Showing posts with label alternative. Show all posts
Showing posts with label alternative. Show all posts

November 15, 2012

Fuel From Waste, Poised at a Milestone


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posted by Milton
http://www.nytimes.com/2012/11/14/business/energy-environment/alternative-fuels-long-delayed-promise-might-be-near-fruition.html?pagewanted=2&_r=0
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Ken Childress for KiOR
Pine trees being prepared for conversion into cellulosic gasoline and diesel fuels at KiOR’s Columbus, Miss., plant. The company has lined up three buyers.
WASHINGTON — For years, scientists and engineers have been juggling various combinations of acids, steam, bacteria, catalysts and the digestive juices of microorganisms to convert agricultural waste and even household garbage into motor fuel.
Green
A blog about energy and the environment.
John Van Beekum for The New York Times
The $130 million Ineos plant in Vero Beach, Fla., where wood and woody garbage will be broken down and converted into ethanol.
So far, such alternative fuels have not moved beyond small pilot plants, despite federal incentives to encourage companies to develop them.
But that could be about to change.
Officials at two companies that have built multimillion-dollar factories say they are very close to beginning large-scale, commercial production of these so-called cellulosic biofuels, and others are predicting success in the months to come.
In Columbus, Miss., KiOR has spent more than $200 million on a plant that is supposed to mix shredded wood waste with a patented catalyst, powdered to talcumlike consistency. Its process does in a few seconds what takes nature millions of years: removes the oxygen from the biomass and converts the other main ingredients, hydrogen and carbon, into molecules that can then be processed into gasoline and diesel fuel.
KiOR aims to turn out 13 million gallons of fuel a year and has already lined up three companies to buy its output, including FedEx and a joint venture of Weyerhauser andChevron. KiOR said on Thursday that it had begun producing what it called “renewable crude” and intended to refine that into gasoline and diesel that it would begin shipping by the end of the month.
And Ineos, a European oil and chemical company, is putting the final touches on a plant in Vero Beach, Fla., that would cook wood and woody garbage until they broke down into tiny molecules of hydrogen and carbon monoxide. Those molecules would be pumped into a giant steel tank, where bacteria would eat them and excrete ethanol. The company has spent $130 million on the plant, which is supposed to make eight million gallons a year, about 1 percent of Florida’s ethanol demand. The plant is next to a county landfill, and executives covet the incoming garbage.
Both plants are far smaller than typical oil refineries, but commercial production at either one — or at any of several of the plants that are a step behind them — would be a major milestone in renewable energy.
At such plants, the goal is sometimes to make ethanol and sometimes gasoline or diesel fuel or their ingredients. The pathways to make the biofuels are varied. But the feedstocks have something in common: they are derived from plants and trees, but not from food crops like corn kernels, which are the basis of most of the biofuel currently made in the United States.
Often, the raw ingredients for the cellulosic biofuels are the wastes of farms, paper mills or households, with a value that is low or even negative, meaning people will pay the fuel producers to dispose of them. And the companies developing the new fuels say that their products produce far fewer carbon emissions than petroleum-based gasoline and diesel.
KiOR says that its fuel will release one-sixth the amount of carbon dioxide as an equivalent amount of petroleum fuel. That is mostly because every tree or woody plant fed into its process will eventually be replaced by a new tree or plant, which will suck carbon dioxide out of the atmosphere. And a byproduct of its factory is surplus electricity, which will be exported to the grid, displacing electricity that would otherwise be generated from natural gas or coal.
Ineos goes a step further, saying its production process actually reduces the overall amount of carbon in the atmosphere. “We could make the argument that we’re carbon-negative,” said Peter Williams, the chief executive. The reason, he said, is that electricity produced from its plant averts emissions that would have come from other electricity sources.
Just becoming the first company to produce commercial volumes of these alternative biofuels is no guarantee of commercial success. That depends on further optimizing production processes to get more gallons of fuel per ton of raw materials at lower operating costs.
Industry officials say that profits also depend on continued high prices for oil, the commodity that biofuels would replace, and a continuation of a federal government mandate that requires fuel blenders to mix a certain percentage of biofuels into the gasoline sold at service stations.
“Sustainability requires good economics,” Mr. Williams said.
Many companies have produced biofuel successfully, but only in quantities characteristic of a factory that makes fine whisky or perhaps perfume. The trick is to get reliability up and costs down to a level that allows operation on a large scale.
Government policy has anticipated far more technical progress than the industry has made. Congress set a goal of 250 million gallons of cellulosic biofuel for 2011 and 500 million gallons for this year, but the Environmental Protection Agency cut the requirement to six million gallons for 2012 because of the lack of commercial production.
Six governors, oil refiners and companies hurt by high corn prices have asked the agency to waive its requirements for ethanol and other renewable fuels. Some single out the corn ethanol mandate, but others want the quota for cellulosic fuels waived, too, partly because there is no actual production.
The cellulosic biofuel industry has asked the E.P.A. to keep all the rules intact. Waiving the rule for corn ethanol would discourage investment in advanced biofuels as well, said Brent Erickson, a spokesman for BIO, a trade organization. “You can’t de-link them,” he said.
Green
A blog about energy and the environment.
The agency was expected to rule on Tuesday, but instead said it would rule “shortly.” To grant the waiver, it would have to find severe harm to the economy. Energy experts say that eventually renewable motor fuel could have a much bigger impact on the United States economy than renewable electricity from wind farms or solar cells. Renewable electricity saves coal and natural gas, which are cheap and domestically plentiful. Renewable motor fuel displaces oil, which is much more expensive and often imported, which poses a host of national security and trade issues.
If either Ineos or KiOR began commercial production, it would break a long string of overly optimistic promises made by the industry and the government.
In October 1998, for example, the Energy Department showed off a plant in Jennings, La., that made ethanol from sugar cane wastes; the department said it would reach commercial production within a few years. At the time the plant was owned by a government-subsidized firm called BC International, which was later reorganized and renamed Celunol. Then it was taken over by Verenium, which, with backing from BP, tried another method. BP announced on Oct. 25 that it was dropping plans for a commercial plant based on technology piloted at Jennings, although it still does research there.
Mascoma, based in Cambridge, Mass., and backed by General Motors and Khosla Ventures, among others, is trying to make ethanol from wood waste. Samir Kaul, a board member representing Khosla, confidently predicted in 2006 that it would be in commercial production by 2008, but that goal remains elusive.
Iogen, an established Canadian producer of enzymes, began producing ethanol from wheat straw in 2004, and said in the fall of 2005 that it hoped to announce plans for a commercial plant by the end of that year. Eventually, it announced plans for a plant in southern Manitoba, but in April of this year it dropped that idea, and laid off some workers at its Ottawa headquarters.
But new chemistry technology, like hope, springs eternal.
POET, a major producer of ethanol by conventional means, is building a plant in Emmetsburg, Iowa, that is supposed to digest 700 tons of corn cobs a day and feed the resulting sugars into a conventional ethanol plant next door. The goal of the project, which is supposed to be ready by late 2013, is to produce 20 million gallons of cellulosic ethanol a year.
Abengoa, a Spanish firm, has been running a pilot plant in Salamanca, Spain, and in June 2011, broke ground on a $350 million commercial plant in Hugoton, Kan., that is now 50 percent complete, according to Manuel Sanchez Ortega, the chief executive. It is currently slated to open in the third quarter of next year and is supposed to make 25 million gallons of ethanol a year from agricultural waste, wood waste and nonfood crops.
And a variety of smaller companies are a step behind.
The holy grail is to find a way to profitably make renewable fuels from otherwise wasted biomass, as opposed to valuable food crops.
“If we can do it with biomass, then there is no more discussion of food versus fuel; it’s over,” Mr. Ortega said.

Negative Impacts of Incineration-based Waste-to-Energy Technology


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posted by roz
http://www.alternative-energy-news.info/negative-impacts-waste-to-energy/
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September 8th, 2008 - View Comments
Waste Energy PollutionDespite being an attractive technological option for waste management, combustion-based processes for municipal solid waste (MSW) treatment are a subject of intense debate around the world. In the absence of effective controls, harmful pollutants may be emitted into the air, land and water which may influence human health and environment. Although incineration of municipal waste coupled with energy recovery can form an essential part of an integrated waste management system, yet strict controls are required to prevent its negative impacts on human health and environment.
Incineration technology is the controlled combustion of waste with the recovery of heat to produce steam that in turn produces power through steam turbines. MSW after pretreatment is fed to the boiler of suitable choice wherein high pressure steam is used to produce power through a steam turbine. Pyrolysis is extensively used in the petrochemical industry and can be applied to municipal waste treatment where organic waste is transformed into combustible gas and residues. Gasification is another alternative which normally operates at a higher temperature than pyrolysis in limited quantity of air. While both pyrolysis and gasification are feasible technologies to handle municipal waste, commercial applications of either technology have been limited.
Incineration-based technologies have been a subject of intense debate in the environmental, social and political circles. This article evaluates incineration on the basis of three parameters – environmental, human health and economic impact – and proposes an integrated mechanism to maintain a fine balance between energy recovery and environmental concerns.
Environmental Issues
The incineration process produces two types of ash. Bottom ash comes from the furnace and is mixed with slag, while fly ash comes from the stack and contains components that are more hazardous. In municipal waste incinerators, bottom ash is approximately 10% by volume and approximately 20 to 35% by weight of the solid waste input. Fly ash quantities are much lower, generally only a few percent of input. Emissions from incinerators can include heavy metals, dioxins and furans, which may be present in the waste gases, water or ash. Plastic and metals are the major source of the calorific value of the waste. The combustion of plastics, like polyvinyl chloride (PVC) gives rise to these highly toxic pollutants.
Toxics are created at various stages of such thermal technologies, and not only at the end of the stack. These can be created during the process, in the stack pipes, as residues in ash, scrubber water and filters, and in fact even in air plumes which leave the stack. There are no safe ways of avoiding their production or destroying them, and at best they can be trapped at extreme cost in sophisticated filters or in the ash. The ultimate release is unavoidable, and if trapped in ash or filters, these become hazardous wastes themselves.
The pollutants which are created, even if trapped, reside in filters and ash, which need special landfills for disposal. In case energy recovery is attempted, it requires heat exchangers which operate at temperatures which maximize dioxin production. If the gases are quenched, it goes against energy recovery. Such projects disperse incinerator ash throughout the environment which subsequently enter our food chain.
Incinerator technological intervention in the waste stream distorts waste management. Such systems rely on minimum guaranteed waste flows. It indirectly promotes continued waste generation while hindering waste prevention, reuse, composting, recycling, and recycling-based community economic development. It costs cities and municipalities more and provides fewer jobs than comprehensive recycling and composting and also hinders the development of local recycling-based businesses.
Human Health Concerns
Waste incineration systems produce a wide variety of pollutants which are detrimental to human health. Such systems are expensive and does not eliminate or adequately control the toxic emissions from chemically complex MSW. Even new incinerators release toxic metals, dioxins, and acid gases. Far from eliminating the need for a landfill, waste incinerator systems produce toxic ash and other residues.
The waste-to-energy program to maximize energy recovery is technologically incompatible with reducing dioxins emissions. Dioxins are the most lethal Persistent Organic Pollutants (POPs) which have irreparable environmental health consequences. The affected populace includes those living near the incinerator as well as those living in the broader region. People are exposed to toxics compounds in several ways:
* By breathing the air which affects both workers in the plant and people who live nearby;
* By eating locally produced foods or water that have been contaminated by air pollutants from the incinerator; and
* By eating fish or wildlife that have been contaminated by the air emissions.
Dioxin is a highly toxic compound which may cause cancer and neurological damage, and disrupt reproductive systems, thyroid systems, respiratory systems etc.
Financial Impacts
All over the developed world, almost half the investment is put in control systems to reduce toxic emissions such as mercury, cadmium, lead, dioxins, furans, volatile organic compounds etc. For example a 2000 MT per day incinerator can cost upwards of $500 million in Europe, half of the cost being put into emission control. Another problem arises in the case of developing countries because the average calorific value garbage in such countries is about 800 cal / kg. For combustion technologies to succeed they would need about 2000 to 3000 cal / kg, other wise auxiliary fuel has to be added. This makes the process more uneconomical and polluting than it already is.
Most of the size and expense of the incinerator is dedicated to the pollution control equipment. The first component of the pollution control equipment is the stage at which ammonia is injected into the gases produced from the burning process which assists in the removal of NOx. The removal of mercury is achieved by the injection of activated carbon. Lime is then injected in the dry scrubber stage whereby the acid gases are removed. Further, most incinerators have a bag-house or electrostatic precipitator to facilitate the capture of particulate and toxics. Thus, it can be realized that the cost of the pollution control system over-rides the cost of the incinerator by a huge margin.
Incineration experts generally state that to have an economically viable operation, it is required to have an incinerator that burns at least 1000 tonnes of garbage each day. The cost to build such a facility is approximately $100 million. Operating costs to maintain the equipment, especially the pollution control equipment is also high.
It is dangerous to bury fly ash in a regular municipal landfill. A special hazardous waste landfill is required which is almost ten times costlier than a municipal landfill. Therefore, the cost of municipal waste incineration shoots up due to the requirement of a special landfill for fly ash disposal.
Conclusions
The adoption of alternative cleaner methods for the disposal of municipal garbage is necessary. According to the United Nations Environment Programme (UNEP), incinerators are the leading source of dioxin into the global environment. The EPA, in a recent study, identified dioxins as the cause of many cancers, the worst component being TCDD (also known as Agent Orange).
The need for low-cost solutions presents significant difficulties, but it is not an impossible task. The ideal resource management strategy for MSW is to avoid its generation in the first place. In 1993, a Royal Commission on Environmental Pollution in England issued a four-stage decision procedure of which the first two stages state:
* Wherever possible, avoid creating wastes,
* Where wastes are unavoidable, recycle them if possible.
This implies changing production and consumption patterns to eliminate the use of disposable, non-reusable, non-returnable products and packaging.
An integrated solid waste management (ISWM) is essential to establish a waste hierarchy to identify the key elements. The general hierarchy should be comprised of the following order:
1. Reduce
2. Reuse
3. Recycle
4. Waste minimization and recovery of energy from waste by composting, anaerobic digestion, incineration etc.
5. Landfilling
The cost of building and operating incinerators or providing special landfill sites is enormous. If substantial parts of these funds were to be diverted towards waste minimisation and encouraging recycling, the need for waste disposal could be enormously reduced, apart from reducing the dangers which arise from both incineration and landfill. It is essential to explore the potential of environment-friendly technologies, like anaerobic digestion (AD), for the treatment of municipal waste because it holds the promise to address two highly important environmental concerns – waste management and renewable energy.
Written by Salman Zafar, Renewable Energy Expert.