Introductory Chapter: Environmental Conditions of the Functioning of Biorefineries and Biorefinery Systems and Their Impact on the Circular Economy

1. Introduction

According to the assumptions contained in many scientific studies and reports, biorefinery systems should constitute a permanent element of the circular economy, because an important feature of these systems is the full use of various types of substances, mainly waste organic substances and their environmentally friendly processing into energy carriers and other products with added value. The basic diagram characterizing the basic value chain in the bioeconomy, consisting of the use of biorefinery systems, was developed already in 2013 and presented in Figure 1.

Figure 1.

Value chains in the bioeconomy [1].

The possible processes of processing waste raw materials through biorefinery systems shown in Figure 1 should be considered desirable and consistent with the principle of sustainable development. This compliance can be determined by monitoring these changes with the use of tools such as measures or indicators of sustainable development. These tools allow to determine the pace and scope of changes, as well as the effectiveness of the activities carried out. The measures are also intended to verify and objectify the goals set by the international community and individual countries [2].

2. Assessment indicators of the sustainable development in biorefinery systems

One of the first international organizations which attempt to develop a system of measures was the United Nations European Commission of Economy—UNECE. It developed a system of twelve measures, which were also assigned to twelve environmental problems. However, they did not fully reflect the complex and interdisciplinary nature of sustainable development.

Only the list of measures presented in the report “An Overview of Environmental Indicators, State of the Art and Perspectives”, developed under the United Nations Environment Program (UNEP), can be considered comprehensive and allows for the assessment of various aspects of sustainable development [3], as well as the measures included in two reports elaborated by the United Nations Commission on Sustainable on Sustainable—UNCSD:

• Indicators of Sustainable Development: Methodology Sheets (April–May 1996);

• Indicators of Sustainable Development: Framework and Methodologies (August 1996).

As part of the UNCSD program for the sustainable development indicator systems, a list of 130 indicators compiled under the cause-state-reaction scheme was developed [4].

On the cause side, one should look for those forms of human activity that directly or indirectly affect the sustainability of development. State indicators define the implementation of sustainable development, while response indicators show human activities (e.g. changes in environmental policy and others) in response to the challenges of sustainable development) [2].

The indicators developed by UNCSD are to be used in the environmental policies of individual UN member countries. They also provide a kind of background for the definition of national indicators. In order to facilitate this task, UNCSD has prepared a list of methodological recommendations for their construction, including, inter alia, the reference of the indicator to the Agenda 21 objectives or the relevance to the sustainable development policy [4].

The hope placed on the concept of biorefinery installations as an element contributing to the creation and ensuring of sustainable development made it necessary to introduce sustainability measures for the individual planning and design stages of such installations. Their complexity and multifaceted nature led to the derivation of a number of economic, environmental, and social indicators in this regard. The proposed indicators are often characterized by similarities as well as divergences, but they become useful when they are used as complementary measures. The system of indicators is constantly evolving, growing, and new methodologies are being proposed.

The environmental impact of biorefineries is significant in terms of climate change, eutrophication, water scarcity, land use, energy, and material depletion, as well as water pollution and toxicity. Several aspects can be categorized according to the type of biorefineries. Therefore, among a number of indicators characterizing sustainable development, one can list those that will be used in the analysis of the impact of biorefinery installations on the environment. These are the indicators:

• Process efficiency (energy conversion efficiency),

• Use of primary resources (accumulated primary energy, abiotic resources, land, clean water),

• Environmental impact (GHG emissions to the atmosphere, water eutrophication, soil acidification, potential for the formation of photochemical oxidants, emissions of toxic substances to water reservoirs and watercourses),

• Economic efficiency (income potential of biorefineries).

In the indicator methodology proposed by Sacramento-Rivero [5] sustainable development is mainly understood as a state of efficiency of a biorefinery in which the consumption of resources and the associated effects are at such a level that the biorefinery can operate successfully for an indefinite period with a limited environmental impact. This means that current human needs (those corresponding to the activities of biorefineries) are met without compromising the ability of future generations to meet their needs. It also means that the good performance of the assessment today may not be as good in the future if conditions change, for example if the legislation tightens the permitted emission levels or if agricultural yields start to decline.

A biorefinery is assumed to have a number of points where it is, is not sustainable to some degree. On this scale “0” represents the ideal state of sustainability, and “1” is the critical limit beyond which the installation becomes unsustainable. Consequently, the scale takes real values from zero to infinity, while sustainable development takes place with values from zero to one. The closer to zero, the more sustainable development is, while the closer to “1″, the more sustainable development decreases. Values greater than one mean unsustainable development (Figure 2).

Figure 2.

Sustainability scale—range of states of sustainability [5].

In this normalized sustainability scale, values from zero to one represent balanced states, while values equal to or greater than one represents unsustainable system operation. The state of ideal durability, in the conventional “0” point, is purely conceptual - it represents the ideal value of the indicator, in the absence of environmental impact (zero-emission), impossible to achieve in reality.

On the other hand, the critical value is the point “1” at which the system becomes unbalanced in the sense that it represents an excessive negative environmental impact relative to the reference system (e.g. conventional oil refinery) or is uneconomical. The “1” limit point is a moving point that depends on the ideal durability indicator and the critical value based on various factors, incl. Reference to national and international targets (e.g. reduction targets). For some indicators, this critical value will require periodic recalibration.

The critical limit value must be reliably established determined on a solid scientific basis and confirmed by national or international targets, agreements, or certification bodies. The selection of the appropriate critical value will depend on the results of the Life Cycle Assessment (LCA) of the installation and its products and the sustainability assessment taking into account the definition of the indicator. When at least two sources propose different critical values, the general recommendation is to choose the most stringent criterion, in line with the precautionary principle.

Using the example of the indicator: “Reduction of greenhouse gas (GHG) emissions”, an ideal system would not emit greenhouse gases (this state would be described by a zero value on a normalized scale), and the system at the critical limit point would be one that releases exactly the amount of greenhouse gases, which the atmosphere is able to take without reaching a catastrophic rise in temperature. Due to the complexity of determining the above, the critical reduction of greenhouse gas emissions would be the one required by the appropriately adopted target (e.g. the reduction target), the benchmark should be the results achieved by the reference system. Therefore, if a biorefinery is designed for a country belonging to the European Union (EU), then the reduction targets, and thus the critical (border) reduction value, will be determined on the basis of the currently applicable RED II (Renewable Energy Directive) on renewable energy sources. In the RED II Directive [6], the level of reduction of greenhouse gas emissions is min. 65% for installations launched after 01/01/2021 and min. 70% for renewable fuels of nonbiological origin. In this case, where two objectives apply to the designed biorefinery, the critical value should be established according to more stringent regulations.

3. Sustainable development criteria in the field of energy carriers as biorefinery products

The European RED Directive establishes sustainability criteria, which were then revised and tightened up in RED II in Article 29 (1). 2–8 and 10. They read as follows:

• Biofuels produced must not come from raw materials obtained from land with high biodiversity (i.e. primeval forests and other wooded lands, protected areas, grassland with high biodiversity),

• Produced biofuels cannot come from raw materials obtained from land rich in carbon (i.e. wetlands, wooded areas, peatlands),

• Agricultural raw materials grown in the EU and used for the production of biofuels should be obtained in compliance with minimum requirements concerning good agriculture culture in accordance with environmental protection and with certain statutory management requirements set out in the Common Agricultural Policy,

• The greenhouse gas emission savings through the use of biofuels, bioliquids, and biomass fuels should be at least 50%, 60%, and 65% respectively for biofuels, biogas consumed in the transport sector, and bioliquids produced in installations put into operation before October 5, 2015, before December 31, 2020, and after January 1, 2021.

Although biofuels are very important from the point of view of reducing greenhouse gas emissions in EU countries, it should be borne in mind that the production of currently known and used biofuels usually takes place using arable land that was previously used for other agricultural purposes, such as food or feed production. These are the so-called first-generation biofuels (conventional biofuels). Since agricultural production for food is and will remain necessary, it can lead to the expansion of food crops to land that has not been cultivated so far, thus including high-carbon areas such as forests, wetlands, and peatlands. Indirect Land Use Change (ILUC)—as the above-described process is called—can cause the release of CO₂ stored in trees and soil, which may counteract the process of reducing greenhouse gas emissions resulting from the increase in the share of biofuels. To tackle the ILUC issue in the “Clean Energy for All Europeans” package [7], the revised Renewable Energy Directive introduces a new approach. It sets limits for biofuels, bioliquids, and biomass fuels with a high ILUC risk, with significant expansion in areas with high carbon content. These limits will have an impact on the amount of these fuels that the Member States can count toward meeting their national targets when calculating the total national share of renewables and the share of renewables in transport. EU Member States will still be able to use (and import) fuels that fall under these limits, but will not be able to take these amounts into account when calculating the extent to which they have met their renewable energy targets. The limits in question are to be frozen in the period 2021–2023 at the 2019 levels, and then until the end of 2030, the limit is gradually reduced to 0%.

RED II also introduces an exemption from these limits for biofuels, bioliquids, and biomass fuels certified as having a low ILUC risk. In order to implement this approach, as required by the Directive, the Commission has adopted Delegated Regulation (EU) 2019/807.

According to the current target by 2030, at least 14% of transport fuels are to come from renewable sources, with first-generation ILUC-risk biofuels no longer counting toward the EU’s renewable energy targets from 2030. As a part of this goal has been set a target for advanced biofuels produced from feedstocks listed in Part A of Annex IX. The share of advanced biofuels and biogas produced from raw materials listed in Part A of Annex IX to the Directive (biofuels and biogas with low ILUC risk) as a share of final energy consumption in the transport sector will be at least 0.2% in 2022, at least 1% in 2025 and at least 3.5% in 2030.

Member States of the European Union may exempt fuels suppliers that supplying fuels in the form of electricity or renewable liquid and gaseous transport fuels of nonbiological origin—with regard to these fuels—from the requirement to achieve a minimum share of advanced biofuels and biogas produced from raw materials listed in Annex IX, Part A.

Raw materials for the production of biogas for transport and advanced biofuels, the share of which in the minimum shares referred to in Art. 25 Section 1, the first and fourth paragraphs, can be considered as twice their energy value.

The share of biofuels and bioliquids, as well as biomass fuels used in transport, if produced from food and feed crops, may not be higher than by one percentage point than the share of these fuels in final energy consumption in transport and rail transport sectors in 2020, with a maximum of 7% of energy consumption in the road and rail transport sectors in Member State.

Fuels produced from high-risk ILUC raw materials will be constrained by a stricter consumption cap in 2019. The share of biofuels, bioliquids, or biomass fuels with a high indirect land-use change risk, produced from food and forage crops, where the significant expansion of the production area into carbon-rich land shall not exceed the consumption of such fuels in the Member State in 2019, unless they are certified as biofuels, bioliquids or biomass fuels with a low risk of indirect land-use change. From 31 December 2023 to 31 December 2030 at the latest, this limit will be gradually reduced to 0%.

In relation to the changes introduced by the currently applicable RED II directive, it is reasonable to use raw materials with a waste status in biorefinery production from various industries (agriculture, food, livestock, etc.), catering waste, or, for example, out-of-date food products. The use of this type of raw material is also supported by a significant reduction in emissions in the life cycle of the biorefinery system, resulting from the avoidance of the need to use the land for the cultivation of the raw material and all processes related to sowing, harvesting and transporting the raw material to the biorefineries.

Therefore, biorefinery installations will undoubtedly contribute to the more ambitious target of a 55% reduction in greenhouse gas emissions by 2030 [7], forecasted in the Climate Goals Plan [8] in the frame of the European Green Deal [9].

4. Conclusions

In the light of the latest regulations, the indicators analysis for biorefineries comes down to the calculation of the emission factor for the full life cycle of a biorefinery product, which is a biofuel/biocarbon biocomponent. For chemicals and other value-added products, comparisons can be made by assessing the LCA of non-biorefinery product equivalents. The emission factor defines the possibility of using a fuel/biofuel or a product with an added value on the market, and thanks to this indicator it can be assessed whether this fuel or product actively participates in the achievement of the reduction target. However, it should be noted that in 2021 the concept of petrosynthesis [10] appeared as a series of complex technological processes using mainly the final products of combustion, such as carbon dioxide and water (water vapor), and other greenhouse gases using energy from renewable sources generating electricity, to the production of hydrocarbons and their compositions which are equivalent to products manufactured so far by the refining and petrochemical industries. According to its author, this concept is a practically possible substitute for photosynthesis processes, as it was shown in Figure 3.

Figure 3.

Simplified models of petrosynthesis and photosynthesis [10].

The concept presented in Figure 3 may partially complement the processes carried out by comprehensive biorefinery systems, allowing for the full use of all possible post-process waste, including water and carbon dioxide, in the so-called closed cycle. However, the actual implementation of this concept requires further work, especially in the field of obtaining waste carbon dioxide from dispersed processes and hydrogen directly from industrial, municipal, and salt waters, as well as from other sources, which is related to the increasing shortages of water necessary for biological processes, in including drinking water.