Features Research & Innovation
It takes energy to run a mill

IT IS NO SECRET that energy costs are high in Canada, but the hard truth of how high can be shocking: The Canadian industry is operating with the second highest energy costs in the world. With this being the case, mills are scrambling to find ways to reduce energy costs. Such was the emphasis of presenters at Thursday afternoon’s session on energy.

Nazmir Bundalli, president of Kemengo Technology Inc., spoke about a technology developed at BC Research Corp., and later transferred to private enterprise. In Development of the ‘moving hole,’ Bundalli’s aim is to dispel the idea that hog fuel boilers must be shaped with negative slope. He said that this approach to design shows a lack of understanding of design and geometry.

His concept is called a mini-feeder. Although it uses a very simple design principle, the technology is proven. “The concept of mass-flow design and the mini-feeder has been shown to work,” he said, referring to an installation the company has made in northern BC.

Jennifer Fraser, Enron Capital and Trade Resources, said that the industry uses “in excess of 21 megajoules (MJ) of energy per dollar value of shipments.” Pulp and paper is the single largest industrial user, accounting for 11% of energy use in Canada. Enron, a Houston-based company, reported sales of $30 billion (US) in 1998, and owns two paper mills in Canada: Repap and Papier Masson Ltd.

One of the main problems the industry faces, co-author Craig Breslau, also of Enron, pointed out, is that energy prices are often high when commodity prices are low. This problem becomes all too apparent when, for example, newsprint prices are falling, while the cost of natural gas is rising. The solution, he said, is to hedge against fluctuations, much in the same way paper producers hedge against currency fluctuations. In essence, energy costs are indexed to the selling price of the commodity.

“You can lock in at a price and take out the uncertainty,” Breslau said, which is the opposite of the speculative way many companies are now doing business. “Whenever newsprint prices are up you pay more for natural gas, [and conversely], when newsprint prices are down natural gas prices will be lower.”

Cogeneration may prove to be saving grace. With deregulation soon happening, in Ontario in 2000 and in Alberta in 2001, paper producers will have more control of energy costs.

Another opportunity for reducing energy costs is to retrofit recovery boilers, a task particularly suitable for older paper mills. This was the main point of Doug Albertson’s paper, Recovery boiler retrofit with fluidized bed technology. He explained how his company, Energy Products of Idaho, retrofitted a black liquor recovery boiler at a paper mill. It wanted to eliminate its pulping process and switch to 100% recycled fibre. One of the main benefits of a fluidized bed retrofit is it allows combustion of paper sludge as an option to landfill. The retrofit was done with the Cluster Rule in mind.

With a slight modification, however, a fluidized bed retrofit allows a readily available source of fuel to be burned: tires. Because burning tires generates more energy than coal — 14 000 BTU/lb versus 12 000/lb — its use as a fuel source is undeniable. As well, doing so would not only benefit individual mills, but also clean up the environment. As for the emissions generated from burning tires, which contain 1.2% sulphur, Albertson pointed out that “the calcium in the recycled paper tends to neutralize or reduce SO2 emissions resulting from burning tires.”

“It is important to take a holistic view of the dryer section performance,” said Wesley Martz of The Johnson Corp. Martz explained in detail each of the four steps required to “improve the operation and performance of the dryer section.” These steps are as follows: a steam flow analysis, syphon selection and design, steam and condensate analysis, and energy balance analysis.

He reminded audience members of a key fact: “Condensate removal and air systems account for more than 65% of the variables that affect the overall performance of the dryer section.”