Sustainability assessment of biomass utilization and energy recovery - A study in Svåheia, Norway

Abstract

This study examines the environmental impacts of various subprocesses in the syngas production—transportation, drying, pelletization, and gasification. It identifies gasification as the most environmentally detrimental due to its energy-intensive nature, contributing significantly to air and water emissions. This process is primarily responsible for 77.7% climate change, 65.3% eutrophication, 59.1% human toxicity, 55.09% particulate matter, and 68.13% photochemical oxidant impacts. Conversely, the drying process is a major contributor to 75.07% of acidification primarily from ammonia emissions. The pelletization process contributes to environmental impacts, accounting for 14.5% of ecotoxicity, 13% of eutrophication, and 15.08% of particulate matter formation. These effects are primarily due to the consumption of electricity and the use of carboxymethyl cellulose as a binding agent. The transportation processes contribute to 14.5% ecotoxicity and 15.08% particulate matter formation through vehicle wear and tear.

This study further discusses two ash management strategies integrated into the syngas production chain, highlighting the use of ash in the cement industry as a more sustainable and controlled method compared to its application in soil remediation. Cement approach notably reduces several environmental impacts. This method is primarily advantageous as it eliminates the need for Portland cement as a raw material. Additionally, it shows that high temperatures can effectively stabilize heavy metals within construction materials, thus preventing them from leaching into the environment.

Both ash management scenarios show improved sustainability over landfilling, with cement production emerging as the preferable option.

A sensitivity analysis underscores the environmental advantages of using renewable energy, which reduces most pollutants compared to fossil fuels, although it increases human toxicity about 20.6 kg 1,4-DCB-Eq due to the hazardous materials involved in the production and disposal of renewable technologies.

In conclusion, the thesis suggests that switching to less energy-intensive oxygen and steam suppliers in the gasification process and adopting sustainable ash management methods can significantly mitigate environmental impacts. These changes, coupled with the strategic use of renewable energy sources, could enhance the overall sustainability of the syngas production process.

This study examines the environmental impacts of various subprocesses in the syngas production—transportation, drying, pelletization, and gasification. It identifies gasification as the most environmentally detrimental due to its energy-intensive nature, contributing significantly to air and water emissions. This process is primarily responsible for 77.7% climate change, 65.3% eutrophication, 59.1% human toxicity, 55.09% particulate matter, and 68.13% photochemical oxidant impacts. Conversely, the drying process is a major contributor to 75.07% of acidification primarily from ammonia emissions. The pelletization process contributes to environmental impacts, accounting for 14.5% of ecotoxicity, 13% of eutrophication, and 15.08% of particulate matter formation. These effects are primarily due to the consumption of electricity and the use of carboxymethyl cellulose as a binding agent. The transportation processes contribute to 14.5% ecotoxicity and 15.08% particulate matter formation through vehicle wear and tear.

This study further discusses two ash management strategies integrated into the syngas production chain, highlighting the use of ash in the cement industry as a more sustainable and controlled method compared to its application in soil remediation. Cement approach notably reduces several environmental impacts. This method is primarily advantageous as it eliminates the need for Portland cement as a raw material. Additionally, it shows that high temperatures can effectively stabilize heavy metals within construction materials, thus preventing them from leaching into the environment.

Both ash management scenarios show improved sustainability over landfilling, with cement production emerging as the preferable option.

A sensitivity analysis underscores the environmental advantages of using renewable energy, which reduces most pollutants compared to fossil fuels, although it increases human toxicity about 20.6 kg 1,4-DCB-Eq due to the hazardous materials involved in the production and disposal of renewable technologies.

In conclusion, the thesis suggests that switching to less energy-intensive oxygen and steam suppliers in the gasification process and adopting sustainable ash management methods can significantly mitigate environmental impacts. These changes, coupled with the strategic use of renewable energy sources, could enhance the overall sustainability of the syngas production process.