Enhancing Gas Extraction and Pre-treatment for Landfills

Presentation by Graeme Alford, CEO, LGP

Our Vision: “To be the most efficient & innovative global provider of Renewable Energy.”

Slide 1: The earth is coping with a crisis.  The effect of technology within the industrialised world has resulted in greenhouse gas emission levels that are damaging the earth and threatening our way of life.  Global warming will affect all of us if changes are not made to the amount of CO2 being put into the atmosphere.

Slide 2: The amount of CO2 in the atmosphere is currently at 380 parts per million being about 25% above the previously highest level of 300ppm.  During the past 650,000 years, measured from ice core samples, the CO2 concentration has ranged between 180 and 300ppm.  The concentration is now increasing at the rate of 20ppm per decade. 

Temperature projections indicate an increase of 0.5 and 1.5oC by 2030 and between 1 and 5oC by 2070.  Some say a 2oC change is irreversible

Slide 3: Total Australian CO2 emissions in 2004 were 565Mt of which waste contributed 3%.  The majority is from stationary electricity generation.  The capture of methane created from the breakdown of the rubbish in our landfills and its controlled burning will be up to 23 times less damaging than letting the gas escape into the atmosphere.

Slide 4: In many cases there will be an environmental landfill operational licence requiring the capture of landfill gas and its combustion on the larger or more recently constructed sites.

The WA State Government is presently looking at making more landfill operators collect and destroy the methane generated from their sites.

Slide 5: With the larger landfills, this process will result in the generation of green electricity and the possibility of a royalty payable to the landfill owner from the contractor operating the facility. 

Slide 6: In our opinion, we believe the landfill would need to service a population of 150,000 people before the generation of electricity would become economically viable. 

For smaller sites, it may be possible to generate some electricity for internal use only or to flare the gas, thereby reducing its environmental effect.

Slide 7: The landfill gas capture system will be the same irrespective of the method of burning of the gas.  It comprises the installation of a series of wells on a grid layout to collect the gas.

Slide 8: The design of the grid is determined by:

• landfill characteristics such as waste type, compaction rates
• surface area of the landfill,
• depth of waste,
• surface slopes, and
• type of final cover provided by the operator.

Slide 9: These wells are connected by pipes to the collecting manifold, which delivers the gas to power the station via a vacuum pump.  The well field operates under a slightly negative pressure to draw the gas out.

Slide 10: Gas delivered to the power station has to be prepared for consumption in engines modified for landfill gas combustion.  These processes will vary depending on the contractor as each has developed their own expertise from operating these plants over many years. 

This is where a competitive advantage can be gained and thus the intellectual property involved is closely guarded.

Slide 11: The engine/genset is located without an acoustic module within the power station building to minimise noise to the surrounding land uses.  Likewise, the roof top mufflers are designed to minimise noise escaping from the site as the power station operates 24 hours per day.

Slide 12: In the longer term, the gas supply will progressively decline over time and will reach a point where there is insufficient gas for the generation of electricity.  At this time, the power station is removed and any remaining gas flared.

Generally, electricity can be generated for up to 20 years post closure of the landfill.

Slide 13: Power station operations can be monitored from a remote central location and thus the stations can be down the street, in another state or even another country.  On site personnel are required to attend to well field monitoring and undertake routine maintenance works.

I would now like to discuss what the federal government is doing to assist the renewable energy industry in Australia. 

Slide 14: The Australian Federal Government has set its targets under the Mandatory Renewable Energy Target (MRET) through until 2020 and is now looking for further gains from technological advances.  The MRET target is to increase renewable generation capacity from 300GWh in 2001 to 9,500GWh by 2010 and to maintain this level until 2020

In 2004, the Australian Federal Government created the $500 million Low Emissions Technology Development Fund and has funded a number of projects thus far.

Slide 15: As at December 2005, more than 15 million Renewable Energy Certificates (RECs) had been created from 229 accredited power stations.  Landfill gas contributed 1.3 million RECs or 8% to this total.  The 2006 report is due out anytime.

Slide 16: In June 2007, the Prime Minister, Mr John Howard, announced Australia would be getting an Emissions Trading Scheme to start in 2011 or 2012.  This would cover electricity generation and transport industries, but initially excludes the waste industry.  It would be a cap and trade scheme.
In May 2007, the Premier’s Climate Change Action Statement, titled “Making Decisions for the Future: Climate Change” was the release.  I will now discuss several of the key points relating to renewable energy.

The key factors are:

• 15% renewable by 2020 and 20% by 2025.
• 20% of Government electricity is to be from renewable sources by 2010.
• Low Emissions Energy Development Fund (LEED).  $36.5m for low emission energy demonstration projects.  Will provide much needed financial support to these types off projects
• Capturing Greenhouse gas emissions from landfill sites. (up to 19 million tonnes of CO2 equivalent or 2.5 per cent of WA’s total emissions are omitted from landfills)

Slide 17: Our planet is changing as a result of human activity.  The level of awareness around this issue is changing and it is now becoming a major political issue as both major political parties have included in their policies for the forthcoming federal election. 

Action is required now to reverse the trends and to ensure the long term viability of the planet and the lifestyles that we enjoy.

Slide 18: Landfill operators have an obligation to operate their landfills in an environmentally sustainable manner.  One key aspect is the collection and proper disposal of the landfill methane gas generated.

The generation of electricity from landfill gas, in addition to minimising the environmental effects of the gas generated by the landfill, is producing green electricity and is therefore offsetting the need for additional black electricity generated from fossil fuel products.  It therefore has a compounding benefit for our community and the environment.