Efforts to improve the quality of life in rural areas rely upon the provision of electrical energy services. Globally, the focus is on identifying and maintaining sustainable and environmentally ...friendly energy resources, by means of the clean development mechanism (CDM). Supplying electricity by extending the grid to rural domains is, in most cases, economically unproductive, taking into account other related factors that pertain, especially in developing countries. Furthermore, an unfolding energy crisis in the sub-Saharan Africa (SSA) region intensifies the need for decentralized bioenergy applications using modern conversion techniques. Biomass energy produced in rural areas provides a sustainable alternative to grid electricity. This paper presents an overview of the potential of agricultural biomass-based resources for decentralized energy in rural areas of Ghana. It emphasizes the strategic importance of biomass energy, especially in areas where it is economically attractive because of the ready availability of resources. Assimilation of past and current research reported in the literature on biomass resources and bioenergy technologies in the country underpins this study. A more detailed evaluation of agricultural biomass-based potential was carried out and 2010 was chosen as the base period for the assessment. The result suggests that Ghana has a suitable potential of bioenergy resources and this holds considerable promise for future energy delivery in the country. The paper concludes with discussion of various promising decentralized bioenergy technologies for the exploitation of resources in Ghana.
Aim: Climate change intensifies the hydrological cycle and consequently alters precipitation regimes. Accurately assessing future carbon (C) budgets depends on understanding the influence of altered ...precipitation on both aboveground C cycling and belowground processes. Our goal was to explore generalities and mechanisms of responses of soil microbial communities to altered precipitation and implications for C cycling in terrestrial ecosystems. Location: Global. Time period: 2001–2017. Major taxa studied: Soil microbes. Methods: We used the meta-analytical technique to synthesize data of 41 increased (IPPT) and 53 decreased precipitation (DPPT) studies from 65 publications worldwide. The data covered broad variations in climate, percentage of precipitation change, experimental duration and soil properties. Results: The fungi to bacteria ratio did not show a water-tolerant shift, but the community compositions within the bacteria did. Microbial biomass showed a higher response to moderate IPPT than moderate DPPT, whereas it was more sensitive to extreme DPPT than extreme IPPT, suggesting that the responses of microbial biomass to altered precipitation are double asymmetric. However, such asymmetric responses of microbial biomass varied with climate humidity and soil texture: microbial biomass was more sensitive to IPPT at xeric sites than at mesic sites, whereas it was more responsive to DPPT in humid areas; microbial biomass in coarse-textured soils was more sensitive to altered precipitation than that in fine-textured soils. In addition, microbial response was positively correlated with the responses of aboveground/belowground plant biomass, soil respiration and organic C content. Main conclusions: Our meta-analysis provides the first evidence that the asymmetric response of microbial biomass to altered precipitation varies with climate humidity and soil texture. Given the coordinated responses in the plant–soil–microorganism C continuum, our synthesis extends the double asymmetric model and provides a framework for understanding and modelling responses of ecosystem C cycling to global precipitation change.
The idea of using less productive or “marginal land” for energy crops is promoted as a way to overcome the previous land use controversies faced by biofuels. It is argued that marginal land use would ...not compete with food production, is widely available and would incur fewer environmental impacts. This term is notoriously vague however, as are the details of how marginal land use for energy crops would work in practice.
This paper explores definitions of the term “marginal land” in academic, consultancy, NGO, government and industry documents in the UK. It identifies three separate definitions of the term: land unsuitable for food production; ambiguous lower quality land; and economically marginal land. It probes these definitions further by exploring the technical, normative and political assumptions embedded within them. It finds that the first two definitions are normatively motivated: this land should be used to overcome controversies and the latter definition is predictive: this land is likely to be used. It is important that the different advantages, disadvantages and implications of the definitions are spelled out so definitions are not conflated to create unrealistic expectations about the role of marginal land in overcoming biofuels land use controversies.
•Qualitative methods were used to explore definitions of the term “marginal land”.•Three definitions were identified.•Two definitions focus on overcoming biomass land use controversies.•One definition predicts what land will be used for growing biomass.•Definitions contain problematic assumptions.
Biodiesel, as one of the best alternative fuels, has a number of advantages over petro diesel, such as originating from a renewable and domestic feedstock which reduces the net production cost of ...biodiesel. In the recent years, biodiesel has received increasing interest due to energy crisis worldwide along with exhausting reserves and the shortage of oil supplies. The major problem behind the use of vegetable oil for biodiesel production is sustainability because it directly competes with human food. To combat this problem, the other renewable sources have been developed as microbial oils have similarity to vegetable oils and extensively used for biodiesel production. Oleaginous yeasts have recently been suggested as microscopic biofactories and alternative lipid producer to vegetable oil for a more sustainable biodiesel industry. It is a potential novel technology where non-edible lignocellulosic biomasses are exploited as raw materials for biodiesel production from oleaginous yeasts which drop net greenhouse gas emissions by substituting the practice of fossil fuels and would convey benefits to rural economies and national energy security. The usage of oleaginous yeasts have many advantages over other renewable sources like faster growth rate, shorter life cycle, easier scale-up, with no effects from the season and climate variation, and can serve as the excellent oil accumulating renewable feedstocks which are non-competitive to food resources and do not require arable land. Non-edible lignocellulosic biomass, consists of three different types of natural polymers, namely cellulose, hemicellulose, and lignin, is the most abundant renewable bioresource in the biosphere. The production of fermentable sugars from hydrolysates of various non-edible lignocellulosic biomass, either by physical, chemical or enzymatic hydrolysis has been utilized as feedstock in bioethanol or biodiesel production, extensively. During hydrolysis generation of non-carbohydrate compounds, such as 5- hydroxymethylfurfural (HMF), furfural acetic acid and phenolic compounds have various effects on the growth of microorganisms, their metabolism, as well as on final products, presenting a key challenge in the biological conversion of biomasses.
Lignin-derived carbon nanodots (LCNs) are nanometer-scale carbon spheres fabricated from naturally abundant lignin. Owing to rich and highly heritable graphene like π–π conjugated structure of ...lignin, to fabricate LCNs from it not only endows LCNs with on-demand tunable size and optical features, but also further broadens the green and chemical engineering of carbon nanodots. Recently, they have become increasingly popular in sensing, bioimaging, catalysis, anti-counterfeiting, energy storage/conversion, and others. Despite the enormous research efforts put into the ongoing development of lignin value-added utilization, few commercial LCNs are available. To have a deeper understanding of this issue, critical impacts on the preparation, properties, and applications of state-of-the-art LCNs are carefully reviewed and discussed. A concise analysis of their unique advantages, limitations for specific applications, and current challenges and outlook is conducted. We hope that this review will stimulate further advances in the functional material-oriented production of lignin.
Exploring new biomass sources for nanocellulose (NC) extraction is crucial in elevating the economic value of readily available renewable resources. This study compares NC extracted from acai ...(Euterpe oleracea) bagasse using different methods: mixed acid hydrolysis, 2,2,6,6-tetramethylpiperidinyl-1-oxy (TEMPO) mediation, and ammonium persulfate (APS) oxidations. A comprehensive analysis investigates the impact of each treatment on the physical-chemical properties of the nanoparticles, including chemical structure, crystallinity, morphology, and thermal and suspension stability. NCs obtained through mixed acid hydrolysis exhibit the highest crystallinity (62 %) and low sulfate groups on their surfaces. Consequently, they demonstrate excellent thermal stability but poor colloidal stability in water. Oxidized NCs undergo chemical modification, converting alcoholic groups into carboxyl, resulting in NCs with zeta potentials ranging between −25.30 ± 0.81 and − 27.49 ± 1.07 mV. APS oxidation produces nanoparticles with superior thermal stability compared to TEMPO oxidation. Atomic Force Microscopy (AFM) images reveal that all nanocelluloses share characteristics of nanofibers (CNFs). This comprehensive characterization highlights the potential of acai bagasse for yielding high-added-value bioproducts suitable for versatile applications.
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•Nanocellulose from acai bagasse was extracted by hydrolysis and oxidative methods.•APS and TEMPO oxidations produced distinct types of ionic charged nanocelluloses.•Mixed acid hydrolysis produced nanocellulose with better thermal stability.•All nanocelluloses from acai bagasse had nanofiber's characteristics.
The paper presents the possibility of managing forest and agricultural biomass for energy purposes in the aspect of environmental protection and sustainable development. The results of experimental ...studies of physicochemical properties of four types of plant biomass, i.e., a wheat straw, oat grains, larch needles and rapeseed pods are shown. The study consisted of determining the energy parameters in the form of gross and net calorific values of the test material. In addition, the ash and moisture content of the material was tested. Moreover, an elementary analysis for the tested materials by determining the content of carbon, hydrogen and nitrogen was performed. The studies have shown energy potential for the examined materials, in particular oat grains, where the gross calorific value amounted to 17.16 MJ·kg−1, net calorific value to 15.37 MJ·kg−1 and ash content to 2.71%. Larch needles are characterised by the highest carbon content of 45.73%, oat grains by hydrogen at 6.53%, 1.53% nitrogen and sulphur 0.11%. Determined emission rates indicate a reduction of 31–41% CO, 30–39% CO2, 22–55% NOx, 95–97% SO2, 47–97% dust depending on the type of used biomass in relation to hard coal.
Developing low‐cost single‐atom catalysts (SACs) with high‐density active sites for oxygen reduction/evolution reactions (ORR/OER) are desirable to promote the performance and application of ...metal–air batteries. Herein, the Fe nanoparticles are precisely regulated to Fe single atoms supported on the waste biomass corn silk (CS) based porous carbon for ORR and OER. The distinct hierarchical porous structure and hollow tube morphology are critical for boosting ORR/OER performance through exposing more accessible active sites, providing facile electron conductivity, and facilitating the mass transfer of reactant. Moreover, the enhanced intrinsic activity is mainly ascribed to the high Fe single‐atom (4.3 wt.%) loading content in the as‐synthesized catalyst.Moreover, the ultra‐high N doping (10 wt.%) can compensate the insufficient OER performance of conventional FeNC catalysts. When as‐prepared catalysts are assembled as air‐electrodes in flexible Zn–air batteries, they perform a high peak power density of 101 mW cm−2, a stable discharge–charge voltage gap of 0.73 V for >44 h, which shows a great potential for Zinc–air battery. This work provides an avenue to transform the renewable low‐cost biomass materials into bifunctional electrocatalysts with high‐density single‐atom active sites and hierarchical porous structure.
As‐prepared catalysts possess high‐loading single Fe atoms (4.3 wt.%) and ultrahigh nitrogen doping content (10 wt.%). Moreover, its tubular structure can expose more accessible active sites, provide facile electron conductivity, and facilitate the mass transport of reactants. As assembled to flexible Zn–air battery, it demonstrates a high open‐circuit potential (1.447 V) and outstanding power density (101 mW cm−2).
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•Floc deagglomeration happens significantly at 3.5 kJ/kg TS of ultrasonic energy.•Biomass lysis efficiency of 33.2% was achieved in phase separated disintegration.•Phase separation ...shows better amenability towards anaerobic biodegradation.•Net profit of about 2.67 USD/Ton was achieved in phase separated disintegration.
In this study, microwave irradiation has been employed to disintegrate the sludge biomass profitably by deagglomerating the sludge using a mechanical device, ultrasonicator. The outcomes of the study revealed that a specific energy input of 3.5 kJ/kg TS was found to be optimum for deagglomeration with limited cell lysis. A higher suspended solids (SS) reduction and biomass lysis efficiency of about 22.5% and 33.2% was achieved through ultrasonic assisted microwave disintegration (UMWD) when compared to microwave disintegration – MWD (15% and 20.9%). The results of biochemical methane potential (BMP) test were used to estimate biodegradability of samples. Among the samples subjected to BMP, UMWD showed better amenability towards anaerobic digestion with higher methane production potential of 0.3 L/g COD representing enhanced liquefaction potential of disaggregated sludge biomass. Economic analysis of the proposed method of sludge biomass pretreatment showed a net profit of 2.67 USD/Ton respectively.
•A case study representative of the energy production from eucalyptus residual biomass in the Portuguese pulp and paper industry.•Mass, energy and exergy flows highlighted through Sankey and ...Grassmann diagrams.•Energy and exergy efficiencies based on the useful produced superheated steam, and not on the energy and exergy losses.•Major improvements obtained decreasing the residual biomass moisture content.
This work deals with the mass, energy and exergy analyses of the energy conversion process in a 50 MWth thermal power plant, using residual forest biomass as fuel and integrating bubbling fluidized bed combustion technology. This is a representative case study of the energy production from eucalyptus residual biomass in the Portuguese pulp and paper industry. Analyses are made of the mass, energy and exergy flows, and how they change in the main components of the system, namely the combustion chamber, boiler, drum, superheater, economizer, and combustion air pre-heaters. Sankey and Grassmann diagrams highlight the mass, energy and exergy flows. Special emphasis is given to the energy and exergy efficiencies, which must be based on the useful produced superheated steam to include the influence of the biomass moisture content. The main goal is to find where and what potential exists for energy efficiency improvements. Results show that the main exergy destruction occurs in the combustion process, and that energy and exergy losses are minimal due to the system’s good thermal insulation. Results also show that the main potential for improvement is on the decrease of the residual biomass moisture content.
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