The Use of Canola for Biofuel Production in the Context of Energy Security—A Systematic Literature Review

Abstract

This study examines the evolving role of canola biofuel in achieving energy security, analyzing its historical significance, current challenges, and prospects. Once a dominant feedstock for biodiesel production in Europe, canola biofuel is facing a decline in relevance due to the emergence of second- and third-generation biofuels, which offer greater economic and environmental advantages. The research highlights key factors influencing this shift, including high production costs, resource-intensive cultivation, and suboptimal life cycle environmental performance. Through correlation and causality analyses, the study finds no definitive relationship between oil prices and the frequency of scientific publications on canola biofuels, suggesting other drivers, such as policy and technological advancements, play a more significant role. Despite its diminishing prominence, canola biofuel retains value in energy diversification and rural agricultural support, due to geographic, policy, and investment constraints. The findings emphasize the need for prioritizing the development of more sustainable and efficient biofuel technologies to address global energy and environmental challenges.

1. Introduction

Rising oil prices at the turn of the 20th century and advances in agricultural production efficiency have significantly increased interest in biofuels as an alternative energy source. Biofuels are regarded not only as a means to increase energy independence but also as an opportunity for farmers to diversify their income. Their use is still controversial, due to their lower heating value compared to fossil fuels and their potential negative effects on the food market. Particularly during the 2007–2008 food price crisis, public debate focused on the competition between the food and fuel sectors for agricultural feedstocks. The European Union’s biofuel policy is constantly evolving—on the one hand, supporting the reduction of CO₂ emissions by promoting renewable energy sources, and on the other hand putting increasing emphasis on sustainable food production, which may limit the use of first-generation biofuels based on food raw materials.

Biofuels in the 21st century have gained the interest of different stakeholders, such as states, investors, and companies. They are especially attractive due to their potentially infinite exploitation capabilities, i.e., they are renewable energy sources. The economics of canola biofuel are influenced by the price of the material [1], production technology [2], and government subsidies and policies [3]. Biodiesel can be used both in transportation and logistics as fuel [4], as well as in the energy sector, e.g., energy power plants, etc. [5]. The broad implementation of this new energy source can be a chance to develop new branches of the energy industry and sustain the expected level of energy security. At the same time, the exploration of this technology brings potential challenges, as the properties of these fuels in some cases differ from traditional diesel fuels. In contrast, in others, they show certain similarities (Figure 1).

An analysis of 11 key fuel-quality parameters reveals that biodiesel generally conforms to ASTM D-6751/EN 14214 standards for viscosity, density, flash point, and cetane number. This indicates that diverse biodiesel production pathways, irrespective of the feedstock, typically yield a fuel that exhibits safe handling characteristics and reliable ignition properties. Median values from collected first-generation biodiesel data generally meet ASTM D-6751/EN 14214 specifications for viscosity, density, flash point, and cetane number, indicating safe handling and reliable ignition across diverse feedstocks. These ranges are presented in Figure 1, while calculations for the figure are presented in

Table A1. Chemical and physical properties of biofuels. Final calculations.

Property	Min	Q1	Median	Q3	Max
Kinematic Viscosity (mm2/s at 40 °C)	2.2	4.09	4.6	5.3	17.14
Density (kg/m3 at 15 °C)	87.4	867	877	890.02	922
Cetane Number	37.55	48.875	52.94	59.215	76.74
Higher Heating Value (MJ/kg)	18.33	26.42	38.6225	40.79	52.2
Flash Point (°C)	70	146.4	166.6	175.5	241
Cloud Point (°C)	−25	2.25	9.835	13	26
Pour Point (°C)	−28	−2.35	4	8.06	18
Sulfur Content (ppm)	0	10	15	50	210
Free Glycerine (%)	0.005	0.015	0.02	0.02	0.1
Acid Number (mg KOH/g)	0.072	0.19	0.37	0.5	1.2
Oxidation Stability (hours)	0.18	1.5825	2.945	8.0025	20.7

Source: Own calculations, based on the literature review [6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27].

in Appendix A. However, median cold-flow properties (cloud/pour points often >+10 °C) and oxidation stability (≈3 h, vs. ≥6 h biodiesel standard) show limitations linked to feedstock chemistry. Saturated fats improve cetane and stability but worsen cold flow, while polyunsaturated oils show the opposite trend. Processing issues can elevate sulfur, acid number, and free glycerine, particularly in waste oil-derived biodiesel. These can be mitigated with refining, allowing biodiesel to meet most of its specifications with cold-flow improvers or blending for harsh climates.

For engine-related parameters (viscosity, density, cetane number), median first-generation biodiesel values fall within biodiesel standards and overlap with diesel ranges. The median heating value of first-generation biodiesel (38.6 MJ kg⁻¹) is lower than both biodiesel (37–42 MJ kg⁻¹) and diesel (42–46 MJ kg⁻¹) standards, explaining the typical 8–12% higher consumption. The median flash point (167 °C) for first-generation biodiesel exceeds both biodiesel (≥100 °C) and diesel (60–80 °C) requirements. Conversely, median cold-flow properties (interquartile ≈ 10/−2 °C) for first-generation biodiesel are poorer than winter diesel targets (≤−15/−15 °C), necessitating additives or blending. Median sulfur (15 ppm, matching ultra-low sulfur diesel ceiling), free glycerine (0.02%), and acid number (0.37 mg KOH g⁻¹) in first-generation biodiesel are below biodiesel limits, with no direct diesel equivalents. Oxidation stability (median 2.9 h) of first-generation biodiesel remains a key weakness relative to both biodiesel (≥6 h) and diesel (>30 h) expectations, highlighting the need for antioxidants. Moreover, some biodiesel—including canola biodiesel—varieties can be more corrosive than traditional fuels, which can negatively affect the lifespan of machinery.

Biofuel from canola, in the form of canola oil methyl esters (RME), is commonly blended with diesel, as well as used in its pure form (B100) [28,29]. There are several methods of biofuel production (Table 1).

Table 1. Biofuel production methods.

Method	Process	Source
Transesterification	Reaction of vegetable oil with alcohol in the presence of a catalyst	Gaide et al., 2024 [30]
Hydrothermal hydrogenation	Extraction of the biofuel from the biomass with high temperature	Demirbas, 2007 [5]

Source: own work, based on the literature review.

Table 1. Biofuel production methods.

Method	Process	Source
Transesterification	Reaction of vegetable oil with alcohol in the presence of a catalyst	Gaide et al., 2024 [30]
Hydrothermal hydrogenation	Extraction of the biofuel from the biomass with high temperature	Demirbas, 2007 [5]

Source: own work, based on the literature review.

In the second decade of the 21st century, canola constituted ca. 80% of the biodiesel source in Europe [28,31], while in the third decade, it was already only ca. 40% [32]. This raises the question of the role of canola biodiesel as a pillar in the energy security infrastructure. At the same time, although canola is losing its significance in the (renewable) energy mix, it is still important in maintaining energy security—at least as long as other energy sources do not replace it. Such a replacement only occurs as the alternatives can become attractive, due to, e.g., economic viability, mechanical efficiency, or environmental reasons. Thus, both the positive and negative sides of canola biofuel production must be considered.

The body of research on canola-based biofuel production in the context of energy security shows a lack of comprehensive analysis in this field, and is related to specific regulations, canola cultivation technology, efficiency of biofuel production, or their use in transport. To fill the research gap, a literature review was conducted to systematize the research results in two databases: Web of Science and Scopus (Appendix A,

Table A2. Compilation of data on oil prices and number of publications on the topic researched.

Year	Scopus	Web of Science	Merged and Deduplicated	After Manual Exclusion	U.S. No 2 Diesel Ultra Low Sulfur (0–15 ppm) Retail Prices (Dollars per Gallon)	U.S. All Grades, All Formulations, Retail Gasoline Prices (Dollars per Gallon)
2025	1	0	1	1	N/A	N/A
2024	7	9	11	10	3.814	3.424
2023	0	4	4	4	2.473	3.635
2022	10	9	15	11	2.993	4.059
2021	12	9	13	11	3.84	3.1
2020	16	15	21	20	3.968	2.258
2019	6	9	10	10	3.922	2.691
2018	9	9	14	11	3.825	2.813
2017	4	10	10	8	2.707	2.528
2016	11	9	14	12	2.304	2.25
2015	16	12	20	18	2.65	2.52
2014	21	14	25	22	3.178	3.437
2013	18	18	27	23	3.056	3.575
2012	10	9	15	13	2.551	3.68
2011	19	15	20	20	3.287	3.576
2010	10	11	16	16	4.989	2.835
2009	9	10	13	13	4.214	2.406
2008	15	8	20	20	3.76	3.299
2007	12	7	15	15	N/A	2.843
2006	7	3	7	6	N/A	2.618
2005	5	1	5	5	N/A	2.314
2004	0	0	0	0	N/A	1.895
2003	1	1	2	1	N/A	1.603
2002	1	1	2	2	N/A	1.386
2001	0	0	0	0	N/A	1.46
2000	1	0	1	1	N/A	1.523
1999	1	1	1	1	N/A	1.176
1998	0	0	0	0	N/A	1.072
1997	0	0	0	0	N/A	1.244
1996	0	0	0	0	N/A	1.245
1995	1	1	1	1	N/A	1.158
1994	0	0	0	0	N/A	1.078
1993	1	0	1	1	N/A	N/A

Source: own compilation, based on the data from the U.S. Energy Information Administration and from the World Bank.

).

The goal of the research was to identify the role of canola biofuel in achieving energy security based on a systematic literature review, as well as trends, challenges, and perspectives for its future. The study formulates two research hypotheses:

Hypothesis 1 (H1).

An increase in fuel prices leads to an increase in interest in biofuel production, which translates into more research in this field.

Hypothesis 2 (H2).

In countries with the largest canola production, research on its use in biofuel production is more often represented in the literature.

The study consists of several parts. The introduction presents the rationale for undertaking research. Then, the literature review method and the statistical methods used are presented. Next, the relationship between energy prices and research on the use of canola for biofuel production is assessed. The results of broad and narrow bibliometric analyses of this issue in the context of energy security are presented. An essential element of the study was the identification of economic aspects of the use of canola in the production of biofuels, considering its strengths and weaknesses, opportunities, and threats. Then, the results of the analysis were discussed. The article ends with a discussion, conclusions, and recommendations.

2. Method

In the systematic literature review, the PRISMA method has been applied [33]. The source of the information for the review was a query conducted on 21 January 2025. As part of the research, the available literature was obtained regarding the use of canola to produce biofuels. The analysis used two main scientific databases: Scopus and Web of Science (WoS). The Scopus database identified 224 publications, and the WoS database identified 195 publications. Both databases were exported in BibTeX format and subsequently merged using the R software (version 4.4.2) with the use of Bibliometrix package [34]. During data loading, two corrupted entries from the Scopus database were discarded, resulting in an initial dataset of 222 articles. The databases were combined, and duplicate entries were removed. In total, 113 duplicates were eliminated (over 25%) by the software. Such a strong overlap is characteristic of broad, well-documented research niches. The merged dataset initially contained a total of 304 articles. The manual review identified an additional sixteen duplicates not detected by the software.

Later, the articles in the database were assigned to different categories (see

Table 2. The main themes in the broad body of research on canola biofuel production.

Category	Total Papers	Included Papers	Inclusion Rate (%)	Rejection Rate (%)
Agricultural Practices and Biomass Utilization	174	160	91.95	8.05
Bioenergy and Biogas Production	72	65	90.28	9.72
Other/Unclassified	26	21	80.77	19.23
Environmental Impact and Sustainability	15	15	100.00	0.00
Climate Change and Renewable Energy Policies	10	10	100.00	0.00
Case Studies and Regional Studies	6	4	66.67	33.33
Biotechnological Innovation in Bioenergy	1	1	100.00	0.00
SUM	304	276	90.79	70.33

Source: own study.

). Twelve articles, which did not meet the criteria for addressing issues related to canola-derived biofuels, were excluded. The rejection rate in each category was calculated. As a result, the final dataset comprised 276 articles. The highest rate of rejections was in the category of case studies and regional studies, in which the reference to canola appeared casually. At the same time, the number of these studies was so low (only 6) that rejection of every article caused an increase in the rejection rate by over 16%. The second category with the highest rejection rate comprised articles that were in the category other/unclassified (almost 20%), and some rejected articles spoke about the topics of biofuel or transesterification too broadly to qualify them as ones concerning canola-based biofuels.

Research on biofuel development addresses four primary challenges: feedstock optimization for improving crop yields, waste-to-energy strategies for utilizing byproducts, policy integration to assess government incentives and regulations, and technological advancements in biofuel conversion methods. While these categories are interconnected, each focuses on distinct scientific, economic, or engineering aspects.

In the next stage, the study employed a comprehensive two-stage methodology. Initially, a Pearson correlation analysis was conducted to explore the relationship between the number of scientific publications on canola biofuels and fuel prices, aiming to understand how external economic factors—such as fuel price hikes—influence research interest. This analysis utilized data from Scopus and Web of Science, along with time series fuel price data, incorporating one- and two-year lags to account for delayed responses. The significance threshold of 0.05 was adopted in the analysis. To test whether changes in oil prices are indeed causing an increase in biodiesel research, a Granger causality test was applied. Subsequently, an in-depth bibliometric analysis was performed on a narrower set of publications identified by a refined search code focusing on energy security. This bibliometric stage involved keyword co-occurrence analysis, topic mapping, and the evolution of research trends, highlighting the significance of energy security in the biofuel literature, with special attention to canola biofuel. The technical description of the process is presented in

Table 3. Stages of the bibliometric research on the topic of canola biofuel production, as well as within energy security context.

Stage	Scopus Search Term	Web of Science Search Term
1	(TITLE-ABS-KEY (“biodiesel” OR “biofuel *”) AND TITLE-ABS-KEY (“rape” OR “rapeseed” OR “canola”) AND TITLE-ABS-KEY (“farm *” OR “holding *” OR “agroholding *”))	(TITLE-ABS-KEY (“biodiesel” OR “biofuel *”) AND TITLE-ABS-KEY (“rape” OR “rapeseed” OR “canola”) AND TITLE-ABS-KEY (“farm *” OR “holding *” OR “agroholding *”))
2	(TITLE-ABS-KEY (“biodiesel” OR “biofuel *”) AND TITLE-ABS-KEY (“rape” OR “rapeseed” OR “canola”) AND TITLE-ABS-KEY (“security”))	“biodiesel” OR “biofuel *” (Topic) and “rape” OR “rapeseed” OR “canola” (Topic) and “security” (Topic)

Source: own study (see Appendix B).

.

Furthermore, the collected literature was examined to evaluate the economic relevance of this research area, enabling a deeper understanding of broad economic phenomena affecting science and providing detailed insights to identify research gaps and potential directions for future studies. In the final literature review, the SWOT method was applied to analyze the information on the economic performance of canola biofuel, as well as canola biofuel was compared to other biofuel feedstocks, from an economic perspective.

3. The Relation Between Energy Prices and Canola Biofuel Research

The earliest studies on this topic appeared in Scopus in 1993 and in WoS in 1995. A notable increase in interest in this field has been observed since 2006. Figure 2 illustrates a growth in publications at times of the energy price spikes (e.g., in 2008), which may have subsequently contributed to a decline in interest due to the excessive costs of this energy source at the time.

Pearson correlation analysis revealed a moderately strong positive relationship (0.75) between annual changes in different fuel prices and the number of publications on biodiesel. This finding indicates that periods of rising oil prices correspond to an increase in scientific activity within this field, suggesting a potential linkage between the prices of conventional fuels and interest in alternative energy sources (

Table 4. Pearson correlations between different fuel prices and rates of studied publications.

Data Source	Scopus	WoS	Merged	After Manual Exclusion
Diesel	0.05	0.11	0.06	0.17
Retail gas	0.71	0.75	0.77	0.75
Average nominal crude	0.76	0.76	0.81	0.80
Average real crude	0.76	0.74	0.80	0.80

Source: own study.

). This means that the first hypothesis (H1) has been verified positively.

To evaluate whether research reacts with a time lag to changes in oil prices, a time lag analysis was conducted, i.e., delays of one and two years. The addition of lags has shown a very weak correlation between fuel prices and academic activity regarding canola biofuel research (

Table 5. Pearson correlations between the energy price hikes and the number of publications on the topic, including 1- and 2-year lags.

Data Source	Scopus			WoS			Merged and Deduplicated
Corellations	Baseline	Lag 1	Lag 2	Baseline	Lag 1	Lag 2	Baseline	Lag 1	Lag 2
Crude_Nominal	0.2861			0.1408			0.3230
Crude_Nominal_Lag 1		0.0705	0.0705		0.2186	0.2186		0.0823	0.0823
Crude_Nominal_Lag 2		0.1083	0.1083		−0.0857	−0.0857		−0.2110	−0.2110
Crude_Real	0.3283			0.1720			0.3781
Diesel_Price	0.0534			0.1097			0.0570
Diesel_Price_Lag 1		−0.4459	−0.4459		−0.2574	−0.2574		−0.3377	−0.3377
Diesel_Price_Lag 2		−0.4549	−0.4549		−0.5984	−0.5984		−0.4067	−0.4067
Gasoline_Price	0.0783			−0.0556			0.0937

Source: own study.

). The results indicated a stronger correlation occurring with a one-year lag, suggesting that research interest in biodiesel may increase about a year after the change in oil prices. In contrast, the strength of the correlation was weaker with a two-year lag, indicating that the effect of oil prices on research activity quickly diminishes, peaking in the year of price hikes.

This pattern challenges the assumption that canola biofuel research follows a gradual response to energy market trends. Instead, it suggests that researchers, institutions, and funding agencies may be reacting hastily to unexpected economic shifts, possibly through fast-tracked research initiatives. Another possibility is that price hikes trigger increased policy discussions, or public and media attention, which could accelerate short-term research engagement even before new funding is allocated. This raises questions about whether biofuel research is primarily driven by sustained long-term energy strategies or by reactive surges in interest during energy crises.

To evaluate whether changes in oil prices are indeed causing an increase in biodiesel research, a Granger causality test was applied (

Table 6. Granger causality test for the applied lag correlations between the energy price hikes and the number of publications on the topic.

Lag	p-Value (Scopus)	p-Value (Web of Science)	p-Value (Merged)
1	0.8377	0.5898	0.8200
2	0.8142	0.3892	0.3774

Source: own study.

). The results of this test did not show a statistically significant relationship—the p-values were significantly higher than the 0.05 significance threshold for both the one-year and two-year lags. This means that although there is a correlation between oil prices and the number of scientific publications, it cannot be conclusively stated that the increase in oil prices is a direct cause of increased research activity. It is possible that other factors, such as energy policy, regulations, the availability of research funds, or the general development of biofuel-related technologies, are also influencing research dynamics.

The analysis showed an existing relationship between oil prices and the number of biodiesel publications, with price effects likely to show up with some lag, especially after one year. The p-values remain above 0.05, meaning that past changes in oil prices do not statistically predict future biodiesel research results. This indicates that while there is a correlation, it is not a direct cause-and-effect relationship. The lack of statistical causality suggests that other factors are influencing the number of publications. In the future, it would be worth conducting more sophisticated analyses that consider other variables, such as government regulations or global trends in renewable energy research.

4. An Outlook on the Broad Bibliometric Outcome

The broad search outcomes were also investigated (Figure 3) for initial insights into the body of research. The most frequent terms in the analyzed literature were, obviously, Brassica napus (89 occurrences), biofuel (85 occurrences), and biofuels (75 occurrences). Other notable terms include crops (72 occurrences) and biodiesel (57 occurrences), emphasizing the agricultural and production contexts. Keyword trends reveal shifts in focus, with esterification peaking around 2008, and renewable energy resources gaining prominence between 2007 and 2010. The analysis highlights Brassica napus as a central focus in biofuel research, reflecting its consistent prominence throughout the dataset, with a significant increase in mentions in 2011 (+13 occurrences). Biofuel and biofuels show a steady rise, mirroring global interest in renewable energy, with notable spikes in 2011 (+8 occurrences) and 2013 (+7 occurrences), respectively. Crops maintain relevance by linking biofuel production to agriculture, peaking in 2016 (+10 occurrences), while biodiesel demonstrates periodic peaks aligned with advancements in the field, including a significant jump in 2011 (+7 occurrences). A geographic emphasis on Europe peaked around 2009. The USA leads in scientific output (75 publications), followed by Italy (41), the UK (35), Germany (34), and Brazil (27).

5. Second Bibliometric Attempt—Major Themes and Methods Applied

Second, a narrower literature search found 83 articles in the Scopus database and 82 articles in the WoS database. Subsequently, 53 duplicated articles were removed, and the full merged database comprised 113 articles. These articles were screened for possible duplicates, which were not removed by the software. Three additional duplicates were identified and removed manually. Thus, the database shrank to 110 articles. Lastly, the titles of articles were screened for thematic consistency with the research. If in question, abstracts were screened additionally.

The data analyzed show that no scientists focus on canola biofuel production precisely from an energy security perspective, and almost every author has written no more than one or two articles on the subject. This could be due to other energy sources possibly being treated as central for energy production. Interestingly, the universities that have issued the highest number of papers on the given subject are not the global leaders in canola production research (

Table 7. Universities leading publications on canola biofuel production in the context of energy security.

University	Michigan Technological University	Selcuk University	University Malaya	Vytautas Magnus University
Country	USA	Türkiye	Malesia	Lithuania
Number of publications	5	4	4	4

Source: own study.

). The only country that is among the top 10 canola producers in the world is the USA, where Michigan Technological University originates, and still, the USA is only in eighth place globally [35]. Thus, surprisingly, there are no strong research communities on the topic in the leading canola-producing countries. Thus, the second hypothesis (H2) was verified negatively.

Global leaders in canola production, such as Canada, China, India, and many EU countries, are not strongly represented in this body of research. However, it is important to note that the database does not give justice to Italian authors (e.g., Bentivoglio, Cozzi, Finco, Romano), who are among the top contributors. Yet, the data do not display Italy as one of the top contributors. The reason for this may be different written entries from the same universities. Seemingly, the more proper impact of the top canola-producing countries can be seen in the table on the corresponding author’s countries, where the top ones are Italy, Malaysia, and UK (4 publications), followed by the USA, Australia, Canada, India, Netherlands, and Poland, which are large canola producers. Similarly, among the top countries that contribute to the topic is, surprisingly, Malaysia, followed by the strong canola-producing countries (

Table 8. Research contribution by different countries in the research of canola biofuel in the context of energy security.

Country	Malaysia	UK	Italy	USA	Poland	India	Lithuania	Turkey	Australia	Brazil
Number of studies	10	10	6	6	5	4	4	4	3	3

Source: own study.

).

A correspondence analysis map was used to visualize the relationships between thematic issues, revealing clusters and trends in biofuel research (Figure 4). The X-axis differentiated technical aspects such as fuel production and performance (“diesel fuel”, “rapeseed oil”) from broader themes of sustainability and policy (“life cycle analysis”, “climate change”). The Y-axis separated highly specific topics (“biodiesel production”, “feedstocks”) from more integrated themes (“bioenergy”, “energy security”). Key clusters emerged: technical production and agricultural inputs (top-left), fuel performance (bottom-left), environmental sustainability (top-right), and policy frameworks (bottom-right). Energy security, centrally positioned, bridges technical and policy-focused research, highlighting biofuels as a strategic alternative to fossil fuels. Growing emphasis on life cycle analysis and environmental impact underscores the increasing importance of sustainability in biofuel studies.

Next, the articles were analyzed concerning the key themes and concepts. The Biblioshiny software has assigned seven themed clusters, assigning to them different rates of the so-called betweenness centrality, i.e., the importance of certain themes in the context of the research network studied. The higher the value of the betweenness, the more prominent it is within the whole network. The value of closeness signals the ability of a node to quickly connect with other nodes, while page rank signals the importance of the node among other nodes. In all the categories, there were constantly three terms—“energy security”, “biodiesel”, and “biofuels”. The strongest in the network was the phrase “energy security”, indicating that it is central to all the analyzed themes. Strong betweenness is also represented by the “biodiesel” and “biofuels” nodes, while “biodiesel production” represents moderate betweenness strength, signaling that the technological and production processes are not the most relevant for the studied body of research. The top three of these nodes are shown in

Table 9. Co-occurrence network, top three terms in all categories in the canola biofuel production research.

Node	Cluster	Betweenness	Closeness	Page Rank
Energy security	1	291.69	0.0178	0.092
Biodiesel	1	161.22	0.0169	0.070
Biofuels	1	94.55	0.0153	0.054

Source: own study.

.

Terms with a high rate of betweenness (e.g., “rapeseed oil” and “fossil fuels”) are fundamental for bridging technical and policy domains, being pivotal in connecting disparate areas of biofuel research. Closeness highlights well-connected terms that are central to the immediate thematic structure (e.g., “climate change”), which may indicate topics closely related to biofuel sustainability and environmental considerations. Page rank captures the broader influence of terms like “life cycle” and “greenhouse gases”, indicating their importance in shaping discussions, even if they are not direct connectors.

Energy security, biodiesel, and biofuels are consistently dominant across metrics, highlighting their critical role in discussions. The variations (e.g., the inclusion of “rapeseed oil” in betweenness and “life cycle” in page rank) reveal nuanced roles of these terms, either as bridges, central concepts, or influential themes. These differences provide insights into how themes like sustainability (“greenhouse gases”) and technical details (“life cycle”) integrate into broader discussions on canola biofuel.

The lower presence of terms strictly connected to canola itself might mean that it is not the question of whether there is an interest in energy security or biofuels overall, but whether canola itself is relevant to this topic. Canola might also occur as a background theme, being analyzed next to other biofuel sources. Similarly, in the context of the energy security, canola-based biodiesel occurs next to other biofuel sources (e.g., soybean oil, palm oil), indicating that it is a part of the context in the search for the most efficient biofuel feedstocks, with the importance of the environmental themes, especially in the orange cluster (see Figure 5).

Next, the thematic evolution of the topic was analyzed (Figure 6). The horizontal (relevance degree or centrality) axis represents the relevance of themes in the network. Themes further to the right are more integral to the network, influencing multiple topics and bridging concepts. The vertical (development degree or density) represents the maturity of themes. Higher values indicate well-developed ones, while lower values suggest less mature ones.

In the top-right quadrant (motor themes), the most relevant of the previous analysis were present (see Table 2), i.e., energy security, biodiesel, and biofuels, and are followed by more environmentally focused themes, such as life cycle, environmental impact, and sustainable development. The bottom-right quadrant (basic themes) presents relevant yet less developed themes. Here can be found such terms as bioenergy, energy policy, and ethanol, indicating evolving discussions on policy and alternative energy sources. These are followed by such terms as canola, performance, and diesel fuel, placing focus on the production and performance of biofuels. The top-left quadrant (niche themes) represents well-developed and highly specialized, but not highly relevant (i.e., not highly connected to the rest of the network) themes. These are such themes as diesel engines, gas emissions, and alternative fuels, which may focus on technical discussions on specific biofuel applications. Finally, the bottom-left quadrant (emerging and declining themes) represents less developed themes. Here, keywords such as methyl ester, biomass fermentation, and esterification can be found, which reflect technical or chemical aspects of biofuel that may be in early research phases or declining in focus. From a glance at the literature, it can be stated that these themes are declining, rather than emerging.

At the same time, it can be observed that environmental themes, although still lagging the economic ones, are the most relevant ones in the last years, and are strongly gaining traction (Figure 7, see words such as gas emissions or climate change).

The analyzed articles present biofuels as a crucial component of the energy transition, albeit one accompanied by significant challenges. Researchers employ diverse methods to comprehensively investigate this topic, with life cycle analysis (LCA) emerging as the dominant approach (Table 10). LCA evaluates the sustainability of biofuels by assessing their environmental, economic, and societal impacts across their entire life cycle, from raw material extraction to disposal [30,31,36,37,38,39]. In addition to LCA, other methodologies are employed:

• Economic analysis: Examines costs and benefits, impacts on food prices, market competitiveness, and energy security [1,3,28,38,40].
• Modeling: Utilizes mathematical models to simulate production processes, analyze scenarios, and forecast future developments [28,31,38,41].
• Comparative analysis: Compares various biofuel types, production technologies, and feedstocks to identify the most sustainable solutions [3,28,42,43].
• Laboratory research: Investigates biofuel properties and optimizes production through experimental studies [44].

The strong prevalence of LCA highlights its critical role in providing a holistic assessment of biofuel sustainability, making it an indispensable tool in guiding biofuel research and development. From the “focused lens” of our research (i.e., distilling only the papers that consider the question of energy security), LCA is the most commonly used methodology, reflecting the importance of environmental impact assessments in biofuel research, from cultivation to combustion [38,39,43]. This body of research has shown certain advantages of canola biofuel over ultra-low sulfur diesel (ULSD) regarding CO₂ emissions (26–32% reduction), but was characterized by higher nitrogen fertilizer-related emissions [38]. Similarly, research has evaluated biohydrogen from glycerol (lower emissions than natural gas-based hydrogen) (SMR-H₂) [43], while the waste oil biodiesel also had the advantage of reduced land use for its production [45]. Moreover, N₂O from nitrogen fertilizer application is another contributor to the GHG emissions [41], and although the reduction of nitrogen fertilizer in canola production could diminish N₂O emissions, it could reduce the economic viability of the canola biofuel altogether. NO_x emissions increased with higher biodiesel blends, rising by 10% for B10 and up to 37% for B100 [46]. CO₂ emissions decreased with biodiesel usage, with B100 achieving a 26% reduction and B20 achieving a 17% reduction [46]. The optimal biodiesel blend for emissions control and efficiency is B20, balancing fuel economy and emissions benefits. While the environmental benefits of biofuels are well-documented—especially their GHG emissions reductions and potential for energy security—their economic efficiency remains a concern. The numerical analysis of biofuel yield, energy consumption, and emissions suggests that some biofuel feedstocks and production pathways are more cost-effective than others.

Table 10. Methods used in energy security-concerned research analyzing canola.

Method	No. of Studies	Key Applications	Example Studies
LCA	8	Environmental impact, GHG emissions, energy balance	Stephenson et al., 2008 [38]; Stow et al., 2012 [39]; Susmozas et al., 2015 [43]; Ukaew et al., 2014 [41]
Experimental Testing	7	Engine performance, fuel properties, emissions analysis	Tesfa et al., 2014 [46]; Ali and Abuhabaya, 2012 [42]; Sales, 2011 [47]
Statistical and Econometric Analysis	4	Policy impact, market trends, economic efficiency	Chmielewski, 2022 [1]; Susmozas et al., 2015 [43]; Stow et al., 2012 [39]
Process Simulation (Aspen Plus, SimaPro, MATLAB)	3	Process modeling for hydrogen production, HRJ fuel synthesis, biofuel conversion	Susmozas et al., 2015 [43]; Ukaew et al., 2014 [41]; Taufiqurrahmi and Bhatia, 2011 [48]
Comparative Fuel Performance Studies	5	Comparing biodiesel vs. fossil fuels, hydrotreated fuels, and hydrogen energy	Tesfa et al., 2014 [46]; Ukaew et al., 2014 [41]; Sales, 2011 [47]
Catalytic and Chemical Process Optimization	3	Improving transesterification, catalytic cracking, hydroprocessing efficiency	Taufiqurrahmi and Bhatia, 2011 [48]; Suarez et al., 2009 [45]
Nitrogen Cycle and Fertilizer Impact Studies	2	Impact of canola fertilizer on N2O emissions and LCA accuracy	Ukaew et al., 2014 [41]; Susmozas et al., 2015 [43]

Source: own work, based on the literature review.

Table 10. Methods used in energy security-concerned research analyzing canola.

Method	No. of Studies	Key Applications	Example Studies
LCA	8	Environmental impact, GHG emissions, energy balance	Stephenson et al., 2008 [38]; Stow et al., 2012 [39]; Susmozas et al., 2015 [43]; Ukaew et al., 2014 [41]
Experimental Testing	7	Engine performance, fuel properties, emissions analysis	Tesfa et al., 2014 [46]; Ali and Abuhabaya, 2012 [42]; Sales, 2011 [47]
Statistical and Econometric Analysis	4	Policy impact, market trends, economic efficiency	Chmielewski, 2022 [1]; Susmozas et al., 2015 [43]; Stow et al., 2012 [39]
Process Simulation (Aspen Plus, SimaPro, MATLAB)	3	Process modeling for hydrogen production, HRJ fuel synthesis, biofuel conversion	Susmozas et al., 2015 [43]; Ukaew et al., 2014 [41]; Taufiqurrahmi and Bhatia, 2011 [48]
Comparative Fuel Performance Studies	5	Comparing biodiesel vs. fossil fuels, hydrotreated fuels, and hydrogen energy	Tesfa et al., 2014 [46]; Ukaew et al., 2014 [41]; Sales, 2011 [47]
Catalytic and Chemical Process Optimization	3	Improving transesterification, catalytic cracking, hydroprocessing efficiency	Taufiqurrahmi and Bhatia, 2011 [48]; Suarez et al., 2009 [45]
Nitrogen Cycle and Fertilizer Impact Studies	2	Impact of canola fertilizer on N2O emissions and LCA accuracy	Ukaew et al., 2014 [41]; Susmozas et al., 2015 [43]

Source: own work, based on the literature review.

6. SWOT Analysis of Canola-Based Biofuel Production—Energy Security Context

Canola biofuel is the so-called first-generation biofuel. In the future, these biofuels might be replaced by newer biofuel sources. Thus, the future of the canola-based biofuel is uncertain. On one hand, it can play a key role in the EU becoming independent of Russian fuel in the context of the war in Ukraine [1]. On the other hand, the future EU energy strategy might promote other energy sources.

From the point of view of energy security, an increase in biofuel production can allow fuel-importing countries to decrease their dependence on fuel imports [49]. Although biofuels themselves have lower GHG emission levels than traditional diesel fuels, their production processes can have negative environmental consequences, such as changes in land use, e.g., deforestation, and lead to increased water consumption [50], biodiversity loss [51], or pollution [39]. Thus, it is important to balance the potential increase in energy security with its possible negative impact on the environment, but also on water security. Some sources also evaluate the question of food and energy security, as competition can occur for land use and resources. For instance, Baka and Roland-Holst [3] state that in such a situation, food security must have a priority, also in the context of biofuel production.

The SWOT analysis (Figure 8) highlights the strengths of canola biofuels in terms of renewability and agricultural support while addressing their environmental and economic challenges. The outlined opportunities and threats underscore the need for innovation and policy alignment to maximize their potential as a sustainable energy source.

The strengths of canola biofuel stem predominantly from the scale of this industry within the (renewable) energy mix and its environmentally friendly potential. Canola-based biofuels are renewable energy sources, reducing dependence on finite fossil fuel reserves [4,5]. Their use results in lower GHG emissions compared to traditional fossil fuels, aligning with climate change mitigation goals [4,29,31]. Biofuels contribute to energy diversification and reduce reliance on imported fuels, enhancing energy security [5,29,52]. Canola cultivation supports agricultural sectors by providing income for farmers and promoting rural development [52,53].

The weaknesses of the canola biofuel depend on its pressure on other resources, as well as relatively high costs of development and machinery adjustment. Production requires significant water, energy, and land resources, potentially leading to negative environmental consequences [29,31,39]. The use of canola for biofuels can increase food prices due to competition for agricultural resources [40,54]. Canola biofuel production is more expensive compared to conventional fuels, limiting its economic competitiveness [53]. Pure canola biofuels (B100) may require engine modifications due to differences in physical and chemical properties [54,55].

The opportunities mainly point toward possible technological developments, which could at least keep a still high market share of canola biofuel in the overall energy mix, especially in developed countries. Advancements in production processes could lower costs and reduce environmental impact, making canola biofuels more competitive [31,37]. The development of new canola strains with higher oil content and improved quality could enhance production efficiency [52]. Increased use of canola byproducts for biofuel production offers a way to improve sustainability and diversify feedstocks [31,48]. Countries with high biomass production could increase canola’s role as a primary biofuel source [56].

The threats to this sector oscillate around themes of losing relevance in the energy mix due to comparatively low efficiency and excessive costs, and also environmental reasons. Non-food biomass sources or other crops like corn may replace canola in biofuel production due to lower costs and higher efficiency [1]. Changes in government policies, such as the EU’s focus on advanced biofuels, could diminish the role of first-generation biofuels like canola [1]. Fluctuating oil prices and subsidies for alternative energy sources may undermine the competitiveness of canola-based biofuels [1,49]. Continued concerns about the environmental footprint of canola cultivation (e.g., water use, deforestation) may limit its acceptance [31,39].

7. A Comparison of Canola with Other Biofuel Sources

The articles focusing on energy security offered a range span of analysis of different biofuel feedstocks, as compared to canola as the biofuel material. They were analyzed accordingly, and the advantages and disadvantages of these different energy sources were evaluated to assess the place of the canola biofuel in the energy mix. The summary of the particular features is illustrated in

Table 11. Comparison of canola with other biofuel sources.

Evaluation Criterion	Canola Biodiesel Performance	Better Alternative
Biofuel Yield (L/ha)	Moderate (1190 L/ha)	Palm oil (5950 L/ha), Microalgae (136,900 L/ha)
GHG Emissions	Lower than fossil fuels (2.415 g CO2-eq/MJ)	Biohydrogen (3.79 g CO2-eq/MJ)
N2O Emissions	Moderate (0.73 kg N2O/Mg)	Waste-based biofuels have lower emissions
Calorific Value	Lower than diesel (37.5 MJ/kg)	HRJ fuel (43.0 MJ/kg), Palm oil biodiesel (39.5 MJ/kg)
NOx Emissions	Higher than diesel (+10%)	Hydrotreated biofuels have lower NOx
Fuel Production Cost	Mid-range (USD 0.75–0.95/L)	Waste oil biodiesel (USD 0.40–0.60/L)

Source: own work, based on the literature review.

.

Several studies explored canola, sunflower, and maize as primary biofuel feedstocks [39,46]. Canola remains the dominant source for biodiesel and HRJ fuel production in the EU and USA due to its high oil content and well-established agricultural infrastructure. However, studies indicate that canola-based biodiesel faces sustainability challenges, including land-use competition, nitrogen fertilizer emissions, and energy-intensive processing [41]. The subsequent part of the analysis consisted of additional literature, concerned with the costs of biofuel feedstocks.

• Energy crops: sunflower, soybean, and palm oil

Sunflower oil biodiesel has also been evaluated for its emissions and efficiency [42], showing lower CO and CO₂ emissions than diesel but higher NO_x emissions. Sunflower biodiesel (37.5 MJ/kg) and canola biodiesel (lower than diesel at 42.5 MJ/kg) result in higher fuel consumption per unit of energy delivered [42], thus occurring as one of the least efficient biofuel sources, next to canola. This raises fuel costs for end-users unless offset by tax incentives. Soybean has the lowest yield (446 L/ha), making it less competitive for biodiesel production [45]. Palm oil (5950 L/ha) provides significantly higher yields than canola (1190 L/ha), making it a better large-scale option. For large-scale biodiesel production, palm oil is the most efficient land-based crop. Palm oil (5950 L/ha) offers the best land efficiency among traditional oil crops, but deforestation concerns and land acquisition costs have led to EU restrictions on palm-based biodiesel. Palm oil biodiesel faces regulatory challenges despite its low cost. Canola biodiesel is a solid but not optimal choice, due to higher land use than palm oil, lower energy density than hydrotreated fuels, or NO_x emissions. It is still better than fossil diesel in terms of GHG emissions.

2.

Waste oil

To improve biofuel sustainability, some research explored novel alternatives, such as waste cooking oils, animal fats, and non-edible oils (e.g., Jatropha, Macaúba palm) [45,48]. These materials decrease the food security-threatening food-versus-fuel conflicts and land-use impacts, offering low production costs while maintaining the demanded properties. Waste cooking oil and animal fats offer the lowest production costs since they utilize existing waste streams [45]. Biodiesel from waste oil requires less land, fewer resources, and has lower feedstock costs. Thus, although canola biodiesel shows the advantage regarding the CO₂ emissions (as also e.g., corn or waste oil exhibiting similar emission trends as canola), so do other biodiesel sources, with waste oil biodiesel saving land use for other production. Waste oil biodiesel is the best short-term economic choice, as it has the lowest production cost, land use that is derived only from the already used land for the vegetable oil production, granting sustainability. The downturn of this feedstock is its limited availability.

3.

Microalgae

Microalgae biofuels were recognized as having the highest oil yield per hectare (~136,900 L/ha), but their economic feasibility remains a challenge due to high processing costs and lipid extraction difficulties [45]. Microalgae have the highest yield (136,900 L/ha), but their production is still too costly for large-scale commercialization [45]. The cost of algae cultivation, harvesting, and oil extraction remains 5–10 times higher than conventional biodiesel.

4.

Hydrotreated fuels (HRJ) and biohydrogen

Hydrotreated fuels (HRJ) and biohydrogen seem to have an expansive outlook for the future, due to their lower GHG and NO_x emissions, and higher energy efficiency, although they are still costly. Overall, canola is a suitable biofuel crop for moderate-scale biodiesel production, but its land efficiency is outperformed by palm oil and microalgae. Canola biodiesel emits 2.415 g CO₂-eq/MJ, which is lower than conventional diesel (~87.5 g CO₂-eq/MJ) but higher than advanced biofuels like biohydrogen (3.79 g CO₂-eq/MJ). HRJ fuel (hydrotreated rapeseed jet fuel) emits 42.7 g CO₂-eq/MJ, meaning it achieves a ~50% reduction in emissions compared to fossil jet fuel. Glycerol, a biodiesel by-product, is used in biohydrogen production (GSR-H₂), reducing overall waste and improving economic efficiency [43]. Hydrotreated renewable jet (HRJ) fuel offers an energy efficiency advantage over biodiesel while achieving a 50% reduction in GHG emissions compared to Jet A fuel [41]. However, HRJ fuel requires expensive hydrogenation processes. Biohydrogen from bio-oil steam reforming (BSR-H₂) is more energy-efficient than glycerol-based hydrogen (GSR-H₂), suggesting that economic efficiency depends on selecting the right hydrogen production pathway [43]. Hydrotreated biofuels and second-generation biofuels (HRJ, BSR-H₂) reduce this efficiency gap but require high capital investment. Biohydrogen (BSR-H₂) and HRJ fuel are positioned for long-term growth, especially as aviation and maritime sectors seek decarbonization strategies. Hydrotreated fuels and biohydrogen are emerging as more efficient, promising long-term alternatives, though current costs remain a barrier. Biohydrogen is an emerging area, reflecting long-term decarbonization goals. Economic feasibility studies on biohydrogen and HRJ fuels are needed to assess their commercial viability. EU’s Renewable Energy Directive (RED II) restricts first-generation biofuels (food-based) to 7% of transport energy by 2030, pushing for advanced biofuels from waste and lignocellulosic biomass [1]. The U.S. Renewable Fuel Standard (RFS2) supports HRJ fuel due to its potential to meet aviation sector decarbonization goals [41]. Policymakers should focus on improving canola farming practices (e.g., reducing fertilizer use to lower N₂O emissions) while investing in hydrotreated and hydrogen-based biofuels for the future.

Canola biodiesel is a reliable, mid-range biofuel option, but not the most cost-effective or sustainable. It performs better than soybean, but worse than palm oil or microalgae [45], and remains viable in temperate regions (EU, Canada, northern USA), where palm oil cannot be cultivated [1]. There is potential for emissions reduction if agricultural practices improve (lower fertilizer use, better land management). Canola remains a strong contender in the EU and temperate regions where palm cannot be grown. Based on yield, processing costs, energy content, and emissions performance, waste oil biodiesel is the most cost-effective fuel currently available. Hydrotreated biofuels and biohydrogen have high potential but require major cost reductions to compete with fossil fuels. The decline of first-generation biofuels will push the industry toward waste-based and synthetic ones.

Table 12 summarizes the data from different academic papers on the price of biofuel production from different sources. Although the data are scattered among different time periods, it briefly provides an outlook on the material production costs. What can immediately be seen is that the production of canola is one of the most expensive production materials for biofuel. As reported by Miller et al. [57], one of the key factors in the canola biofuel production is the capital cost. This could suggest that canola is still such a widespread biofuel material due to the sunk costs of the producers, who already dispose of specific, canola-tailored technology, and a switch to another technology could be costly. Moreover, as reported by Fore et al. [58], canola has low refining requirements and processing costs, strengthening its attractiveness for producers. In contrast, Granjo et al. [59] claim that the processing of canola is energy-intensive, “missing the point” of producing an energy source which itself requires substantial energy resources. Thus, producers remaining with it may constitute a sunk-cost fallacy, i.e., due to the investments already made, they do not switch to novel, more efficient technologies. It can be well understood that entering a new biofuel production method would incur substantial costs, which may be out of reach for such producers, who may have acquired long-term loans to start the canola biofuel production, or have received grants or subsidies, which have to be finalized.

Table 12. Biofuel production costs by source.

Biofuel Source	Cost (USD/L)	Key Cost Factors	Source
Corn-based Ethanol (US)	USD 0.10–0.25	Yield, technology efficiency	Méjean and Hope, 2010 [60]
Sugarcane Ethanol (Brazil)	USD 0.05–0.08	Yield, efficient land use, low input costs	Méjean and Hope, 2010 [60]
Canola (Farm use)	USD 0.81	Production scale, energy input	COP AgriEnergy, 2011 [61]
Canola	USD 0.55–0.63	Production scale, coproducts, capital costs	Miller et al., 2012 [57]
Camelina	USD 0.28–1.04	Feedstock pricing, market demand for meal	Miller et al., 2012 [57]
Soybean	USD 0.40–0.60	Capital costs, feedstock pricing, co-product credits	Fore et al., 2011 [58]
Cellulosic Ethanol (Corn Stover)	USD 0.28–0.48/kg biomass	Biomass cost, technology development	Becerra-Pérez et al., 2022 [62]
Straight Vegetable Oil (Canola)	USD 0.64–0.83	Low refining requirements and processing cost	Fore et al., 2011 [58]
Soybean Biodiesel (Integrated Biorefinery)	USD 0.58	Process integration, coproducts (meal, lecithin), reduced waste	Granjo et al., 2017 [59]
Soybean Biodiesel (Standalone)	USD 0.79	Higher processing cost, standalone production, limited coproducts	Haas et al., 2006 [63]
Corn Ethanol (US)	USD 0.70	Energy-intensive process, government subsidies, land-use efficiency	Patzek, 2005 [64]
Canola (EU)	USD 0.69	Higher land use, higher feedstock costs	Haas et al., 2006 [63]
Soybean (US)	USD 0.53	Feedstock cost, refinery infrastructure, glycerol market effects	Haas et al., 2006 [63]
Canola (Canada)	USD 0.81	Feedstock cost, energy-intensive processing, smaller production scale	Granjo et al., 2017 [59]

Source: own study, based on the gathered literature.

Table 12. Biofuel production costs by source.

Biofuel Source	Cost (USD/L)	Key Cost Factors	Source
Corn-based Ethanol (US)	USD 0.10–0.25	Yield, technology efficiency	Méjean and Hope, 2010 [60]
Sugarcane Ethanol (Brazil)	USD 0.05–0.08	Yield, efficient land use, low input costs	Méjean and Hope, 2010 [60]
Canola (Farm use)	USD 0.81	Production scale, energy input	COP AgriEnergy, 2011 [61]
Canola	USD 0.55–0.63	Production scale, coproducts, capital costs	Miller et al., 2012 [57]
Camelina	USD 0.28–1.04	Feedstock pricing, market demand for meal	Miller et al., 2012 [57]
Soybean	USD 0.40–0.60	Capital costs, feedstock pricing, co-product credits	Fore et al., 2011 [58]
Cellulosic Ethanol (Corn Stover)	USD 0.28–0.48/kg biomass	Biomass cost, technology development	Becerra-Pérez et al., 2022 [62]
Straight Vegetable Oil (Canola)	USD 0.64–0.83	Low refining requirements and processing cost	Fore et al., 2011 [58]
Soybean Biodiesel (Integrated Biorefinery)	USD 0.58	Process integration, coproducts (meal, lecithin), reduced waste	Granjo et al., 2017 [59]
Soybean Biodiesel (Standalone)	USD 0.79	Higher processing cost, standalone production, limited coproducts	Haas et al., 2006 [63]
Corn Ethanol (US)	USD 0.70	Energy-intensive process, government subsidies, land-use efficiency	Patzek, 2005 [64]
Canola (EU)	USD 0.69	Higher land use, higher feedstock costs	Haas et al., 2006 [63]
Soybean (US)	USD 0.53	Feedstock cost, refinery infrastructure, glycerol market effects	Haas et al., 2006 [63]
Canola (Canada)	USD 0.81	Feedstock cost, energy-intensive processing, smaller production scale	Granjo et al., 2017 [59]

Source: own study, based on the gathered literature.

8. Technological Stagnation of the Canola Biofuels

The biofuels of the first generation (made of transestrified vegetable oils) were followed by biofuels of the second (made of lignocellulosic agricultural residues and non-edible energy crops, or waste) and third generation (mainly microalgae) as a consequence of technological stagnation [65,66]. The limitations of the first-generation biofuels were, e.g., low net energy yield, competition with food production and thus with food security goals (“food-versus-fuel” debate), and inflexible catalyst systems that hinder substantial improvements [67,68]. Moreover, research examining emissions and engine performance using canola biodiesel, such as the study by Çalık [69], has demonstrated that even when incorporating combustion enhancers, the fuel’s performance remains compromised compared to conventional diesel, largely due to the fuel’s chemical structure and combustion properties.

Canola-based biodiesel production faced technological stagnation due to inflexible catalyst systems, which limited reaction speed and economic viability, causing established transesterification methods to plateau with diminishing returns. In contrast, second-generation biofuels addressed these inefficiencies [67], e.g., through new conversion technologies, such as enzymatic and advanced chemical catalysis [70]. The broader shift towards these options was further propelled by the desire to utilize waste-derived biomass and residues, thereby avoiding competition with food resources and providing a flexible feedstock source. The advent of third-generation biofuels marked a technological shift, particularly with the emergence of algal biofuels, which offer high yield potential on non-arable land, as well as mitigate some environmental drawbacks associated with previous generations [71,72]. The emerging interest in biohydrogen as a complementary or alternative pathway illustrates a broader trend towards diversifying renewable energy portfolios, providing cleaner combustion and higher energy output, contributing to a more sustainable energy future [73].

9. Biofuel Regulations in the EU

Canola is the leading first-generation biodiesel feedstock in Europe, due to its economic and energetic performance [74], although as it has reached its efficiency plateau, it paved the way for the implementation of the second- and third-generation biofuels. EU policies—most notably the Renewable Energy Directive II (RED II)— shape the biofuel investment and research landscape, with the dual mandate to enhance the environmental performance of biofuels and to mitigate associated land-use impacts [75,76]. RED II establishes explicit targets, mandating that a minimum share of transportation energy originates from advanced biofuels or biogas. In doing so, it disadvantages first-generation biofuels like canola biodiesel. Specifically, the directive imposes rigorous sustainability benchmarks that emphasize lower greenhouse gas emissions and minimizing land-use risks. Such criteria have led to better market positioning and financial support for technologies that offer a higher potential for innovation, while relegating traditional vegetable oil-based biofuels to a marginal role [76]. Moreover, studies on investment potential within the emerging forest bioeconomy market highlight that policy-induced market signals are reshaping research and development priorities, contributing to a relative decline in canola biodiesel investments [77].

Despite the well-intentioned environmental and economic objectives of these regulatory measures, while these policies accelerate innovation in advanced biofuels, they may also hinder further technological advancement and market growth for canola-based biofuels. The stringent sustainability criteria, combined with targeted subsidies for advanced biofuels, create high entry barriers for first-generation biofuels. Consequently, investors might perceive canola biodiesel as a less attractive area for technology enhancement, although its improvements could potentially revitalize its competitiveness [75,76].

10. Discussion

Biofuel production has gained significant attention as a sustainable alternative to fossil fuels, driven by the need to reduce greenhouse gas emissions, increase energy security, and promote rural economic development. Biofuels can be produced from a variety of raw materials, including vegetable oils, animal fats, and used cooking oils. One of the most important raw materials for the production of biofuels in the form of biodiesel, especially in Europe, is canola oil [78]. It is preferred due to its high oil content and favorable fatty acid composition, resulting in biodiesel with excellent cold-flow properties and oxidative stability [79,80]. Producing biodiesel from canola oil involves several steps, including the extraction of the canola oil and subsequent transesterification with alcohols such as methanol or ethanol. Various studies have demonstrated the performance of canola oil in biodiesel production, with high conversion rates and favorable environmental profiles [81,82].

The research on canola biofuel to achieve energy security is rather limited, particularly given the increasing global interest in renewable energy. It may be no surprise, due to the inefficiencies of this energy source. The body of work is primarily driven by researchers from countries that are not major canola producers, potentially due to factors such as production costs, technological barriers, and competition with food security objectives. The betweenness analysis shows that energy security is a concern, but the development of novel, efficiency-improving technologies in this body of research may be stalled (see Figure 6 and Table 9), and it may be difficult to spark an interest in the further development of this technology.

While canola biodiesel continues to play a role in energy diversification, especially in Europe where canola/rape is a significant crop, its significance is declining due to competition from second- and third-generation biofuels, which are more economically viable and environmentally sustainable [1]. Moreover, life cycle analyses (LCA) have revealed drawbacks in canola biofuel’s environmental profile, such as higher land use and respiratory inorganic emissions compared to traditional diesel [39]. The expansion of energy crops requires careful assessment to address controversies regarding the use of resources in competition with food, such as land, water, and energy, while promoting environmental and socioeconomic sustainability [83,84,85,86]. Different agroecological areas have different agronomic practices [87,88] and are influenced by different biophysical factors [89]. This, in turn, affects the efficiency of biomass production. Studying the energy efficiency of the biofuel production system under various agroecological and agricultural practices plays a key role in the selection and optimization of technologies in each type of environment and the further use and future of biofuels.

Despite these challenges, economic research on canola biofuel production remains relevant. It enables improved resource management, identifying inefficiencies, optimizing production processes, and determining when to phase out unprofitable ventures to redirect investments toward more sustainable alternatives [90]. Even declining technologies may hold residual social or ecological value, justifying continued research to explore potential improvements or alternative applications [91]. Additionally, insights into material efficiency and the policy-driven dynamics of resource demand can guide the transition to more sustainable energy practices [92,93]. Therefore, while canola biofuel faces mounting competition and criticism, its study still contributes critical knowledge for informed decision-making and sustainable development.

11. Conclusions and Recommendations

The literature review showed that despite the decreasing role of canola in biofuel production, economic research into canola biofuel remains valuable, particularly in optimizing production, understanding its economic viability, and guiding transitions to alternative energy sources. However, the correlation analysis and Granger causality tests performed suggest that oil prices, as a factor, do not have a definitive causal relationship with the frequency of scientific publications on canola biofuels. This indicates that additional drivers, such as government policies, energy security strategies, and advancements in alternative biofuel technologies, are critical in shaping research trends. The immediate, “lag-less” research spikes suggest that some work could have been conducted (or that, to a certain degree, some price hikes may have been anticipated), but also that research may react rapidly to changing economic conditions, and that public debates around fuel prices could drive short-term research surges. This raises the question of whether canola biofuel research is strategic and long-term or if it is reactive and crisis-driven.

Given EU policies favoring advanced biofuels, further investment in canola biodiesel may be economically unsustainable. However, hybrid solutions—such as canola-waste biodiesel blends—may offer a transitionary role toward more sustainable and efficient biofuel feedstocks. Although canola biofuel has been pivotal in the early stages of renewable energy transitions, its future will likely depend on significant technological improvements, such as enhancing production efficiency and sustainability. Moreover, as energy policies increasingly emphasize advanced biofuels and sustainability, the role of canola in the energy mix may become more complementary than central. Continued research should focus on its optimization while concurrently exploring innovative biofuel technologies to ensure long-term sustainability and resilience in energy systems, yet for now, it makes an impression of a research field in decline, and may even be considered a dead-end.

A certain limitation of the research was the analysis of articles from only two scientific databases: Scopus and Web of Science (WoS). Although they belong to the basic reference databases and allow the formulation of conclusions from the analyses performed, they do not cover all important articles on the research topic. It is therefore advisable that subsequent analyses cover a broader group of studies. Continued research should focus on its optimization while concurrently exploring innovative biofuel technologies to ensure long-term sustainability and resilience in energy systems.