• Energy Research

The supporting information of the journal article "Evaluation of sugar feedstocks for bio-based chemicals: A consequential, regionalized life cycle assessment" from Fabbri et al. (2022) includes one file with the following content: S1 Details of consequential modelling: feedstock S1.1 Identification type of changes (demand or supply) S1.2 Identification of constrains in the market S1.3 Identification of product substitutions S1.4 Identification of affected production technology S1.5 Identification of marginal crop and marginal supplier S2 Details of consequential modelling: by-products S3 Model parameters and unit processes S3.1 Sugar beet S3.2 Sugar cane S3.3 Wheat S3.4 Maize S3.5 Wood S3.6 Residual woodchips and sawdust S4 Review of land use change accounting methods S4.1 Direct land use change (dLUC) S4.2. Indirect land use change (iLUC) S5 Additional results S5.1 Influence of spatial differentiation in LCIA S5.2 Influence of indirect land use change (iLUC) S6 References This work was funded by the Innovation Fund Denmark under the Grand Solutions instrument; project ReMEG "Renewable Mono Ethylene Glycol for PET Plastic".

The merits of temporary carbon storage are often debated for bio-based and biodegradable plastics. We employed life cycle assessment (LCA) to assess environmental performance of polyhydroxyalkanoate (PHA)-based plastics, considering multiple climate tipping as a new life cycle impact category. It accounts for the contribution of GHG emissions to trigger climate tipping points in the Earth system, considering in total 13 tipping elements that could pass a tipping point with increasing warming. The PHA was either laminated with poly(lactic acid), or metallized with aluminum or aluminum oxides to lower permeability of the resulting plastics toward oxygen, water vapor and aromas. The assessments were made accounting for potential differences in kinetics of evolution of greenhouse gases (CO2, CH4) from bioplastic degradation in the end-of-life. Results show that: (1) PHA films with high biodegradability perform best in relation to the climate tipping, but are not necessarily the best in relation to radiative forcing increase or global temperature change; (2) sugar beet molasses used as feedstock is an environmental hot spot, contributing significantly to a wide range of environmental problems; (3) increasing PHA production scale from pilot to full commercial scale increases environmental impacts, mainly due to decreasing PHA yield; and (4) further process optimization is necessary for the PHA-based plastics to become attractive alternatives to fossil-based plastics. Our study suggests that multiple climate tipping is a relevant impact category for LCA of biodegradable bioplastics.

De nombreuses tentatives récentes de commercialisation de l'acide biosuccinique (bio-SA) ont échoué après un début florissant. En outre, la performance environnementale améliorée des processus de production bio-SA par rapport aux SA à base de pétrole est encore incertaine. Dans cette étude, une analyse technico-économique a été menée en comparant quatre processus de fabrication bio-SA en termes de valeur actuelle nette et de prix de vente minimum. Deux des processus simulés sont basés sur des brevets publiés par des sociétés de fabrication de bio-SA (I) Roquette/DSM (Reverdia) et (II) DNP Green Technology/ARD (BioAmber). Un troisième processus est basé sur un brevet de la Michigan State University (III) et un quatrième processus est conceptuel (IV). Il a été démontré que le processus conceptuel IV avait des coûts d'investissement inférieurs de <50 % et des coûts de fabrication inférieurs de 40 à 55 % aux autres processus. Avec un prix de vente minimum de 1,4 USD kg−1, le processus IV serait moins cher que l'acide succinique à base de pétrole (∼2,0 USD kg−1). Le processus basé sur Reverdia peut également être compétitif, tandis que le processus III et en particulier le processus II basé sur BioAmber ne sont pas rentables. Les colonnes d'échange d'ions, la nanofiltration et les membranes d'échange d'anions se sont révélées être des technologies clés pour réduire les coûts de fabrication du bio-SA. La fermentation bio-SA continue avec extraction in situ peut changer le marché bio-SA, mais l'évaluation de la durabilité environnementale ne révèle que des différences marginales par rapport à l'AS à base de pétrole. La « fermentation aérobie » à faible pH est susceptible d'être une stratégie plus durable par rapport à la « fermentation aérobie » à pH neutre. Muchos intentos recientes de comercializar ácido biosuccínico (bio-SA) terminaron sin éxito después de un momento de florecimiento inicial. Además, el rendimiento ambiental mejorado de los procesos de producción de bio-SA en comparación con SA a base de petróleo aún es incierto. En este estudio se realizó un análisis tecnoeconómico comparando cuatro procesos de fabricación de bio-SA en términos de valor actual neto y precio mínimo de venta. Dos de los procesos simulados se basan en patentes emitidas por las empresas de fabricación bio-SA (I) Roquette/DSM (Reverdia) y (II) DNP Green Technology/ARD (BioAmber). Un tercer proceso se basa en una patente de la Universidad Estatal de Michigan (III) y un cuarto proceso es conceptual (IV). Se demostró que el proceso conceptual IV tiene <50% menos costes de capital y ~40 a 55% menos costes de fabricación que los otros procesos. Con un precio de venta mínimo de 1,4 USD kg-1, el proceso IV sería más barato que el ácido succínico a base de petróleo (~2,0 USD kg-1). El proceso basado en Reverdia también puede ser competitivo, mientras que el proceso III y particularmente el proceso II basado en BioAmber no son rentables. Se ha demostrado que las columnas de intercambio iónico, la nanofiltración y las membranas de intercambio aniónico son tecnologías clave para reducir los costes de fabricación de bio-SA. La fermentación continua de bio-SA con extracción in situ puede cambiar el mercado de bio-SA, pero la evaluación de sostenibilidad ambiental revela solo diferencias marginales en comparación con SA a base de petróleo. Es probable que la "fermentación aeróbica" de pH bajo sea una estrategia más sostenible en comparación con la "fermentación aeróbica" de pH neutro. Many recent attempts to commercialize bio-succinic acid (bio-SA) ended to be unsuccessful after a start flourishing moment. Furthermore, the improved environmental performance of bio-SA production processes compared to petroleum-based SA is still uncertain. In this study a techno-economic analysis was conducted comparing four bio-SA manufacturing processes in terms of net present value and minimum selling price. Two of the simulated processes are based on patents released by bio-SA manufacturing companies (I) Roquette/DSM (Reverdia) and (II) DNP Green Technology/ARD (BioAmber). A third process is based on a Michigan State University patent (III) and a fourth process is conceptual (IV). The conceptual process IV was demonstrated to have <50% lower capital costs and ∼40 to 55% lower manufacturing costs than the other processes. With a minimum selling price of 1.4 USD kg−1, process IV would be cheaper than petroleum based succinic acid (∼2.0 USD kg−1). The Reverdia-based process can also be competitive, while process III and particularly the BioAmber-based process II are not profitable. Ion-exchange columns, nanofiltration and anion exchange membranes are shown to be key technologies for lowering bio-SA manufacturing costs. Continuous bio-SA fermentation with in situ-like extraction can change the bio-SA market, but the environmental sustainability assessment reveals only marginal differences compared with petroleum-based SA. Low pH "aerobic fermentation" is likely to be a more sustainable strategy compared to neutral pH "aerobic fermentation". انتهت العديد من المحاولات الأخيرة لتسويق حمض السكسينيك الحيوي (BIO - SA) بالفشل بعد لحظة ازدهار. علاوة على ذلك، لا يزال الأداء البيئي المحسن لعمليات إنتاج المأوى الحيوي مقارنة بالمأوى القائم على النفط غير مؤكد. في هذه الدراسة، تم إجراء تحليل تقني اقتصادي يقارن بين أربع عمليات تصنيع بيولوجية من حيث صافي القيمة الحالية والحد الأدنى لسعر البيع. تعتمد اثنتان من عمليات المحاكاة على براءات الاختراع الصادرة عن شركات التصنيع BIO - SA (I) Roquette/DSM (Reverdia) و (II) DNP Green Technology/ARD (BioAmber). تعتمد العملية الثالثة على براءة اختراع جامعة ولاية ميشيغان (III) والعملية الرابعة هي عملية مفاهيمية (IV). وقد ثبت أن العملية المفاهيمية الرابعة لديها تكاليف رأسمالية أقل بنسبة <50 ٪ وتكاليف تصنيع أقل بنسبة 40 إلى 55 ٪ من العمليات الأخرى. مع سعر بيع لا يقل عن 1.4 كجم−1 دولار أمريكي، ستكون العملية الرابعة أرخص من حمض السكسينيك القائم على البترول (2.0 كجم−1 دولار أمريكي). يمكن أن تكون العملية القائمة على Reverdia تنافسية أيضًا، في حين أن العملية الثالثة وخاصة العملية الثانية القائمة على BioAmber ليست مربحة. تُظهر أعمدة التبادل الأيوني والترشيح النانوي وأغشية التبادل الأنيوني أنها تقنيات رئيسية لخفض تكاليف التصنيع الحيوي. يمكن أن يؤدي التخمير المستمر للسلامة الأحيائية مع الاستخراج الشبيه بالموقع إلى تغيير سوق السلامة الأحيائية، لكن تقييم الاستدامة البيئية يكشف عن اختلافات هامشية فقط مقارنة بالسلامة الأحيائية القائمة على النفط. من المرجح أن يكون "التخمير الهوائي" المنخفض لدرجة الحموضة استراتيجية أكثر استدامة مقارنة بـ "التخمير الهوائي" المحايد لدرجة الحموضة.

AbstractFermentable sugars are an attractive feedstock for the production of bio‐based chemicals. However, little is known about the environmental performance of sugar feedstocks when demand for sugars increases, and when local conditions and sensitivities of receiving ecosystems are taken into account. Production of monosaccharides from various first‐ and second‐generation feedstocks (sugar beet, sugar cane, wheat, maize, wood, residual woodchips, and sawdust) in different geographic locations was assessed and compared as feedstock for monoethylene glycol (MEG) using consequential, regionalized life cycle assessment. Sugar cane grown in Thailand performed best in all three areas of protection, that is, for life cycle impacts on human health, ecosystem quality, and resources (respectively, equal to −7.6 × 10−5 disability‐adjusted life years, −1.2 × 10−8 species‐years and −0.046 US dollars per amount of feedstock needed to produce 1 kg of MEG). This was mainly due to benefits from by‐products—incineration of sugar cane bagasse generating electricity and use of sugar cane molasses for the production of bioethanol. The wood‐based feedstocks and maize performed worse than sugar cane and sugar beet, but their evaluation did not consider that sugar extraction technology from lignocellulose is immature, while identification of marginal suppliers of the marginal crop is particularly uncertain for maize. Wheat grown in Russia performed the worst mainly due to low agricultural yields (with impacts equal to 8.9 × 10−5 disability‐adjusted life years, 6.9 × 10−7 species‐years, and 1.8 US dollars per amount of feedstock required to produce 1 kg of bio‐based MEG). Our results suggest that selection of sugar feedstocks for bio‐based chemicals should focus on (i) the intended use of by‐products and functions they replace and (ii) consideration of geographic differences in parameters that influence life cycle inventories, while spatial differentiation in the life cycle impact assessment was less influential.

Mounting evidence indicates that climate tipping points can have large, potentially irreversible, impacts on the earth system and human societies. Yet, climate change metrics applied in current sustainability assessment methods generally do not consider these tipping points, with the use of arbitrarily determined time horizons and assumptions that the climate impact of a product or service is independent of emission timing. Here, we propose a new method for calculating climate tipping characterization factors for greenhouse gases (carbon dioxide, methane, and nitrous oxide) at midpoint. It covers 13 projected tipping points, incorporates the effect that the crossing of a given tipping point has on accelerating the crossing of other tipping points, and addresses uncertainties in the temperature thresholds that trigger the tipping points. To demonstrate the added value of the new metric, we apply it to emissions stemming from end-of-life of plastic polymers and compare them with commonly used metrics. This highlights the need to consider climate tipping in sustainability assessment of products and services.