Comparative economic and environmental assessment of four beech wood based biorefinery concepts

Correlation between Lignin-Carbohydrate Complex Content in Grass Lignins and Phenolic Aldehyde Production by Rapid Spray Ozonolysis

We provide strong evidence that the amounts of phenolic aldehydes (vanillin and p-hydroxybenzaldehyde, pHB) selectively released during rapid ozonolysis of grass lignins are correlated with the unsubstituted aryl carbons of lignin-carbohydrate complexes present in these lignins. In the case of acetosolv lignin from corn stover, we observed a steady yield of vanillin and pHB (cumulatively ∼5 wt % of the initial lignin). We demonstrate the continuous ozonolysis of the lignin in a spray reactor at ambient temperature and pressure. In sharp contrast, similar ozonolysis of acetosolv lignin from corn cobs resulted in a twofold increase in the combined yield (∼10 wt %) of vanillin and pHB. Structural analysis with ¹H-¹³C heteronuclear single quantum coherence (HSQC) nuclear magnetic resonance revealed that signals assigned to unsubstituted aryl carbons of lignin-carbohydrate complexes are quantitatively correlated to phenolic aldehyde production from spray ozonolysis. The ratios of the integrated peak volumes corresponding to coumarates and ferulates in the HSQC spectra of cob and corn stover lignins (SLs) are 2.4 and 2.0, respectively. These ratios are nearly identical to the observed 2.3-fold increase in pHB and 1.8-fold increase in vanillin production rates from corn cob lignin compared to corn SL. Considering that the annual U.S. lignin capacity from these grass lignin sources is ∼60 million MT, the value creation potential from these flavoring agents is conservatively ∼$50 million annually from just 10% of the lignin. These new insights into structure/product correlation and spray reactor characteristics provide rational guidance for developing viable technologies to valorize grass lignins.

What Drives a Future German Bioeconomy? A Narrative and STEEPLE Analysis for Explorative Characterisation of Scenario Drivers

A future bioeconomy pursues the transformation of the resource base from fossil to renewable materials in an effort to develop a holistic, sustainable production and provision system. While the significance of this change in the German context is not yet entirely explored, scenarios analysing possible pathways could support the understanding of these changes and their systemic implications. Bioeconomy in detail depends on respective framework conditions, such as the availability of biomass or technological research priorities. Thus, for scenario creation, transferable methods for flexible input settings are needed. Addressing this issue, the study identifies relevant bioeconomy scenario drivers. With the theoretical approach of narrative analysis, 92 statements of the German National Bioeconomy Strategy 2020 have been evaluated and 21 international studies in a STEEPLE framework were assessed. For a future German bioeconomy 19 important drivers could be determined and specific aspects of the resource base, production processes and products as well as overarching issues were exploratively characterised on a quantitative and qualitative basis. The developed method demonstrate an approach for a transparent scenario driver identification that is applicable to other strategy papers. The results illustrate a possible future German bioeconomy that is resource- and technology-driven by following a value-based objective, and which is supplied by biogenic residue and side product feedstocks. As such, the bioeconomy scenario drivers can be used as a starting point for future research like scenario development or modelling of a future German bioeconomy.

A critical review of life cycle assessment studies of woody biomass conversion to sugars

Woody biomass could potentially become a viable raw material for the future sustainable chemical industry. For this, a suitable regulatory framework must exist, that would create favourable economic conditions for wood biorefineries. Such policies must be developed on the basis of scientific evidence-in this case, data supporting the environmental advantages of the bio-based feedstocks to the chemical industry. The most suitable methodology for comprehensive evaluation of environmental performance of technologies is life cycle assessment (LCA). In this review, the available LCA studies of woody biomass fractionation and conversion to bulk chemical feedstocks are critically evaluated. It has been revealed that the majority of the openly available studies do not contain transparent inventory data and, therefore, cannot be verified or re-used; studies containing inventory data are reported in this review. The lack of inventory data also prevents comparison between studies of the same processes performed with different evaluation methods or using different system boundaries. Recommendations are proposed on how to overcome issues of commercial data sensitivity by using black-box modelling when reporting environmental information. From several comparable LCA studies, it has been concluded that today the most environmentally favourable technology for wood biomass fractionation is organosolv. This article is part of the theme issue 'Bio-derived and bioinspired sustainable advanced materials for emerging technologies (part 1)'.

Optimal timing of multiple investment decisions in a wood value chain: A real options approach

A new reductive catalytic fractionation biorefinery process (RCF) is currently being developed transforming wood into high-value end-products. RCF is considered to be in the pilot stage with a technology readiness level of 5-6. Apart from the RCF-process characteristics, the economic feasibility also depends on the investment decisions that are made upstream and downstream within the wood value chain, increasing the level of uncertainty. Two investment options within the value chain are considered: an option to invest in harvesting equipment and an option to invest in the RCF. To understand the impact of multiple sources of uncertainty on the decision to invest in an innovative RCF-driven wood value chain, an analytical two-factor real options model is presented, accounting for correlated cost and price uncertainties. Two different scenarios, separated and united investments in harvesting equipment and RCF, are analyzed. In both scenarios, market uncertainty postpones investment in comparison to the traditional NPV approach. When both investments are considered separately, the investment in RCF is expected to be earlier than the investment in harvesting equipment. When both investment decisions are united, the probability of investment increases. The study reveals that RCF has the potential to stimulate investments from different investors, -upstream and midstream-, within the wood value chain. Besides, the introduced real options model proofs its ability to assess the economic feasibility of innovative technologies (e.g RCF) individually or within the value chain, taking into account multiple sources of uncertainty.

Recent advances in the valorization of plant biomass

Plant biomass is a highly abundant renewable resource that can be converted into several types of high-value-added products, including chemicals, biofuels and advanced materials. In the last few decades, an increasing number of biomass species and processing techniques have been developed to enhance the application of plant biomass followed by the industrial application of some of the products, during which varied technologies have been successfully developed. In this review, we summarize the different sources of plant biomass, the evolving technologies for treating it, and the various products derived from plant biomass. Moreover, the challenges inherent in the valorization of plant biomass used in high-value-added products are also discussed. Overall, with the increased use of plant biomass, the development of treatment technologies, and the solution of the challenges raised during plant biomass valorization, the value-added products derived from plant biomass will become greater in number and more valuable.

Unraveling the environmental impacts of bioactive compounds and organic amendment from grape marc

In a society that produces large amounts of solid waste, the search for new methods of valorisation has led to the development of techniques that make it possible to obtain new products from waste. In the case of bio-waste, biological treatment such as anaerobic digestion or composting appear to be suitable options for producing bio-energy or bio-fertilizers respectively. Vermicomposting is a method of converting solid organic waste into resources through bio-oxidation and stabilization of the organic waste by earthworms. The purpose of this study is to establish the environmental impacts of a complete route for the valorisation of grape pomace in order to identify environmental hotspots. In this valorisation route, different value-added products are produced with potential application in the cosmetic, food and pharmaceutical sectors. Priority was given to the use of primary data in the elaboration of the data inventories needed to perform the life cycle assessment (LCA). The main findings from this study reported that the energy requirement of the distillation process is an important hot spot of the process. Although the valorisation route has some poor results in terms of the two environmental indicators (carbon footprint and normalised impact index), when economic revenues were included in this analysis, its environmental performance was better than that of other alternatives for bio-waste recovery.

Recent advances in organosolv fractionation: Towards biomass fractionation technology of the future

Organosolv treatment is among the most promising strategies for valorising lignocellulosic biomass and could facilitate the transition towards enhanced utilization of renewable feedstocks. However, issues such as inefficient solvent recycle and fractionation has to be overcome. The present review aims to address these issues and discuss the role of the components present during organosolv treatment and their influence on the overall process. Thus, the review focuses not only on how the choice of solvent and catalyst affects lignocellulosic fractionation, but also on how the choice of treatment liquor influences the possibility for solvent recycling and product isolation. Several organic solvents have been investigated in combination with water and acid/base catalysts; however, the lack of a holistic approach often compromises the performance of the different operational units. Thus, an economically viable organosolv process should optimize biomass fractionation, product isolation, and solvent recycling.

Insights from the Sustainability Monitoring Tool SUMINISTRO Applied to a Case Study System of Prospective Wood-Based Industry Networks in Central Germany

Bioeconomy regions are a young concept representing emerging amalgamation points for the implementation of cross-sectoral value-added chains. When sustainable bioeconomy strategies are rolled out, their proof-of-concept implies that industrial R&D activities should lead to impact decoupling and that the valorization of locally available lignocellulosic biomass has to contribute to an increase in added value. Furthermore, regional co-benefits for society and a positive influence on local environmental and socioeconomic conditions are major factors. The fulfillment of these strategic goals would be a milestone achievement when progressing from the blueprint development and the road-mapping stage towards socially accepted and sustainable wood-based bioeconomy strategies. For regional industrial and science stakeholders who run pilot facilities for process upscaling and for energy and material flow integration, this requires well-orchestrated integrative processes, which go beyond conventional “Life Cycle Management” approaches. It is obvious that assessing and monitoring such integrative systems will have to account for different stakeholder perspectives and for detailed technology deployment and resource conversion scenarios. Applying a sustainability index methodology in a case study region must include an evaluation of the whole supply chain and the process networks associated with the characteristic products of the evaluated region. To date, no such integrative assessment methods exist in the literature. Therefore, the aim of this paper is to lay out, on the basis of a practical example in the case study region of Central Germany, an assessment of the sustainability level of wood-based bioeconomy networks by applying the Sustainability Monitoring Tool -SUMINISTRO”- to examine regional bio-based industry networks.

Biodiesel and Hydrogen Production in a Combined Palm and Jatropha Biomass Biorefinery: Simulation, Techno-Economic, and Environmental Evaluation

The biodiesel from lignocellulosic materials has been widely recognized as an alternative fuel to meet energy requirements worldwide, facing fossil fuel depletion, and emerging energy policies. In this work, the biorefinery approach was applied for biodiesel production from jatropha and palm oils in order to make it economically competitive by the utilization of residual biomass as the feedstock for obtaining hydrogen via steam reforming of glycerol and gasification. The linear chains for hydrogen and diesel were simulated using UniSim software and main stream properties were collected from the literature or predicted by correlations. The proposed scheme of biorefinery was analyzed through environmental and techno-economic assessment to identify the feasibility of this process to be implemented. Three different blends of oils (JO10-PO90, JO20-PO80, and JO30-PO70) were considered in the environmental analysis to determine alternatives for reducing potential environmental impacts (PEIs). It was found that the acidification potential highly contributed to the environmental impacts attributed to the use of fossil fuels for heating requirements, and JO30-PO70 blend exhibited the lowest PEI value. The economic indicators were calculated to be 8,455,147.29 $USD and 33.18% for the net present value and internal rate of return, respectively. These results revealed that the proposed combined biomass biorefinery is feasible to be scaled up without causing significant negative impacts on the environment.

An Environmental and Economic Analysis of Flocculation Technology Applied to a Corn-Based Ethanol Plant

The stimulation of renewable fuel production is related to the environmental issues resulting from the extraction and utilization of fossil fuels. Although corn-based ethanol is one of the leading renewable fuels and promises to mitigate these environmental impacts, it generates large volumes of wastewater with high concentrations of organic material (CODcr > 30,000 mg/L) and low pH (3.5–4.5), which leads to serious environmental concerns. A common method of treatment of distillery wastewater is the Dry Distilled Grain Soluble (DDGS) process, which separates liquid and solid fractions; however, a disadvantage of this process is its high energy consumption. Other commonly implemented methods are often costly and not environmentally safe. To minimize these problems, a flocculation process can be applied as a potential lower energy consumption process utilizing bioflocculants, which have been proven harmless to the environment. Therefore, the main goal of this study was to analyze the economic and environmental impacts of using bioflocculants instead of evaporation process in a corn-based ethanol plant. The procedures were evaluated by analyzing the Life Cycle Assessment (LCA) and Techno-Economic Analysis (TEA). From the results, it can be seen that the flocculation system can be an alternative process for effectively minimizing energy consumption during the production of DDGS, Distilled Wet Grains with Solubles (DWGS), and corn oil. The flocculation process achieved a significantly (28%) lower utility cost when compared to the conventional system. However, the overall fixed costs and annual operating costs for the flocculation system were higher than those of the conventional system. Additionally, both processes resulted in negative profit and a sensitivity analysis showed that the feedstocks cost substantially impacted the DDGS, DWGS, and corn oil production costs. Related to environmental aspects, the LCA results showed that the flocculation process achieved the lowest Global Warming Potential (GWP) of the several electricity supply technologies analyzed and presented a significant reduction in CO2 equivalent emissions when compared to a conventional system. The flocculation process resulted in approximately 57% lower greenhouse gas emissions.

Lignocentric analysis of a carbohydrate-producing lignocellulosic biorefinery process

A biologically-based lignocellulosic biorefinery process for obtaining carbohydrates from raw biomass was investigated across six diverse biomasses (three hardwoods & three nonwoods) for the purpose of decoding lignin's influence on sugar production. Acknowledging that lignin could positively alter the economics of an entire process if valorized appropriately, we sought to correlate the chemical properties of lignin within the process to the traditional metrics associated with carbohydrate production-cellulolytic digestibility and total sugar recovery. Based on raw carbohydrate, enzymatic recovery ranged from 40 to 64% w/w and total recovery ranged from 70 to 87% w/w. Using nitrobenzene oxidation to quantify non-condensed lignin structures, it was found that raw hardwoods bearing increasing non-condensed S/V ratios (2.5-5.1) render increasing total carbohydrate recovery from hardwood biomasses. This finding indicates that the chemical structure of hardwood lignin influences the investigated biorefinery process' ability to generate carbohydrates from a given raw hardwood feedstock.

Formic acid aided hot water extraction of hemicellulose from European silver birch (Betula pendula) sawdust

Hemicellulose has been extracted from birch (Betula pendula) sawdust by formic acid aided hot water extraction. The maximum amount of hemicellulose extracted was about 70mol% of the total hemicellulose content at 170°C, measured as the combined yield of xylose and furfural. Lower temperatures (130 and 140°C) favored hemicellulose hydrolysis rather than cellulose hydrolysis, even though the total hemicellulose yield was less than at 170°C. It was found that formic acid greatly increased the hydrolysis of hemicellulose to xylose and furfural at the experimental temperatures. The amount of lignin in the extract remained below the detection limit of the analysis (3g/L) in all cases. Formic acid aided hot water extraction is a promising technique for extracting hemicellulose from woody biomass, while leaving a solid residue with low hemicellulose content, which can be delignified to culminate in the three main isolated lignocellulosic fractions: cellulose, hemicellulose, and lignin.