Upstream Diversity

Sewer sludge, food and beverage wastes and plastics can provide abundant feedstock for biorefineries located onsite
By Bryan Sims | April 25, 2011

The philosophy behind biomass refining is simple: build a renewable, sustainable economy using domestically sourced biomaterial (ideally wastes) while leaving the smallest carbon footprint possible. But there are high-energy, nonbiomass wastes such as unrecycled or unrecyclable plastics, for instance, that are dumped in landfills to sit for thousands of years. It is at this tangential juncture where biomass refining and the waste-to-energy industry cross.
There is a growing number of companies within the biorefining landscape, like Tigard, Ore.-based Agilyx Inc., that are utilizing “unconventional” waste feedstock streams, such as waste plastic in municipal solid waste (MSW), for the production of crude oil that can be further refined into fuels and other chemical intermediates. 

Founded in 2004 under its former name Plas2Fuel, Agilyx employs what CEO Chris Ulum calls a “distributed-manufacturing approach,” whereby the company aims to deploy its modular conversion units at active municipal and industrial waste aggregation sites, such as material recycling facilities (MRFs), transfer stations and plastic recyclers. This, according to Ulum, eliminates costly shipping expenses associated with larger waste processing plants.

“When you look at the municipal waste stream, between 12 and 13 percent of that consists of waste plastic,” Ulum tells Biorefining Magazine. “The whole idea was that we need to put the technology where the waste already resides rather than unnecessarily transporting the waste to the technology.”

Agylix’s waste plastic conversion technology is designed to handle the inherent heterogeneity and contamination found in mixed, waste plastic feedstocks. Ulum says there are no limitations to the plastic resin types the technology can process. Additionally, the plastic can be co-mingled and there’s no need to clean the plastic of any contaminants prior to processing. Once the plastics enter the conversion vessels, the material is indirectly heated until converted into a liquid and eventually into a gas. With a series of controlled pressure and temperature adjustments, the gases are pulled through pipes into a central, condensing chamber. There, the gases cool off and contaminants are siphoned away. The synthetic crude oil that remains is transferred into tanks where they can be transported to oil refineries for further conversion into heating oil, diesel or gasoline. Additionally, Agilyx’s technology has evolved to the point of attracting some of the largest waste aggregators, such as Waste Management Inc., in its latest $22 million Series B round in late March. With Waste Management, the investment was led by Kleiner Perkins Caufield & Byers, another newcomer in the investment, and Total Energy Ventures International, an affiliate of oil and gas major Total S.A. Existing investors, Chrysalix Energy Venture Capital, Saffron Hill Ventures, and Reference Capital also participated in the round.

Agilyx first deployed its commercial system in 2008 at a beta customer site where the company shipped its first 25,000 gallons of crude oil. It has since optimized its technology, demonstrating the viability of the plastic conversion technology at its showcase commercial facility in Portland. To date, the company has sold more than 120,000 gallons of crude oil from 1 million pounds of plastic that would otherwise have been landfilled or incinerated. According to Ulum, Agilyx is the lone waste plastic-to-oil producer in the world to have locked up long-term off-take arrangements with an oil refiner in the Pacific Northwest.

The technology is capable of recycling 20 tons of plastic per day and producing 4,500 gallons of crude oil a day from a typical eight-vessel system. On average, approximately nine pounds of mixed plastic can be converted into one gallon of ultra “sweet” synthetic crude oil, with a process energy ratio of about 7.3-to-1, meaning for every Btu input, 7.3 Btu of output are created in the form of hydrocarbon energy. 

According to Ulum, Agilyx’s novel conversion units are ideal for counties, municipalities or small townships that are looking for productive means of separating plastic waste streams from MSW or industrial waste debris into saleable crude oil.

“One of the things that we think is a real virtue of our solution and our technology is that it’s scalable—we don’t sell a small, medium or large system,” Ulum says, “we sell a basic building block that then can be scaled to match the feedstock processing requirements for our clients. What that means is that we can have a solution that is good for not only large cities, but also small towns.”

Agilyx estimates that waste plastic currently takes up to approximately 24 percent of the space in U.S. landfills. While the company may not become the panacea for eliminating all the waste plastic that currently stresses landfills, Ulum knows that his company and others have to start somewhere.

“Plastics are still the most difficult waste stream to recycle when compared to paper, metal and glass,” he says, adding that U.S. recycling rates stand at about 10 percent at present. “Our technology addresses the other 90 percent and it provides a solution for the end-of-life of those plastics that’s superior to landfilling, incineration or exportation.”

Like Agilyx, Akron, Ohio-based Polyflow looks to attack a similar strategy by capitalizing on the abundant waste plastic streams for production of finished gasoline and diesel. Using conversion technology invented in the 1970s and advanced in 2002 by the Ohio Polymer Enterprise Development, a University of Akron initiative aimed at commercializing technologies developed by startup companies, Polyflow’s technology can handle difficult-to-recycle waste polymer, such as tires or powdered paint waste, without the use of catalysts or gasification, and it operates at low temperatures and pressures, according to Joseph Hensel, director of technology and board member of Polyflow.

“If you look at feedstocks available today, the one that has the highest availability is coal,” Hensel says. “The second is natural gas. The third is woody biomass. The fourth is polymer waste. Of those four, polymer waste has the highest Btu content. It’s a good feedstock, it’s readily available and it’s being largely ignored as a resource.”

In April, Polyflow received $1.6 million from The Ohio Third Frontier to advance the company’s scale-up effort to build and operate a facility between Cleveland and Akron that’s capable of handling 16,000 tons of waste polymers annually. Polyflow is collaborating with Youngstown State University, the City of Stow, Defense and Energy Systems, PolyOne and Chemstress Engineering, and was one of eight companies to receive funding. According to Hensel, the facility should be operational within a year. The company plans to open a larger plant capable of processing 150,000 tons of waste polymer annually within three years.

“The 16,000-ton facility would only take 3 percent of the polymer feedstock in the Cleveland/Akron area,” Hensel explains. “The full 150,000 ton facility would take about 27 percent of the polymer waste in the area.”

While waste plastics may be an attractive type of feedstock for some, others see opportunities in capitalizing on different forms of waste feedstocks to produce fuels and chemicals, such as food and beverage wastes, or using wastewater to grow algae.

Branching Out

Statesville, N.C.-based Custom Environmental Technologies Inc.’s core business may be wastewater treatment, but that doesn’t mean it isn’t interested in exploiting waste material that feed on sewer water or effluent discharged from food and beverage manufacturing plants by turning it into biofuels. Founder Ron Grayson says the company wanted to broaden its wastewater treatment solutions for its customers by capturing the most out of the wastes it treats by creating additional revenue, such as ethanol from food and beverage effluent or biodiesel from algal oil.

“The world has changed when it comes to our company, because our company has always been geared to treating wastewater from manufacturing, such as the textile, pulp and paper or food and beverage plants,” Grayson says. “For us, going that route was a natural step.”

The company has agreements in place with a few partners, both domestically and internationally, for projects that involve capturing sewage sludge for conversion into biodiesel or ethanol, and cultivating algae on wastewater where it can be harvested and extracted for biodiesel production, Grayson says.

“We can use our technology at dairy farms, distilleries or sugar mills,” Grayson says. “There’s all kinds of industries we can go with. It’s not just a sugar-based waste stream.”

One of those projects in particular was originally announced in 2009 that involved the building of a 5 MMgy ethanol plant in Statesville using food processing waste. The project, a joint venture between CET and Maumee, Ohio-based Green Castle Energy Inc., is “still going forward,” Grayson says. Phase 1 of the project would use wastewater and sludge in fermentable starches and sugars in a standard ethanol process. Phase 2 would incorporate waste paper streams. CET would contribute its technology to precipitate biosolids out of food processing wastewater for the project. While he couldn’t disclose further details regarding a timeframe on a groundbreaking, Grayson isn’t banking on this single project to fulfill his company’s biorefining strategy spun out of wastewater treatment routes.

“We’ll never have a shortage of waste feedstock streams in the industries we serve,” Grayson says. “You can count on that.”
Author: Bryan Sims
Associate Editor, Biorefining Magazine
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