Americans Turn Waste into Energy in Grand Rapids
Americans produce a lot of waste. Some of it gets thrown in the kitchen garbage can or hauled to the dump, while some of it gets flushed down the toilet or sent down the garbage disposal.
Like the stuff you throw in your garbage can, a lot of the solids in our wastewater stream eventually end up in the landfill where they emit greenhouse gasses and contribute to climate change.
However, in Grand Rapids, the city’s wastewater treatment plant takes the organic matter that comes through its sewage system and turns it into something useful: energy.
The Rapid Converts Buses to Compressed Natural Gas
The Rapid, the transit system that runs buses around Grand Rapids and its suburbs, has started converting buses over to engines that could run on compressed natural gas.
Steve Schipper, chief operating officer for the Rapid, said the move away from diesel was both environmentally and financially motivated. Natural gas produces fewer emissions and is less susceptible to huge price swings.
The Rapid has been driving on natural gas purchased from DTE for a while now. Now, some of that natural gas will be coming from the city’s sewage.
How Does It Work?
The Water Resource Recovery Facility is where everything that gets flushed down a Grand Rapids toilet or garbage disposal ends up.
Jared Grabinski, assistant environmental services manager at the facility, has played a big role in bringing the city’s $85 million biodigester online. A biodigester is a system that turns waste into a form of compressed natural gas.
Before the solid waste reaches the biodigesters, there is a series of processes to separate the waste they want from the waste they don’t.
- The first part of the physical process involves separating larger items using rotating screens.
- Next, the velocity of the water is slowed down to allow heavier materials to settle out.
- The water then goes through a phase of treatment where slow-moving bars skim oils or scum off the surface.
- The remaining water goes through biological treatment, where microorganisms break down organic material.
- The water is then separated and sanitized before being sent back to the Grand River.
The organic material mixed in with the water is used to create “mixed liquor” which is then fed into the biodigesters.
The Biodigesters
Biodigesters are three gigantic cylinders on the property that hold 1.4 million gallons each.
Inside the biodigester, microorganisms digest the organic material and produce biogas, which consists of methane gas and carbon dioxide.
The biodigester captures the biogas instead of sending it to a landfill, and it goes through a series of processes to convert it into pure methane. The city can then sell this methane to DTE.
How Methane Is Filtered Out
The biogas mix goes through a triple membrane system to remove impurities such as condensation, siloxane VOCs, and CO2. Screens monitor every step of the process to ensure efficiency and quality.
Once the gas is cleaned and chemically identical to compressed natural gas from other sources, it is fed into a DTE pipeline. This gas can then be used to power the buses.
Residents like Uriah Thompson, who uses the bus for his daily commute, appreciate the environmentally friendly approach. Thompson says, “I know the Earth is being polluted every day. Every day. So I’m fine with the natural way.”
SDGs, Targets, and Indicators
SDGs:
- SDG 7: Affordable and Clean Energy
- SDG 9: Industry, Innovation, and Infrastructure
- SDG 11: Sustainable Cities and Communities
- SDG 12: Responsible Consumption and Production
- SDG 13: Climate Action
Targets:
- SDG 7.2: Increase substantially the share of renewable energy in the global energy mix
- SDG 9.4: Upgrade infrastructure and retrofit industries to make them sustainable
- SDG 11.6: Reduce the adverse per capita environmental impact of cities, including by paying special attention to air quality and municipal and other waste management
- SDG 12.4: By 2020, achieve the environmentally sound management of chemicals and all wastes throughout their life cycle, in accordance with agreed international frameworks, and significantly reduce their release to air, water, and soil in order to minimize their adverse impacts on human health and the environment
- SDG 13.2: Integrate climate change measures into national policies, strategies, and planning
Indicators:
- Indicator for SDG 7.2: Share of renewable energy in the total final energy consumption
- Indicator for SDG 9.4: CO2 emissions per unit of value added
- Indicator for SDG 11.6: Annual mean levels of fine particulate matter (e.g. PM2.5 and PM10) in cities
- Indicator for SDG 12.4: Hazardous waste generated per capita and proportion of hazardous waste treated, by type of treatment
- Indicator for SDG 13.2: Number of countries that have communicated the strengthening of institutional, systemic, and individual capacity-building to implement adaptation, mitigation, and technology transfer
Analysis:
1. Which SDGs are addressed or connected to the issues highlighted in the article?
The issues highlighted in the article are connected to the following SDGs:
- SDG 7: Affordable and Clean Energy – The article discusses the conversion of buses to engines that run on compressed natural gas, which is a cleaner and more sustainable energy source.
- SDG 9: Industry, Innovation, and Infrastructure – The article mentions the upgrade of infrastructure, specifically the wastewater treatment plant, to turn waste into energy.
- SDG 11: Sustainable Cities and Communities – The article highlights the sustainable practices in Grand Rapids, such as using wastewater to produce energy and reducing emissions from buses.
- SDG 12: Responsible Consumption and Production – The article discusses the environmentally sound management of waste and the conversion of organic matter into energy instead of sending it to landfills.
- SDG 13: Climate Action – The article mentions the reduction of greenhouse gas emissions through the use of compressed natural gas and the capture of biogas from the biodigester.
2. What specific targets under those SDGs can be identified based on the article’s content?
The specific targets identified based on the article’s content are:
- SDG 7.2: Increase substantially the share of renewable energy in the global energy mix – The conversion of buses to engines that run on compressed natural gas contributes to increasing the share of renewable energy.
- SDG 9.4: Upgrade infrastructure and retrofit industries to make them sustainable – The upgrade of the wastewater treatment plant to turn waste into energy aligns with this target.
- SDG 11.6: Reduce the adverse per capita environmental impact of cities, including by paying special attention to air quality and municipal and other waste management – The use of compressed natural gas and the reduction of emissions from buses contribute to reducing the environmental impact of cities.
- SDG 12.4: By 2020, achieve the environmentally sound management of chemicals and all wastes throughout their life cycle, in accordance with agreed international frameworks, and significantly reduce their release to air, water, and soil in order to minimize their adverse impacts on human health and the environment – The conversion of waste into energy and the reduction of emissions contribute to achieving environmentally sound waste management.
- SDG 13.2: Integrate climate change measures into national policies, strategies, and planning – The reduction of greenhouse gas emissions and the use of renewable energy align with this target.
3. Are there any indicators mentioned or implied in the article that can be used to measure progress towards the identified targets?
There are indicators mentioned or implied in the article that can be used to measure progress towards the identified targets:
- Indicator for SDG 7.2: Share of renewable energy in the total final energy consumption – The conversion of buses to engines that run on compressed natural gas contributes to increasing the share of renewable energy.
- Indicator for SDG 9.4: CO2 emissions per unit of value added – The reduction of emissions from buses and the use of compressed natural gas contribute to reducing CO2 emissions.
- Indicator for SDG 11.6: Annual mean levels of fine particulate matter (e.g. PM2.5 and PM10) in cities – The reduction of emissions from buses and the use of renewable energy contribute to improving air quality in cities.
- Indicator for SDG 12.4: Hazardous waste generated per capita and proportion of hazardous waste treated, by type of treatment – The conversion of waste into energy and the environmentally sound management of waste contribute to reducing hazardous waste generation and increasing treatment.
- Indicator for SDG 13.2: Number of countries that have communicated the strengthening of institutional, systemic, and individual capacity-building to implement adaptation, mitigation, and technology transfer – The adoption of sustainable practices, such as the conversion of waste into energy, contributes to strengthening capacity-building for climate change mitigation.
Table:
SDGs | Targets | Indicators |
---|---|---|
SDG 7: Affordable and Clean Energy | SDG 7.2: Increase substantially the share of renewable energy in the global energy mix | Share of renewable energy in the total final energy consumption |