Two-in-One Fuel Synthetic Bioethanol-Lignin from Lignocellulose with Sewage Sludge and Its Air Pollutants Reduction Effects

Developing effective, economical, and environmentally sound approaches for sewage sludge management remains an important global issue. In this paper, we propose a bioethanol-lignin (nonfood biomass)-based sewage sludge upgrading process for enhancing the heating value and reducing air pollutants of hybrid sewage sludge fuel (HSF) for the effective management of sewage sludge. Sewage sludge paste with the lignin-CaO solution implies drying at 105 °C accompanied by torrefaction at 250 °C. During torrefaction, moisture and partly volatile matter begin to evaporate, and are almost vaporized out to the surface. In this study, the proposed process enhances the net caloric value (NCV) to 37%. The lignin-embedded HSF shows a two-in-one combustion peak regardless of the mixing ratio, resulting in a 70% reduction of unburned carbon (UBC) emissions, which is one of the particular matter (PM) sources of combustion flue gas. Other air pollutants, such as CO, hydrocarbon, NOx, and SOx, were also reduced by the proposed process. In particular, SOx emission remained at ~1 ppm (average value) regardless of the sulfur content of the fuel.

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Hydrothermal Carbonization as a Strategy for Sewage Sludge Management: Influence of Process Withdrawal Point on Hydrochar Properties

Energies ◽

10.3390/en13112890 ◽

2020 ◽

Vol 13 (11) ◽

pp. 2890 ◽

Cited By ~ 6

Author(s):

Fabio Merzari ◽

Jillian Goldfarb ◽

Gianni Andreottola ◽

Tanja Mimmo ◽

Maurizio Volpe ◽

...

Keyword(s):

Sewage Sludge ◽

Oxygen Demand ◽

Hydrothermal Carbonization ◽

Volatile Matter ◽

Ash Content ◽

Process Conditions ◽

Conventional Activated Sludge ◽

Phosphorous Content ◽

Sewage Sludge Management ◽

Ph Decrease

Conventional activated sludge systems, still widely used to treat wastewater, produce large amounts of solid waste that is commonly landfilled or incinerated. This study addresses the potential use of Hydrothermal Carbonization (HTC) to valorize sewage sludge residues examining the properties of hydrochars depending on HTC process conditions and sewage sludge withdrawal point. With increasing HTC severity (process residence time and temperature), solid yield, total Chemical Oxygen Demand (COD) and solid pH decrease while ash content increases. Hydrochars produced from primary (thickened) and secondary (digested and dewatered) sludge show peculiar distinct properties. Hydrochars produced from thickened sludge show good fuel properties in terms of Higher Heating Value (HHV) and reduced ash content. However, relatively high volatile matter and O:C and H:C ratios result in thermal reactivity significantly higher than typical coals. Both series of carbonized secondary sludges show neutral pH, low COD, enhanced phosphorous content and low heavy metals concentration: as a whole, they show properties compatible with their use as soil amendments.

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Influence of Acids and Alkali as Additives on Hydrothermally Treating Sewage Sludge: Influence on Phosphorus Recovery, Yield, and Energy Value of Hydrochar

Processes ◽

10.3390/pr9040618 ◽

2021 ◽

Vol 9 (4) ◽

pp. 618

Author(s):

Vicky Shettigondahalli Ekanthalu ◽

Satyanarayana Narra ◽

Jan Sprafke ◽

Michael Nelles

Keyword(s):

Sewage Sludge ◽

Hydrothermal Carbonization ◽

Negative Influence ◽

Proximate Analysis ◽

Phosphorus Recovery ◽

Feed Water ◽

Temperature Dependent ◽

Heating Value ◽

Management Processes ◽

Sewage Sludge Management

The high moisture content present in sewage sludge hinders the use of sewage sludge in incineration or energy application. This limitation of moisture present in sewage sludge can be obviated by using the hydrothermal carbonization (HTC) process. In sewage sludge management, the HTC process requires less energy compared to other conventional thermo–chemical management processes. The HTC process produces energy-rich hydrochar products and simultaneously enables phosphorus recovery. This study investigates the influence of organic acids, inorganic acid, and alkali as additives on phosphorus transformation, yield, proximate analysis and the heating value of subsequently produced hydrochar. The analysis includes various process temperatures (200 °C, 220 °C, and 240 °C) in the presence of deionized water, acids (0.1 M and 0.25 M; H2SO4, HCOOH, CH3COOH), and alkali (0.1 M and 0.25 M; NaOH) solutions as feed water. The results show that phosphorus leaching into the process-water, hydrochar yield, proximate analysis, and the heating value of produced hydrochar is pH- and temperature-dependent, and particularly significant in the presence of H2SO4. In contrast, utilization of H2SO4 and NaOH as an additive has a negative influence on the heating value of produced hydrochar.

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Production of fuels on the basis of sewage sludge through conditioning using high calorific value fractions

Water Practice & Technology ◽

10.2166/wpt.2008.011 ◽

2008 ◽

Vol 3 (1) ◽

Author(s):

Karl-Georg Schmelz ◽

Anja Reipa ◽

Hartmut Meyer

Keyword(s):

Sewage Sludge ◽

Wastewater Treatment Plants ◽

Treatment Plant ◽

Calorific Value ◽

Fluidised Bed ◽

Sludge Treatment ◽

Heating Value ◽

Fine Coal ◽

Used Cars ◽

Plastic Components

Emschergenossenschaft and Lippeverband operate 59 wastewater treatment plants which produce approx. 100,000 Mg TS of sewage sludge each year. Using sludge pressure pipelines, about 60 % of this sludge are transported to the central sludge treatment plant in Bottrop. The digested sludges are conditioned using fine coal and polymers and are dewatered using membrane filters. By adding coal, the heating value of the sludge is raised which enables autothermal combustion of the dewatered sludges in fluidised bed furnaces at the central sludge treatment plant. In order to replace coal, a fossil fuel, as conditioning agent, experiments were conducted using alternative materials with high heating values. The addition of shredder fluff agglomerates proved to be particularly successful. Shredder fluff agglomerates are a residue from the recycling of used cars and are generated in a multistage process (e.g. Volkswagen-SiCon Process) by separating the light shredder fraction (plastic components etc.) from the total shredder fluff. The fibrous material is outstandingly suitable for improving the dewaterability and for sufficiently raising the heating value of the dewatered sludge in order to enable autothermal combustion. Since first experiments showed very positive results, a full-scale long-term test-run will take place in 2007.

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New Approach to the Emission of Flue Gases Caused by Sludge Incineration in the Netherlands

Water Science & Technology ◽

10.2166/wst.1992.0509 ◽

1992 ◽

Vol 25 (4-5) ◽

pp. 307-314 ◽

Cited By ~ 3

Author(s):

A. W. van der Vlies ◽

J. H. B. te Marvelde

Keyword(s):

Sewage Sludge ◽

The Netherlands ◽

Flue Gas ◽

Flue Gases ◽

Gas Purification ◽

Incineration Plant ◽

New Approach ◽

Sludge Incineration ◽

Limited Degree ◽

The Town

Recycling of sewage sludge will soon no longer be possible in The Netherlands, or will be possible only to a very limited degree. For that reason, part of the sewage sludge will have to be incinerated. This will happen particularly in those areas where tipping space is very limited. A sludge incineration plant is planned to be built in the town of Dordrecht, with a capacity of 45,000 tonnes dry solids per year. The plant will be subject to the very strict flue gas emission requirements of the Dutch Guideline on Incineration. The Guideline demands a sophisticated flue gas purification procedure.

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Co-Management of Sewage Sludge and Other Organic Wastes: A Scandinavian Case Study

Energies ◽

10.3390/en14123411 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3411

Author(s):

Clara Fernando-Foncillas ◽

Maria M. Estevez ◽

Hinrich Uellendahl ◽

Cristiano Varrone

Keyword(s):

Anaerobic Digestion ◽

Sewage Sludge ◽

Resource Recovery ◽

Organic Wastes ◽

Industrial Wastes ◽

Wastewater Management ◽

Sewage Sludge Management ◽

The Common ◽

Green Chemicals

Wastewater and sewage sludge contain organic matter that can be valorized through conversion into energy and/or green chemicals. Moreover, resource recovery from these wastes has become the new focus of wastewater management, to develop more sustainable processes in a circular economy approach. The aim of this review was to analyze current sewage sludge management systems in Scandinavia with respect to resource recovery, in combination with other organic wastes. As anaerobic digestion (AD) was found to be the common sludge treatment approach in Scandinavia, different available organic municipal and industrial wastes were identified and compared, to evaluate the potential for expanding the resource recovery by anaerobic co-digestion. Additionally, a full-scale case study of co-digestion, as strategy for optimization of the anaerobic digestion treatment, was presented for each country, together with advanced biorefinery approaches to wastewater treatment and resource recovery.

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