Biomass Energy Production Research Articles

Modeling the evaluation of methods for determining the basic density of wood in forest species based on data from a neuro-fuzzy inference system

The forestry sector is one of the agribusiness sectors that generates the most wealth for the national economy, as it brings benefits to society, from the wood itself for industries, biomass for energy production, and to the environment, reducing pressure on native forests and the reuse of land degraded by agriculture. In view of this, this study was carried out to predict the different basic densities in tree species under the influence of two factors, nine different tree species in relation to three different density methodologies using the Neuro-Fuzzy System. Tree basic density modeling was carried out using effective species parameters and different calculation methodologies adapted to the Neuro-Fuzzy Inference System (ANFIS). In the ANFIS model, 67% and 33% of the total data were considered as training and test data, respectively. The numbers of pertinence functions were selected 9 for species and 3 for methodologies for the input data. ANFIS training was carried out using the hybrid method. The average R2 determination coefficients were 87.32% and 97.42% for the field and ANFIS models, respectively. The model obtained using ANFIS showed a high accuracy of 4.36%. Compared to the field data, the ANFIS model was highly accurate and can be used to estimate the basic density of the trees in this study.

Analysis of Biocharcoal Briquette Characteristics with the Addition of Trembesi (Samanea saman) Dry Leaf Bioadditives

Biocharcoal briquettes are new and renewable biomass energy products. The addition of rain tree leaf bioadaptive to biocharcoal briquettes can increase high carbon compounds. By adding these materials, it can increase the calorific value and produce better energy. The main ingredients in this study were coconut shells, corn cobs, tapioca flour, and betel leaf bioadditives. The research characteristic test was conducted to determine the levels of bound carbon, ash content, volatile matter content, calorific value, and water content. The results showed that the best composition was BBB 4 with a volatile matter content of 0.921%, water content of 2.0%, ash content of 7.9%, calorific value of 5943 cal/g, and bound carbon of 89.179%.

Seaweed waste in eco-friendly construction materials: Valorization of Sargassum ash as a mineral addition in fiber cements

Many coastal regions have recently faced significant challenges due to the excessive accumulation of sargassum. This genus of brown marine algae generates greenhouse gases such as methane and carbon dioxide during decomposition, as well as toxic gases such as hydrogen sulfide and ammonia. The substantial influx of these algae on shores brings far-reaching impacts on the environment, climate, health, and the economy. One way to mitigate these impacts is by using this biomass for energy production and applying the resulting ash as an alternative material in the construction industry. As such, this study aims to analyze the feasibility of sargassum ash as a replacement for limestone in fiber cement. This not only offers an environmentally responsible solution for its disposal, but also adds economic value to a material commonly seen as a waste. Several analyses were conducted on the physical and mechanical properties of fiber cement with varying percentages of limestone replaced by sargassum ash (0, 25, 50, 75, and 100 %), as well as its durability and Life Cycle Assessment (LCA). The fiber cement with 100 % sargassum ash exhibited a 74 % increase in specific energy compared to the fiber cement without the ash after accelerated aging. This mix design also presented better environmental performance in 15 of the 18 impact categories. The results demonstrate that ash holds potential as an alternative material in fiber cement manufacturing.

Cultivation and Potential for Biomass Production for Energy and Seed Purposes of Tall Wheatgrass (Agropyron elongatum (Host) Beauv.) Under Sandy Soil and Temperate Climate Conditions

An experiment was conducted to analyse the potential for obtaining biomass for energy purposes and tall wheatgrass (TWG) seeds grown under conditions of varying pre-sowing fertilisation with compost and mineral fertilisation with nitrogen on sandy soils. Field trials were conducted between 2012 and 2015. The study factors were compost from municipal green areas with I-doses of 0, 10 and 20 Mg∙ha−1 added before sowing and nitrogen II-doses of 0, 40, 80 and 120 kg∙ha−1 added each year in the form of ammonium nitrate. During the experiment conducted on sandy soils, a favourable effect of fertilisation on the morphological parameters of above-ground vegetative and generative parts was found. The experiment resulted in high dry matter yields (DMYs) in the range of 9.08–31.38 Mg∙ha−1 and high seed yields (SYs) (635 kg∙ha−1 to as much as 2397 kg∙ha−1), which depended on the applied fertilisation variant. The applied levels of compost fertilisation had a positive effect on the obtained dry matter yields (DMYs) and SY. Analysing the effect of the applied doses of mineral nitrogen fertilisation (40, 80 and 120 kg∙ha−1) on the dry matter yield of TWG under sandy soil conditions, it should be noted that this factor significantly increased the DMY and SY in all years of the study. At the same time, the response of plants to this factor of the study over the years varied and depended on weather conditions. The high energy yield (192.50 GJ∙ha−1–408.93 GJ∙ha−1) closely related to the high DMY indicates the high suitability of TWG as a new grass species under temperate climate conditions grown for biomass energy production and the possibility to harvest seeds when adequately cultivated.

Atlas of Microscopic Images of Raw Biomass Used in Fuel Production

As nations strive toward achieving sustainability and reducing reliance on fossil fuels, biomass has emerged as an indispensable component of worldwide energy portfolios. Biomass, derived from organic materials such as plants, agricultural residues, forestry byproducts, and organic waste, is a renewable energy source and abundant resource with significant potential across various sectors. Responsible biomass energy production can aid in waste management, reduce greenhouse gas emissions, and mitigate environmental pollution by utilizing organic materials that would otherwise be discarded. With the anticipated growth in biomass use for energy, it is essential to establish analytical techniques for assessing the quality of the fuel feedstock materials. This will enable to better comprehend the implications of using biomass fuels on public health and our ecosystem. One such technique is reflected light microscopy, which has the potential to significantly enhance the conventional (physical and chemical) quality assessment of biomass-derived fuels. This technique enables rapid observations of material constituents and identification of impurities, and it can be applied not only to fuels but also to biomass-based pellets used in animal feed and bedding. Given the scarcity of publicly accessible microscopic images of biomass materials, the “Atlas of Microscopic Images of Raw Biomass” fills this gap by offering a comprehensive collection of 553 images. These photomicrographs capture the optical characteristics of a diverse array of biomass feedstock, demonstrating unique morphological and structural features. This visual documentation can serve as a valuable resource for researchers, industry professionals, educators, and enthusiasts interested in investigating the complexities of biomass forms.

Operational optimization of a rural multi-energy system supported by a joint biomass-solid-waste-energy conversion system and supply chain

Biomass, as one of the most accessible renewable resources, could reduce dependency on fossil fuels and mitigate associated environmental impacts. With economic development and improved living standards, biomass in rural areas is converted into various forms of energy to meet high energy demands. However, existing studies on rural multi-energy system operations assume energy production from biomass is a given input parameter and consider it to be a fixed constant or subject to upper and lower bounds, independent of the biomass supply chain. Indeed, biomass energy production is significantly influenced by the collection, transportation, storage, and other processes within the supply chain. This work proposes a mixed integer linear program (MILP) for the joint optimization of an integrated rural multi-biomass-solid waste energy conversion system with a source-grid-demand-based biomass-solid waste supply chain (IRMBS-BSC system). The IRMBS-BSC system encompasses three sub-systems: the biomass-solid waste source sub-system, the biomass-solid waste grid sub-system, and the biomass-solid waste demand sub-system. Various biomass-solid wastes are classified, and a source model is established to evaluate their availability. Subsequently, a supply chain model is developed within the biomass-solid waste grid sub-system. Based on the available and transported quantity from the biomass-solid waste source sub-system and grid sub-system, a multi-energy system operation model, considering refined biomass conversion processes, is proposed. A case study involving a multi-energy system that integrates multiple rural community biomass-solid waste supplies is conducted. The results demonstrate that the proposed MILP, which considers the biomass-solid waste supply chain, can reduce energy imports during the load peak periods and can also decrease the overall operational costs of the multi-energy system.

Comprehensive Analysis of Miscanthus Research: Sustainable Biomass and Bioenergy Through Knowledge Mapping

Miscanthus grass species have gained global research attention in the fields of biomass and bioenergy, witnessing remarkable advancements in the 21st century. This study systematically searched and selected relevant literature on primary research involving Miscanthus species, published between 2007 and 2023, from the China National Knowledge Infrastructure and Web of Science core databases. Utilizing CiteSpace as a bibliometric tool, the study generated quantitative statistics and performed data analysis on the selected articles. The examination covered publication trends, national and author publication outputs, author and journal co-citations, keyword research hotspots, and the temporal evolution of research topics in the Miscanthus research field, offering empirical support for future in-depth investigations and innovation in Miscanthus spp. The research findings reveal the following insights: (1) Publication trends can be divided into two phases (stable growth and fluctuating decline), with recent trends maintaining a relatively high level. (2) A collaborative publication network, led by core authors such as Zili Yi, John Clifton-Brown, and Iris Lewandowski, has been established, characterized by a diverse research focus and close cooperation. (3) Research hotspots encompass several aspects, including biomass production yield, efficiency, and energy products of Miscanthus spp., ecological restoration, genetics, plant physiological research, and chemical components. The primary species investigated are Miscanthus×giganteus, Miscanthus sinensis, Miscanthus floridulus, and Miscanthus lutarioriparius.

Assessment of Bioenergy Potential in Vindhya Plateau, Madhya Pradesh

Evaluating agricultural residue availability is crucial for assessing sustainable biomass energy production. Crop waste, a byproduct of agricultural production, can be used for soil amendment, animal feed, and energy generation. A survey in seven districts of central India (Bhopal, Damoh, Guna, Raisen, Sagar, Sehore, and Vidisha) was conducted to assess the availability of agricultural residue in the Vindhya Plateau, which comprises about 16% of Madhya Pradesh's geographical area. Agricultural residue availability was determined by selecting a crop, gathering data on yield and generated biomass (including surplus), and estimating the bioenergy potential. The cultivable areas in the selected districts have bioenergy potentials of 19.91, 15.19, 7.88, 21.89, 13.71, 15.09, and 17.21 kJ ha-1 for crops like soybean, rice, wheat, gram, and maize, respectively. The total residue potential, surplus residue potential, and bioenergy potential of the Vindhya Plateau were assessed as 6.08 MT, 2.42 MT, and 40 GJ, respectively. Vindhya Plateau's Raisen district offers the highest biomass potential, making it ideal for bioenergy development and fuel production from biomass.

Optimizing biomass energy production in the southern region of Iran: A deterministic MCDM and machine learning approach in GIS

This study employs a deterministic approach, distinguishing itself from other renewable energy evaluations, to assess the potential of electrical energy derived from biomass sources in the southern region of Iran. The primary objectives include pinpointing optimal locations for maximal biomass production and subsequent energy generation within distinct climates and topographies, using fuzzy- Analytic Hierarchy Process (AHP). Additionally, Principal Component Analysis (PCA) identify key factors influencing biomass and energy production. The study quantifies electrical and thermal energy derived from biomass sources across various climates. The findings indicate that regions with lower altitudes and humid climates (1530 km2) demonstrate superior biomass performance, leading to increased electrical and thermal energy production. The feature selection process highlights the significant impact of climate and soil characteristics on biomass production and energy output. Analysis of biomass energy production reveals maximum electrical energy production ranging from 674.88 kWh/ha to 711.36 kWh/ha. The results of the Long Short-Term Memory (LSTM) method confirm its high accuracy in estimating electrical energy, with a significant correlation coefficient of 0.98. We conclude that by identifying locations with the best biomass sources based on climate, it is possible to increase the derived electrical energy. These insights are critical for informing energy policies aimed at optimizing biomass energy production and its integration into sustainable power grids.

Characterization of Fuel Pellets Made From Rice Husk, Sawdust and Corncob Bond with Cissus Populnea and Manihot Esculenta

There is growing interest in the production of biofuels from biomass wastes. The availability of biomass waste poses the need for technical assessment of pelletisation of biomass waste at industrial production level. The misuse of environmentally friendly and sustainable energy resources and lack of compressed biomass energy products that could enhance fuel quality needs to be addressed. This study intends to determine the energy output from tenary combination of the biomass fuel pellets consisting of rice husks, African birch sawdust, corncobs and their varying mixtures bond with aqueous extract of C. populnea (Cp) and M. esculenta (Me). The combustion characteristics of pellets produced from Rice Husk, African Birch Sawdust, Corncob and their blends (M, M1, M2, M3 and M4) were conducted by the development of an analytical protocol. Pellet admixtures were prepared at each binder ratio of 10% of bulk weight of RH, ABS, corncob and their various blends in the ratios 1:1:1 (M), 1:2:3 (M1), 2:1:3 (M2), 3:1:2 (M3) and 2:3:1 (M4), respectively. The Bulk Density (BD), Ash Contents (AC), Heat Release Rate (HRR) and Calorific Value (CV) of the pellets were measured using established procedures. The result revealed that combustion characteristics of fuel pellets made from Corncob and Blend ratio of 1:2:3 bound with Manihot esculenta gel were enhanced and the fuel pellets possessed sufficient calorific values suitable for energy applications. It was recommended that massive production of fuel pellets from biomass wastes for small and medium scale energy systems could give a positive development to agrarian and rural areas in Nigeria where there is a lot of these resources and lack of stable electrical supply.

Developing biomass energy from agricultural by-products in the context of trade development

With global trade development, emerging economies can absorb biomass energy production techniques and technologies from developed countries. However, several constraints still need to be improved in producing biomass energy in emerging economies. Therefore, this research aims to understand the critical motivating factors of biomass energy production that contribute to a circular economy via agricultural by-products in Vietnam's emerging economy. This study employs a qualitative analysis using information from the in-depth interviews of farmer households, agricultural by-product traders, and bioenergy producers in Vietnam. This study revealed the motivating factors as the main determinants in producing biomass energy: (1) digitalization, (2) technical and logistics, (3) social capital, (4) prices, and (5) government supports. This study also confirms that Vietnam has diverse biomass waste sources and a high potential for biomass energy production. To motivate biomass energy development, the government should support credit and loans for stakeholders in producing biomass energy. Moreover, the government should encourage and support energy producers to implement digital transformation to expand production scale and improve business operations. Insights from this study can help farmers, traders, and bioenergy producers by adapting their strategies within their local contexts.

Sustainability of Alternative Energy Sources: Thermo-Gravimetric Analysis of Energy Crops in Ekiti State, Nigeria

Ekiti State is a farming region with the ability to produce biomass reserves, which include yet refined crop cultivation product leftovers like sugar cane, corn cobs, palm husk shells, and okanagan wood, for use as fuel. The vast energy-generating potential of crops for use in industry and household applications is examined in this article. Biomass crops were subjected to a thermogravimetric examination to determine their unique thermal activity in an airtight and benign atmosphere with a temperature increase of 10°C per minute up to 800°C. The decrease in weight pattern was shown to be similar across all four waste specimens. Three reactive regions were identified during the nitrogen-rich environment assessment, which correlate to water loss, flammable generation, and char breakdown. Three response domains in an air system corresponded to the degradation, burning, and drying of char. The proximate and ultimate evaluation outcomes demonstrated that each of the bioenergy crop leftovers under investigation is fit for gas extraction and fuel combustion to meet power and thermal needs. The computational and experimental analysis revealed that Okanagan wood has the highest calorific value which indicates the highest heat values and considered the best for biomass energy production in Ekiti State for entrepreneurial venture.

Integrated partial nitrification and Tribonema minus cultivation for cost-effective ammonia recovery and lipid production from slaughterhouse wastewater

High ammonium content in untreated anaerobic digestion (AD) wastewater can inhibit microalgal growth, hindering both bioremediation and biomass/lipid productivity. This study investigated the potential of partial nitrification (PN) as a pretreatment step for AD effluent before cultivating the oleaginous microalga Tribonema minus for bioremediation and lipid production. The PN process transforms inhibitory ammonium into nitrate, a nitrogen form that microalgae can effectively utilize, thereby reducing ammonia toxicity. The results showed remarkable resilience in T. minus, with the species being able to tolerate high ammonium levels (≤120 mg/L) when combined with nitrate in synthetic wastewater. However, when ammonium was the sole nitrogen source (>30 mg/L), its inhibitory effect on T. minus growth became evident. Nevertheless, successful cultivation of T. minus was achieved in PN effluent from slaughterhouse AD using a Sequencing Batch Reactor (SBR) (25 °C and hydraulic retention time (HRT) of 1.5 h) containing 190 mg/L ammonium, achieving 51.25 % lipid accumulation. Additionally, cultivation with 125 mg/L NH4+-N in the PN effluent resulted in removal rates exceeding 95 % for NH4+-N. This approach, therefore, delivered the dual advantage of not only mitigating the environmental risks associated with wastewater but also fostering renewable biomass production for cleaner energy.

Biohydrogen production by a novel strain Petroclostridium sp. X23 isolated from the production water of oil reservoirs

Biohydrogen production from H2-producing has been considered a promising alternative for the replacement of fossil fuels. However, the mechanisms that affect the H2-producing capacities of wild-type strains remain largely elusive. To explore the capabilities of biohydrogen production from microorganisms in the deep subsurface oil-reservoir environment, we isolated an H2-producing bacteria identified as the genus Petroclostridium from a long-term methanogenic crude oil-degrading enrichment culture of the production water from oil reservoir. The impact of various temperature, pH, and glucose concentrations on hydrogen production by Petroclostridium sp. X23 was investigated. Under the conditions of 37 °C, initial pH 8.0, and glucose concentration of 4 g/L, the strain X23 achieved its maximum hydrogen yield at 1.82 ± 0.12 mol H2/mol glucose. When compared to the previously reported strain SK-Y3, X23 exhibited enhanced H2-producing ability, with lesser energy biomass production. Comparative genomic analysis revealed that the genome of X23 contains more genes associated with hydrogen generation than SK-Y3. These findings proposed Petroclostridium sp. X23 is a potential candidate for dark fermentative hydrogen production under alkaline and mesophilic conditions. It also increased our knowledge of genotypes related to high H2-producing capability, which may provide instructions for future selection of high-yielding strains and reasonable metabolic engineering of wild-type H2-producing strains.

A novel additive for enhancing biomass energy production from agro-industrial wastes: synthesis of hydrophobic nanoporous silica aerogel and its effect on methane production

AbstractAnaerobic digestion (AD) is one of the most preferred processes for the treatment of organic waste. However, additional processes such as co-digestion, pretreatment, and additive addition continue to be explored to remove the limits on the applicability of AD. This study investigated the effects of hydrophobic nanoporous silica aerogel (NpSA) synthesized from waste rice husks on the anaerobic co-digestion (AnCD) of the mixture consisting of sewage sludge and fruit processing industry wastes. All bioreactors containing NpSA-free, 0.1 g, 0.2 g, 0.5 g, and 1 g NpSA (0.03–0.3 gNpSA/gVSadded) were operated in a mesophilic-batch process. Biogas and methane yields increased from 346 mL/gVS (NpSA-free) to 387 mL/gVS and from 231 mL/gVS (NpSA-free) to 288 mL/gVS, respectively, with 0.1 g NpSA addition. NpSA additive increased biogas production in all bioreactors compared to the blank. However, biogas production rate and methane content increased faster at lower doses of NpSA. Maximum soluble chemical oxygen demand (sCOD), protein, carbohydrate, and volatile solid (VS) reductions were between 45–71%, 35–54%, 44–65%, and 34–91% for NpSA added mixtures, respectively. The hydrophobic NpSA additive was effective in improving the AnCD performance and biogas/methane production. Experimental results fit the kinetic models frequently preferred in such AD processes. In addition, the possible energy and financial potential of the produced methane were also discussed, and it was determined that the direct sale of methane gas produced by the addition of NpSA in the global market could provide 1.4 $/Lmixture more financial gain than the mixture NpSA-free. Graphical Abstract

Development and performance assessment of a novel multigeneration clean energy system based on biomass-LNG using a dynamic model and supervised learning algorithms

Combining process integration mechanisms with artificial intelligence (AI) can be used as a tool for maximum use of biomass capacity and energy production. This study proposes a continuous multi-generation hybrid energy production system based on biomass-LNG using the carbon capture, utilization, and storage (CCUS) method. In this system, using the Gibbs free energy minimization approach, a process based on the fluidized bed gasifier was designed, which in addition to producing hydrogen and electricity from biomass, also produces liquid CO2 and precipitated calcium carbonate (PCC) from liquid natural gas and limestone for the first time. This process was also examined from thermal (HHV) and thermodynamic (Exergy) standpoints. The simulation of the gasification unit was able to predict the percentage of exhaust gases from the gasifier with errors of RMSE = 3.8 and RMSE = 3.2 for almond shell and rice shell biomass, respectively. Following that, a dataset with more than 14 million records was generated. Then, machine learning methods were employed to investigate and improve the process's simulation characteristics. The evaluation of 15 machine learning algorithms in the construction of the predictive model showed that ANN, Extra Tree Regressor, and Random Forest are the most accurate algorithms in predicting the desired values (such as hydrogen, work, PCC, liquid CO2, exergy, and HHV) with R2 > 0.99. The dataset analysis showed that the current process could produce 130 kg/h of hydrogen, 375 kWh of work, 2600 kg/h of PCC, and 531 kg/h of liquid carbon dioxide on average. As a final step, a WPF desktop application was developed that simplifies the use of ML models so that the impact of changing the variables can easily be calculated.

Introducing Gliricidia sepium as a Fuel Wood in Rubber Smallholdings of Sri Lanka: A Case Study in Kalutara District


 A pilot project has been initiated to introduce Gliricidia sepium with Hevea brasiliensis under three different spatial arrangements ((i.)8'×27', (ii.)8'×40, and (iii.)88'×60’) as a fuel wood to improve the income status of rubber smallholders in Kalutara District by Rubber Research Institute of Sri Lanka in 2018. Primary data were collected through a questionnaire survey and field observations. The financial analysis was done for one hectare of smallholding. Certain assumptions were made in the financial feasibility analysis as financial analysis was done for 30 years giving consideration to the 30 year life span of rubber. Costs and benefits were discounted at 10% discount rate as practiced by the Department of National Planning to obtain 2019 market prices. The farm gate prices of 1kg of rubber and Gliricidia were considered as LKR 280.00 and LKR 4.00. The cost for hired labour was considered LKR 1,500.00 per day. Period of intercropping of Gliricida under rubber in the 88'×40' and 88'×60' models was considered as 30 years and in the 88'×27' model, it was considered as eight years. Financial feasibility of models was tested using the indices of Net Present Value (NPV) and Benefit Cost Ratio (BCR). A qualitative SWOT was conducted to identify the strengths, weaknesses, opportunities and threats relevant to introduction of Gliricidia as an intercrop in rubber plantations based on a thorough documentation review and on the opinions of Rubber Extension Officers. From the three models introduced, the highest fuel wood value can be obtained by intercropping Gliricidia with rubber under the spacing of 88'×60'. NPV for growing gliricidia with rubber under three different spatial arrangements, (i.)88'×27', (ii.)88'×40' and (iii.)88'×60' would be LKR 0.74 million, LKR 5.47 million and LKR 5.89 million respectively. The values obtain for BCR for growing gliricidia with rubber under three different spatial arrangements, (i.)88'×27', (ii.)88'×40' and (iii.)88'×60' would be 1.37, 2.26 and 2.27, respectively. All fuel wood growing models indicated positive NPV and BC Ratios were greater than one, suggesting that these introduced models are economically viable. Although there are no established market channels available for fuel wood especially in the smallholder rubber sector of Sri Lanka, there is a demand for Gliricidia which is fulfilled through adhoc markets. Also, development of sustainable supply chains through setting up of Pilot Biomass Energy Terminals with the objective of collection and distribution of fuel wood under the Project of Promoting Sustainable Biomass Energy Production and Modern Bio-Energy Technologies has widened the opportunity of using Gliricidia as a promising fuel wood species Gliricidia with rubber has the potential to improve income generation of rubber smallholders substantially especially during the immature stage of rubber and provide a solution to overcome uncertainty in rubber prices and low productivity of rubber lands.
 
 Keywords: Fuel wood growing models, Rubber farming

Net carbon sequestration implications of intensified timber harvest in Northeastern U.S. forests

AbstractU.S. forests, particularly in the eastern states, provide an important offset to greenhouse gas (GHG) emissions. Some have proposed that forest‐based natural climate solutions can be strengthened via a number of strategies, including increases in the production of forest biomass energy. We used output from a forest dynamics model (SORTIE‐ND) in combination with a GHG accounting tool (ForGATE) to estimate the carbon consequences of current and intensified timber harvest regimes in the Northeastern United States. We considered a range of carbon pools including forest ecosystem pools, forest product pools, and waste pools, along with different scenarios of feedstock production for biomass energy. The business‐as‐usual (BAU) scenario, which represents current harvest practices derived from the analysis of U.S. Forest Service Forest Inventory and Analysis data, sequestered more net CO2 equivalents than any of the intensified harvest and feedstock utilization scenarios over the next decade, the most important time period for combatting climate change. Increasing the intensity of timber harvest increased total emissions and reduced landscape average forest carbon stocks, resulting in reduced net carbon sequestration relative to current harvest regimes. Net carbon sequestration “parity points,” where the regional cumulative net carbon sequestration from alternate intensified harvest scenarios converge with and then exceed the BAU baseline, ranged from 12 to 40 years. A “no harvest” scenario provides an estimate of an upper bound on forest carbon sequestration in the region given the expected successional dynamics of the region's forests but ignores leakage. Regional net carbon sequestration is primarily influenced by (1) the harvest regime and amount of forest biomass removal, (2) the degree to which bioenergy displaces fossil fuel use, and (3) the proportion of biomass diverted to energy feedstocks versus wood products.

Catch and Cover Crops’ Use in the Energy Sector via Conversion into Biogas—Potential Benefits and Disadvantages

The development of civilization is related to an increase in energy demand, while its production is still based mainly on fossil fuels. The release of carbon into the environment, which disturbs the balance of the global system, is the consequence of using these fuels. One possible way to reduce the carbon footprint of the energy sector is the widespread use of cover crops’ biomass for energy production. The aim of this paper is to critically review the knowledge on the dissemination of catch and cover crops’ cultivation in different regions of the world, and the yield, chemical composition and biomethane potential of their biomass. Additionally, the environmental benefits, as well as the challenges and opportunities associated with this biomass use in the energy sector, are considered. The review showed that the aboveground biomass of cover and catch crops is a valuable source for the production of bioenergy in biogas plants. However, the key role of these crops is to prevent soil degradation. Therefore, changes in biomass target use must be preceded by a multi-aspect analysis that allows their impact on the environment to be assessed.

Planning biomass energy production in a farming area

A thorough analysis of biomass supply and of energy demand should be carried out at local scale in order to optimize bioenergy plans and deal with the related social ad environmental issues. We present a method to identify the optimal use of biomass: local biomass availability is assessed, the road network is used to evaluate transportation costs, and different energy conversion technologies are considered. Energy crops and animal slurries are considered as feedstocks. We also estimate the amount of land available for energy crops, given the current land use. The comparison between possible conversion systems is carried out solving an optimization problem for the net energy produced in the system, accounting for energy needs for biomass cultivation, collection, and transportation. An emissive indicator is used to evaluate the amount of carbon equivalent emissions avoided. The economic performance of the systems is also analysed. The method is applied to the province of Ravenna in Italy. Transport and cultivation energy and emissions are much smaller than the energy produced or the emissions avoided. The biomass transformation chain can indeed provide 1.9-3.3% of the present power consumption and may reduce GHG emissions by 1-3.5% by replacing fossil fuels.