Sustainable Dye Separation from Recycled Textile Wastewater - Environmental and economic analysis of applicable methods
(2024) In TVVR 5000 VVRM05 20232Division of Water Resources Engineering
- Abstract
- The textile industry represents a major economic sector with millions employed. With over 200 trillion litres of water consumed each year, it is responsible for a tenth of global emissions, dwarfing aviation and maritime shipping, combined. The wastewater generated is predominantly non-biodegradable, constituting a complex matrix of various contaminants that have long-lasting effects on aquatic and human life. The need for a closed-loop system is clear, yet little has been done in search of a solution.
This paper presents a review and discussion of the most applicable methods available to mitigate the effects of dyes released into the environment by evaluating dye removal methods of recycled textile wastewater from the world's first... (More) - The textile industry represents a major economic sector with millions employed. With over 200 trillion litres of water consumed each year, it is responsible for a tenth of global emissions, dwarfing aviation and maritime shipping, combined. The wastewater generated is predominantly non-biodegradable, constituting a complex matrix of various contaminants that have long-lasting effects on aquatic and human life. The need for a closed-loop system is clear, yet little has been done in search of a solution.
This paper presents a review and discussion of the most applicable methods available to mitigate the effects of dyes released into the environment by evaluating dye removal methods of recycled textile wastewater from the world's first commercial-scale chemical recycling plant for cellulose-based textiles, namely Renewcell 1 in Sundsvall, Sweden. By designing a process which can simultaneously separate the dye and purify the process water, a reduction in the total environmental impact of Renewcell’s process is achieved. One of the process engineers at Renewcell set the tone of the issue at hand by stressing: “Every kilogram of dye removed from the process loop leads to an improvement in the process”. The result of this solution is not only a reduction in the emission of harmful contaminants to the surrounding environment and possibly a cost mitigation, but a critical concern for the future of their process.
This thesis is theoretical and builds upon the vast amount of research already conducted, in an attempt to distil the most suitable separation method for their process scale. A comprehensive evaluation of the available methods has been made where adsorption is chosen as the most suitable for this application. A comparison of adsorbent materials leads to a preliminary design of an adsorption process using a CaCO3/Ca(OH)2 composite material is suggested as the best solution in terms of the environmental and economic impacts. This design has been conducted with key engineering rules of thumb and justified assumptions to give a close estimate of a real separation process.
The theoretically attainable concentration factor of 9 is indicative of the applicability of liquid adsorption’s feasibility yet the lack of commercially available adsorbents and readily available adsorption columns presents a discrepancy between academic research and practical, scalable solutions. For quantitative results, the scaling of columns needs to be made from lab- through pilot-scale trials. With both the maximum capital and operating costs of the chitosan-based adsorption process, it is highly unfavourable. The CaCO3/Ca(OH)2 composite adsorption process fairs better in comparison to activated carbon in terms of capital costs, but a comparison of the operating costs is difficult to make since the regeneration method for activated carbon is either too expensive or it leads to the destruction of the dye molecules, which the other adsorption processes do not. With capital costs of $134,000 and operating costs of $95,000/year, it shows the most competitive costs of the adsorbents evaluated and a clear route for Renewcell to take in terms of both economic and environmental aspects. (Less) - Popular Abstract
- The textile industry consumes over 200 trillion litres of water consumed each year and is responsible for a tenth of global emissions. The wastewater generated is mostly not biodegradable, containing various contaminants that can have long-lasting effects on the environment. The need for a change is clear.
This paper presents a review and discussion of the most feasible methods available to mitigate the effects of dyes released into the environment by evaluating dye removal methods of recycled textile wastewater from the world's first commercial-scale chemical recycling plant for cellulose-based textiles, namely Renewcell 1 in Sundsvall, Sweden. By designing a process which can simultaneously separate the dye and purify the process... (More) - The textile industry consumes over 200 trillion litres of water consumed each year and is responsible for a tenth of global emissions. The wastewater generated is mostly not biodegradable, containing various contaminants that can have long-lasting effects on the environment. The need for a change is clear.
This paper presents a review and discussion of the most feasible methods available to mitigate the effects of dyes released into the environment by evaluating dye removal methods of recycled textile wastewater from the world's first commercial-scale chemical recycling plant for cellulose-based textiles, namely Renewcell 1 in Sundsvall, Sweden. By designing a process which can simultaneously separate the dye and purify the process water, a reduction in the total environmental impact of Renewcell’s process is achieved. One of the process engineers at Renewcell set the tone of the issue at hand by stressing: “Every kilogram of dye removed from the process loop leads to an improvement in the process”. The result of this solution is not only a reduction in the emission of harmful contaminants to the surrounding environment and possibly a cost mitigation, but a critical concern for the future of their process.
This thesis is theoretical and builds upon the vast amount of research already conducted, in an attempt to distil the most suitable separation method for their process scale. A comprehensive evaluation of the available separation methods has been made where adsorption is chosen as the most suitable for this application. Adsorption involves the adhesion of dye molecules to the surface of particles which can effectively separate the dyes from a liquid stream. A comparison of adsorbent materials leads to a preliminary design of an adsorption process. A calcium composite material is suggested as the best solution in terms of the environmental and economic impacts. This design has been conducted with key engineering rules of thumb and justified assumptions to give a close estimate of a real separation process.
The lack of commercially available adsorbent materials and readily available adsorption units presents a discrepancy between academic research and practical, scalable solutions. For quantitative results, the design of separation units needs to be increased from lab-scale to prove feasible at a larger scale. The costs incurred by an adsorption process are closely related to the adsorbent material and the calcium composite material fairs better in comparison to traditional adsorbent materials in terms of capital costs. This leads to a clear route for Renewcell to take in terms of both economic and environmental aspects. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9148273
- author
- Spångberg, Ludvig LU
- supervisor
- organization
- course
- VVRM05 20232
- year
- 2024
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Feasibility, Wastewater, Indigo, Adsorption, Flotation
- publication/series
- TVVR 5000
- report number
- TVVR-23/5009
- ISSN
- 1101-9824
- language
- English
- additional info
- Examiner: Magnus Larson
- id
- 9148273
- date added to LUP
- 2024-02-12 14:35:50
- date last changed
- 2024-02-12 14:35:50
@misc{9148273,
abstract = {{The textile industry represents a major economic sector with millions employed. With over 200 trillion litres of water consumed each year, it is responsible for a tenth of global emissions, dwarfing aviation and maritime shipping, combined. The wastewater generated is predominantly non-biodegradable, constituting a complex matrix of various contaminants that have long-lasting effects on aquatic and human life. The need for a closed-loop system is clear, yet little has been done in search of a solution.
This paper presents a review and discussion of the most applicable methods available to mitigate the effects of dyes released into the environment by evaluating dye removal methods of recycled textile wastewater from the world's first commercial-scale chemical recycling plant for cellulose-based textiles, namely Renewcell 1 in Sundsvall, Sweden. By designing a process which can simultaneously separate the dye and purify the process water, a reduction in the total environmental impact of Renewcell’s process is achieved. One of the process engineers at Renewcell set the tone of the issue at hand by stressing: “Every kilogram of dye removed from the process loop leads to an improvement in the process”. The result of this solution is not only a reduction in the emission of harmful contaminants to the surrounding environment and possibly a cost mitigation, but a critical concern for the future of their process.
This thesis is theoretical and builds upon the vast amount of research already conducted, in an attempt to distil the most suitable separation method for their process scale. A comprehensive evaluation of the available methods has been made where adsorption is chosen as the most suitable for this application. A comparison of adsorbent materials leads to a preliminary design of an adsorption process using a CaCO3/Ca(OH)2 composite material is suggested as the best solution in terms of the environmental and economic impacts. This design has been conducted with key engineering rules of thumb and justified assumptions to give a close estimate of a real separation process.
The theoretically attainable concentration factor of 9 is indicative of the applicability of liquid adsorption’s feasibility yet the lack of commercially available adsorbents and readily available adsorption columns presents a discrepancy between academic research and practical, scalable solutions. For quantitative results, the scaling of columns needs to be made from lab- through pilot-scale trials. With both the maximum capital and operating costs of the chitosan-based adsorption process, it is highly unfavourable. The CaCO3/Ca(OH)2 composite adsorption process fairs better in comparison to activated carbon in terms of capital costs, but a comparison of the operating costs is difficult to make since the regeneration method for activated carbon is either too expensive or it leads to the destruction of the dye molecules, which the other adsorption processes do not. With capital costs of $134,000 and operating costs of $95,000/year, it shows the most competitive costs of the adsorbents evaluated and a clear route for Renewcell to take in terms of both economic and environmental aspects.}},
author = {{Spångberg, Ludvig}},
issn = {{1101-9824}},
language = {{eng}},
note = {{Student Paper}},
series = {{TVVR 5000}},
title = {{Sustainable Dye Separation from Recycled Textile Wastewater - Environmental and economic analysis of applicable methods}},
year = {{2024}},
}