How International Paper Cuts Greenhouse Gas Emissions

The American Forest and Paper Association (AF&PA) has set a goal to reduce greenhouse gas emissions from the forest products industry by 15 percent by 2020, but one of the association’s members, International Paper, is aiming for a more ambitious target: 20 percent by 2020. And the pulp and paper company is making progress towards its objective, cutting companywide emissions by 5.8 percent last year, according to International Paper’s recently released sustainability report.

The 5.8 percent figure is an aggregate of increases and drops in the company’s emissions in two different sectors:  Emissions from burning fossil fuels to power the company’s mills fell 7 percent in 2013, while emissions from electricity purchased from utilities climbed 4 percent from the company’s 2010 baseline and 8 percent year-over-year.

The bulk of International Paper’s emissions reductions were achieved at the company’s 41 paper mills, which are responsible for more than 95 percent of the company’s total energy use and 90 percent of the company’s fossil fuel consumption, according to the sustainability report. But about 72 percent of the mills’ energy actually comes from a recovered waste product, rather than a fossil fuel. When a tree goes through the mills’ pulping process, its wood fibers are separated from the natural glues and sugars that previously held the tree together. The fibers will eventually be made into paper products, while the leftover glues and sugars become a biofuel that is burned to produce energy for the mill.

Using waste for biomass

Biomass is considered a renewable fuel because its energy came from the sun and it can be re-grown in a relatively short period of time, according to the Union of Concerned Scientists. Biomass proponents say that it is also a carbon-neutral fuel: Burning wood for energy releases stored carbon that trees would have eventually given off as part of their natural death and decaying process. In this vein, International Paper said it emitted approximately 34 million metric tons of carbon-neutral emissions from biomass in 2013.

Biomass is a controversial energy source, however: Its critics charge that it competes for agricultural land with food production and argue that any fuel that generates pollution cannot be considered carbon neutral.

But International Paper is using a biomass derived from a waste product that would otherwise have been discarded – clearly a more sustainable solution than throwing the wood residue in the landfill or using crop land to grow fuel. And despite the debate on carbon neutrality, the fact remains that biomass is low-carbon and cleaner than fossil fuels. In fact, the Union of Concerned Scientists considers biomass from sustainably harvested wood and forest residues – like the kind International Paper uses – to be a “beneficial biomass” that can “reduce overall carbon emissions and provide other benefits.”

Since recovered biomass accounts for approximately 72 percent of the mills’ energy needs, the company purchases fuel and electricity to power the remaining 28 percent of the facilities’ energy demands. To achieve emissions reductions in this area, International Paper has improved energy efficiency and switched away from coal and fuel oil in its mills.

“Between 2010 and 2013, we invested about $380 million in energy efficiency and fuel flexibility,” said Paul Tucker, the company’s manager of energy and chemical recovery solutions.

Emissions reductions through thermal energy

To make the most dramatic emissions reductions in its mills, the company focused on its use and reuse of thermal energy, which accounts for more than 80 percent of a mill’s energy demand, Tucker said. The process to make pulp and paper requires a huge amount of thermal energy to heat and evaporate water, he said.

For example, International Paper’s Russian mill installed a 25-megawatt combined heat and power system – equipment that simultaneously generates electricity and process steam more efficiently than stand-alone power generation would. The new system produces more than 180 million kilowatt-hours of electricity annually – enough electricity to power 16,000 U.S. homes – as well as steam to fuel the facility’s manufacturing processes, the company said in its report.

At its mill in Maysville, Ky., International Paper set up a paper machine heat recovery system, which captures hot exhaust gas from the paper-drying process and uses it to heat water. The project will reduce the facility’s need for coal-powered steam by 12,000 tons of coal per year – the equivalent amount of coal needed to fuel 100 railcars annually, according to the report.

The paper and pulp company has also been replacing the coal and fuel oil used to produce its mills’ thermal energy with cleaner-burning energy sources, including natural gas and biomass. While natural gas is still a fossil fuel, the report noted, it releases half the amount of carbon dioxide emissions that coal does.

Natural gas may be a reliable energy source for some of International Paper’s U.S. mills, since natural gas is abundant and economical in many parts of the country, but it is not an option in some parts of the world, Tucker said. For example, purchasing natural gas was not feasible for the company’s mill in Brazil; there are not many natural gas reserves in Brazil, so most natural gas comes from other countries, Tucker said. The company’s mill already had a Eucalyptus plantation, so mill employees dedicated a portion of the plantation to grow biomass fuel. International Paper put in a new biomass boiler at the facility, which converted nearly 200,000 tons of fossil-fuel-based emissions into cleaner-burning biomass emissions.

Why chose biomass over other renewable energy sources like solar or wind? Those types of renewables are better suited for providing electricity, Tucker said; a paper mill requires vast supplies of thermal energy, and suitable sources of thermal energy include natural gas and biomass. International Paper is looking into opportunities for solar and wind projects to serve the electrical needs at its facilities and has just installed solar array at a bulk packaging plant in Exeter, Calif., that will produce about a megawatt of electricity, Tucker said.

In addition to decreasing the company’s carbon footprint, reducing the company’s demand for coal and oil led to a significant drop in its emissions of harmful air pollutants. Since 2010, International Paper has cut sulfur dioxide emissions by 25 percent and nitrogen oxides emissions by 10 percent – for an overall reduction of 14 percent in what the Environmental Protection Agency (EPA) refers to as the "criteria pollutants.”

How will International Paper achieve its ultimate goal?

International Paper – and the pulp and paper industry as a whole – faces many challenges as it strives to slash its carbon emissions further. One of these obstacles is an uncertain regulatory landscape, Tucker said: For example, the EPA keeps changing its “final” rules regulating industrial boilers – which makes it difficult to undertake the 2- to 3-year planning process of investing in new boiler equipment.

Paper and pulp makers – and all manufacturers – also must consider the long-term viability of their facilities -- another challenge when planning for energy efficiency and emissions reductions, Tucker said. It can be risky for a company to propose long-term investments in energy efficiency at a facility whose markets may shrink or change, he said.

There is also the simple fact that once a company makes initial, deep energy reductions at a facility, it becomes difficult to squeeze out any more energy savings, Tucker noted. But International Paper will continue its current course, Tucker continued, looking for more opportunities to improve its facilities’ energy efficiency and replace its coal and fuel oil with more sustainable energy sources.

“We’ll keep peeling back the layers of the proverbial onion in trying to make ourselves more efficient,” he said.

Image credit: International Paper

Passionate about both writing and sustainability, Alexis Petru is freelance journalist based in the San Francisco Bay Area whose work has appeared on Earth911, Huffington Post and Patch.com. Prior to working as a writer, she coordinated environmental programs for Bay Area cities and counties. Connect with Alexis on Twitter at @alexispetru