Anaerobic Digestate Treatment Selection Model for Biogas Plant Costs and Emissions Reduction

Agriculture is one of the leading sectors on the global level contributing to greenhouse gas (GHG) emissions increase. With the utilization of biogas production technology within the agriculture sector, ecological benefits could be achieved, with immediate economic profit. Therefore, to retain economic profit and environmental sustainability, implementation of bioeconomy principles is of key importance. This paper examines four options of digestate treatment, which is identified as one of the highest operational cost for the biogas plant. A simple and robust model in Excel Solver was developed to determine the best solution for minimising GHG emissions and maximise profit for the biogas plant operator, through an upgrade of the plant with digestate treatment technologies. The model was implemented on a case of a Croatian biogas plant and the best solution in terms of GHG reduction and profit increase proved to be fertilizer production (Option 1), through a crystallization process of struvite within the digestate. This option obtains a significant reduction in GHG emissions compared to standard biogas production without additional upgrades (Option 4), by over 90%, and increase of profit for the biogas plant operator, which diversifies the income source and creates multiple positive impacts on the environment.

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International overview on waste to biofuel options with a focsu on waste potentials in Germany and funding incentives in the EC

Global NEST Journal ◽

10.30955/gnj.000850 ◽

2013 ◽

Vol 14 (2) ◽

pp. 183-191

Keyword(s):

Anaerobic Fermentation ◽

Biogas Production ◽

Raw Materials ◽

Ghg Emissions ◽

Small Scale ◽

Double Counting ◽

Industrialized Countries ◽

Fischer Tropsch ◽

The Past ◽

Ghg Reduction

Biofuels represent a possibility to reduce greenhouse gas (GHG) emissions within the transport sector. In this context the sustainability of biofuels, especially so called 1st generation biofuels led to controversial discussions in the past. Biofuels from waste and residues represent a well suited but quantitative limited alternative due to their sustainability. At an international level, different approaches for converting waste and residues into biofuels can be found. Developing countries in general use classic transesterification of waste fats to produce biodiesel. Technically advanced options such as pyrolysis, gasification, Fischer-Tropsch-Diesel, anaerobic fermentation and distillation, as well as biogas production coupled with biomethane upgrading, are mostly found in industrialized countries. Within this study, different waste to biofuel options are reviewed ranging from small scale to industrial scale and take into account used raw materials, technological application and (potential) GHG-reduction. Further the potential of several wastes and residues for gasification processes and synthesis of biofuels in Germany is described. Biofuel from waste offers promising funding incentives because of the “double counting” according to 2009/28/EC and the switch in mandatory blending from an amount based quota to a GHG-based blending quota in 2015.

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Improving the Sustainability of Dairy Slurry by A Commercial Additive Treatment

Sustainability ◽

10.3390/su11184998 ◽

2019 ◽

Vol 11 (18) ◽

pp. 4998 ◽

Cited By ~ 4

Author(s):

Federica Borgonovo ◽

Cecilia Conti ◽

Daniela Lovarelli ◽

Valentina Ferrante ◽

Marcella Guarino

Keyword(s):

Climate Change ◽

Environmental Impact ◽

Environmental Sustainability ◽

Ghg Emissions ◽

Mineral Fertilizer ◽

Cattle Slurry ◽

N Loss ◽

Beneficial Effects ◽

Environmental Impact Categories ◽

Carbon Dioxide Co2

Ammonia (NH3), methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2) emissions from livestock farms contribute to negative environmental impacts such as acidification and climate change. A significant part of these emissions is produced from the decomposition of slurry in livestock facilities, during storage and treatment phases. This research aimed at evaluating the effectiveness of the additive “SOP LAGOON” (made of agricultural gypsum processed with proprietary technology) on (i) NH3 and Greenhouse Gas (GHG) emissions, (ii) slurry properties and N loss. Moreover, the Life Cycle Assessment (LCA) method was applied to assess the potential environmental impact associated with stored slurry treated with the additive. Six barrels were filled with 65 L of cattle slurry, of which three were used as a control while the additive was used in the other three. The results indicated that the use of the additive led to a reduction of total nitrogen, nitrates, and GHG emissions. LCA confirmed the higher environmental sustainability of the scenario with the additive for some environmental impact categories among which climate change. In conclusion, the additive has beneficial effects on both emissions and the environment, and the nitrogen present in the treated slurry could partially displace a mineral fertilizer, which can be considered an environmental credit.

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Biogas Production Using Anaerobic Digestion of Industrial Waste

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.832.55 ◽

2016 ◽

Vol 832 ◽

pp. 55-62

Author(s):

Ján Gaduš ◽

Tomáš Giertl ◽

Viera Kažimírová

Keyword(s):

Anaerobic Digestion ◽

Industrial Waste ◽

Large Scale ◽

Biogas Production ◽

Biogas Plant ◽

Parallel Operation ◽

Paper Production ◽

Biochemical Conversion ◽

Mixed Biomass ◽

Economic Balance

In the paper experiments and theory of biogas production using industrial waste from paper production as a co-substrate are described. The main aim of the experiments was to evaluate the sensitivity and applicability of the biochemical conversion using the anaerobic digestion of the mixed biomass in the pilot fermentor (5 m3), where the mesophillic temperature was maintained. It was in parallel operation with a large scale fermentor (100 m3). The research was carried out at the biogas plant in Kolíňany, which is a demonstration facility of the Slovak University of Agriculture in Nitra. The experiments proved that the waste arising from the paper production can be used in case of its appropriate dosing as an input substrate for biogas production, and thus it can improve the economic balance of the biogas plant.

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Innovations in anaerobic digestion: a model-based study

Biotechnology for Biofuels ◽

10.1186/s13068-020-01864-z ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Karol Postawa ◽

Jerzy Szczygieł ◽

Marek Kułażyński

Keyword(s):

Mathematical Model ◽

Anaerobic Digestion ◽

Production Efficiency ◽

Biogas Production ◽

Biogas Plant ◽

Methane Content ◽

Pig Manure ◽

Pig Slurry ◽

Production Chain ◽

The Impact

Abstract Background Increasing the efficiency of the biogas production process is possible by modifying the technological installations of the biogas plant. In this study, specific solutions based on a mathematical model that lead to favorable results were proposed. Three configurations were considered: classical anaerobic digestion (AD) and its two modifications, two-phase AD (TPAD) and autogenerative high-pressure digestion (AHPD). The model has been validated based on measurements from a biogas plant located in Poland. Afterward, the TPAD and AHPD concepts were numerically tested for the same volume and feeding conditions. Results The TPAD system increased the overall biogas production from 9.06 to 9.59%, depending on the feedstock composition, while the content of methane was slightly lower in the whole production chain. On the other hand, the AHPD provided the best purity of the produced fuel, in which a methane content value of 82.13% was reached. At the same time, the overpressure leads to a decrease of around 7.5% in the volumetric production efficiency. The study indicated that the dilution of maize silage with pig manure, instead of water, can have significant benefits in the selected configurations. The content of pig slurry strengthens the impact of the selected process modifications—in the first case, by increasing the production efficiency, and in the second, by improving the methane content in the biogas. Conclusions The proposed mathematical model of the AD process proved to be a valuable tool for the description and design of biogas plant. The analysis shows that the overall impact of the presented process modifications is mutually opposite. The feedstock composition has a moderate and unsteady impact on the production profile, in the tested modifications. The dilution with pig manure, instead of water, leads to a slightly better efficiency in the classical configuration. For the TPAD process, the trend is very similar, but the AHPD biogas plant indicates a reverse tendency. Overall, the recommendation from this article is to use the AHPD concept if the composition of the biogas is the most important. In the case in which the performance is the most important factor, it is favorable to use the TPAD configuration.

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The role of the European small ruminant dairy sector in stabilising global temperatures: lessons from GWP* warming-equivalent emission metrics

Journal of Dairy Research ◽

10.1017/s0022029921000157 ◽

2021 ◽

pp. 1-8

Author(s):

Agustin del Prado ◽

Pablo Manzano ◽

Guillermo Pardo

Keyword(s):

Small Ruminant ◽

Ghg Emissions ◽

Small Ruminants ◽

Feed Additives ◽

Dairy Goat ◽

Emission Rates ◽

Animal Products ◽

Ghg Reduction ◽

Mitigate Climate Change ◽

Climate Neutrality

Abstract Recent calls advocate that a huge reduction in the consumption of animal products (including dairy) is essential to mitigate climate change and stabilise global warming below the 1.5 and 2°C targets. The Paris Agreement states that to stabilise temperatures we must reach a balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases (GHG) in the second half of this century. Consequently, many countries have adopted overall GHG reduction targets (e.g. EU, at least 40% by 2030 compared to 1990). However, using conventional metric-equivalent emissions (CO2-e GWP100) as the basis to account for emissions does not result in capturing the effect on atmospheric warming of changing emission rates from short-lived GHG (e.g. methane: CH4), which are the main source of GHG emissions by small ruminants. This shortcoming could be solved by using warming-equivalent emissions (CO2-we, GWP*), which can accurately link annual GHG emission rates to its warming effect in the atmosphere. In our study, using this GWP* methodology and different modelling approaches, we first examined the historical (1990–2018) contribution of European dairy small ruminant systems to additional atmosphere warming levels and then studied different emission target scenarios for 2100. These scenarios allow us to envision the necessary reduction of GHG emissions from Europe's dairy small ruminants to achieve a stable impact on global temperatures, i.e. to be climatically neutral. Our analysis showed that, using this type of approach, the whole European sheep and goat dairy sector seems not to have contributed to additional warming in the period 1990–2018. Considering each subsector separately, increases in dairy goat production has led to some level of additional warming into the atmosphere, but these have been compensated by larger emission reductions in the dairy sheep sector. The estimations of warming for future scenarios suggest that to achieve climate neutrality, understood as not adding additional warming to the atmosphere, modest GHG reductions of sheep and goat GHG would be required (e.g. via feed additives). This reduction would be even lower if potential soil organic carbon (SOC) from associated pastures is considered.

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Empirical Validation of a Biogas Plant Simulation Model and Analysis of Biogas Upgrading Potentials

Energies ◽

10.3390/en14092424 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2424

Author(s):

Jan Martin Zepter ◽

Jan Engelhardt ◽

Tatiana Gabderakhmanova ◽

Mattia Marinelli

Keyword(s):

Simulation Model ◽

Biogas Production ◽

Biogas Plant ◽

Raw Material ◽

Biogas Upgrading ◽

Integrated Energy Systems ◽

First Order Kinetics ◽

Biogas Plants ◽

Plant Simulation ◽

Kinetics Of

Biogas plants may support the transformation towards renewable-based and integrated energy systems by providing dispatchable co-generation as well as opportunities for biogas upgrading or power-to-X conversion. In this paper, a simulation model that comprises the main dynamics of the internal processes of a biogas plant is developed. Based on first-order kinetics of the anaerobic digestion process, the biogas production of an input feeding schedule of raw material can be estimated. The output of the plant in terms of electrical and thermal energy is validated against empirical data from a 3-MW biogas plant on the Danish island of Bornholm. The results show that the model provides an accurate representation of the processes within a biogas plant. The paper further provides insights on the functioning of the biogas plant on Bornholm as well as discusses upgrading potentials of biogas to biomethane at the plant from an energy perspective.

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An Investigation of the Potential Adoption of Anaerobic Digestion for Energy Production in Irish Farms

Environments ◽

10.3390/environments8020008 ◽

2021 ◽

Vol 8 (2) ◽

pp. 8

Author(s):

Sean O’Connor ◽

Ehiaze Ehimen ◽

Suresh C. Pillai ◽

Niamh Power ◽

Gary A. Lyons ◽

...

Keyword(s):

Anaerobic Digestion ◽

Energy Production ◽

Effective Means ◽

Ghg Emissions ◽

Co2 Reduction ◽

Agriculture Sector ◽

Lack Of Information ◽

High Investment ◽

On Farm ◽

Technology Ranking

Anaerobic digestion (AD) has been recognised as an effective means of simultaneously producing energy while reducing greenhouse gas (GHG) emissions. Despite having a large agriculture sector, Ireland has experienced little uptake of the technology, ranking 20th within the EU-28. It is, therefore, necessary to understand the general opinions, willingness to adopt, and perceived obstacles of potential adopters of the technology. As likely primary users of this technology, a survey of Irish cattle farmers was conducted to assess the potential of on-farm AD for energy production in Ireland. The study seeks to understand farmers’ motivations, perceived barriers, and preferred business model. The study found that approximately 41% of the 91 respondents were interested in installing AD on their farming enterprise within the next five years. These Likely Adopters tended to have a higher level of education attainment, and together, currently hold 4379 cattle, potentially providing 37,122 t year−1 of wastes as feedstock, resulting in a potential CO2 reduction of 800.65 t CO2-eq. year−1. Moreover, the results indicated that the primary consideration preventing the implementation of AD is a lack of information regarding the technology and high investment costs. Of the Likely Adopters and Possible Adopters, a self-owned and operated plant was the preferred ownership structure, while 58% expressed an interest in joining a co-operative scheme. The findings generated provide valuable insights into the willingness of farmers to implement AD and guidance for its potential widespread adoption.

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The potential of bio-methane as bio-fuel/bio-energy for reducing greenhouse gas emissions: a qualitative assessment for Europe in a life cycle perspective

Water Science & Technology ◽

10.2166/wst.2008.039 ◽

2008 ◽

Vol 57 (11) ◽

pp. 1683-1692 ◽

Cited By ~ 53

Author(s):

Andrea Tilche ◽

Michele Galatola

Keyword(s):

Wastewater Treatment ◽

Life Cycle ◽

Anaerobic Digestion ◽

Greenhouse Gas ◽

Industrial Wastewater ◽

Ghg Emissions ◽

Energy Crops ◽

Qualitative Assessment ◽

Potential Contribution ◽

Ghg Reduction

Anaerobic digestion is a well known process that (while still capable of showing new features) has experienced several waves of technological development. It was “born” as a wastewater treatment system, in the 1970s showed promise as an alternative energy source (in particular from animal waste), in the 1980s and later it became a standard for treating organic-matter-rich industrial wastewater, and more recently returned to the market for its energy recovery potential, making use of different biomasses, including energy crops. With the growing concern around global warming, this paper looks at the potential of anaerobic digestion in terms of reduction of greenhouse gas (GHG) emissions. The potential contribution of anaerobic digestion to GHG reduction has been computed for the 27 EU countries on the basis of their 2005 Kyoto declarations and using life cycle data. The theoretical potential contribution of anaerobic digestion to Kyoto and EU post-Kyoto targets has been calculated. Two different possible biogas applications have been considered: electricity production from manure waste, and upgraded methane production for light goods vehicles (from landfill biogas and municipal and industrial wastewater treatment sludges). The useful heat that can be produced as by-product from biogas conversion into electricity has not been taken into consideration, as its real exploitation depends on local conditions. Moreover the amount of biogas already produced via dedicated anaerobic digestion processes has also not been included in the calculations. Therefore the overall gains achievable would be even higher than those reported here. This exercise shows that biogas may considerably contribute to GHG emission reductions in particular if used as a biofuel. Results also show that its use as a biofuel may allow for true negative GHG emissions, showing a net advantage with respect to other biofuels. Considering also energy crops that will become available in the next few years as a result of Common Agricultural Policy (CAP) reform, this study shows that biogas has the potential of covering almost 50% of the 2020 biofuel target of 10% of all automotive transport fuels, without implying a change in land use. Moreover, considering the achievable GHG reductions, a very large carbon emission trading “value” could support the investment needs. However, those results were obtained through a “qualitative” assessment. In order to produce robust data for decision makers, a quantitative sustainability assessment should be carried out, integrating different methodologies within a life cycle framework. The identification of the most appropriate policy for promoting the best set of options is then discussed.

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Recycling Biogas Digestate from Energy Crops: Effects on Soil Properties and Crop Productivity

Applied Sciences ◽

10.3390/app11020750 ◽

2021 ◽

Vol 11 (2) ◽

pp. 750

Author(s):

Roberta Pastorelli ◽

Giuseppe Valboa ◽

Alessandra Lagomarsino ◽

Arturo Fabiani ◽

Stefania Simoncini ◽

...

Keyword(s):

Crop Yield ◽

Environmental Sustainability ◽

Biogas Production ◽

Aggregate Stability ◽

Soil Bulk Density ◽

Crop Productivity ◽

Energy Crop ◽

Mineral Fertilizers ◽

Total N ◽

Organic C

Digestate from biogas production can be recycled to the soil as conditioner/fertilizer improving the environmental sustainability of the energy supply chain. In a three-year maize-triticale rotation, we investigated the short-term effects of digestate on soil physical, chemical, and microbiological properties and evaluated its effectiveness in complementing the mineral fertilizers. Digestate soil treatments consisted of combined applications of the whole digestate and its mechanically separated solid fraction. Digestate increased soil total organic C, total N and K contents. Soil bulk density was not affected by treatments, while aggregate stability showed a transient improvement due to digestate treatments. A decrement of the transmission pores proportion and an increment of fissures was observed in digestate treated soils. Soil microbial community was only transiently affected by digestate treatments and no soil contamination from Clostridiaceae-related bacteria were observed. Digestate can significantly impair seed germination when applied at low dilution ratios. Crop yield under digestate treatment was similar to ordinary mineral-based fertilization. Overall, our experiment proved that the agronomic recycling of digestate from biogas production maintained a fair crop yield and soil quality. Digestate was confirmed as a valid resource for sustainable management of soil fertility under energy-crop farming, by combining a good attitude as a fertilizer with the ability to compensate for soil organic C loss.

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Evaluation of Eco-Efficiency of Two Alternative Agricultural Biogas Plants

Applied Sciences ◽

10.3390/app8112083 ◽

2018 ◽

Vol 8 (11) ◽

pp. 2083 ◽

Cited By ~ 15

Author(s):

Magdalena Muradin ◽

Katarzyna Joachimiak-Lechman ◽

Zenon Foltynowicz

Keyword(s):

Waste Heat ◽

Negative Impact ◽

Biogas Production ◽

Biogas Plant ◽

Waste To Energy ◽

Cost Calculation ◽

Processing Plant ◽

The European Union ◽

Levelized Cost Of Electricity ◽

Biogas Plants

Implementation of the circular economy is one of the priorities of the European Union, and energy efficiency is one of its pillars. This article discusses an effective use of agri-food industry waste for the purposes of waste-to-energy in biogas plants. Its basic objective is the comparative assessment of the eco-efficiency of biogas production depending on the type of feedstock used, its transport and possibility to use generated heat. The environmental impact of the analysed installations was assessed with the application of the Life Cycle Assessment (LCA) methodology. Cost calculation was performed using the Levelized Cost of Electricity (LCOE) method. The LCA analysis indicated that a biogas plant with a lower level of waste heat use where substrates were delivered by wheeled transport has a negative impact on the environment. The structure of distributed energy production cost indicates a substantial share of feedstock supply costs in the total value of the LCOE ratio. Thus, the factor affecting the achievement of high eco-efficiency is the location of a biogas plant in the vicinity of an agri-food processing plant, from which the basic feedstock for biogas production is supplied with the transmission pipeline, whereas heat is transferred for the needs of production processes in a processing plant or farm.

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