Location Based Solutions for Thermal Sewage Sludge Utilization

Transcription

1 Location Based Solutions for Thermal Sewage Sludge Utilization Current Projects at EVN / WTE / S2E IRRC - Waste to Energy October 1 and 2, 2018 Dipl.-Ing. Dr.techn. Thomas Gröbl

2 EVN / WTE / sludge2energy S2E 2

3 EVN / WTE / sludge2energy S2E 3

4 Why do we need thermal treatment of sewage sludge? Change in the disposal practice of sewage sludge. Increasing demands on the quality of sewage sludge for agricultural use (hygiene standards, heavy metals). Restrictions from food producers (e.g. AMA quality label). Direct agricultural application and composting is increasingly considered critical (microplastics, hormones, substances with endocrine effects, pathogens, pharmaceutical residues, artificially produced nanomaterials). Limits regarding substances, soils and direct application quantities. Restriction / elimination of conventional disposal methods. Federal waste management plan Austria (BAWP 2017). Until to 85 % of the municipal sewage sludge should undergo phosphorus recycling. Sewage sludge ordinance GER (AbfKlärV). 4

5 Why do we need thermal treatment of sewage sludge? Creating the conditions for phosphorus recovery from sewage sludge ashes cycle closure. Statistical range of phosphorus about 300 years (85 90 % are spread over Morocco, Western-Sahara, China, Algeria, Syria, South Africa). Increasing contamination of raw phosphate with uranium and cadmium. Europe is strongly dependent on phosphorus imports. In May 2014 the European Commission classified phosphorus as a critical resource. Recycling of phosphorus to minimize the dependency on supplier Theoretical substitution potential of mineral fertilizer ~ 40 % in Austria. Mono incineration with phosphorus recovery from the ashes obtains the highest recovery rates. 5

6 Why do we need thermal treatment of sewage sludge? Minimization of pollutants. Destruction of organic pollutants, germs, hormones, endocrine disruptors, etc. due to high combustion temperatures. Defined and secured pollutant sinks. Minimization of disposal costs. Reduction of volume and mass. Utilization of combustion heat. Utilization of potential synergy effects is essential (site selection). 6

7 Fuel characteristics of dewatered sewage sludge Municipal, dewatered sewage sludge Water Ash Organic % %DS %DS Drysubstance (DS) Schematic representation of the components of dewatered sewage sludge Low calorific fuel. Calorific value (LHV) depending on organic and water content. LHV MJ/kg Self sufficient combustion for LHV (3.5) MJ/kg. Reason: Energy intensive evaporation of water. Measures for increasing calorific value are necessary. 7

8 Fuel characteristics of dewatered sewage sludge 100% 80% 60% 40% Water Ash / Inert Organic 20% 0% Dewatered Sludge Waste Coal Qualitative comparison of the fuel composition of dewatered sewage sludge, waste and hard coal based on the immediate analysis 8

9 Selection of the plant configuration Framework conditions Local, site-specific framework conditions Customer requests and specifications Potential synergies from existing infrastructure and personnel Internal / external sludge Location based restrictions (building site, building height, etc.) Technical framework conditions Plant size / sludge capacity Sludge quality and impurities Drying concept Possibility for discharge or treatment of exhaust vapours Flue gas treatment Economic framework conditions Sludge disposal costs Residue disposal costs Waste heat utilization / electricity generation Investment costs Operating costs Legal framework conditions Emission limit values Traffic Environment Occupational safety and fire protection Technical guidelines and standards 9

10 Selection of the plant configuration Framework conditions Local, site-specific framework conditions Customer requests and specifications Potential synergies from existing infrastructure and personnel Internal / external sludge Location based restrictions (building site, building height, etc.) Economic framework conditions Sludge disposal costs Residue disposal costs Waste heat utilization / electricity generation Investment costs Operating costs Technical framework conditions Plant size / sludge capacity Sludge quality and impurities Drying concept Possibility for discharge or treatment of exhaust vapours Flue gas treatment The question concerning an optimal plant and process configuration is subject to a large number of influencing factors and boundary conditions and cannot be answered generally. Legal framework conditions Emission limit values Traffic Environment Occupational safety and fire protection Technical guidelines and standards 10

11 Sludge treatment plant Dürnrohr Owner/Operator: EVN Wärmekraftwerke GmbH Description: Project data: Status: Reconstruction and optimization of the existing demonstration plant into a sewage sludge treatment plant. 1 combustion line without drying 20,000 t/a dewatered sewage sludge 6,000 12,000 t/a auxiliary fuel 5.0 MW fuel thermal power Positive approval notification exists Summary: At the site in Dürnrohr an existing pyrolysis demonstration plant is planned to be reconstructed into a thermal sludge utilization plant. The sludge is directly dried in the fluidized bed furnace. The required energy for the evaporation of water is provided by the addition of high calorific auxiliary fuel. Self sufficient incineration can be guaranteed. The plant is incorporated into the existing energy network Dürnrohr. The combustion heat is to be used for generation of steam which is fed into the low-pressure steam collector of the energy network. Sludge treatment plant Dürnrohr, 3D-model 11

12 Sludge treatment plant Dürnrohr Situation on site Energy network Dürnrohr Coal-fired Power Plant Dürnrohr (PPD) Waste Treatment Plant Dürnrohr (WTPD) Demonstration Plant / Sludge Treatment Plant Steam line WTPD to PPD (ca. 300 m) 12

13 Sludge treatment plant Dürnrohr Existing demonstration plant Demonstration plant and coal-fired power plant, View east Demonstration plant, View east Demonstration plant, View west Demonstration plant, 3D-Model 13

14 Sludge treatment plant Dürnrohr Framework conditions Concept is significantly influenced by the existing demonstration plant and infrastructure, the energy network as well as the existing permits. As many plant components as possible should be reused. Incorporation into the existing energy network. Maximize steam production. No sewage treatment plant for initiation of vapours from the drying process. External sludge delivered by road. Sludge treatment plant Dürnrohr, 3D-model 14

15 Sludge treatment plant Dürnrohr Plant configuration Sludge treatment plant Dürnrohr, Schematic process flow diagram 15

16 Sludge treatment plant Halle-Lochau Owner/Operator: WTE Betriebsgesellschaft Planning and construction by sludge2energy Description: Project data: Planning, construction and operation of a sewage sludge treatment plant in Halle-Lochau (GER). 1 combustion line with sludge drying 33,300 t/a dewatered sewage sludge 2,750 t/a dried sewage sludge approx. 3.5 MW fuel thermal power approx. 250 kw gross electrical output Status: Positive approval notification expected for Dec Scheduled operation July 2020 Summary: The project consists of planning, construction and operation of a sewage sludge treatment plant in Halle-Lochau, in the area of Leipzig. The site is located at the Kreislauf- und Ressourcenwirtschaftspark Halle-Lochau. The plant design data comply with the requirements for a simplified submission according to 19 BImSchG. A sewage-free drying system and electricity generation are implemented. Sludge treatment plant Halle-Lochau, Plant concept 3D-model 16

17 Sludge treatment plant Halle-Lochau Framework conditions Stand-alone plant on the green-field. No sewage treatment plant for initiation of vapours from the drying process. External sludge: dewatered / fully dried. Plant design data comply with the requirements for a simplified procedure according to 19 BImSchG. Capacity limits: Capacity of the drying unit < 50 t/d and Capacity of the fluidized bed incinerator < 3 t/h. High rating of electrical energy. Sludge treatment plant Halle-Lochau, Plant concept 3D-model 17

18 Sludge treatment plant Halle-Lochau Plant configuration Sludge treatment plant Halle-Lochau, Schematic process flow diagram 18

19 Sludge treatment plant Tubli Customer: Description: Project data: Status: Ministry of Works of the Kingdom of Bahrain Planning, construction and operation of sewage sludge treatment plant in Tubli (Bahrain). 2 combustion lines with sludge drying approx. 165,000 t/a dewatered sewage sludge approx. 2 x 7.5 MW fuel thermal power approx. 1,700 kw gross electrical output Contract with the customer signed Scheduled operation September 2021 Site Summary: The project includes the extension of the major waste-water treatment plant in Tubli. It comprises planning, construction and operation of a sewage sludge treatment plant. The sludge treatment plant is ideally integrated in the waste-water treatment plant and synergies for heating and material flow are used. 19

20 Sludge treatment plant Tubli Framework conditions Expansion of Tubli sewage treatment plant (STP) from 200, ,000 m³ per day. Thermal utilization of the amount of sludge produced in the STP. Integration into the waste-water treatment plant. Maximize availability and flexibility. Condensation of vapours from the drying process with heat recovery. Return and initiation of vapour condensate into the sewage treatment plant. Plant layout: sludge utilization plant 20

21 Sludge treatment plant Tubli Plant configuration Sludge treatment plant Tubli, Schematic process flow diagram 21

22 Summary Thermal treatment of sewage sludge. Change in the disposal practice of sewage sludge and elimination of disposal routes. Creating the conditions for phosphorus recovery from sewage sludge ashes cycle closure. Minimization of pollutants and disposal costs. Selection of the plant configuration strongly depends on framework conditions. Question concerning optimal plant configuration can by no means be answered generally. Optimal plant and process configuration is subject to a large number of influencing factors and boundary conditions. 22

23 Thank you for your kind attention! 23