Human health impacts of aviation biofuel production: Exploring the application of different life cycle impact assessment (LCIA) methods for biofuel supply chains

The life cycle human health (HH) impacts related to aviation biofuels have been understood in a limited way. Life cycle impact assessment (LCIA) methods for assessing HH are often associated with a high level of uncertainty and a low level of consensus. As a result, it remains challenging to perform a robust assessment of HH impacts with a suitable LCIA method. This study aims to systematically compare six commonly used LCIA methods for quantifying HH impacts, in order to empirically understand the potential impacts of aviation biofuel production on HH and how the results are affected by the choice of methods. Three aviation biofuel production pathways based on different feedstocks (sugarcane, eucalyptus, and macauba) were analyzed and compared to fossil aviation biofuels, on the basis of a functional unit of 1 MJ aviation fuel. The majority of the LCIA methods suggest that, in respect to midpoint impacts, macauba-based biofuel is associated with the lowest impacts and eucalyptus-based biofuel the highest; whereas at endpoint level, the results are more scattered. The LCIA methods agree that biomass conversion into aviation biofuel, H2 production, and feedstock cultivation are major contributors to life cycle HH impacts. Additionally, we provide a guideline for determining an appropriate method for assessing HH impacts.BT/Biotechnology and Societ

Societal and Ethical Issues in Industrial Biotechnology

In this chapter we aim to give an overview of the main societal and ethical issues that are currently voiced around industrial biotechnology. We will illustrate this with some recent cases, such as the development of synthetic artemisinin, synthetic vanillin and vegetable oil produced by engineered algae. We show that current societal and ethical issues in industrial biotechnology centre on the following five themes: sustainability, naturalness, innovation trajectories, risk management and economic justice. In each of these themes, clashing public opinions fuel the public debate on the acceptability of new industrial biotechnology. In some cases this has led to the failure of otherwise promising innovations. In the last part, we provide suggestions on how to deal with these ethical and societal aspects based on the approach of Responsible Research and Innovation (RRI).BT/Biotechnology and Societ

Analysis of biomass hydrothermal liquefaction and biocrude-oil upgrading for renewable jet fuel production: The impact of reaction conditions on production costs and GHG emissions performance

This paper shows a detailed analysis of a biomass HTL process by considering changes in three main reaction variables (i.e. catalysts (water, Na2CO3(aq.), and Fe(aq.)), temperature (280–340 °C), and catalysts/biomass mass ratio (0–0.33 kg catalysts/kg biomass)), and by assessing their influence on the techno-economic and GHG emissions performance. This analysis is based on Aspen Plus® simulations, process economics and life-cycle GHG assessment on SimaPro (using Ecoinvent 2.2). Results showed that the lowest production cost for biocrude oil is achieved when HTL is performed at 340 °C with Fe as catalyst (450 €/tbiocrude-oil or 13.6 €/GJbiocrude-oil). At these conditions, the biocrude oil produced has an oxygen content of 16.6 wt% and a LHV of 33.1 MJ/kgbiocrude-oil. When the hydrotreatment and hydrogen generation units are included, the total production costs was 1040 €/tupgraded-oil or 0.8 €/Lupgraded-oil. After fractionation, the estimated production cost was 1086 €/tbiojet-fuel or 25.1 €/GJbiojet-fuel. This value is twice the commercial price of fossil jet fuel. However, the allocated life cycle GHG emissions for renewable jet fuel were estimated at 13.1 kgCO2-eq./GJbiojet-fuel, representing only 15% the GHG emission of fossil jet fuel and therefore, indicating a significant potential on GHG emission reduction.BT/Biotechnology and Societ

Mass and heat integration in ethanol production mills for enhanced process efficiency and exergy-based renewability performance

This paper presents the process design and assessment of a sugarcane-based ethanol production system that combines the usage of both mass and heat integration (pinch analysis) strategies to enhance the process efficiency and renewability performance. Three configurations were analyzed: (i) Base case: traditional ethanol production (1G); (ii) mass-integrated (1G2G); and (iii) mass and heat-integrated system (1G2G-HI). The overall assessment of these systems was based on complementary approaches such as mass and mass-heat integration, energy and exergy analysis, exergy-based greenhouse gas (GHG) emissions, and renewability exergy criteria. The performances of the three cases were assessed through five key performance indicators (KIPs) divided into two groups: one is related to process performance, namely, energy efficiency, exergy efficiency, and average unitary exergy cost (AUEC), and the other one is associated to environmental performance i.e., exergy-based CO2-equation emissions and renewability exergy index. Results showed a higher exergy efficiency of 50% and the lowest AUEC of all the systems (1.61 kJ/kJ) for 1G2G-HI. Furthermore, the destroyed exergy in 1G2G-HI was lower by 7% and 9% in comparison to the 1G and 1G2G cases, respectively. Regarding the exergy-based GHG emissions and renewability performance (λindex), the 1G2G-HI case presented the lowest impacts in terms of the CO2-equivalent emissions (94.10 gCO2-eq/MJ products), while λindex was found to be environmentally unfavorable (λ = 0.77). However, λindex became favorable (λ > 1) when the useful exergy of the byproducts was considered.BT/Biotechnology and Societ

Logistics and Costs of Agricultural Residues for Cellulosic Ethanol Production

There is global pressure to make advanced biofuels profitable. For cellulosic ethanol, three aspects remain as bottlenecks: collection of feedstocks, pretreatment methods, and enzyme production. In this paper, the first aspect is investigated, by addressing the main challenges for the logistics of agricultural residues. A logistic supply chain of corn stover collection and utilization for cellulosic ethanol production in Mexico is proposed, and a cost structure is designed for its estimation. By applying a value chain methodology, seven links and a set of three minimum selling prices (MSPs) of agricultural residues were determined. Furthermore, the harvest index (HI), crop residue index (CRI), nutrient substitution by extraction of agricultural residues, and harvest costs of corn stover were also calculated for a case study. The main results were a HI of 0.45, a CRI of 1.21, and nutrient substitution potential of 7 kg N, 2.2 kg P 2O 5, and 12.2 kg K 2O per ton of corn stover. The set of the three estimated MSPs for corn stover was: $28.49 USD/ton (for delivery to the biorefinery’s gate),$31.15 USD/ton (for delivery and storage), and $48.14 USD/ton (for delivery, storage, and nutrient replenishment). Given the impact of the feedstock cost on the profitability of cellulosic ethanol, knowing details of the logistical information and its costs is critical to advancing the field of biofuels in Mexico. We also found that only 20% of farmers currently sell their residues; however, 65% of farmers would be willing to do so, a significant percentage for cellulosic ethanol production. BT/Biotechnology and Societ

Integrating Value Considerations in the Decision Making for the Design of Biorefineries

Biobased production has been promoted as a sustainable alternative to fossil resources. However, controversies over its impact on sustainability highlight societal concerns, value tensions and uncertainties that have not been taken into account during its development. In this work, the consideration of stakeholders’ values in a biorefinery design project is investigated. Value sensitive design (VSD) is a promising approach to the design of technologies with consideration of stakeholders’ values, however, it is not directly applicable for complex systems like biorefineries. Therefore, some elements of VSD, such as the identification of relevant values and their connection to a technology’s features, are brought into biorefinery design practice. Midstream modulation (MM), an approach to promoting the consideration of societal aspects during research and development activities, is applied to promote reflection and value considerations during the design decision making. As result, it is shown that MM interventions during the design process led to new design alternatives in support of stakeholders' values, and allowed to recognize and respond to emerging value tensions within the scope of the project. In this way, the present work shows a novel approach for the technical investigation of VSD, especially for biorefineries. Also, based on this work it is argued that not only reflection, but also flexibility and openness are important for the application of VSD in the context of biorefinery design.BT/Biotechnology and Societ

Socioeconomic effects of aviation biofuel production in Brazil: A scenarios-based Input-Output analysis

Derived from renewable feedstocks, aviation biofuel is generally perceived as inherently sustainable. However, its production involves a wide range of sectors and interacts with different actors in society. It is therefore important to understand and evaluate not only the environmental impacts of that process, but also its socioeconomic effects. At present, empirical studies assessing socioeconomic aspects of aviation biofuel are rare in scientific literature. The aim of this study, therefore, is to assess key effects of aviation biofuel production on employment, GDP, and trade balance. A scenarios-based Input-Output (IO) analysis was used to evaluate these socioeconomic effects, taking Brazilian aviation biofuel production to 2050 as an example. To address the uncertainty of IO analysis, we have proposed a stochastic simulation approach for the technical coefficients in the IO model. Four distinct scenarios were developed. In each, three potential combinations of technologies and feedstocks for producing aviation biofuel were evaluated: sugarcane via alcohol to jet (ATJ), macauba via hydro-processed esters and fatty acids (HEFA), and eucalyptus via Fischer-Tropsch (FT). Among other things, we found that the production of aviation biofuel would create around 12,000–65,000 jobs, while contributing US$200-1100 million to Brazil's GDP under different scenarios with different supply chains. The socioeconomic effects calculated deterministically were generally higher than the stochastic outcomes, which can be explained by factors such as technological learning and economic growth. Aviation biofuel production showed large positive net socioeconomic effects on employment and GDP, although some of the fossil sectors would be negatively affected. Overall, the macauba-HEFA chain (with the highest effects on employment and GDP, and the lowest effects on imports) seemed to be the most favorable of the scenarios studied, despite the relatively high level of uncertainty associated with it.Accepted Author ManuscriptBT/Biotechnology and Societ

Decarbonizing ethanol production via gas fermentation: Impact of the CO/H₂/CO₂ mix source on greenhouse gas emissions and production costs

This study explores key success factors for ethanol production via fermentation of gas streams, by assessing the effects of eight process variables driving the fermentation performance on the production costs and greenhouse gas emissions. Three fermentation feedstocks are assessed: off-gases from the steel industry, lignocellulosic biomass-derived syngas and a mixture of H2 and CO2. The analysis is done through a sequence of (i) sensitivity analyses based on stochastic simulations and (ii) multi-objective optimizations. In economic terms, the use of steel off-gas leads to the best performance and the highest robustness to low mass transfer coefficients, low microbial tolerance to ethanol, acetic-acid co-production and to dilution of the gas feed with CO2, due to the relatively high temperature at which the gas feedstock is available. The ethanol produced from the three feedstocks lead to lower greenhouse gas emissions than fossil-based gasoline and compete with first and second generation ethanol.BT/Biotechnology and SocietyBT/Bioprocess Engineerin

A systematic approach for the processing of experimental data from anaerobic syngas fermentations

This study describes a methodological framework designed for the systematic processing of experimental syngas fermentation data for its use by metabolic models at pseudo-steady state and at transient state. The developed approach allows the use of not only own experimental data but also from experiments reported in literature which employ a wide range of gas feed compositions (from pure CO to a mixture between H2 and CO2), different pH values, two different bacterial strains and bioreactor configurations (stirred tanks and bubble columns). The developed data processing framework includes i) the smoothing of time-dependent concentrations data (using moving averages and statistical methods that reduce the relevance of outliers), ii) the reconciliation of net conversion rates such that mass balances are satisfied from a black-box perspective (using minimizations), and iii) the estimation of dissolved concentrations of the syngas components (CO, H2 and CO2) in the fermentation broth (using mass transfer models). Special care has been given such that the framework allows the estimation of missing or unreported net conversion data and metabolite concentrations at the intra or extracellular spaces (considering that there is availability of at least two replicate experiments) through the use of approximative kinetic equations.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.BT/Bioprocess EngineeringBT/Biotechnology and Societ

Exploring resource recovery potentials for the aerobic granular sludge process by mass and energy balances - energy, biopolymer and phosphorous recovery from municipal wastewater

Municipal wastewater cannot any longer be perceived as a waste stream because it contains water, energy, fertilizer and other products that can be recovered with innovative technologies in so called ‘water resource factories’. Therefore a paradigm shift has been proclaimed to design water resource factories in the future that feed into a circular economy. The rapid development of new resource recovery technologies requires a solid analysis prior to their integration into treatment processes to understand more about their potential to contribute to more circular urban water management practices. Mass and energy balances are an excellent method to model resource recovery potentials of innovative processes at an early design stage because they allow quantifying recoverable resources as well as trade-offs between possible recovery technology choices. We modelled a real wastewater treatment plant which uses aerobic granular sludge treatment and is currently operated with no on-site resource recovery. Then, 5 different possible process designs that would recover chemical oxygen demand (COD) as energy and/or extracellular polymeric substances (EPS), and phosphorous (P) as struvite have been modelled. The integration of anaerobic digestion for subsequent electricity and heat generation from methane provides the possibility to recover on-site a rather small fraction of influent-COD as energy. But if this is combined with chemically enhanced primary treatment (CEPT), almost one third of the influent-COD may be recovered. Simultaneous energy and EPS recovery may lead to trade-offs as CEPT integration for maximum energy recovery may halve the EPS recovery potential but would increase the overall influent-COD recovery rate. Struvite fertilizer recovery integration may only recover a small fraction of influent-P and is therefore questionable when other P recovery options are possible that aim for higher recovery rates. The fertilizer recovery potential may be significantly decreased by EPS recovery since the latter contain P. This study helps to understand how aerobic granular sludge based treatment processes can be designed as water resource factories. Mass and energy balances can be conducted at a very early process design stage and results may be used to identify promising process designs for subsequent more in depth techno-economic or environmental impact assessments.BT/Biotechnology and SocietyBT/Environmental Biotechnolog