Fresh or Recycled Fiber - Which Is Better?

The role our forests play in mitigating climate change is gaining greater attention. There has been a push to preserve our forests and use more recycled content in paper or packages. While it can be complicated to decide which is better—using virgin fiber or recycled fiber—there is an answer. It comes down to how that fiber will be used. And yes—in some cases, more recycled fiber means more GHG emissions.

The properties of wood fiber vary depending on whether it has been used, and how many times. A virgin wood fiber is longer and stronger than a recycled fiber. Each time fiber is recycled, it becomes shorter and weaker. For this reason, we always need to introduce some virgin fiber into paper products to maintain the strength and quality demanded of products by customers. A wood fiber can be used five to seven times to make pulp before reaching the end of its life.

Paper application matters

Optimizing the life of recovered fibers requires use in the most efficient applications. For instance, higherquality paper products requiring brightness and low contamination should run more efficiently when using virgin fiber. Using recycled fibers for these applications drives more processing with adverse impacts on emissions, waste generation, and recovered fiber yield.

This concept isn’t new. In 2013, Sappi published an article detailing our internal analysis of the Somerset Mill and the impact on GHG emissions when using recycled fiber. More recently, Massachusetts Institute of Technology (MIT) conducted research into the circular flow of fiber across several paper sectors, and the result may surprise you.

MIT’s case study

The MIT Dynamic Fiber Flow model combines systems dynamics with lifecycle assessment to understand the systemic effects of changes to paper recovery and recovered paper utilization across the value chain. This complex model was used to quantify system responses based on industry technology and data, using market conditions in 2017 as the baseline period.

In the case study most applicable to fine paper, MIT found that increasing the recycled content of printing and writing freesheet paper to 15 percent, freesheet producers would require 1.1 million tons more recovered paper. This presents a challenge because sources of high-grade pulp substitutes and high-grade deinked pulp are limited. This is driven by the closure of roughly 82 percent of deinking facilities in North America over the last 20 years. Although fiber moves through the paper industry, it cannot be infinitely recycled and virgin fiber must enter the cycle in order to produce recovered fiber. Nearly 90 percent of recovered paper is used in grades like newsprint, containerboard, tissue, or certain packaging and board grades. If we divert from these uses to printing and writing freesheets, we begin to impact the wider paper industry.

In this case, the study predicted that the recovered fiber needed to move from 7.8 percent to 15 percent recovered content in printing and writing papers would be pulled from the tissue manufacturing stream. This would tip the tissue sector more toward virgin pulp. Tissue products are not typically recovered or recycled. Thus, virgin fiber would bypass the recycling process entirely and enter the waste stream after only one use. The loss here is twofold: the waste of harvested fiber after one use and the loss of its remaining usable life.

The immediate implication of this scenario is simple—more virgin fiber would be required for the tissue sector. Less obvious is the increase in greenhouse gas emissions (GHG). According to MIT’s model, increasing recycled content in printing and writing grades would, due to fiber flow shifts throughout the economy, reduce carbon-neutral biomass energy consumption by approximately 30 million gigajoules. In addition, it would increase the use of fossil fuel-based energy consumption by approximately 32 million gigajoules, thereby increasing overall GHG emissions.

Conserve, recover, reuse

It’s critically important that we conserve, recover, and reuse our natural resources as much as possible. While most processes will require some virgin fiber to meet specifications, we can sustainably integrate recovered fiber at key points to maximize its reuse and minimize environmental impact. Recovered fiber is best used in products that don’t require significant brightening and cleaning; those processes result in a larger manufacturing environmental footprint. Shifting to higher recycled content across the board is not the best way to use our natural resources. We get to choose how we use our resources, and our choices impact not only our lives, but our planet. We must choose wisely.