Archive for noviembre, 2012

Reducción del coste de tratamiento de aguas residuales

An award-winning ABB medium voltage drive has reduced the energy consumption of the aeration blowers at a US wastewater treatment plant by more than 1 million kilowatt-hours a year – a reduction of more than 30 percent that saves the city utility $75,000 annually.

By ABB Communications

The aeration basins (left) and aeration blower system (right) at the City of Beloit Water Pollution Control Facility, Wisconsin

The ACS 2000 medium voltage variable speed drive was installed in July 2011 and has achieved some remarkable results within its first year of operation at the City of Beloit Water Pollution Control Facility (WPCF) in Wisconsin, United States.

The facility treats an average of 5.5 million gallons (20.8 million liters) of wastewater a day from the city’s 37,000 inhabitants, as well as industrial waste from local businesses and biological waste from food processing plants.

Like many wastewater treatment plants, Beloit uses a conventional activated sludge process for treating the wastewater. At the heart of this process are the aeration basins in which microorganisms break down the organic matter in the wastewater. These bacteria require oxygen to survive, which is provided by huge aeration blowers that blow air through diffusers at the bottom of the basin.

ACS 2000
Winner of the 2010 Frost & Sullivan European Medium Voltage Drives
New Product Innovation Award

Aeration blowers typically account for 50 percent or more of the electricity consumed by a wastewater treatment plant, and Beloit is no exception. Prior to the installation of the ACS 2000, the aeration blower system at Beloit WPCF was controlled by an inlet throttling valve – a common solution for blower control that operates at fixed speed and does not offer the same operating and cost benefits as variable speed drives.

For Beloit WPCF these benefits are wide-ranging and include soft start capability, ease of installation, direct-to line (transformerless) connection to the power supply network, minimal harmonic distortion, non-requirement of medium voltage power factor correction, compact and lightweight footprint, short payback time and low total cost of ownership.

These benefits are enhanced by an ABB DriveMonitor™ intelligent diagnostic system that performs remote and real-time monitoring and diagnostics of the drive via a wall-mounted PC connected to the telephone line.

Once the ACS 2000, was installed the power consumption of the aeration blower system dropped by more than 30 percent and total plant energy consumption by 15 percent, which is more than 1 million kilowatt-hours a year. At an average composite rate of $0.62/kWh, the annual savings for the City of Beloit amount to $75,000.


2 de noviembre de 2012 at 10:11 Deja un comentario

Suecia compra a Noruega la basura para cumplir con sus necesidades energéticas

Sweden started buying trash from Norway in order to meet its ongoing energy needs. The nation is extremely efficient at managing its refuse and no longer has sufficient waste to incinerate.

Sweden now imports roughly 800,000 tons of trash, most of it from Norway. According to PRI, “it’s more expensive to burn the trash there and cheaper for the Norwegians to simply export their waste to Sweden. […] In the arrangement, Norway pays Sweden to take the waste off their hands and Sweden also gets electricity and heat.” Any toxic ash, such as the ash containing heavy metals, is returned to Norway for disposal.

Avfall Sverige, or Swedish Waste Management, estimates (link is PDF) each person in the nation generates a half ton of waste annually. An estimated 4% of Sweden’s household waste is sent to landfills while the remainder is either recycled or fuels waste-to-energy power plants, according to the agency. In the United States, in 2010, 250 million tons of trash was generated, and of that about 34% was recycled, estimates NPR.

Overtornea heat power plant

Waste-to-energy plants supply 20% of Sweden’s district heating. District heating is a heat distribution system that uses heated water piped into residential and commercial buildings. The system also provides electricity for a quarter of a million homes.

Avfall Sverige reports state that national incineration capacity has trebled and energy production has increased five-fold since the mid-1980s as emissions have been reduced in by almost 99%.

The average amount of trash generated in Europe sent to landfills is about 38%. Sweden stands at 1%, according to Eurostat.

Waste-to-energy can meet a great deal of Europe’s annual heating needs, according to the organization:

[A]round 50 million tons of waste are processed through incineration every year throughout Europe. This corresponds to the heat requirements for the populations of Sweden, Norway, Iceland, Finland, Denmark, Estonia, Latvia and Lithuania. In Sweden alone, waste incineration generates as much energy as 1.1 million cubic metres (m³) of oil, which reduces carbon dioxide (CO2) emissions by 2.2 million tons per year. This is as much CO2 as 680,000 petrol-powered cars emit in a year.

Catarina Ostlund, Senior Advisor for the Swedish Environmental Protection Agency, told PRI that Sweden is producing very little waste and cannot meet its needs for heating. She says that the nation still needs to reduce its waste output.

She said the arrangement with Norway is merely a stopgap:

This is not a long-term solution really, because we need to be better to reuse and recycle, but in the short perspective I think it’s quite a good solution. […] I hope that we instead will get the waste from Italy or from Romania or Bulgaria or the Baltic countries because they landfill a lot in these countries. They don’t have any incineration plants or recycling plants, so they need to find a solution for their waste.

Sweden began implementing its waste-to-energy system after World War II.

Avfall Sverige was founded in 1947 and is a 400-member association consisting primarily of muncipalities with about a fourth of its membership from the corporate sector.

2 de noviembre de 2012 at 10:07 Deja un comentario

Nuevo Biocombustible de paja


Nuevo biocombustible, de paja → etanol biocombustibles peroleo petroleo de paja paja


BP Finaliza el plan para construir una Planta de Biocombustible
British Petroleum, (BP) el jueves canceló los planes para construir una plataforma en Florida para convertir plantas resistentes como la caña en biocombustible. BP es la segunda compañía de petróleo más grande del mundo y quiere producir la”próxima generación” de etanol a partir de cultivos no alimentarios.

Los biocombustibles se han convertido en un problema político ya que las empresas luchan para producir cantidades comerciales y cumplir con un mandato político.

BP dijo que ahora prevé centrarse en la investigación y el desarrollo, así como las licencias de su tecnología de biocombustibles, en lugar de construir la planta de 36 millones de dólares con plantas que sirven para alimentarse.

“Dada la gran cartera y crecientes oportunidades de inversión disponibles de BP a nivel mundial, creemos que el interés de nuestros accionistas en futuras inversiones ha hecho que se cancele la construcción de la planta e invertir mejor en un futuro en mejores biocombustibles y en otros proyectos más atractivos”, dijo Geoff Morrell, presidente de la compañía, en los medios de comunicación.

En abril, la Royal Dutch Shell y Iogen desecharon los planes de construir una planta a escala comercial en Canadá para producir etanol a partir de residuos de paja y plantas.

Después de haber arrasado bosques para producir biocombustibles, al fin se han dado cuenta que biocombustibles, sí, pero no a costa de la pobreza de muchos ciudadanos que han dejado de tener alimento ya que hayan arrasado la vegetación, provocando así la desaparición de los animales que de ella depende.

2 de noviembre de 2012 at 10:03 Deja un comentario

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