Renewable energy helps pulp and paper mills reduce carbon footprint, increase energy independence
APP is generating energy from what the paper industry has long considered waste.
The company’s newest innovation is technology to generate methane from wastewater, and to recycle the gas as a fuel to power production.
The mills are currently experimenting with various sources of non-fossil fuel to produce power; methane gas from anaerobic water treatment process, waste water treatment sludge, black liquor and empty fruit benches of palm fruits. These efforts contribute to the goal of breaking a reliance on fossil fuels like coal or natural gas.
For example, the Indah Kiat Perawang and Lontar Papyrus mills now meet about two-thirds of their energy needs by reprocessing byproducts into black liquor which is considered renewable. In fact, Indah Kiat Tangerang is using waste heat from a sophisticated gas turbine power generation unit to reduce its use of coal to process steam. The Indah Kiat Perawang mill is now self-sufficient in terms of energy.
In addition to the Indah Kiat Serang mill, plans are advancing at two other APP mills to use the methane gas from the wastewater treatment plant sludge to produce energy. This initiative is a part of the Clean Development Mechanism Project (CDM), a scheme developed by the United Nations to assist developing nations in developing environmentally friendly technologies.
Just as each APP mill has unique energy needs, each is finding distinctive ways to reduce its carbon footprint and achieve energy independence. For example:
- Black liquor is the alternative fuel of choice at Lontar Papyrus mill (LP) in Jambi Province, Sumatra, where the mill meets nearly 60 percent of its energy needs by recycling the process-generated byproduct. Though black liquor is widely used throughout the pulp and paper industry, few mills are as resourceful with it as LP, where quality control employee Ira Galih oversees its production. She says that as a “side effect” of the black-liquor condensation process, a chemical-laden substance called “foul condensate” is produced. “The foul condensate would create a heavy load if we sent it directly to our wastewater treatment system,” Galih says. “Instead, we use another process that reduces its chemical content by combining it with steam. During this process, the chemical contents turn into gas that can be burned as fuel. The remaining liquid becomes a clean condensate with far less toxic chemical properties, and undergoes further environmentally-friendly processing for it to be safely released into the environment.”
- In addition to black liquor, around 20 percent of the LP energy mix comes from recycled bark and wood waste. Although Lontar Papyrus has the ability to tap into electricity supplied by the Indonesia national power company PLN if circumstances require, the paper mill hasn’t drawn any PLN electricity since 2008.
- Indah Kiat Tangerang mill, about 30 kilometers west of central Jakarta, doesn’t make a lot of noise about its energy usage. And that’s exactly what the paper mill intended. Since 1996, the mill has been using a sophisticated gas-turbine system to generate power that exhausts into a waste heat boiler to produce additional steam. As a result, Indah Kiat Tangerang uses its five diesel-engine power generating units for standby purposes only, greatly reducing the nuisance of noise in the nearby community.
- Pindo Deli operates two mills at two separate sites both in Karawang, West Java. While plans are underway for using renewable energy sources, such as sludge from the wastewater treatment plant, Pindo Deli is taking a variety of in-house measures to increase the mills’ energy independence, including limiting the amount of hours that air conditioning is operated in the main offices each day.