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Power Struggle: In Search Of Energy Alternatives For Puerto Ricos Industrial Sectors
Gasification and fuel cells seen as options for cost-efficient, cleaner energy sources
By MARIALBA MARTINEZ
March 18, 2004
Alternatives to traditional energy sources such as petroleum and natural gas will be tested this year to see if they prove more cost-efficient and environmentally sound for Puerto Ricos manufacturing industry.
Industry sectors islandwide are hoping to find reliable energy sources that will prevent costly interruptions to their operations from power outages. The latest example happened March 10, when a power outage at Banco Populars operations center in Cupey caused automated teller machine (ATM) and debit card networks to be unavailable to customers for three hours. The breakdown affected the banks more than 500 ATMs plus thousands of terminals in stores and elsewhere.
That same day, the Puerto Rico Electric Power Authority (Prepa) announced it was negotiating the price it would pay for electricity from Caribe Waste Technologys gasification plant, for integration into its islandwide power grid. Gasification is a process whereby waste is turned into gas.
Finding alternative sources of energy has been on the islands agenda since the 1990s, when the Rossello administration allowed the establishment of private natural gas and coal plants, which could sell their electricity to the agency. Industry experts who recently visited the island spoke about new technologies for energy production.
One process uses hydrogen and oxygen to convert waste into a cleaner gas. Another uses fuel cells, which contain two electrodes (a cathode and an anode) on either side of an electrolyte to generate a reaction whereby hydrogen and oxygen combine to form water, producing heat and electricity in the process. Both methods can be used to power combined-electricity turbines that run on gas or steam.
Clean, renewable energy from waste
In a similar project to Caribe Waste Technologys gasification plant in Caguas, the Puerto Rico Industrial Development Co. (Pridco) will invest $1.7 million to construct a Plasma & Renewable Energy Technology Center at the University of Turabo in that municipality.
The plant will initially process cruise ships waste into renewable energy. The next step will be for the plant to process hazardous waste for the pharmaceutical manufacturing industry.
"This project is part of Pridcos strategic plan for economic development," said Pridco Science & Technology Office Director Manuel Hormaza. "We are moving toward promoting Puerto Rico as a technology research & development center that offers innovative alternatives for modern industrys needs."
Solena Group, a U.S. corporation with five U.S. and foreign subsidiaries that develop and market power technology solutions and trade energy in all its forms, will build a Plasma Gasification Vitrification (PGV) reactor at the University of Turabo. The reactor will convert low-value fuels and feedstocks into a low-heating-value synthesis gas, or SynGas. SynGas contains carbon monoxide and hydrogen, which are used as the primary fuel in Solenas gas turbines to produce electricity.
"Solenas gasification technology is a more reliable, efficient, and distributed source of renewable energy for the electric utilities industry than wind or solar energy," said Solena President & CEO Robert Do. "Landfills are reaching their capacity, and there is a scarcity of new sites. With SynGas, dependency on fossil fuels is avoided and the power plants can easily be connected into existing power grids (systems of high-voltage transmission lines that carry power from generators to local distribution networks).
"The process emissions are also significantly lower than other technologies. By being classified a fuel manufacturing plant by the U.S. Environmental Protection Agency, hazardous waste can be turned into marketable fuels and chemicals," said Do.
Solenas Integrated Plasma Gasification Combined Cycle (IPGCC) technology uses PGV technology to convert waste materials such as coal waste, petroleum coke, and biomass through oxidation, a process that uses temperatures of 7,232 degrees Fahrenheit to 9,032 degrees Fahrenheit to release SynGas, a mixture of hydrogen and carbon oxide. Solenas special gas turbines can be deployed in a combined cycle with steam turbines, producing 10 megawatts (MW) to 300 MW. The turbines can be adapted to produce energy from distillate, naphtha, methane, or natural gas.
An added benefit of IPGCC is that it reduces greenhouse gases and acid rain. SynGas is about 5% more efficient than coal-fired power plants and 15% to 20% more efficient than incinerators. This translates into carbon oxide emissions of 5% to 20% per kilowatt (kW). Nitrogen oxide emissions are less than 10 parts per million, which is lower than coal or traditional waste-to-energy plants.
In addition, byproducts of the PGV process can be recovered for additional income. Instead of ash, PGV produces molten slag that is used as construction material in concrete or roadbed aggregate, construction fill, brick making, architectural tile, and shingles. Sulfur can also be recovered as sulfuric acid or elemental sulfur for industrial or agricultural applications, respectively.
Fuel cells kept Central Park lit during 2003 blackout
During the August 2003 blackout that hit the U.S. east coast and Canada, there were a few areas that remained lit thanks to fuel cells connected as backups to the electricity grids. These included the police station in Central Park and West Points Saratoga Navy Station.
Fuel cells had been a well-kept secret at military installations, where they have been tested since the 1980s by the U.S. Army Corps of Engineers Engineer Research & Development Center. Michael Binder, manager of the U.S. Department of Defense Fuel Cell Program, selected dozens of sites throughout the U.S. to test the effectiveness of the fuel cells under various environmental conditions such as extreme heat and cold, or for different uses.
"In the original program, all bases could use 200 kW easily as they were grid-connected," said Binder. "The primary difference was how we used the heat that the fuel cells made. If you can recover the heat, in some cases you can get up to 90% fuel use or efficiency. So we used the heat for boilers, to warm swimming pools, for domestic hot water, in hotel-type barracks, laundry facilities, and hospitals."
According to Binder, fuel cells are extremely clean and have essentially zero emissions. The cells are so dependably clean that in the Los Angeles basin, one of the most restrictive environmental zones on the U.S. mainland, facilities using fuel cells are exempted from the requirement for air-emission permits.
Fuel cells are a power source that produces heat and water plus cooling temperatures if used as absorption chillers, but they havent become widely popular yet because of their capital costs.
"Operating costs are cheaper but capital costs are very high," said Binder. "To be competitive in the power market, the goal is $1,500 per kW installed. The cheapest fuel cell right now is $4,000 per kW plus installation, which could run from $4,200 a kW to $5,000 a kW for the entire system. At the residential scale, costs run from $10,000 a kW to $25,000 a kW installed. Fuel cells today are meant for environments of low natural gas and extremely high electricity prices, then the operational costs might provide sufficient savings to make them viable."
Some sectors of the manufacturing industry, such as chemical companies, might find investing in fuel cells a good way to reduce their emissions. Binder said chemical plants that produce hydrogen as a byproduct (which has to be flared, or burned, in a boiler) are ideal sites for fuel cells. These plants also generally use DC power as an input. Fuel cells can reduce their costs since the hydrogen is turned into AC, thus eliminating the DC-to-AC conversion.
EcoElectrica General Manager Ernesto Cordova, who supervises one of two privately owned electricity producers on the island, said Puerto Rico must consider a new model of electricity distribution that is reliable and cost-efficient.
"There are two big challenges for Puerto Ricos power system," said Cordova. "One is that the islands future requires rethinking the model and making an investment to achieve reliability. The second is meeting the demand of infrastructure projects already designed and implemented, such as the Urban Train. We need clean, reliable power for the private sector, and the government should be interested because it brings economic development and business opportunities to export technology outside the island. The universities should also be involved since this is where the knowledge is and where good ideas will become the commercial projects of the future."
This Caribbean Business article appears courtesy of Casiano Communications.