Weighing the options of organics waste management

Food waste continued to be a pressing issue at Waste Expo Together Online, with the session “Anaerobic Digestion, Composting, Successful Case Studies, and Comparison of Organic Waste Management” bringing together panelists across North America to discuss new advancements in organics technology.

Featuring Patrick Sullivan, senior vice president for SCS Engineers; Brian Paganini, vice president of Quantum Biopower; Eric Hebert, president of Bulk Handling Systems (BHS); Yaniv Scherson, managing director of Western U.S. operations for Anaergia; and Stuart Buckner of Buckner Environmental Associates LLC as moderator, the session walked viewers through the changing landscape of organics waste management.

Scherson kicked off the session with a presentation on how Anaergia, a Canada-based waste recovery company, is helping the state of California reach it’s carbon neutrality goal by 2045 through the production of renewable natural gas (RNG).

With recent work from NASA Jet Propulsion Laboratory (JPL) identifying methane released from landfills to be the No. 1 source of methane release in California, Scherson said the only way to achieve carbon neutrality in the state is through building RNG facilities.

“Diverting organic waste from landfills to release this greenhouse gas and generation renewable natural gas for carbon negative energy is central,” he said. “…Our model in the state of California is to intercept the organics at existing transfer stations with machinery, [like] the OREX Organics Extrusion Press that we manufacture, and take it to wastewater [treatment] plants.”

An example of this process can be seen through a partnership between Anaergia, the South Bay Side Waste Management Authority (SBWA), Silicon Valley Clean Water (SVCW), and four other wastewater plant agencies.

Some breakthrough work that’s being conducted by SVCW is showing that the co-digestion of sludge with food waste, or organics fractions, from municipal solid waste (MSW) is stable, enhances digestion, increases gas production, increases solids destruction and helps with dewatering.

“Bottom line, [this process] actually enhances the digestion process at wastewater plants by co-digesting with organic fractions from solid waste,” Scherson said.

Paganini presented next, representing Quantum Biopower, a Southington, Connecticut-based food waste solutions integrator.

Operating the only commercial food waste anaerobic digester in New England, Quantum Biopower’s facility can process up to 40,000 tons of food waste per year and has an annual energy output of 10,700 MWh.

“Our process takes in source separated organic material only, we do not take a mixed waste fraction into this facility,” said Paganini. “So, every part of our being here comes from educating our customers and our producers about the principles of good food waste diversion… Our mission, frankly, is to help customers on both the private and public side achieve their diversion goals.”

According to Paganini, all of the biogas produced at the company’s facility run through a combined heat and power unit. The resulting energy created is then taken advantage of by surrounding communities and helps to power municipal infrastructure.

“We’re seeing a rising demand for decarbonized fuel, such as RNG,” said Paganini. “But not only is it becoming an increasing demand, it’s now becoming a necessity.”

With companies like Con Edison imposing gas moratoriums in areas of Connecticut, Paganini said more local utilities are seeking more indigenous supplies of decarbonized fuel.

Herbert, who is also the CEO of Zero Waste Energy, focused on a collaboration between BHS subsidiaries to create a large Municipal Solid Waste (MSW) Diversion project located in the California Bay area.

The project, which will come in two phases, will create a system to process mixed commercial and residential MSW, as well as some additional SSO in a designated compost facility, to achieve 75 percent diversion as mandated by California’s carbon neutrality law.

The first part of the system, called the Organic Material Recycling Facility (OMRF), is an in integrated waste management facility that aims to offer centralized, high-volume processing. Designed to process 100 tons per hour, Herbert said 50 percent of the material will be organic materials.

The fraction of the waste stream that is organic will be passed to the second part of the system, called the Organics Material Composting Facility (OMCF).

“What we found is out of that MSW stream about 60 percent of it was suitable for further processing into compost,” said Herbert.

The organic material at the OMCF is pre-processed and then sized in rotary drum reactors that can break organic material down to less than 1-inch in size. “That material is easily screened and separated between the inorganic [and] organic fractions, that makes for an easy compost feedstock,” Herbert said.

“We also added what we call our Smarturn system, [which] is something developed by Zero Waste,” he added. “[With the system], material is added to one end of the lanes and as the lane turner rolls through that lane over the course of a 21-day or three week process, the material then exits the lanes and is a fully developed and stabilized compost for processing.”

Sullivan, who analyzed each presenters processes’ for organic waste management, concluded there is no “silver bullet” when it comes to options for organics from an emissions standpoint.

“There’s no one scenario that says, ‘This is the best,’ because each one has some trade-offs and pros and cons in terms of impacts and benefits,” he said. “The good thing is every one of these scenarios can be improved from an emissions profile with levels of control.”