Following the initial success of the world’s first use of sugarcane-based ethanol in a gas turbine system, GE (NYSE:GE) has received a contract from Brazil’s federal energy company, Petrobras, to convert a second unit at the site to burn this alternative fuel. The power plant serves the city of Juiz de Fora, located northwest of Rio de Janiero.
"Petrobras and GE formed a successful partnership for the conversion of a first aeroderivative gas turbine at UTE Juiz de Fora (MG) for dual-fuel operation—natural gas or ethanol. It is the first power plant in the world to operate with ethanol to generate electricity. Now, the partnership is repeated for the conversion of the 2nd turbine at UTE Juiz de Fora. This is another Petrobras initiative to diversify sources for power generation, allowing greater flexibility in its power plants," said Maria da Graça Foster, Petrobras director of gas and energy.
Currently, the Juiz de Fora Power Plant is a simple-cycle, natural gas plant with a total capacity of 87 megawatts. The plant has two GE LM6000 PC gas turbines, one with GE-modified combustors that enable the use of ethanol as well as natural gas. This dual-fuel capability enhances the plant’s energy security and reliability by providing a valuable alternative fuel source for the power plant that previously had only one available fuel.
“GE’s strategic marketing group has recently concluded that electricity demand is expected to double in the next 20 years, while demand for clean water may triple. With this growth, a greater demand for unconventional fuels, especially those that help control atmospheric emissions, is likely,” said Darryl Wilson, vice president—aeroderivative gas turbines for GE Power & Water. “To better support this rising need for reduced environmental impact and improved plant economics, we are focused on developing alternative fuel solutions, like the project at Juiz de Fora, which will further augment the portfolio’s existing performance flexibility.”
The second of the two GE LM6000 PC aeroderivative gas turbines installed at the plant will now be retrofitted to burn ethanol to produce electricity on a full commercial scale. This contract signals another significant milestone in using sugarcane-based ethanol to fuel power-generating gas turbines, following the passage of the 1,000 hour test and commercial acceptance of Juiz de Fora Unit 1 in May.
As the world’s second largest producer of ethanol and the world’s largest exporter, Brazil will benefit from incorporating this highly efficient biofuel, which can provide a reduced-emission power generation alternative to diesel oil or other fossil fuels where natural gas supplies are low.
The environmental benefits of using sugarcane-based ethanol1 are substantial:
• Reduces carbon dioxide (CO2) emissions by approximately six percent, or 6,500 metric tons. This is equivalent to the annual CO2 emissions of more than 1,800 cars on Brazilian roads.
• Reduces water consumption (used as a diluent in the combustion process) by approximately 20 million liters. This is equivalent to the amount of water used by 72,000 people in Sao Paulo on an average day.
• Eliminates 100 percent of sulfur dioxide emissions (approximately 73 metric tons).
• Reduces nitrous oxide emissions by approximately three percent, or 3.3 metric tons.
GE and Petrobras have completed five months of demonstration runs that validated the use of ethanol as an alternative fuel, as well as ensuring that emissions are within the expected limits. GE is providing the conversion technology, engineering and field support during conversion and commissioning.
During the last five months, the first ethanol-fired plant at Juiz de Fora has been shown to allow operation of hydrous and anhydrous ethanol, provide approximately the same power and efficiency as natural gas, allow for reduced water use for NOx control and result in low Aldehyde emission levels, within the allowable parts per billion range. The Petrobras project has demonstrated about a 30 percent NOx reduction using the same amount of water.
Flexibility is a key characteristic of GE’s aeroderivative product portfolio. From supporting a wide variety of operating profiles to fast, easy, modular maintenance programs, GE’s aeroderivative gas turbines support the operating needs of its global customers.
Sugarcane-based ethanol in gas turbines means sweet success for Brazil, GE