Biogenic Carbon Research Articles

Towards a Carbon Accounting Framework for Assessing the Benefits of Biogenic Wood Carbon to Net Zero Carbon Targets

Carbon stored in harvested wood products (HWPs) can play an important role in climate change mitigation and needs to be accounted for accurately and consistently. This study reviewed the features of previous HWP carbon accounting frameworks and discussed potential improvements for a more complete assessment of all HWP contributions to net zero carbon targets at subnational levels. The basic features include the components, the methods, the approaches, and the modeling principles. A key recommendation is to expand previous HWP C accounting framework components to include other climate change mitigation benefits such as local or regional substitution effects (i.e., material replacement, fossil fuel displacement effects, energy efficiency gains, recycling effects, and cascading use impacts) of all produced and consumed HWPs. Another area for improvement is the need for subnational unit-specific activity data and conversion factors. Adopting variants of the domestic origin-stock change approach will also help account for relevant production and consumption activities within the subnational unit. These recommendations will enhance the accuracy and/or precision of HWP accounting frameworks at the subnational level and help capture all potential benefits of HWPs as a carbon sink for climate change mitigation and a valuable contributor to subnational net zero carbon targets.

New model for evaluating greenhouse gas emissions from sludge treatment based on fossil and biogenic carbon migration

The treatment and disposal of massive amounts of sewage sludge are potential emission sources of greenhouse gases (GHGs) which strongly depend on the migration of fossil and biogenic carbon into GHGs. Owing to the lack of fossil carbon data and suitable estimation models, CO2 emissions generated from sludge combustion and biodegradation are considered carbon-neutral according to the Intergovernmental Panel on Climate Change (IPCC), increasing the inaccuracy of GHG emissions accounting. Therefore, this study aimed to build a new comprehensive assessment model to accurately evaluate GHG emissions from four typical sludge treatment and disposal approaches. Notably, fossil and biogenic carbon migration were considered, rather than the emission factor method when measuring direct GHG emissions. The results of 14C analysis, which quantified the contributions of fossil and biogenic carbon to the sludge samples, showed significant differences in the average fossil carbon fractions among the four types of sludge: 84.11% for chemical sludge, 25.99% for tannery sludge, 79.19% for textile dyeing sludge, and 45.97% for municipal sludge. According to our model, the route of safely landfilling deep-dewatered sludge possessed the highest GHG emission factors of 1.18–3.75 tCO2eq/t dry sludge. The optimal sludge treatment option was anaerobic digestion followed by land application. This treatment maintained a low and stable level of GHG emissions (0.48–0.54 tCO2eq/t dry sludge) and exhibited low sensitivity to changes in fossil carbon fraction and carbon content according to the sensitivity analysis results. For sludge with a high calorific value and a low fossil carbon fraction, the route of dry incineration + utilization of ash and slag as building materials was carbon-negative and more suitable than anaerobic digestion to achieve carbon neutrality. This study complements the fossil carbon data gaps of sludge in the IPCC Guidelines and provides a more accurate GHG emissions accounting model, which will support the sludge treatment industry in developing effective strategies to reduce GHG emissions.

Biogenic Carbon Dot-Embedded Chitosan Hydrogels as a Two-Stage Fluorescence OFF–ON Probe for Sequential and Ratiometric Detection of Fe(III) and Glutathione

Biogenic Carbon Dot-Embedded Chitosan Hydrogels as a Two-Stage Fluorescence OFF–ON Probe for Sequential and Ratiometric Detection of Fe(III) and Glutathione

Native Gold and Unique Gold–Brannerite Nuggets from the Placer of the Kamenny Stream, Ozerninsky Ore Cluster (Western Transbakalia, Russia) and Possible Sources

We carried out a comprehensive study of native gold (morphology, composition, intergrowths, and microinclusions) from alluvial deposits of the Kamenny stream (Ozerninsky ore cluster, Western Transbaikalia, Russia). The study showed that there were four types of native gold, which differed significantly in their characteristics and probably had different primary sources from which placers were formed: gold–quartz, oxidized gold–sulfide, gold–silver, and zones of listvenites with copper–gold and gold–brannerite (Elkon-type). Particular attention was paid to the study of unique, both in size and in composition, gold–brannerite nuggets of the Kamenny stream. It was established that the gold in the gold–brannerite nuggets (GBNs) had wide variations in chemical composition and mineral features. According to them, there were five different fineness types of native gold: 750–800‰; 850–880‰; 880–920‰; 930–960‰; and 980–1000‰. The data obtained indicated a multistage, possibly polygenic, and probably polychronous formation of GBN gold–uranium mineralization. The first stage was the formation of early quartz–nasturanium–gold–W–rutile–magnetite association (Middle–Late Paleozoic age). The second was the crystallization of brannerite and the replacement of an earlier pitchblende with brannerite (Late Triassic (T3)–Early Jurassic (J1) age). The third was the formation of the hematite–barite–rutile–gold association as a result of deformation–hydrothermal processes, which was associated with the appearance of zones of alteration in brannerite in contact with native gold with 8–15 wt.% Ag. The fourth was hypergene or the low-temperature hydrothermal alteration of minerals of early stages with the development of iron hydroxides (goethite) with impurities of manganese, tellurium, arsenic, phosphorus, and other elements. The carbon isotopic composition of an organic substance indicates the involvement of a biogenic carbon source. In the OOC area, there were signs that the composition of the GBNs and the quartz–chlorite–K–feldspar-containing rocks corresponded to Elkon-type deposits.

Calculating a Land Carbon Accounting Factor in the United States: an Example and Implications

Abstract Companies that produce and use wood for products and energy find it increasingly important to communicate the carbon balance and potential climate effects of these activities. Computing forest carbon stocks and stock changes, and emissions from operations, are often part of institutional reporting for environmental, social, and governance purposes. This article describes an example methodology to assess forest carbon changes associated with the harvesting of wood products and proposes metrics that could be used to allocate harvesting effects to individual organizations for their reporting purposes. We discuss boundaries (types of forests and carbon pools to include), spatially appropriate evaluations given uncertainty, temporal considerations, risk of reversals, and allocation of net sequestration to products sourced from the region. We also discuss the complex nature of the biogenic carbon cycle and warn about the appropriate interpretation of this methodology.

Fabrication of biogenic carbon-based materials from coconut husk for the eradication of dye

The highly biocompatible nature of carbon dots (CQDs) and potential usage in waste water treatment makes them as one of the effective alternative for treating water pollution. Herein, biogenic carbon dots (CQDs) with size range of 2 nm were prepared from waste coconut husk as a precursor source. The hydrophilic nature and higher surface area of as prepared CQDs has further supported the superior adsorption efficiency of more than 90% for Victoria blue B (VB) dye from waste water samples. Different dye adsorption parameters including adsorbate and adsorbent dosage, pH of reaction media and equilibrium time have been optimized and found that 8 mg of adsorbent was sufficient to remove 70 mg VB dye in 4 mL aqueous solution in 60 min at pH = 7. The adsorption kinetic (2nd order) and isotherms (Freundlich-type) were well followed on prepared CQDs. The reusability studies up to 5 times with minimal decrement of 4% confirm the constancy of CQDs for the adsorptive removal of VB. The methodology presents a greener way for overcoming ecological issues with sustainable materials in an economical manner.

Net zero greenhouse emissions and energy recovery from food waste: manifestation from modelling a city-wide food waste management plan

Food waste (FW) being a major solid waste component and of degradable nature is the most challenging to manage and mitigate greenhouse gas emissions (GHEs). Policymakers seek innovative approaches to achieve net zero objectives and recover resources from the FW which requires a comparative and holistic investigation of contemporary treatment methods. This study assessed the lifecycle of six alternative scenarios for reducing net GHEs and energy use potential from FW management in a metropolis, taking Hong Kong as a reference. In both impact categories, the business-as-usual (landfilling) was the worst-case scenario. The combined anaerobic digestion and composting (ADC) technique was ranked best in the global warming impact but was more energy intensive than anaerobic digestion with sludge landfilling (ADL). Incineration ranked second in net GHEs but less favourable for energy recovery from FW alone. The proposed integration of FW and biological wastewater treatment represented an enticing alternative. Integration by co-disposal and treatment with wastewater (CoDT-WW) performed above average in both categories, while anaerobic co-digestion with sewage sludge (AnCoD-SS) ranked fourth. The sensitivity analysis further identified critical parameters inherent to individual scenarios along with biogenic carbon emission and sequestration, revealing their significance on the magnitude of GHEs and scenarios’ ranking. Capacity assessment of the studied treatment facilities showed a FW diversion potential of ∼60% while reducing the net GHEs by ∼70% compared to the base-case, indicating potential of net zero carbon emissions and energy footprint by increasing treatment capacity. From this study, policymakers can gain insights and guidelines for low-carbon urban infrastructure development worldwide.

Assessing feasible H2–CO2 sources in the US as Feedstocks for Sustainable Aviation Fuel Precursors: Acetic Acid and Ethanol Production via Hydrogenotrophic Pathways

The environmental impact of carbon dioxide emissions is significant, and research is focused on mitigating these emissions and developing eco-friendly technologies in line with green chemistry principles. Waste-to-energy technologies play a crucial role in converting waste into renewable energy and valuable biofuels and bioproducts. This study specifically explores the utilization of waste gas emissions, particularly carbon dioxide, from various sources in the United States for the production of sustainable aviation fuel (SAF) precursors, such as ethanol and acetic acid. The study categorizes and quantifies the volumes of carbon dioxide emissions into three types: non-biogenic, biogenic, and biogenic emissions from ethanol production facilities. Stoichiometric calculations are applied to compare the amounts of carbon dioxide from each category with the available hydrogen production capacity, determining if sufficient hydrogen is present for converting carbon dioxide into SAF precursors. The study reveals two key findings. Firstly, there is a significant reserve of carbon dioxide, approximately 1648 million metric tons per year (MMTy), combining all three categories, which would require a substantial increase of approximately 35–40 times in the existing hydrogen production capacity of 4.988 MMTy. This increased hydrogen production has the potential to yield approximately 1067.82 MMTy of acetic acid and 189.19 MMTy of ethanol annually. Secondly, upon analyzing the quality and application of the three sources of carbon dioxide with the currently available hydrogen production capacity, it is found that biogenic carbon dioxide from ethanol plants is the most suitable choice for immediate production of SAF precursors. This would theoretically result in an annual production of 1.36 MMTy of ethanol and 1.772 MMTy of acetic acid. The other two sources of carbon dioxide can be considered potential reserves for future utilization when additional hydrogen production facilities are established.The study provides a foundation for assessing the aggregation potential required for acetic acid and ethanol production. By optimizing the use of waste gases as raw materials, the study not only enables the production of SAF precursors but also contributes to the passive reduction of greenhouse gas emissions.

Exploring the potential of roof greening for low-carbon landscapes.

As one type of urban artificial ecosystems, roof greening exhibits carbon source/sink characteristics during their life cycle. The carbon cycle mechanism is complex. The lack of exhaustive carbon performance quantification methods and assessment indicators hinders the promotion and implementation of green roof urban decarboni-zation. Focusing on the quantification of roof greening low-carbon landscape potential, we analyzed the internal carbon cycle mechanism of green roof systems and explored four carbon reduction and sink pathways (P1-P4): biogenic carbon sink, embodied carbon, operational carbon, and bioenergy supply. Based on the dual performance indicators of normalized value of carbon emissions and carbon payback time, we summarized the normalized value measurement method of each pathway. The potential and characteristics of each pathway were quantified by extracting data from the literature. The results showed that the quantified potential values for P1 to P4 were 9.54, -2.26, 2.96 and 0.35 kg CO2·m-2·a-1, respectively, and that the potential values for each pathway were strongly influenced by plant types, climate, and other factors. The imperfect base database and the heterogeneity of assessment scenarios impacted the accuracy of the measurements. The integrated low carbon landscape potential of extensive green roofs was discussed in sub-scenarios, with the 40-year-life cycle integrated carbon reduction ranging from 92.24 to 433.42 kg CO2·m-2 and the carbon payback period ranging from 5 to 14 years. Finally, we summarized the problems in the assessment to facilitate future updates and improvements.

The sequence matters: Expert opinions on policy mechanisms for bioenergy with carbon capture and storage

This paper presents the results of a globally distributed survey on policies for incentivizing bioenergy with carbon capture and storage (BECCS). The current lack of policy incentives to support the implementation of BECCS constitutes a major deployment barrier. Therefore, scientists and policymakers are now debating the optimal BECCS policy framework. Previous studies have presented theoretical analyses of policy options to spur deployment, yet despite the considerable influence of experts on policy processes, very few studies have explored expert opinions. Drawing on an online survey of experts (N = 46), we explore their policy preferences and whether those preferences differ or converge between experts from different working sectors. The results show that a tax and refund scheme, a flat-rate subsidy, and reverse auctioning are considered more suitable than other measures. Furthermore, most experts agree that rather than a stand-alone policy, a policy mix would be needed in order to support BECCS deployment. Several experts propose a sequence of policies, moving from publicly funded supply-push policies in the short term to budget-neutral demand-pull policies in the longer term. Regarding various subsidy schemes, respondents favor investment subsidies or results-based subsidies based on stored biogenic carbon dioxide. The relatively minor differences in the response patterns between groups of experts suggest that a consensus on a preferred BECCS policy pathway might be forming across different sectors and interest groups. Therefore, our results could inform policymakers on policy instruments for BECCS that are considered most suitable by experts and thus help to shape the policy pathway for BECCS.

Ziziphus mauritiana-derived nitrogen-doped biogenic carbon dots: Eco-friendly catalysts for dye degradation and antibacterial applications

In this study, the naturally available Ziziphus Mauritiana was used as a bioresource for the preparation of bifunctional nitrogen doped carbon dots (N-CDs). The doping of nitrogen into the graphitic carbon skeleton and the in-situ formation of N-CDs were systematically identified by the various structural and morphological studies. The green fluorescent N-CDs were used as active catalysts for the removal of Safranin-O dye and achieved 79 % removal efficiency. Furthermore, the prepared N-CDs were used to evaluate antibacterial activity with four different bacterial species, such as Shigella flexneri, Staphylococcus aureus, Streptococcus pyogenes, and Klebsiella pneumoniae. Amongst these, the highest antimicrobial activity was achieved against Klebsiella pneumonia, with a maximum zone of inhibition of 14.6 ± 1.12 at a concentration of 100 g mL−1. Thus, the obtained results demonstrate the cost efficient bifunctional application prospects of N-CDs to achieve significant catalytic and antibacterial activities.

Life cycle cost, energy, and carbon emissions of molds for precast concrete: Exploring the impacts of material choices and additive manufacturing

Molds for precast concrete are commonly used to create simple- to complex-shaped concrete products away from construction sites. These molds are often handmade from wood; however, additively manufacturing (AM, or 3D printing) fiber-reinforced polymer composites is an advantageous alternative, producing significantly more durable, highly complex molds faster, but likely at a higher cost. This study explores the impact of material and production variables on the cost, energy, and carbon emissions of employing composite AM molds over the full lifecycle. The case study employed techno-economic and life cycle assessments to show that using wood flour–poly(lactic acid) or recycled carbon fiber–acrylonitrile butadiene styrene for AM molds can be less expensive than conventional wood molds, especially when considering use phase costs. While wood molds have the least environmental impacts due to wood's higher biogenic carbon sequestration and minimal processing, optimizing AM designs could reduce energy demand, carbon emissions, and cost.

Compressive load resistance of straw bale assemblies under concentric and eccentric loading

To reduce the significant carbon emissions associated with construction materials, there is growing recognition of the potential for bio-based resources, including materials derived from agricultural crops such as straw, hemp and flax. The biogenic carbon stored with plant based materials can significantly reduce carbon emissions compared to other products. Uses of bio-based materials are however generally limited to non-structural, in particular as insulation, but in contrast to many other solutions straw bales can also be used structurally in low-rise construction. Despite the use of straw bales for over 100 years there is still relatively little known about their compression performance, and there are no recognised guides or standards to support structural engineers. This paper describes an experimental study into the load carrying capacity of straw bale wall assemblies. In keeping with practice in the UK, and different to previous North American studies, the wall plates do not directly bear onto the plaster coats. The aim of the paper is to characterise and compare the vertical load carrying performance of straw bale walls without and with plaster coatings, and study the effect of wall height, plaster use, and load eccentricity on compressive resistance. A series of wall assemblies were built from stacking 1 m long wheat straw bales. Wall assembly heights varied with the number of bale courses: one, two, three and four bales high. In total results from 29 tests are presented. Key findings of the study concern the influence of load eccentricity, use of plaster and wall geometry on compression performance. In the absence of national guidance, the results of this experimental study will support structural engineers designing loadbearing straw bale walls.

Impact of Biogenic Carbon Neutrality Assumption for Achieving a Net-Zero Emission Target: Insights from a Techno-Economic Analysis.

Global pathways limiting warming to 2 °C or below require deep carbon dioxide removal through a large-scale transformation of the land surface, an increase in forest cover, and the deployment of negative emission technologies (NETs). Government initiatives endorse bioenergy as an alternative, carbon-neutral energy source for fossil fuels. However, this carbon neutral assumption is increasingly being questioned, with several studies indicating that it may result in accounting errors and biased decision-making. To address this growing issue, we use a carbon budget model combined with an energy system model. We show that including forest sequestration in the energy system model alleviates the decarbonization effort. We discuss how a forest management strategy with a high sequestration capacity reduces the need for expensive negative emission technologies. This study indicates the necessity of establishing the most promising forest management strategy before investing in bioenergy with carbon capture and storage. Finally, we describe how a carbon neutrality assumption may lead to biased decision-making because it allows the model to use more biomass without being constrained by biogenic CO2 emissions. The risk of biased decision-making is higher for regions that have lower forest coverage, since available forest sequestration cannot sink biogenic emissions in the short term, and importing bioenergy could worsen the situation.

Product stage embodied greenhouse gas reductions in single-family dwellings: Drivers of greenhouse gas emissions and variability between Toronto, Perth, and Luzon

Reducing embodied greenhouse gas (GHG) emissions in the construction of buildings is increasingly recognized as necessary to meet medium- and long-term climate targets. The focus of efforts to reduce embodied GHG have been on using lower GHG intensity materials through material switching (e.g., wood vs concrete buildings) or changing the manufacturing of materials to reduce their GHG intensity (e.g., blast oxygen furnace to electric arc furnace in steel manufacturing). There has been much less attention directed toward the potential to reduce embodied GHG emissions by reducing the amount of material used for the construction of buildings. This study estimates the embodied GHG emission intensity of single-family dwellings (SFD) in Toronto, Canada, Perth, Australia, and Luzon, Philippines using a carbon neutral approach (excluding biogenic carbon) and focusing on the product stage (A1-A3). This examines the main drivers of embodied GHG emissions and quantifies the pathways to reduce embodied GHG emissions of SFDs. The mean embodied GHG emission intensities of SFDs vary across locations with differences driven by construction type and in upstream manufacturing of materials. The mean embodied GHG emission intensities in studied SFDs are 137 kg CO2 eq/m2 for Toronto, 190 kg CO2 eq/m2 for Perth, and 313 kg CO2 eq/m2 for Luzon. Monte Carlo simulation and principal component regression show that the variation in embodied GHG emission intensity within the studied cases is dominated by material quantities with less influence from material GHG intensity. Structural light-weighting, more intensive use of buildings, and very low material GHG factors collectively are shown to have the potential to reduce embodied emissions by 45%–60%. Strategies tested illustrated that savings on the order of 20% are readily available through more intensive use and structural lightweighting. Aggressive changes in energy sources and material manufacturing would take longer to achieve but could deliver another 22%–37% in emissions reductions.

Co-processing of solid recovered fuels from mixed municipal and commercial waste in the cement industry - A pathway to a circular economy.

With global municipal solid waste generation increasing steadily, the importance of high-quality, environmentally friendly waste valorization methods is rising, too. Most countries have set themselves ambitious recycling goals and follow a waste hierarchy in which recycling is more preferable than energy recovery. This article focuses on a waste treatment option that already is an integral part of waste management in some countries and enables the simultaneous recovery of energy and mineral constituents: the production of solid recovered fuels (SRFs) from mixed municipal and commercial waste and their use in the cement industry is often referred to as co-processing. The state of the art of SRF production is described and the first comprehensive dataset for SRF samples including major constituents, heavy metal and metalloid contents, energy- and CO2-emission-relevant parameters, ash constituents and the material-recyclable share of SRF is presented. Additionally, a comparison with fossil fuels is given. It is concluded that SRF from state-of-the-art production plants complies with strict limit values for heavy metals, has an average biogenic carbon content of 60%, and its application in the cement industry can be considered as partial recycling (14.5%) and partial energy recovery (85.5%). Leaving no residues to be dealt with, co-processing of waste in the cement industry therefore offers many benefits and can support the shift from a linear to a circular economy.

Life Cycle Assessment of the Environmental Benefits of Using Wood Products and Planting Trees at an All-Electric University Laboratory

Many countries across the globe have set targets for different economic sectors, aiming to tackle global warming by reducing the overall carbon footprint of human-related activities. Among these sectors, the building industry stands out as a major consumer of materials and energy resources, making it a key player in achieving carbon neutrality. It is one of the main contributors responsible for energy-related greenhouse gas (GHG) emissions, including both operational emissions and embodied emissions in materials and equipment manufacturing. Nature-based design solutions, such as planting trees in urban spaces, or incorporating the use of wood products, have regained attention in recent years due to their potential to mitigate carbon emissions from buildings. Within this context, this paper presents a comprehensive life cycle assessment (LCA) of a recently built research facility, with a focus on demonstrating how the benefits of nature-based solutions, specifically carbon sequestration from trees and biogenic carbon content in wood products, can be quantified and reported using the latest LCA standards and tools. The analysis is provided under three end-of-life scenarios for wood products: wood incineration with energy recovery, wood landfilling, and wood recycling/repurposing. The results indicate that the set of strategies adopted in this building, i.e., tree planting, the use of wood products, and the end-of-life treatment of materials, can potentially offset carbon emission by 37.2% up to 83.9% when included in the LCA, depending on the scenario considered. By continuing to refine LCA standards and tools, and fostering collaboration between researchers, policymakers, and industry professionals, we can advance our understanding and ultimately achieve the widespread adoption of carbon-neutral buildings.

GHG emissions from building renovation versus new-build: incentives from assessment methods

A variety of life cycle assessment (LCA) calculation methods and rules exist in European countries for building performance evaluation based on new-build. However, the increased focus on the retention and renovation of the existing building stock raises questions about the appropriateness of these the methods and rules when applied to renovation cases. Using a real renovation case, Danish, Finnish and Swedish LCA-based greenhouse gas emissions (GHGe) assessments are assessed for how they position building renovation in relation to demolition and new-build reference values. The influence of these three different methods is examined for future development policies. Results show that upfront emissions for renovation are significantly lower for all approaches. The Swedish approach had the lowest GHG emissions compared with a scenario with demolition and new-build due to the method, which only includes upfront emissions of new materials. The Danish and Finnish renovation cases each performed worse in comparison with the new-build future emissions, specifically from operational energy use. Therefore, method development should consider incentives for upfront and future emissions. Furthermore, methods could account for the existing materials in the building, which are included in the Danish and Finnish approaches. This would provide incentive for renovation and reuse. Policy relevance Future policymaking needs to consider the influence of LCA methods on climate impact assessment of building renovations. The temporal differences occur when renovation is compared with demolition and new-build. Policy needs to take account of these temporal differences for apportioning GHG emissions between upfront and future emissions. A key question is whether existing materials should be included in the assessment as this would incentivise the reuse of these materials. Differences in accounting for the impacts of biogenic carbon in materials yields different results. This is a key issue in carbon accounting and will influence future practice.

Mono-material product design with bio-based, circular, and biodegradable polymers

Mono-material product design with bio-based, circular, and biodegradable polymers

Reducing life cycle material, energy and emissions for liquid consumer products through printing

Packaging is either the largest or second-largest source of energy as well as multiple different environmental burdens across the lifecycle of many different beverages. Here we analyze the potential of a new approach to consuming beverages (and potentially other household liquids) with less energy and environmental burden. This involves printing the active ingredients on to a cup to which water is added just before consumption. When consumed with tap-water, beverages printed on PLA cups require 20%, 40% and 90% less packaging materials relative to Aluminum, plastic and glass-based packaging respectively. This yields a 23% – 48% reduction in lifecycle primary energy and 40% – 57% reduction in global warming potential (50% – 70% with biogenic carbon credit for landfilled-PLA). Sensitivity analyses suggest that the single greatest source of uncertainty in benefits of printed beverages is of a behavioral nature -whether one uses tap- or commercially bottled- water, which eliminates the benefits of printed beverages.