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Aviation contributes to anthropogenic climate change mainly by contrails, CO2 and NOx emissions, whereof contrails are considered the largest single contributor to the radiative forcing from aviation. Powering aircraft with kerosene containing fewer or no-aromatics, i.e., “Sustainable Aviation Fuels” (SAF) or hydroprocessed, fossil-based kerosene, can significantly reduce contrail climate forcing. However, such kerosene is currently scarcely available. Moreover, less than 10 % of the flights worldwide cause more than 80 % of the contrail climate forcing. Hence, this study investigates a targeted allocation of paraffinic, i.e., aromatics-free kerosene to flights and flight segments with the highest contrail climate forcing, by calculating the resulting contrail energy forcing (in J) on 844 364 flight trajectories worldwide departing from five large European airports in 2019.The contrail radiative forcing integrated over contrail evolution (i.e., contrail energy forcing [J]) is simulated for a reference fleet powered with conventional kerosene of 14.1 m - % hydrogen content. 5 % of overall kerosene demand assumed to be paraffinic kerosene with 15.3 m - % hydrogen content is allocated via a uniform, a flight-specific and a segment-specific approach. The uniform allocation assumes that all flights receive the same blend of 5 % paraffinic kerosene. The other cases target 100 % paraffinic kerosene either to flights or segments with highest contrail energy forcing. Compared to the reference, the results indicate a reduction on contrail energy forcing by 4 %, 36 % and 55 %, respectively. For market shares of paraffinic kerosene up to 30 %, a segment specific allocation appears advantageous compared to a flight specific allocation. However, they might require airport and aircraft modifications. Uncertainties in contrail climate benefits can be reduced by providing additional information on kerosene properties and accurate meteorological data. Overall, this study highlights robust potentials of paraffinic kerosene to significantly reduce the climate forcing from aviation.

The objective of this study is to systematically investigate not only the influence of different additive types—beyond the much-considered case of aluminum-silicate-based additives—but also to carry out an additional comparison between primary and secondary emission mitigation measures during small-scale wood-chip combustion. Hence, combustion trials are realized within a 33-kW combustion plant. Pine wood chips additivated with 1.0 wt%a.r. of four additives have shown promising emission reduction effects in the past; namely kaolin (i.e., aluminum-silicate-based), anorthite (i.e., aluminum-silicate- and calcium-based), aluminum hydroxide (i.e., aluminum-based), and titanium dioxide (i.e., titanium-based). In addition to the primary mitigation measure (i.e., (fuel) additivation), an electrostatic precipitator (ESP) as a common secondary mitigation measure for total particulate matter (TPM) reduction is used for comparison. In addition to standard analyses (e.g., gravimetric determination of TPM emissions), an extended methodology (e.g., characterization of the elemental composition and ultrafine particle fraction of TPM emissions) is applied. The results show that the additivation of wood chips with kaolin and anorthite can lead to an operation of the combustion plant in compliance with the German legal TPM limit values by undercutting the absolute emission level achievable by the ESP. Additionally, kaolin and anorthite achieve significant reductions in carbon monoxide (CO) emissions, while kaolin simultaneously, and similarly to ESP, also leads to a shift in the particle size number distribution of PM emissions towards coarser particles. All additives show a significant reduction of potassium (K) emissions by the formation of high-temperature stable K compounds in the resulting ashes.

The need to limit anthropogenic climate change to 1.5–2 °C, as agreed in the Paris Agreement, requires a significant reduction of CO2 emissions resulting from the use of fossil carbon. However, based on current knowledge, carbon is expected to remain crucial in certain industrial sectors, e.g., the chemical industry. Consequently, it is essential to identify and utilize sustainable carbon sources in the future. In this context, various carbon sources were examined and classified in terms of their disruption of the Earth’s (fast) carbon cycle. Furthermore, the examined carbon sources were qualitatively analyzed with regard to their technical readiness level, their energy expenditure, and their current and future availability, as well as legal regulation within the European Union. As a result, only biogenic and mixed carbon from the ambient air can be considered genuinely sustainable within the Earth’s (fast) carbon cycle. Mixed carbon streams, e.g., from waste recycling, fall into a gray area. The same applies to certain process-related emissions that originally descend from fossil fuel energy. In terms of energy considerations, technical maturity, and exploitable potentials, prioritizing the utilization of biogenic carbon sources is advisable for the time being, especially for CO2 produced as a by-product originating from biogenic carbon carriers.

Abstract Aim Stillage, the main residue from cereal-based bioethanol production, offers a great potential for the recovery of pentosan-type carbohydrates. Therefore, potential process options for the recovery of pentosans from bioethanol thin stillage are investigated and their basic feasibility is demonstrated on a laboratory scale. Findings The main result of this work is the development of a three-stage process for pentosan recovery, including solid–liquid separation, pentosan solubilisation and purification. The pentosan content of the thin stillage used here was determined to be about 14% related to dry matter (DM). By means of solid–liquid separation, these pentosans accumulate in the liquid phase (up to 80%), while the remainder (about 20%) is found in the solid phase. Solubilisation of these insoluble pentosans was achieved by using either a hydrothermal, an alkaline or an enzymatic treatment. Here, the results indicate a maximum solubilisation yield of 90% with a hydrothermal treatment using liquid hot water at 180 °C. Ultrafiltration and precipitation are investigated for purification. The most promising process option in this study is solid–liquid separation followed by ultrafiltration. In this case, the total pentosan yield is assessed to be about 48% (based on thin stillage) with a final pentosan concentration of about 30%DM. Graphical Abstract

Aviation contributes about 4 % of global anthropogenic climate forcing primarily by contrails, CO2 and NOx emissions. Renewably sourced aviation kerosene can help to reduce the climate impact from CO2 and from contrails, but so far, its production capacities are very small. Hence, the climate impact of using fossil fuel-based kerosene with a hydrogen content increased by hydroprocessing as short term mitigation measure is studied here. Therefore, the change in net energy forcing (ΔEFnet) in 2019 is calculated as the sum of the change in contrail energy forcing (ΔEFcontrail) and additional CO2 emissions (ΔEFhydroprocessing) from aviation kerosene hydroprocessing (ΔEFnet = ΔEFcontrail + ΔEFhydroprocessing). The results show that hydroprocessed aviation kerosene can reduce the net energy forcing EFnet by about 33 % with ΔEFhydroprocessing penalty of 5 %-points. Increasing the hydroprocessing severity increases the relative climate benefit, which is only slightly affected by the emissions factor for hydroprocessing or the choice of the time horizon. Data limitations about fuel composition and its effect on contrails and climate cause considerable uncertainties and the fuel's compliance with specification standards needs consideration. This study on the climate effect of hydroprocessed fossil kerosene can help to assess near-term measures to reduce the climate impact from aviation.

One option to reduce greenhouse gas (GHG) emissions from heavy-duty vehicles is switching to hydrogen as a fuel, which is converted in drive trains powered by fuel cells. In addition to the production of new hydrogen trucks, it is also possible to convert used diesel-powered trucks to hydrogen-powered vehicles.This paper aims to evaluate the environmental impact of a heavy-duty truck converted from diesel propulsion to a hydrogen fuel cell drive regarding life-cycle GHG emissions and mineral resource scarcity (MRS). This life cycle assessment focuses on the construction and end-of-life phases of the vehicle (first part) and on the entire life cycle, including the use phase (second part).The largest share of GHG emissions for the hydrogen-powered truck (first part) originates from the tank system and the chassis, specifically due to the materials reinforced plastics, steel, and aluminum. The fuel cell system is responsible for half of the MRS, mainly due to the used platinum, which, as well as steel, accounts for about one-third of the MRS.The hydrogen supply path is the most crucial factor determining the overall GHG emissions (second part). To reduce GHG emissions compared to a conventional diesel-driven truck, the share of renewable energy within the power mix has to be at least 61 %. The MRS increases with an increasing share of renewable energy within the power mix.To reduce GHG emission of a converted hydrogen-powered truck, the use of reinforced plastics and platinum should be minimized, thus contributing to more efficient use of mineral resources.

In order to achieve the goal of limiting global warming to 1.5 °C, also the growing aviation industry needs to take measures to reduce their greenhouse gas emissions. Various renewably sourced aviation fuels can significantly reduce greenhouse gas emissions and most of them, except for example liquid hydrogen or LNG, can be used in the existing infrastructure without airport or aircraft modifications. As most of these renewably sourced fuel types are not (yet) produced at commercial scale, many technological assessment parameter (e.g. carbon or energy efficiency) are uncertain. Thus, the goal of this study is to compare two different process routes, both being based on biochemical and thermochemical conversion steps. The processes evaluated against conversion efficiency of the available raw feedstock and process energy requirements. The evaluation uses theoretical and biochemical carbon efficiency as well as energy efficiency as indicators. A steady-state flowsheet simulation for two biogenic process paths via biogas and bioethanol as intermediate products is carried out on the basis of literature data. In addition, the optional use of solid residue from the biotechnological process step by combustion for direct heat supply cases are studied. In the ethanol-based route, about 23% of the carbon in the feed can be recovered as kerosene, whereas this is only about 19% in the biogas route. Simultaneously, the ethanol-based route without the combustion of the residue has an energy efficiency of 28%, while the biogas route has an efficiency of 24%.

From a cost and sustainability perspective, the use of by-products such as rye bran in sow diets is of particular interest. Rye bran has valuable ingredients that have potential benefits for the gut health of sows. The aim of this study was to investigate the effects of including 15% rye bran in the sows’ feed on the performance of sows and piglets. The feeding started one week before the farrowing date and ended at weaning. Performance was evaluated by measuring sow (n = 175) and piglet body weight (n = 1372) and sows’ backfat thickness (n = 80). These data were additionally used to calculate the colostrum intake of the suckling piglets and the sows’ milk production. It was found that there were no differences in the performance parameters between the experimental and control groups. However, this study showed that the piglets with light birth weight (LBW (

The nutritional benefits of rye (and therefore rye bran) are mainly due to its high content of fermentable dietary fiber, the non-starch polysaccharides (NSP). Microorganisms in the large intestine are able to convert these into short-chain fatty acids (SCFA), including butyrate. Butyrate strengthens the epithelial barrier function in the colon by nourishing the enterocytes and inhibiting the spread of Salmonella in the intestinal tract. Therefore, the aim of this study was to test under field conditions whether a diet with rye or rye bran as the main ingredient for gilts, sows, and weaned piglets is associated with a lower Salmonella prevalence. Depending on the age groups, between 20–30% rye or between 15–20% rye bran was used in the experimental group. A total of n = 1983 boot swabs, n = 356 fecal samples, and n = 1909 serum samples were examined. The results of this study show that rye or rye bran at the levels used had no apparent effect on the number of positive Salmonella samples. However, the Salmonella OD values in the experimental groups were significantly lower than in the control group. This suggests that the use of rye leads to a lower incidence of infection, but this effect could not be proven from swabs.

Abstract The shift from straw incorporation to biofuel production entails emissions from production, changes in soil organic carbon (SOC) and through the provision of (co‐)products and entailed displacement effects. This paper analyses changes in greenhouse gas (GHG) emissions arising from the shift from straw incorporation to biomethane and bioethanol production. The biomethane concept comprises comminution, anaerobic digestion and amine washing. It additionally provides an organic fertilizer. Bioethanol production comprises energetic use of lignin, steam explosion, enzymatic hydrolysis and co‐fermentation. Additionally, feed is provided. A detailed consequential GHG balance with in‐depth focus on the time dependency of emissions is conducted: (a) the change in the atmospheric load of emissions arising from the change in the temporal occurrence of emissions comparing two steady states (before the shift and once a new steady state has established); and (b) the annual change in overall emissions over time starting from the shift are assessed. The shift from straw incorporation to biomethane production results in net changes in GHG emissions of (a) −979 (−436 to −1,654) and (b) −955 (−220 to −1,623) kg CO2‐eq. per tdry matter straw converted to biomethane (minimum and maximum). The shift to bioethanol production results in net changes of (a) −409 (−107 to −610) and (b) −361 (57 to −603) kg CO2‐eq. per tdry matter straw converted to bioethanol. If the atmospheric load of emissions arising from different timing of emissions is neglected in case (a), the change in GHG emissions differs by up to 54%. Case (b) reveals carbon payback times of 0 (0–49) and 19 (1–100) years in case of biomethane and bioethanol production, respectively. These results demonstrate that the detailed inclusion of temporal aspects into GHG balances is required to get a comprehensive understanding of changes in GHG emissions induced by the introduction of advanced biofuels from agricultural residues.

This study investigates the transferability of aluminum-silicate-based fuel additivation as a primary, fuel-based mitigation measure for inorganic alkali-based particulate matter (PM) emissions during the complete combustion of wood chips. Therefore, wood chips are additivated with 0.5 wt% of three different types of the aluminum-silicate-based additive kaolin, which differ mainly in their particle size distribution, and with one type of kaolinite. The subsequent combustion trials with non-additivated and additivated wood chips are carried out in a small-scale combustion plant. To evaluate the effect of the additivation of the wood chips, the total particulate matter (TPM) emissions, the potassium (K) emissions, the ultra-fine PM emissions and the carbon monoxide (CO) emissions, as well as the chemical composition of the resulting ashes, are analyzed. In order to compare the primary, fuel-side mitigation measure of fuel additivation with the established secondary mitigation measures, an electrostatic precipitator (ESP) is additionally utilized. The respective result shows that the aluminum-silicate-based fuel additivation of the wood chips with kaolin and the use of the ESP lead to comparable reductions in the TPM emissions, as well as the share of the ultra-fine particle fraction in the PM emissions. The addition of the additive kaolin additionally causes the significant mitigation of the K and CO emissions. Overall, the obtained results suggest that the combined utilization of fuel-side aluminum-silicate-based fuel additivation, together with the secondary mitigation measure of the ESP, might be very promising to further reduce PM emissions from combustion devices that operate with wood chips.

MENA countries published national policy targets for the implementation of electricity from renewable energy (RE). These targets are important as they serve as framework for stakeholders in the energy sector like businesses and administration, while also showing governmental ambitions to the public. This paper investigates the impact on resources, generation cost and GHG emissions if the targets are met. It also examines whether the current development is achieving the targets and how the targets perform in the light of the Paris Agreement. 13 to 52 % of electricity from RE is targeted for 2030. The necessary RE expansion exceeds the current expansion in most countries. Only in Morocco and Jordan are projects indicating that the targets might be reached. From a resource perspective, a much stronger expansion is possible. Beneficial locations exist allowing to cover the domestic demand or even an export of electrical energy or derived energy carrier. Furthermore, especially PV, but also wind systems, can generate electricity in many areas for lower cost than fossil fuel fired power plants. Specific GHG emissions of national electricity production in 2017 are estimated to 396–682 gCO2e/kWh and decrease to 341–514 gCO2e/kWh if the 2030 RE targets are met. The type of fossil fuel has a strong impact on the GHG emissions. Although Morocco has highest RE deployment today and targets highest RE share in 2030, it shows today and in 2030 specific GHG emissions that are among the highest of considered MENA countries because electricity production from coal dominates whereas other countries use mainly natural gas. Existing policy targets decrease specific GHG emissions until 2030. However, stronger GHG mitigation efforts will be necessary afterwards in order to reach targets of the Paris Agreement. More ambitious 2030 policy target would distribute the load more evenly over time and should be reconsidered.

In industrial-scale biogas production from cereal straw, large quantities of solid fiber-rich digestate are produced as residual material. These residues usually contain high amounts of cellulose, hemicellulose and lignin and thus have potential for further utilization. However, they also contain impurities such as ammonia and minerals, which could negatively affect further utilization. Against this background, the present study investigates how this fibrous straw digestate can be fractionated by a combined hydrothermal and enzymatic treatment and what influence the impurities have in this process. Therefore, it is analyzed how the fractions cellulose, hemicellulose and lignin are modified by this two-stage treatment, using either raw digestate (including all impurities) or washed digestate (containing only purified fibers) as the substrate. For both substrates, around 50% of the hemicellulose is solubilized to xylans after 50 min of hydrothermal treatment using steam at 180 ∘C. Furthermore, by subsequent enzymatic treatment, around 90% and 92% of the cellulose and hemicellulose still contained in the solids are hydrolyzed to glucose and xylose, respectively. Lignin accumulates in the remaining solid but structurally degrades during the hydrothermal treatment, which is indicated by decreasing ether and ester bond contents with increasing treatment times. Impurities contained within the raw digestate do not hinder this fractionation; they even seem to positively affect hemicellulose and cellulose valorization, but apparently lead to a slightly higher lignin degradation.

Hydrogen can be produced from the decomposition of methane (also called pyrolysis). Many studies assume that this process emits few greenhouse gas (GHG) because the reaction from methane to hydrogen yields only solid carbon and no CO2. This paper assesses the life-cycle GHG emissions and the levelized costs for hydrogen provision from methane decomposition in three configurations (plasma, molten metal, and thermal gas). The results of these configurations are then compared to electrolysis and steam methane reforming (SMR) with and without CO2 capture and storage (CCS). Under the global natural gas supply chain conditions, hydrogen from methane decomposition still causes significant GHG emissions between 43 and 97 g CO2-eq./MJ. The bandwidth is predominately determined by the energy source providing the process heat, i.e. the lowest emissions are caused by the plasma system using renewable electricity. This configuration shows lower GHG emissions compared to the “classical” SMR (99 g CO2-eq./MJ) but similar emissions to the SMR with CCS (46 g CO2-eq./MJ). However, only electrolysis powered with renewable electricity leads to very low GHG emissions (3 g CO2-eq./MJ). Overall, the natural gas supply is a decisive factor in determining GHG emissions. A natural gas supply with below-global average GHG emissions can lead to lower GHG emissions of all methane decomposition configurations compared to SMR. Methane decomposition systems (1.6 to 2.2 €/kg H2) produce hydrogen at costs substantially higher compared to SMR (1.0 to 1.2 €/kg) but lower than electrolyser (2.5 to 3.0 €/kg). SMR with CCS has the lowest CO2 abatement costs (24 €/t CO2-eq., other > 141 €/t CO2-eq.). Finally, fuels derived from different hydrogen supply options are assessed. Substantially lower GHG emissions, compared to the fossil reference (natural gas and diesel/gasoline), are only possible if hydrogen from electrolysis powered by renewable energy is used (>90% less). The other hydrogen pathways cause only slightly lower or even higher GHG emissions.

This study aims to develop a controller to operate an energy system-consisting of a photovoltaic thermal (PVT) system combined with a heat pump, using the reinforcement learning approach to minimize the operating costs of the system. For this, the flow rate of the cooling fluid pumped through the PVT system is controlled. This flow rate determines the temperature increase of the cooling fluid while reducing the temperature of the PVT system. The heated-up cooling fluid is used to improve the heat pump’s coefficient of performance (COP). For optimizing the operation costs of such a system, first an extensive simulation model has been developed. Based on this technical model, a controller has been developed using the reinforcement learning approach to allow for a cost-efficient control of the flow rate. The results show that a successfully trained control unit based on the reinforcement learning approach can reduce the operating costs with an independent validation dataset. For the case study presented here, based on the implemented methodological approach, including hyperparameter optimization, the operating costs of the investigated energy system can be reduced by more than 4% in the training dataset and by close to 3% in the validation dataset.

While bio-based but chemically synthesized polymers such as polylactic acid require industrial conditions for biodegradation, protein-based materials are home compostable and show high potential for disposable products that are not collected. However, so far, such materials lack in their mechanical properties to reach the requirements for, e.g., packaging applications. Relevant measures for such a modification of protein-based materials are plasticization and cross-linking; the former increasing the elasticity and the latter the tensile strength of the polymer matrix. The assessment shows that compared to other polymers, the major bottleneck of proteins is their complex structure, which can, if developed accordingly, be used to design materials with desired functional properties. Chemicals can act as cross-linkers but require controlled reaction conditions. Physical methods such as heat curing and radiation show higher effectiveness but are not easy to control and can even damage the polymer backbone. Concerning plasticization, effectiveness and compatibility follow opposite trends due to weak interactions between the plasticizer and the protein. Internal plasticization by covalent bonding surpasses these limitations but requires further research specific for each protein. In addition, synergistic approaches, where different plasticization/cross-linking methods are combined, have shown high potential and emphasize the complexity in the design of the polymer matrix.

The Circular Economy Action Plan, as part of the European Green Deal announced by the European Commission, is highly relevant to the chemical industry in relation to the production of sustainable products. Accordingly, the chemical industry faces the question of how far it can promote its own manufacture of sustainable products. Within this context, this article presents an approach on how to measure innovations in bioeconomy. The methodological framework developed provides the chemical industry with an approach to assess the effectiveness of innovative conversion technologies producing biogenic intermediate products (e.g., bulk chemicals). The innovations within the bioeconomy (TRL > 4; TRL—technology readiness level) are compared in terms of technical, economic, and environmental indicators for the current status, for the medium- and long-term as well as for different production sites. The methodological approach developed here is exemplarily applied, assessing the production of intermediate biogenic products via thermo-chemical conversion of lignocellulosic biomass. The results show the successful applicability of the developed assessment approach as well as significant differences in efficiency, costs, and environmental impact, both from the perspective of time and in spatial terms within the European Union. Thus, the methodological approach developed and presented enables the chemical industry to reduce challenges and to take advantage of the opportunities arising from the transition to a climate-neutral and circular economy.

During the last two decades renewable sources of energy as an environmentally friendly alternative to fossil fuel energy have gained more and more importance within the German electricity system. Their share has increased from less than 4 % to roughly one third of the gross electricity production in the last 25 years. Against this background, the goal of this paper is to present briefly the current status of the use of renewables within the German electricity system, to assess selected developments taking place during this development process as well as to identify given challenges and needs as well as necessary actions to pave the road for a further use of renewable sources of energy within the German electricity provision system. The political driver for the latter is the overarching goal to reduce Greenhouse Gas (GHG) emissions which has been confirmed within the Paris agreement signed by the end of 2015.

Fuel-related measures and modernization of small-scale combustion units has become the focus of attention in the renewable heat generation sector, as a means to promote local biomass utilization and fuel-flexibility while meeting strict environmental legislative requirements. With the aim to mitigate total particulate matter emissions and ash-associated problems characteristic of crop residue combustion, (1) corn cob pellets (with and without kaolin and binder) as well as (2) fuel blends with wood pellets were combusted in a pellet oven under full load. Results show that additivation or fuel blending (e.g., 50 wt. % wood and 50 wt. % corn cob pellets) reduce total particulate and CO-emissions by 48 to 60 wt. % and 64 to 89 wt. %, respectively, in comparison to baseline emissions from non-additivized corn cob pellets. Kaolin prevented sintering of corn cob ash. However, considerable grate ash entrainment was observed. TPM consists of a “primary network”—polyhedral and spherical particles approximately 1 μm in diameter (mainly KCl), and a “secondary network” built on top of the primary network, consisting of square-prism-shaped particles of approximately 200 nm in diameter. KCl and K2SO4 are main compounds in particles from corn cob and wood pellet combustion, respectively. Effective measures demonstrated within this study should be complemented with low-cost coarse ash removal systems.

So far, a lot of efforts have been put in life cycle assessments (LCA) of bioethanol production. There are many works that have assessed bioethanol production in different points of view to illustrate the environmental impacts. This study reviewed former LCA studies on bioethanol produced from various biomass resources by considering the effect of methodological components, technical pathways and feedstock provision on the result of LCA studies. The review evaluated 48 papers published 2002–2021 with a focus on studies that included a complete set of environmental impact categories. However, due to lack of harmony among studies, comparing the LCA results was challenging but the review indicated that the final results of studies are influenced by LCA methodological components, such as system boundary, functional unit, etc. Around 80% of the reviewed papers show the reduction in global warming potential, while contrary results have been found about increasing acidification, eutrophication and photochemical oxidant formation impact categories because of the feedstock provision. Regarding technical aspects, results from the review revealed that most of the studies considered the pre-treatment as a crucial step in bioconversion processes. Despite several LCA studies of bioethanol production, there is still low attention given to uncertainty analysis in the publications.

Biofuels contribute to cover the strongly increasing energy demand within our global transportation system. The current status of biofuel production can be summarized on a world wide scale as follows [1, 2]: Biofuels contribute to cover the strongly increasing energy demand within our global transportation system. The current status of biofuel production can be summarized on a world wide scale as follows [1, 2]:Bioethanol. About 97 Billion l of ethanol (2,218 PJ) were produced in 2015. Roughly 57 % were provided in the US (56.1 Billion l; 1,282 PJ; primarily from corn) and 28 % in Brazil (26.8 Billion l; 614 PJ; mainly from sugar cane). The remaining 15 % were produced in Europe and Asia.Biodiesel / HVO. In 2015, ca. 32 Billion l (1,050 PJ) Biodiesel were sold. Brazil provided ca. 3.5 Billion l (116 PJ) and Germany roughly 3.2 Billion l (105 PJ). The market in North America is dominated by the US with 16 % of the global production (168 PJ). The remaining rest is widely distributed throughout the world and comes from smaller markets like Argentine, Germany, Indonesia and other countries.Other biofuels. To a very minor extend, also bio-methane as well as pure vegetable oil are used. But on a global scale the contribution of these options is negligible.Related to the overall energy demand for transportation purposes this biofuel use of roughly 3.3 EJ (2015) represents a share of less than 3 % [3]. This small share could only be realized over time due to administrative measures implemented by various governments already years ago. There have been manifold communicated reasons to justify these legal measures as well as the resulting financial support from the public purse [4]:Contribution to the reduction of greenhouse gas (GHG) emissions;Protection of scarce and finite fossil fuel resources;Domestic energy provision and thus an increased security of fuel supply;Use of agricultural surplus production and thus avoidance of set aside land;Creation of employment and income in rural areas as well as development of perspectives for farmers;Convenient inclusion into existing technology and market structures of transportation based on fossil fuels;Development and demonstration of technological processes with a high export potential and thus the option of creation of value.These arguments were always questioned critically by parts of the public and especially by environmental NGOs. Among others, the following arguments have been presented:The GHG savings are marginal because the production process for biofuels is quite energy consuming (i.e. no or only negligible net GHG savings);Due to direct and indirect land use change effects (LUC and iLUC) possible GHG reductions are inverted to (significantly) higher GHG emissions compared to fossil fuel use (i.e. biofuels contribute to rain forest clearing);Biofuels contribute to food scarcity and hunger especially in less developed countries due to increasing food prices that are triggered by an increasing demand for land and agricultural products as well certain political instruments that distort the market (e.g. subsidies);Biofuels contribute to monoculture and industrial agriculture as well as to the reduction of biodiversity.Due to this ongoing social debate, significant efforts to minimize negative consequences and to increase acceptance have been made especially within the European Union (EU) in recent years. For example, the following measures have been implemented by the European Commission (EC):Agricultural feedstocks used for biofuel production need to come from sustainable sources; this has to be certified by an independent body. In contrast, no legal sustainability requirements for agricultural feed and food products exist.The subsidies for biofuels are tied up with an assessment of the achieved GHG savings, which are calculated based on a pre-defined mandatory methodology [4]. By decision of the European Parliament, indirect land use change effects are not taken into consideration due to unsolved methodological problems related to their assessment [5].According to the European Commission (EC), additional land demand that results from ambitious biofuel targets can mostly be fulfilled by conversion of land that has been set aside since decades in order to stabilize market prices resulting from overproduction [6].The markets for biofuel feedstock are small compared to the respective markets for food and fodder [7]. Thus, the biofuel markets influence the price creation on the global stock markets only to a minor extend.Nevertheless, serious concerns of a considerable share of the politically active population especially in Western world countries still exist. In order to increase acceptance and to reduce negative consequences of biofuel provision and use, the measures outlined above can only be seen as a (promising) starting point. The overall long term development goal should be that markets for food and feed, markets for biomass as a raw material as well as energy markets support each other by stabilization of the respective biomass prices. Additionally common sustainability standards need to be implemented for these various markets. This is true because typically a large share of biomass is produced regardless of its later use. Market mechanisms “decide” for which purpose (e.g. food, feed, raw material, or biofuel) the biomass available on the market will ultimately be used.Fertile land and thus also biomass produced on this land are a priori a limited resource. Additionally, yields vary due to changing environmental conditions (e.g. drought, flooding, and infestation). Due to these uncertainties, producers are forced to realize a certain over-production exceeding the expected demand to survive economically. Thus – from the view point of the producer – it would be helpful to implement market based measures to level or at least to slow down price variations at the global biomass markets. Energy markets can act as such a stabilizing element because biofuels and conventional fossil fuels can be exchanged completely and immediately. They can help to level out price variations of biomass by taking up agricultural products in case of a global production exceeding the demand from the food and feed market. Vice versa, biofuel production could be reduced in case of low yields and a resulting shortage of biomass to alleviate pressure on the food and feed market. One precondition for creating such a harmonized or stabilized market is that sustainability criteria, which are already mandatorily applied to biomass feedstocks used for biofuel production, are applied to all traded agricultural products regardless of their use. Consequently, such a concept could boost a more sustainable agricultural and forestry primary productionFurthermore, the following targets need to be achieved in the years to come in order to increase competitiveness, reduce negative environmental consequences and to promote acceptance of biofuels:Widening of the biomass resource basis; this includes better crops, the use of organic wastes as well as "new" biomass feedstocks (e.g. algae);Technological advances in biomass production and downstream processing in order to increase efficiencies throughout the overall provision chain;Better combination of biomass production and processing for the various markets to exploit synergy effects and minimize losses (e.g. promotion of the bio-refinery concept);Improved assessment of sustainability criteria throughout the overall provision chain; this includes also aspects like impacts on biodiversity and soil properties, iLUC, child labor etc. Such aspects are essential to cope with an increasing demand for biomass driven by a growing world population, changing consumption patterns as well as an increasing demand for renewable energy provision and industrial purposes. All over, tremendous progress has been made in recent years in increasing sustainability and efficiency of biofuel production. Nevertheless, this process has not come to an end yet.

The production and use of crude oil-based materials, e.g., fossil fuels and bulk chemicals of organic origin, results in an increasing level of CO2 emissions within the atmosphere. One way to reduce such CO2 emissions is to substitute them with synthetic fuels and bulk chemicals. For the production of such CO2 neutral materials, CO2 from various sources can serve as a carbon source. Against this background, this paper analyses and quantifies CO2 emissions released from German industry branches today (2017) and potentially in the future (2050) after a complete defossilization has been achieved. Thus, for the classification of CO2 emissions from the respective industries in 2050, alternative techniques and manufacturing processes are analyzed that might lead to a reduction in energy- and process-related CO2 emissions. Additionally, the individual production sites of the analyzed industries are determined at postcode level and a CO2 potential on NUTS3 level has been developed. Based on this, two scenarios for future CO2 emissions are developed. This shows that, in 2017, the analyzed German industrial sectors emitted almost 143 Mt CO2. By 2050, the overall emissions can be decreased by about 77 Mt to 117 Mt CO2 depending on the implementation level of alternative technologies.

Changes in the mobility patterns have evoked concerns about the future availability of certain raw materials necessary to produce alternative drivetrains and related batteries. The goal of this article is to determine if resource use aspects are adequately reflected within life cycle assessment (LCA) case studies of electric vehicles (EV). Overall, 103 LCA studies on electric vehicles from 2009 to 2018 are evaluated regarding their objective, scope, considered impact categories, and assessment methods—with a focus on resource depletion and criticality. The performed analysis shows that only 24 out of 76 EV LCA and 10 out of 27 battery LCA address the issue of resources. The majority of the studies apply one of these methods: CML-IA, ReCiPe, or Eco-Indicator 99. In most studies, EV show higher results for mineral and metal resource depletion than internal combustion engine vehicles (ICEV). The batteries analysis shows that lithium, manganese, copper, and nickel are responsible for the highest burdens. Only few publications approach resource criticality. Although this topic is a serious concern for future mobility, it is currently not comprehensively and consistently considered within LCA studies of electric vehicles. Criticality should be included in the analyses in order to derive results on the potential risks associated with certain resources.