3.1. Economic sustainability
The economic sustainability of a product or activity is evaluated by finding a balance between the total costs of production, distribution and consumption for the analyzed product or activity and the benefits obtained after that product is activity used. This balance is used to create a range of grades of sustainability: high, medium, low or no sustainability.
Romania has a very high potential for biodiesel production. A report published by the Ministry of Agriculture  shows that Romania has a total of 13.3 million ha agricultural land, with arable land representing 8.3 million ha. Taking into account that in Romania, biodiesel is solely produced from rapeseed oil, it is important to analyze the degree of arable land utilization for rape crops, the main feedstock for rapeseed oil production. The surfaces cultivated with rape crops are presented in Fig. 1.
Furthermore, total rapeseed production (yellow block) and price (blue line) on the internal market for the period 2017–2019 are shown in Fig. 2.
In 2018, the total land cultivated with rape crops was 1,610.9 thousand ha, but it dramatically decreased in 2019 to 798.2 thousand ha (Figure 1), representing a reduction of 50.45%. Taking into consideration that the entire quantity of rapeseed is used to extract rapeseed oil – the feedstock for the biodiesel produced in Romania – we believe that this significant decline in rapeseed production was a reaction to the biodiesel market, which came to prefer importing biodiesel instead of producing it in Romania. This can be regarded as a negative indicator of biodiesel sustainability in Romania.
Another aspect that we deem very important when assessing biodiesel’s economic sustainability is its cost of production. To calculate this cost, we need to take into consideration all costs, starting with the agricultural costs for rapeseed crops, followed by oil extraction and biodiesel synthesis. All these costs are then corrected with secondary activity costs, such as for fuel for transportation and distribution. Finally, we transform these costs into a production price of biodiesel for the internal market. The total costs of biodiesel production in Romania are presented in Table 2.
Considering that the excise duty to pay for biodiesel is the same as that for gas oil (almost 300 euro/t), the final price for the internal market exceeds 1,000 euro/t biodiesel. This price is far from competitive with the biodiesel purchased on the external market .
The calculated price for biodiesel production in Romania shows a low level of economic sustainability. Indeed, even though the agricultural potential for biodiesel production is quite high, the overall score for biodiesel sustainability is only 2, according to the data presented in Table 1.
3.2. Environmental sustainability
The environmental sustainability of biodiesel as a component of the Romanian fuel pool is evaluated by a methodology developed by Rojnavschi , based on calculating the Global Impact Index (GII). In our case, the GII is calculated by assessing biodiesel’s impact on environmental factors (i.e. air, water and soil) as well as on the biodiversity of natural systems. This environmental impact assessment is based on quality indicators that accurately reflect the state of environmental factors. The quality of any environmental element or factor is estimated by transforming the qualitative aspects into quantitative parameters. This transformation is undertaken using a mathematical equation, as follows:
For the qualitative assessment, quality indicators of each environmental factor at a given moment are placed on a reliability scale with different grades expressing the proximity of the evaluated situation to the ideal state (Table 3).
Biodiesel’s impact on the environment is assessed using an evaluation matrix, where the potential interactions between the effects of biodiesel usage and environmental components are quantified as effect sizes (± E) using the evaluation mtrix. With these effect sizes, we can calculate the quality index (Iq) and then estimate the Reliability Grade (RG) of each environmental element. The RGs express the degradation of each environmental factor affected by biodiesel usage.
Recent studies [18, 19] have shown that biodiesel production via the transesterification of vegetable oils is realized in production units based outside urban areas and that the distribution of biodiesel does not pose a contamination risk for soil and water. Furthermore, the agricultural chain for rapeseed crops has a very low impact on the environmental factors of soil, water and air. In addition, we have already shown that in Romania, the terrain cultivated with rape crops constitutes only 2.25% of the total agricultural land, hence biodiversity is scarcely affected. Regarding the effects of biodiesel combustion, there are no reports of significant emissions of pollutants into the atmosphere. Compared with diesel fuel, biodiesel produces lower exhaust emissions of particulate matter (PM), carbon monoxide (CO) and volatile organic compounds (VOCs), but higher nitrogen oxide (NOx) emissions [4, 20, 21]. Regarding the global warming potential of biodiesel from rapeseed oil, a value of 44 carbon dioxide (CO2) eq. MJ-1 has been reported, which is nearly half that of diesel fuel (94 CO2 eq. MJ-1) . However, in the case of biodiesel blends, when the blending ratio is under 10%, the air quality impact can be considered negligible [20, 21]. More than that, Chauhan and Shukla  have shown that biodiesel blending at a volume below 10% has a minimal impact on the environmental factors of soil and water.
Nevertheless we assess the air quality that may be affected by exhaust emissions containing CO2, CO, NOx, PM and VOCs. Our procedure is to divide the assessment into a multi-directional analysis concerning the influence of each chemical compound emitted in the environment. The evaluation matrix for calculating the impact of biodiesel blended with diesel fuel at a 7% volume is presented in Table 4.
The environmental impact of biodiesel production and combustion was quantified in concordance with the environmental effects (Table 2) and the quality index calculated using equation 2. Furthermore, the environmental impact on the air is calculated in Table 5 and on all the environmental factors in Table 6.
The GII of biodiesel production and combustion in Romania is calculated by dividing the surface obtained by the RG for the ideal state of the environment (noted with SI) by the surface for the RG for the real state of the environment (noted with SR), as presented in Fig. 3 and calculated with Equation (3).
The equation for calculating the GII is as follows:
And the evaluation scale for GII has the following levels:
GII = 1 – natural environment not affected by human activity;
GII = 1 ÷ 2 – environment submitted to the effects of human activity within the allowable limits;
GII = 2 ÷ 3 - environment submitted to the effects of human activity causing a state of discomfort to all the
forms of life;
GII = 3 ÷ 4 - environment affected by human activity disturbing the life;
GII = 4 ÷ 6 - environment seriously affected by human activity;
GII > 6 – degraded environment unsuitable for the life.
For biodiesel production and combustion in Romania, the GII is calculated with Equation (3) using the RG values from Table 6, as: RG soil = 10; RG water = 10; RG air = 9; and RG biodiversity = 10. Thus, the area for the ideal state is SI = 200 units while for the real state it is SR = 190 units, resulting in a GII of 1.05, corresponding to an environment that is not significantly affected by biodiesel production and combustion.
All these data show the very high sustainability of biodiesel production and combustion in Romania, the score for which, according to Table 1, is 4.
3.3. Social sustainability
As stated by Kolk , the social sustainability of an activity or product refers to its ability to create favourable conditions for the community to ensure all that is necessary for living. Other studies [24, 25] have contended that social sustainability concerns more than basic necessities, such as human rights, gender equality, public participation and rule of law, all of which promote peace and social stability. Regarding biodiesel production, we have already shown the significant decline in Romanian interest in energy crops and especially rape crops, hence in this situation, the level of social sustainability is very low. Biodiesel synthesis is connected with the reduction in rapeseed oil production and so sustainability will remain at a low level. Because the combustion of biodiesel is only important for the environment (having no social effect), here we solely take into consideration biodiesel production for the social sustainability assessment. Finally, having in view the poor level of biodiesel production in Romania, we can see that social sustainability here is modest, yielding a score of 1 (Table 1).
3.4. Biodiesel sustainability calculation
Biodiesel sustainability will be calculated with equation 1, using the scores obtained for economic, environmental and social sustainability adjusted with the influence factors. The result is presented in Table 7.
The score obtained in Table 7 shows the low sustainability of biodiesel production and combustion in Romania, as a result of the very poor levels of economic and social sustainability. The total score corresponds to a low level of sustainability, even though the degree of environmental sustainability is high.
In analyzing this situation, we have identified a number of contributing factors that can be summarized as follows:
- The most important factor is the Romanian government’s strategy, which has not supported the development of biodiesel production through granting fiscal aids to rapeseed producers and by reducing excise duties;
- The second factor is the influence of the international market, which offers large quantities of biodiesel at lower prices than the biodiesel produced in Romania. Countries such as Russia, China, Malaysia and Indonesia, which use palm oil for biodiesel synthesis, offer very attractive biodiesel prices, causing production in Romania to decline;
- A final factor that is specific to Romanian industry is the fact that all the refineries in the country are owned by foreign companies. Thus, there is little Romanian participation in the industry, with the result that each refinery purchases biodiesel from its owner’s zone of influence. Therefore, Petrotel Lukoil Refinery (owner: Lukoil, Russia) purchases biodiesel from Eastern European countries like Russia, Ukraine and Moldova, but also from the above-mentioned Asian countries. Rompetrol Refinery (owner: KazMunayGas, Kazakhstan) applies a similar strategy to import biodiesel from the Asian market. A third refinery, Petrobrazi (owner: OMV, Austria), looks abroad to seek the cheapest price in order to increase its profits.
The future of biodiesel in Romania is connected to the EU strategy regarding the utilization of renewable fuels. Even if the biodiesel blending ratio were to be maintained or increased, the prognosis is not favourable, because the Romanian agricultural strategy is to reduce energy croplands so that they can be used instead for food products to satisfy the growing demand of the national and international markets. Support for this prognosis is provided by Eurostat statistics  indicating that Romania is the biggest producer of maize in Europe, a position that will be sustained in the coming years. Another aspect of the future of biodiesel, not only in Romania but also worldwide, is the rise of electric cars, which will replace diesel engines and thus have a direct effect on biodiesel consumption. All these aspects support our forecast that biodiesel production and consumption will remain at a very low level in Romania in the next decade.