogas - a mixture of methane and carbon dioxide - is created during anaerobic fermentation and serves as a high-energy fuel that can be used as a substitute for fossil fuels. Biogas-fueled gas engines improve waste management while maximizing the use of an economical energy supply.
Biogas results from anaerobic fermentation of organic materials. As a metabolic product of the participating methane bacteria, the prerequisites for its production are a lack of oxygen, a pH value from 6.5 to 7.5 and a constant temperature of 15 to 25°C (psychrophile), 25 to 45°C (mesophile) or 45 to 55°C (thermophile). The fermentation period is approximately 10 days for thermophiles, 25 to 30 days for mesophiles and 90 to 120 days for psychrophile bacteria. The fermentation systems of today operate largely within the mesophile temperature range.

Sewage Gas



The anaerobic digestion of sewage sludge involves fermenting the sludge in tanks at a temperature of 90 to 93 °F (32 to 34 °C) for about 25 days. The thermal energy generated by a combined heat and power (CHP) unit preheats the sludge and keeps the temperature of the digestion tank constant.
The resulting biogas normally consists of 50 to 60 percent methane, 30 to 40 percent carbon dioxide and small quantities of residues. The gas is compressed and purified if it contains larger amounts of contaminants, and stored temporarily in a gasometer from which it is fed to a CHP unit at constant pressure. A gas engine transforms the energy stored in the biogas into mechanical and thermal energy. It also powers a synchronous generator, which in turn generates electrical energy for the operation of the sewage treatment plant.

Landfill Gas - Producing Usable Energy from Garbage



Landfill gas is created during the decomposition of organic substances and consists of methane (CH4), carbon dioxide (CO2) and nitrogen (N2). Uncontrolled venting of landfill gas hampers or prevents rapid, scheduled recultivation of a landfill site. To prevent this and to avoid offensive smells, smouldering fires or the migration of gas, the gas must be continuously extracted under controlled conditions. With a calorific value of about 5 kWh/m3N, landfill gas constitutes a high-value fuel for gas engines that can be effectively used for power generation.

Landfill gas is an alternative form of fuel to fossil fuels in the production of electricity. With landfill sites all over the UK, there is a large resource available.
Landfill Gas (LFG) is the product of the degradation of biodegradable waste and it is typically made up of about 50% methane (although this can reach about 65%), with the remainder mainly carbon dioxide plus small amounts of other gases. Both methane and carbon dioxide are ‘greenhouse gases’ contributing to global warming, so their use in this case as fuel reduces their release into the atmosphere. LFG is also a danger to the local environment causing problems for local vegetation, potential fires and explosions and even asphyxiation if released into a building.



Under optimum conditions one tonne of biodegradable waste can produce between 200 and 400 cubic metres of landfill gas. Due to the use of greenhouse gases and the fact that this energy source displaces the use of fossil fuels, landfill gas is deemed to be a ‘green energy’. The landfill gas is extracted from the site and burnt in order to produce electricity. Currently, 48% of Great Britain’s renewable gas and electricity production comes from landfill gas.
Landfill gas can also be used for direct firing (e.g. in brick kilns or for producing steam in boilers) or for direct heating (e.g. in horticultural greenhouses). Again, this reduces the amount of gas released into the atmosphere and can provide an income stream once the landfill site is full.

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Landfill Gas Capture

Methane is a primary component of landfill gas and a potent greenhouse gas when released to the atmosphere. 20 times more damaging than CO2. Reducing methane emissions by capturing landfill gas and using it as an energy source can yield substantial energy, economic, and environmental benefits. Each day millions of tons of municipal solid waste are disposed of in landfills around the world. landfill gas is created as a natural byproduct of decomposing organic matter, such as food and paper, disposed of in these landfills. landfill gas consists of about 50 percent methane (CH4), the primary component of natural gas, about 50 percent carbon dioxide (CO2), and a trace amount of non-methane organic compounds. Globally, landfills are the third largest anthropogenic (human-induced) emission source, accounting for about 12 percent of global methane emissions or nearly 750 million metric tons of CO2 equivalent (MMTCO2E). Below is a chart of world landfill gas production by country as of 2007.


Figure 1: World Landfill Gas Production By Country As Of 2007


Figure 2 : World Landfill Gas Production By Country As Of 2007

Recycling Waste

The chemical industry continues to find creative ways of recycling and reusing waste streams. Dow recently began operating a novel system for reusing municipal wastewater at the Terneuzen site in the Nether-lands. In collaboration with local authorities and a local water pro-ducer, this site accepts more than 2.6 million gallons of municipal household wastewater every day. The local water producer removes residual contaminants, and Dow then uses more than 70 percent of this water to generate high-pressure steam. After the steam is used in production processes, the water is again used in cooling towers until it finally evaporates into the atmosphere.
This is the first time municipal wastewater is being reused on such a large scale in the industry. Three million tons of water per year was previously discharged into the North Sea after a single use. Now this water is recycled for two more applications and has resulted in 65 percent less energy use at this facility compared to the alternative option of desalinating seawater. The reduction in energy use is the equivalent of lowering carbon dioxide emissions by 5,000 tons per year. This concept can be applied at other locations around the world.
Another unique case of recycling is the use of landfill off-gas (Figure 2). Instead of using natural gas, Dow has piped methane off-gas from a local landfill to its Dalton, Georgia, latex manufacturing plant. The gas is used as fuel to generate steam for the production of latex carpet backing. This site is expected to use approximately 160 billion BTUs per year of landfill gas (the energy equivalent of 1.4 million gallons of gasoline) that would otherwise be emitted into the atmosphere.


FIGURE 3 : Recycling landfill off-gas for energy in Dalton, Georgia.
(1) Landfill waste is structured. (2) Anaerobic bacteria decompose the municipal solid waste. (3) Methane off-gas is generated. (4) A system of pipes and blowers collects gas and delivers it to a central location. (5) Gas is used as fuel to make steam. (6) Steam is used by the Dow emulsion polymers plant to manufacture latex carpet backing.

Municipal landfills are the largest source of human-generated methane emissions in the United States. As a greenhouse gas, methane has more than 20 times as much global warming potential as carbon dioxide. By capturing and burning methane, the Dalton facility will reduce the use of fossil fuels and will reduce methane emissions from the landfill. The reduction of greenhouse gases is equivalent to 24 million pounds of carbon dioxide per year.

Landfill Gas

Produced by the biological decomposition of waste placed in a landfill site, LFG represents both an environmental liability and a unique renewable energy resource. Landfill gas - composed primarily of carbon dioxide and methane - also commonly contains additional trace constituents such as hydrogen sulphide, mercaptans, vinyl chloride, and numerous other volatile organic compounds. Concerns that are often associated with LFG relate to odours, air quality impacts and explosion hazards. If released to the atmosphere untreated, LFG is also a potent greenhouse gas contributing to global climate change. Collection of LFG to control impacts also results in the creation of a source of green energy. The methane component of LFG contains energy that can be used to generate electricity, heat buildings, fuel industrial processes, or run vehicles. Utilization of energy from LFG not only aids in the control of local environmental impacts, but also avoids consumption of fossil fuels that would otherwise be required to generate an equal amount of energy. Collection and utilization of LFG represents a very significant opportunity to reduce greenhouse gas emissions to the atmosphere.


Figure 4: Landfill Gas Collection & Utilization System

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