(498a) Title: Sustainable Waste Management Moving Toward Circular Economy

Author: Prof. Tapas K. Das, PhD, PE, DEE, FAIChE, FIIChE, FICS

Department of Civil Engineering, Saint Martin’s University, Lacey, WA 98503, USA

E-mail: TDas@stmartin.edu

Prepared for Presentation at the AIChE Annual Meeting, Nov. 2-6, 2025, Boston, MA

ABSTRACT

Sustainable waste management developed in conjunction with resource conservation, increased efficiency as supported by zero discharge and zero emission are fundamental in building environmental full stability. Our future depends upon truly and deeply developing a symbolic relationship between environment and resources. A future where products are designed through the “12 green engineering principles” for multiple cycles of use, and manufacturing cycles are carefully aligned, so that the output of one process always feeds the input of another. What is currently regarded as simply emissions and discharges, manufacturing by-products as "waste", in “circular economy” they become raw material, nutrients in “supply chain” for new product cycles. Waste resource utilization is a powerful alternative to current "linear economy" (make, use and dispose).

A case study is presented on a state-of-the-art municipal solid waste-to-energy (WtE) plant located in Spokane in the State of Washington can process 800 tons daily. WtE or energy-from-waste (EfW) is the process of generating energy in the form of electricity. The WtE plant is designed to reduce the emissions of air pollutants using various pollution control technologies.

The WtE facility is utilizing wastes as an input to generate valuable outputs, including but not limited to growth of local economy, job creation, as well as protecting the local environment. Typically half of the energy content in MSW is from biogenic material, considerably less carbon and methane into the air than having waste decay away in landfills. Consequently, this energy is recognized as renewable energy according to the waste input, and as a result the energy yields and profit generated can be accounted for circular economy. And the WtE could play an important role in the transition to a circular economy, the waste hierarchy must be used as a guiding principle to ensure that waste minimization, prevention, reuse, and recycling are not averted.

Key References:

Anastas, P.T. and Zimmerman, J.B. (2003). Design through the 12 Principles of Green Engineering, Engineering Science and Technology, 37(5), 94A-101A.

Averyt, C. (2018). Personal Communication, The City of Spokane Waste-to-Energy Facility, Operation Superintendent, Spokane, Washington, USA.

Das, T. K. (2005). Toward Zero Discharge: Innovative Methodology and Technologies for Process Pollution Prevention, John Wiley & Sons, 2005.

Toward Zero Discharge: Innovative Methodology and Technologies for Process Pollution Prevention | Wiley

Das, T. K. (2020), Industrial Environmental Management: Engineering, and Science and Policy, 1e, John Wiley & Sons, 2020.

Industrial Environmental Management: Engineering, Science, and Policy | Wiley

Weetman, C. (2017). A Circular Economy Handbook for Business and Supply Chains: Repair, Remake, Redesign, Rethink, Publisher: Kogan Page, London, New York, New Delhi.

Remediation of Plastic and Microplastic Waste, Editors: Mondal, Surajit, Das, P., Mondal, A., Paul, S., Pandey, J. K., and Das, T. K., CRC Press, 2024.

Remediation of Plastic and Microplastic Waste | CRC Press, Editors: Mondal, Surajit, Das, P., Mondal, A., Paul, S., Pandey, J. K., and Das, T. K.

Keywords: Waste-to-Energy, Sustainable Waste Management; Circular Economy