Biogas production in regional integrated biodegradable waste treatment – Possibilities for improving energy performance and reducing GHG emissions

The greatest threat that the biodegradable waste causes on the environment is the methane produced in landfills by the decomposition of this waste. The Landfill Directive (1999/31/EC) aims to reduce the landfilling of biodegradable waste. In Finland, 31% of biodegradable municipal waste ended up into landfills in 2012. The pressure of reducing disposing into landfills is greatly increased by the forthcoming landfill ban on biodegradable waste in Finland. There is a need to discuss the need for increasing the utilization of biodegradable waste in regional renewable energy production to utilize the waste in a way that allows the best possibilities to reduce GHG emissions. The objectives of the thesis are: (1) to find important factors affecting renewable energy recovery possibilities from biodegradable waste, (2) to determine the main factors affecting the GHG balance of biogas production system and how to improve it and (3) to find ways to define energy performance of biogas production systems and what affects it. According to the thesis, the most important factors affecting the regional renewable energy possibilities from biodegradable waste are: the amount of available feedstock, properties of feedstock, selected utilization technologies, demand of energy and material products and the economic situation of utilizing the feedstocks. The biogas production by anaerobic digestion was seen as the main technology for utilizing biodegradable waste in agriculturally dense areas. The main reason for this is that manure was seen as the main feedstock, and it can be best utilized with anaerobic digestion, which can produce renewable energy while maintaining the spreading of nutrients on arable land. Biogas plants should be located close to the heat demand that would be enough to receive the produced heat also in the summer months and located close to the agricultural area where the digestate could be utilized. Another option for biogas use is to upgrade it to biomethane, which would require a location close to the natural gas grid. The most attractive masses for biogas production are municipal and industrial biodegradable waste because of gate fees the plant receives from them can provide over 80% of the income. On the other hand, directing gate fee masses for small-scale biogas plants could make dispersed biogas production more economical. In addition, the combustion of dry agricultural waste such as straw would provide a greater energy amount than utilizing them by anaerobic digestion. The complete energy performance assessment of biogas production system requires the use of more than one system boundary. These can then be used in calculating output–input ratios of biogas production, biogas plant, biogas utilization and biogas production system, which can be used to analyze different parts of the biogas production chain. At the moment, it is difficult to compare different biogas plants since there is a wide variation of definitions for energy performance of biogas production. A more consistent way of analyzing energy performance would allow comparing biogas plants with each other and other recovery systems and finding possible locations for further improvement. Both from the GHG emission balance and energy performance point of view, the energy consumption at the biogas plant was the most significant factor. Renewable energy use to fulfil the parasitic energy demand at the plant would be the most efficient way to reduce the GHG emissions at the plant. The GHG emission reductions could be increased by upgrading biogas to biomethane and displacing natural gas or petrol use in cars when compared to biogas CHP production. The emission reductions from displacing mineral fertilizers with digestate were seen less significant, and the greater N2O emissions from spreading digestate might surpass the emission reductions from displacing mineral fertilizers.

Potential to decrease GHG emissions from biomass resources in China

This paper describes the environment issues which are caused by fossil fuel utilization, and the available of biomass resources and relevant applications in China and relevant policy for supporting biomass resources development. In addition the sustainable technology for energy and fuels generation in China and the advantages and disadvantages of technologies are presented as well. This paper aims to find out how the policy can promotes the biomass resource development and from environment aspect to see why the biomass resources should replace fossil fuels in the future. In this paper the life cycle assessment of straw biomass resource will be as an example to present the same amount of energy produced by straw and coal, the different amount of emission will be emitted.

The effects of location, feedstock availability, and supply-chain logistics on the greenhouse gas emissions of forest-biomass energy utilization in Finland

Forest biomass represents a geographically distributed feedstock, and geographical location affects the greenhouse gas (GHG) performance of a given forest-bioenergy system in several ways. For example, biomass availability, forest operations, transportation possibilities and the distances involved, biomass end-use possibilities, fossil reference systems, and forest carbon balances all depend to some extent on location. The overall objective of this thesis was to assess the GHG emissions derived from supply and energy-utilization chains of forest biomass in Finland, with a specific focus on the effect of location in relation to forest biomass’s availability and the transportation possibilities. Biomass availability and transportation-network assessments were conducted through utilization of geographical information system methods, and the GHG emissions were assessed by means of lifecycle assessment. The thesis is based on four papers in which forest biomass supply on industrial scale was assessed. The feedstocks assessed in this thesis include harvesting residues, smalldiameter energy wood and stumps. The principal implication of the findings in this thesis is that in Finland, the location and availability of biomass in the proximity of a given energyutilization or energy-conversion plant is not a decisive factor in supply-chain GHG emissions or the possible GHG savings to be achieved with forest-biomass energy use. Therefore, for the greatest GHG reductions with limited forest-biomass resources, energy utilization of forest biomass in Finland should be directed to the locations where most GHG savings are achieved through replacement of fossil fuels. Furthermore, one should prioritize the types of forest biomass with the lowest direct supply-chain GHG emissions (e.g., from transport and comminution) and the lowest indirect ones (in particular, soil carbon-stock losses), regardless of location. In this respect, the best combination is to use harvesting residues in combined heat and power production, replacing peat or coal.

Greenhouse gas emissions from peat and biomass-derived fuels, electricity and heat — Estimation of various production chains by using LCA methodology

More discussion is required on how and which types of biomass should be used to achieve a significant reduction in the carbon load released into the atmosphere in the short term. The energy sector is one of the largest greenhouse gas (GHG) emitters and thus its role in climate change mitigation is important. Replacing fossil fuels with biomass has been a simple way to reduce carbon emissions because the carbon bonded to biomass is considered as carbon neutral. With this in mind, this thesis has the following objectives: (1) to study the significance of the different GHG emission sources related to energy production from peat and biomass, (2) to explore opportunities to develop more climate friendly biomass energy options and (3) to discuss the importance of biogenic emissions of biomass systems. The discussion on biogenic carbon and other GHG emissions comprises four case studies of which two consider peat utilization, one forest biomass and one cultivated biomasses. Various different biomass types (peat, pine logs and forest residues, palm oil, rapeseed oil and jatropha oil) are used as examples to demonstrate the importance of biogenic carbon to life cycle GHG emissions. The biogenic carbon emissions of biomass are defined as the difference in the carbon stock between the utilization and the non-utilization scenarios of biomass. Forestry-drained peatlands were studied by using the high emission values of the peatland types in question to discuss the emission reduction potential of the peatlands. The results are presented in terms of global warming potential (GWP) values. Based on the results, the climate impact of the peat production can be reduced by selecting high-emission-level peatlands for peat production. The comparison of the two different types of forest biomass in integrated ethanol production in pulp mill shows that the type of forest biomass impacts the biogenic carbon emissions of biofuel production. The assessment of cultivated biomasses demonstrates that several selections made in the production chain significantly affect the GHG emissions of biofuels. The emissions caused by biofuel can exceed the emissions from fossil-based fuels in the short term if biomass is in part consumed in the process itself and does not end up in the final product. Including biogenic carbon and other land use carbon emissions into the carbon footprint calculations of biofuel reveals the importance of the time frame and of the efficiency of biomass carbon content utilization. As regards the climate impact of biomass energy use, the net impact on carbon stocks (in organic matter of soils and biomass), compared to the impact of the replaced energy source, is the key issue. Promoting renewable biomass regardless of biogenic GHG emissions can increase GHG emissions in the short term and also possibly in the long term.

Climate change and global responsibility - the role of energy consumption, GDP and CO2 emissions

Climate change is one of the biggest challenges faced by this generation. Despite being the single most important environmental challenge facing the planet and despite over two decades of international climate negotiations, global greenhouse gas (GHG) emissions continue to rise. By the middle of this century, GHGs must be reduced by as much as 40-70% if dangerous climate change is to be avoided. In the Kyoto Protocol no quantitative emission limitation and reduction commitments were placed on the developing countries. For the planning of the future commitments period and possible participation of developing countries, information of the functioning of the energy systems, CO2 emissions development in different sectors, energy use and technological development in developing countries is essential. In addition to the per capita emissions, the efficiency of the energy system in relation to GHG emissions is crucial for the decision of future long-term burden sharing between countries. Country’s future development of CO2 emissions can be defined by the estimated CO2 intensity of the future and the estimated GDP growth. The changes in CO2 intensity depend on several factors, but generally developed countries’ intensity has been increasing in the industrialization phase and decreasing when their economy shifts more towards the system dominated by the service sector. The level of the CO2 intensity depends by a large extent on the production structure and the energy sources that are used. Currently one of the most urgent issues regarding global climate change is to decide the future of the Kyoto Protocol. Negotiations on this topic have already been initiated, with the aim of being finalised by the 2015. This thesis provides insights into the various approaches that can be used to characterise the concept of comparable efforts for developing countries in a future international climate agreement. The thesis examines the post-Kyoto burden sharing questions for developing countries using the contraction and convergence model, which is one approach that has been proposed to allocate commitments regarding future GHG emissions mitigation. This new approach is a practical tool for the evaluation of the Kyoto climate policy process and global climate change negotiations from the perspective of the developing countries.

Sustainability of palm oil production and opportunities for Finnish technology and know-how transfer

The global demand for palm oil is growing, thus prompting an increase in the global production particularly in Malaysia and Indonesia. Such increasing demand for palm oil is due to palm oil’s relatively cheap price and versatile advantage both in edible and non-edible applications. Along with the increasing demand for palm oil, particularly for the production of biofuel, is a heated debate on its sustainability. Ecological degradation, climate change and social issues are among the main sustainability issues pressing the whole palm oil industry today. Clean Development Mechanism (CDM) projects fulfilling the imperatives of the Kyoto Protocol are starting to gain momentum in Malaysia as reflected by the increasing registration of CDM projects in the palm oil mills. Most CDM projects in palm oil mills are on waste-to-energy, cocomposting, and methane recovery with the latter being the most common. The study on greenhouse gases (GHG) in the milling process points that biogas collection and energy utilisation has the greatest positive effect on GHG balance. On the other hand, empty fruit bunches (EFB) end-use as energy and high energy efficiency of the mill have the least effect on GHG balance of the mill. The range of direct GHG emissions from the palm oil mill is from 2.5 to 27 gCO2e/MJCPO, while the range of GHG emissions with all indirect and avoided emissions included is from -9 to 29 gCO2e/MJCPO. Comparing this GHG balance result with that of the EU RES-Directive suggests a further check on the values and emissions consideration of the latter.

The Environmental Status of the Port of HaminaKotka

This study is a part of the Ecologically Friendly Port Ust-Luga (EFP) project. The purpose of this study is to examine the environmental status of the Finnish ports and, more specifically, the Port of HaminaKotka. An analysis of the environmental status is performed mainly as a literature review, because the Finnish ports must comply with Finnish and EU legislation and with the binding international regulations and conventions created by different organizations. The International Maritime Organisation (IMO) has done groundbreaking work in the field of maritime safety and maritime environmental protection. The MARPOL convention has a great impact on decreasing pollution from international shipping and it applies to 99% of the world’s merchant tonnage. Pollution prevention covers: Oil pollution, Chemical pollution, Air pollution and GHG Emissions, Dumping of Wasted and Other Matters, Garbage, Sewage, Port Reception Facilities, Special Areas under MARPOL and Particularly Sensitive Sea Areas. There is also Pollution Prevention for other treaties like anti-fouling systems used on ships, the transfer of alien species by ships’ ballast water and the environmentally sound recycling of ships. There are more than twenty different EU and international regulations that influence ports and port operations in Finland. In addition, there is also national legislation that has an effect on Finnish ports. For the most part, the legislation for ports is common in the EU area, but the biggest and most important difference between the legislation in Finland and other EU countries is due to the Act on Environmental Impact Assessment Procedure. The Act states that the environmental impact assessment procedure shall be applied to projects that may have significant adverse environmental impacts, due to the special features of Finland`s nature and environment. In this Act, the term environmental impact refers to the direct and indirect effects inside and outside Finnish territory of a project or operations on human health, living conditions and amenity; soil, water, air, climate, organisms, interaction between them and biodiversity; community structure, buildings, landscape, townscape and cultural heritage; utilization of natural resources. In Finland, the Environmental Permit requires that ports collect all necessary information concerning environmental effects and make required reports to the Finnish authorities, stakeholders and the public. Commonly, environmental reporting is public and environmental achievements are emphasized in reporting and in media. At the moment, the problem in environmental reporting is that it’s difficult to compare data from different ports. There is enough data concerning the environmental effects and performance, but the manner of reporting and the quality of the data varies between ports. There are differences in the units and codes used, in some cases the information is not sufficient and it can even be rather unreliable. There are also differences regarding the subjects that are emphasized in reporting.

Comparative lifecycle assessment on organic and conventional carrots – case: Carrots from South-Savo and imported carrots from Italy

Organic farming is perceived to be an environmental friendly method of food production, thus assumed to be an alternative means of minimizing food-based environmental footprints. However, lower yield and unproductive years in organic crop rotation raise questions of whether it is really an environmentally friendly farming practice. Thus, the aim of this thesis was to examine the carbon footprint and energy demands of organic carrots cultivated and sold in South-Savo, Finland and compare them with those of local and imported conventional carrots using lifecycle assessment (LCA) as a method. From the investigation, it was found that organic carrots produced in South-Savo have the lowest GHG emissions and energy demand. The GHG emissions of local organic, local conventional and imported conventional carrots were found to be 4g CO2 eq. kgcarrots-1, 142g CO2 eq. kgcarrots-1 and 280 g CO2 eq. kgcarrots-1, respectively. On the other hand, energy demand for those carrots was found to be 1,33 MJ, 1,88 MJ and 3,68 MJ kgcarrots-1. Furthermore, it was also found that local organic carrots would have approximately similar GHG emissions as conventional counterpart if soil carbon stock change was excluded from the study.

Potential for Greenhouse Gas Emission Reductions by Using Biomethane as a Road Transportation Fuel

The aim of this thesis is to study whether the use of biomethane as a transportation fuel is reasonable from climate change perspective. In order to identify potentials and challenges for the reduction of greenhouse gas (GHG) emissions, this dissertation focuses on GHG emission comparisons, on feasibility studies and on the effects of various calculation methodologies. The GHG emissions calculations are carried out by using life cycle assessment (LCA) methodologies. The aim of these LCA studies is to figure out the key parameters affecting the GHG emission saving potential of biomethane production and use and to give recommendations related to methodological choices. The feasibility studies are also carried out from the life cycle perspective by dividing the biomethane production chain for various operators along the life cycle of biomethane in order to recognize economic bottlenecks. Biomethane use in the transportation sector leads to GHG emission reductions compared to fossil transportation fuels in most cases. In addition, electricity and heat production from landfill gas, biogas or biomethane leads to GHG reductions as well. Electricity production for electric vehicles is also a potential route to direct biogas or biomethane energy to transportation sector. However, various factors along the life cycle of biomethane affect the GHG reduction potentials. Furthermore, the methodological selections have significant effects on the results. From economic perspective, there are factors related to different operators along the life cycle of biomethane, which are not encouraging biomethane use in the transportation sector. To minimize the greenhouse gas emissions from the life cycle of biomethane, waste feedstock should be preferred. In addition, energy consumption, methane leakages, digestate utilization and the current use of feedstock or biogas are also key factors. To increase the use of biomethane in the transportation sector, political steering is needed to improve the feasibility for the operators. From methodological perspective, it is important to recognize the aim of the life cycle assessment study. The life cycle assessment studies can be divided into two categories: 1.) To produce average GHG information of biomethane to evaluate the acceptability of biomethane use compared to fossil transportation fuels. 2.) To produce GHG information of biomethane related to actual decision-making situations. This helps to figure out the actual GHG emission changes in cases when feedstock, biogas or biomethane are already in other use. For example directing biogas from electricity production to transportation use does not necessarily lead to additional GHG emission reductions. The use of biomethane seems to have a lot of potential for the reduction of greenhouse gas emissions as a transportation fuel. However, there are various aspects related to production processes, to the current use of feedstock or biogas and to the feasibility that have to be taken into account.

The Possibility of Greenhouse Gas Mitigation in Ethiopian Cement Industry

Cement industry significantly associated with high greenhouse gas (GHG) emissions. Considering the environmental impact, particularly global warming potential, it is important to reduce these emissions to air. The aim of the study is to investigate the mitigation possibility of GHG emissions in Ethiopian cement industry. Life cycle assessment (LCA) method used to identify and quantify GHG emissions during one ton of ordinary portland cement (OPC) production. Three mitigation scenarios: alternative fuel use, clinker substitution and thermal energy efficiency were applied on a representative gate-to-gate flow model developed with GaBi 6 software. The results of the study indicate that clinker substitution and alternative fuel use play a great role for GHG emissions mitigation with affordable cost. Applying most energy efficient kiln technology, which in turn reduces the amount of thermal energy use, has the least GHG emissions reduction intensity and high implementation cost comparing to the other scenarios. It was found that the cumulative GHG emissions mitigation potential along with other selected mitigation scenarios can be at least 48.9% per ton of cement production.

Production of magnesium carbonates from serpentinites for CO2 mineral sequestration : optimisation towards industrial application

Global warming is one of the most alarming problems of this century. Initial scepticism concerning its validity is currently dwarfed by the intensification of extreme weather events whilst the gradual arising level of anthropogenic CO2 is pointed out as its main driver. Most of the greenhouse gas (GHG) emissions come from large point sources (heat and power production and industrial processes) and the continued use of fossil fuels requires quick and effective measures to meet the world’s energy demand whilst (at least) stabilizing CO2 atmospheric levels. The framework known as Carbon Capture and Storage (CCS) – or Carbon Capture Utilization and Storage (CCUS) – comprises a portfolio of technologies applicable to large‐scale GHG sources for preventing CO2 from entering the atmosphere. Amongst them, CO2 capture and mineralisation (CCM) presents the highest potential for CO2 sequestration as the predicted carbon storage capacity (as mineral carbonates) far exceeds the estimated levels of the worldwide identified fossil fuel reserves. The work presented in this thesis aims at taking a step forward to the deployment of an energy/cost effective process for simultaneous capture and storage of CO2 in the form of thermodynamically stable and environmentally friendly solid carbonates. R&D work on the process considered here began in 2007 at Åbo Akademi University in Finland. It involves the processing of magnesium silicate minerals with recyclable ammonium salts for extraction of magnesium at ambient pressure and 400‐440⁰C, followed by aqueous precipitation of magnesium in the form of hydroxide, Mg(OH)2, and finally Mg(OH)2 carbonation in a pressurised fluidized bed reactor at ~510⁰C and ~20 bar PCO2 to produce high purity MgCO3. Rock material taken from the Hitura nickel mine, Finland, and serpentinite collected from Bragança, Portugal, were tested for magnesium extraction with both ammonium sulphate and bisulphate (AS and ABS) for determination of optimal operation parameters, primarily: reaction time, reactor type and presence of moisture. Typical efficiencies range from 50 to 80% of magnesium extraction at 350‐450⁰C. In general ABS performs better than AS showing comparable efficiencies at lower temperature and reaction times. The best experimental results so far obtained include 80% magnesium extraction with ABS at 450⁰C in a laboratory scale rotary kiln and 70% Mg(OH)2 carbonation in the PFB at 500⁰C, 20 bar CO2 pressure for 15 minutes. The extraction reaction with ammonium salts is not at all selective towards magnesium. Other elements like iron, nickel, chromium, copper, etc., are also co‐extracted. Their separation, recovery and valorisation are addressed as well and found to be of great importance. The assessment of the exergetic performance of the process was carried out using Aspen Plus® software and pinch analysis technology. The choice of fluxing agent and its recovery method have a decisive sway in the performance of the process: AS is recovered by crystallisation and in general the whole process requires more exergy (2.48–5.09 GJ/tCO2sequestered) than ABS (2.48–4.47 GJ/tCO2sequestered) when ABS is recovered by thermal decomposition. However, the corrosive nature of molten ABS and operational problems inherent to thermal regeneration of ABS prohibit this route. Regeneration of ABS through addition of H2SO4 to AS (followed by crystallisation) results in an overall negative exergy balance (mainly at the expense of low grade heat) but will flood the system with sulphates. Although the ÅA route is still energy intensive, its performance is comparable to conventional CO2 capture methods using alkanolamine solvents. An energy‐neutral process is dependent on the availability and quality of nearby waste heat and economic viability might be achieved with: magnesium extraction and carbonation levels ≥ 90%, the processing of CO2‐containing flue gases (eliminating the expensive capture step) and production of marketable products.

Characterization and Investigation on Material Compatibilities of Building Integrated Photovoltaic Module Components

Building Integrated Photovoltaics (BIPV) are considered as the future of photovoltaic (PV) technology. The advantage of BIPV system is its multi-functionality; they fulfil the functions of a building envelope with the added benefit of generating power by replacing the traditional roofing and façade materials with PV that generate power. In this thesis, different types of PV cells and modules have been described in detail with their efficiencies and usage trends in the last decade. The different BIPV products for roof and façade are discussed in detail giving several examples. The electricity generation potential of BIPV in selected countries is compared with their actual electricity consumption. Further, the avoided greenhouse gas (GHG) emissions associated with electricity generation from traditional sources and transportation and distribution (T&D) losses are calculated. The results illustrate huge savings in GHGs. In BIPV different types of façade and backsheets are used. In this thesis, selected backsheets and façade were characterized in terms of their surface structure identification using infrared spectroscopy (FTIR-ATR), scanning electron microscopy with energy dispersive X-ray (SEM-EDX) and physical characterization using surface energy measurements. By using FTIR-ATR, surface polymeric materials were identified and with SEM-EDX, identification of the surface elements was possible. Surface energy measurements were useful in finding the adhesives and knowing the surface energies of the various backsheets and façade. The strength of adhesion between the facade and backsheets was studied using peel test. Four different types of adhesives were used to study the fracture pattern and peel tests values to identify the most suitable adhesive. It was found out that pretreatment increased the adhesive strength significantly.

The role of nuclear and other conventional power plants in the flexible energy system

This thesis reviews the role of nuclear and conventional power plants in the future energy system. The review is done by utilizing freely accesible publications in addition to generating load duration and ramping curves for Nordic energy system. As the aim of the future energy system is to reduce GHG-emissions and avoid further global warming, the need for flexible power generation increases with the increased share of intermittent renewables. The goal of this thesis is to offer extensive understanding of possibilities and restrictions that nuclear power and conventional power plants have regarding flexible and sustainable generation. As a conclusion, nuclear power is the only technology that is able to provide large scale GHG-free power output variations with good ramping values. Most of the currently operating plants are able to take part in load following as the requirement to do so is already required to be included in the plant design. Load duration and ramping curves produced prove that nuclear power is able to cover most of the annual generation variation and ramping needs in the Nordic energy system. From the conventional power generation methods, only biomass combustion can be considered GHG-free because biomass is considered carbon neutral. CFB combusted biomass has good load follow capabilities in good ramping and turndown ratios. All the other conventional power generation technologies generate GHG-emissions and therefore the use of these technologies should be reduced.

Mitigation possibilities to Greenhouse gas emissions from power production in India

Global warming is assertively the greatest environmental challenge for humans of 21st century. It is primarily caused by the anthropogenic greenhouse gas (GHG) that trap heat in the atmosphere. Because of which, the GHG emission mitigation, globally, is a critical issue in the political agenda of all high-profile nations. India, like other developing countries, is facing this threat of climate change while dealing with the challenge of sustaining its rapid economic growth. India’s economy is closely connected to its natural resource base and climate sensitive sectors like water, agriculture and forestry. Due to Climate change the quality and distribution of India’s natural resources may transform and lead to adverse effects on livelihood of its people. Therefore, India is expected to face a major threat due to the projected climate change. This study proposes possible solutions for GHG emission mitigation that are specific to the power sector of India. The methods discussed here will take Indian power sector from present coal dominant ideology to a system, centered with renewable energy sources. The study further proposes a future scenario for 2050, based on the present Indian government policies and global energy technologies advancements.

CH‚́ emissions from a West Siberian mire

Tiivistelmä: Metaanivuo länsi-siperialaiselta suolta