Cost Of Biomass Research Articles

Study on the carbon source stability of constructed wetland prepared from modified aged straw.

The low cost of biomass has made it an important option for providing carbon sources in the treatment of low carbon to nitrogen ratio (C/N) wastewater constructed wetland (CW). However, the unstable release of biomass carbon source reduces utilization and operation efficiency of CW. In this study, aged corn straw was used as raw material, and modification treatments with acid, alkali and oxidant were to optimize the conditions for stable carbon source release. The results showed that the modified straw exhibited three trends (stable release, continuous release, and short-term release) under water immersion conditions. The electrical conductivity (EC) of straw modified by HCl, H2SO4 and low-concentration KMnO4 (0.01molL-1) was low, so the supply of carbon sources in CW was obviously insufficient. The straw modified by HNO3 (1.5 or 2.5molL-1), KMnO4 (0.05molL-1), KMnO4 (0.05molL-1)+HCl (0.004molL-1) was continuously released chemical oxygen demand during the experiment, the increase in EC was significant, which could be used as an additional carbon source for CW. The research results will promote the improvement of biomass carbon source utilization in CW and improve the utilization value of straw.

Evaluation of the effects of immobilization on Spirulina platensis cultures

Different studies are carried out to reduce the production costs of Spirulina platensis biomass, which is produced in liquid cultures and has a high commercial value. These studies are in the direction of determining the optimum production method by changing the nutrient medium content and culture conditions. Immobilization is a method that changes the culture conditions. In our study, Luffa cylindrica (luffa), a natural fiber, was used for the immobilization of S. platensis cells, and the growth parameters and pigment production of the cultures were investigated. In two-factor experiments, week (first and second weeks) and culture type (free and immobilized cultures), statistically significant week*culture type interactions were found in optical density, dry weight, pH, and chlorophyll-a content. Immobilization did not increase the optical density and biomass production of the cultures. The highest optical densities and biomass productions were obtained in two-week-old free cultures, where the pH value was also found to be the highest. The highest values of chlorophyll-a and total carotene content were obtained from one-week immobilized cultures (30.06 µg/ml and 48.35 µg/ml, respectively). The fact that immobilization increased pigment production in one-week-old cultures indicates that when pigment production is targeted in S. platensis cultures, two-stage cultures that increase pigment yield via one-week immobilization after biomass production is completed can be used.

Design of a hybrid solar and biomass-based energy system integrated with near-zero energy building: Techno-environment investigation and multicriteria optimization

The current research aims to meet the energy needs of a group of residential buildings in Norway with the least amount of carbon dioxide emission and the greatest amount of renewable energy. The supply side based on the renewable renewable-based energy system is planned and scaled using the real-time data use of domestic hot water (DHW), heating and electricity necessary for the buildings. PVT panels are used in the hybrid solar and biomass-based energy systems to produce both the DHW requirements and the electricity production. The digester is used with the heat pump, which generates heat. A double-effect absorption refrigeration system is also utilized to provide the necessary cooling requirements. On the supply side, the management of the heat streams and the redirection of flows are done using a rule-based regulating system. The whole plant's size is supplied, and the dynamic energy simulation is run. The primary deciding criteria for heating the buildings are the costs of electricity and biomass. The whole system is then optimized depending on operating circumstances, and the outcomes are compared to the design point. PVT may be used to create more than 80 % of the yearly DHW. Furthermore, summertime radiation accounts for 64.8 % of cooling output since it is more intense and may be converted into cooling energy. Digester/CC also contributes 66.55 % of the building's heating, showing that the designers should rely on biomass as wintertime energy costs are higher. The parametric study demonstrates that increasing PVT time and tank capacity has varied effects on efficiency and emissions. Also, On winter days, there was a significant drop in renewable energy generation from summer to autumn, from 82.7 MWh to 28.52 MWh. The optimization results show that at the TOPSIS point, the total cost, efficiency, and emission index are 9.73 $/hr, 36.8 %, and 7.75 kg/MWh, respectively.

Thermodynamic and exergo-economic evaluation of biomass-to-X system combined the chemical looping gasification and proton exchange membrane fuel cell

The resource utilization of biomass is of great significance to the adjustment of energy structure. The syngas produced by biomass gasification can be used for power generation and production of green chemical raw materials. In this paper, a biomass-to-X (BtX) system based on the chemical looping gasification and high temperature proton exchange membrane fuel cell (PEMFC) is proposed to produce methanol, electricity, heating and cooling. The heat produced by the BtX system is harnessed for the regeneration of the carbon capture solution, as well as to drive both the organic Rankine cycle and the double-effect absorption chiller, enabling cascade utilization of the energy. The thermodynamic and exergo-economic models are carried out to evaluate system performance. The relationship between the material, energy and cost flow from biomass to products is analyzed. Finally, the influence of key parameters on system performance is studied. The results show that the energy efficiency of the BtX system is 54.0 % and the exergy efficiency is 35.4 %. The yield rate of methanol with 99.2 wt% purity is 6.48 tons/h. The cost of equipment, propanol and biomass accounts for 34.9 %, 28.9 % and 28.1 % of the total investment cost, respectively, while the cost of the PEMFC stack represents 50.4 % of the equipment costs. The unit exergy cost of the electricity and methanol are 0.068 $/kWh and 0.049 $/kWh, respectively. The methanol, carbon capture and cooling costs are most sensitive to the change in the propanol cost, followed by the biomass cost. For every 0.05 increase in the hydrogen fraction to methanol production, the electricity decreases by 3.1 MW and the methanol yield increases by 0.23 kg/s.

Green pathways for biomass transformation: A holistic evaluation of deep eutectic solvents (DESs) through life cycle and techno-economic assessment

The utilization of renewable biomass resources to manufacture biofuels, chemicals, and materials has garnered considerable attention. Deep eutectic solvents (DESs) have surfaced as a promising instrument within the realm of biomass conversion, owing to their distinctive attributes such as biodegradability, negligible toxicity, easier fabrication, liquid-phase stability and renewability as opposed to ionic liquids (ILs). Research into DESs, particularly those derived from natural sources, is expanding to advance affordable and sustainable biomass conversion. However, the bottlenecks of DES are its limited solubility for certain biomass constituents, cost and availability. To overcome these hurdles, ongoing research and technological innovations strive to tap into the complete potential of DESs in biomass conversion. This review underscores the importance of evaluating DESs' eco-friendly potential comprehensively, encompassing ecological, financial, and technological standpoints which aims to illuminate how DESs can effectively contribute to sustainable biomass utilization, fostering an environmentally conscious circular bio-based economy.

Data-driven based financial analysis of concentrated solar power integrating biomass and thermal energy storage: A profitability perspective

This study utilizes decision tree algorithms to estimate the financial feasibility of concentrated solar power (CSP). The main focus of CSP is on solar tower (ST) technology combined with two backup systems, such as biomass boilers and thermal energy storage (TES). The main goal is to develop three decision tree algorithms to predict the power plant's profitability factor (PF) for each of the following three operational scenarios: solar tower-base case-no biomass (ST-BC-NB), solar tower-operation strategy 1-medium biomass (ST-OS1-MB), and solar tower-operation strategy 2-full biomass (ST-OS2-FB). PF was predicted according to main input parameters, including direct capital costs, biomass cost, annual escalation rate, hourly electricity price, annual escalation rate, and peaks and troughs for daily electricity prices. Thermal energy storage was in five different capacities: no-thermal energy storage (No-TES), 5 h, 10 h, 15 h, and 20 h. The decision tree models demonstrated accurate predictions with low errors, high confidence levels, and most data falling within the 95% confidence interval for the "No-TES" case. Solar power plants with biomass backup had a 30% reduction in generation costs compared to conventional plants. The configurations without thermal energy storage had the highest profitability, with a maximum PF of −0.014 USD/kWh and a 25% chance of achieving profitability.

Optimizing Biomass Supply Chains to Power Plants under Ecological and Social Restrictions: Case Study from Poland

The growing demand for social and regulatory forest ecosystem services can significantly modify the availability and cost of biomass for energy purposes. This article presents a model for optimizing biomass supply chains using a linear programming framework integrated with a geographic information system (GIS). Based on a given type of biomass resource, its calorific value, price, distance from the power plant, and transportation costs, the model identifies the optimal source of biomass, allowing it to cover the demand for the required total energy value with the lowest possible costs. The case study includes the Połaniec power plant in southeastern Poland and potential sources of forest biomass and agricultural straw within 100 km of the plant. The impact of constraints on the availability and cost of biomass was analyzed in the following scenarios: (1) all forest and agriculture biomass is available, (2) forest area in Natura 2000 network is excluded, and (3) firewood and forests with dominated ecological and social function are excluded. Unit costs of biomass varied depending on biomass availability and energy demands. The lowest unit costs of biomass (3.19 EUR/MJ) were for energy demand at the level of 1 TJ yearly for all kinds of biomass and the highest (4.91 EUR/MJ) for ecological and social constraints and energy demand 4 TJ. As energy demand increased, unit costs increased, and the ability to meet this demand with just one type of biomass decreased. The energy biomass sector can utilize the model to benefit both biomass producers and their final buyers.

Forest resource distribution and transport cost optimization-based economic evaluation of gasification and steam-turbine biomass power generation systems

The economics of decentralized gasification and centralized steam turbine systems with optimized harvesting, chipping, and transportation costs of unutilized forest biomass were analyzed within the context of the spatial distribution of forest biomass resources using a geographic information system in the Fuji area of Shizuoka Prefecture, Japan. The optimized harvesting, chipping, and transportation costs were 62.50 USD/dry-t for the decentralized system and 65.86 USD/dry-t for the centralized system, confirming that the decentralized system was less expensive than the centralized system. However, electricity production costs for centralized systems, ranging from 0.137 USD/kWh (capacity: 5,000 kW), were found to be more economical than that for decentralized systems, at 0.151–0.165 USD/kWh (capacity: 482 kW), resulting in the higher costs of decentralized systems because of expensive initial investment than that of the centralized system. The rate of heat sold, which lowers the electricity production costs of gasification below those of centralized systems, was 20–40 % for all such plants. To lower the electricity production cost of gasification plants below that of steam-turbine systems, a heat sales rate of approximately 10% and a minimum staff of 0.2 persons for remote operation of the gasification system. Higher heat sales rates further decrease the cost of gasification, making it cheaper than steam-turbine systems even at lower operating rates. To achieve this cost advantage at current low utilization rates, a heat sales rate of 50% and a utilization rate of 90%, based on a unit price of 0.05 USD/kWh, are required.

A Multi-Tissue Genome-Scale Model of Populus trichocarpa Elucidates Overexpression Targets for Improving Drought Tolerance

Abstract Populus trichocarpa (poplar) is a fast-growing model tree whose lignocellulosic biomass is a promising biofuel feedstock. Enhancing its viability and yield in non-arable drought-prone lands can reduce biomass cost and accelerate adoption as a biofuel crop. Data from extensive -omics and phenotypic studies were leveraged herein to reconstruct a multi-tissue (root, stem, and leaf) genome-scale model (GSM) of poplar, iPotri3463, encompassing 14,360 reactions, 12,402 metabolites, and 3,463 genes. Two condition-specific GSMs were extracted from iPotri3463: iPotri3016C (control) and iPotri2999D (drought), supported by condition-specific transcript levels and reaction essentiality for growth. Physiological constraints consistent with experimental measurements of drought-stressed plants were imposed to growth, photorespiration, and carbon assimilation rates. Calculated increased flux capacity through the violaxanthin cycle and GABA biosynthetic pathways agree with established key strategies for improving drought tolerance. Differential gene expression analysis was performed on existing transcriptomes of poplar under different watering regimes. Computational flux knockdown was applied to reactions with increased flux capacity under drought which were associated with at least one downregulated gene. Several such reactions were essential for maintaining observed biomass yield and their associated genes are candidates for overexpression to improve drought tolerance. Glutamine synthetase is one whose overexpression in poplar confirms in silico predictions. However, the two most promising candidates are genes encoding ferulate-5-hydroxylase, Potri.007G016400 and Potri.005G117500, as their overexpression in other plant species led to demonstrably improved drought tolerance while previous overexpression in poplar reduced biomass recalcitrance. iPotri3463 is the first poplar-specific whole-plant GSM and the second one available for a woody plant.

Life cycle emissions and unit production cost of sustainable aviation fuel from logging residues in Georgia, United States

Production of Sustainable Aviation Fuel (SAF) has gained popularity for reducing carbon emissions from the aviation sector. To evaluate the environmental and economic tradeoffs related to SAF production and its potential use, this study estimates the life cycle carbon emissions and unit production cost of SAF produced from logging residues generated during harvest and thinning operations in Georgia, a major roundwood producing state in the Southern United States. We considered two production pathways, i.e., Ethanol-to-Jet (ETJ) and Iso-Butanol-to-Jet (Iso-BTJ), to compute the carbon savings and unit production costs. A sensitivity analysis was performed to identify significant factors contributing to the overall carbon savings and unit production costs for the selected pathways. After considering revenues generated from co-products, the minimum aviation fuel selling price (MASP) was $2.71 L-1 and $2.44 L-1 for ETJ and Iso-BTJ pathways, respectively. Capital investment cost at biorefinery accounted for most of the MASP, followed by the minimum haul rate for transporting biomass and variable cost for alcohol intermediate production. Finally, after considering tax credit from the Inflation Reduction Act of 2022 and RIN (Renewable Identification Number) credit along with co-product revenue, the MASP ranged between $2.29 L-1 and 0.83 L-1 for the ETJ pathway and between $2.04 L-1 and $0.59 L-1 for the Iso-BTJ pathway. In addition, the carbon intensity of both the ETJ and Iso-BTJ pathways were 758 g CO2e L−1 and 976 g CO2e L−1, with relative carbon savings of 70.6 % and 62.1 % compared to conventional aviation fuel. The production cost suggests a minimum abatement cost of $59 t CO2e−1 for the ETJ and -$59.3 t CO2e−1 for the Iso-BTJ pathways in the presence of federal incentives. Our study shows that logging residues-based SAF could reduce the overall carbon footprint of the aviation sector; however, policy support is needed to support its production in light of higher production costs.

Optimal sizing of hybrid PV–diesel–biomass gasification plants for electrification of off-grid communities: An efficient approach based on Benders’ decomposition

Nowadays, millions of people in remote areas do not enjoy an uninterrupted power supply due to the lack of connectivity to the main power grid. Under such circumstances, the only feasible way to access electricity is typically local power generation, often relying on diesel engine–generator sets or photovoltaic arrays. However, on many occasions, this configuration does not fully exploit all available local resources, including biomass. Indeed, most isolated areas have access to local biomass production from agricultural activities, which can be used for local electricity generation through gasification. This paper addresses this challenge by developing an innovative optimal sizing tool for hybrid power plants integrating biomass gasifiers, specifically designed for isolated areas with access to local biomass production. The novel approach models the particular features of biomass gasification technologies, including long on/off times or restrictive ramping limits. To this end, an efficient methodology based on representative weeks is proposed, which is combined with a solution strategy based on the multi-cut Benders’ decomposition, thus resulting in a tractable framework that can deal with a huge amount of data efficiently. One of the most salient features of the new proposal is the consideration of local biomass production, which is included in the methodology through an original algorithm. Accordingly, a certain amount of biomass is sourced locally, leading to more accurate and reliable results. The new methodology is applied to a benchmark off-grid community in Ghana. The results demonstrate that the use of gasifiers reduces the project cost notably (by 90%) driven by the reduced biomass cost, which can be supplemented by locally generated biomass from agricultural activities. In addition, this technology constitutes a clean source of energy, reducing the total CO2 emissions by 83% compared to a baseline case in which only diesel generators are used. Moreover, it is demonstrated that biomass gasification can effectively act as base load power generation technology to reliably cover most of the local demand, thereby enabling a clean and inexpensive dispatchable local power generation. Finally, a sensitivity analysis reveals that the economic feasibility of the plant is more sensitive to the biomass cost than the selling price of biochar, resulting in a 33% increment in the total project cost when the price of biomass increases from 0 to 0.4 $/kg. Nevertheless, gasification remains as the predominant power generation technology even under unfavorable prices.

Indole-3-Acetic Acid Action in Outdoor and Indoor Cultures of Spirulina in Open Raceway Reactors

A significant research gap exists in investigating large-scale microalgae cultures exposed to outdoor conditions, with the addition of phytohormones using non-sterile growth media. Implementing these conditions is crucial for verifying the industrial viability of this strategy. This study aimed to evaluate the effect of indole-3-acetic acid (IAA) supplementation on Spirulina sp. LEB 18 cultures conducted indoors and outdoors in raceway bioreactors. The outdoor experiments were performed under uncontrolled environmental conditions. The indoor cultures were maintained within a thermostat-controlled chamber at a consistent temperature and lighting intensity. The outdoor experiments supplemented with IAA achieved a biomass concentration of 5.43 g L−1 and productivity of 173.9 mg L−1 d−1. These values increased 122.5% and 130.9% in biomass concentration and productivity, respectively, compared to the indoor experiments with the same supplementation. Moreover, roughly half of the biomass generated from outdoor cultivation with IAA consisted of carbohydrates (45%). Compared to indoor cultivation, this approach reduced production costs for biomass (55%) and lowered production costs for carbohydrates, proteins, and lipids by 86%, 44%, and 50%, respectively. The successful application of phytohormones in microalgae cultures, particularly under larger scale, nonsterile, and outdoor conditions, represents a significant advancement toward industrial implementation.

Dynamic marine spatial planning for conservation and fisheries benefits

AbstractThe increasing global demand for marine resources raises concerns about sustainable resource management and biodiversity conservation. Spatial closures, such as marine protected areas, can be valuable tools for maintaining and restoring exploited populations. When these spatial closures adopt a dynamic nature being adapted to the changing environment, they can effectively account for factors such as shifting species distributions, which enhances their potential to achieve ecological and socio‐economic objectives. Here, we adapted a decision‐support tool (the software Marxan), typically used for selecting static and permanent areas, to produce management recommendations that integrate permanent and temporal closures to fisheries. Our aim was to compare the outputs of a static network of permanent no‐take reserves with four other dynamic scenarios, including permanent and temporal closures that account for seasonal variations in the populations of species. All scenarios prioritized sites for the conservation of one of the most valuable European fishing stocks, the Norway lobster (Nephrops norvegicus). Additionally, we considered 12 other commercially exploited species captured by the Norway lobster fishery. The assessed outputs included retained biomass, area extent, closure type (permanent and seasonal) and opportunity costs within each scenario. We observed that all dynamic scenarios required fewer management areas permanently closed than the static scenario. This resulted in a lower opportunity cost for fisheries but also a higher capacity for biodiversity conservation. Therefore, complementing permanent with temporal closures could enhance biodiversity conservation and fisheries management. The novel dynamic planning method presented here could be applicable to other species, ecosystems and socio‐economic contexts.

A review of technoeconomic benefits of torrefaction pretreatment technology and application in torrefying sawdust

Economic analysis of torrefaction process centers on assessment of the economic feasibility of the production and utilization of torrefied biomass using developed models such as costs of biomass, electricity, labour, investment, transportation etc. to evaluate the cost of biomass torrefaction. The increase in energy usage over the past century has raised concern over the energy insecurity and environmental unsustainability of current fossil fuel utilization; therefore, there is need for energy diversification. An attractive alternative is the biomass. However, the poor performance of raw biomass in energy generation further necessitate development of refined technologies to enhance its performance, particularly at low temperatures between 200–300 ℃. This study therefore reviews the technoeconomic benefits of torrefaction technology and reactors and its application in the pretreatment of sawdust. An overview of torrefaction technology, torrefied product characteristics, and economic analysis of torrefier reactor and torrefaction cost/ton were reviewed. From the review, torrefaction significantly improved the physical, combustion and performance characteristics of torrefied products, with comparable durability and storability to raw biomass. Comparing with other thermal pretreatment methods, torrefaction is an economical way of improving biomass properties.

A technical-economic analysis of integrating vine prunings energy conversion systems for CHP production in local wineries

This study proposes the energy conversion of vine prunings to supply energy to local wineries, with a focus on the Riunite & CIV branch winery located in Carpi (Modena, Italy), exploring the possibility of generating both electricity and heat through biomass gasification. A Matlab-Simulink model is used to evaluate the energy savings that can be achieved when an energy storage system is coupled with the combined heat and power generation system. Within this context, the results showed that it is possible to save ≈\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\approx $$\\end{document}30% of the electricity and ≈\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\approx $$\\end{document}60% of the thermal energy demanded by the winery. However, the economic viability of the project is hindered by high investment and operation costs. DPB is strongly affected by the cost of biomass and the energy prices, resulting in a profitable investment for electricity prices higher than 0.30 ÷>\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\div>$$\\end{document}0.57 €/kWh according to the different scenarios investigated.

Market analysis of coupled biochar and carbon credit production from wildfire fuel reduction projects in the western USA

AbstractThe investment potential for biochar production from low‐value forest biomass in the western USA is over USD 20 billion at current carbon prices. This investment could generate approximately 70 million carbon credits annual – roughly the same number currently generated globally by all forestry and agricultural carbon projects. Biochar production that utilizes woody biomass specifically from wildfire fuel thinning projects as a feedstock can contribute financially to much‐needed fuel thinning projects. Each coupled biochar and carbon credit production system has positive returns in certain scenarios. Light upgrades to existing biopower facilities have the highest returns, with internal rates of return generally between 10–30%. Mobile biochar production often had the lowest returns. However, land managers can subsidize mobile biochar production up to USD 150–300 per tonne of biochar and still save money in comparison with pile‐burning low‐value biomass while also generating approximately one carbon credit for every two bone‐dry tonnes of low‐value biomass turned to biochar. The critical barrier to industry growth is the lack of transparent biomass supply chains that enable long‐term contracting for feedstock, production schedules, and investment. Moving forward, there are three potential pathways for the biochar industry to scale and utilize biomass from forest management and fuel thinning projects. Either (1) the carbon market will need to sustain high carbon prices, (2) a subsidy or other mechanism will need to decrease the cost of feedstock biomass, or (3) production will need to take advantage of economies of scale to bring down biochar prices while increasing production.

Economic potential of agricultural-riparian shrub willow: An evaluation of the biomass producing capabilities and costs of cultivating Salix viminalis downslope of potato cropping systems in PEI

Shrub willow (Salix spp.) is increasingly grown as a biomass crop and for a range of environmental applications. Merging the economic and environmental objectives of willow production may facilitate more widespread adoption by reducing production costs and justifying willow cultivation in traditional agricultural settings. Incorporating willow in agricultural-riparian transition areas, particularly in intensive or high-input agricultural systems, can enhance watercourse protection from diffuse pollutants, mitigate indirect agricultural N2O emissions, and sequester carbon. However, biomass accrual and economic feasibility needs quantification on localized scales.This study investigated the biomass accrual of 9 agricultural-riparian willow buffers in Prince Edward Island, Canada, receiving no direct fertilization. Carbon, nitrogen, and phosphorus assimilation was measured in stem and root biomass, limitations on growth assessed, and benefit-cost analysis was conducted to determine opportunities for bioenergy use and deployment. First rotation agricultural-riparian Salix viminalis displayed considerable site-to-site variation in biomass production, with water availability being the primary limiting factor on growth. Mean total plant biomass and annual yield ranged from 0.54 to 7.9 kg dry matter plant−1 and 0.25–16.59 Mg ha−1 yr−1 (mean 3.9), respectively. CO2 fixation was 0.67–46.64 Mg CO2 ha−1 yr−1, of which 0.23–15.7 Mg CO2 ha−1 yr−1 was root biomass, indicative of long-term sequestration. Nitrogen and phosphorus removal was 6.05–39.1 (mean 23.3) and 1.1–4.8 (mean 2.8) kg ha−1 yr−1. Benefit-cost analysis revealed that shrub willow production can be economically viable for on-farm heating when yields exceeding 5.6 Mg dry matter ha−1yr−1 are achieved, but off-farm sale is not currently economically justified.

Pollutant Gases to Algal Animal Feed: Impacts of Poultry House Exhaust Air on Amino Acid Profile of Algae.

Algae provide a rich source of proteins, lipids, vitamins, and minerals, making them valuable feed ingredients in animal nutrition. Beyond their nutritional benefits, algae have been recognized for their potential to mitigate the negative environmental impacts of poultry production. Poultry production is crucial for the global food supply but contributes to environmental concerns, particularly in terms of ammonia and carbon dioxide gas emissions. This study emphasizes the importance of reducing greenhouse gas and ammonia production in poultry operations by utilizing algae species suitable for animal consumption, highlighting the need for sustainable feed sources. This study investigated the effects of poultry exhaust air and culture conditions on the amino acid profiles of three microalgae species, namely, Scenedesmus sp. (AQUAMEB-60), Ankistrodesmus sp. (AQUAMEB-33), and Synechococcaceae (AQUAMEB 32). The experiments were conducted in a commercial broiler farm in Bursa, Turkey, focusing on reducing pollutant gas emissions and utilizing poultry exhaust air in algae cultivation. The highest protein content of 50.4% was observed in the biomass of Synechococcaceae with BBM and DI water. Scenedesmus sp. had the highest carbohydrate content of 33.4% cultivated with DI water. The algae biomass produced from Synechococcaceae growth with DI water was found to have the highest content of essential and nonessential amino acids, except for glutamic acid and glycine. The arsenic, cadmium, and mercury content showed variations within the following respective ranges: 1.076-3.500 mg/kg, 0.0127-0.1210 mg/kg, and 0.1330-0.0124 mg/kg. The overall operating costs for producing 1.0 g L-1 d-1 of dry algal biomass with the existing PBR system were $0.12-0.35 L-1 d-1, $0.10-0.26 L-1 d-1, and $0.11-0.24 L-1 d-1 for Scenedesmus sp., Ankistrodesmus sp., and Synechococcaceae, respectively. The operating cost of producing 1.0 g L-1 d-1 of protein was in the range of $0.25-0.88 L-1 d-1 for the three algae species. The results provide insights into the potential of algae as a sustainable feed ingredient in animal diets, emphasizing both environmental and economic considerations. The results demonstrated a considerable reduction in the production costs of dry biomass and protein when utilizing poultry house exhaust air, highlighting the economic viability and nutritional benefits of this cultivation method.

Coal Share Reduction Options for Power Generation during the Energy Transition: A Bulgarian Perspective

The sustainable energy transition to a low-carbon and climate-neutral economy by 2050 requires a consistent increase in the share of renewable energy sources (RESs) at the expense of the share of fossil fuels. The coal power plants in the Republic of Bulgaria have provided about one third of the annually produced electric power for decades, utilizing mainly locally available sources of lignite. The present work aimed to review the progress of the energy transition, its rejection and acceptance at the national and international scene alongside the available research for cleaner coal combustion in Bulgaria, as well as discuss a Bulgarian perspective for coal share reduction options for power generation during the energy transition. A comprehensive review was carried out, based on freely accessible data such as research and open media articles, officially published field reports, legislative and strategic acts as well as validated statistical data. Three groups of critical gaps (socioeconomic, sociotechnical and cultural and political) were indicated, claimed to be capable of guiding the just transition. Key factors influencing the process dynamics were identified and categorized in the context of the critical gaps. The peculiar policy criteria for the carbon-intensive regions are as follows: the dominant energy carriers, existing infrastructure, involved actors and choice of strategy. The observations allowed us to conclude that in addition to the efforts achieved and ambitious political will, the identification of reliable technological and socioeconomic measures is needed more than ever (accompanied by interdisciplinary research involving the technical, social and environmental and policy factors), while renewables still have long way to go towards complete substitution of the fossil fuels for power generation, transport, and manufacturing. Limited literature was found for reducing the share of coal from currently operating Bulgarian coal-fired power plants (CFPPs). Herein, short- and/or medium-term measures for carbon emission reduction were discussed, capable of promoting the limited operation of existing CFPPs, thus paving the road towards a sustainable, long-term transition. These measures concerned the typically used power units in the largest CFPPs located at the Maritsa Iztok Mining Complex (MIMC). Analyses of the biomass production, supply and cost for the same type of power units were proposed, considering the use of 100% biomass. Estimated costs, unit efficiencies and power generation were discussed along with the evaluations about the land use, ensuring a given annual productivity of wood chips from fast growing plants, e.g., Paulownia.

Linking root traits to phytoremediation in trees and shrubs: Implications of root economics spectrum

Abstract Phytoremediation is a promising technique for removing or stabilizing metal ions from metallic trace elements (MTEs) contaminated soils. Despite the significant role of roots in plant growth and survival, limited information is available on the functional covariation of root traits under MTE stress, and linkages between root resource‐use strategies and phytoremediation functioning. Sixteen root traits were measured across 11 trees and shrubs grown in Pb–Zn mine tailings in Southeastern China, to examine whether a hypothesized root economics spectrum (RES) exists under extremely high levels of multiple MTEs stress and evaluate the importance of root functional traits in explaining phytoremediation functioning. Our findings offer evidence supporting the widely accepted resource‐use strategy of acquisitive‐conservative. Furthermore, we have identified a distinct dimension of RES representing the trade‐off between root system size and root tissue density. This new dimension highlights the critical importance of root size, shape and proliferation strategy in the context of metal‐contaminated soil. Moreover, a trade‐off between root cadmium concentration and root dry matter content was observed, which implies the existence of a presumable biomass cost for MTEs accumulation. We identified specific key root traits and their contributions to MTE translocation and bioconcentration, and established linkages between root resource‐use strategy and phytoremediation: roots with more acquisitive traits promote MTE translocation, while conservative roots foster bioconcentration. In addition, acquisitive roots usually exhibit lower biomass costs for accumulating MTEs than do conservative roots. Synthesis and applications. Our results highlight the important role of root size‐related traits in the root economics spectrum (RES) framework in metal‐contaminated soil. Furthermore, we discovered that woody species exhibit different capacities for accumulating or translocating metallic trace elements (MTEs), depending on their root system shapes and their position on axis of RES. These findings provide valuable support for the accurate selection of suitable plant species for ecological restoration purposes. And they hold significant potential in guiding the development of efficient phytoremediation strategies specifically targeting sites contaminated with MTEs.