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Research has revealed the existence of an energy-efficiency gap – the difference between optimal and actual energy end-use, suggesting that energy efficiency can be improved. Energy management (EnM) is a means for improving industrial energy efficiency. However, due to various barriers, the full potential of EnM is not realised. Several studies have addressed drivers and barriers to energy efficiency but few to EnM. This study aims to identify EnM practices, the most important perceived drivers and barriers for EnM, and relations among them in the energy-intensive Swedish pulp and paper industry (PPI), which has the longest experience internationally of practising EnM systems, and has worked according to the standards since 2004. Our results show that, altogether, the PPI works regularly and continuously with EnM, with a clear division of responsibilities. The highest maturity for EnM practices was for energy policy, followed by organization, investments, and performance measurement. The study also shows that communication between middle management and operations personnel has potential for improvement. The most important categories of drivers were economic, whereas for barriers they were organizational. Nevertheless, knowledge-related barriers and drivers were amongst the most important, suggesting that the absorptive capacity for energy issues could be improved. Image 1029 • Energy is managed continuously, with clear policies and responsibilities. • The main drivers are economical while main barriers are organizational. • Knowledge related barriers and drivers are amongst the next most important. • Employees' absorptive capacity for energy issues could be improved. • Link between energy policy and performance measurement could be improved. [ABSTRACT FROM AUTHOR]

Guiding industries to produce in an effective and environmentally sustainable manner has become a key issue for governments around the world. Over the past 15 years, series of regional and industrial development policies have been introduced by the Chinese government. This has influenced the geographical distribution and energy efficiency performance of China’s industries. This paper quantifies the influence of enterprises geographical distribution on energy efficiency improvement in the paper industry and aims at providing some helpful suggestions on industrial development to policy makers. The main results show that, firstly, the paper industry in eastern China shows obvious characteristic of agglomeration. The average location quotient is 1.2278. However, following the industrial and regional development policies, the characteristic of agglomeration is weakening. Secondly, only when agglomeration reaches a certain level (location quotient is above 0.5447) will industrial agglomeration positively impact on industrial energy efficiency improvement (a 1% increase in agglomeration will increase dynamic energy efficiency by at least 0.23%). Thirdly, the regional development policies carried out by the government slow the pace of energy efficiency improvement in China’s paper industry. The empirical results indicate that the government needs to consider regional characteristics and consciously guide industrial enterprises to concentrate in the dominant area. [ABSTRACT FROM AUTHOR]

Abstract This study aims at to make a heuristic analysis of energy efficiency performance of Indian paper industry in a non-parametric production theoretic approach. Using the data for 2004–05 to 2013–14, radial and non-radial variants of DEA were employed to estimate energy saving potential and identify the relative position of paper industry across the states. Preliminary analysis in terms of energy intensity scores showed declining trends of energy intensity over the period of analysis for most of the states except states like Assam, Chhattisgarh, Kerala and Punjab where it does not decline much. Assuming a variable returns to scale (VRS) technology under the conditions of inherent heterogeneity and market imperfection, the slack-based measure (SBM) reported a much higher energy saving potential than reported by other measures in the study. Further by taking scale efficiency into account, the study documented the higher contribution of pure energy inefficiency in explaining the total energy inefficiency within the paper industry relative to scale inefficiency. Finally, the study recommends the propagation of energy efficiency program through a market-based and regulatory mechanism along with consolidation and technological advancement of individual units, in order to tap vast energy saving potential and thereby ensure the growth and environmental sustainability. Highlights • The paper examined the energy efficiency performance of Indian paper industry. • Both radial (BCC) and the non-radial (SBM) measures of energy efficiency, were applied. • BCC measure reported an energy saving potential of 16%. • SBM measure reported an energy saving potential of 24%, higher than BCC measure. • Scale efficiency implied the relatively higher contribution of pure energy inefficiency. [ABSTRACT FROM AUTHOR]

China’s paper industry consumes a lot of energy and emits huge amounts of pollutions. The Chinese government over the past decades has done a lot to promote energy efficiency of the industry. This paper studies the impact of industrial polices to improve energy efficiency. The energy efficiency change is firstly studied under a framework of total factor efficiency. On this basis, different econometric models are built to discuss the detailed energy efficiency characteristics of the paper industry. The main results are as follow: (i) ownership structure did influence the energy efficiency, but the influence is different in different conditions; (ii) energy efficiency of the paper industry can be improved by economies of scale; (iii) market competition can to some extent overcome the motivation and supervision problem that often occur in state-owned companies; (iv) energy price cannot play the role of resource allocation well in China. Finally, based on our findings, some suggestions are provided. [ABSTRACT FROM AUTHOR]

The papermaking industry has developed rapidly in recent years in China. Papermaking is a high-energy-consuming process. Consequently, large-scale paper mills usually have cogeneration systems that supply both electricity and steam for the papermaking process. In China, almost all these cogeneration systems in paper mills are powered by coal combustion, which consumes a large amount of energy and emits large amounts of greenhouse gas. The Integrated Gasification Combined Cycle (IGCC) technology is regarded as a clean and efficient method of coal utilization. In this work, an IGCC process for application in paper mills was designed and modeled. An IGCC coupled with a cascade refrigeration process (CRP) was further proposed in order to reuse the waste heat from the dryer section and improve the energy efficiency of the papermaking process. A paper with a conventional cogeneration system, one with an IGCC cogeneration system, and one with an IGCC coupled with a CRP cogeneration system were analyzed and compared in terms of energy efficiency, capital investment, operational cost, and dynamic payback period. The results showed that the integration of IGCC technology allows paper mills to be more competitive than those featuring conventional cogeneration systems in terms of energy efficiency and operational cost. [ABSTRACT FROM AUTHOR]

The increasing use of recycled paper by the paper industry to support the Green Industry in the Indonesian Pulp and Paper Industry. But technically, there are some disadvantages of recycled fiber usage such as low drainage rate in which boosted the high energy consumption on drying process. As already known, the drying process consumes the highest energy in papermaking. To overcome this problem, the research using the concentrate of endoglucanase Egl-II has done. The steps of research included production of endoglucanase Egl-II; concentration by ultrafiltration method, modification of recycled paper fibers using endoglucanase Egl-II; characterization of paper sheet; and evaluation of energy consumption in drying the sheet of paper. The results showed that endoglucanase Egl-II had increase drainage rate of recycled fiber stock, which indicate by the freeness number. The number had increased by 80 ml CSF (Canadian Standard Freeness) from 190 ml CSF to 270 ml CSF, and fiber retention increased by 0,63% from 99,31% to 99,94%. The dissolved cellobiose test results of recycled fiber stock by the enzyme treatment at low dosage showed that no degradation of cellulose, no change into soluble sugars. Characterization of sheet of paper that has been modified with endoglucanase Egl-II based FTIR spectra showed no change in functional group, SEM results showed on the fiber surface fibrils grow more, and the results of the XRD analysis showed area reduction of amorphous regions is about 6%. The potential for energy efficiency is calculated through thermodynamic approach is about 15%. [ABSTRACT FROM AUTHOR]

Abstract To improve energy efficiency of a Paper & Pulp industry, full capacity utilization of the processing equipment and diverse energy source utilities are promoted, while same time processing of diverse raw materials, meeting of strict processing time requirements, seamless material flow and obtaining required product quality are important concerns to be fulfilled. This is similar to a resources management problem while energy is considered as one of the measurable resources, wherein estimation of energy consumptions is crucial/complicated aspect. Discretized form of energy consumption (approximate energy consumed by unit amount of intermediate products at different intermediate processing stages) concept is utilized here with discrete event simulation for consumed energy estimation/analysis. The research deals with a real time working Paper & Pulp industry resource management problem, wherein overall energy consumption rate and production rate were analyzed for some commonly occurring situation of efficiency reduction of the processing station(s). Energy efficient solutions are evaluated with varying production flow (varying the percentage of raw material) and resources management options (turning on/off paper machines). Energy efficient solution which ensures minimum loss in production rate and minimizes disturbances in material flow is suggested for implementation. [ABSTRACT FROM AUTHOR]

As a mainstream power storage and supply device, batteries are continuously upgraded. The microfluidic fuel cell has great development potential, and the paper-based microfluidic fuel cell is the latest achievement of its lightweight, which can be applied in the field of medical and biological detection. In this work, the cell models with various folding forms and unconventional absorption pads are creatively constructed, then the influence mechanism on cell performance is revealed by numerical simulation. Both transient and steady-state simulation methods are employed to monitor the whole process of paper-based microfluidic fuel cell. Conclusions show that the cell performance decreases with the increase of folding angle, the peak power density is as low as 1.71 mW/cm2, and the corresponding fuel utilization is only 2.73%. The changes in the absorbent pad shapes have little improvement on cell performance, thus the most direct way is increasing the absorbent pad volume. Moreover, materials with better water absorption capacity can increase the maximum current density to 28.70 mA/cm2, and the appropriate increase of operating temperature can also increase the peak power density to 2.36 mW/cm2, but the effect on the cell is significantly weakened if the temperature exceeds a certain limit. [ABSTRACT FROM AUTHOR]

Production of transportation fuels from biorefineries via biomass gasification has been suggested as a way of introducing renewable alternatives in the transportation system with an aim to reduce greenhouse gas emissions to the atmosphere. By co-locating gasification-based processes within heat demanding industries, excess heat from the gasification process can replace fossil or renewable fuels. The objective of this study was to compare the heat integration potential of four different gasification-based biorefinery concepts with a chemical pulp and paper mill. The results showed that the choice of end-product which was either methanol, Fischer-Tropsch crude, synthetic natural gas or electricity, can have significant impact on the heat integration potential with a pulp and paper mill and that the heat saving measures implemented in the mill in connection to integration of a gasification process can increase the biomass resource efficiency by up to 3%-points. Heat saving measures can reduce the necessary biomass input to the biorefinery by 50% if the sizing constraint is to replace the bark boiler with excess heat from the biorefinery. A large integrated gasification process with excess steam utilisation in a condensing turbine was beneficial only if grid electricity is produced at below 30% electrical efficiency. [ABSTRACT FROM AUTHOR]

The Swedish pulp and paper industry (PPI) must increase energy efficiency to remain competitive on the global market, which has experienced entries from countries with cheaper energy and raw material supplies. Interactions among variables for energy use, production, energy management, electricity price and firm characteristics (FC), in different types of mills, i.e., pulp, paper and integrated mills, in Sweden from 2006 to 2015 indicate that correlations among the studied variables were different in different types of mills. This difference between types of mills seemed to originate partly from varying accessibility to production residue that could be used for energy. For all types of mills, variation of electricity prices did not correlate significantly with energy efficiency during the study period. The studied FC were firm's age, number of employees, number of companies in company group, net sales and profit for the year. Energy efficiency was more affected by the variables characterizing energy and production compared to the variables representing FC. This study also suggested presence of possible discrepancies between FC that were perceived as barriers to energy management towards energy efficiency, according to previous studies, and what was shown by the data combining variables representing energy use, production and FC. [ABSTRACT FROM AUTHOR]

Abstract: We examine consequences of new energy technologies in the pulp and paper industry with respect to net CO2 emissions and oil use. The entire production chain from the extraction of primary resources is included in the analysis. Stand-alone production of electricity and transportation fuel from biomass is included to balance the systems compared, so that they produce the same CO2 emission and oil use reductions. The technologies considered are black liquor gasification (BLG) with electricity and motor fuels production in chemical pulp mills and increased energy efficiency in thermomechanical pulp mills. The technologies are evaluated with respect to net CO2 emission, oil use, primary energy use, biomass use and monetary cost. We find that BLG in chemical pulp mills is favourable compared to stand-alone production of fuels and electricity from biomass. It is more efficient to implement BLG with motor fuels production and stand-alone electricity production from biomass, than to implement BLG with electricity production and stand-alone production of motor fuels. Increased energy efficiency in refining of thermomechanical pulp gives CO2 savings more efficiently than stand-alone production of electricity from biomass. Sensitivity analysis indicates that our conclusions are robust with respect to energy and biomass prices and the choice of coal or natural gas for marginal electricity. Newsprint from thermomechanical pulp would require slightly less biomass and have lower costs than paper from chemical pulp, per metric ton (t) product, when the systems are also required to render the same oil use and CO2 emission reductions. Substituting mineral fillers for 25% of the chemical pulp changes the balance in favour of the chemical pulp paper. At an oil price of 40 US$/barrel, all studied pulp and paper mill technology improvements give unchanged or reduced monetary costs also when oil use and CO2 emissions are not balanced with stand-alone bioenergy plants. [Copyright &y& Elsevier]

Energy efficient cultivation is the major bottleneck for microalgal biomass production on a large scale and considered very difficult to attain at northern latitudes. In this study an unconventional method for industrial microalgae cultivation for bio-oil production using pulp and paper mill waste resources while harvesting only once a year was performed, mainly in order to investigate the energy efficiency of the process. Algae were cultivated for three months in 2014 in covered pond systems with access to flue gas and waste heat from the industry, and the biomass was recovered as thick sediment sludge after dewatering. The cultivation systems, designed to manage the waste resources, reached a promising photosynthetic efficiency of at most 1.1%, a net energy ratio (NER) of 0.25, and a projected year-round energy biomass yield per area 5.2 times higher than corresponding rapeseed production at the location. Thus, microalgae cultivation was, for the first time, proven energy efficient in a cold continental climate. Energy-rich indigenous communities quickly out-competed the oleaginous monocultures used for inoculation. The recovered biomass had higher heating values of 20–23 MJ kg − 1 and contained 14–19% oil dominated by C16 followed by C18 fatty acids. The cultivation season at 59°15′N, 14°18′E was projected to be efficient for 10 months and waste heat drying of the biomass is suggested for two winter months. The technique is proposed for carbon sequestering and energy storage in the form of microalgal sludge or dry matter for later conversion into biochemicals. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this study was to assess the environmental impacts of the Norwegian pulp and paper industry, considering the production of pulp fibres and printing paper. The pulp fibres included in this study are thermo-mechanical pulp and kraft pulp fibres, which differ with respect to the energy consumption and chemicals used during production. The assessed paper grades were super-calendered paper and newsprint. The study was a cradle to gate approach, and corresponds to an attributional life cycle assessment (LCA). The LCA was based on data collected from main pulp and paper producers in Norway. Importantly, aspects related to the increasing use of mineral fillers in the production of newsprints were assessed. The results showed that a reduction of more than 18% climate change impact (kg CO2 eq.) was achieved by increasing the fraction of fillers, in the newsprint furnish. Furthermore, the total climate change impact reduction depended on the applied energy mix. Assuming that the production of printing paper was based only on Norwegian energy mix, yielded a reduction of the climate change impact by more than 44% in 2011, compared to the production based on Scandinavian and European energy mix. Additionally, the input and output transport contributed to more than 20% impact in several cases. We thus concluded that the estimated environmental impacts were affected by; i) the furnish composition of a given paper quality, ii) the input and output transport and iii) the use of different primary grid energy sources. [Copyright &y& Elsevier]

Abstract: This study considers different alternative uses of secondary heat in a mechanical pulp and paper mill. The considered alternatives are (1) three different heat exchanger network retrofits, (2) drying of bark, (3) drying of primary and activated sludge and (4) drying of both bark and sludge. The data has been gathered from an operating mill and a simulation model has been built to examine the mill-wide effects of the proposed changes. Targets for steam and cooling water use, used in the heat exchanger network retrofits, have been evaluated using pinch analysis. The amount of available secondary heat found in the pinch analysis can be used in drying of bark or sludge. Sludge is typically burned together with mill fuel in the bark boiler of a power plant to deliver heat and electricity to the mill. These wood-based biofuels typically consist of 50%w.b. water, which will evaporate and consume some of the fuel''s energy content during combustion. Fuel drying is a way to increase the heating value of fuels and to increase the energy efficiency of heat and power production. The utilisation of low-temperature secondary heat in the drying may reduce the need for fuels and primary energy in the mill. The different ways of using the secondary heat have different effects on primary fuel consumption and electricity production. Therefore the different results are compared using the reduction of CO2 emissions as a common criterion. The results show that all the considered alternatives have great energy-saving potential up to 8MW steam use in winter and 6MW in summer time. [Copyright &y& Elsevier]

Abstract: Paper production is an energy-intensive process and accounted for about 9% of industrial energy demand in Germany in 2008. There have only been slow improvements in energy efficiency in the paper industry over the past twenty years. Policies can accelerate the progress made, but knowledge about the remaining efficiency potentials and their costs is a prerequisite for their success. We assess 17 process technologies to improve energy efficiency in the German pulp and paper industry up to 2035 using a techno-economic approach. These result in a saving potential of 34 TJ/a for fuels and 12 TJ/a for electricity, which equal 21% and 16% of fuel and electricity demand, respectively. The energy savings can be translated into mitigated CO2 emissions of 3 Mt. The larger part of this potential is found to be cost-effective from a firm''s perspective. The most influential technologies are heat recovery in paper mills and the use of innovative paper drying technologies. In conclusion, significant saving potentials are still available, but are limited if we assume that current paper production processes will not change radically. Further savings would be available if the system boundaries of this study were extended to e.g. include cross-cutting technologies. [Copyright &y& Elsevier]

Reducing “energy waste” has helped manufacturing companies to systematically improve their productivity. However, optimization goals related to the resource energy (energy efficiency, demand side management, integration of renewables) are still addressed in an isolated manner. Here we present a stepwise methodology on how to unite the different facets of energy usage in a factory planning process. Our results indicate that addressing the energy related planning goals in an integrated manner helps to reduce both life cycle costs and the environmental impact of factories. Future research will refine the presented planning framework and quantify the correlation between conventional and energy related planning targets. [ABSTRACT FROM AUTHOR]

Abstract: The pulp and paper industry is one of the most energy-intensive industries worldwide. In 2007, it accounted for 5% of total global industrial energy consumption and 2% of direct industrial carbon dioxide (CO2) emissions. An energy audit is a primary step toward improving energy efficiency at the facility level. This paper describes a plant-wide energy audit aimed at identifying energy conservation and CO2 mitigation opportunities at a paper mill in Guangdong province, China. We describe the energy audit methods, relevant Chinese standards, methods of calculating energy and carbon indicators, baseline energy consumption and CO2 emissions of the audited paper mill, and nine energy-efficiency improvement opportunities identified by the audit. For each of the nine options, we evaluate the energy conservation and associated CO2 mitigation potential. The total technical energy conservation potential for these nine opportunities is 967.8terajoules (TJ), and the total CO2 mitigation potential is equal to 93,453tonnes CO2 annually, representing 14.4% and 14.7%, respectively, of the mill’s total energy consumption and CO2 emissions during the audit period. [Copyright &y& Elsevier]

The pulp and paper industry faces several challenges linked to climate and environmental impact, resource efficiency, rising energy prices, increased competition for biomass resources, and declining demand for traditional printed paper products. However, these challenges also offer strategic opportunities for the industry to develop into a competitive, resource-efficient, and low-carbon industry in line with a biobased economy. Against this background, this paper aims to analyse current energy strategies in the pulp and paper industry in Sweden. Specifically, the paper analyses how companies combine continuous process efficiency to reduce energy costs with activities that could be developed into new energy-related products to increase revenue. Most of the analysed companies work to various degrees with both these strategies, employing methods that include improving energy efficiency, energy security, and energy conversion, as well as developing a wide range of biobased energy products. However, our study indicates that there is an untapped potential associated with energy product development, and we conclude that energy efficiency measures can free up resources, enabling the development of new energy products. Finally, several potential managerial outcomes and implications are outlined. • The paper analyses the energy strategies in the pulp and paper industry in Sweden. • Energy strategies focus both to improve energy efficiency and develop new energy-products. • The companies' energy strategies combined exploitation and exploration. • A number of managerial implications are presented. [ABSTRACT FROM AUTHOR]

Small area femtocell increases the energy efficiency of the cellular network as the distance between base station and user is very less. Mobile femtocell causes the spectrum reuse to be used at very large extent making spectral efficiency suffer. This paper discusses recently researched techniques that have been used to increase the spectral efficiency in mobile femtocell network. But these techniques also come with their own limitations. Considering this, data aggregation and compression technique can be consider as one of the best contender to increase the spectral efficiency in cellular network which is also been explained in this paper. [ABSTRACT FROM AUTHOR]

The advancement in plastic and plastic based products in last two decades has imposed a serious threat to the environment. This has led to an increase in the demand for sustainable and biobased products. Paper and paper products are good alternatives to their plastic counterparts. A key element of paper industry is the raw material (wood, bamboo and nonwood agricultural residues such as bagasse, straws etc.) from which pulp is produced. The pulp is then utilized for production of paper. There are many pulping processes to prepare pulp of various qualities. For fine grade pulp, chemical pulping is used. The chemical pulp is produced by soda, kraft and sulphite pulping processes. However, for newsprint grade pulp, stone ground wood (SW), thermomechanical (TMP), chemi-thermomechanical (CTMP), chemi-mechanical (CMP) or refiner mechanical (RMP) corresponding pulping processes are employed. The method of pulp preparation (pulping process) consumes large amount of energy and chemicals. A new pulping process with electron irradiation using biowaste (bagasse) as a raw material is discussed in this work. Bagasse pulping process is found to reduce about 50% of energy consumption during pulping process. The process is referred to as 'ECTMP' (Energy Efficient Chemi-Thermo Mechanical Pulping). The paper produced from aforesaid method also reflected no loss of strength properties with respect of TMP reference pulps. Henceforth, preliminary calculation based on experimental results shows that the proposed bagasse ECTMP process explored the scope of energy savings of the order of 50%. • Energy efficient thermochemical process for biowaste conversion into paper was explored. • The effects of high energy electron irradiation pre-treatment were investigated. • Chemical pretreatment improved the strength properties of paper. • Specific energy consumption of bagasse pulping was significantly reduced. • The approach of pre-irradiation can be implemented for other raw materials also. [ABSTRACT FROM AUTHOR]

Abstract: In this study the possibilities of making a cost-effective heat exchanger retrofit in a simulated thermo mechanical pulp and paper mill are analysed using advanced composite curves. The use of advanced composite curves is a fairly new method developed in Chalmers University, and they have not previously been used to analyse a mechanical pulp and paper mill. The simulated mill used as an example in this study has one TMP (thermo mechanical pulping) line, one paper machine, debarking and auxiliary systems. The results show that the advanced curves give valuable information on the system and provide guidance as to where to look for improvement potential. The relative costs of different improvements are in line with traditional knowledge of improvement costs. [Copyright &y& Elsevier]

This paper presents a comparison between four gasification-based biorefineries integrated with a pulp and paper mill. It is a continuation of 'Transportation fuel production from gasified biomass integrated with a pulp and paper mill - Part A: Heat integration and system performance'. Synthesis into methanol, Fischer-Tropsch crude or synthetic natural gas, or electricity generation in a gas turbine combined cycle, were evaluated. The concepts were assessed in terms of GHG (greenhouse gas) emissions and economic performance. Net annual profits were positive for all biofuel cases for an annuity factor of 0.1 in the year 2030; however, the results are sensitive to biofuel selling prices and CO 2,eq charge. Additionally, GHG emissions from grid electricity are highly influential on the results since all biofuel processes require external power. Credits for stored CO 2 might be necessary for processes to be competitive, i.e. storage of separated CO 2 from the syngas conditioning has an important role to play. Without CO 2 storage, the gas turbine case is better than, or equal to, biofuels regarding GHG emissions. Efficiency measures at the host mill prior to heat integration of a gasification process are beneficial from the perspective of GHG emissions, while having a negative impact on the economy. [ABSTRACT FROM AUTHOR]

Abstract: The Scandinavian mechanical pulp and paper industry has been facing great challenges during the past decades, mainly because of declining demand for newsprint, and higher prices on raw material and energy. One way of increasing profitability is to produce more value-added products besides the production of pulp and paper. In this study, integration potentials of three possible future biomass gasification-based energy mills with an existing thermo-mechanical pulp (TMP) mill, co-located with a sawmill, have been evaluated. The product gas was utilized for electricity production in a gas turbine, for production of methanol or for production of Fischer–Tropsch (FT) liquids. Integration of the energy mills showed good potential as the TMP mill constitutes a heat sink for which the excess heat from the energy mills can be utilized all year round. However, since there is little excess heat from the TMP mill at the required level to be utilized for biomass drying, for example, heat integration is typically one way. It has also been shown that integration of biomass gasification with a TMP mill results in larger CO2 emissions reduction than stand-alone operation. Still, compared to co-firing biomass in a coal power plant, the energy mills all have lower potentials for CO2 emissions reduction. [Copyright &y& Elsevier]

Abstract: Integration of biomass gasification with a pulp and paper mill is a possible route to create more value-added products. This route facilitates, for example, more advanced electricity generation and production of biomass based transportation fuels or chemical feedstock. Each unit operation in such a process affects overall efficiency as well as possibilities for process integration. In this paper, the impact of different dryer types in a biomass gasification combined cycle (BIGCC) has been evaluated in terms of efficiency and economic performance. The BIGCC was sized so that the excess heat would replace the current steam production from bark and oil. The results show that the dryer type can have a significant impact on economic performance and efficiencies. A BIGCC with an integrated belt dryer, utilizing excess heat to heat the drying air from the mill, can result in electrical efficiencies of up to around 40%, while e.g. a steam dryer can reach 36–37%. Choice of oxidant, air or oxygen, in the gasifier affects both capital and operational cost. Air was proven to be the most cost efficient solution for the cases evaluated in this study. The investment of around 100 to 140 million Euros for a BIGCC facility is profitable for most evaluated cases for an annuity factor of 0.1, while the net annual profit is negative for most cases when the annuity factor was increased to 0.2, even when including financial support for renewable electricity. [Copyright &y& Elsevier]

Abstract: Adoption of energy efficient technologies is considered a key sustainability strategy for reducing greenhouse gas emissions in global industries. This article aims to assess costs of energy savings and carbon reduction from applying energy efficiency technologies in the US pulp and paper sector. Applicable efficiency measures were identified and their cost effectiveness was evaluated in two historical years – 1994 and 2006. Potential savings of final energy use resulting from applicable sustainability options were estimated as 707 PJ in 1994 and 1064 PJ in 2006, respectively, corresponding to approximately 32% of the sector''s annual final energy use in 1994 and 62% in 2006. The associated carbon-emission reduction was 8.1 million ton of carbon (MtC) in 1994 and 11.8MtC in 2006, corresponding to 26% and 45% of sector''s total energy-related carbon emissions in 1994 and 2006, respectively. Using the concepts of cost of conserved energy and cost of carbon reduction, we estimated that cost effective sustainability options contributed to final energy savings in the range of 15–25% of the annual energy use, and carbon-emission reduction from 14% to 20% of annual carbon emissions from the sector. [Copyright &y& Elsevier]

Abstract: The paper industry is, with about 6% of the total worldwide industrial energy use, an energy-intensive industry. The drying section is with approximately 50% the largest energy consumer in a paper mill, energy use in this section is mainly heat use. Several options to decrease heat use in conventional multi-cylinder drying sections are investigated, calculating the effect on energy use. Optimization measures include a) decreasing the amount of water evaporation by applying additives in higher consistencies and by lowering the water viscosity, b) decreasing the heat use of water evaporation by increasing the dew point temperature of the dryer and c) increasing the amount of heat recovery by using exhaust air to not only pre-heat the incoming air but also to increase process water temperatures. These could all be achieved by retrofitting and/or choosing different processing conditions in existing factories. The combined thermal heat saving potential due to the optimization actions is 1.3GJh/t paper (or 32% of the drying section’s heat use) as compared to the reference situation. [ABSTRACT FROM AUTHOR]

Abstract: The success of any process improvement study depends on the quality of the available data and the way in which the plant-specific characteristics are incorporated in the applied conceptual models; in the context of process integration studies these issues are directly related to the rules followed during the data extraction stage. Improving energy efficiency in a pulp and paper Kraft mill requires the identification of the most promising heat recovery network retrofit projects. In a retrofit analysis using pinch technology/process integration methods, only the process streams associated to the existing heat exchangers and some outlet streams (such as wastewater/effluent streams and vents) with high potential for heat recovery are usually included, while the energy exchanged through non-isothermal stream mixing (NIM) or direct heat transfer (DHT) is often assumed fixed and is not considered in the analysis. Relaxing this assumption requires extracting more data to represent the DHT design configuration that exists in the plant. However, different data extraction options can be considered to represent the DHT configuration depending on the associated process/operation constraints. This work describes a systematic procedure to extract and analyse the impacts of DHT on the overall energy efficiency of a Kraft process with a specific focus on mixing along the pulp line and in water tanks. [Copyright &y& Elsevier]

To reduce energy use and achieve a low carbon production in pulp and paper industry (PPI), it is essential to improve energy efficiency in pulp and paper production. In this study, the energy savings from the PPI were estimated based on a techno-economic analysis by EAGER tool for PPI at the factory level. The structure and implement procedure were introduced initially. Two typical pulp and paper mills from China were determined to estimate the impact of selected energy efficiency technologies (EETs) on energy savings as the cases in the base year. One Factory (A) only produced paper products (i.e. corrugated paper and Kraft linerboard) while the other Factory (B) also produced market pulp besides sack paper. In totally 22 selected EETs were applied to assess their saving potential in Factory A, and 29 measures were applied in Factory B. The results show that 2290 TJ and 1179 TJ of final energy could be saved annually in Factory A and B, corresponding to reduction of 29.4% and 13.6% total energy consumption respectively for the case factories. The CO 2 reduction potential was 32.3% for Factory A compared with that of 16.6% in Factory B. It suggests that the pulp and paper mills should encouraged to use this method estimating energy saving potential, and improve their energy efficiency with suggested measures in order to reduce energy consumption and related carbon emissions further in the coming years. • Energy savings of pulp and paper production were estimated at the factory level. • A techno-economic evaluation tool was applied to access the energy savings and carbon emission reductions. • Two typical pulp and paper factories from China were investigated to estimate their energy savings in the base year. • It is useful to assess energy savings and select feasible EETs in achieving energy saving and emission reduction targets. [ABSTRACT FROM AUTHOR]

Under the dual pressure of energy consumption and environmental pollution, mankind hopes to develop clean and renewable alternative energy, and the rapid development of fuel cells meets people's demand for energy-efficient power systems. The emergence of portable micro energy systems represented by microfluidic fuel cells, such as paper-based microfluidic fuel cells, has greatly enriched the means of medical detection to better cope with the threat of disease transmission. In this work, the numerical simulation method is innovatively introduced to study the paper-based microfluidic fuel cells. Both transient and steady-state modes are employed to demonstrate the whole operation process of the paper-based microfluidic fuel cell. In addition, the different structural parameters, including electrode spacing, the distance between electrode and inlet, channel thickness, and electrode length, are also investigated their influence mechanisms on cell performance. Results show that the increase of most structural parameters decreases cell output power in different degrees. Even on the premise that increasing channel thickness has a positive impact on the output power, the fuel utilization still shows a downward trend. These conclusions provide theoretical support and reference for future optimization work and accelerate the development of microfluidic fuel cells. • Numerical simulation is employed to study paper-based microfluidic fuel cell. • The effects of structure parameters on cell performance are discussed. • Through fuel concentration distribution to reveal cell performance mechanism. • Fuel utilization is used to evaluate energy efficiency. [ABSTRACT FROM AUTHOR]

The pulp and paper industry is one of the five most energy-intensive industries world-wide. In Sweden, most pulp and paper mills were certified with a standardized energy management system already in 2005. As Swedish mills have more than a decade of experience with energy management systems and energy key performance indicators (KPIs), studying KPIs within Swedish pulp and paper mills will enable both a state-of-the-art positioning of best-practice in relation to energy KPIs in pulp and paper mills, but also spot potential barriers and drivers in the utilization of energy KPIs. This paper studies the current level of implementation and operationalization of energy-related KPIs in the Swedish pulp and paper industry. The results show a potential for improvement. • Pulp and paper mills' level of implementation of energy-related KPIs is studied. • 25% of the mills apply best practice regarding the establishment of energy KPIs. • Pulp and paper mills can potentially improve their monitoring of energy KPIs. • Lack of resources is a major barrier to implementing relevant energy KPIs. [ABSTRACT FROM AUTHOR]

Regular Ship hull maintenance is an essential for sustainability. The maintenance work of ship hulls that involve human labor suffers from many shortcomings. Maintenance robots have been introduced for drydocks to eliminate these shortcomings. An energy-efficient Complete Coverage Path Planning (CCPP) is a crucial requirement from a ship hull maintenance robot. This paper proposes a novel energy-efficient CCPP method based on Glasius Bioinspired Neural Network (GBNN) for a ship hull inspection robot. The proposed method accounts for a comprehensive energy model for path planning. This energy model reflects the energy usage of a ship hull maintenance robot due to changes in direction, distance, and vertical position. Furthermore, the proposed method is effective for dynamic workspaces since it performs online path planning. These are the major contributions made to state of the art by the work proposed in this paper. The behavior and the performance of the proposed method have been compared against state of the art through simulations considering Hornbill, a multipurpose ship hull maintenance robot. The validation confirms the ability of the proposed in realizing a complete coverage of a given dynamic workspace. According to the statistical outcomes of the comparison, the performance of the proposed method significantly surpasses that of the state-of-the-art methods in terms of energy usage. Therefore, the proposed method contributes to the development of energy-efficient CCPP methods for a ship hull maintenance robot. • A novel coverage method based on Glasius Bioinspired Neural Network is proposed. • The proposed method is intended for a multipurpose ship hull maintenance robot. • A comprehensive energy model is utilized by the proposed method for path planning. • The proposed method is significantly efficient than the state of the art methods. • The paper contributes to the development of a ship hull maintenance robot. [ABSTRACT FROM AUTHOR]

Water removal during paper manufacturing is of primary importance to production rate and cost efficiency for the pulp and paper industry. It is crucial to develop methods to reduce energy consumption by increasing the percent solids in the paper web entering the dryers from the presses. This research aimed to develop a fundamental understanding of the effect of bio-chemo-mechanical pretreatments on a bleached softwood fiber matrix and evaluate the impact on the percent solids of the paper web after pressing. Experiments included enzymatic, refining, and cationic polymer pretreatments on the bleached softwood pulps, followed by laboratory papermaking and determining the equilibrium moisture content (EMC) after pressing and the pulp and paper properties. The combined effect of mild refining, controlled enzymatic pretreatments, and cationic strength aids proved to enhance the water removal during wet pressing (up to 35 % reduction) and increase paper strength (up to 60 % increase). The results of increased solids after pressing were used to calculate the potential reduction in drying energy during paper manufacturing. Energy savings of around 10 % for paper drying could be achieved through fiber matrix modification by bio-chemo-mechanical pretreatment. Enzymatic pretreatments have previously been conventionally applied before refining as an energy-saving method. However, this research shows that synergistic actions of enzymes added after refining modify the fibers and create the optimal conditions for enhancement in drainage, press dewatering, and paper properties. [Display omitted] • Enzyme-assisted fiber modifications improve press dewatering and paper strength. • Enzyme blends can enhance fiber cell wall flexibility and fibrillation. • Synergistically, enzymes increased ∼35% press dewatering and ∼60% tensile strength. • Enzymes, mild refining, and cationic biopolymers enhance paper process efficiency. • This research introduces alternative methods for decarbonizing the paper industry. [ABSTRACT FROM AUTHOR]

This review offers an extensive examination of the evolving landscape of Long Range (LoRa) Microstrip Patch Antennas (MPAs), highlighting their crucial role in optimizing LoRa systems within the Internet of Things (IoT). As the demand for energy-efficient standards like LoRa grows with the expanding IoT market, this research becomes increasingly relevant. This comprehensive review, the first of its kind, serves as a foundational resource for researchers seeking to optimize LoRa systems within the IoT. The study has categorized these LoRa MPAs – including monopole, Planar Inverted F Antenna (PIFA), dipole, yagi-uda, and array – into single band, dual-band, multiband, and wearable antennas, thus providing substantial viewpoints on their diverse design architectures and performance characteristics. Through systematic tabulation, the review facilitates a thorough comparison of antenna advancements. Notably, the review addresses inherent challenges in LoRa MPAs, emphasizing critical aspects that necessitate attention, including the need for miniaturization and integration, advancements in substrate materials and fabrication techniques, and the imperative for reconfigurable and adaptive antennas. Various approaches to enhance antenna performance are explored, including the metamaterial incorporation, slot-based enhancements, Electromagnetic Band Gap (EBG), dielectric resonator antennas (DRAs), substrate material considerations, and corrugation techniques. Looking ahead, the paper explores the future trends and subtle considerations that are poised to shape the trajectory of LoRa MPAs. To the best of our knowledge, this paper represents the first comprehensive review on the multifaceted topic of LoRa MPAs, serving as a foundational resource for researchers in the field. [ABSTRACT FROM AUTHOR]

This paper examines the pervasive barriers hindering the widespread adoption of energy efficiency measures across various sectors. It categorizes these barriers into economic barriers, high upfront costs, organizational challenges, such as technical expertise and behavioral barriers, namely risk aversion and framing. To address these barriers, a comprehensive review of energy efficiency policies is conducted. These policies include incentives, coercive instruments, award systems, university industry collaboration, and technical support. To review energy efficiency barriers and policies, a methodological approach integrating non-structured snowball sampling with targeted literature review techniques was devised. Finally, the paper underlines that the success of these policies is contingent upon the active involvement, the collaboration, and the feedback of businesses, ensuring the feasibility of these policies. Their proactive engagement is indispensable in tackling energy efficiency barriers and driving the implementation of energy-efficient technologies, thus paving the way for a more sustainable and competitive businesses. [ABSTRACT FROM AUTHOR]

This paper examines the role of energy efficiency in enhancing corporate sustainability and competitiveness. Employing a systematic literature review methodology, we analyze the financial advantages, corporate sustainability alignment, and crisis resilience associated with energy efficiency measures in business operations. The results highlight the significant cost savings, improved profitability, and enhanced competitiveness resulting from energy-efficient practices. Furthermore, we elucidate how energy efficiency initiatives align with broader corporate sustainability objectives, reduce environmental impact, and promote corporate social responsibility. Additionally, the paper discusses how energy efficiency enhances organizational resilience by bolstering preparedness for crises and promoting long-term sustainability and adaptability. The main implications of our findings underscore the importance of prioritizing energy efficiency as a strategic imperative for businesses seeking to achieve sustainability goals while maintaining competitiveness in a rapidly evolving global landscape. [ABSTRACT FROM AUTHOR]

Aerogels, with their exceptional properties such as high insulation performance, lightness, and eco-friendliness, present immense potential for use in the construction industry. This paper reviews the progress in research and application of various types of aerogels in construction, highlighting notable case studies demonstrating energy efficiency gains and sustainability impacts. It delves into the lifecycle of aerogels, discussing environmental implications at each stage. Despite their potential, aerogels face certain limitations including production complexity, brittleness, and high cost which hinder their widespread adoption. The paper further discusses these challenges and highlights the need for continuous research and development efforts to overcome them, with a view to achieving more scalable production, enhanced mechanical properties, and cost reduction. Looking forward, the paper discusses the expansive horizon of aerogel research, emphasizing the potential of smart aerogels, their integration with renewable energy systems, and exploring the possibility of recycling or creating bio-based aerogels to enhance their overall sustainability. While still in early stages, aerogels promise to be a major contributor to the future of construction, leading to more sustainable and efficient built environments. [ABSTRACT FROM AUTHOR]

The adhesion of gases to the electrodes is a major reason for reductions in energy efficiency, and hinders the production of hydrogen in alkaline water electrolysis (AWE). The development of an effective solution to this problem will be crucial for the design and optimization of AWE. In this paper, we present a novel structure for an electrolyser in which baffles are inserted into the channel. The flow process of the electrolyte and the electrochemical reactions in the electrolyser with the new structure are simulated, and the effects of the added baffles on the distribution of the gas phase production and the efficiency of energy conversion are analysed. Several important structural parameters are considered, such as the angle, number and length of the baffles, and corresponding numerical calculations are performed. In order to carry out a comprehensive evaluation of the performance of each electrolyser, the energy efficiency of AWE is evaluated and the current effect, ohmic overvoltage effect and bubble overvoltage effect caused by gas adhesion are quantitatively investigated. The results show that the flow of the electrolyte can be divided into three phases when baffles are added to the channel of the electrolyser, and that the baffles play a crucial role in both the transition phase and the full development phase. The maximum reduction in gas coverage at the electrodes reaches 60% and the maximum increase in energy efficiency reaches more than 3.0% with the addition of baffles. The addition of baffles has significant effects on the current and ohmic overpotential, and the balance between the gas coverage and ohmic overpotential can allow the maximum energy efficiency of the AWE to be achieved. [Display omitted] • A novel design for an electrolyser with baffles optimises the electrolyte flow. • The mechanism of transport in an electrolyser with baffles is analysed. • The effects of the angle, number and location of baffles are studied. • The thermodynamics performance of electrolyser is evaluated. [ABSTRACT FROM AUTHOR]

• An enhanced ejector-subcooler CO 2 transcritical refrigeration cycle is presented. • A parametric analysis and optimization of the enhanced cycle and the baseline cycle are carried out. • The results suggest the integration of the proposed cycle could achieve more compact and reliable systems. • The maximum COP improvements are computed as 11.7%-17.5% when the gas cooler outlet temperature ranges from 35 °C to 50 °C and the evaporating temperature is -40 °C. The main drawback associated with CO 2 refrigeration systems is related to their performance reduction during transcritical operation at warm climate conditions, which may be compensated by better cycle architectures such as the split-cycle with subcooling or the flash-tank configuration, among others. Specifically, the use of standard gas-ejectors together with parallel compressors provides even better efficiency improvements, not being able to use them with low-temperature evaporators to prevent the triple point inside the ejector. This paper proposes an enhanced cycle with a gas ejector for two-stage compressor architectures with vapor injection from the flash-tank, which is able to operate at low evaporating temperatures and that provides a greater performance improvement the more severe the climate conditions are. The methodology conducted is based on a thermodynamic analysis that includes parametric evaluation and cycle optimization, comparing the results to a conventional CO 2 transcritical cycle with flash-tank and dynamic vapor injection architecture. The main results show that a maximum Coefficient of Performance improvement of 17.5% is achievable for transcritical operation at -40 °C evaporating temperature. The compressor displacement capacity required with the enhanced cycle is up to 9% lower for the same refrigeration demand, reducing the electrical consumption as well as the compressor expenditure. Moreover, greater vapor injection mass flow rates are obtained by the gas-ejector injection with discharge temperature reductions up to 18%, enhancing the system reliability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Impact of big data and green loans on firm's energy efficiency is analyzed. • Information and transaction costs are paths for big data affecting green loan choices. • Changes in firm's decisions due to improved energy efficiency are discussed. Green digital finance is an instrumental way to promote technological innovation, accelerate the low-carbon transition, and foster sustainable development. With the emergence of green digital finance, how does it affect firms' energy use efficiency? Using big data and green loans as an entry point, the impact of green digital finance on corporate energy efficiency and the role of big data are examined. We provided a simple theoretical model to analyze the green loaning behavior of the banking sector after applying big data and its impact on corporate energy efficiency. Our research finds that: (1) The application of big data can make it easier for the banking sector to obtain loan companies' information and reduce loan delinquency rates. This will reduce the information and transaction costs of the banking sector and expand the scale of optimal green loans. (2) The optimal green loan scale has a negative relationship with the optimal green loan interest rate. (3) The application of green loans by firms can improve energy efficiency and have a range of impacts on firms' decision-making, including an increase in the emission reduction ratio, innovation probability, output, and profit, followed by a decrease in energy consumption and pollution emissions. This paper further clarifies the channels through which green digital finance affects energy efficiency and specifies the role of big data in green digital finance. This could help relevant policymakers design more effective green digital finance policies, contributing to carbon peaking and carbon neutrality goals. [ABSTRACT FROM AUTHOR]

Abstract: 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. [Copyright &y& Elsevier]

Black liquor (BL) is a by-product in the paper and pulp industry. Although it has good potential for providing energy as an industrial waste, BL's high moisture content limits its usability. In this study, an integrated system to effectively co-produce power and ammonia (NH 3) from BL is modeled and evaluated. The modeling and integration are conducted using the principles of exergy recovery and process integration to effectively circulate the energy/heat throughout the whole system. The developed system involves BL evaporation, gasification, syngas chemical looping (SCL), and NH 3 synthesis. During SCL process, H 2 , CO 2 , and N 2 -rich gas are produced consecutively in the oxidation, reduction, and combustion reactors, respectively. The designed system can achieve the total energy efficiency of ~50%. The result also suggests that N 2 -rich gas and pure H 2 produced during SCL can be used directly for NH 3 synthesis without any additional energy penalty. The additional step for CO 2 separation can also be avoided, affording a cleaner and more efficient system that provides complete carbon capture. • An efficient energy system of a H 2 production is proposed. • The system comprises evaporation, gasification, syngas chemical looping and NH 3 synthesis. • High energy efficiency in NH 3 production can be realized. • The designed system achieved about 50% of total energy efficiency. • The system has cleaner and more efficient system with 100% carbon capture. [ABSTRACT FROM AUTHOR]

The paper describes a new method for determining the energy efficiency of the life cycles of wind farms by the aggregated data of energy costs. The rationale for the use of aggregated data to determine energy costs during the life cycle of the wind farms is given. The classification of wind turbines and wind farms elements by the parameters and technical characteristics of the elements with subsequent division into groups for which aggregated data of energy costs are determined is given. Within the framework of the method have been developed an algorithm for determining energy costs on the production of elements of wind turbines and wind farms and formulas for their calculation during the life cycle of wind farms. In order to test the method, energy cost was calculated during the life cycle for two wind farms with wind turbines that differ parameters and technical characteristics of the elements and their energy efficiency was determined. It has been shown that the use of a hydrogen storage unit as part of a wind turbine makes it possible to efficiently use energy during down periods and increase the efficiency of the installation by 25–30%. It is noteworthy that a wind-hydrogen farm allows not only to accumulate excess energy during lean periods, but also to save the resource of wind turbines. When the energy reserve in the hydrogen battery reaches close to full, part of the wind turbines of the wind-hydrogen farm can be automatically temporarily stopped in a given order. This technology can provide an extension of the warranty service life for each wind turbine. [ABSTRACT FROM AUTHOR]

Two-step thermochemical cycle (TSTC) is a promising approach for solar-driven H 2 O splitting. However, extremely high reduction temperature (T red) is a key challenge limiting the development of TSTC. Two-step electro-thermochemical cycle (TSEC) has recently emerged to overcome this problem. However, the pros and cons of TSEC and TSTC are under debate. In this paper, a thermodynamic model was developed for studying the thermodynamic fundamentals and the variation rules of energy efficiency of TSEC and TSTC. The thermodynamic mechanisms of TSTC and TSEC were compared using the Gibbs free energy method and the Exergy & energy level analysis method. In comparison to TSTC, TSEC tends to operate at a lower T red , enabling isothermal operation at moderate temperatures (<1473 K) while sustaining a high H 2 O conversion rate. In addition, energy efficiency analysis reveals that the introduction of 0.2 V auxiliary voltage can increase the energy efficiency from 0.25 in TSTC to 0.38 in TSEC, showing the advantage of TSEC for H 2 O splitting in terms of energy efficiency. This study analyses the advantages and disadvantages of TSTC and TSEC for H 2 O splitting, demonstrating a reference for further development of solar-driven H 2 O splitting. • The thermodynamic mechanisms of TSTC and TSEC are compared. • TSEC tends to operate at a lower reduction temperature with a high H 2 O conversion rate. • A thermodynamic model is developed for studying the energy efficiency of TSEC for H 2 O splitting. • 0.2 V auxiliary voltage can increase the energy efficiency from 0.25 to 0.38. [ABSTRACT FROM AUTHOR]

The measures needed to limit global warming pose a particular challenge to current fossil fuel exporters, who must not only decarbonise their local energy systems, but also compensate for the expected decline in fossil fuel revenues. One possibility is seen in the export of green hydrogen. Using Algeria as a case study, this paper analyses how different levels of ambition in hydrogen exports, energy efficiency and fuel switching affect the cost-optimal expansion of the power sector for a given overall emissions reduction path. Despite falling costs for photovoltaics and wind turbines, the results indicate that in countries with very low natural gas prices, such as Algeria, a fully renewable electricity system by 2050 is unlikely without appropriate policy measures. The expansion of renewable energy should therefore start early, given the high annual growth rates required, which will be reinforced by additional green hydrogen exports. In parallel, energy efficiency is a key factor as it directly mitigates CO2 emissions from fossil fuels and reduces domestic electricity demand, which could instead be used for hydrogen production. Integrating electrolysers into the power system could potentially help to reduce specific costs through load shifting. Overall, it seems advisable to analyse hydrogen exports together with local decarbonisation in order to better understand their interactions and to reduce emissions as efficiently as possible. These results and the methodology could be transferred to other countries that want to become green hydrogen exporters in the future and are therefore a useful addition for researchers and policy makers. • The required strong capacity expansion for PV and wind is challenging, but feasible. • "Energy efficiency first" benefits both the local energy transition and H2 exports. • Fully renewable power systems require a suitable political framework. • Higher hydrogen exports might help to reduce the specific power system cost. • Fossil capacity expansion must be stopped to avoid lock-ins and higher future costs. [ABSTRACT FROM AUTHOR]

To cope with the severe challenges related to traditional economic-centered urbanization, the Chinese government has proposed a people-oriented new-type urbanization strategy, which focuses on promoting the coordination and sustainable development of the environment, economy, and society. The existing literature has studied the impact of traditional urbanization on energy use but has not yet revealed the mechanisms and effects of the new transformation of urbanization on energy efficiency. Based on socio-economic-natural complex ecosystem theory, this paper systematically explains how new-type urbanization affects energy efficiency. By adopting a newly developed dynamic panel threshold model, the paper examines the complex impact of new-type urbanization on energy efficiency using panel data of 285 cities in China from 2003 to 2017. The results show that new-type urbanization has a significant double-threshold effect on energy efficiency. As the new-type urbanization level increases, the improvement effect of new-type urbanization on energy efficiency presents the change features of "strong-weakened-stronger." The heterogeneity analysis shows that under the constraints of multiple factors, such as new-type urbanization stages, geographic regions, economic development levels, and resource endowment, the impact of new-type urbanization on energy efficiency varies significantly. Targeted and differentiated policy recommendations for promoting new-type urbanization and energy efficiency are proposed. [ABSTRACT FROM AUTHOR]

Deinking of recycled pulps is an important operation intended to provide pulps appropriate for making paper and paperboard products from recycled wastepaper. Conventionally, deinking of recycled pulp is conducted in a flotation cell equipped with an agitator. We have investigated the applicability of a new flotation cell based on a column without an agitator present to accomplish the deinking of typical wastepaper feedstocks and also a feedstock consisting of rejects from a conventional deinking cell. Experimental results on the deinking operation indicate that it is possible to achieve deinking of a mixture of photocopier and laserprinted paper in the column flotation cell. The performance of the column, as measured by the resultant pulp's brightness and ink particle size distributions, is comparable to that of a conventional laboratory cell which incorporates severe agitation regimens. Thus, it is found that the agitator can be eliminated by using the column flotation design which could yield significant electrical energy savings in addition to savings in capital costs and other operational and maintenance costs. A series of deinking experiments were also performed on a feedstock consisting of rejected waste obtained from a conventional cell in a pilot plant. We found that deinking of the rejected waste could yield significant usable fiber. This indicatesthe potential of the column flotation technique in enhancing the reuse of a waste component thus reducing the volume of deinking waste rejected into the environment. [ABSTRACT FROM AUTHOR]

• A bibliometric analysis of the relevant literature on tunnel lighting was conducted. • The literature is sorted by energy saving, visual comfort, and low carbon. • The relationship between energy saving and low carbon is discussed. • The relationship between energy saving and comfort is also discussed. • The optimization methods of tunnel light environment are summarized. A reasonable and applicative tunnel light environment is important to ensure driving safety. This review aims to contribute to this growing area of research by exploring the tunnel lighting, which expands from safety to visual comfort, energy saving, and low carbon This paper employs bibliometric method to a visual analysis of the relevant literature and summarizes current research efforts and development directions. Firstly, the literature is visually presented by CiteSpace to elaborate the state-of-art with the dimensions of the timeline graph, the keyword co-occurrence graph, and the institutions & countries co-occurrence graph. Afterwards the literature is reviewed from three major perspectives: energy saving, visual comfort, and low carbon. Current research is mainly on luminaire arrangement, auxiliary lighting and other measures to reduce energy consumption. Visual comfort is mainly improved by optimizing the light environment's physical quantities, e.g. luminance, color temperature, color rendering etc. Current measures to achieve low carbon targets include green energy, green photoconductivity, green luminaires and green operation. Energy saving, visual comfort and low carbon are interrelated and complementary. However, a systematic understanding of how tunnel lighting contributes to carbon emission is still lacking. There is still room for development in tunnel lighting to achieve full intelligent control and the goal of carbon neutrality. [ABSTRACT FROM AUTHOR]

Waste heat is one of the major problems associated with the energy system. This paper discusses an energy, exergy, and emissions approach for the hybrid system by utilizing waste heat to the maximum extent. A thermoelectric generator (TEG) is incorporated to utilize the low-temperature waste heat from a hybrid model of a solid oxide fuel cell (SOFC) and a combined heat and power (CHP) system. SOFC is an electrochemical cell that generates power at high temperatures through an electrochemical reaction. The high-temperature, unutilized fuel leaves the SOFC, which is burned in the afterburner. The afterburner temperature controls the operating temperature of SOFC. Here, three recuperators are used to utilize this high-temperature waste heat to improve the performance of SOFC and simultaneously generate heat power from the water or gas recuperator. TEG is an auxiliary power production technology that converts waste heat into energy. A novel integration of TEG with SOFC–CHP hybrid system to utilize the low temperature waste heat, is employed. The main goal of this study is to analyze a novel SOFC–CHP-TEG hybrid system in terms of its thermodynamics and emissions. A Two stage TEG is integrated with the SOFC–CHP hybrid system. The simulation model of high temperature fuel cell (SOFC) is developed on MATLAB and validated with published results. This study analyses the impact of pressure ratio and afterburner temperature on the performance of SOFC–CHP-TEG. To do this, perform energy and exergy assessments using the principles of the first and second laws of thermodynamics. A novel exergy-based sustainability index with emissions analysis for the proposed SOFC–CHP is presented. The achieved overall energy efficiency is 62.54% at a pressure ratio of 12 and an afterburner temperature of 1000 K. With an increase in pressure ratio and temperature, the level of CO emissions reduces significantly. [Display omitted] • A novel energy exergy for SOFC–CHP-TEG system is presented. • Exergy based performance is compared and achieve 56.62. • Utilization of waste heat via TEG. • Energy efficiency of SOFC–CHP-TEG is 62.54% at rp = 12 and afterburner temperature of 900 K. [ABSTRACT FROM AUTHOR]

From both economic as well as environmental perspective energy demand is of strong and even more increasing relevance for manufacturing nowadays. But typically energy demand and manufacturing system performance (e.g. output, time demands, quality) are considered separately while actually being inherently connected in technical systems. Against this background, the paper presents a data-based approach to analyze and model those important aspects and interdependencies in an integrated manner. The developed theoretical framework and defined methodology enable deeper understanding of energy related impacts of operative influencing factors and eventually to derive fields of action for improvement. The approach was exemplary applied in an industrial case study. Results underline the feasibility, applicability, and potential benefits of the approach. [ABSTRACT FROM AUTHOR]

The relevance of digital solutions to enable sustainable value creation, the monitoring and ultimately the reduction of the environmental footprint has increased. New information technologies and increased data availability along a product's lifecycle offer more tools to assess product sustainability than ever before. This paper presents how a Digital Twin needs to be designed to help monitor product-level energy efficiency and how such a Digital Twin can be implemented. State-of-the-art research on Digital Twins and their development, lifecycle assessment, and energy efficiency are introduced. There is a lack of evaluated implementations of methodical DT development in different scenarios, especially for the evaluation of product-level energy efficiency during production. Results of a research project with the focus on the development and implementation of Digital Twins are presented. The use case is set within the scenario of the sequential development of a product simultaneously with the development of the Digital Twin. The focus is put on the implementation of an energy consumption prediction and product carbon footprint analytics module as part of the Digital Twin. The development approach is presented and recommendations for the development of future Digital Twins are derived. [ABSTRACT FROM AUTHOR]