Excess heat is generated from different industrial processes and from urban infrastructure (sewage water, transport, datacentres and buildings). Thirty-five percent of the European energy demand for heating and cooling could be met by excess heat. Today, however, this energy reserve is barely exploited. There are known barriers to excess heat recovery but limited information on stakeholder interactions in the early stages of excess heat collaborations and on successful collaborations. Sweden is world champion in terms of excess heat recovery into district heating systems, and the country has a long tradition in this field (dating back to the 1970 s). By studying two cases, we shed light on success factors in the early stages and in successful collaborations. We identify that the main success factors for excess heat recovery are (i) trust between the collaborating partners, (ii) the involvement of as many stakeholders across the DH (District Heating) value chain as possible (in the decision-making process), (iii) the establishment of joint goals, and (iv) the identification of a business model allowing for a win-win solution that prioritizes excess heat recovery and secures funding for the necessary investments. Excess heat recovery investments have features similar to those of other investments in climate change mitigation, making the success factors relevant to applications beyond the case of excess heat recovery.
A techno-economic assessment and environmental and social sustainability assessments of novel Fischer–Tropsch (FT) biodiesel production from the wet and dry gasification of biomass-based residue streams (bark and black liquor from pulp production) for transport applications are presented. A typical French kraft pulp mill serves as the reference case and large-scale biofuel-production-process integration is explored. Relatively low greenhouse gas emission levels can be obtained for the FT biodiesel (total span: 16–83 g CO2eq/MJ in the assessed EU countries). Actual process configuration and low-carbon electricity are critical for overall performance. The site-specific social assessment indicates an overall positive social effect for local community, value chain actors, and society. Important social aspects include (i) job creation potential, (ii) economic development through job creation and new business opportunities, and (iii) health and safety for workers. For social risks, the country of implementation is important. Heat and electricity use are the key contributors to social impacts. The estimated production cost for biobased crude oil is about 13 €/GJ, and it is 14 €/GJ (0.47 €/L or 50 €/MWh) for the FT biodiesel. However, there are uncertainties, i.e., due to the low technology readiness level of the gasification technologies, especially wet gasification. However, the studied concept may provide substantial GHG reduction compared to fossil diesel at a relatively low cost.
Excess heat could meet approximately 25% of the heat demand in the European building sector. However, the recovery of excess heat is low, which has been attributed to financial, technical and organisational barriers. There is limited information on the perceived risk exposure of excess heat recovery at different points in time, before undertaking the investment or after having undertaken the investment, and at locations with existing district heating networks or not (greenfield). This is unfortunate because experience can enable new collaborations. In this paper, we compare the perceived risk exposure of four greenfield and two ongoing industrial excess heat recovery collaborations. In doing so, we confirm previously identified barriers, such as difficulty to agree on the value of excess heat, the risk of a single heat source and lack of regulation. We also find that, with experience, changes to the excess heat-generating processes are increasingly important, whereas, greenfield sites find the lack of ‘know-how’ to be risky. However, the main conclusion from this paper is that the risks of industrial excess heat recovery collaborations appear to be over-emphasised. In fact, risk exposure of industrial activity can be reduced through industrial waste heat recovery as excess heat is characterized by limited price fluctuations and new environmental requirements from customers and authorities can be met proactively. Combining experience with a standardised excess heat recovery policy should significantly reduce the risk exposure of new collaborations.
Heat cooperation between industries and district heating companies is often economically and environmentally beneficial. In this paper, energy cooperation between an integrated Swedish pulp and paper mill and two nearby energy companies was analysed through economic optimisations. The synergies of cooperation were evaluated through optimisations with different system perspectives. Three changes of the energy system and combinations of them were analysed. The changes were process integration, extending biofuel boiler and turbine capacity and connection to a local heat market. The results show that the single most promising system change is extending biofuel and turbine capacity. Process integration within the pulp and paper mill would take place through installing evaporation units that yield less excess heat but must in this particular case be combined with extended biofuel combustion capacity in order to be beneficial. Connecting to the local heat market would be beneficial for the pulp and paper mill, while the studied energy company needs to extend its biofuel capacity in order to benefit from the local heat market. Furthermore, the potential of reducing CO2 emissions through the energy cooperation is shown to be extensive; particularly if biofuel and turbine capacity is increased.
Energy supply companies and industrial plants are likely to face new situations due to, for example, the introduction of new energy legislation, increased fuel prices and increased environmental awareness. These new prerequisites provide companies with new challenges but also new possibilities from which to benefit. Increased energy efficiency within companies and increased cooperation between different operators are two alternatives to meet the new conditions. A region characterized by a high density of energy-intensive processes is used in this study to find the economic potential of connecting three industrial plants and four energy companies, within three local district heating systems, to a regional heat market, in which different operators provide heat to a joint district heating grid. Also, different investment alternatives are studied. The results show that the economical potential for a heat market amounts to between 5 and 26 million EUR/year with payback times ranging from two to eleven years. However, the investment costs and the net benefit for the total system need to be allotted to the different operators, as they benefit economically to different extents from the introduction of a heat market. It is also shown that the emissions of CO2 from the joint system would decrease compared to separate operation of the systems. However, the valuation of CO2 emissions from electricity production is important as the difference of emitted CO2 between the accounting methods exceeds 650kton/year for some scenarios.
Through energy efficiency measures, it is possible to reduce heat surplus in the Pulp and paper industry. Yet pulp and paper mills situated in Countries with a heat demand for residential and commercial buildings for the major part of the year are potential heat Suppliers. However, striving to utilize the heat within the mills for efficient energy use Could conflict with the delivery of excess heat to a district heating system. As part of a project to optimize a regional energy system, a sulfate pulp mill situated in central Sweden is analyzed, focusing on providing heat and electricity to the mill and its surrounding energy systems. An energy system optimization method based on mixed integer linear programming is used for studying energy system measures on an aggregated level. An extended system, where the mill is integrated in a regional heat market (HM), is evaluated in parallel with the present system. The use of either hot sewage or a heat PUMP for heat deliveries is analyzed along with process integration measures. The benefits of adding a condensing unit to the back-pressure steam turbine are also investigated. The results show that the use of hot sewage or a heat pump for heat deliveries is beneficial only in combination with extended heat deliveries to an HM. Process integration measures are beneficial and even increase the benefit of selling more heat for district heating. Adding a condensing turbine unit is most beneficial in combination with extended heat deliveries and process integration. Copyright (c) 2007 John Wiley & Sons, Ltd.
The energy use at a Swedish chemical wood-pulp mill is compared internationally and for two model mills that aim to use the most efficient available technology. The international comparison is performed between Canadian and Scandinavian pulp-mills on a general level, and on a closer level among eleven Swedish and Finnish non-integrated sulfate pulp-mills, the type of mill considered in the case study. The two model mills that are used for comparison are one Swedish and one Canadian. The Scandinavian pulp-mills are somewhat more energy efficient than the Canadian mills. Still, the variation in energy use is remarkably large among the Scandinavian mills, which indicates that the energy-saving potential is great. If all Swedish freestanding sulfate pulp-mills became as energy efficient as the most efficient Scandinavian mill, electricity savings corresponding to nearly 1% of the national electricity use would be obtained. In the model mills comparison it was found that large amounts of heat could be saved, particularly in the evaporation plant.
A Swedish wood-pulp mill is surveyed in terms of energy supply and use in order to determine the energy-saving potential. Conservation measures are of increasing interest to Swedish industry, as energy prices have continued to rise in recent years. The electricity price particularly increased after the deregulation of the Scandinavian electricity market in 1996. The deregulation expanded to all of the EU in July 2004, which may increase the Swedish electricity price further until it reaches the generally higher European price level. Furthermore, oil prices have increased and the emissions trading scheme for CO2 adds to the incentive to reduce oil consumption. The energy system at the surveyed pulp mill is described in terms of electricity and process heat production and use. The total energy-saving potential is estimated and some saving points are identified. The heat that today is wasted at the mill has been surveyed in order to find potential for heat integration or heat export. The result shows that the mill probably could become self-sufficient in electricity. Particularly important in that endeavour is updating old pumps.
As a case study, an energy audit was performed at an integrated pulp and paper mill. A top-down approach was applied to identify and categorize the use of electricity, steam and hot water and the results of the audit are presented in this paper. Also, the connections and cooperation with both the nearby district heating system and a local steam deliverer, partly owned by the mill, are described. Potential ways to save energy are pointed out and changes in the cooperation are discussed. Moreover, a discussion of how the system can benefit from the taxation structure is presented, as the design of the studied system, in combination with the introduction of tradable green certificates, creates possibilities to exploit such benefits. As a result from this design it is shown that the introduction of these certificates promotes the use of oil to produce electricity.