Harnessing methane generated from livestock manure in Ghana, Nigeria, Mali and Burkina Faso

Methane emission from livestock manure is increasingly contributing to the global green house gas emissions. In this paper the methane emission from cattle, pig, sheep, goat and chicken manure in four West African countries; Nigeria, Ghana, Burkina Faso and Mali were estimated. A systematic estimation of the methane emission was done based on the livestock production projections by FAO from 1998 to 2008 and guidelines provided by the Intergovernmental Panel on Climate Change (IPCC). During this period, cattle were found to have emitted more methane followed by pigs, goats, sheep and chicken in that order. A total of about 845 Gg of methane was emitted by the livestock during the period of which cattle contributed about 40%, whereas pigs, goats, sheep and chicken contributed 21.2%, 18.7%, 13.1% and 6.6% respectively. The methane emission from manure management in these countries increased from 64.1 Gg in 1998 to 90.5 Gg in 2008, with an annual growth rate of 3.4% y⁻¹. The methane estimated from livestock manure over the period was shown to be consistent with the linear group model which predicts that in 2018, 2.4 Mt CO₂-eq will be emitted increasing to 3.0 Mt CO₂-eq in 2028 if the mechanism of manure management remains unchanged. This paper reveals that generating methane from the manure produced by the livestock under controlled conditions could supplement the energy needs, increase Gross Domestic Product (GDP) and consequently reduce the direct impact of methane on climate change.     

A comparison of the drivers influencing adoption of on-farm anaerobic digestion in Germany and Australia

This review examines the drivers behind the adoption of on-farm anaerobic digestion in Germany where there were more than 4000 plants operating in 2009. In Australia, only one plant is operating, at a piggery in the State of Victoria. Germany’s generous feed-in-tariffs for renewable energy are typically given the credit for promoting investment in on-farm anaerobic digestion. But the particular biophysical and socio-economic character of farming in the country provided the fertile ground for these financial incentives to take root. Energy security has also been a major driver for the promotion of renewable energy in Germany since it imports over 60% of its energy needs. In contrast, Australia is a net energy exporter, exporting about two-thirds of its domestic energy. Although it has considerable potential for application in Australia, anaerobic digestion is unlikely to be widely adopted unless new incentives emerge to strongly encourage investment. Stronger Australian regulation of manures and effluent may serve as an incentive to a limited extent in the future. Yet the experience in Germany suggests that regulation on its own was not sufficient to encourage large numbers of farmers to invest in anaerobic digestion. Even with generous incentives from the German government, increasing construction costs and the rising cost of energy crops can put the financial viability of anaerobic digestion plants at risk. Unless improvements in efficiency are found and implemented, these pressures could lead to unsustainable rises in the cost of the incentive schemes that underpin the development of renewable energy technologies.     

Standalone hybrid system energy management optimization for remote village considering methane production from livestock manure

Recently, many efforts have been done to overcome increasing fuel consumption. One of the vital solutions is utilization of standalone renewable energy resources hybrid systems. This paper attempts to develop a cost-effective methodology to ascertain optimal design and energy management for a remote village. Different energy resources such as wind and solar, fuel cell, and energy storage systems are employed to satisfy total demands including agriculture, residential, school, and health center. Different hydrogen production methods are proposed to verify the efficiency of the developed methodology. In the proposed village, different waste types such as rice husk, maize straw, livestock, and residential wastes are used to generate the required hydrogen for fuel cells to generate electricity. The main objective of the proposed methodology is minimizing the total cost of the village including total costs of each Distributed Generation (DG), cost of natural gas consumption, penalty for interruption the demands, and cost of CO₂ emission. A Particle Swarm Optimization (PSO) algorithm is employed to solve the optimization problem by minimizing the total system costs while the customers required Loss of Power Supply Probability (LPSP) is satisfied. The suggested hybrid system not only increases the renewable energy penetration but also decreases the natural gas consumption. The results achieved in the course of the present study depict that utilization of energy produced from different types of wastes plays a significant role in conserving fossil fuels and overcoming the fossil fuels depletion. It is concluded from the results that there is about a 17.46% reduction in natural gas consumption when all available waste is utilized. In addition, considering 100% availability for the animal manure reduces the natural gas consumption by reformer from 2.373 to 1.605 million liters which means reduction of the natural gas consumption is 32.35%. The results conclude that H₂ produced by livestock waste is dominating among available wastes. However, there is about 18% reduction in the Cost of Energy (COE), when 100% availability is considered for this type of waste.     

Co-digestion of swine manure and corn stover for bioenergy production in MixAlco™ consolidated bioprocessing

MixAlco™ consolidated bioprocessing (CBP) employs a mixed culture of terrestrial microorganisms to anaerobically ferment waste streams (e.g., animal manure, agriculture residues) into mixed carboxylate salts that can be further chemically converted to commodity chemicals (e.g., acetic acid, acetone) and liquid transportation fuels (e.g., ethanol, mixed alcohols, bio-gasoline). For countercurrent fermentations of 60% swine manure/40% lime-treated corn stover at 55 °C, the highest acid productivity [1.8 g/(L·d)] and highest conversion (73%) in this study occurred at an acid concentration of 25.1 and 17.0 g/L, respectively. The continuum particle distribution model (CPDM) predicted the experimental total acid concentrations and conversions around 11.1% and 17.2%, respectively. The CPDM prediction "map" for MixAlco™ CBP indicates that both high conversions (>79%) and high total acid concentrations (>35 g/L) are possible at industrial scale. The present study shows continuous co-digestion of corn stove and swine manure in the MixAlco™ process has the potential to produce annually 9.3 billion gallons of alcohol fuels (e.g., ethanol and mixed alcohols) in the United States.     

Potential for biofuels from the biomass of prickly pear cladodes: Challenges for bioethanol and biogas production in dry areas

Prickly pear is a term used to refer to several species of cactus belonging primarily to the genus Opuntia. In general, these species present an exceptional ability to produce biomass in soil and climate conditions unfavorable for most plant species, in part due to their high water use efficiency. Given the current increase demand for renewable energy and the future prospect of more limited water resources, the potential use of prickly pear cladodes for biofuel production deserves to be investigated. The objectives of this study were to gather information on the chemical composition of prickly pear biomass from the most cultivated varieties in NE Brazil, discuss the potential of processing biomass for ethanol and biogas production and to point out gaps in know-how and priorities for research on this topic. We quantified in the tree varieties studied significant amounts of uronic acids (10.7%) and oxalic acid (10.3%), confirming the reports of high amounts of pectin and calcium oxalate in cladodes of prickly pear. The estimated potential of ethanol production for prickly pear (1490–1875 L ha⁻¹ yr⁻¹) was low when compared to traditional biomass sources (sugarcane and sugar beet, for example). However, it appears that prickly pear stands out as a biomass with potential for high production rates of methane (3717 m³ ha⁻¹ yr⁻¹), being comparable to traditional energy crops. Further studies are needed to assess more consistently both the sustainability of biomass production as the potential for ethanol, and biogas production, specially for newly released varieties of prickly pear.     

Physiochemical characterization and thermal kinetics of lignin recovered from sustainable agrowaste for bioenergy applications

In this study, lignin, one of the commonly occurring natural polymers, is extracted from banana agro-waste. Lignin is recovered from the spent liquor produced during alkaline pre-treatment of agro-waste and precipitated by acidification. This study focuses on the physio-chemical characterization and thermal degradation behaviour of lignin extracted from agro-waste biomass. The extracted lignin yield accounts for nearly 12% of the biomass composition. Spectral analysis, FTIR and NMR explain purity and carbon skeleton characteristics of herbaceous lignin monomers, majorly G and S units. Morphological analysis by SEM showed hollow spherical structures with large surface area for the extracted lignin. The calorific value of extracted lignin was experimentally found to be 21.4276 MJ/kg, which suggests the possible use of extracted lignin as an alternative to sub-bituminous coal. Thermal studies of lignin showed that lignin degrades in a wide temperature range releasing CO₂, CH₄, H₂O, CO and H₂. The volatile content of extracted lignin is found to be 31.42%, which suggests its possibility for gasification process. The overall outcome supported that recovered lignin from agro-waste is a potential resource for bioenergy.     

Striving to further harmonization of sustainability criteria for bioenergy in Europe: Recommendations from a stakeholder questionnaire

This questionnaire analyzed the ongoing development of sustainability criteria for solid and liquid bioenergy in the European Union and further actions needed to come to a harmonization of certification systems, based on EU stakeholder views. The questionnaire, online from February to August 2009, received 473 responses collected from 25 EU member countries and 9 non-European countries; 285 could be used for further processing. A large majority of all stakeholders (81%) indicated that a harmonized certification system for biomass and bioenergy is needed, albeit some limitations. Amongst them, there is agreement that (i) a criterion on ‘minimization of GHG emissions’ should be included in a certification system for biomass and bioenergy, (ii) criteria on optimization of energy and on water conservation are considered of high relevance, (iii) the large variety of geographical areas, crops, residues, production processes and end-uses limits development towards a harmonized certification system for sustainable biomass and bioenergy in Europe, (iv) making better use of existing certification systems and standards improves further development of a harmonized European biomass and bioenergy sustainability certification system and (v) it is important to link a European certification system to international declarations and to expand such a system to other world regions.     

An analysis of used lubricant recycling, energy utilization and its environmental benefit in Taiwan

Utilizing used lubricants as energy sources has been currently demonstrated to be one of the best available waste management methods. In this regard, used lubricants for use as energy sources in Taiwan thus became popular in recent years. The objective of this study was to present a comprehensive analysis of used lubricant-to-energy in Taiwan, which includes status of lubricant consumption, and used lubricant generation and its recycling (i.e., collection & treatment) management system. It was found that a major market for utilizing used lubricants in Taiwan (over 90%) was reused as fuel oils or auxiliary fuels in the cogeneration system. Under the regulatory authorization of the Waste Management Act and the Petroleum Administration Act, the central competent authorities encouraged the energy-intensive industries in the waste-to-energy through the excess electricity purchase and subsidiary incentives. Based on the certified volume of collected used lubricant and its energy use proportion in 2009, the total energy potential and the environmental benefit of mitigating CO₂ emissions in place of fuel oils were preliminarily calculated to be around 9.4 × 10² TJ and 7.3 × 10⁷ kg, respectively.     

Present and prospective role of bioenergy in regional energy system

Bioenergy is the energy released from the reaction of organic carbon material with oxygen. The organic material derived from plants and animals is also referred to as biomass. Biomass is a flexible feedstock capable of conversion into solid, liquid and gaseous fuels by chemical and biological processes. These intermediate biofuels (such as methane gas, ethanol, charcoal) can be substituted for fossil based fuels. Wood and charcoal are important as household fuels and for small scale industries such as brick making, cashew processing etc. The scarcity of biofuels has far reaching implications on the environment. Hence, expansion of bioenergy systems could be influential in bettering both the socio-economic condition and the environment of the region. This paper examines the present role of biomass in the region’s (Uttara Kannada District, Karnataka State, India) energy supply and calculates the potential for future biomass provision and scope for conversion to both modern and traditional fuels. Based on the detailed investigation of biomass resource availability and demand, we can categorise the Uttara Kannada District into two zones (a) Biomass surplus zone consisting of Taluks mainly from hilly area (b) Biomass deficit zone, consisting of thickly populated coastal Taluks such as Bhatkal, Kumta, Ankola, Honnavar and Karwar. Fuel wood is mainly used for cooking and horticulture residues from coconut, arecanut trees are used for water heating purposes. Most of the households in this region still use traditional stoves where efficiency is less than 10%. The present inefficient fuel consumption could be brought down by the usage of fuel efficient stoves (a saving of the order of 27%). Availability of animal residues for biogas generation in Sirsi, Siddapur, Yellapur Taluks gives a viable alternative for cooking, lighting fuel and a useful fertiliser. However to support the present livestock population, fodder from agricultural residues is insufficient in these Taluks. There is a need to supplement the fodder availability with fodder crops as successfully tried in Banavasi village by some progressive farmers.     

Sustainability trade-offs in bioenergy development in the Philippines: An application of conjoint analysis

Sustainability assessments of bioenergy production are essential because it can have both positive and negative impacts on society. Human preferences that influence trade-off decisions on the relevant determinants and indicators of sustainability should be taken into account in these assessments. In this paper, we conducted a survey with five groups of respondents including government officials and employees, academic and research professionals, private company managers and workers, farm owners and workers, and others (e.g. students, residents, etc.) to assess their trade-off decisions on bioenergy development in the Philippines. The analyses of the survey results reveal that sustainability of bioenergy production will depend on the choice of biomass feedstock and these choices depend on people's perceptions. Heterogeneous perceptions among the different groups of respondents on the appropriate bioenergy feedstock to achieve economic, social and ecological sustainability suggest that sustainability of bioenergy is not a generic concept. The use of aggregate indices for sustainability assessments that ignore these perceptions on bioenergy production can thus be very misleading. The preference weights from conjoint analysis, which measure human preferences on different determinants and indicators of economic, social and ecological sustainability, can help improve sustainability assessments.     

Estimation of methane and nitrous oxide emission from livestock and poultry in China during 1949–2003

To investigate the greenhouse gases emission from enteric fermentation and manure management of livestock and poultry industry in China, the present study presents a systematic estimation of methane and nitrous oxide emission during 1949–2003, based on the local measurement and IPCC guidelines. As far as greenhouse gases emittion is concerned among livestock swine is found to hold major position followed by goat and sheep, while among poultry chicken has the major place and is followed by duck and geese. Methane emission from enteric fermentation is estimated to have increased from 3.04 Tg in 1949 to 10.13 Tg in 2003, an averaged annual growth rate of 2.2%, and methane emission from manure management has increased from 0.16 Tg in 1949 to 1.06 Tg in 2003, an annual growth rate of 3.5%, while nitrous oxide emission from manure management has increased from 47.76 to 241.2 Gg in 2003, with an annual growth rate of 3.0%. The total greenhouse gas emission has increased from 82.01 Tg CO₂ Eq. in 1949 to 309.76 Tg CO₂ Eq. in 2003, an annual growth rate of 2.4%. The estimation of livestock methane and nitrous oxide emissions in China from 1949 to 2003 is shown to be consistent with a linear growth model, and the reduction of greenhouse gas emission is thus considered an urgent and arduous task for the Chinese livestock industry.     

A management tool for estimating bioenergy production and carbon sequestration in Eucalyptus globulus and Eucalyptus nitens grown as short rotation woody crops in north-west Spain

This study proposes stand level models for estimating biomass yield, total energy and carbon sequestration in Eucalyptus globulus and Eucalyptus nitens plantations, on the basis of measurements made in 131 plots established at the usual range of initial forest densities for southwestern Europe. The timber volume, total aboveground biomass, logging residue biomass, crown biomass, carbon in aboveground biomass and soil organic layer, energy in aboveground biomass, energy in logging residue biomass and usable cellulose yield were represented in the form of isolines (taking mortality into account) and plotted against dominant height. These variables were calculated and compared with previously published data on two silvicultural options for short rotation forestry, one destined for bioenergy production and the other consisting of the standard silviculture regime applied to both species in southern Europe, considering the average site index for each species. Yield levels were higher in E. nitens than in E. globulus for all variables because of faster diameter increment at similar densities. The total yield in terms of biomass was 13.9-14.6 Mg ha⁻¹ y⁻¹ for E. globulus and 20.4-21.5 Mg ha⁻¹ y⁻¹ for E. nitens. Energy in aboveground biomass ranged between 233 and 245 GJ ha⁻¹ y⁻¹ for E. globulus and 345 and 364 GJ ha⁻¹ y⁻¹ for E. nitens, carbon accumulation rate in aboveground biomass and soil organic layer was 6.9-7.2 Mg ha⁻¹ y⁻¹ for E. globulus and 12.7-13.5 Mg ha⁻¹ y⁻¹ for E. nitens, and usable cellulose was 5.7-5.9 Mg ha⁻¹ y⁻¹ for E. globulus and 9.0-10.1 Mg ha⁻¹ y⁻¹ for E. nitens. It was found that 50% increments in the initial density result in only marginal increments in biomass and usable cellulose yields.     

A GIS-based approach for evaluating the potential of biogas production from livestock manure and crops at a regional scale: A case study for the Kujawsko-Pomorskie Voivodeship

In Poland, the promotion of the development of biogas plants was intensified under legal regulations. The potential expansion prompts the need for the assessment of a variety of environmental and geographical constraints as well as technical and economic factors, which ensure socio-economically and ecologically sound biogas development. In this paper, both spatial and non-spatial data were integrated to the GIS model to help determine the optimal sites for installing anaerobic digesters (AD). The focus was placed on animal manure (from cattle and pig populations), and co-substrates such as crop silage. Furthermore, the paper provides insight into the structure of cost and benefits in order to examine what incentive measures suffice to force biogas development and how much biogas feedstock could cost to make investments viable. The techno-economic assessment was carried out for combined heat and power generation and bio-methane injection into the gas grid. The methodology was applied to Kujawsko-Pomorskie Voivodeship.     

Overview of hydrogen production technologies from biogas and the applications in fuel cells

Traditionally, H₂ is a large-scale production by the reforming process of light hydrocarbons, mainly natural gas, used by the chemical industry. However, the reforming technologies currently used encounter numerous technical/scientific challenges, which depend on the quality of raw materials, the conversion efficiency and security needs for the integration of H₂ production, purification and use, among others. Biogas is a high-potential versatile raw material for reforming processes, which can be used as an alternative CH₄ source. The production of H₂ from renewable sources, such as biogas, helps to largely reduce greenhouse gas emissions. Within this context, the integration of biogas reforming processes and the activation of fuel cell using H₂ represent an important route for generating clean energy, with added high-energy efficiency. This work expounds a literature review of the biogas reforming technologies, emphasizing the types of fuel cells available, the advantages offered by each route and the main problems faced.     

Potential and cost of electricity generation from human and animal waste in Spain

The energy contents of human and animal waste generated in Spain is estimated, as is the electricity that could be potentially generated from such waste. The waste considered is municipal solid waste, sewage sludge and livestock manure; several energy-recovery options are analyzed for the first one, viz the collection of landfill gas, incineration and anaerobic digestion. To estimate the potential, we use geo-referenced statistical human and animal population data disaggregated to the county level. This level of disaggregation allows the implementation of a cost model for the transformation of the waste into electricity, using a variety of technologies. The model considers the cost of transporting the waste to the transformation plant, and takes into account the economies of scale afforded by larger plants for the combined treatment of the waste in the county. The result is a generation-cost curve, which sorts by increasing costs the generation potential in the whole of the territory. The overall limits, in terms of primary energy and without considering alternative uses for the waste are between 725 and 4438 ktoe/y (depending on the energy-recovery method) for municipal solid waste; 142 ktoe/y for sewage sludge; and 1794 ktoe/y for livestock manure. The cost of the electricity generated depends greatly on the type of residue and the technology used for the transformation. Thus, the most economical option is the incineration of municipal solid waste, with an entry cost of around 4 c€/kWh. The generation entry-costs from livestock manure and sewage sludge are on the other hand in excess of 8 c€/kWh.     

Genetic diversity analysis by RAPD markers in candidate plus trees of Pongamia pinnata, a promising source of bioenergy

Pongamia pinnata has received much attention in recent years as a source of seed oil that can provide a substitute for diesel fuel. Very little molecular work has been reported on this species. This paper reports our studies on the diversity amongst the CPTs (candidate plus trees) of P. pinnata previously identified on the basis of morphometric traits, particularly pod and seed traits. For this RAPD (random amplified polymorphic DNA) markers were used to determine the genetic diversity among 10 genotypes of P. pinnata CPTs selected for suitability for energy production. For further investigation, 18 primers generating stable band patterns from 40 tested arbitrary primers were selected. A total of 210 amplification products were obtained of which 10.48% were polymorphic. The genetic similarity index ranged from 0.11 to 0.87. Genetic distance values were used to generate a dendrogram (UPGMA) between the genotypes. The Mantel method used for comparing the similarity matrixes produced correlation coefficients that were statistically significant for the RAPD marker. This genomic analysis allows a cost effective characterization of CPTs of P. pinnata. The present investigation supports in future the development of genetic map in Pongamia which are a highly useful tool in breeding and may provide information on the inheritance of features crucial for increase seed yield, oil content and the resistance to key insects and pests. Thus this study warrants Pongamia producers to realize its full potential and contributes for its sustainable production and improvement.     

Production of producer gas from sugarcane bagasse and carpentry waste and its sustainable use in a dual fuel CI engine: A performance,emission, and noise investigation

Due to ever increasing use of conventional fuels and improper utilization of renewables, air pollution and GHG (Green House Gas) emissions are the primary areas of concern. Due to this, the world is now shifting interest towards the synthesis and use of alternate fuels; that can replace the conventional fuels. Present work focuses on an experimental investigation, which is carried out on two different biomass materials – sugarcane bagasse and carpentry waste in 1:1 ratio. Biomass samples were used to synthesize producer gas in a downdraft gasifier with a gas flow rate of 5.07 Nm³/h. Producer gas was blended with diesel and fired in a dual fuel CI engine. Engine performance was smooth while it was tested for six load variations for noise characteristics and various performance and emission parameters. A maximum reduction in diesel consumption by 45.7% and NOx emissions by 69.5% was reported with a slight increase (～3.4 dB) in the noise.