54 POWERSPECTRUM

Clean energy – smaller footprint

The boiler project for Bollnäs Energi’s co-generation plant in Sweden started out like most projects do. Feasibility studies, tenders, bid evaluation, technical evaluation, contract award to the winning suppliers.

The project also progressed better-than-normal – from the start of piling work in April 2010, to the mobilization on-site by the boiler supplier in September. Right up to November 9th. Then the project “hit some bumps” according to ANDRITZ Project Manager Christian Lackinger.

A cogen plant designed to minimize its carbon footprint and also keep tonnes of waste out of landfill. Not bad. The fact that it started up on time and has performed beautifully is testament to the hard work and great cooperation of the project team. This boiler project had some im-mense challenges – including harsh winter weather and financial insolvency – that could have led to a very different result.

How it overcame those “bumps,” regained its momentum, and ended successfully is a story worth repeating.

“Totally the wrong winter”When Torbjörn Nilsson woke up the morn-ing of November 10th, he knew it was going to be a challenging day. “The skies turned slate gray,” Nilsson recalls, “temperatures plunged, and snow started falling.”

What Nilsson could not know at the time was that the challenge would last for weeks.

In contrast to previous mild winters, the one in 2010 quickly became brutal. “Totally the wrong winter to build a power plant,” Nilsson says.

Driving fossil fuels to zeroThe driving force for Bollnäs Energi’s proj-ect, Managing Director Mikael Strandberg explains, was to reduce the use of fossil fuels to zero. “Our Board set the goal to accomplish this by 2015,” he says. “With this new boiler, we have reduced fossil fuel consumption from 12-14% down to 0.9%. At another site, we are building a small (3 MW) biomass boiler. After that, we hope to be at zero.”

Säversta was built in 1983 as a district heat-ing plant with two 12 MW boilers burning primarily RDF (refuse-derived fuels such as household waste). There was no turbine-generator. “In Sweden, you pay a tax for waste incineration, and you get credits for Green energy production,” Strandberg says. So, the new plant is a waste-fired cogeneration plant providing heat to 5,500 homes in the commune and selling electricity to the grid.

“We have incinerated RDF from the very beginning,” Strandberg says. “We are prob-ably among the first to fire RDF in a fluidized bed boiler.” Fredrik Englund, Bollnäs Energi’s Assistant Production Manager, explains that Bollnäs Energi’s district heating system con-sists of three networks. The largest network uses mainly RDF, while the two smaller net-works are heated using biofuels.

“Our biggest investment”“This was our biggest investment ever – SEK 420 million (EUR 50 million),” says Strandberg. “Everyone in the community has been inter-ested in the project.”

The original contract for the boiler (including pressure parts, erection of steel structures, instrumentation, and auxiliary systems) was awarded to Austrian Energy & Environment (AE&E) at the end of 2009 (now ANDRITZ Energy & Environment). The plant was rat-ed at a thermal capacity of 28 MW and 7 MW electricity. “We knew AE&E,” Strandberg says. “They had a good reputation for fluid-ized bed boilers and installed a biomass boiler nearby at Söderhamn in 2005 which was operating quite well.”

“During the evaluation, we asked questions and they listened,” Nilsson remembers. “We had good discussions about availability and technical details. AE&E’s proposal was more interesting technically. Their materials handling

approach was totally different and superior. The steam data was also better.” The layout impressed Strandberg. “We have very limited space, as this boiler is surrounded on three sides by existing plant,” he says. “We needed to have a path through the boiler building for a lorry to pass (due to the location of a magnetic separation system). AE&E solved the layout challenges in a quite smart way.”

Smart layout. Boiler plant sandwiched into existing building on three sides

Ash removal from the four hoppers under the horizontal pass with superheaters in place

Off to a good startEarly in 2010, Bollnäs Energi acquired a turbine-generator and dry gas cleaning sys-tem while site preparation began. Existing waste management equipment (jaw crusher, augers, conveyors, and silos) were adapted. Lackinger and his team mobilized to the site in September after the foundation work was done. The boiler’s front wall was erected in

We have very limited space, as this boiler is surrounded on three sides by existing plant. ANDRITZ solved the layout chal-lenges in a quite smart way. Mikael Strandberg, Managing Director at Bollnäs Energi

“”

54 POWERSPECTRUM

Clean energy – smaller footprint

The boiler project for Bollnäs Energi’s co-generation plant in Sweden started out like most projects do. Feasibility studies, tenders, bid evaluation, technical evaluation, contract award to the winning suppliers.

The project also progressed better-than-normal – from the start of piling work in April 2010, to the mobilization on-site by the boiler supplier in September. Right up to November 9th. Then the project “hit some bumps” according to ANDRITZ Project Manager Christian Lackinger.

A cogen plant designed to minimize its carbon footprint and also keep tonnes of waste out of landfill. Not bad. The fact that it started up on time and has performed beautifully is testament to the hard work and great cooperation of the project team. This boiler project had some im-mense challenges – including harsh winter weather and financial insolvency – that could have led to a very different result.

How it overcame those “bumps,” regained its momentum, and ended successfully is a story worth repeating.

“Totally the wrong winter”When Torbjörn Nilsson woke up the morn-ing of November 10th, he knew it was going to be a challenging day. “The skies turned slate gray,” Nilsson recalls, “temperatures plunged, and snow started falling.”

What Nilsson could not know at the time was that the challenge would last for weeks.

In contrast to previous mild winters, the one in 2010 quickly became brutal. “Totally the wrong winter to build a power plant,” Nilsson says.

Driving fossil fuels to zeroThe driving force for Bollnäs Energi’s proj-ect, Managing Director Mikael Strandberg explains, was to reduce the use of fossil fuels to zero. “Our Board set the goal to accomplish this by 2015,” he says. “With this new boiler, we have reduced fossil fuel consumption from 12-14% down to 0.9%. At another site, we are building a small (3 MW) biomass boiler. After that, we hope to be at zero.”

Säversta was built in 1983 as a district heat-ing plant with two 12 MW boilers burning primarily RDF (refuse-derived fuels such as household waste). There was no turbine-generator. “In Sweden, you pay a tax for waste incineration, and you get credits for Green energy production,” Strandberg says. So, the new plant is a waste-fired cogeneration plant providing heat to 5,500 homes in the commune and selling electricity to the grid.

“We have incinerated RDF from the very beginning,” Strandberg says. “We are prob-ably among the first to fire RDF in a fluidized bed boiler.” Fredrik Englund, Bollnäs Energi’s Assistant Production Manager, explains that Bollnäs Energi’s district heating system con-sists of three networks. The largest network uses mainly RDF, while the two smaller net-works are heated using biofuels.

“Our biggest investment”“This was our biggest investment ever – SEK 420 million (EUR 50 million),” says Strandberg. “Everyone in the community has been inter-ested in the project.”

The original contract for the boiler (including pressure parts, erection of steel structures, instrumentation, and auxiliary systems) was awarded to Austrian Energy & Environment (AE&E) at the end of 2009 (now ANDRITZ Energy & Environment). The plant was rat-ed at a thermal capacity of 28 MW and 7 MW electricity. “We knew AE&E,” Strandberg says. “They had a good reputation for fluid-ized bed boilers and installed a biomass boiler nearby at Söderhamn in 2005 which was operating quite well.”

“During the evaluation, we asked questions and they listened,” Nilsson remembers. “We had good discussions about availability and technical details. AE&E’s proposal was more interesting technically. Their materials handling

approach was totally different and superior. The steam data was also better.” The layout impressed Strandberg. “We have very limited space, as this boiler is surrounded on three sides by existing plant,” he says. “We needed to have a path through the boiler building for a lorry to pass (due to the location of a magnetic separation system). AE&E solved the layout challenges in a quite smart way.”

Smart layout. Boiler plant sandwiched into existing building on three sides

Ash removal from the four hoppers under the horizontal pass with superheaters in place

Off to a good startEarly in 2010, Bollnäs Energi acquired a turbine-generator and dry gas cleaning sys-tem while site preparation began. Existing waste management equipment (jaw crusher, augers, conveyors, and silos) were adapted. Lackinger and his team mobilized to the site in September after the foundation work was done. The boiler’s front wall was erected in

We have very limited space, as this boiler is surrounded on three sides by existing plant. ANDRITZ solved the layout chal-lenges in a quite smart way. Mikael Strandberg, Managing Director at Bollnäs Energi

“”

54 POWERSPECTRUM

Clean energy – smaller footprint

The boiler project for Bollnäs Energi’s co-generation plant in Sweden started out like most projects do. Feasibility studies, tenders, bid evaluation, technical evaluation, contract award to the winning suppliers.

The project also progressed better-than-normal – from the start of piling work in April 2010, to the mobilization on-site by the boiler supplier in September. Right up to November 9th. Then the project “hit some bumps” according to ANDRITZ Project Manager Christian Lackinger.

A cogen plant designed to minimize its carbon footprint and also keep tonnes of waste out of landfill. Not bad. The fact that it started up on time and has performed beautifully is testament to the hard work and great cooperation of the project team. This boiler project had some im-mense challenges – including harsh winter weather and financial insolvency – that could have led to a very different result.

How it overcame those “bumps,” regained its momentum, and ended successfully is a story worth repeating.

“Totally the wrong winter”When Torbjörn Nilsson woke up the morn-ing of November 10th, he knew it was going to be a challenging day. “The skies turned slate gray,” Nilsson recalls, “temperatures plunged, and snow started falling.”

What Nilsson could not know at the time was that the challenge would last for weeks.

In contrast to previous mild winters, the one in 2010 quickly became brutal. “Totally the wrong winter to build a power plant,” Nilsson says.

Driving fossil fuels to zeroThe driving force for Bollnäs Energi’s proj-ect, Managing Director Mikael Strandberg explains, was to reduce the use of fossil fuels to zero. “Our Board set the goal to accomplish this by 2015,” he says. “With this new boiler, we have reduced fossil fuel consumption from 12-14% down to 0.9%. At another site, we are building a small (3 MW) biomass boiler. After that, we hope to be at zero.”

Säversta was built in 1983 as a district heat-ing plant with two 12 MW boilers burning primarily RDF (refuse-derived fuels such as household waste). There was no turbine-generator. “In Sweden, you pay a tax for waste incineration, and you get credits for Green energy production,” Strandberg says. So, the new plant is a waste-fired cogeneration plant providing heat to 5,500 homes in the commune and selling electricity to the grid.

“We have incinerated RDF from the very beginning,” Strandberg says. “We are prob-ably among the first to fire RDF in a fluidized bed boiler.” Fredrik Englund, Bollnäs Energi’s Assistant Production Manager, explains that Bollnäs Energi’s district heating system con-sists of three networks. The largest network uses mainly RDF, while the two smaller net-works are heated using biofuels.

“Our biggest investment”“This was our biggest investment ever – SEK 420 million (EUR 50 million),” says Strandberg. “Everyone in the community has been inter-ested in the project.”

The original contract for the boiler (including pressure parts, erection of steel structures, instrumentation, and auxiliary systems) was awarded to Austrian Energy & Environment (AE&E) at the end of 2009 (now ANDRITZ Energy & Environment). The plant was rat-ed at a thermal capacity of 28 MW and 7 MW electricity. “We knew AE&E,” Strandberg says. “They had a good reputation for fluid-ized bed boilers and installed a biomass boiler nearby at Söderhamn in 2005 which was operating quite well.”

“During the evaluation, we asked questions and they listened,” Nilsson remembers. “We had good discussions about availability and technical details. AE&E’s proposal was more interesting technically. Their materials handling

approach was totally different and superior. The steam data was also better.” The layout impressed Strandberg. “We have very limited space, as this boiler is surrounded on three sides by existing plant,” he says. “We needed to have a path through the boiler building for a lorry to pass (due to the location of a magnetic separation system). AE&E solved the layout challenges in a quite smart way.”

Smart layout. Boiler plant sandwiched into existing building on three sides

Ash removal from the four hoppers under the horizontal pass with superheaters in place

Off to a good startEarly in 2010, Bollnäs Energi acquired a turbine-generator and dry gas cleaning sys-tem while site preparation began. Existing waste management equipment (jaw crusher, augers, conveyors, and silos) were adapted. Lackinger and his team mobilized to the site in September after the foundation work was done. The boiler’s front wall was erected in

We have very limited space, as this boiler is surrounded on three sides by existing plant. ANDRITZ solved the layout chal-lenges in a quite smart way. Mikael Strandberg, Managing Director at Bollnäs Energi

“”

76 POWERSPECTRUM

late October. “We were off to a good start and making very good progress with erection until mid-November,” he says.

Then winter came overnight“The workers had to remove a tremendous amount of snow each day just to begin work, and the temperatures were extremely cold,” Lackinger said. “The good news is that since this boiler was using waste fuels, we were using normal steels that could be welded in the low temperatures. The bad news is that someone had to be outside to weld it.” Fantastic workBitter cold days (-20° C was common). “The Polish welders and erectors hired by AE&E showed a lot of determination,” Nilsson says. “They are very dedicated and tough workers. Even with the terribly cold working condi-tions, out of 1,816 welds that were x-rayed, there were only two minor corrections to be made. Fantastic!”

Insolvency creates another hurdleAE&E was the largest subsidiary of A-Tec Industries AG of Austria. A-Tec was forced to file for bankruptcy in the fall of 2010. “Rumors began to circulate in October that A-Tec was in trouble, but that AE&E would not be affected,” Strandberg says. “Then we got word that AE&E was also forced to file for bankruptcy.”

“It was a stressful time for all of us,” Lackinger admits. “AE&E was split apart and offered for sale to different buyers. I got phone calls of all our subcontractors notifying me they were stopping deliveries and wanting to see how they would get paid.”

On November 29th there was a work stop-page by the Polish erection workers. Nilsson recalls that at that time a boiler bank was hanging in chains from a crane lift and the boiler structure was not roofed in. “We were scurrying to develop a Plan B, but we knew it would be expensive. But the work stoppage lasted less than two days and the problem was solved when ANDRITZ came into the picture. There was a big sigh of relief on our part.”

ANDRITZ purchased the part of AE&E re-sponsible for boilers, air pollution control equipment, and boiler services and reas-sured Bollnäs Energi that the project would continue. “We were quite lucky to become part of the ANDRITZ Group,” Lackinger says.

Back on trackThe boiler was commissioned in June 2011 and by November the first firing of refuse-derived fuel occurred. Lackinger handed over the keys to Nilsson, Englund, and the team from Bollnäs Energi before Christmas 2011, one week ahead of the original schedule.

The environmental permit for the facility allows the incineration of 80,000 tonnes of waste per year. About 60,000 tonnes are supplied by Gävleborg county. The ANDRITZ boiler provides significant flexibility in fuels (waste, biofuel, and peat can all be burned in the boiler) and in load range (100% down to 40% of load with full steam parameters). In 2012 Bollnäs Energi plans to supply 155 GWh of heat and 32 GWh of electricity.

Performed beautifully“During the summer we inspected the boiler internals,” Englund says. “There were some places we expected to see deposits or plug-ging, but we did not find so much. When we went in to clean the superheater tubes, the original color was still on the pipes.”

“This is impressive since we had consider-able discussion at the start of the project whether we should invest in sootblowers,” Nilsson recalls. “AE&E recommended a piston-driven rapping system for the hori-zontal pass which we had not seen before and shot cleaning for the economizers. The systems have performed beautifully and save us money.”

“With the combination of penalties and in-centives in Sweden, if you have low NOx emissions and high energy production, you can earn money,” Strandberg says. “High emissions cost us dearly. We intend to earn money with this boiler.”

“With the fluidized bed,” Nilsson explains, “we are running at about 0-1 mg/m3 of CO. Our permitted level is 50. We can optimize NOx

further by allowing a slight increase in CO.”

Since the start-up, Bollnäs Energi has en-tertained visitors from Australia, Hong Kong, Canada, and the USA to see the installation. “It is very nice to show them around,” Nilsson says. “We are very proud of what we have done here.”

The Säversta plant has incinerated refuse-derived fuels (RDF) – household waste – from its start in 1983. Environmental permits allow the inciner-ation of 80,000 tonnes of waste per year, reducing considerably the amount going to local landfills.

From left to right: Lackinger of ANDRITZ with Nilsson, Strandberg, and Englund of Bollnas Energi.

76 POWERSPECTRUM

late October. “We were off to a good start and making very good progress with erection until mid-November,” he says.

Then winter came overnight“The workers had to remove a tremendous amount of snow each day just to begin work, and the temperatures were extremely cold,” Lackinger said. “The good news is that since this boiler was using waste fuels, we were using normal steels that could be welded in the low temperatures. The bad news is that someone had to be outside to weld it.” Fantastic workBitter cold days (-20° C was common). “The Polish welders and erectors hired by AE&E showed a lot of determination,” Nilsson says. “They are very dedicated and tough workers. Even with the terribly cold working condi-tions, out of 1,816 welds that were x-rayed, there were only two minor corrections to be made. Fantastic!”

Insolvency creates another hurdleAE&E was the largest subsidiary of A-Tec Industries AG of Austria. A-Tec was forced to file for bankruptcy in the fall of 2010. “Rumors began to circulate in October that A-Tec was in trouble, but that AE&E would not be affected,” Strandberg says. “Then we got word that AE&E was also forced to file for bankruptcy.”

“It was a stressful time for all of us,” Lackinger admits. “AE&E was split apart and offered for sale to different buyers. I got phone calls of all our subcontractors notifying me they were stopping deliveries and wanting to see how they would get paid.”

On November 29th there was a work stop-page by the Polish erection workers. Nilsson recalls that at that time a boiler bank was hanging in chains from a crane lift and the boiler structure was not roofed in. “We were scurrying to develop a Plan B, but we knew it would be expensive. But the work stoppage lasted less than two days and the problem was solved when ANDRITZ came into the picture. There was a big sigh of relief on our part.”

ANDRITZ purchased the part of AE&E re-sponsible for boilers, air pollution control equipment, and boiler services and reas-sured Bollnäs Energi that the project would continue. “We were quite lucky to become part of the ANDRITZ Group,” Lackinger says.

Back on trackThe boiler was commissioned in June 2011 and by November the first firing of refuse-derived fuel occurred. Lackinger handed over the keys to Nilsson, Englund, and the team from Bollnäs Energi before Christmas 2011, one week ahead of the original schedule.

The environmental permit for the facility allows the incineration of 80,000 tonnes of waste per year. About 60,000 tonnes are supplied by Gävleborg county. The ANDRITZ boiler provides significant flexibility in fuels (waste, biofuel, and peat can all be burned in the boiler) and in load range (100% down to 40% of load with full steam parameters). In 2012 Bollnäs Energi plans to supply 155 GWh of heat and 32 GWh of electricity.

Performed beautifully“During the summer we inspected the boiler internals,” Englund says. “There were some places we expected to see deposits or plug-ging, but we did not find so much. When we went in to clean the superheater tubes, the original color was still on the pipes.”

“This is impressive since we had consider-able discussion at the start of the project whether we should invest in sootblowers,” Nilsson recalls. “AE&E recommended a piston-driven rapping system for the hori-zontal pass which we had not seen before and shot cleaning for the economizers. The systems have performed beautifully and save us money.”

“With the combination of penalties and in-centives in Sweden, if you have low NOx emissions and high energy production, you can earn money,” Strandberg says. “High emissions cost us dearly. We intend to earn money with this boiler.”

“With the fluidized bed,” Nilsson explains, “we are running at about 0-1 mg/m3 of CO. Our permitted level is 50. We can optimize NOx

further by allowing a slight increase in CO.”

Since the start-up, Bollnäs Energi has en-tertained visitors from Australia, Hong Kong, Canada, and the USA to see the installation. “It is very nice to show them around,” Nilsson says. “We are very proud of what we have done here.”

The Säversta plant has incinerated refuse-derived fuels (RDF) – household waste – from its start in 1983. Environmental permits allow the inciner-ation of 80,000 tonnes of waste per year, reducing considerably the amount going to local landfills.

From left to right: Lackinger of ANDRITZ with Nilsson, Strandberg, and Englund of Bollnas Energi.