Kraft lignin as a bio-based ingredient for Dutch asphalts: An attributional LCA

Kraft lignin fast (catalytic) pyrolysis for the production of high value-added chemicals (HVACs): A techno-economic screening of valorization pathways

This paper presents a techno-economic analysis (TEA) of six (6) scenarios of the kraft lignin catalytic (CFP) and thermal (TFP) fast pyrolysis towards the production of high value-added chemicals (HVACs) and electric energy, based on experimental data from our previous work. ASPEN PLUS was used to simulate the proposed plants/scenarios and retrofitted custom-based economic models that were developed in Microsoft EXCEL. The results showed that scenarios 1 and 2 in which the produced bio-oil is used as fuel for electricity production are the most cost-deficient. On the other hand, scenarios 3 and 6 that utilize the light bio-oil fraction to recover distinct HVACs, along with the use of heavier fractions for electricity production, have showed a significant investment viability, since profitability measures are high. Furthermore, scenarios 4 and 5 that refer to the recovery of mixtures (fractions) of HVACs, are considered an intermediate investment option due to the reduced cost of separation. All the proposed scenarios have a substantial total capital investment (TCI) which ranges from 135 MM€ (scenario 4) to 380 MM€ (scenario 6) with a Lang factor of 6.08, which shows that the CAPEX results are within reason. As far as the comparison of lignin CFP and TFP goes, it is shown that lignin CFP leads to the production of aromatic and phenolic monomers which have a substantial market value, while TFP can lead to important value-added chemicals with a lower OPEX than CFP. A target of return of investment (ROI) of 32% has been set for the selling prices of the HVACs. In summary, this study aims at listing and assessing a set of economic indicators for industrial size plants that use lignin CFP and TFP towards the production of high value-added chemicals and energy production and to provide simulation data for comparative analysis of three bio-oil separation methods, i.e. distillation, liquid-liquid extraction and moving bed chromatography.

Synergies and gaps between circularity assessment and Life Cycle Assessment (LCA)

This article evaluates the synergies between circularity assessment and Life Cycle Assessment (LCA) by investigating their alignments, misalignments, and challenges in addressing sustainability. The analysis emphasizes the significance of a multi-level approach, positioning these methods at various levels, including philosophy, strategy, assessment, and communication. The findings demonstrate that both LCA and circularity assessment can serve as sustainability assessment methods for circularity strategies, despite existing gaps. However, neither approach can provide a complete picture of a system's environmental performance on its own. Data availability, diverse assumptions, spotlights and shadows (highlighted and neglected elements), multiple life cycles, products, functions, strategies, and as well as temporal aspects are identified as the main challenges in addressing sustainability. This article provides recommendations based on the lessons learned from each approach, suggesting the integration of their strengths and addressing challenges to achieve a comprehensive understanding of environmental sustainability and make informed decisions for a circular and sustainable future. These recommendations include using function-based models and the principles of prospective and dynamic LCAs for the development of future circularity assessments. Additionally, circularity assessment can be used to establish LCA models, aiding in identifying hotspots during the goal and scope definition, and determining allocation and weighting factors in both Life Cycle Inventory (LCI) and Life Cycle Impact Assessment (LCIA).

Performance of bio-asphalts: state of the art review

The global population spike, rise in industrialization, and highway infrastructure development induce focus on sustainable development. The ever-increasing consumption of non-renewable crude oil and asphalt levies a heavy toll on economic welfare of future generations. This enormous demand of asphalt is due to its wide applicability in flexible pavements. Therefore, the construction industry is exploring the partial substitution of renewable materials in asphalt with a focus on economical, social, and environmental benefits. The current decade has seen a rampant rise of bio-asphalt as an alternative to asphalt. Hence, it is imperative to explore the performance of bio-asphalt for its sustainable applicability. This review comprehensively summarizes the performance of bio-asphalt obtained from various biomass sources. It deals with elemental composition of bio-oil, preparation procedure, rheological performance, mixture performance, and aging mechanism of bio-asphalt along with modification required to improve the performance. The environmental impacts and field application of the bio-asphalts are also discussed.

A framework for determining the life cycle GHG emissions of fossil marine fuels in countries reliant on imported energy through maritime transportation: A case study of South Korea

This research was motivated to address limitations in the current lifecycle assessment frameworks with the absence of proper guidelines for developing default lifecycle values of energies in consideration of supply chain activities and maritime transportation. Given this, it aims to evaluate the level of life cycle GHG emissions of heavy fuel oil, LNG, LPG and methanol as marine fuels produced and supplied in energy import-dependent countries, using South Korea as a case study. The analysis clearly shows that the impact of international shipping on Well-to-Tank (WtT) GHG emissions for energy carriers would be subject to several factors: propulsion system types, the quantify of energy transported, and the routes and distances of voyages. For instance, transportation emissions from LNG carriers for LNG fuel vary significantly depending on the country of import, ranging from 2.26 g CO2 eq./MJ (representing 12.2 % of Well-to-Tank (WtT) emissions for Malaysia) to 5.97 g CO2 eq./MJ (representing 33.3 % of WtT emissions for Qatar). As a preliminary study, an enhancement on the quality of the input/inventory data is imperative for obtaining a reliability of results. Nevertheless, the comparative analysis of different fuels and life stages provides valuable insights for stakeholders to develop effective policies and energy refueling plans for reducing life cycle GHG emissions from marine fuels. These findings could also enhance the current regulatory framework and provide meaningful lifecycle carbon footprints of marine fuels for energy importing countries. The study results also strongly suggest that default values of GHG emission for different countries relying on energy imports via international maritime transport should be further developed in consideration of the impact of regional differences, such as distance, from the importing country for successful arrival of LCA application on marine industry.

Consequential life cycle assessment of kraft lignin recovery with chemical recycling

The recovery of kraft lignin from black liquor allows an increasing of the pulp production of a kraft mill (marginal tonnage) and at the same time provide a valuable material that can be used as energy or chemical feedstock. However, because lignin precipitation is an energy- and material-consuming process, the environmental consequences from a life cycle perspective are under discourse. The aim of this study is to investigate, through the application of consequential life cycle assessment, the potential environmental benefits of kraft lignin recovery and its subsequent use as an energy or chemical feedstock. A newly developed chemical recovery strategy was assessed. The results revealed how the use of lignin as energy feedstock is not environmentally advantageous compared to producing energy directly from the pulp mill's recovery boiler. However, the best results were observed when lignin was used as a chemical feedstock in four applications to replace bitumen, carbon black, phenol, and bisphenol-A.

Getting Value from Pulp and Paper Industry Wastes: On the Way to Sustainability and Circular Economy

The pulp and paper industry is recognized as a well-established sector, which throughout its process, generates a vast amount of waste streams with the capacity to be valorized. Typically, these residues are burned for energy purposes, but their use as substrates for biological processes could be a more efficient and sustainable alternative. With this aim, it is essential to identify and characterize each type of waste to determine its biotechnological potential. In this context, this research highlights possible alternatives with lower environmental impact and higher revenues. The bio-based pathway should be a promising alternative for the valorization of pulp and paper industry wastes, in particular for bioproduct production such as bioethanol, polyhydroxyalkanoates (PHA), and biogas. This article focuses on state of the art regarding the identification and characterization of these wastes, their main applied deconstruction technologies and the valorization pathways reported for the production of the abovementioned bioproducts.

Furanic Humins from Biorefinery as Biobased Binder for Bitumen

To decrease the environmental impact of bitumen, more sustainable binders should be proposed. This study emphasizes how industrial humins co-produced during the biorefining of carbohydrates can be employed as a macromolecular binder for bitumen. Humins are heterogeneous polyfuranic compounds, and they were mixed at 50 wt% with bitumen. When the non-water-soluble fractions of humins were employed (Hns), no variation of the chemical structure was observed in FTIR spectra after the mixing. The DSC investigations showed that the crystallization of aromatic fractions in bitumen shifted to higher temperature for humins’ modified bitumen. The thermogravimetric data highlighted that the presence of humins or Hns in bitumen can lead to mass loss below 200 °C. The rheological investigations highlighted some key advantages of using humins or Hns with bitumen. At high temperatures, the storage modulus of the modified bitumen is increased and shows lower susceptibility to variations in frequency. At low temperatures, the phase angle of Hns-modified bitumen is lower than that of bitumen, suggesting less temperature susceptibility as a consequence of a cross-linked network formation.