Big Biomass

European energy provider Dalkia recently commissioned the largest biomass combined-heat-and-power plant in France. Its co-location with a paper mill provides a number of beneficial exchanges between the two operations.
By Lisa Gibson | April 29, 2011

In September, European energy giant Dalkia commissioned the largest woody biomass-fueled, combined-heat-and-power (CHP) plant in all of France. And it’s a monster.

With an output of 50 megawatts of electricity and 260 metric tons (286 tons) of steam per hour, the plant dwarves the country’s existing biomass power plants, which on average produce 3 MW, according to Dalkia. It shares a site with the existing Smurfit Kappa Cellulose du Pin paper mill in the small southwestern town of Facture, significantly simplifying the transmission of steam and electricity to the mill’s operations.

All the steam and some of the power produced at the CHP plant is sold to Smurfit Kappa and used on-site. “As the power plant is connected to the French grid through the mill connection, in fact, all the electricity is delivered to the mill,” says Mario Kuczynski, project manager for Dalkia. The excess power not used in the mill’s operations is sold to the national grid through Électricité de France. “This means that the pulp and paper mill is autonomous.”

That autonomous mill will now receive a guaranteed flow of steam for its operations with a contracted price 15 percent lower than the present internal cost, Kuczynski adds. The 20-year contract between the two partners will guarantee long-term efficiency and economic performance of Smurfit Kappa’s mill, not to mention almost half of Dalkia’s feedstock needs in bark and wood dust supplied by the mill. “It’s a wonderful win-win project for all parties,” he says.

Ins and Outs

The system—including the boiler, flue gas cleaning, complete automation and fuel handling systems—was delivered by Metso Corp., a global engineering and technology company serving the pulp and paper industries, with its hands in seemingly all the industries’ projects. At the heart of the operation is a bubbling fluidized-bed boiler, which is fed screened, chipped feedstock by a conveyor belt running from the 15,000-cubic-meter storage facility capable of holding up to three days worth of wood, according to Jouni Kinni, sales manager for Metso. “Thanks to a reclaimer of 17 meters long located at the bottom of the shelter, the biomass is continuously extracted and transferred to the boiler,” Kuczynski says. “It needs 300 meters of belt conveyors and two temporary silos in order to be 24/7 on full load capacity of the boiler.” The biomass—either delivered already chipped or chipped on-site—burns on a bed of sand in the boiler, he explains, comparing it to a hot tub, but with a scalding temperature of 850 degrees Celsius (1,562 degrees Fahrenheit).

The basic flue-gas-cleaning backhouse includes three rotating cylindrical modules. The conventional backhouse system allows the paper mill to also combust waste from the recycled cardboard it uses to make its products, Kinni says, citing it as the main reason the backhouse design was chosen for the application.

Smurfit Kappa Cellulose du Pin provides the CHP plant with 220,000 metric tons per year of its bark and wood dust, and another of the company’s paper mill locations, Comptoir du Pin, supplies 250,000 metric tons of branches and stumps, according to André Champarnaud, Cellulose du Pin mill manager. Another 80,000 metric tons will come from other sources such as construction sites and sawmills. In addition, debris from the Klaus storm that ripped through France in January 2009 will provide about 250,000 metric tons of wood feedstock for the system, offsetting its normal fuel needs, according to Dalkia.

Besides supplying wood waste for the biomass processes, Smurfit Kappa Cellulose du Pin also contributes its high-pressure steam to be converted into megawatts, Champarnaud says. “We sell bark and high-pressure steam and we buy medium- and low-pressure steam,” he explains, adding that the steam the mill buys back is used for drying paper and digesting the wood, and satisfies all of the mill’s steam needs. “All the steam we use in the paper mill is from Dalkia, so the cost of energy for the next 20 years is quite stable.”

Clearly, the setup results in a number of benefits, not the least of which are increased efficiency and reduced operating costs. The facility as a whole, including both paper and biomass processes, will be operating to optimum efficiency levels of 70 percent.

But besides that and stable energy costs, Champarnaud says Smurfit Kappa no longer burns natural gas to produce its steam, which comes with a substantial savings in carbon dioxide regulation compliance. In addition, the mill is no longer bothered with updating an existing biomass boiler and two turbines it had previously operated. “If we didn’t do this contract with Dalkia, we’d have to update again,” he says. Those updates, he adds in a thick French acccent, are a substantial investment for the company, “but we have stopped them and we have [no need] to renew them.”

The local community of Facture is not left out of the benefit circle, as the CHP plant brings tax revenue and about 90 jobs. The country of France itself will benefit from the project through the high-voltage green electricity and its contribution to reduce global climate change, Kuczynski says. Needless to say, all parties involved believe the enormous project will help realize significant benefits all through their 20-year contract.

Biomass in France

Smurfit Kappa Cellulose du Pin produces 500,000 tons per year of kraft liner and white top kraft liner. The facility is the only possible local industrial consumer for Dalkia’s plant, thus the decision to plot it within the mill’s existing infrastructure, Kuczynski says, emphasizing that the plant is located as close as possible to the paper process.

Use of such biomass CHP systems in France’s pulp and paper industry is beginning to expand, Champarnaud says, citing regulation from the European Commission. “We cannot say it is common, but it is developing.”

France has national renewable goals, too, and in 2009 committed to an overall objective of 23 percent of renewable electricity by 2020 within the context of the EU Climate Change Package. While the French incentives of tax amortization and preferential electricity purchase rates have attracted significant attention to the development of solar- and wind-powered energy, biomass is increasingly perceived as a more reliable and efficient alternative source, according to Jones Day, a law firm with an office in Paris. France is targeting an overall biomass power capacity of 2,300 MW by 2020, in order to increase its yearly biomass electricity production by a factor of five compared with its 2006 level. A generating capacity of 2,300 MW, running at an impossible 100 percent efficiency and 24/7 maintenance-free schedule, would generate more than 20,000 gigawatt hours (GWh) per year.

In 2008, 2,116 GWh of electricity were produced from biomass in France, with another 3,776 GWh from waste (separate from the biomass category), according to the International Energy Agency. Heat production from biomass that year was nonexistent, but 21,336 terajoules (TJ) were produced from waste. The most power that year was produced from nuclear sources at about 440,000 GWh, and the most heat came from gas at nearly 98,000 TJ. Wind produced more than 3,000 more GWh of power than biomass in 2008, and hydropower tipped the scales at more than 68,000 GWh. Neither source, however, was used to produce any heat that year, according to the IEA.

And as more biomass plants are established within the pulp and paper industries in France, those biomass figures will continue to grow. Projects similar in size to the Facture plant have been erected in Denmark, Finland and Sweden, but remain few in France, according to Gwen Jacobs, of the Energy Information Administration’s Country Energy Profiles Team. Smurfit Kappa does employ a similar system at a mill location in Sweden, but like both Kuczynski and Kinni, Champarnaud is quick to point out the massive and uncommon size of the Facture plant.

“This is a very big project we have in Facture,” he says. “Because it’s linked with a big mill, it is a project with the right return, and it is unique to have a paper mill with high conception of steam.” Dalkia, which invested about €130 million ($186 million) in the Facture application, is looking into the development of several other projects in France, but all will be substantially smaller, at around 7.5 MW, Kuczynski says. “This project of Facture really is a huge [and unique] one,” he says. “So as project manager I sincerely had a great pleasure to lead this power plant construction.”

Author: Lisa Gibson
Associate Editor, Biomass Power &Thermal
(701) 738-4952