Morgan Fröling

Bio-refinery system of DME or CH4 production from black liquor gasification in pulp mills.

There is great interest in developing black liquor gasification technology over recent years for efficient recovery of bio-based residues in chemical pulp mills. Two potential technologies of producing dimethyl ether (DME) and methane (CH(4)) as alternative fuels from black liquor gasification integrated with the pulp mill have been studied and compared in this paper. System performance is evaluated based on: (i) comparison with the reference pulp mill, (ii) fuel to product efficiency (FTPE) and (iii) biofuel production potential (BPP). The comparison with the reference mill shows that black liquor to biofuel route will add a highly significant new revenue stream to the pulp industry. The results indicate a large potential of DME and CH(4) production globally in terms of black liquor availability. BPP and FTPE of CH(4) production is higher than DME due to more optimized integration with the pulping process and elimination of evaporation unit in the pulp mill.

Environmental assessment of supercritical water oxidation and other sewage sludge handling options.

Sustainable development relies on the eco-efficient use of all flows in society; more value created out of each resource unit. Supercritical water oxidation (SCWO) can be used for treatment of wet organic waste. The technology has been under development for over 20 years but has not yet been fully commercialized. SCWO allows for complete oxidation of all organics in sewage sludge and almost complete recovery of the inherent energy, essentially without harmful emissions. In this paper, a life-cycle assessment (LCA) of sewage sludge SCWO (Aqua-Critox) is presented and the results are compared with LCA results for other sludge handling options: agricultural use, co-incineration with municipal solid waste, incineration with subsequent phosphorus extraction (Bio-Con) and sludge fractionation with phosphorus recovery (Cambi-KREPRO). For SCWO, beneficial utilization of the heat of reaction is of crucial importance for the outcome. The electricity consumed by pumping and the nitrous oxide produced are other important parameters. The best sludge handling option from an environmental point of view depends on what aspect is considered more important in the impact assessment. Regarding global warming, the energy recovery methods perform better than agricultural use.

Life Cycle Assessment of the District Heat Distribution System, Part 1: Pipe Production

Goal, Scope and BackgroundDistrict heating, the utilization of centrally produced heat for space heating and domestic hot water generation, has the potential to contribute to the eco-efficient use of energy resources in the parts of the world where space heating is needed. In literature, environmental studies on district heating mainly consider the emissions from heat generation; the environmental impact from the distribution system is seldom discussed. This paper presents a life cycle assessment of the production of district heating pipes, based on a cradle-to-gate life cycle inventory commissioned by the Swedish District Heating Association. No external review has been performed but a reference group of district heating experts familiar with the practice was involved in the choice of cases as well as in reviewing parts of the study.MethodsManufacturing of district heating pipes at Powerpipe Systems AB, Göteborg, Sweden, was studied. Prefabricated polyurethane insulated district heating pipes were considered, with a steel tube and a protective casing made of high-density polyethylene. Production of pipes during the time period 1999–2000 was investigated. The functional unit used in the study is production of one district heating pipe unit. The studied pipes are: a twin pipe of the dimension DN25 (12m long) and single pipes of the dimensions DN25 (12m), DN100 (12m) and DN500 (16m).Results and DiscussionA short description of the inventory, some inventory results and a life cycle impact assessment are presented. Characterizations according to GWP, AP, POCP and resource depletion are given as well as two weightings: EcoIndicator99 and Ecoscarcity. If the life cycle is grouped into ‘Materials production’, ‘Transports’, ‘Manufacturing’ and ‘Waste management’, the ‘Materials production’ gives rise to a dominating part of the environmental impact.Recommendation and PerspectiveTo use materials in the pipes as efficiently as possible is the most important feature in order to reduce the environmental impact from production of district heating pipes. Twin pipes can be a more material efficient solution than single pipes. It is important to make sure that environmental improvements from changes in the pipe production phase are not offset by other effects in the total life cycle of the district heating pipe.

Hydrocarbons in biogas from household solid waste

The components of biogas from source-separated domestic waste were studied for the first major Swedish plant (Sobacken, Boras) in operation. Methane, carbon dioxide and C-6-C-11 hydrocarbons were determined by gas chromatographic methods. The content of methane was found to be just over 70% (v/v). The major polluting hydrocarbon in the biogas was p-cymene. It may be formed by rearrangement and dehydrogenation of limonene and other monoterpenes in food waste.

Insights from guiding material development towards more sustainable products

Faced with current challenges in society, many companies will need to develop more sustainable products in order to continue operations in the long term. Therefore, ways of identifying important sustainability considerations already in the early stages of material or product development are of importance. The article is based on action research in a material development project. The article provides a description of activities that were performed in the project in order to guide the material development process to enable more sustainable final products, reflections on the lessons learned from this project, and suggestions to similar projects in the form of an overall process based on team learning with the aim of guiding material development towards more sustainable products. The suggested process emphasises the material or product development team’s need to understand which surrounding world and future-oriented considerations will have significant impacts on the specific product’s sustainability performance.

Pictet–Spengler reactions in multiphasic supercritical carbon dioxide/CO2-expanded liquid media. In situ generation of carbamates as a strategy for reactions of amines in supercritical carbon dioxide

Acyl-Pictet-Spengler cyclizations can be achieved in scCO2/CO2-expanded liquid media via the in situ formation of carbamate derivatives of beta-arylethylamines.

Involvement of Advanced Level Students Using Ecological Modelling in Research About Regional Sustainability

Higher education campuses are seen as one of society’s valuable resources for facing sustainability challenges in the urban context. However, one of the main challenges in the design of sustainable and liveable campus is to achieve comprehensive planning schemes that ensure the commitment of the Master Plan to the stakeholders. The paper reviews a specific methodology built on an inter-disciplinary approach basis, which includes a public participation process for creating a model of sustainable campus at the University of Cantabria, Spain. Traditionally, strategic planning on university campuses has been based on limited sectorial perspectives, which should be modified in order to meet new goals outlined in “The People’s Sustainability Treaty on Higher Education”. With traditional planning methods, stakeholders’ contribution is reduced to the participation of meetings where common intentions are declared. However, coordination with stakeholders in the process must be more tangible and accountable through documents approved by both parties. The article analyses the effectiveness of a Campus Planning methodology through the review of the commitments agreed in common (public documents approved by stakeholders), crossing them with concrete measures designated at the Master Plan. This C. Ribalaygua Batalla (&) Department of Geography, Urban and Regional Planning, Universidad de Cantabria, Santander, Spain e-mail: cecilia.ribalaygua@unican.es C. Ribalaygua Batalla ETSI Caminos, Canales y Puertos, Av. de Los Castros, s/n, Santander, Spain F. García Sánchez EDUC, Universidad de Cantabria, Santander, Spain e-mail: 15492garcia@coam.es

Diffusion of cyclopentane in polyurethane foam at different temperatures and implications for district heating pipes

District heating pipes are usually polyurethane-(PUR)-insulated and the outside is protected by a polyethylene (HDPE) casing. The permeability of the cell gases (oxygen, nitrogen, carbon dioxide and cyclopentane) in the PUR foam and in the HDPE casing was determined for a temperature range of 20–60 C (PUR) and 5–40 C (HDPE). From the results, it was concluded that the casing acts as the main diffusion barrier for carbon dioxide, oxygen and nitrogen, whereas the main diffusion barrier for diffusion of cyclopentane is due to the PUR foam. This conclusion is valid for district heating pipes of small to medium dimensions.

Transport of 1,1,1,3,3-pentafluorobutane (HFC-365mfc) in rigid polyurethane foam and polyethylene

This study focuses on the mass transfer properties of 1,1,1,3,3-pentafluorobutane (HFC-365mfc) in the insulating system used in most district heating pipes produced today, namely rigid polyurethane (PUR) foam with a protective layer of polyethylene (HDPE). The solubility, permeability and diffusion coefficients for HFC-365mfc in PUR foam and HDPE have been determined. The coefficients for HFC-365mfc in PUR foam are very similar to those of cyclopentane, currently the most common blowing agent in PUR foams used for district heating pipes in Europe. The polyethylene casing is a better diffusion barrier for HFC-365mfc than it is for cyclopentane. However, the main mass transfer resistance of HFC-365mfc in a district heating pipe is found in the PUR foam.

The polyethylene casing as diffusion barrier for polyurethane insulated district heating pipes

Most district heating pipes are insulated with polyurethane foam in order to minimise heat losses. A high-density polyethylene (HDPE) casing protects the insulated pipe, and its permeability properties for the polyurethane cell gases, including air, play an important role for the long-term insulating capacity. The permeability of the HDPE casing of a district heating pipe was studied. Two methods were used to determine the permeability: I) by measuring the mass transfer through a sample, and II) by measuring the sorption and desorption of the gas in a sample. The experimental procedures are described. For carbon dioxide a permeability coefficient of about 9·10-16 mole·m-1·s-1·Pa-1 was found by both methods. For oxygen and nitrogen only method I was used and the permeability coefficients found were 1.9 and 0.6·10-16 mole·m-1·s-1·Pa-1, respectively.