Date of Award

5-2013

Level of Access

Campus-Only Thesis

Degree Name

Master of Science (MS)

Department

Biological Engineering

Advisor

Doug Bousfield

Second Committee Member

Darrell Donahue

Third Committee Member

Barbara Hermann

Abstract

Increasing awareness of the environmental impacts associated with industrialized processes has led to a growing demand for sustainably produced products. The pulp and paper industry has several environmental implications due to operations that consume large amounts of energy, water, and chemicals. Substantial improvements have been made to address the harmful effects of the bleaching process, including the replacement of traditional chlorine bleaching with elemental chlorine free (ECF) bleaching in pulp mills. However, clear methods to assess process changes in terms of their net environmental impact are not well developed in the pulp and paper industry. Life Cycle Assessment (LCA) provides a comprehensive methodology to quantify the environmental impacts of a product, process, or system and can be used to better understand the implications of new technologies, process improvements, and product design and development.

This study uses LCA to evaluate the environmental performance of packaging paper made with sulfite pulp at an integrated pulp and paper facility and compares three pulp bleaching alternatives, including chlorine bleached, ECF bleached, and unbleached pulp for one short ton of packaging paper with an end use in food service applications. The analysis was based on data from operations at Twin Rivers Paper Company, including a pulp mill in Edmundston, New Brunswick and a paper mill in Madawaska, Maine. The impact assessment was performed according to the IMPACT 2002+ methodology and using LCA software, SimaPro 7. An uncertainty analysis, sensitivity analysis, and data validation were completed to facilitate interpretation of the results.

The impact assessment results identified the consumption of energy, namely electricity, as the primary source of environmental impacts for the studied product system. Based on normalization of the results, the overall environmental performance can be most significantly improved by focusing on areas that influence respiratory inorganics, global warming, and nonrenewable energy and specifically minimizing emissions of S02 and NOx and the consumption of natural gas and coal for power generation. Any effort to reduce the demand for electricity would largely improve the impact on human health, climate change, and resources.

Comparison of the pulp bleaching alternatives illustrated that unbleached packaging paper has the lowest environmental impacts for all of the evaluated impact categories. The benefits of unbleached packaging paper are a consequence of the surplus energy that is generated from the alkali extraction process and from the reduced burdens associated with eliminating the demand for bleaching chemicals. The sensitivity analysis highlighted the benefit to the environmental performance if on-site power is used internally to offset electricity consumed from the grid. The database comparison illustrated a much lower impact on climate change and resources when the studied product system for bleached packaging paper was compared to the equivalent functional unit for plastic packaging.

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