Petrobras tests flex-fuel turbine generator

By Holly Jessen | January 04, 2010
Posted Jan. 19, 2010

Petrobras Brazil is now generating power using ethanol at its power generation park in Juiz de Fora, located in the state of Minas Gerais.

Brazil's President, Luiz Inácio Lula da Silva, inaugurated an ethanol-run turbine on Tuesday, Jan. 19. The flex-fuel turbine, which was converted from running solely on natural gas, began operating on Dec. 31 and is currently in its optimization and testing phase.

"With this initiative, Brazil reasserts its leading position in ethanol production and use, and Petrobras takes yet another step in the search for alternative sources of power generation," said a Petrobras press release.

The turbine is just one in a power generating park with a 7,028 megawatt capacity. In that park there are 14 thermoelectric plants running on natural gas, 12 on oil and 15 small hydroelectric plants, according to Petrobras.

The thermoelectric plant utilizing ethanol is made up of two 6,000 GE LM aero-derived turbines manufactured by General Electric (GE). Half of the electric plant's 87 megawatt capacity comes from the converted turbine, which can run on both natural gas and ethanol.

"The conversion of the turbine involved the replacement of the combustion chamber, of one of the injector nozzles, and the installation of peripheral equipment (receipt system, tanks, pumps and filters) which allow the receipt, storage and flow of ethanol to the turbine," the press release said.

GE developed the new combustion chamber used for ethanol and natural gas. The two companies have an agreement, for which GE will use the testing data to "improve and market the technology to other plants in the world," according to Petrobras.

Testing will assess four primary areas. The equipment's performance, useful life and emissions will be studied. The data will also be analyzed to discover the economic competitiveness of ethanol compared to other sources of power generation.

So far, atmospheric emission testing has been positive. From Dec. 31 to Jan. 13 the nitrogen oxide (NOx) emissions were reduced 30 percent, compared to the NOx emissions caused by burning natural gas. The Center for Natural Gas and Renewable Energies Technologies established a monitoring station at the power generation park, which will measure, in real time, NOx, carbon oxide (COx) and sulfur oxide (SOx) emissions.

"Power generation from ethanol opens major opportunities for the country, with economic, energetic, and environmental gains," it said in the press release. "In addition to the energetic security derived from diversifying the sources of generation, there is also the creation of a new market segment for ethanol in Brazil and abroad, the reduction of the atmospheric emissions levels, and the possibility of negotiating carbon credits on the international market by means of the Clean Development Mechanism."