Life cycle assessment of bio-based sodium polyacrylate production from pulp mill side streams: Case study of thermo-mechanical and sulfite pulp mills

Sodium polyacrylate (Na-PA) is a super absorbent polymer, which is commonly used in diverse hygiene products. The polymer is currently produced from fossil feedstock and its production consequently leads to adverse environmental impacts. Na-PA production from sugars present in pulp mill side streams can potentially be a successful way to achieve a more sustainable production of this polymer. In order to guide the development of a novel biochemical process for producing Na-PA, a life cycle assessment was done in which Na-PA produced from side streams of thermo-mechanical pulp (TMP) and sulfite pulp mills were compared. Furthermore, a comparison was made with Na-PA produced from fossil resources. The results show that the main determinant of the environmental impact of the bio-based Na-PA production is the free sugar content in the side streams. The lowest environmental impact is achieved by the least diluted side streams. More diluted side streams require larger amounts of energy for concentration, and, if the diluted streams are not concentrated, processes such as hydrolysis and detoxification, and fermentation are the environmental hotspots. Furthermore, the higher the yield of the fermentation process, the lower the environmental impact will be. Lastly, the production of bio-based Na-PA led to a lower global warming potential for some of the considered pulp mill side streams, but all of the other impacts considered were higher, when compared to fossil-based Na-PA production. Therefore, in parallel with efforts to develop a high-yield yeast for the fermentation process, technology developers should focus on low energy concentration processes for the side streams

Repair for high‐voltage electric motors: energy efficiency vs resource use?

Electric motors in the industry represent 69% of the industrial electricity consumption in Europe. Even if few in number, high voltage (HV) motors represent a significant share of this consumption due to their more intensive use and high output power. Two main HV motor technologies exist: induction motors (IM) and synchronous motors (SM), of which the latter are more energy efficient. Improving energy efficiency as well as use extension by maintenance, repair or remanufacturing have been identified as relevant circular economy strategies for improving the environmental performance of such active and durable products. However, the assessments performed focus on small- and medium-size electronic products, leaving out bigger products that are more durable and more energy consuming such as HV motors. Those motors are often used until failure, which frequently occurs in stator windings, and which could be repaired by rewinding at the expense of a slight decrease in efficiency. However, other use extension strategies such as reuse and remanufacturing are hindered by the customization of HV motors to their specific use. Finding an appropriate set-up for a second use is difficult for such motors and it is therefore performed seldom. The aim of this study is to compare the life-cycle environmental impact of lifetime extension by repair for the two motor technologies in comparison to their replacement. Please click Additional Files below to see the full abstract

Prospective life cycle assessment of adipic acid production from forest residue

Moving from a fossil-based to a bio-based economy requires the development of novel technologies for the production of bio-based chemicals and materials, and the Swedish forestry sector may play a major role in this. These technologies may become part of novel biorefinery concepts that combine the production of bulk and fine chemicals. This paper presents the life cycle assessment (LCA) of such a technology, in its early stages of development, which targets the biochemical production of adipic acid from Swedish forest residue. Adipic acid is a bulk chemical and its yearly production is approximately 2.3 million tonnes. It is mainly used as a precursor in the production of nylon, and its current fossil-based production process emits significant quantities of nitrous oxide (N2O), a strong greenhouse gas. Preliminary calculations showed that, compared to conventional adipic acid production, eliminating the emission of N2O would lead to a reduction of GWP by 75%, and that switching from a fossil-based to a biomass-based feedstock would reduce GWP by an additional 10%. This LCA focused on the technology for producing adipic acid, but also considered its connection with other technologies in the biorefinery concept. An anaerobic digestion process is used to produce biogas from the waste water. As well, lignin is produced as a by-product. The heat from biogas and lignin incineration can be used to meet the energy demands of the adipic acid production. Lab-scale experimental results were used in the assessment, and scaling up these results to an industrially relevant process capacity was done by using process modelling and simulation. Furthermore, an assessment was done of the impact of extracting forest residue from the Swedish forest. The results of this LCA show that the environmental impacts of producing adipic acid from forest residues, except for acidification potential, are significantly lower than those of its conventional production. The environmental hotspot of the technology is the downstream processing stage due to its need of additional energy which was assumed to be fossil. This additional energy is needed because of the low concentration of adipic acid in the fermentation broth. Further improvements can thus be made by minimizing fossil energy use in this stage, or by aiming for a higher end concentration of adipic acid in the fermentation broth. Lastly, the extraction of forest residue was found to only marginally contribute to global warming

Life cycle assessment of biomass-based ethylene production in Sweden - is gasification or fermentation the environmentally preferable route?

Purpose To reduce its environmental impact, the chemical industry is investigating the biomass-based production of chemicals such as ethylene, including fermentation and gasification conversion processes. However, a comprehensive study that compares the environmental impact of these biomass routes is missing. This study assesses and compares a wood gasification with a wood fermentation route to ethylene in Sweden, as well as compares it with the commercialized sugarcane and fossil oil alternatives. Methods The study followed the methodology of life cycle assessment. A cradle-to-gate perspective for the production of 50,000 t ethylene/year was applied, and the following impact categories were investigated: global warming (GWP), acidification (ACP), photochemical ozone creation (POCP), and eutrophication (EP). Results and discussion Biomass acquisition including transport to the gasification plant was the major cause of the gasification route’s GWP and POCP, suggesting improvements with regard to fuel source and machine efficiency. NOx emissions from the gasification process had the main share on the ACP and EP. The comparison of the gasification with a wood and a sugarcane fermentation route showed a lower impact for the gasification route. Among other things, this is caused by high emissions from transport and cultivation for the sugarcane route and high emissions from enzyme and ethanol production for the wood fermentation route. The results were less distinct for a comparison of the gasification with a fossil-based route. Fossil-based ethylene production was found to be preferable for the ACP and the EP, but less preferable for the GWP and POCP. However, it needs to be considered that the fossil route has been optimized for decades and is still ahead of the gasification and other biomass routes. Conclusions The study shows that a gasification-based production of ethylene could outperform a fermentation-based one; however, further investigations are recommended, given the state of development of the investigated biomass routes. Moreover, based on the limited availability of biomass, further investigations into economical and ecological restrictions are of importance

Developing a MOOC at Chalmers: Motivation and first experiences from a teacher’s perspective

An increasing number of universities around the globe produce and conduct Massive Open Online Courses (MOOCs). Chalmers has followed this trend by starting to develop two MOOCs in 2014. While some research has attempted to assess the learners’ motivations to participate in MOOCs (e.g. Kizilcec et al. 2013), little is known about motivations, opportunities and challenges for teachers engaging in MOOC development. In this presentation, we will reflect upon this question drawing on the Chalmers MOOC “Sustainability in Everyday Life”. The MOOC aims to increase the learners’ capacity to appreciate the complexity of sustainability issues and to apply systems thinking and critical reflection on the information flow in public media. The pedagogical approach attempts to emphasize interactivity between learners with a minimum of teacher involvement. After brief introduction to MOOCs in general and at Chalmers in particular, the aim of this presentation is twofold: 1) from the teacher’s perspective, we share first experiences of developing a MOOC aimed at the general informed public, and 2) we identify issues with importance to pedagogical design, developing material and assessment. This is a first step in an action research program, which will be used to evaluate the benefits and challenges of MOOCs for teachers at Chalmers

Toward a sustainable biorefinery using high-gravity technology

The realization of process solutions for a sustainable bioeconomy depends on the efficient processing of biomass. High-gravity technology is one important alternative to realizing such solutions. The aims of this work were to expand the knowledge-base on lignocellulosic bioconversion processes at high solids content, to advance the current technologies for production of second-generation liquid biofuels, to evaluate the environmental impact of the proposed process by using life cycle assessment (LCA), and to develop and present a technically, economically, and environmentally sound process at high gravity, i.e., a process operating at the highest possible concentrations of raw material. The results and opinions presented here are the result of a Nordic collaborative study within the framework of the HG Biofuels project. Processes with bioethanol or biobutanol as target products were studied using wheat straw and spruce as interesting Nordic raw materials. During the project, the main scientific, economic, and technical challenges of such a process were identified. Integrated solutions to these challenges were proposed and tested experimentally, using wheat straw and spruce wood at a dry matter content of 30% (w/w) as model substrates. The LCA performed revealed the environmental impact of each of the process steps, highlighting the importance of the enzyme dose used for the hydrolysis of the plant biomass, as well as the importance of the fermentation yield

Higher Serum Vitamin D Concentrations Are Longitudinally Associated with Better Global Quality of Life and Less Fatigue in Colorectal Cancer Survivors up to 2 Years after Treatment

BACKGROUND: Vitamin D status may be an important determinant of health-related quality of life of colorectal cancer survivors. The current study investigated longitudinal associations between serum 25-hydroxyvitamin D3 (25OHD3) concentrations and quality of life in stage I-III colorectal cancer survivors up to 2 years after treatment. METHODS: Patients with colorectal cancer (n = 261) were included upon diagnosis. Home visits (including blood sampling) were performed at diagnosis and at 6 weeks, 6 months, 1 year, and 2 years after treatment. Serum 25OHD3 concentrations were measured using LC/MS-MS and adjusted for season. Validated questionnaires were used to assess global quality of life and cognitive functioning (EORTC-QLQ-C30), fatigue (EORTC-QLQ-C30 and Checklist Individual Strength, CIS), and depression and anxiety (Hospital Anxiety and Depression Scale). Statistical analyses were performed using linear mixed models and adjusted for sex, age, time since diagnosis, therapy, comorbidities, physical activity, and body mass index. RESULTS: At diagnosis, 45% of patients were vitamin D deficient (<50 nmol/L). After treatment, 25OHD3 concentrations increased on average with 3.1 nmol/L every 6 months. In confounder-adjusted models, 20 nmol/L increments in 25OHD3 were longitudinally associated with increased global quality of life [β 2.9; 95% confidence interval (CI), 1.5-4.3] and reduced fatigue (EORTC-QLQ-C30 subscale: β -3.5; 95% CI, -5.3 to -1.8 and CIS: β -2.8; 95% CI, -4.7 to -0.9). Observed associations were present both within and between individuals over time. CONCLUSIONS: Higher concentrations of 25OHD3 were longitudinally associated with better global quality of life and less fatigue in colorectal cancer survivors. IMPACT: This study suggests that higher 25OHD3 concentrations may be beneficial for colorectal cancer survivors. Future intervention studies are needed to corroborate these findings

Evaluation of a MOOC on &quot;Sustainability in Everyday Life&quot; -The teachers&apos; experiences

Abstract Universities all over the world have been developing Massive Online Open Courses, MOOCs. In this paper, we discuss our experiences during the production of and running the MOOC &quot;Sustainability in everyday life&quot;, that was developed at Chalmers University of Technology. The MOOC ran over a period of 7 weeks, from early June until late July, 2015 and attracted about 9000 participants. The purpose of this paper is (1) to describe and evaluate the further development and content production, and subsequent running of the course; and (2) to share our experiences of running a MOOC for the first time. An action research approach, that focuses on the experience of the teachers, was combined with information obtained from the course statistics, and from the course evaluations by the participants. This approach was used to identify the challenges that were met during the development of the course material and running the MOOC. The results show that, on the one hand, the major challenges were the planning of the content production process and the formulation of the assignments. On the other hand, although time consuming, the production of the video content was perceived as a nice activity. The course statistics and evaluations by the MOOC participants reflected the teachers&apos; experiences to some extent, and this information can be used to improve the MOOC. The role of MOOCs in higher education for sustainable developmen

Design and early development of a MOOC on "Sustainability in Everyday Life" : role of the teachers

Universities all over the world have developed Massive Online Open Courses (MOOCs) to attract students and explore new ways of learning. The MOOC “Sustainability in Everyday Life” (SiEL) is currently in its design and early development stage at Chalmers University of Technology. It aims at developing the MOOC participant’s capacity to appreciate the complexity of sustainable everyday life by developing skills such as systems thinking and critical reflection on the information flow in public media. This paper aims at sharing first experiences regarding the design and early development of the SiEL MOOC and identifying the role(s) of the teachers and its features during the course design and early development based on these first experiences. An action research approach was used to reach these aims, and the teachers’ narratives about these first experiences were used as data source. Three distinct processes (pedagogical, production and interaction) and six roles (owners, teachers, learners, designers, developers and negotiators) were identified. The teachers’ roles and the processes and activities taking place during the design and early development are closely linked to each other and need to be carefully considered in order to guarantee a successful MOOC design and development process.Non UBCUnreviewedFacultyOthe