scholarly journals The Bioconversion of Sewage Sludge to Bio-Fuel: The Environmental and Economic Benefits

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2417 ◽  
Author(s):  
Adam Smoliński ◽  
Janusz Karwot ◽  
Jan Bondaruk ◽  
Andrzej Bąk
Keyword(s):  
Sewage Sludge ◽  
Fossil Fuels ◽  
Waste Water Treatment ◽  
Calorific Value ◽  
Dry Mass ◽  
Economic Benefits ◽  
Economic Feasibility ◽  
Hard Coal ◽  
Energy Potential ◽  
Industrial Energy

This paper aims to analyze the economic feasibility of generating a novel, innovative biofuel—bioenergy—obtained from deposit bio-components by means of a pilot installation of sewage sludge bio-conversion. Fuel produced from sewage sludge biomass bears the potential of being considered a renewable energy source. In the present study, 23 bioconversion cycles were conducted taking into consideration the different contents, types of high carbohydrate additives, moisture content of the mixture as well as the shape of the bed elements. The biofuel was produced using post fermentation sewage sludge for industrial energy and heat generation. Based on the presented research it was concluded that the composite biofuel can be co-combusted with hard coal with the optimal percentage share within the range of 20–30% w/w. Sewage sludge stabilized by means of anaerobic digestion carried out in closed fermentation chambers is the final product. The average values of the CO2, CO, NO, NOx and SO2 concentrations in flue gas from co-combustion of a bioconversion product (20% w/w) and coal were 5.43%, 1903 ppm, 300 ppm, 303 ppm and 179 ppm, respectively. In total, within a period of 4.5 years of the plant operation, 1853 Mg of fuel was produced and successfully co-combusted with coal in a power plant. The research demonstrated that in the waste water treatment sector there exists energy potential in terms of calorific value which translates into tangible benefits both in the context of energy generation as well as environmental protection. Over 700,000 Mg of bio-sewage sludge is generated annually in Poland. According to findings of the study presented in the paper, the proposed solution could give 970,000 Mg of dry mass of biomass qualified as energy biomass replacing fossil fuels.

scholarly journals Valorization of Sewage Sludge via Gasification and Transportation of Compressed Syngas

Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 556 ◽  
Author(s):  
Marek Mysior ◽  
Maciej Tomaszewski ◽  
Paweł Stępień ◽  
Jacek A. Koziel ◽  
Andrzej Białowiec
Keyword(s):  
Sewage Sludge ◽  
Energy Demand ◽  
Energy Transport ◽  
Compressibility Factor ◽  
Calorific Value ◽  
End Users ◽  
Economic Feasibility ◽  
Molar Ratio ◽  
Energy Potential ◽  
Molar Ratios

A significant challenge in the utilization of alternative gaseous fuels is to use their energy potential at the desired location, considering economic feasibility and sustainability. A potential solution is a compression, transportation in pressure tanks, and generation of electricity and heat directly at the recipient. In this research, the potential for generating syngas from abundant waste substrates was analyzed. The sewage sludge (SS) was used as an example of a bulky and abundant resource that could be valorized via gasification, compression, and transport to end-users in containers. A model was developed, and theoretical analyses were completed to examine the influence of the calorific value of the syngas produced from the SS gasification (under different temperatures and gasifying agents) on the efficiency of energy transportation of compressed syngas. First, the gasification simulation was carried out, assuming equilibrium in a downdraft gasifier (reactor) from 973–1473 K and five gasifying agents (O2, H2, CO2, water vapor, and air). Molar ratios of the gasifying agents to the (SS) C ranged from 0.1–1.0. The model predicted syngas composition, lower calorific values (LHV) for a given molar ratio of the gasification agent, and compressibility factor. It was shown that the highest LHV was obtained at 0.1 molar ratio for all gasifier agents. The highest LHV (~20 MJ∙(Nm3)−1) was obtained by gasification with H2 and the lowest (~13 MJ∙(Nm3)−1) in the case of air. Next, the available syngas volume in a compressed gas transportation unit and the stored energy was estimated. The largest syngas volume can be transported when O2 is used as a gasifying agent, but the highest amount of transported energy was estimated for gasification with H2. Finally, the techno-economic analyses showed that syngas from SS could be competitive when the energy of compressed syngas is compared with the demand of an average residential dwelling. The developed syngas energy transport system (SETS) concept proposes a new method to distribute compressed syngas in pressure tanks to end-users using all modes of transport carrying intermodal ISO containers. Future work should include the determination of energy demand for syngas compression, including pressure losses, heat losses, and analysis of the influence of syngas on storage and compression devices.

scholarly journals Energy Recovery from Sewage Sludge: The Case Study of Croatia

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1927 ◽  
Author(s):  
Dinko Đurđević ◽  
Paolo Blecich ◽  
Željko Jurić
Keyword(s):  
Sewage Sludge ◽  
Energy Recovery ◽  
Fossil Fuels ◽  
Wastewater Treatment Plants ◽  
Energy Generation ◽  
Fuel Oil ◽  
Hard Coal ◽  
Solar Drying ◽  
Sludge Disposal ◽  
Sludge Drying

Croatia produced 21,366 tonnes of dry matter (DM) sewage sludge (SS) in 2016, a quantity expected to surpass 100,000 tonnes DM by 2024. Annual production rates for future wastewater treatment plants (WWTP) in Croatia are estimated at 5.8–7.3 Nm3/people equivalent (PE) for biogas and 20–25 kgDM/PE of sewage sludge. Biogas can be converted into 12–16 kWhel/PE of electricity and 19–24 kWhth/PE of heat, which is sufficient for 30–40% of electrical and 80–100% of thermal autonomy. The WWTP autonomy can be increased using energy recovery from sewage sludge incineration by 60% for electricity and 100% of thermal energy (10–13 kWhel/PE and 30–38 kWhth/PE). However, energy for sewage sludge drying exceeds energy recovery, unless solar drying is performed. The annual solar drying potential is estimated between 450–750 kgDM/m2 of solar drying surface. The lower heating value of dried sewage sludge is 2–3 kWh/kgDM and this energy can be used for assisting sludge drying or for energy generation and supply to WWTPs. Sewage sludge can be considered a renewable energy source and its incineration generates substantially lower greenhouse gases emissions than energy generation from fossil fuels. For the same amount of energy, sewage sludge emits 58% fewer emissions than natural gas and 80% less than hard coal and fuel oil. Moreover, this paper analysed the feasibility of sludge disposal practices by analysing three scenarios (landfilling, co-incineration, and mono-incineration). The analysis revealed that the most cost-effective sewage sludge disposal method is landfilling for 60% and co-incineration for 40% of the observed WWTPs in Croatia. The lowest CO2 emissions are obtained with landfilling and mono-incineration in 53% and 38% of the cases, respectively.

scholarly journals Co-Pyrolysis of Coal/Biomass and Coal/Sewage Sludge Mixtures

1998 ◽  
Author(s):  
Christian Storm ◽  
Helmut Rüdiger ◽  
Hartmut Spliethoff ◽  
Klaus R. G. Hein
Keyword(s):  
Heavy Metals ◽  
Organic Matter ◽  
Sewage Sludge ◽  
Fossil Fuels ◽  
Flow Reactor ◽  
Mineral Elements ◽  
Hard Coal ◽  
Coal Pyrolysis ◽  
Pyrolysis Gas ◽  
Entrained Flow Reactor

Biomass and sewage sludge are attracting increasing interest in power plant technology as a source of carbon dioxide-neutral fuels. A new way to reduce the consumption of fossil fuels could be the co-combustion or co-gasification of coal and biomass or coal and sewage sludge. In both cases, pyrolysis is the first step in the technical process. In order to obtain detailed information about the pyrolysis of coal/biomass and coal/sewage sludge mixtures as well as unblended fuels, the ‘Institut für Verfahrenstechnik und Dampfkesselwesen (IVD)’ at the University of Stuttgart has carried out investigations using an electrically heated entrained flow reactor. One application of substitution of fossil fuels could be the utilization of pyrolysis gas or gas generated in a gasification process as a reburn fuel in conventional boilers fired with fossil fuels. Investigation showed that generated gas from coal, biomass and sewage sludge pyrolysis and gasification have high NOx reduction efficiencies compared to methane or low calorific gases using it as a reburn fuel in coal fired boilers. In order to take advantage of this pretreatment process the release of organic as well as of mineral compounds during the pyrolysis or gasification has to be investigated. For coal pyrolysis and gasification the reactions are known since there was a lot of research all over the world. Biomass or sewage sludge have other structures compared to fossil fuels and contain alkali, chlorine and other problematic compounds, like heavy metals. The release of those elements and of the organic matter has to be investigated to characterize the gas and the residual char. The optimum process parameters regarding the composition of the generated gas and the residual char have to be found out. The IVD has studied the co-pyrolysis of biomass and sewage sludge together with a high volatile hard coal. The main parameters to be investigated were the temperature of the pyrolysis reactor (400°C–1200°C) and the coal/biomass and coal/sewage sludge blends. Besides co-pyrolysis experiments test runs with unmixed main fuels were carried out with the hard coal, straw as biomass, and a sewage sludge. It was expected that the high reactivity of biomass and sewage sludge would have an effect on the product composition during co-pyrolysis. The test runs provided information about fuel conversion efficiency, pyrolysis gas and tar yield, and composition of pyrolysis gas and tar. Besides gas and tar analysis investigations regarding the path of trace elements, like heavy metals, alkali, chlorine and nitrogen components, during the pyrolysis process varying different parameters have been carried out. The fuel nitrogen distribution between pyrolysis gas, tar and char has been analyzed as well as the ash composition and thus the release of mineral components during pyrolysis. Increasing reaction temperatures result in a higher devolatilization for all fuels. Biomass shows a devolatilization of up to 80% at high temperatures. Hard coal shows a weight toss of approx. 50% at same temperatures. Sewage sludge devolatilizes also up to 50%, which is nearly a total release of organic matter, because of the high ash content of about 50% in sewage sludge. Gaseous hydrocarbons have a production maximum at about 800°C reaction temperature for all feedstocks. Carbon monoxide and hydrogen are increasingly formed at high pyrolysis temperatures due to gasification reactions. Mineral elements are released during straw pyrolysis, but within the hot gas filtration unit further recombination reactions and condensation of elements on panicles take place. There is no release of mineral elements during sewage sludge pyrolysis and only a slight release of heavy metals at high pyrolysis temperatures. The effect of co-pyrolysis depends on the feedstocks used in association with the panicle size. The co-pyrolysis test runs showed that a synergetic effect exists when using sewage sludge and hard coal. There is a higher char production related to the unmixed fuels; gas and tar formation are lowered. Co-pyrolysis test runs with biomass and coal did not show this effect on the pyrolysis products. Reasons for this behaviour could be a difference in particle size and material structure which influences the devolatilization velocity of the fuels used or the relatively short residence time in the entrained flow reactor. It seems possible that coal pyrolysis is influenced by the reaction atmosphere, generated in co-pyrolysis. In the co-pyrolysis of coal and sewage sludge, the sludge degases much faster than coal because of the structure of sewage sludge and its small panicle. The coal pyrolysis taking place afterwards in the reaction tube occurs in a different atmosphere, compared to the mono-pyrolysis experiments. The devolatilization of coal in the co-pyrolysis experiments together with straw was not disturbed by the gaseous products of straw pyrolysis, because the large straw particles showed a delayed degasing compared to the coal particles.

scholarly journals Eco-Efficiency Assessment of the Application of Large-Scale Rechargeable Batteries in a Coal-Fired Power Plant

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1384 ◽  
Author(s):  
Piotr Krawczyk ◽  
Anna Śliwińska
Keyword(s):  
Power Plant ◽  
Large Scale ◽  
Fossil Fuels ◽  
Economic Benefits ◽  
Fuel Oil ◽  
Electricity Production ◽  
Hard Coal ◽  
Heavy Fuel Oil ◽  
Efficiency Assessment ◽  
The Impact

This article presents the results of an eco-efficiency assessment of the application of large-scale rechargeable battery technology in electricity generation from coal. The eco-efficiency of electricity production in a 350 MW coal-fired power plant was calculated. Two production variants were compared: with the use of a lithium-ion battery of a 400 MWh capacity to optimize the operation of power blocks and without using the battery. Hard coal is one of the main fossil fuels used to generate electricity in Poland. Despite the growing share of electricity from renewable sources, this situation will persist for many more years. The main reasons for this are the high costs and long-lasting process of moving away from fossil fuels in the energy sector. Therefore, any technical solutions that can temporarily reduce the negative impact of coal-based power engineering on the environment should be considered. At the same time, the economic aspects of such solutions must be taken into account. That is why the eco-efficiency assessment method was chosen, which integrates economic and environmental aspects. The obtained results of the analyses indicate the occurrence of environmental and economic benefits resulting from the use of the battery in coal-fired power plants. It has been found that battery-based technology is more eco-efficient than technology without such a battery. A sensitivity analysis was carried out, which allowed the impact of individual computational variables on the eco-efficiency assessment result to be assessed. The results indicate that fuel prices (coal and heavy fuel oil—mazout) and CO2 emission allowances have the greatest impact on the eco-efficiency of the analyzed technology. It was also found that the factors related to the battery, such as its efficiency, life span, decrease of the capacity after 10 years of operation, and construction cost, have a much smaller impact on the results.

Economic Feasibility of Fast Nuclear-Power Merchant Ships

2002 ◽  
Author(s):  
Dmitry V. Paramonov
Keyword(s):  
High Speed ◽  
Nuclear Power ◽  
Fossil Fuels ◽  
Economic Benefits ◽  
Economic Feasibility ◽  
Light Water Reactors ◽  
Fuel Prices ◽  
Merchant Ship ◽  
Water Reactors ◽  
And Performance

Expected doubling of marine trade within the next two decades, threats of global warming amplified by the increased consumption of fossil fuels, globalization of world economy resulting in growing need for rapid ocean transport of time sensitive freight, and recent rise in the fossil fuel prices prompted the Society of Naval Architects and Marine Engineers (SNAME) to initiate a study to examine power plant options for the next generation of high-speed merchant ships. Emerging nuclear power technologies, which might be applicable to such ships, including long core life light water reactors, heavy liquid metal cooled reactors, and gas cooled reactors are discussed. Results of a study comparing economic benefits of nuclear and conventional gas turbine merchant ship propulsion systems are reported. Finally, cost and performance characteristics that would make nuclear power a viable alternative for high-speed merchant ships are identified.

scholarly journals Nitrogen Oxides Emission Reduction using Sewage Sludge Gasification Gas Reburning Process / Obniżenie Emisji Tlenków Azotu Przy Użyciu Procesu Reburningu Gazem Ze Zgazowania Osadów Ściekowych

2015 ◽  
Vol 22 (1) ◽  
pp. 83-94
Author(s):  
Sebastian Werle
Keyword(s):  
Sewage Sludge ◽  
Nitrogen Oxides ◽  
Fossil Fuels ◽  
Main Product ◽  
Power Engineering ◽  
Hard Coal ◽  
Photochemical Smog ◽  
Reduction Efficiency ◽  
The One ◽  
Small Capacity

Abstract Nitrogen oxides can be formed in various combustion systems. Strategies for the control of NOx emissions in hard coal boilers include the primary (during the combustion) and secondary measures (after combustion). Reburning is the one of the most attractive techniques for reducing NOx emissions. In the last several years, reburning technology has been widely studied but almost only in power engineering big load boilers. Nevertheless, NOx emission is an issue that needs to be considered for small capacity boilers as nitrogen oxides resulting from the combustion of any fossil fuels contribute to the formation of acid rain and photochemical smog, which are significant causes of air pollution. Poland is among the largest coal producing country in Europe. Due to this fact, coal fired boilers are very popular in power engineering and also in the municipal sector. Simultaneously, Poland is characterized by the lack of sewage sludge thermal treatment installation. Gasification is considered as a one of the most perspective method of thermal utilization any carbon-containing material. Syngas, which is the main product of gasification, can be used as a supplemental fuel to reduce the consumption of main fuel in boilers, and it has the potential to reduce NOx emissions. The paper proposes to link those two Polish features so the aim of the work is an experimental investigation of the reburning process of sewage sludge gasification gas in a small capacity domestic coal-fired boiler. The results obtained show how the addition of the reburning fuel influences on NOx reduction efficiency

scholarly journals THE GENERAL PRINCIPLES OF WASTE PROCESSING WITH RECOVERY OF THEIR ENERGY POTENTIAL ON THE BASIS OF PLASMA TECHNOLOGIES. PART III. COMPARATIVE ANALYSIS OF THE OXYGEN AND AIR BLOWING INFLUENCE AND THE ROLE OF CALORIFIC CONTENT OF SEWAGE SLUDGE

2018 ◽  
pp. 16-30
Author(s):  
V.A. Zhovtyansky ◽  
E.P. Kolesnikova ◽  
M.V. Yakymovych ◽  
P.A. Seredenko
Keyword(s):  
Sewage Sludge ◽  
Calorific Value ◽  
Waste Processing ◽  
Energy Potential ◽  
Gasification Process ◽  
Calorific Content ◽  
Air Blowing ◽  
The Enthalpy Of Formation ◽  
Plasma Technologies

The issues of determination calorific value as well as the enthalpy of formation of sewage sludge are deeply analyzed further to previous publications. Taking into account this analysis, the indicators, the indicators of the efficiency of the sewage sludge gasification process have been clarified and a comparison of the plasma-steam-oxygen and plasmasteamair gasification technologies has been made. At the same time, on the basis of previous studies, the influence on the efficiency indices of not only ballast nitrogen, but also nitrogen oxides is analyzed. Their concentrations cannot be determined on the basis of simple thermodynamic ratios. Bibl 38, Fig. 6, Tab. 1.

scholarly journals Theoretical and Experimental Analysis on Co-Gasification of Sewage Sludge with Energetic Crops

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1750 ◽  
Author(s):  
Stanislaw Szwaja ◽  
Anna Poskart ◽  
Monika Zajemska ◽  
Magdalena Szwaja
Keyword(s):  
Sewage Sludge ◽  
Thermal Processing ◽  
Mineral Content ◽  
Combustion Engine ◽  
Waste Water Treatment ◽  
Preliminary Investigation ◽  
Calorific Value ◽  
High Energy ◽  
Zone Model ◽  
Gasification Process

As known, dried sewage sludge, is a by-product produced from waste water treatment, contains significant amounts of organic content, and makes up to 60% with overall calorific value from 9 to 12 MJ/kg. Hence, it can be considered as material for thermal processing focusing on heat and power production. Among thermal conversion technologies, gasification is seen as the effective one because it can be easily combined with heat and power cogeneration units. On the other hand, due to high mineral content (40–50%) in the sludge, it is difficult to be gasified and obtain syngas with calorific value satisfactory enough for fueling the internal combustion engine. The dried sludge can be subjected to be gasified at temperature above 850 °C. However, large amounts of mineral content do not provide favorable conditions to obtain this required temperature. Thus, it is proposed to enrich the sewage sludge with biomass characterized with significantly higher calorific value. In the article, co-gasification of sewage sludge and Virginia Mallow—energetic crops was investigated. Results from experimental and numerical investigation have been presented. The dried sewage sludge enriched with Virginia Mallow at a mass ratio of 0/100%, 50/50% and 100/0% in tests and in the range from 0 to 100% for theoretical analysis was applied in order to achieve effective gasification process. As observed, lignocellulosic biomass like Virginia Mallow contains low amounts of mineral content below 2%, which makes it appropriate for thermal processing. It contributes to more stable and efficient gasification process. Additionally, Virginia Mallow caused that the process temperature possible to achieve, was 950 °C. Thus, sewage sludge was mixed with this high-energy component in order to improve the gasification parameters and obtain syngas with higher calorific value. A zero-dimensional, two-zone model was developed with aid of the POLIMI kinetics mechanism developed by CRECK Modeling Group to simulate gasification of low calorific substances enriched with high calorific biomass. Obtained results showed that sewage sludge can be completely gasified at presence of Virginia Mallow. Syngas calorific value of approximately 5 MJ/Nm3 was produced from this gasification process. The maximal percentage of Virginia Mallow in the mixture with the sewage sludge was set at 50% due to economic aspects of the technology. It was found, that satisfactory conditions for effective gasification were achieved at this 50/50% percentage of sewage sludge and Virginia Mallow. Potential intensity of gasification was predicted from this 0-D 2-zones model, which calculates area of reduction zone to area of combustion zone. This reduction-to-combustion area ratio for the sewage sludge-Virginia Mallow mixture was estimated at value of 2. Finally, the model was successfully verified with results from tests, hence it was proposed as a tool for preliminary investigation on poor fuels gasification.

Municipal Solid Waste Characteristic and Energy Potential in Piyungan Landfill

2020 ◽  
Vol 898 ◽  
pp. 58-63
Author(s):  
Adolf Leopold S.M. Sihombing ◽  
Ragil Darmawan
Keyword(s):  
Anaerobic Digestion ◽  
Potential Energy ◽  
Landfill Gas ◽  
Calorific Value ◽  
Economic Feasibility ◽  
International Standards ◽  
Raw Material ◽  
Energy Potential ◽  
The Right ◽  
Gasification Technology

The daily waste tonnage at Piyungan landfill is 600 tons consisting of organic and combustible waste which can be used as an energy source. The aim of this study is to determine the potential energy of waste in the Piyungan landfill by its characteristics based on technology options including landfill gas, anaerobic digestion, gasification, and incineration. The Piyungan landfill mostly contain organic waste, up to 62.1% and combustible waste (RDF) at 26.8%. Moisture content of Piyungan’s RDF is higher than international standards for RDF as raw material in several countries. The various result for Nett Calorific Value is about 7.27 MJ/kg for fresh waste, 12.78 MJ/kg for RDF, 1.74 MJ/kg for market waste and 4.14 MJ/kg for mining waste. Landfill gas can generate energy up to 1.2 MW at the beginning and reaches 2 MW during peak periods. The potential energy by using anaerobic digestion and gasification technology are 1.54 MW and 3.12 MW. By incinerate fresh waste, the potential energy can be generated up to 9 MW and 4.39 MW when incinerate RDF waste only. Calculation of potential energy can be used as a basis for selecting the right technology, especially for economic feasibility for each technology.

scholarly journals Estimation of Energy and Emissions Properties of Waste from Various Species of Mint in the Herbal Products Industry

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 55 ◽  
Author(s):  
Grzegorz Maj ◽  
Agnieszka Najda ◽  
Kamila Klimek ◽  
Sebastian Balant
Keyword(s):  
Plant Biomass ◽  
Nox Reduction ◽  
Co2 Reduction ◽  
Calorific Value ◽  
Mentha Piperita ◽  
Hard Coal ◽  
Volatile Fraction ◽  
Energy Potential ◽  
Mentha Spicata ◽  
Herbal Products

The paper presents the results of research on the physicochemical properties of plant biomass consisting of four mint species, these being Mentha × piperita L. var. citrata Ehrh.—‘Bergamot’, Mentha × rotundifolia L., Mentha spicata L., and Mentha crispa L. The research conducted consisted of the technical analysis of biofuels—determining the heat of combustion and the calorific value of the material under study, and the content of ash, volatile compounds, and humidity. In addition, elemental analysis was carried out for the biomass under study by determining the content of carbon, hydrogen, nitrogen, and sulfur. The research demonstrated that Mentha × piperita L. var. citrata Ehrh.—‘Bergamot’ had the highest energy potential with a gross calorific value of 16.96 MJ·kg−1, and a net calorific value of 15.60 MJ·kg−1. Among the tested materials, Mentha × rotundifolia L. had the lowest content of ash at 7.23%, nitrogen at 0.23%, and sulfur at 0.03%, and at the same time had the highest content of volatile fraction at 70.36%. When compared to hard coal, the estimated emission factors indicated a CO reduction of 29–32%, CO2 reduction of 28–31%, NOx reduction of 40–80%, SO2 reduction of 92–98%, and dust reduction of 45–61%, depending on the type of biomass used.

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