Nigerian Biomass for Bioenergy Applications:A Review on the Potential and Challenges

Nigeria,often referred to as“the giant of Africa,”boasts a sizable population,a thriving economy,and abundant energy resources.Nevertheless,Nigeria has yet to fully harness its renewable energy potential,despite its enormous capacity in this field.The goal of this review paper is to thoroughly examine the difficulties and untapped opportunities in utilizing biomass for bioenergy production in Nigeria.Notably,Nigeria generates substantial volumes of biomass annually,primarily in the form of agricultural waste,which is often either discarded or burned inefficiently,resulting in significant ecological and environmental damage.Therefore,an efficient approach to reducing pollution and transforming waste into wealth involves converting these biomass resources into energy.This work critically examines the status of biomass utilization for energy applications in Nigeria and highlights the bottlenecks that impede its widespread adoption.The review emphasizes the economic and ecological advantages of biomass utilization over traditional waste treatment methods.Additionally,it underscores the appeal of biomass as an industrial fuel source,particularly considering the current high cost of fossil fuels in contemporary Nigeria.Relevant literature on biomass,energy,agricultural waste,fossil fuel,and calorific value in the context of Nigeria was reviewed by utilizing a thorough search technique in key scientific databases.The analysis did not include any non-English publications.The findings of this research provide valuable insights into the challenges faced in maximizing Nigeria’s biomass potential and offer strategic recommendations to promote the use of biomass for bioenergy development.This review paper will assist a wide range of local and international readers,as well as industries interested in green and bioenergy,in making informed decisions regarding the most suitable types of biomass for biofuel production.

Bioenergy Perspectives in the EU Regions: Carbon Neutrality Pathway

Bioenergy plays an important role in the climate neutrality targets of the EU. However, the status of bioenergy implementation varies greatly across the EU. The aim of this paper is to assess the role of bioenergy in different EU countries using EU experts’ opinions of bioenergy implementation in their own country. The paper identifies leading and lagging countries in biomass development by focusing on the current share of bioenergy in the total energy supply. The study shows differences in bioenergy development between Southern and Western EU countries with Northern and Eastern EU countries. The anti-bioenergy movement and continuing political support for the fossil fuel industry are important barriers inhibiting biomass development in many EU countries, especially in Southern Europe and Western Europe. Our analysis finds that the EU needs more factual bioenergy information and improved promotion of bioenergy throughout society, especially in southern and western parts of the EU. Bioenergy development in the EU can be looked at optimistically, especially in Northern and Eastern Europe. The experience of societal acceptance of bioenergy in countries such as Finland and Sweden is applicable to countries that have thus far seen less progress in bioenergy implementation such as Poland and the Netherlands.

A study on the bioenergy crop production function of land use in China

Based on the analysis of the bioenergy crop production function of land use,combined with the status quo of Chinese land use,the cultivation of energy plants and the bioenergy crop production function of land use had been analyzes and discusses in this paper.Results show that there were a lot of unused lands and marginal lands which can be planted bioenergy crops to perform the bioenergy crop production function of land use with great potentials;and currently there were no food production problems.Therefore,it was very important for China to emphasize bioenergy crops planting in order to fully use land resources in our country,moderate the energy crisis and increase peasants' income.

Switchgrass as a bioenergy crop in the Loess Plateau, China：Potential lignocellulosic feedstock production and environmental conservation

A large portion of the Loess Plateau of China is characterized as “marginal” with serious land degradation and desertification problems. Consequently, two policies, Grain for Green and Western Development Action were established by the Chinese government in response to the demand for ecological protection and economic development in the Loess Plateau. These policies are designed to increase forest cover, expand farmlands, and enhance soil and water conservation, while creating sustainable vegetation restoration. Perennial grasses have gained attention as bioenergy feedstocks due to their high biomass yields, low inputs, and greater ecosystem services compared to annual crops. Moreover, perennial grasses limit nutrient runoff and reduce greenhouse gas emissions and soil losses while sequestering carbon. Additionally, perennial grasses can generate economic returns for local farmers through producing bioenergy feedstock or forage on marginal lands. Here, we suggest a United States model energy crop, switchgrass（Panicum virgatum L.） as a model crop to minimize land degradation and desertification and to generate biomass for energy on the Loess Plateau.

Sweet sorghum and Miscanthus：Two potential dedicated bioenergy crops in China

Among the potential non-food energy crops,the sugar-rich C4 grass sweet sorghum and the biomass-rich Miscanthus are increasingly considered as two leading candidates.Here,we outline the biological traits of these energy crops for largescale production in China.We also review recent progress on understanding of plant cell wall composition and wall polymer features of both plant species from large populations that affect both biomass enzymatic digestibility and ethanol conversion rates under various pretreatment conditions.We finally propose genetic approaches to enhance biomass production,enzymatic digestibility and sugar-ethanol conversion efficiency of the energy crops.

A Hybrid Biofuel and Triboelectric Nanogenerator for Bioenergy Harvesting

Various types of energy exist everywhere around us,and these energies can be harvested from multiple sources to power micro-/nanoelectronic system and even personal electronic products.In this work,we proposed a hybrid energy-harvesting system(HEHS)for potential in vivo applications.The HEHS consisted of a triboelectric nanogenerator and a glucose fuel cell for simultaneously harvesting biomechanical energy and biochemical energy in simulated body fluid.These two energy-harvesting units can work individually as a single power source or work simultaneously as an integrated system.This design strengthened the flexibility of harvesting multiple energies and enhanced corresponding electric output.Compared with any individual device,the integrated HEHS outputs a superimposed current and has a faster charging rate.Using the harvested energy,HEHS can power a calculator or a green light-emitting diode pattern.Considering the widely existed biomechanical energy and glucose molecules in the body,the developed HEHS can be a promising candidate for building in vivo self-powered healthcare monitoring system.

A technical and socioeconomic approach to estimate forest residues as a feedstock for bioenergy in northern Mexico

Background: Forest residues can be a feasible alternative for converting energy into fuels, electricity, or heat.Compared to other second-generation bioenergy sources, they do not compete for food, are relatively cheap,abundant in forest-rich areas, and more importantly their energy balance is close to zero. Biomass estimations can help design energy strategies to reduce fossil fuels dependency. Because of the land property distribution in Mexico,biomass estimations should consider not only the physical availability, but also the willingness of landowners to extract such raw materials.Methods: This study presents a methodological approach for evaluating the potential use of forest residues as a feedstock to generate bioenergy in northern Mexico. Remote sensing and field forest inventory were used to estimate the quantity and distribution of forest residues. In addition, a discrete choice analysis evaluated landowners’ preferences towards bioenergy development, including the most important factors that influence their willingness to extract their products and the expected price.Results and conclusions: Considering both physical and socio-economic aspects, results showed that about59,000 metric tons per year could be available in the study area. The vast majority of landowners surveyed are willing to extract forest residues, as long as they are presented with extraction plans with the highest income. However, many showed concerns about the environmental impacts this activity can have on soils,plants, and fauna. These results can help evaluate the potential of these resources for bioenergy development.

Life cycle cost and economic assessment of biochar-based bioenergy production and biochar land application in Northwestern Ontario, Canada

Background： Replacement of fossil fuel based energy with biochar-based bioenergy production can help reduce greenhouse gas emissions while mitigating the adverse impacts of climate change and global warming. However, the production of biochar-based bioenergy depends on a sustainable supply of biomass. Although, Northwestern Ontario has a rich and sustainable supply of woody biomass, a comprehensive life cycle cost and economic assessment of biochar-based bioenergy production technology has not been done so far in the region. Methods： In this paper, we conducted a thorough life cycle cost assessment （LCCA） of biochar-based bioenergy production and its land application under four different scenarios： 1） biochar production with low feedstock availability; 2） biochar production with high feedstock availability; 3） biochar production with low feedstock availability and its land application; and 4） biochar production with high feedstock availability and its land applicationusing SimaPro, EIOLCA software and spreadsheet modeling. Based on the LCCA results, we further conducted an economic assessment for the break-even and viability of this technology over the project period. Results： It was found that the economic viability of biochar-based bioenergy production system within the life cycle analysis system boundary based on study assumptions is directly dependent on costs of pyrolysis, feedstock processing （drying, grinding and pelletization） and collection on site and the value of total carbon offset provided by the system. Sensitivity analysis of transportation distance and different values of C offset showed that the system is profitable in case of high biomass availability within 200 km and when the cost of carbon sequestration exceeds CAD S60 per tonne of equivalent carbon （CO2e）. Conclusions： Biochar-based bioenergy system is economically viable when life cycle costs and environmental assumptions are accounted for. This study provides a medium scale slow-pyrolysis plant scenario and we recommend similar experiments with large-scale plants in order to implement the technology at industrial scale.

China’s bioenergy industry development roadmap

Positive development of renewable energy, saving and substitution of fossil energy, promotion of the energy structure adjustment are the inevitable strategy choices of China’s sustainable development. This paper discussed the China’s bioenergy resources status, development targets and technology development roadmaps. China has 136.140 million hm2 of marginal land, which distribute mainly in western and northern regions. There are 1 billion t of crop residues and forestry waste annually, and 300 million t can be used to produce different kinds of bioenergies. And organic waste and manure can generate 50 billion m3 of biogas. The discussed development target indicated that it can construct a biomass oilfield with the capacity of 100 million t/year and reduce 200 million t of CO_2 emission by 2020. The bioenergy technology development roadmap indicated that the bioethanol mainly uses non grain starch and hemicellulose products as raw materials in the near-term (2006-2010). The biodiesel technology will focus on the advanced production technology, FT diesel, liquefaction of biomass and raw material production technology.

Utilization of Multi-Tasking Non-Edible Plants for Phytoremediation and Bioenergy Source-A Review

Heavy metal contamination of land and freshwater resources is a serious concern worldwide.It adversely affects the health of animals,plants and humans.Therefore,remediation of toxic heavy metals must be highly considered.Unlike other techniques,phytoremediation is a holistic technology and can be used in large scale for soil remediation as it is costless,novel,environmentally-safe and solar-driven technology.Utilization of non-edible plants in phytoremediation is an ingenious technique as they are used to generate new bioenergy resources along with the remediation of contaminated soils.Some nonfood bioenergy crops such as Salix species,Miscanthus species,Populus species,Eucalyptus species,and Ricinus communis exhibit high capability to accumulate various metals and to grow in contaminated lands.However,there are still sustainable challenges facing coupling phytoremediation with bioenergy production from polluted lands.Therefore,there has long been a need for developing different strategies to resolve such challenges.In this article review,we will discuss the phytoremediation mechanism,the technique of phytoremediation coupling with bioenergy production,sustainable problems facing linking phytoremediation with energy production as well as possible strategies to enhance the efficiency of bioenergy plants for soil decontamination by improving their characteristics such as metal uptake,transport,accumulation,and tolerance.

Row Spacing Affects Biomass Yield and Composition of Kenaf (<i>Hibiscus cannabinus</i>L.) as a Lignocellulosic Feedstock for Bioenergy

Kenaf (Hibiscus cannabinus L.) is a warm-season annual. Kenaf fibers are commonly used for paper pulp and cordage, but it is also a promising lignocellulosic feedstock for bioenergy production, although optimum plant density for biomass production has not been determined for the northern region of the USA. The objective of this study was to determine the best plant density and row spacing of kenaf to maximize biomass yield and chemical composition for biofuel conversion. The experiments were conducted at Fargo and Prosper, ND, in 2010 and 2011. The experiment was a randomized complete block design with a split-plot arrangement where the main plot was tworowspacings (30 and60 cm) and the sub-plot fourplant densities (32, 16, 8, and 4 plants·m-2). Row spacing had a significant effect on both biomass and biofuel yield. Narrower rows had higher biomass and biofuel yield. Maximum biomass and estimated biofuel yield was obtained with the two highest plant densities of 16 and 32 plants·m-2 and fluctuated between 9.45 and 10.22 Mg·ha-1 and 1354 and1464 L·ha-1, respectively. Stem diameter increased with a decrease in plant density. Chemical composition varied with plant density;glucan (27%) and xylan (9.8%) content were lower at the lowest plant density. Ash content was not different among plant densities but it is interesting to mention the very low ash content of kenaf (0.15%). According to the results of this study, it is recommended to plant kenaf at 30-cm rows with a plant density of 16 to 32 plants·m-2 to maximize biomass yield. Kenaf has a tremendous potential as a cellulosic feedstock for biofuel and green chemicals in the Northern Great Plains because of high biomass yield and low ash content.

An Investigation of the Carbon Neutrality of Wood Bioenergy

Wood biomass has been viewed as “carbon neutral”—its uses as energy have a zero carbon footprint. Some observers argue that the use of wood biofuels will result in a decrease of the forest stock and a net reduction of the carbon captured in the forest. Such assessments take a static, accounting view of forest systems and do not consider the effects of management in renewing the forest and increasing its extent or ability to sequester carbon. This paper addresses the carbon neutrality debate using a dynamic optimization forest management model to examine the effect on the existing and future forests of a changing demand for wood biomass. The results show that under market optimizing conditions, when future demand is anticipated to increase for significant periods, the response of managers will be to increase the intensity of forest production thereby offsetting much of the carbon released in bioenergy production.

Analysis on the Growth Rhythm and Cold Tolerance of Five-Year Old <i>Eucalyptus benthamii</i>Plantation for Bioenergy

A research plot of Eucalyptus benthamii was planted to evaluate this species’ ability to supply the emerging bioenergy markets that are developing in the southern U.S. The plot was planted in two different densities to investigate the growth parameters and the cold tolerance. The stand was measured annually through five growing seasons. The results indicated that the growth difference among the young E. benthamii was noticeable. For example, the maximum and minimum value of five-year old trees at diameter breast height (DBH) was 27.9 centimeters and 1.27 centimeters;and the maximum and minimum value of tree height was 22.86 meters and 2.44 meters, respectively. The yearly change in DBH and height of E. benthamii had significant differences. The average annual survival rates of E. benthamii had differences under the two planting densities (1650 trees ha-1 and 1237 trees ha-1). The densities also had effects on the height and DBH growth of E. benthamii. The average DBH and height of 1650 trees ha-1 plantation were 11.18 centimeters and 15.03 meters, and the average DBH and height of 1237 trees ha-1 plantation were 13.46 centimeters and 16.28 meters. The volume per hectare of 1650 trees ha-1 and 1237 trees ha-1 plantation were 111.45 cubic meters and 101.15 cubic meters, respectively. Average diameter growth was almost 2.54 centimeters per year and average height growth was over 3 meters. E. benthamii plantations were considered tolerant to -7.4 degrees Celsius and a cold spell during early 2014 (-11.3 degrees Celsius for two consecutive nights) killed the plantation. The growth of E. benthamii also varied depending on surrounding conditions. The difference in growth of row seven versus row one was a good example. The reason probably was that row seven was adjacent to a loblolly pine plantation and row one was next to an open field.

Evaluation of Sweet Sorghum as a Feedstock by Multiple Harvests for Sustainable Bioenergy Production

Sweet sorghum has become an important feedstock for bioethanol production. Total sugar yield and multiple harvests can directly affect ethanol production cost. Little is known about stem traits and multiple harvests that contribute to sugar yield in sweet sorghum. Stem traits were evaluated from 25 sweet and grain sorghum accessions. Stems were harvested twice at the soft-dough stage and the stems were pressed with a hydraulic press. Sugars in the stem juice were quantified by high performance liquid chromatography. Sweet sorghum produced five times more fresh stem weight and dry stem mass (830 gand164 g) than grain sorghum (150 gand27g). Sweet sorghum produced a much higher volume of juice and higher yield of sugars (366 ml and42 g) per stem than grain sorghum (70 ml and4 g). Significant variability in fresh stem weight (72 - 1837 g), juice volume (31 - 753 ml), sugar yield (3 - 81 g), dry stem mass (14 - 383 g), and sugar yield/dry stem mass ratio (0.11 - 0.53) per stem was detected among sweet sorghum accessions. Stem sugar yield was significantly correlated with stem fresh weight and juice volume. Sorghum was harvested twice within one growing season resulting in some sweet sorghum accessions producing double amount of sugars. Sweet sorghum produced three times more dry mass weight (bagasse) than fermentable sugar weight. To reduce feedstock cost, methods have to be developed for efficiently utilizing bagasse. Our results showed high fresh stem weight, high ratio of sugar yield to dry stem mass, and double harvests are prime traits to boost sugar yield. Sweet sorghum may be suitable for multiple harvests in certain regions of theU.S.TheU.S.sweet sorghum collection needs to be screened for acces- sions that can be harvested twice with an extended feedstock-production season and used as a feedstock for sustainable and renewable bioenergy production.

Development of the Bioenergy as a Part of Renewable Energy in the Nordic Countries: A Comparative Analysis

A comparative assessment of the bioenergy and renewable energy situation in the Nordic countries, Finland, Sweden, Denmark and Norway, was conducted in this study. What factors have contributed to the current high use of renewable energy and especially bioenergy in the Nordic countries? What are the sources of renewable energy and where renewable energy is being used? The development of renewable energy use is described by time series and compared to the overall development of the EU. All of the Nordic countries have high renewable energy consumption and have already met the target for gross final energy consumption according to the Europe 2020 strategy while the EU is behind the 20% target. In total, 53.1 Mtoe renewable energy was used in the Nordic countries in 2018, which was 51% of the final energy consumption, 103.3 Mtoe. Bioenergy accounts for approximately half of renewable energy, 25.8 Mtoe, and is anticipated to develop further. Especially in Norway and Sweden the share of renewable energy was high (73% and 55%) compared to Finland and Denmark (41% and 36%). Norway is famous for hydropower (81% share of Renewable Energy Sources (RES) in 2018) and Denmark for wind power production (20%), while Finland utilizes a lot of biomass for co-generation and heating (79%), followed by Denmark (64%) and Sweden (55%) in 2018. At EU level, bioenergy plays even a higher role than in Nordic countries in renewable energy production (56%) in 2017 and is anticipated to continue to grow in all end-use sectors such as heating and cooling, electricity generation and transport, in the 2020s.

Land Resource Areas and Spatial Analysis of Potential Location of Bioenergy Crops Production in Mississippi

Mississippi State is renowned for its land resource areas (LRA) and production of bioenergy crops which generate both agricultural and economic benefits. Agricultural commodities play a key role in economic growth, therefore the ability to produce more would enhance development. This paper offers an analysis of the production of bioenergy crops in Mississippi. Relative measures, time series graphs and descriptive statistics coupled with geographic information systems (GIS) mapping using ArcMap were employed to generate the outcome of this research. The outcome of the statistical analysis indicated that corn and soybeans were the most produced crops in Agricultural Districts 10 and 40. These districts produced more bioenergy crops than the other districts. GIS mapping results also showed that the potential area for bioenergy crops is in zone 131 of the Mississippi Land Resource Area (MLRA). This zone has an absolute advantage in the production of these crops which includes the diversity of biomass production such as corn, cotton, soybeans, wheat, rice, barley, grain sorghum, canola, camelina, algae, hardwoods, and softwood. The paper recommends a constant GIS mapping and land management systems for each agricultural district in Mississippi to enable researchers and farmers to determine the factors which contribute towards the increasing and decreasing trends in the production of the bioenergy crops.

Developing sustainable bioenergy in Northwest China

This special focus on bioenergy is a product of 2014 and2016 Yangling International Agri-science Forums held at the Northwest A＆F University（NWAFU）,Yangling,Shaanxi,China.The forums brought together scientists over the world to address the challenges and opportunities of developing bioenergy and bio-based economy in China.

Bridging mapping and simulation modelling in the ecosystem service assessments of boreal forests:effects of bioenergy production on carbon dynamics

Background:Increasing the use of forest harvest residues for bioenergy production reduces greenhouse emissions from the use of fossil fuels.However,it may also reduce carbon stocks and habitats for deadwood dependent species.Consequently,simple tools for assessing the trade-offs of alternative management practices on forest dynamics and their services to people are needed.The objectives of this study were to combine mapping and simulation modelling to investigate the effects of forest management on ecosystem services related to carbon cycle in the case of bioenergy production;and to evaluate the suitability of this approach for assessing ecosystem services at the landscape level.Stand level simulations of forest growth and carbon budget were combined with extensive multi-source forest inventory data across a southern boreal landscape in Finland.Stochastic changes in the stand age class distribution over the study region were simulated to mimic variation in management regimes.Results:The mapping framework produced reasonable estimates of the effects of forest management on a set of key ecosystem service indicators:the annual carbon stocks and fluxes of forest biomass and soil,timber and energy-wood production and the coarse woody litter production over a simulation period 2012–2100.Regular harvesting,affecting the stand age class distribution,was a key driver of the carbon stock changes at a landscape level.Extracting forest harvest residues in the final felling caused carbon loss from litter and soil,particularly with combined aboveground residue and stump harvesting.It also reduced the annual coarse woody litter production,demonstrating negative impacts on deadwood abundance and,consequently,forest biodiversity.Conclusions:The refined mapping framework was suitable for assessing ecosystem services at the landscape level.The procedure contributes to bridging the gap between ecosystem service mapping and detailed simulation modelling in boreal forests.It allows for visualizing ecosystem services as fine resolution maps to support sustainable land use planning.In the future,more detailed models and a wider variety of ecosystem service indicators could be added to develop the method.

Effects of bioenergy production on environmental sustainability:a preliminary study based on expert opinions in Italy and Turkey

In future decades, initiatives on biomass-based energy development in Europe should reduce fossil fuel dependence and help to combat climate change as required by the conference of the parties 21. In this context, forest biomass can play a key role within the bioenergy sector due to its high growth potential. The use of forest biomass for energy has positive and negative effects on other ecosystem services, on stand characteristics, and on forest management practices. The aim of this study is to analyse the effects of forest bioenergy production on six ecosystem services(biodiversity, recreation, landscape aesthetics,carbon sequestration, soil erosion protection, water quality). These effects have been assessed by 80 experts in two countries(Italy and Turkey), considering two different forest management practices(clear-cutting of coppices and woody residue removal after felling in high forests). The results show that coppice clear-cutting has negative effects on almost all ecosystem services according to the experts’ opinions. The highest negative effects are on landscape aesthetics and soil protection. The effects of woody residue removal on biodiversity, carbon sequestration, soil erosion protection, and water quality are considered negative by the experts, while the effects on recreation activities and landscape aesthetics are considered positive. The highest negative effects of this forest management scenario are on soil protection and biodiversity. The experts’ opinions about the effects of forest management practices on ecosystem services can provide information to understand the environmental sustainability of bioenergy development in future years.

Wild melon: a novel non-edible feedstock for bioenergy

In the present research work, a non-edible oil source Cucumis melo var. agrestis （wild melon） was systematically identified and studied for biodiesel production and its characterization. The extracted oil was 29.1% of total dry seed weight. The free fatty acid value of the oil was found to be 0.64%, and the single-step alkaline transesterification method was used for conversion of fatty acids into their respective methyl esters. The maximum conversion efficiency of fatty acids was obtained at 0.4 wt% NaOH （used as catalyst）, 30% （methanol to oil, v/v） methanol amount, 60 ℃ reaction temperature, 600-rpm agitation rate and 60-min reaction time. Under these optimal conditions, the conversion efficiency of fatty acid was 92%. However, in the case of KOH as catalyst, the highest conversion （85%） of fatty acids was obtained at 40% methanol to oil ratio, 1.28 wt% KOH, 60 ℃ reaction temperature, 600-rpm agitation rate and 45 min of reaction time. Qualitatively, biodiesel was characterized through Fourier transform infrared spectroscopy （FFIR） and gas chromatography and mass spectroscopy （GC-MS）. FTIR results demonstrated a strong peak at 1742 cm-1, showing carbonyl groups （C=O） of methyl esters. However, GC-MS results showed the presence of twelve methyl esters comprised of lauric acid, myristic acid, palmitic acid, non-decanoic acid, hexadecanoic acid, octadecadienoic acid and octadecynoic acid. The fuel properties were found to fall within the range recommended by the international biodiesel standard, i.e., American Society of Testing Materials （ASTM）： flash point of 91℃, density of 0.873 kg/L, viscosity of 5.35 cSt, pour point of - 13 ℃, cloud point of -10 ℃, total acid number of 0.242 mg KOH/g and sulfur content of 0.0043 wt%. The present work concluded the potential of wild melon seed oil as excellent non-edible source of bioenergy.