Waste-to-Energy Chemistry Senior Seminar Diane Colette Starrantino Methodist University Department of Chemistry 09 December 2009

Green Chemistry Rethinking Waste In recent years, “Green Chemistry” has become an area of significant research interest. From this research area, specific goals have emerged, such as minimizing waste (municipal, industrial, or commercial), increasing recycling, and energy sustainability.

4 Topic Outline Introduction: Rethink ‘waste’ Waste-to-Energy Video What happens to our waste? –Biomass –Landfill/Incineration –Municipal Solid Waste (MSW) Graphs Chemistry of WtE: Overview –Combustion –Energy output –Current Technology –The Global Impact: Who cares? Why care? How? –Pollution Abatement Technology Future Trends Scientist Role –12 Principles of Green Chemistry –Life Cycle Assessment (LCA) Opposing Viewpoints Conclusion References Questions

What happens to our waste? Figure 2: Department of Energy Figure 1: Energy Information Administration

Municipal Solid Waste In 2008, Americans generated about 250 million tons of trash and recycled and composted 83 million tons of this material. Figures 3 & 4: MSW in the US: 2008 Facts & Figures Environmental Protection Agency

Chemistry of Waste-to-Energy Combustion Reaction: Carbon Material + O 2 ======> CO 2 + H 2 O Generates steam that can drive a turbine in an electric power unit by converting MSW into a viable renewable energy source A typical WtE plant generates about kWh per ton of biomass waste (mix of MSW that can include paper, plastic, organics)

Waste-to-Energy Output WtE plants nationwide dispose of more than 90,000 tons of trash each day while generating enough clean energy to supply electricity to approximately two million homes nationwide

Current WtE Technology Direct Firing Co-Firing Biomass Gasifiers

The Global Impact: Implications & Abatement Rules & Regulations Pollution Prevention Act 1990 Clean Air Act 1990 Energy Policy Act of 1992 Stack Emissions chlorinated dibenzo-p-dioxins, chlorinated dibenzofurans, and certain polychlorinated biphenyls CO2, N2O heavy metals such as: Cd, Pd, Hg, Pm, and HCl, as well as, ash containing trace minerals

Pollution Abatement Technology Powdered Activated Carbon Baghouse Filtering (Most Common) Selective Catalytic Reduction (SCR) Wet-Spray Humidifiers Dry Lime Injection Cyclone Separators Electrostatic precipitators Afterburners Venturi Scrubbers

Figure 5: WtE Plant Diagram Peswiki.com

Future Trends Reducing MSW Dioxin Emissions for maximum power output One-step drying, pyrolysis, gasification, incineration, and ash vitrification Gasification Gas/Plasma Fluidized Bed Combustion Co-Combustion System Alternative biomass Sewage sludge Cellulosic Feedstock

12 Principles of “Green” Develop, design, & integrate Educate to encourage progressive action in the critical areas of green chemistry, renewable energy, and climate change. The principles are a set of methodologies to accomplish the goals of green design and sustainability.

Life Cycle Assessment Figure 6: WtE Life Cycle Model Peswiki.com

Opposing Viewpoints Proponents –MSW to Ethanol reduces net energy use compared to gasoline –Reducing dependence on foreign oil –Energy security –reduced GHG by 65% compared to gas or 5% to corn-ethanol –Price of corn down –Converting waste-to-energy by accessed methods reduces landfills Opponents –Environmentalists –Initial Project Costs high –Eliminate the ‘status quo’ attitude of the past –Shift in policies, ethics, from traditional MSW –Protecting the bottom- line of capitalism $$$ –Eye-soar/property devaluation

Being Green Data and facts show that waste-to-energy avoids greenhouse gas emissions, generates clean renewable energy, promotes energy independence, and provides safe reliable disposal services. The choice is clear

Lasting Thoughts “Waste-to-energy is turning a problem into an energy solution.” — Rick Brandes, Chief, Waste Minimization Branch, Office of Solid Waste and Emergency Response, US Environmental Protection Agency as reported in The Examiner, 7/16/07

Spring 2010 ACS National Meeting Spring 2010 ACS National Meeting San Francisco, California March 21-25, 2010 Abstract submissions open August 24, 2009 With the conference theme of “Chemistry for a Sustainable World,” green chemistry and engineering topics are expected to be plentiful at the conference. Submit your abstracts now.Submit your abstracts

References Exploring Ways to Use Biomass Energy Exploring Ways to Use Biomass Energy U.S. Department of Energy Consumer Guide Biomass Program Biomass Program U.S. Department of Energy Alternative Fuels Data Center Alternative Fuels Data Center U.S. Department of Energy U.S. Department of Energy Bioenergy Feedstock Information Network Glossary of Biomass Terms Glossary of Biomass Terms National Renewable Energy Laboratory Pure Energy Systems Database of WtE Federal Drug Administration National Energy Renewable Laboratory Environmental Protection Agency Energy Information Administration Department of Energy ACS Web Editions

Questions?