Florida Innovates with Its Eucalyptus and Citrus for Biomass Production

19 january 2013

By taking full advantage of both its natural subtropical climate and its own citrus resources, Florida’s fledgling biomass energy sector looks to be finally coming into its own.

Two recent initiatives tackle biomass conversion from very different angles, however.  The one that is arguably further along in its financing will convert biomass from Eucalyptus trees into electricity for input onto Florida’s power grid, while a second project aims to produce commercial ethanol from citrus waste.

U.S. EcoGen (Ecogen), a Florida- and Maryland-based bioenergy company, has signed an agreement with Florida Power and Light (FPL) to provide 180 MW of electricity created from the conversion of Eucalyptus biomass via synchronous steam turbine generators.

FPL says such woody biomass should provide enough power for as many as 50,000 of its residential customers beginning in 2019.

Pending approval by the Florida Public Service Commission, U.S. EcoGen (Ecogen) plans on building three power plants at a cost of $900 billion, which will be located in the Florida counties of Mitchell, Okeechobee and Clay.  A fourth $300 million Ecogen plant, which the commission has already approved, is set for Polk County, Florida and will deliver as much as 64 MW to Progress Energy Florida, Inc.

FPL projects its own agreement with the three Ecogen plants should, over three decades, save its customers as much as $167 million.

“This will be the first time FPL has purchased biomass feedstock specifically grown for electricity power production,” said FPL spokesperson Sarah Gatewood.  “The majority of our energy comes from natural gas and nuclear power.”

As Ecogen’s CEO William Quinn explains, Eucalyptus grandis is a woody biomass tree species that grows easily in subtropical climates like south central Florida.

“The metrics we consider — BTUs per acre per year or tons per acre per year — just make the decision of planting eucalyptus in this climate compelling,” said Quinn.

And unlike some species, even after harvest, a Eucalyptus tree can regenerate from its own stumps.

Ecogen’s plan is to acquire as much as 10,000 acres per power plant in which to grow sustainable Eucalyptus while at the same time financing the four plants’ construction.

While waiting for the company’s new Eucalyptus plantations to fully mature, Ecogen will use what it terms “bridge fuel” feedstock; that is, biomass from existing tree resources for conversion into electrical power.  The first Eucalyptus will be ready for harvest two years after planting.  But for sustainability, harvests will subsequently be rotated on a four year basis.

When Ecogen does fully switch to Eucalyptus, Quinn says, it will be chipped and combusted in what Ecogen terms a closed-loop system.  That means the company will use biomass grown and harvested in close proximity to the plant as fuel to generate some 565,000 pounds of steam per hour.

“All four of our plants,” said Quinn, “will combust the biomass in a boiler to create high-pressure, super-heated steam that then will move through a 60-MW steam turbine to generate the electricity.”

Quinn says that most nuclear and coal power plants are equipped with 300- to 400-MW steam turbine generators, so from Florida Power’s perspective, this could seem like a boutique project.

Even though 180 MW represents less than one percent of Florida Power’s total generating capacity of 24,000 MW, Gatewood says that the agreement still represents an important renewable initiative for FPL, Florida’s largest utility with some 4.6 million customers.

“The most difficult thing is attracting capital during the development period; a period which requires a lot of engineering and environmental work,” said Quinn.  “This has also been a very difficult environment to raise capital because financial institutions haven’t had liquidity.”

As Quinn readily admits, the road to raising capital to fund the Eucalyptus project has been a hard slog.  But he says it’s still inherently less risky than basing a biomass energy project on more volatile liquid commodities like ethanol.

However, a 2007 plan to turn a portion of Florida’s citrus waste — mostly peels and membranes from grapefruit and oranges — into commercial-quality ethanol caught the attention of FPL Energy, LLC, one of Florida Power’s subsidiaries.

It was to have been the first-ever commercial scale citrus waste to ethanol plant.  And it was to have been headed by David Stewart, a Boca Raton-based entrepreneur whose Citrus-Energy, LLC had an agreement with FPL Energy to produce ethanol from an estimated 5 million tons of the state’s annual production of citrus waste.  Heretofore, such waste has traditionally been used as low-value cattle feed.

Estimates are that a fully-mature citrus waste to ethanol industry in Florida alone could produce over 60 million gallons of ethanol per year, or about one percent of the state’s annual gasoline consumption.

Although Stewart’s project never saw fruition, which he says was due to both lower oil prices — that made the prospect of citrus-based ethanol less attractive at the pump; and, the 2008 financial crisis — which Stewart says caused FPL’s enthusiasm for the project to wane.  However, the entrepreneur maintains that once oil hits more than $120 a barrel, such citrus-based ethanol could become viable.

Yet retired USDA research chemist Karel Grohmann questions whether Stewart’s research was even far enough along to actually create ethanol in the first place.

The Florida-based Grohmann has been working on the conversion of citrus peel waste to ethanol for the last two decades.  He says the biggest financial sticking point for the process has been the untenably high cost of the enzymes needed to actually convert the peels’ carbohydrates into sugars.  It is these sugars which are then fermented into ethanol, technically a form of alcohol.

But Renewable Spirits, LLC, of Delray Beach, with Grohmann as Principal Investigator, has found a way to drastically cut the amount of enzymes needed for the citrus waste to ethanol conversion.

As a result, Renewable Spirits now has an economically-viable pilot plant currently processing and funneling some two tons of citrus waste into 10,000 gallon ethanol fermenters.

Grohmann says that his own company’s ethanol can be made cheaper from citrus waste than corn, and notes: “So, right now, we’re looking for commercial partners.”

Even so, as Quinn notes, with the massive uncertainty of such liquid commodities markets, there’s no guarantee on pricing in what he terms a “marketplace dominated by large international oil and gas companies.”

In contrast, Quinn says Ecogen’s current plans to use Eucalyptus biomass for the creation of bio-energy is a more financeable and risk-averse way of proceeding.  “With all these biomass products, there are commodity and price risks,” said Quinn.  “By growing the biomass on our own, we at least solve the commodity risk.”

Quinn says that thus far, his own company has also been smart about negotiating long-term contracts.

But no matter which project sees commercial fruition first, Ecogen and Renewable Spirits should both enhance the “long-term” future of the Sunshine state’s biomass to energy sector.