JULY 2009

Converting green waste to hydrocarbons

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Click to enlarge - Pictured left to right at the Gulf Coast Energy pilot plant are:  Mark Warner, CEO, Scott Hazen, vice president construction, engineering, Eric Yonker, plant superintendent, Woody Jones, production worker, and Jimmy Edmonds, plant manager.

In April, the City of Hoover, Alabama officially became the first community in the United States to fuel their municipal vehicles with E85 ethanol made from wood waste collected from city public works projects and curbside collection of yard debris.

“To our knowledge and according to the United States Department of Energy, it is the first true application where it is actually fueling vehicles,” said Mark Bentley, executive director of the Alabama Clean Fuels Coalition. This coalition is among 90 “Clean Cities” state-based organizations established under the umbrella of the United States Department of Energy in 1993 to facilitate voluntary public-private partnerships to create viable markets for clean, alternative fueled vehicles.

Hoover, a suburban community just south of Birmingham is the state’s sixth largest city with a population just over 75,000, but leads the state, perhaps even the nation in the per capita use of alternative fuels for municipal vehicles. Of all Hoover’s municipal vehicles, 88 percent are now powered by E85 ethanol, electricity, commercially purchased B20 biodiesel and biodiesel produced from recycled cooking oil donated by citizens and restaurants.  

This first delivery of ethanol to Hoover was only 120 gallons from a Gulf Coast Energy demonstration plant located in Livingston, Alabama – a baby step in what many see as a giant step forward for the United States recycling of municipal green waste via cellulosic gasification into renewable fuels. “We are doing mostly testing with Hoover’s wood waste and will send them another 100 gallons during June and a few hundred more gallons along the way,” said Mark Warner, Gulf Coast Energy’s CEO. For the time being, Hoover is trucking its green waste 100 miles to Gulf Coast’s Livingston demonstration plant. “A far shorter distance than importing foreign oil over 7,000 miles from the Mid East,” said Bentley.

Meanwhile, Gulf Coast is looking for a location and financing to build a full scale production plant in the Birmingham metro area to handle Hoover’s feedstock as well as draw other woody biomass from the Birmingham area. “We have plans for three, possibly four plants in Alabama and we are well on our way in establishing plants in Tennessee and Mississippi. Using technology like ours can help extend the effective life of landfills,” said Warner.

Hoover Mayor Tony Petelos is the city’s biggest advocate of renewable fuels and hopes that Gulf Coast Energy will soon decide on a location for a permanent, large scale plant so the city can begin to work with it. Petelos has stated that his city presently uses approximately 240,000 gallons of E85 annually and generates approximately 1,800 tons of wood waste a year, enough feedstock to produce roughly 350,000 gallons of E85 annually.

Product drums filled with fuel from Gulf Coast’s plant display the colorful signage used by the organization.

Gulf Coast Energy’s technology is based on the Fischer-Tropsch process that dates back to the 1920s and was extensively used by Germany during World War II to convert coal into synthetic fuels. Since then, the process has been improved and Gulf Coast Energy holds licenses to use the latest patents.

Gulf Coast takes in Hoover’s pre-chipped material, essentially wood and leaves. “Hoover does a very good job of separating the woody biomass from grasses, so we don’t see much grass. There’s occasional metal, like cans, but we have magnets to separate that out,” said Warner.

As Gulf Coast Energy expands, it plans to do its own chipping. That’s why it is looking to site its new plants at mothballed chipping and saw mills. There are many of these dormant mills available throughout the southeast due to the loss of paper and pulping operations to foreign competition.

The first step in the Fischer-Tropsch process is to take the chipped material and grind it down to a one-quarter inch size. “In our model woody biomass is most readily available here in the southeast, which is essentially a huge pine forest. It’s very easy to handle and there’s already an infrastructure for handling it. We can also handle landfill waste, pump sludge and switchgrass.” Warner said. “It’s been put out into the general literature that there is not enough corn and soybeans to fuel the country and I agree with that, but there’s more than enough woody biomass and landfill waste to fuel the country. And if we want to get serious about it, we can.”

The use of cellulose to produce ethanol is considered the “second generation” feedstock in the United States – corn being the first. Gulf Coast Energy and other entrepreneurial chemical companies are looking at making cellulosic ethanol from biomass as a threshold product. The catalytic chemical process employed, however, is aimed at a larger objective, reconfiguring molecules into what the Department of Energy classifies at “renewable fuels,” which are biomass-derived hydrocarbons beyond ethanol like kerosene, diesel, gasoline and jet fuel. Gulf Coast, for example, believes that its patented technology takes advantage of the latest advances in carbon re-circulation and waste heat re-use to produce extraordinary yields, high energy efficiency and superior quality biofuel products. Further, the process is a continuous process as opposed to a batch process and is flexible enough to handle multiple types of feedstock to produce a variety of different kinds of biofuels.

In the basic Fischer-Tropsch process (using ethanol as an example of an end product) wood waste goes into a reformation unit where it is converted to gas. An off-stream of mixed alcohols is either directed back to the gasifier to help fuel it, or sent to a raw material dryer. The gas then goes to a Fischer-Tropsch reactor where it distilled and condensed to make the final product, ethanol. Ethanol is then mixed with gasoline with the ethanol component representing from 70 to 83 percent of the mixture to qualify at an E85 fuel. To date there are approximately 1,900 filling stations in the United Sates pumping E85, but more are on the way as E85 production increases and more municipalities switch to E85.

The City of Hoover is running 181 vehicles on E85 and has centralized fueling for its municipal fleet, including a 12,000 gallon E85 tank and pump. Hoover was one of the country’s earliest municipal users of E85 and has been working closely with General Motors (GM) for the past five years on a test program for engine performance burning E85. “We are the largest GM E85 municipal law enforcement fleet. So we sent a sample of the Gulf Coast Energy ethanol for testing to GM before we used it and it met their specifications. The 120 gallons we ran in our vehicles ran perfectly – no problems,” said Dave Lindon, Hoover’s fleet management director.

According to the U.S. Department of Energy, about two-thirds of what we throw into our landfills today contain cellulose and is a potential source of fuel. More importantly, cellulosic ethanol yields roughly 80 percent more energy than is required to grow and convert it. A demonstration project such as the partnership between Hoover and Gulf Coast Energy may prove to the investment community that this technology is economically viable for large scale production of renewable fuel. When oil was at $150 a barrel, interest in renewable energy was at an all time high, but when it fell below $34, investor confidence in renewables fell with it. Now oil prices are climbing again and cellulosic fuels may play an important role in our national energy solution.

In areas that have abundant supplies of fast growing conifers, municipalities are challenged to dispose of huge quantities of waste wood, not only from curbside collection, but from massive downfalls caused by periodic storms and from commercial companies clearing land for development. Green waste can be viewed either as a problem for landfills, or as an unexploited natural resource that can be converted into renewable fuels. “We don’t produce corn, but we can grow pine trees,” said Mark Bentley of the Alabama Clean Fuels Collation. “If we can establish a few large scale plants in Alabama to convert tree waste into cellulosic fuels it can be used to power entire fleets.”