This study examines the ecological impact of exemplary processes for the feedstock recycling of waste fractions. It is shown that the material process efficiency of gasification and pyrolysis has a low impact on the greenhouse gas balance in the short term, but that high product yields are necessary in the long term to avoid an increasing climate impact. In a systemic context, different process routes of syngas and pyrolysis oil utilization are compared, and their efficiency and quantitative potential for greenhouse gas reduction compared to electricity-based alternatives of process direct heating of conventional processes and electrolysis-based process chains are classified. It is shown that direct utilization options with few process steps are ecologically more efficient. Feedstock recycling shows a similar reduction potential to direct heating, while the use of electrolysis-based process chains is inefficient but necessary to achieve systemic climate neutrality.:1. Introduction and outline 1
2. Life cycle assessment methodology 5
2.1. Previous LCA investigation on feedstock recycling 7
2.2. Assessment scope 9
2.3. Attributional vs. consequential LCI modelling 11
2.4. Inventory modelling consistency 12
2.5. Prospective technology assessment 13
2.6. Conclusions for the applied methodology 14
3. Process description and modelling 16
3.1. Feedstock recycling technologies 18
3.1.1. Gasification 18
3.1.2. Syngas conditioning and purification 23
3.1.3. Pyrolysis 29
3.1.4. Pyrolysis oil hydroprocessing 32
3.2. Chemical production technologies 34
3.2.1. Steam cracking 35
3.2.2. Catalytic reforming 37
3.2.3. Olefin and BTX recovery 38
3.2.4. Conventional syngas production 41
3.2.5. Methanol and methanol-based synthesis 43
3.2.6. Ammonia synthesis 48
3.3. Electric power integration options 49
3.4. Conventional waste treatment processes 53
3.4.1. Mechanical biological treatment and material recovery 54
3.4.2. Waste incineration 57
3.5. Utility processes and process chain balancing 59
3.6. Electricity and heat supply modelling 65
4. Individual assessment of feedstock recycling processes 68
4.1. Goal and scope definition 68
4.2. Life cycle inventory 68
4.3. Impact assessment 72
4.4. Interpretation 80
5. System-based assessment of feedstock recycling processes 82
5.1. Goal and scope definition 82
5.2. Life cycle inventory 86
5.2.1. Utility, background system inventory and system integration 88
5.2.2. Assessment scenario definition and parameter variation 90
5.3. Impact assessment 93
5.3.1. Framework Status Quo (FSQ) 93
5.3.2. Framework Energy Integration (FEI) 99
5.4. Interpretation 106
6. Summary and conclusion 109
6.1. Results 110
6.2. Recommendations and outlook 111
References 113
Supplementary Material 136
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:88946 |
| Date | 06 February 2024 |
| Creators | Keller, Florian |
| Contributors | Meyer, Bernd, Grunwald, Armin, Technische Universität Bergakademie Freiberg |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:doctoralThesis, info:eu-repo/semantics/doctoralThesis, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
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