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Abstract: Manufacturing and trade of wood pellets in the United States (US) has seen an exponential growth in the last few years, triggered by its potential utilization in applications typically dominated by fossil fuels, such as heat, power, and combined cycle generation. This combination holds the promise of delivering a high density, high heat value fuel, making it a better substitute for coal and other fossil fuels. This combined process exists only at pilot-plant levels. Scale-up of the technology and feasibility of such projects remain largely unexplored. This research developed a techno-economic model for the production of torrefied wood pellets, considering critical production parameters, and evaluating sensitivity to changes in CAPEX (Capital Expenditure), biomass delivered costs, labor, and energy consumption of a facility, evaluated through a case-study. Results indicated that biomass delivered costs and depreciation are the most significant factors influencing production with CAPEX being the most sensitive variable due to high investments in torrefaction reactors. The selection of different torrefaction technologies, and adequate binders, may represent a major improvement in the feasibility of a project by reducing capital costs drastically. Back-calculated price for torrefied wood pellets is $261/metric ton (100,000 metric tons/year facility), and delivered price may reach $282/metric ton, a similar cost compared to regular pellets. Preliminary analysis of carbon credits as additional income may considerably increase the likeability of the business, and further enhance profitability. [Copyright &y& Elsevier]

Highlights • Sweet sorghum bagasse has much of free sugars after squeezing juice. • Single stage autohydrolysis causes degradation of free sugars. • Two-stage autohydrolysis pretreat bagasse minimizing free sugars degradation. • Two-stage autohydrolysis is effective for sugar recovery from Sweet sorghum bagasse. Abstract Modified autohydrolysis combined with mechanical refining has been suggested to recover free sugars from sweet sorghum bagasse and facilitates enzyme access to cellulose in bagasse for enhancing its conversion to fermentable sugars. The amount of total available sugars in sweet sorghum bagasse was found to be 76.1% and this value was used to evaluate the efficiency of the process suggested. Total sugar recovery was achieved up to 68.1% through the single-stage autohydrolysis at 170 °C for 60 min, followed by mechanical refining and enzymatic hydrolysis; however, the sugar recovery through partial degradation of free sugars induced by high-temperature autohydrolysis was lower than expected. A modified two-stage autohydrolysis was suggested to prevent sugar degradation and the total sugar recovery using this process reached 83.9% of total available sugars in sweet sorghum bagasse. [ABSTRACT FROM AUTHOR]

The cradle-to-grave environmental impacts of thermochemical ethanol from loblolly pine, eucalyptus, unmanaged hardwoods, forest residues, and switchgrass biomass feedstocks were determined and compared to gasoline. The Tool for the Reduction and Assessment of Chemical and Other Impacts (TRACI) method was implemented in SimaPro 7.3 to calculate midpoint environmental impacts. Two normalization value sets were used and weighting was performed to produce a single environmental score. Greenhouse gas (GHG) emission reductions of cellulosic ethanol as compared to gasoline were 65%–77%, depending on the biomass feedstock, qualifying these biofuels as cellulosic ethanol under the Renewable Fuel Standards (RFS2). Effects of direct land-use change were significant (~ 18%) and could increase the GHG emissions for switchgrass derived ethanol above the federal GHG reduction thresholds for cellulosic ethanol. The production and use of cellulosic ethanol reduced fossil fuel consumption by between 95% and 97% and by 81% for forest and switchgrass derived ethanol, respectively. Cellulosic ethanol, however, did not reduce all environmental impact categories (e.g., eutrophication, ozone depletion respiratory effects, acidification, and smog) compared to gasoline. The fuel scenario ranking from lowest impact to highest impact consistently remained the same for GHG emissions, fossil fuel use, and the two single weight score analysis methods and was, in ascending order, forest residues with no forest establishment burdens, forest residues with forest establishment burdens, natural hardwood, pine, switchgrass, and finally gasoline. The GHG emission reductions from the use of cellulosic ethanol at the renewable fuel standards mandated production volume of 16 billion gallons of cellulosic ethanol per year by 2020 would result in 9–10 billion metric tonnes of GHG emissions avoided. [ABSTRACT FROM AUTHOR]

Abstract: The present work targeted the understanding of the influence of nine different hardwood species as feedstock on ethanol production yield and costs. It was found that the minimum ethanol revenue (MER) ($ per gallon to the producer) to achieve a 12% internal rate of return (IRR) on invested capital was smaller for low lignin content samples and the influence of species characteristics remained restricted to high residual lignin content. We show that if the pretreatment being applied to the feedstock targets or is limited to low lignin removal, one can expect the species to have a significant impact on overall economics, playing important role to project success. This study also showed a variation of up to 40% in relative MER among hardwood species, where maple, globulus and sweet gum varied the least. Sensitivity analysis showed ethanol yield per ton of feedstock had the largest influence in MER, followed by CAPEX. [Copyright &y& Elsevier]

Biomass, as a raw material, has been identified as a crucial component of decarbonization strategies to mitigate climate change. Decisions on which biomass should be targeted for different purposes are dependent on variables such as availability, chemical composition, and sustainability. Consumer perception often positions non-wood sources, such as bamboo, as environmentally preferable feedstocks for fiber-based product production. Yet, this perceived environmental benefit lacks robust scientific substantiation and standardized methodologies. This study addresses this gap by conducting a cradle-to-gate life cycle assessment (LCA) of twelve biomass production systems encompassing tree plantations, dedicated crops, and agricultural residues for energy and bioproducts manufacture. The evaluated feedstocks include southern softwood, wheat straw, rice straw, rice husk, hemp hurd, sugarcane bagasse, switchgrass, biomass sorghum (United States), eucalyptus (Brazil), bamboo (China), and northern softwood (Canada). Incorporating a critical yet often overlooked factor, this LCA integrates the potential soil organic carbon sequestration (SOC) via below-ground biomass for each biomass type. This consideration significantly alters the estimated carbon intensity per ton of feedstock, potentially reshaping sustainability perceptions as certain systems emerge as carbon sinks. From a cradle-to-farm gate perspective, the assessed global warming potential for biomass production spans 12–245 kg CO 2 eq per oven-dry ton (ODt), factoring only anthropogenic emissions. However, when accounting for SOC sequestration, the range shifts to −170 to 228 kg CO 2 eq per ODt, highlighting the potential role of biomass to act as carbon sink systems. By illuminating the dynamic influence of SOC sequestration, this study contributes to a more comprehensive understanding of biomass-related carbon emissions, shedding light on pathways to mitigate environmental impact. [Display omitted] • Soil carbon shifts biomass assessment. • Holistic analysis integrates soil carbon, displaying biomass potential. • Diverse biomasses offer net-zero path, fueling sustainability. [ABSTRACT FROM AUTHOR]

This work evaluates wheat straw, switchgrass, and hemp hurd as potential alternatives for producing dissolving pulp using sulfur dioxide (SO 2)-ethanol-water (SEW) pulping. The SEW process is described in detail for wheat straw, and the best pulping conditions for this feedstock were 130 °C, 4 h, and 10% SO 2 concentration, comprised in a sulfur-ethanol-water ratio of 10-45-45. This resulted in a viscose-grade pulp with 93% α-cellulose, 2.0% hemicelluloses, <0.1% lignin, 0.2% ash content, and a viscosity of 4.7 cP. The best pulping conditions for wheat straw were applied to switchgrass and hemp hurd. Wheat straw and switchgrass had similar pulp quality, while hemp hurd pulp had a higher hemicellulose content and lower viscosity. This work suggests that non-wood feedstocks such as wheat straw and switchgrass can be promising alternatives for dissolving pulp production, which can help reduce the pressure on the textile industry to increase the use of natural fibers and mitigate the environmental impact of non-biodegradable synthetic fibers. [Display omitted] • Wheat straw, switchgrass, and hemp hurd were evaluated for dissolving pulp production. • Viscose-grade dissolving Pulp can be obtained from non-wood feedstocks. • SEW pulping can provide dissolving grade pulp. • Non-wood sources are a promising alternative for natural textile fibers. • Dissolving pulp quality changes based on the nature of the non-wood feedstock. [ABSTRACT FROM AUTHOR]

The need to decarbonize and reduce the impact of human activities is opening the window for new bioproducts. The industry of bioplastics has grown exponentially in the past years, and its production is expected to triple by 2026. Different bioplastics are currently produced, but bio-polyethylene constitute an interesting opportunity since its fossil counterpart is one of the most used materials worldwide, and its precursor, ethylene, is one of the highest contributors to GHG emissions in the chemical industry. The true environmental impact of this bio-based plastic remains under controversial discussions due to a wide distribution of environmental indicators values found in the literature for this material. We aim to thoroughly evaluate the environmental impact of bio-polyethylene made from sugarcane across the different production stages through a life cycle analysis. Our goal is also to assess unintended consequences (consequential effects) of producing it. It was determined that land-use change represents the main aspect affecting the environmental sustainability of bio-polyethylene. From an attributional point of view, this bioplastic could present lower carbon footprints than fossil polyethylene if no deforestation occurs. From a consequential standpoint, indirect deforestation as a response to producing more bioplastic could negatively impact the environmental profile of this material. Policies restricting deforestation are required to ensure that bio-polyethylene can constitute an alternative to reduce the carbon footprint of products in both scenarios. We expect this work to provide a robust evaluation to understand the environmental impact of bio-polyethylene, which will help the industry understand the place of this bio-based plastic and increase the offering of more sustainable products. • This study reports environmental impacts related to sugarcane-based polyethylene. • Land-use change highly influences the global warming potential of bio-polyethylene. • Bio-polyethylene can help fight climate change if no deforestation occurs. • Policies protecting forests are required to ensure benefits of bio-polyethylene. [ABSTRACT FROM AUTHOR]

Abstract: We estimated financial returns and wood production costs in 2008 for the primary timber plantation species. Excluding land costs, returns for exotic plantations in almost all of South America – Brazil, Argentina, Uruguay, Chile, Colombia, Venezuela, and Paraguay – were substantial. Eucalyptus species returns were generally greater than those for Pinus species in each country, with most having Internal Rates of Return (IRRs) of 20% per year or more, as did teak. Pinus species in South America were generally closer to 15%, except in Argentina, where they were 20%. IRRs were less, but still attractive for plantations of coniferous or deciduous species in China, South Africa, New Zealand, Indonesia, and the United States, ranging from 7% to 12%. Costs of wood production at the cost of capital of 8% per year were generally cheapest for countries with high rates of return and for pulpwood fiber production, which would favor vertically integrated firms in Latin America. But wood costs at stumpage market prices were much greater, making net wood costs for open market wood more similar among countries. In the Americas, Chile and Brazil had the most regulatory components of sustainable forest management, followed by Misiones, Argentina and Oregon in the U.S. New Zealand, the United States, and Chile had the best rankings regarding risk from political, commercial, war, or government actions and for the ease of doing business. Conversely, Venezuela, Indonesia, Colombia, and Argentina had high risk ratings, and Brazil, Indonesia, and Venezuela were ranked as more difficult countries for ease of business. [Copyright &y& Elsevier]

• MNFC increased the tensile index of tissue paper but decreased water absorbency and softness. • MNFCs from NBSK and SBHK yielded comparable trade-offs in tissue properties. • MNFC from BEK showed the lowest improvement in tensile index and degree of fibrillation. • MNFC from DIP had a performance comparable to MNFCs from virgin fibers and the lowest manufacturing cost. • MNFCs having similar degrees of fibrillation could be used interchangeably for enhancing strength. This study aims to understand the effect of micro- and nanofibrillated cellulose (MNFC) on the tensile index, softness, and water absorbency of tissue paper. MNFC was produced from four different fiber sources. The results show that MNFC acts as an effective strength enhancer at the expense of a reduced water absorbency and softness. The impact of the fiber source on MNFC manufacturing cost and the trade-off with performance was also investigated. MNFCs produced from southern bleached hardwood kraft, northern bleached softwood kraft, and deinked pulp exhibited similar performance trends with the MNFC from the deinked pulp having a significantly lower cost. This suggests that MNFCs with similar degrees of fibrillation may be used interchangeably regardless of the fiber source, revealing the possibility to minimize MNFC manufacturing costs based on fiber selection. MNFC produced from bleached Eucalyptus kraft showed the lowest degree of fibrillation and the lowest strength improvements among the MNFCs evaluated. [ABSTRACT FROM AUTHOR]