Search

Direct air capture (DAC) is a sustainable technology to alleviate the greenhouse effect and a reliable pathway to acquire inexhaustible CO2 for the production of costly chemicals and energy products. Current DAC technologies with amine‐related sorbents rely on chemisorption, while they consume intensive energy for CO2 release and sorbent regeneration by heating. Developing new DAC processes with weak, reversible adsorption can substantially reduce the regeneration energies. Herein, the design of CO2 breathing paper (CBP) is demonstrated toward spontaneous CO2 extraction from ambient air and solar‐driven regeneration. The CBP is fabricated by coupling 2‐ethyl‐4‐methylimidazole to carbon nanotube paper on the basis of density functional theory calculations. At ambient conditions, CBP spontaneously captures atmospheric CO2 with a capacity of 0.14–1.75 mmol g–1 at 0–35 °C through non‐covalent electrostatic interaction. Upon exposure to sunlight, all adsorbed CO2 can be released and converted to concentrated gas for storage. Attractively, the efficiency of solar‐driven CO2 release is much higher than the traditional temperature‐swing method owing to the IR sensitivity of CO2. Besides the reversibility, the mild conditions also ensure the durability of CBP. These findings suggest that the CBP is a promising candidate for cost‐effective DAC. [ABSTRACT FROM AUTHOR]

The objective of this study was to measure the anaerobic biodegradation of different types of paper products in laboratory-scale landfill reactors. The study included (a) measurement of the loss of cellulose, hemicellulose, organic carbon, and (b) measurement of the methane yields for each paper product. The test materials included two samples each of newsprint (NP), copy paper (CP), and magazine paper (MG), and one sample of diaper (DP). The methane yields, carbon storage factors and the extent of cellulose and hemicellulose decomposition all consistently show that papers made from mechanical pulps (e.g., NPs) are less degradable than those made from chemical pulps where essentially all lignin was chemically removed (e.g., CPs). The diaper, which is not only made from chemical pulp but also contains some gel and plastic, exhibited limited biodegradability. The extent of biogenic carbon conversion varied from 21 to 96% among papers, which contrasts with the uniform assumption of 50% by the Intergovernmental Panel on Climate Change (IPCC) for all degradable materials discarded in landfills. Biochemical methane potential tests also showed that the solids to liquid ratio used in the test can influence the results., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Insulating paper is the key material utilized in ultra-high voltage (UHV) projects, and it affects the safe and stable operation of the whole power system. Cellulose fiber-based insulating paper, having the advantages of low price and environmental friendliness, has been widely used as the preferred insulating material for certain transformers. Bamboo, as a fast-growing raw material, has a favorable fiber length and its carbon sequestration is better than that of wood. Bamboo can be potentially used as a new raw material for insulating paper, thus promoting the green development of the power and paper industry. This article mainly discusses the challenges and potentials of bamboo fiber-based insulating paper and the opportunities of bamboo fiber-based paper materials.

The article focuses on pairing carbon captured from industrial processes with novel electrochemical reactions, particularly involving pulp and paper waste. Topics include enhancing energy efficiency by 10% compared to traditional methods, utilizing 5-hydroxymethylfurfural (HMF) from biowaste to produce 2,5-furandicarboxylic acid (FDCA) for biodegradable plastics, and developing efficient catalyst systems for industrial-scale carbon dioxide reduction.

The text provides a summary of various articles related to air quality, climate change, and environmental initiatives. It mentions a report from the World Meteorological Organization (WMO) highlighting record-breaking climate change indicators in 2023, the use of pulp and paper waste to reduce carbon emissions, the development of national indoor quality standards for public buildings, the establishment of a hydrogen hub in the Pilbara region of Australia, and the U.S. Environmental Protection Agency's new tailpipe rules to reduce pollution from cars and light trucks. These articles offer insights into the current state of the environment and efforts to address climate change. [Extracted from the article]

Bioenergy with carbon capture and storage (BECCS) is one of the key negative emission technologies (NETs). Large-scale implementation of BECCS has been criticized of the associated increase in land use. The existing large Nordic pulp and paper production units enable BECCS deployment without additional land use, as they currently release large amounts of bio-based carbon dioxide (CO2). The application of BECCS in pulp mills has been found technically feasible in earlier studies. This study explores key factors that affect the propensity to invest in BECCS in different types of existing European pulp and paper mills. The results give fresh understanding on the effects of BECCS on the market price of pulp and paper products and the required level of incentives. Based on statistical data, the marginal carbon dioxide credit (€ per ton CO2) to make BECCS profitable was derived. The results show that the required level of credit greatly depends on the mill type and details and that the feasibility of BECCS does not clearly correlate with the economic performance or the measured efficiency of the mill. The most promising mill type, a market kraft pulp mill, would find BECCS profitable with a credit in the range of 62–70 €/tCO2 and a credit of 80 €/tCO2 would decrease pulp production costs by 15 €/tproduct on average if 50% of CO2 emissions was captured. The EU Emission Trading System (ETS) is the main policy instrument to achieve the climate targets related to fossil energy use, but does not yet contemplate bio-based emissions. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Old corrugated containers with low recyclability were used as raw materials to synthesize a series of aerogels with varying cellulose concentrations in NaOH/urea solution via a freeze-drying process. The resulting aerogels had a rich porous structure with specific surface areas in the range of 132.72-245.19 m 2 .g -1 and mesopore volumes in the range of 0.73-1.53 cm 3 .g -1 , and were tested for CO 2 sorption at ambient temperature and pressure, displaying excellent CO 2 adsorption capacities in the range of 1.96-11.78 mmol.g -1 . Furthermore, the CO 2 /N 2 selectivity of aerogels decreased with decreasing specific surface area, which was mainly caused by the decrease in CO 2 capture. In addition, the CO 2 sorption capacity of the sample with 2% cellulose content, CA-2, exceeded the values reported so far for many other sorbents with higher specific surface areas, and showed reasonable cyclic stability for CO 2 capture. Therefore, this adsorbent represents an attractive prospect for CO 2 uptake at room temperature., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Sweden is one of the largest exporters of pulp and paper products in the world. It follows that huge quantities of sludge rich in carbonaceous organic material and containing heavy metals are generated. This paper carried out a comparative environmental analysis of three different technologies, which can be adopted to produce biochar and recover energy from the biosludge, using landfilling as the reference case. These three thermochemical biosludge management systems—using incineration, pyrolysis, and hydrothermal carbonization (HTC)—were modeled using life cycle assessment (LCA). Heat generated in the incineration process (System A) was considered to be for captive consumption within the kraft pulp mills. It was assumed that the biochars—pyrochar and hydrochar—produced from pyrolysis (System B) and HTC (System C), respectively, were added to the forest soils. The LCA results show that all the alternative systems considerably improve the environmental performance of biosludge management, relative to landfilling. For all systems, there are net reductions in greenhouse gas emissions (–0.89, –1.43, and –1.13 tonnes CO2‐equivalent per tonne dry matter biosludge in Systems A, B, and C, respectively). System B resulted in the lowest potential eutrophication and terrestrial ecotoxicity impacts, whereas System C had the least acidification potential. The results of this analysis show that, from an environmental point of view, biochar soil amendment as an alternative method for handling pulp and paper mill biosludge is preferable to energy recovery. However, an optimal biochar system needs to factor in the social and economic contexts as well. [ABSTRACT FROM AUTHOR]

The economic feasibility of retrofitting an amine based post-combustion CO 2 capture process to an existing Kraft pulp mill and an existing integrated pulp and board mill has been assessed. This study builds on the technical assessment of the energy performance of the mills when retrofitting a post-combustion CO 2 capture process by Onarheim et al. (2017). Between 75 to 100% of the CO 2 emissions from the pulp and paper industry originate from the combustion of biomass. If the raw material is sourced sustainably, these emissions are categorized as carbon neutral. Applying sustainably managed biomass in the pulp and paper processes and capturing the resulting CO 2 for permanent storage enables the industry to go carbon negative. In this study, the economic impact of retrofitting CO 2 capture from the flue gases of the recovery boiler, the multi-fuel boiler and the lime kiln were assessed. The levelized cost of pulp and the cost of CO 2 avoided were evaluated based on six different scenarios varying the CO 2 tax, incentives for renewable electricity production, with and without recognizing biogenic CO 2 emissions as neutral (exempting CO 2 emissions from tax or not), and rewarding captured and permanently stored CO 2 with negative emissions credit. Results show that the pulp and paper industry has a potential for realizing feasible implementation of large-scale industrial Bio-CCS. For cases where 60–90% of total site CO 2 emissions are captured, the cost of avoided CO 2 amounts to 52–66 €/t for the Kraft pulp mill and 71–89 €/t for the integrated pulp and board mill. The cost of avoided CO 2 , and thus the realization of Bio-CCS in the pulp and paper industry, is strongly dependent on prevailing policy frameworks such as the EU ETS. In order to reach a levelized cost of pulp similar to the reference mill without CO 2 capture, a negative CO 2 emission credit of 60–70 €/t CO 2 for the Kraft pulp mill and 70–80 €/t CO 2 for the integrated pulp and board mill will be required. As long as biogenic CO 2 emissions that are captured and permanently stored are not recognized as negative and rewarded accordingly there is no economic incentive for the owners of pulp and paper mills to implement CCS. The only way to get the pulp and paper industry to implement and deploy Bio-CCS will need the support of the decision-makers in promoting the right policy framework and regulations to encourage the investment such as strong incentives for negative emissions which are bankable during the long term operation of the mills. [ABSTRACT FROM AUTHOR]

Using an extended full-cycle carbon model from the Faustmann framework, which allows for management strategies of several uses concurrently implemented in the same area of forest, this paper investigates the selection of management objectives that are beneficial and optimal for forest plantations in Vietnam. Three scenarios are considered: Scenario 1 investigates the management objective of maximizing the land economic value (LEV) of timber as a single production. Scenario 2 investigates the joint production of timber and bioenergy sources. Scenario 3 analyzes the joint production of timber, bioenergy production, and carbon sequestration. The findings reveal that if growers pursue a timber management objective (Scenario 1), the farming business only provides considerable benefits under the government-subsidized credit scheme of 8.4%. For a higher non-subsidized interest rate of 15.24% of commercial banks, such gains reduce substantially and become negative value under the mean interest rate of 19.08% of private credit sources. Altering the management objective to a joint production of timber and raw bioenergy production (Scenario 2) will boost the LEV by a moderate level, but at the expense of timber production and thus carbon stock. However, the reduction tendency of timber and carbon balance is not substantial due mainly to the relatively small proportion of bioenergy production compared to timber production; therefore, decision-making frameworks targeting carbon uptake may be capable of incorporating such levels of confliction. Further internalizing the carbon value of the forest into management objectives generally leads to a longer rotation length, thus improving both carbon sequestration and income gains. Shifting the current timber-dominant management objective to a joint production of timber and bioenergy sources, or, alternatively, a joint production of timber, bioenergy production, and carbon sequestration when the carbon market is emerging, is a good alternative strategy for forest management in Vietnam., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The performance of an amine-based post-combustion CO 2 capture and storage (CCS) process in an existing Kraft pulp mill and an existing pulp and board mill was assessed. The pulp and paper industry is an energy-intensive industry, with significant amounts of CO 2 emitted onsite. The majority of this CO 2 originates from the combustion of biomass, which renders it carbon neutral if the biomass used by the industry is grown and harvested in a sustainable manner. If the CO 2 emissions from the pulp and paper industry were to be captured and permanently stored, then this could make the industry a potential carbon sink. In this evaluation, different configurations of capturing CO 2 from the flue gases of the recovery boiler, the multi-fuel boiler and the lime kiln were assessed. For a stand-alone Kraft pulp mill, the excess steam available is sufficient to cover the demand from the CO 2 capture plant. For an integrated pulp and board mill, there is less excess steam available for the CO 2 capture plant and an auxiliary boiler may be required. The retrofit of a post-combustion CO 2 capture plant into an existing pulp mill increases the steam demand by 1–8 GJ/air dried tonne (adt) pulp, depending on the volume of the flue gas treated. This translates to a reduction in the amount of electricity exported to the grid by 0.1–1.0 MWh/adt pulp for a stand-alone Kraft pulp mill, and by 0.1–0.5 MWh/adt pulp for an integrated pulp and board mill. The total potential for negative CO 2 emissions amounts to just under 2.0 Mt CO 2 /a both for the market pulp mill and for the integrated pulp and board mill. [ABSTRACT FROM AUTHOR]

• The hygroscopic property of paper fiber is used to prepare a bifunctional catalyst. • The impregnation time for preparing the hollow microtubular Ni-MgO-CaO is 1 min. • 94.1 % of hydrogen is stably produced on 5Ni-10MgO-CaO from biogas for 50 cycles. • Only 37.1 % loss of the sorption-enhanced effect is shown during the entire cycle. Sorption-enhanced steam reforming (SESR) process is a promising technology aiming at the production of high purity hydrogen with CO 2 capture. The key to the success of this process is the availability of high-performance bifunctional catalysts. Herein, we develop a hollow microtubular Ni-MgO-CaO bifunctional catalyst with paper fiber as template. Due to the strong hygroscopic properties of paper fibers, it provides a method for the rapid synthesis of catalysts with design components by adsorbing solution. The characterizations indicate that the impregnation time (1 min vs 24 h) has no effect on the structural properties of Ni-MgO-CaO bifunctional catalysts. MgO as an inert spacer can weaken the sintering of CaO to ensure a stable CO 2 uptake. Moreover, the agglomeration of Ni particles is inhibited by the MgO coating on their surface. 5Ni-10MgO-CaO as the best performing catalyst displays high stability for the SESR of biogas (SESRB) reaction, during which 94.1 % purity of hydrogen with a 95.2 % conversion of CH 4 is stably produced and only 37.1 % decrease of sorption-enhanced effect is observed in 50 SESRB-calcination cycles. [ABSTRACT FROM AUTHOR]

In order to meet the IPCC recommendation for an 80% cut in CO 2 emissions by 2050, industries will be required to drastically reduce their emissions. To meet these targets, technologies such as carbon capture and storage (CCS) must be part of the economic set of decarbonisation options for industry. A systematic review of the literature has been carried out on four of the largest industrial sectors (the iron and steel industry, the cement industry, the petroleum refining industry and the pulp and paper industry) as well as selected high-purity sources of CO 2 from other industries to assess the applicability of different CCS technologies. Costing data have been gathered, and for the cement, iron and steel and refining industries, these data are used in a model to project costs per tonne of CO 2 avoided over the time period extending from first deployment until 2050. A sensitivity analysis was carried out on the model to assess which variables had the greatest impact on the overall cost of wide-scale CCS deployment for future better targeting of cost reduction measures. The factors found to have the greatest overall impact were the initial cost of CCS at the start of deployment and the start date at which large scale deployment is started, whilst a slower initial deployment rate after the start date also leads to significantly increased costs. [ABSTRACT FROM AUTHOR]

Urbanisation has emerged as a formidable challenge for urban policymakers, reaching unparalleled heights and unsettling the ecological equilibrium of the cities. Urban areas now grapple with many issues encompassing climate change, resource depletion, population surges and increased pollution levels. Many planned cities have planted trees and other vegetation within the urban sectors to enhance air quality, mitigate climate effects and provide valuable ecosystem services. This study assessed tree species diversity and their potential for carbon sequestration in Panjab University Campus, Chandigarh. We established 188 plots, each comprising randomly selected quadrats measuring 10 m × 10 m, encompassing areas with varying levels of vegetation, ranging from low to moderate and high density. We used four different allometric equations to estimate tree biomass and carbon stock. Our findings revealed that 92 tree species belong to 72 genera and 35 families, with a total tree density of 975 ha -1 . The total CO 2 sequestration in form of carbon stock was 18,769.46 Mg C ha -1 , with Manilkara hexandra (1239.20 Mg C ha -1 ), Ficus benghalensis (1072.24 Mg C ha -1 ), Kigelia pinnata (989.89 Mg C ha -1 ) and Lagerstroemia floribunda (716.88 Mg C ha -1 ) being the top contributors. Specifically, the equation of Chave et al. (2005) without tree height yielded the highest biomass and carbon stock estimates than other equations. The present study underscores the vital role of trees on the campus as potent carbon reservoirs meet to maintain an aesthetic sense for biotic components and alleviate rising levels of CO 2 in the atmospheric environment. By emphasising the role of urban trees as potent carbon reservoirs, the study underscores the importance of integrating green infrastructure into urban planning strategies. Furthermore, it offers valuable guidance for urban planners. It suggests that strategic tree planting and maintenance can enhance green spaces, regulate temperatures and ultimately support regional and global climate change mitigation goals. Incorporating these findings into urban planning processes can aid policymakers in developing resilient, ecologically sustainable cities worldwide., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

As the urgency to address climate change intensifies, the exploration of sustainable negative emission technologies becomes imperative. Enhanced weathering (EW) represents an approach by leveraging the natural process of rock weathering to sequester atmospheric carbon dioxide (CO 2 ) in agricultural lands. This review synthesizes current research on EW, focusing on its mechanisms, influencing factors, and pathways for successful integration into agricultural practices. It evaluates key factors such as material suitability, particle size, application rates, soil properties, and climate, which are crucial for optimizing EW's efficacy. The study highlights the multifaceted benefits of EW, including soil fertility improvement, pH regulation, and enhanced water retention, which collectively contribute to increased agricultural productivity and climate change mitigation. Furthermore, the review introduces Monitoring, Reporting, and Verification (MRV) and Carbon Dioxide Removal (CDR) verification frameworks as essential components for assessing and enhancing EW's effectiveness and credibility. By examining the current state of research and proposing avenues for future investigation, this review aims to deepen the understanding of EW's role in sustainable agriculture and climate change mitigation strategies., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

As the world's largest carbon sink, the oceans are essential to achieving the 1.5 °C target. Marine ecosystems play a crucial role in the "sink enhancement" process. A deeper comprehension of research trends, hotspots, and the boundaries of ocean carbon sinks is necessary for a more effective response to climate change. To this end, academic literature in the field of ocean carbon sinks was investigated and analyzed using the core database of the Web of Science. The results show that (1) The ocean carbon sink is a global study. The number of literatures in the field of ocean carbon sinks is growing, and the USA and China are the main leaders, with the USA accounting for 31.19% of the global publications and China accounting for 26.57% of the global publications, and the environmental science discipline is the most popular in this field. (2) Keyword burst detection shows that the keywords "sink, sensitivity, land, dynamics, and seagrass" appear earliest and have high burst intensity, which are the hot spots of research in this field; the keyword clustering shows that the global ocean carbon sinks research mainly focuses on three themes: (i) carbon cycle and climate change; (ii) carbon sinks estimation models and techniques; and (iii) carbon sinks capacity and ocean biological carbon sequestration in different seas. Finally, targeted research recommendations are proposed to further match the ocean carbon sink research., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In this work, a techno-economic assessment of carbon dioxide capture from limekiln flue gas of a pulp and paper mill (Mill A) and a linerboard mill (Mill B) using a Monoethanolamine (MEA) absorption desorption process was carried out. We coupled the ASPEN Plus simulator with a derivative-free optimization (DFO) tool to identify the optimal configuration for minimizing the total capture cost. The capture costs were calculated using CAPCOST, a modular program for equipment cost estimation, and appropriate coefficients. Eight degrees of freedom, the direct contact cooler stages, the absorber stages, the stripper stages, the solvent lean loading, the solvent weight concentration, the stripper inlet temperature, the flue gas inlet temperature, and the amount of CO2 captured, were selected for process and flowsheet optimization. Additionally, we evaluated the effect of steam integration and Sect. 45Q of the existing federal tax credit for carbon capture and sequestration on CO2 capture costs. The total capture costs per tonne of CO2 were $64.9 for Mill A and $69.7 for Mill B. When steam integration and Sect. 45Q are considered, the costs dropped to − $2.5 and $2.6 for Mill A and Mill B, respectively. The sensitivity of CO2 capture cost to changes in the inlet flue gas flowrate, flue gas CO2 mol%, and the electricity and MEA prices were investigated. The sensitivity analysis results revealed that the capture costs vary from − $5.9 to $5.9 per tonne of CO2 captured. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A scalable papermaking process was employed herein to manufacture cellulosic papers from native and phosphorylated cellulose microfibers (referred to as CMF and PCMF, respectively) impregnated with polyethyleneimine (PEI) for Direct Air Capture (DAC) applications. These papers were analyzed in terms of their physico-chemical properties using several techniques. The impact of PEI content on desorbing the co-adsorbed H 2 O and CO 2 from the air, as well as on the anisotropic microporous network, was explicitly analyzed. The results indicated that phosphorylation promotes the uptake of both CO 2 and H 2 O in the corresponding neat and PEI-loaded papers, reaching a superior CO 2 adsorption capacity of ∼0.7–0.9 mmol.g−1 for PCMF papers versus 0.07–0.3 mmol.g−1 for CMF papers. Furthermore, the CMF and PCMF papers exhibited H 2 O adsorption capacities in the range of 1.5–1.8 mmol.g−1 and 2.2–3.8 mmol.g−1, respectively. This work further highlights the combined role of phosphorylation and favorable PEI impregnation in tuning the cellulose CO 2 adsorption properties under humid conditions, facilitating the rapid release of the adsorbed CO 2 under mid conditions. [Display omitted] • Manufacturing of scalable solid cellulosic papers with amine functionalities and enhanced carbon capture. • Microstructural and chemical characterization of amine functionalized paper with various amine ratios. • Valorization of Alfa biomass in Carbon capture applications. • The combined role of phosphorylation and PEI impregnation in tuning the H 2 O and CO 2 co-adsorption properties. [ABSTRACT FROM AUTHOR]

Mangroves play a globally significant role in carbon capture and storage, known as blue carbon ecosystems. Yet, there are fundamental biogeochemical processes of mangrove blue carbon formation that are inadequately understood, such as the mechanisms by which mangrove afforestation regulates the microbial-driven transfer of carbon from leaf to below-ground blue carbon pool. In this study, we addressed this knowledge gap by investigating: (1) the mangrove leaf characteristics using state-of-the-art FT-ICR-MS; (2) the microbial biomass and their transformation patterns of assimilated plant-carbon; and (3) the degradation potentials of plant-derived carbon in soils of an introduced (Sonneratia apetala) and a native mangrove (Kandelia obovata). We found that biogeochemical cycling took entirely different pathways for S. apetala and K. obovata. Blue carbon accumulation and the proportion of plant-carbon for native mangroves were high, with microbes (dominated by K-strategists) allocating the assimilated-carbon to starch and sucrose metabolism. Conversely, microbes with S. apetala adopted an r-strategy and increased protein- and nucleotide-biosynthetic potentials. These divergent biogeochemical pathways were related to leaf characteristics, with S. apetala leaves characterized by lower molecular-weight, C:N ratio, and lignin content than K. obovata. Moreover, anaerobic-degradation potentials for lignin were high in old-aged soils, but the overall degradation potentials of plant carbon were age-independent, explaining that S. apetala age had no significant influences on the contribution of plant-carbon to blue carbon. We propose that for introduced mangroves, newly fallen leaves release nutrient-rich organic matter that favors growth of r-strategists, which rapidly consume carbon to fuel growth, increasing the proportion of microbial-carbon to blue carbon. In contrast, lignin-rich native mangrove leaves shape K-strategist-dominated microbial communities, which grow slowly and store assimilated-carbon in cells, ultimately promoting the contribution of plant-carbon to the remarkable accumulation of blue carbon. Our study provides new insights into the molecular mechanisms of microbial community responses during reforestation in mangrove ecosystems., (© 2023 John Wiley & Sons Ltd.)

[Display omitted] • Mixed sludge from pulp and paper mill wastewater treatment was treated with HTC. • HTC enhanced energy recovery in hydrochars having 37% increased heating value. • No significant sludge dewaterability improvement was observed after HTC. • HTC increased filtrate organics content and volumetric methane production potential. • Mixed sludge hydrochars are potential for carbon sequestration. The pulp and paper industry's mixed sludge represents waste streams with few other means of disposal than incineration. Hydrothermal carbonization (HTC) could be advantageous for the sludge refinement into value-added products, thus complementing the concept of pulp and paper mills as biorefineries. Laboratory HTC was performed on mixed sludge (at 32% and 15% total solids) at temperatures of 210–250 °C for 30 or 120 min, and the characteristics of the HTC products were evaluated for their potential for energy, carbon, and nutrient recovery. The energy content increased from 14.9 MJ/kg in the mixed sludge up to 20.5 MJ/kg in the hydrochars. The produced filtrates had 12–15-fold higher COD and 3–5-fold higher volumetric methane production than untreated sludge filtrates, even though the methane yield against g-COD was lower. The increased value of the hydrochars in terms of energy content and carbon sequestration potential promote HTC deployment in sludge treatment and upgrading. [ABSTRACT FROM AUTHOR]

Blue carbon sinks (mangroves, saltmarshes, and seagrasses) are considered an effective nature-based approach for climate change mitigation. Despite growing interest, a systematic review of this topic is still scarce. This study evaluated 1348 blue carbon sink-related articles from 1990 to 2020 using bibliometric technology. The results from total of 85 countries, 1538 institutions, and 4492 authors indicated that blue carbon sink research shows the characteristics of rapid growth. The most active country, institution, and author were USA, Chinese Academy of Sciences, and Duarte C.M., respectively. Relatively close academic collaboration has formed in blue carbon science. Environmental Sciences was the most popular category with 590 papers. The percentages of articles related to mangroves, saltmarshes, and seagrasses were 63.87%, 40.36%, and 40.65%, respectively. Mangrove carbon sinks are the most popular topic, and stable isotope and remote sensing are the most researched technologies for mapping and quantifying blue carbon sinks. The threats to blue carbon sinks are complex and distinctive. Restoration, conservation, and management of blue carbon ecosystems aimed to improve their carbon sink capacity are becoming hot issues and should be further investigated in the future. These findings provide a scientific roadmap for further research in this field and will enable stakeholders to identify the research trend., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

• Black liquor gasification was coupled with calcium looping. • Calcium looping for CO 2 capture and H 2 production was compared. • CO 2 capture route (39 €/t) was less expensive than H 2 production route (48.8 €/t). • CO 2 avoided cost was highly dependent on capital cost of black liquor gasification. • Export of H 2 had the lowest CO 2 avoided cost among black liquor gasification cases. Although considered one of the major energy-intensive industries (EIIs), the pulp and paper industry has also the potential for energy production from an industrial waste, black liquor. This study proposes black liquor gasification (BLG) coupled with calcium looping (CaL) as a CO 2 capture route for the pulp and paper industry. BLG with H 2 production (BLG-CaL-H 2), BLG with gas turbine combined cycle (BLG-CaL-GT) or with solid oxide fuel cell (BLG-CaL-SOFC) were considered. The dependence of carbon capture and storage (CCS) cost on the natural gas, limestone, electricity imported and H 2 sale prices aside the expenditures related with BLG-CaL were evaluated. The CCS route, based on CaL retrofitted to the pulp and paper plant, was found to have a lower cost of CO 2 avoided (39.0 €/tCO 2) when compared with BLG-CaL (48.8–57.1 €/tCO 2). Between the BLG-CaL scenarios, BLG-CaL-H 2 presented the lowest cost of CO 2 avoided (48.8 €/tCO 2) but the highest energy penalty. Based on the thermodynamic performance, it was shown that CaL retrofit and BLG-CaL-SOFC presented the best overall performance, turning the electricity importer reference plant into electricity exporter. The economic sensitivity showed that the capital requirement of BLG-CaL has a strong effect on the cost of CO 2 avoided for all alternatives. The H 2 production is also strongly affected by the H 2 sale price while BLG-CaL-SOFC and BLG-CaL-GT are strongly dependent on natural gas price. [ABSTRACT FROM AUTHOR]

Abstract: Carbon capture and storage (CCS) is one of a suite of technology options that might play a significant role in reducing greenhouse gas emissions. However, outside of traditional enhanced oil and gas recovery operations with a well established business model, CCS project deployments are struggling with adoption of a federal or international climate policy driver appearing unlikely for the foreseeable future. As part of a feasibility study for an industrial CCS project at the Boise White Paper mill in Washington State, a business model and CCS system design was developed that provided financial surety for the project developers while recognizing that uncertainty in revenue forecasts for CO2 storage would persist for the foreseeable future. Key to the business model was installation of a new 37MWe biomass-fueled power island at the plant that would replace antiquated boilers and that could still supply the necessary steam to run pulp and paper production operations when capturing CO2 emissions under favorable market conditions for monetizing CO2 storage credits. Under unfavorable market conditions, CO2 capture would be suspended and excess power generated from the plant would reduce external electrical energy purchases required for paper mill operations. The net CO2 reduction for the project versus current operations is 1.0MMT of CO2 per year with the CCS system online, and 139ktons per year with the CCS system offline due to reduced natural gas co-firing. So, both operational modes offered a significant net reduction in CO2 emissions. Based on assumptions regarding electricity and natural gas pricing, and CO2 storage revenue generated through an open market mechanism priced at $15 per metric ton CO2, the payback period for the project capturing 0.5MMT/yr (62% of total CO2 production) was estimated at 6.7 years versus 7.4 years with the CCS system offline. Geologic storage was evaluated in the deep flood basalt formations that dominate the storage capacity in Eastern Washington. Sub-basalt sediments were also examined at the site to provide alternative or supplemental storage capacity in the event that storage in the basalt sequences did not prove technically or economically feasible. [Copyright &y& Elsevier]

Land-based CO 2 removal demands changes in management or new suitable areas to sustainably grow additional biomass without reducing food supply or damaging natural ecosystems. The soil organic carbon (SOC) sequestration pathway is thought to transfer atmospheric CO 2 into a land unit, through plants, plant residues and other organic solids stored as part of the soil organic matter. No previous study explored SOC sequestration potentials on global marginal land. Here we integrated, into a generalizable modelling framework, the mapping of a set of biophysical (climatic and edaphic) and land conservation constraints to (i) identify suitable matches (i.e. biophysically possible combinations) of target areas with plant species, and (ii) to quantify contributions of pairing to long-term SOC sequestration (2020-2100). The proposed framework represents a refinement to previous mapping exercises, which seldom consider biophysical constraints, soil erosion, plant species tolerances to pedoclimatic conditions, and world protected areas. The approach was tested on marginal lands featuring SOC-deficient stocks (≤ 50 Mg SOC ha -1 to 30 cm depth) at 30 arc-sec resolution, consolidated into world regions × global ecological zones based on geo-localised products. The framework was shown to enable better-informed decision-making on interventions at large geographical scales, revealing biophysically realistic options, while management should be determined locally., (© 2022. The Author(s).)

To limit climate warming to 2°C above preindustrial levels, most economic sectors will need a rapid transformation toward a net zero emission of CO 2 . Tuna fisheries is a key food production sector that burns fossil fuel to operate but also reduces the deadfall of large-bodied fish so the capacity of this natural carbon pump to deep sea. Yet, the carbon balance of tuna populations, so the net difference between CO 2 emission due to industrial exploitation and CO 2 sequestration by fish deadfall after natural mortality, is still unknown. Here, by considering the dynamics of two main contrasting tuna species (Katsuwonus pelamis and Thunnus obesus) across the Pacific since the 1980s, we show that most tuna populations became CO 2 sources instead of remaining natural sinks. Without considering the supply chain, the main factors associated with this shift are exploitation rate, transshipment intensity, fuel consumption, and climate change. Our study urges for a better global ocean stewardship, by curbing subsidies and limiting transshipment in remote international waters, to quickly rebuild most pelagic fish stocks above their target management reference points and reactivate a neglected carbon pump toward the deep sea as an additional Nature Climate Solution in our portfolio. Even if this potential carbon sequestration by surface unit may appear low compared to that of coastal ecosystems or tropical forests, the ocean covers a vast area and the sinking biomass of dead vertebrates can sequester carbon for around 1000 years in the deep sea. We also highlight the multiple co-benefits and trade-offs from engaging the industrial fisheries sector with carbon neutrality., (© 2023 The Authors. Global Change Biology published by John Wiley & Sons Ltd.)

In this paper an approach for analysing the potential for implementation of different technology pathways for the European pulp and paper industry (PPI) is presented. The approach is based on detailed technical research and aggregates the knowledge from previous studies to incorporate the whole European PPI. Thus, the potential for different technology pathways can be estimated on a European level whilst still considering important characteristics of individual mills. The usefulness of the approach was exemplified by applying it to a case study of the potential for introduction of carbon capture and storage (CCS) within the European PPI. The results from the case study show that for the European PPI, CCS has an up-hill road in order to be a viable, large scale alternative for reduction of CO2 emissions. If CCS is to be introduced in large scale within the European PPI, large biomass-based point sources of CO2 emissions need to be included when planning for CCS infrastructure and also the infrastructure needs to be built out for clusters emitting <20 MtCO2/yr. [ABSTRACT FROM AUTHOR]

Carbon dioxide mineral carbonisation is a means to achieve permanent carbon dioxide storage, this paper to solid waste materials as the main raw material to prepare fly ash-based carbon dioxide storage materials. Through the design of carbon dioxide adsorption experimental setup to study the main factors affecting the adsorption capacity of the fly ash-based storage materials, the experimental results show that, the fly ash mass fraction decreased from 90 to 10%, the water-cement ratio increased from 0.4 to 0.8 when the CO2 adsorption of fly ash-based materials increased by 82% and 30%, respectively. The effect of strong alkali on CO2 adsorption capacity was also investigated in this paper, and the results showed that the CO2 adsorption of the fly ash-based material sample with 10 ml NaOH added increased by 197% compared with that of the sample with 5 ml NaOH added, whereas the adsorption amount was reduced by 85% when 25 ml NaOH was added instead, which was attributed to the accelerated hydration process of the material due to the excessive alkalinity that consumed the calcium and magnesium ions in the material, and at the same time the production of hydration products hindered the transport of CO2 within the material, which led to a decrease in CO2 adsorption. [ABSTRACT FROM AUTHOR]

Pulp and paper is considered to be the fourth most energy-intensive industry (EII) worldwide. However, as most of the CO 2 emissions are of biomass origin, this sector has the potential to become a carbon-negative industry. This study proposes a new concept for conversion of the pulp and paper industry to carbon negative that relies on the inherent CO 2 capture capability of the Kraft process. The techno-economic performance of the proposed carbon-negative system, based on calcium looping (CaL) retrofitted to a pulp and paper plant, was evaluated. The effect of CaL design specifications and cost assumptions on the thermodynamic and economic performance were evaluated. Under the initial design assumptions, the reference pulp and paper plant was shown to turn from electricity importer to electricity exporter with the cost of CO 2 avoided equal to 39.0 €/tCO 2. The parametric study showed that an increase in the fresh limestone make-up rate resulted in a linear increase of the specific primary energy consumption for CO 2 avoided (SPECCA) and a reduction in the amount of electricity exported to the electric grid. This translates into an increase in the price of pulp and newsprint, and the cost of CO 2 avoided. This study has also demonstrated that the pulp and paper industry has high potential to become carbon negative. It has been shown that carbon capture and storage would become economically viable in this industry if the negative CO 2 emissions are recognised and a negative CO 2 emissions credit of at least 41.8 €/tCO 2 is implemented. • Concept of the Kraft process with inherent CO 2 capture. • Calcium looping for CO 2 capture is integrated in the lime cycle. • Reference pulp and paper plant turns from importer to exporter of electricity. • Pulp and paper industry has a high potential to become carbon negative. • Economic feasibility needs the inclusion of biogenic emissions in emission trading. [ABSTRACT FROM AUTHOR]