Regional variations in life cycle greenhouse gas emissions of canola‐derived jet fuel produced in western Canada

Abstract

This study investigates the life cycle GHG emissions of jet fuel produced via the hydroprocessed esters and fatty acids (HEFA) pathway from canola grown in western Canada, with a focus on characterizing regional influences on emissions. We examine the effects of geographic variations in soil type, agricultural inputs, farming practices, and direct land use changes on life cycle GHG emissions. We utilize GREET 2016 but replace default feedstock production inputs with geographically representative data for canola production across eight western Canadian regions (representing 99% of Canada's canola production) and replace the default conversion process with data from a novel process model previously developed in ASPEN in our research group wherein oil extraction is integrated with the HEFA‐based fuel production process. Although canola production inputs and yields vary across the regions, resulting life cycle GHG emissions are similar if effects of land use and land management changes (LMC) are not included; 44–48 g CO2e/MJ for the eight regions (45%–50% reduction compared to petroleum jet fuel). Results are considerably more variable, 16–58 g CO2e/MJ, when including effects of land use and LMC directly related to conversion of lands from other uses to canola production (34%–82% reduction compared to petroleum jet fuel). We establish the main sources of emissions in the life cycle of canola jet fuel (N‐fertilizer and related emissions, fuel production), identify that substantially higher emissions may occur when using feedstock sourced from regions where conversion of forested land to cropland had occurred, and identify benefits of less intense tillage practices and increased use of summerfallow land. The methods and findings are relevant in jurisdictions internationally that are incorporating GHG emissions reductions from aviation fuels in a low carbon fuel market or legislating carbon intensity reduction requirements.

A framework to estimate national biofuel potential by siting production facilities: a case study for canola sustainable aviation fuel in Canada

“…The higher LC-GHG emissions in RU-34 is due to the legacy emissions associated with the conversion of forest land to cropland over the years. 57 The canola-derived SAF from RU-23 has an LC-GHG emission of 54 g CO 2 e per MJ, nearly as high as RU-34, but the total available canola in this upper Manitoba region is just 2%, and therefore unlikely to affect the national average LC-GHG emissions. RU-30, on the other hand, has the lowest LC-GHG emissions with just 16 g CO 2 e per MJ – almost 72% lower than LC-GHG emissions from RU-34, and has about 15% of available canola.…”

“…The LC-GHG at potential sites depends on local characteristics such as soil, previous use of the land before canola, regional fertilizer consumption, and local farming practices. Obnamia et al , 57 reported the LC-GHG emissions of canola-derived SAF for each Canadian reconciliation unit (RU). An RU is a regional zone in Canada for reporting data land and activity from multiple agencies; an RU is considerably larger than the BIMAT sites used for analysis in our study.…”

“…The RU with the largest canola availability is also the region with the largest LC-GHG emissions. RU-34 has nearly 20% of the available canola but has LC-GHG emissions of 58 g CO 2 e per MJ, suggesting that plants in the northern Alberta region 57 The optimal plant sites identified are likely to collect canola from multiple RUs depending on the location, leading to weighted average LC-GHG emissions from different RUs. Fig.…”

“…Optimal SAF plant locations and their profitability (IRR) for 25% feedstock accessibility criteria for a 0.6 $ per L incentive. Airport IATA codes: YEG-Edmonton, YYC-Calgary, YXE-Saskatoon, YQR-Regina, and YWG-Winnipeg GHG emissions in RU-34 is due to the legacy emissions associated with the conversion of forest land to cropland over the years 57. The canola-derived SAF from RU-23 has an LC-GHG emission of 54 g CO 2 e per MJ, nearly as high as RU-34, but the total available canola in this upper Manitoba region is just 2%, and therefore unlikely to affect the national average LC-GHG emissions.…”

Employing a Socio-Technical System Approach in Prospective Life Cycle Assessment: A Case of Large-Scale Swedish Sustainable Aviation Fuels

“…,Larson et al (2020),Obnamia et al (2020),Pamula et al (2021),and Prussi et al (2021), etc. compared life cycle GWP 100 of different SAF to that of conventional jet fuel.…”