scholarly journals Optimisation of the co-combustion of meat–bone meal and sewage sludge in terms of the quality produced ashes used as substitute of phosphorites

2020 ◽  
Author(s):  
Zygmunt Kowalski ◽  
Marcin Banach ◽  
Agnieszka Makara
Keyword(s):  
Sewage Sludge ◽  
Circular Economy ◽  
Combustion Process ◽  
Raw Material ◽  
Cadmium Content ◽  
Bone Meal ◽  
High Quality ◽  
Fluorine Compounds ◽  
Production Complex ◽  
Meat Bone Meal

Abstract To obtain a high-quality phosphorus raw material comparable in quality to the best phosphorites used in the fertiliser industry, an analysis was carried out to determine the optimal mass proportions of a meat–bone meal and sewage sludge mixture to be used in a co-combustion process. The ashes obtained contained hydroxyapatite that could be considered a high-quality substitute for phosphorites, with an average P2O5 content of 33.5%. These ashes do not contain fluorine compounds, cadmium content is at trace levels and they do not contain the radioactive compounds that are present in trace amounts in all phosphates. The developed process is an example of a production complex using cleaner technologies and circular economy principles on a microeconomic scale.

scholarly journals Evaluating the Potential for Combustion of Biofuels in Grate Furnaces

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1951 ◽  
Author(s):  
Małgorzata Wzorek
Keyword(s):  
Sewage Sludge ◽  
Combustion Process ◽  
Pollutant Emissions ◽  
Biomass Combustion ◽  
Municipal Sewage Sludge ◽  
Hard Coal ◽  
Meat And Bone Meal ◽  
Bone Meal ◽  
Coal Slime ◽  
The Impact

The paper assesses the impact of combustion of biofuels produced based on municipal sewage sludge in stoker-fired boilers on the amount of pollutant emissions and examines the tendency of ash deposition of biofuels formed during the combustion process. The combustion tests were performed in a laboratory system enabling simulation of a combustion process present in stoker-fired boilers. The study was conducted for three types of biofuels; i.e., fuel from sewage sludge and coal slime (PBS fuel), sewage sludge and meat and bone meal (PBM fuel) and fuel based on sewage sludge and sawdust (PBT) with particle size of 35 mm and 15 mm. This paper describes and compares the combustion process of biofuels with different granulation and composition and presents the results of changes in emission values of NOx, SO2, CO, and CO2. The emission results were compared with the corresponding results obtained during combustion of hard coal. The results showed that biofuels with lower particle sizes were ignited faster and the shortest ignition time is achieved for fuel based on sewage sludge and coal slime-PBS fuel. Also, the highest NO and SO2 emissions were obtained for PBS fuel. During the combustion of fuel based on sewage sludge and meat and bone meal (PBM), on the other hand, the highest CO2 emissions were observed for both granulations. Biofuels from sludge show a combustion process that is different compared to the one for hard coal. The problems of ash fouling, slagging, and deposition during biofuels combustion were also identified. The tendency for ash slagging and fouling is observed, especially for fuel from sewage sludge and meat and bone meal (PBM) and fuel based on sewage sludge and sawdust (PBT) ashes which consist of meat and bone meal and sawdust which is typical for biomass combustion.

Compost from sewage sludge – a product with quality assurance system

2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Martin Kranert ◽  
Gerold Hafner ◽  
Ingrid Berkner ◽  
Ertugrul Erdin
Keyword(s):  
Quality Assurance ◽  
Sewage Sludge ◽  
Raw Material ◽  
Process Conditions ◽  
Quality Assurance System ◽  
Organic Substances ◽  
High Quality ◽  
Assurance System ◽  
Secondary Raw Material ◽  
Sludge Composting

While composting of separate collected bio-waste is currently undergoing a renaissance in Germany, sewage sludge composting offers as well the possibility to produce a hygienic soil conditioner and/or secondary raw material fertilizer. This alternative is increasingly interesting, especially to bring back nutrients and organic substances into soils. This paper explains the essential reasons for composting, shows the process conditions and the different composting processes used currently in Germany. The discussion about the heavy metal problem and the production of a high quality fair marketable product leads to the necessity of a quality assurance system, which has been proven to be effective for bio-waste composting in Germany. The necessary boundary conditions and demands for such a quality assurance system for sewage sludge are presented.

TECHNOLOGICAL ASPECTS OF HIGH QUALITY RAW MATERIAL OBTAINING FOR PECTIN PRODUCTION

1970 ◽  
pp. 47-50
Author(s):  
I. A. Ilina ◽  
I. A. Machneva ◽  
E. S. Bakun
Keyword(s):  
Raw Materials ◽  
Thermal Characteristics ◽  
Environmental Safety ◽  
Raw Material ◽  
High Quality ◽  
Temperature Conductivity ◽  
Drying Temperature ◽  
Plant Raw Materials ◽  
Gel Forming Ability

  The article is devoted to the study of the chemical composition, physical and thermal-pfysical characteristics of damp apple pomaces and the identifying patterns of influence of drying temperature the functional composition and gel-forming ability of pectin. The research is aimed at obtaining initial data for the subsequent calculation of the main technological, hydro-mechanical, thermal, structural and economic characteristics of devices for drying the plant raw materials, ensuring the environmental safety and high quality of pectin-containing raw materials, the reducing heat and energy costs. As a result of the study of the thermal characteristics of apple pomaces, the critical points (temperature conductivity – 16.5 x 10-8 m2/s, thermal conductivity – 0.28 W/m K, heat capacity – 1627 j/(kg K)) at a humidity of 56 % are determined, which characterizing the transition from the extraction of weakly bound moisture to the extraction of moisture with strong bonds (colloidal, adsorption). It was found that the pomaces obtained from apples of late ripening have a higher content of solids (21-23 %), soluble pectin and protopectin (2.5-4.5 %). Dried pomaces obtained from apple varieties of late ripening contain up to 25 % pectin, which allow us to recommend them as a source of raw materials for the production of pectin. The optimum modes of preliminary washing of raw materials are offered, allowing to the remove the ballast substances as much as possible. It is established that when the drying temperature increases, the destructive processes are catalyzed: the strength of the pectin jelly and the uronide component and the degree of pectin esterification are reduced. The optimum drying temperature of damp apple pomaces is 80 0C, at which the quality of pectin extracted from the dried raw materials is maintained as much as possible. It is shown that the most effective for the pectin production is a fraction with a particle size of 3-5 mm, which allow us to extract up to 71 % of pectin from raw materials.

scholarly journals Tagasaste, leucaena and paulownia: three industrial crops for energy and hemicelluloses production

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Alberto Palma ◽  
Javier Mauricio Loaiza ◽  
Manuel J. Díaz ◽  
Juan Carlos García ◽  
Inmaculada Giráldez ◽  
...  
Keyword(s):  
Activation Energy ◽  
Acid Hydrolysis ◽  
Energy Production ◽  
Combustion Process ◽  
Operating Conditions ◽  
Raw Material ◽  
Energy Of Combustion ◽  
Increasing Temperature ◽  
Hydrolysis Of ◽  
Chamaecytisus Proliferus

Abstract Background Burning fast-growing trees for energy production can be an effective alternative to coal combustion. Thus, lignocellulosic material, which can be used to obtain chemicals with a high added value, is highly abundant, easily renewed and usually inexpensive. In this work, hemicellulose extraction by acid hydrolysis of plant biomass from three different crops (Chamaecytisus proliferus, Leucaena diversifolia and Paulownia trihybrid) was modelled and the resulting solid residues were used for energy production. Results The influence of the nature of the lignocellulosic raw material and the operating conditions used to extract the hemicellulose fraction on the heat capacity and activation energy of the subsequent combustion process was examined. The heat power and the activation energy of the combustion process were found to depend markedly on the hemicellulose content of the raw material. Thus, a low content in hemicelluloses resulted in a lower increased energy yield after acid hydrolysis stage. The process was also influenced by the operating conditions of the acid hydrolysis treatment, which increased the gross calorific value (GCV) of the solid residue by 0.6–9.7% relative to the starting material. In addition, the activation energy of combustion of the acid hydrolysis residues from Chamaecytisus proliferus (Tagasaste) and Paulownia trihybrid (Paulownia) was considerably lower than that for the starting materials, the difference increasing with increasing degree of conversion as well as with increasing temperature and acid concentration in the acid hydrolysis. The activation energy of combustion of the solid residues from acid hydrolysis of tagasaste and paulownia decreased markedly with increasing degree of conversion, and also with increasing temperature and acid concentration in the acid hydrolysis treatment. No similar trend was observed in Leucaena diversifolia (Leucaena) owing to its low content in hemicelluloses. Conclusions Acid hydrolysis of tagasaste, leucaena and paulownia provided a valorizable liquor containing a large amount of hemicelluloses and a solid residue with an increased heat power amenable to efficient valorization by combustion. There are many potential applications of the hemicelluloses-rich and lignin-rich fraction, for example as multi-components of bio-based feedstocks for 3D printing, for energy and other value-added chemicals.

scholarly journals Scenario Analysis for Selecting Sewage Sludge-to-Energy/Matter Recovery Processes

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 276
Author(s):  
Francesco Facchini ◽  
Giovanni Mummolo ◽  
Micaela Vitti
Keyword(s):  
Sewage Sludge ◽  
Scenario Analysis ◽  
Value Chain ◽  
Circular Economy ◽  
Solid Material ◽  
Sludge Treatment ◽  
Sewage Sludges ◽  
Recovery Processes ◽  
Sewage Sludge Treatment ◽  
New Perspective

The sewage sludges are the byproducts of the wastewater treatment. The new perspective of the wastewater value chain points to a sustainable circular economy approach, where the residual solid material produced by sewage sludge treatments is a resource rather than a waste. A sewage sludge treatment system consists of five main phases; each of them can be performed by different alternative processes. Each process is characterized by its capability to recover energy and/or matter. In this paper, a state of the art of the sludge-to-energy and sludge-to-matter treatments is provided. Then, a scenario analysis is developed to identify suitable sewage sludge treatments plants that best fit the quality and flowrate of sewage sludge to be processed while meeting technological and economic constraints. Based on the scientific literature findings and experts’ opinions, the authors identify a set of reference initial scenarios and the corresponding best treatments’ selection for configuring sewage sludge treatment plants. The scenario analysis reveals a useful reference technical framework when circular economy goals are pursued. The results achieved in all scenarios ensure the potential recovery of matter and/or energy from sewage sludges processes.

scholarly journals Towards a Circular Economy Taxation Framework: Expectations and Challenges of Implementation

2021 ◽  
Author(s):  
Leonidas Milios
Keyword(s):  
Circular Economy ◽  
Action Plan ◽  
Policy Instruments ◽  
Policy Instrument ◽  
Detailed Examination ◽  
Raw Material ◽  
The European Union ◽  
Material Resource ◽  
Waste Hierarchy ◽  
Tax Relief

AbstractThe transition to a circular economy is a complex process requiring wide multi-level and multi-stakeholder engagement and can be facilitated by appropriate policy interventions. Taking stock of the importance of a well-balanced policy mix that includes a variety of complementing policy instruments, the circular economy action plan of the European Union (COM(2020) 98 final) includes a section about “getting the economics right” in which it encourages the application of economic instruments. This contribution presents a comprehensive taxation framework, applied across the life cycle of products. The framework includes (1) a raw material resource tax, (2) reuse/repair tax relief, and (3) a waste hierarchy tax at the end of life of products. The research is based on a mixed method approach, using different sources to analyse the different measures in the framework. More mature concepts, such as material resource taxes, are analysed by reviewing the existing literature. The analysis of tax relief on repairs is based on interviews with stakeholders in Sweden, where this economic policy instrument has been implemented since 2017. Finally, for the waste hierarchy tax, which is a novel proposition in this contribution, macroeconomic modelling is used to analyse potential impacts of future implementation. In all cases, several implementation challenges are identified, and potential solutions are discussed according to literature and empirical sources. Further research is required both at the individual instrument and at the framework level. Each of the tax proposals needs a more detailed examination for its specificities of implementation, following the results of this study.

Experimental Parameter Study on Synthesis Gas Production by Steam-Oxygen Fluidized Bed Gasification of Sewage Sludge

2021 ◽  
Vol 11 (2) ◽  
pp. 579
Author(s):  
Max Schmid ◽  
Selina Hafner ◽  
Günter Scheffknecht
Keyword(s):  
Sewage Sludge ◽  
Fluidized Bed ◽  
Experimental Parameter ◽  
Space Velocity ◽  
Phosphate Fertilizer ◽  
Gas Production ◽  
Raw Material ◽  
Parameter Study ◽  
Syngas Production ◽  
Fuels And Chemicals

The conversion of biogenic residues to fuels and chemicals via gasification and synthesis processes is a promising pathway to replace fossil carbon. In this study, the focus is set on sewage sludge gasification for syngas production. Experiments were carried out in a 20 kW fuel input bubbling fluidized bed facility with steam and oxygen as gasification agent. In-situ produced sewage sludge ash was used as bed material. The sensitivity of the key operation parameters gasifier temperature, oxygen ratio, steam to carbon ratio, and the space velocity on the syngas composition (H2, CO, CO2, CH4, CxHy, H2S, COS, NH3, and tars) was determined. The results show that the produced syngas has high H2 and CO concentrations of up to 0.37 m3 m−3 and 0.18 m3 m−3, respectively, and is thus suitable for synthesis of fuels and chemicals. By adjusting the steam to carbon ratio, the syngas’ H2 to CO ratio can be purposely tailored by the water gas shift reaction for various synthesis products, e.g., synthetic natural gas (H2/CO = 3) or Fischer–Tropsch products (H2/CO = 2). Also, the composition and yields of fly ash and bed ash are presented. Through the gasification process, the cadmium and mercury contents of the bed ash were drastically reduced. The ash is suitable as secondary raw material for phosphorous or phosphate fertilizer production. Overall, a broad database was generated that can be used for process simulation and process design.

scholarly journals The Influence of Sewage Sludge Content and Sintering Temperature on Selected Properties of Lightweight Expanded Clay Aggregate

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3363
Author(s):  
Jolanta Latosińska ◽  
Maria Żygadło ◽  
Przemysław Czapik
Keyword(s):  
Sewage Sludge ◽  
Water Absorption ◽  
Apparent Density ◽  
Environmental Sustainability ◽  
Sintering Temperature ◽  
Total Porosity ◽  
Raw Material ◽  
Closed Porosity ◽  
Specific Density ◽  
Sustainability Principles

Wastewater treatment processes produce sewage sludge (SS), which, in line with environmental sustainability principles, can be a valuable source of matter in the production of lightweight expanded clay aggregate (LECA). The literature on the influence of SS content and sintering temperature on the properties of LECA is scarce. This paper aims to statistically evaluate the effects of SS content and sintering temperature on LECA physical properties. Total porosity, pore volume, and apparent density were determined with the use of a density analyzer. A helium pycnometer was utilized to determine the specific density. Closed porosity was calculated. The test results demonstrated a statistically significant influence of the SS content on the specific density and water absorption of LECA. The sintering temperature had a significant effect on the specific density, apparent density, total porosity, closed porosity, total volume of pores, and water absorption. It was proved that a broad range of the SS content is admissible in the raw material mass for the production of LECA.

Biocatalysis and biomass conversion: enabling a circular economy

2020 ◽  
Vol 378 (2176) ◽  
pp. 20190274 ◽  
Author(s):  
Roger A. Sheldon
Keyword(s):  
Circular Economy ◽  
Biomass Conversion ◽  
Raw Material ◽  
Liquid Fuels ◽  
Waste Biomass ◽  
Renewable Biomass ◽  
Precious Metal Catalysts ◽  
Mitigate Climate Change ◽  
Forestry Residues ◽  
The Right

This paper is based on a lecture presented to the Royal Society in London on 24 June 2019. Two of the grand societal and technological challenges of the twenty-first century are the ‘greening' of chemicals manufacture and the ongoing transition to a sustainable, carbon neutral economy based on renewable biomass as the raw material, a so-called bio-based economy. These challenges are motivated by the need to eliminate environmental degradation and mitigate climate change. In a bio-based economy, ideally waste biomass, particularly agricultural and forestry residues and food supply chain waste, are converted to liquid fuels, commodity chemicals and biopolymers using clean, catalytic processes. Biocatalysis has the right credentials to achieve this goal. Enzymes are biocompatible, biodegradable and essentially non-hazardous. Additionally, they are derived from inexpensive renewable resources which are readily available and not subject to the large price fluctuations which undermine the long-term commercial viability of scarce precious metal catalysts. Thanks to spectacular advances in molecular biology the landscape of biocatalysis has dramatically changed in the last two decades. Developments in (meta)genomics in combination with ‘big data’ analysis have revolutionized new enzyme discovery and developments in protein engineering by directed evolution have enabled dramatic improvements in their performance. These developments have their confluence in the bio-based circular economy. This article is part of a discussion meeting issue ‘Science to enable the circular economy'.

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