Search

The pulp and paper industry utilizes more biomass for stationary heat and power than any other industry in the United States. In total, pulp and paper mills in the US emit ∼150 million metric tons of CO2 each year, of which 77% is biogenic. Thus, the pulp and paper industry has significant potential to indirectly remove atmospheric CO2 through bioenergy with CO2 capture and storage (BECCS). In addition, avenues for CO2 utilization exist in pulp and paper processing. Here, we analyze the technical and economic potential of integrating carbon capture, utilization, and sequestration (CCUS) technologies at pulp and paper mills in the US through top-down, industry-wide screening and bottom-up, chemical process modeling techniques. We estimate costs of capturing and transporting CO2 from pulp and paper mills using post-combustion amine chemisorption in the year 2026 with application of the existing federal tax credit for carbon capture and sequestration (Section 45Q). Costs are highly dependent on scenario-specific details, such as waste heat or power generation at the mill, idling or stranded assets, and proximity to suitable geologic storage opportunities. Some CCS implementation scenarios produce significant economic returns for pulp and paper mills, indicating a near-term opportunity to accelerate CCS in the US. Finally, we qualitatively assess alternative techniques for CO2 capture through process innovation, and opportunities for CO2 utilization at pulp and paper mills.

Among the various non-convectional energy resources, solar energy has great potential when it comes to conversion into electrical power.Increases efficiency of solar system is desirable for maximum power output.In order to maximisepower output, needs to keep the panels in proper angle with the sun.This paper deal with the generation using solar powerby window blinds.The proposed system ensures the optimization of the conversion of solar energy into electricity by properly orienting the panel in accordance with the position of the sun south facing window.

The recovery and utilisation of industrial excess heat has been identified as an important contribution for energy efficiency by reducing primary energy demand. Previous works, based on top-down studies for a few sectors, or regional case studies estimated the overall availability of industrial excess heat. A more detailed analysis is required to allow the estimation of potentials for specific heat recovery technologies, particularly regarding excess heat temperature profiles. This work combines process integration methods and regression analysis to obtain cogeneration targets, detailed excess heat temperature profiles and estimations of electricity generation potentials from low and medium temperature excess heat. The work is based on the use of excess heat temperature (XHT) signatures for individual sites and regression analysis using publicly available data, obtaining estimations of the technical potential for electricity generation from low and medium temperature excess heat (60–140 °C) for the whole Swedish kraft pulp and paper industry. The results show a technical potential to increase the electricity production at kraft mills in Sweden by 10 to 13%, depending on the level of process integration considered, and a lower availability of excess heat than previously estimated in studies for the sector. The approach used could be adapted and applied in other sectors and regions, increasing the level of detail at which industrial excess heat estimations are obtained when compared to previous studies.

The recovery and utilisation of industrial excess heat has been identified as an important contribution for energy efficiency by reducing primary energy demand. Previous works, based on top-down studies for a few sectors, or regional case studies estimated the overall availability of industrial excess heat. A more detailed analysis is required to allow the estimation of potentials for specific heat recovery technologies, particularly regarding excess heat temperature profiles. This work combines process integration methods and regression analysis to obtain cogeneration targets, detailed excess heat temperature profiles and estimations of electricity generation potentials from low and medium temperature excess heat. The work is based on the use of excess heat temperature (XHT) signatures for individual sites and regression analysis using publicly available data, obtaining estimations of the technical potential for electricity generation from low and medium temperature excess heat (60-140 degrees C) for the whole Swedish kraft pulp and paper industry. The results show a technical potential to increase the electricity production at kraft mills in Sweden by 10 to 13%, depending on the level of process integration considered, and a lower availability of excess heat than previously estimated in studies for the sector. The approach used could be adapted and applied in other sectors and regions, increasing the level of detail at which industrial excess heat estimations are obtained when compared to previous studies.

Chemical Looping Combustion (CLC) CO2 capture technology can be used to recover energy from municipal solid waste (MSW). In this study, techno-economic analysis of CLC of waste paper, PVC and their blends for electricity and heat generation was carried out. The process includes the chemical looping combustion section, carbon capture section and lastly, electricity generation section, and this was simulated using Chemcad software. Four scenarios were evaluated; IG-CLC (In-situ Gasification Chemical Looping Combustion) with electricity production only, and with combined heat and power (CHP), Chemical Looping Oxygen Uncoupling (CLOU) with electricity production and with combined heat and power (CHP). Based on a net capacity of 150 MW, the effect of waste paper, PVC and its blends on its net efficiency and LCOE was investigated for all four scenarios.

International audience; In this study, a system combining an anaerobic moving-bed biofilm reactor and a microbial fuel cell (MFC) was designed for simultaneous bioelectricity generation and pulp/paper wastewater (PPW) treatment. After 22 days, when hydraulic retention time (HRT) was set at 72 h, ceramsite-added MFC (C-MFC) showed better bioelectricity performance with power density of 94.5 mW/m2 and internal resistance of 35.7 Ω, as compared to the control without ceramsite (W-MFC) (56.1 mW/m2, 54.3 Ω). Chemical oxygen demand (COD) removal efficiencies of C-MFC and W-MFC were 65.6% and 51.3%, respectively. The C-MFC demonstrated its superior electrochemical performance compared to the W-MFC.

We propose a paper solar cell based on carbon nanotube (CNT)-composite papers. To fabricate this cell, we use dye-sensitized solar cells (DSCs) for generating power through the redox reaction of dyes in conjunction with CNT-composite papers, which are composite materials containing CNTs and pulp (raw paper material) that can be fabricated easily by using a method based on the Japanese washi papermaking technique. The demand for CNT applications is expected to increase due to their high conductivity and metallic or semiconducting characteristics. This CNT-composite paper can also have metallic or semiconducting characteristics based on the contained CNTs in the composite paper. We previously fabricated a DSC that generates electricity by using CNT-composite papers stacked in a typical DSC structure. However, the conversion efficiency of this DSC was just 0.188%, which is not practical. To overcome this low power generation issue, we tried improving the DSC structure by applying electrodes to the CNT-composite papers in grid patterns for efficient current collection and applying an optimally mixed dye for efficient electron excitation. Results showed that the conversion efficiency improved to 0.58%. Moreover, we demonstrated that using a mixed dye can improve the conversion efficiency of the paper DSC. We expect these types of CNT-composite papers to be used as material for new DSCs.

Due to the increasing use of intermittent renewable generation, the power grid requires more flexible resources to balance supply and demand of electricity. Steam systems with turbine-generators, which are widely used in industries, can be operated flexibly to support the power grid. Yet, the available amount of flexibility of industrial steam systems is still not clearly quantified. This study presents the method to quantify electricity generation flexibility of a typical industrial steam system with a steam turbine-generator and process heat demands. The proposed method is introduced based on a real case of an integrated pulp and paper mill in Austria. An integrated mathematical model representing the combined electricity and steam system is developed to simulate the behaviour of the on-site energy system to quantify the potential flexibility provision. Flexibility is represented as the maximum upward and downward changes in the imported electricity from the public power grid. The results demonstrate that it is possible to aggregate the flexibility of the industrial facility as a lookup table. Also, the results reflect key factors that limit the flexibility at different operating points of the turbine-generator.

Sustainable power generation for portable electronic devices is of high interest due to increasing energy demands. Miniaturized biofuel cells are well-reported for this purpose where ubiquitous fluids, like glucose or lactate, can be leveraged. However, such biofuel cells need enzymes to complete the catalysis, leading to many prevalent issues like the longevity of enzymes, complicated immobilization, additional mediators etc. Therefore, non-enzymatic glucose biofuel cells (NEGBFCs) are gaining interest due to their cost-effectiveness, high repeatability and excellent stability. However, based on our best knowledge such glucose biofuel cells are not reported in microfluidic environment, and therefore their potential is not exploited. Realization of the functionality of such NEGBFCs in a microscale is crucial to replace them with their enzymatic counterparts. In this work, for the first time, a microfluidic non-enzymatic glucose biofuel cell (μNEGBFC) is developed on a paper-based platform using metallic catalysts. The catalysts for electrocatalytic energy generation is fabricated using electrodeposition method and their detailed physicochemical characterizations are done. The μNEGBFC is capable of producing a power density of 12.5 μW/cm2 with a stable potential of 410 mV. This green power output can be used to operate low-power micro-devices and lab-on-chip sensors in a more continual and viable manner.

Paper and pulp industries consume huge amount of resources like wood and water every year and creates large amounts of solid wastes and waste water that have to be treated. Different forms of wastes are produced such as particle, solid, gas, and water during paper production. The developed wastes are usually not treated properly and waste water is mostly allowed to mix with water resources like river. So identification of some suitable methodologies to treat these wastes in an environmental-friendly way and to extract the energy from these wastes is the need of the day. This chapter focuses on the history of paper making, paper making methodologies, forms of waste generated along with their sources, and characteristics followed by the techniques for converting these wastes into useful energy. Incineration, gasification, pyrolysis, anaerobic digestion, and biodiesel production methodologies for converting paper mill wastes into energy are discussed and it is found that anaerobic digestion is a commonly used method for wastewater, whereas incineration is for solid wastes. The possibility of producing biofuels from these wastes was also found as feasible.

Current transformers (CTs) are extensively used in electrical switchyards and substations for metering and protection purposes [1] and are expected to operate properly for at least 30 years [2]. Normally, aging of CTs under service conditions is relatively slow, but they also may fail prematurely due to various reasons, such as design faults, inadequate quality during manufacture, lightning strikes, operation beyond rated conditions and inadequate maintenance [3]. Compared with other high voltage apparatus, failure of a CT can be violent or even catastrophic, causing damages to the CT itself as well as to nearby located assets and humans [4–9]. Build-up of internal pressure during a failure of a CT results in an instant fire due to burning of oil and explosion of porcelain housing, where porcelain pieces can spread to a distance up to 100 m [4], [6].

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 CO2,eq charge. Additionally, GHG emissions from grid electricity are highly influential on the results since all biofuel processes require external power. Credits for stored CO2 might be necessary for processes to be competitive, i.e. storage of separated CO2 from the syngas conditioning has an important role to play. Without CO2 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.

Paper-based analytical devices are lightweight, inexpensively produced, effective, and easily disposable; allowing for their suitable implementation in resource-limited areas. They allow effective handling of quantitative analysis in a diverse range of areas, from standard healthcare and environmental monitoring to water quality monitoring. Nonetheless, such devices often require an energy source for their complex assays or readings, preventing their effective use. Most commonly, conventional batteries are integrated into the device to serve as an energy source. However, considering its non-environmentally friendly approach to energy generation and its difficulty of being effectively disposed, a search for a new power source has begun. In light of the newly found potential of cellulose-based entities in the energy field, attention has been drawn towards a supposedly unlikely material: paper. Considering the potentials of such technology, this manuscript aims to describe the benefits of current and future technologies of paper-based devices in the energy sector. Here, we discuss the role of paper as a main platform or part of energy storage and conversion devices such as fuel cells, lithium-ion batteries, and alkaline batteries thoroughly.

We use origami to create a compact, scalable three-dimensional (3-D) biobattery stack that delivers on-demand energy to the portable biosensors. Folding allows a two-dimensional (2-D) paper sheet possessing predefined functional components to form nine 3-D microbial fuel cells (MFCs), and connect them serially within a small and single unit (5.6 cm × 5.6 cm). We load the biocatalyst Pseudomonas aeruginosa PAO1 in predefined areas that form the MFCs, and freeze-dry them for long-term storage. The biobattery stack generates a maximum power and current of 20 μW and 25 μA, respectively, via microbial metabolism when the freeze-dried cells are rehydrated with readily available wastewater. This work establishes an innovative strategy to revolutionize the fabrication, storage, operation, and application of paper-based MFCs, which could potentially make energy available even in resource-limited settings.

In pulp and paper production black liquor is burnt to recover base chemicals and to generate electricity and steam which is e.g. used in papermaking machines. In the event of paper tearing excess steam has to be condensed usually. We propose a latent thermal energy system to recover that energy and re-use it in the papermaking machines. A storage model was developed and experimentally verified by a lab-scale prototype. For the specific process, we designed a tube-bundle storage using thermally conductive HDPE as PCM and show that up to 30 MWh can be recovered per day. Finally, we describe the potential of storages to improve energy generation and efficiency in plants.

Straw pulp in China, which is the world's largest producer of this material, suffers from water and energy shortages during its entire life cycle. However, limited systematic studies have focused on these issues, and decision makers need be provided with improvement methods for the environmental performance. Thus, an impact-oriented energy and carbon coupled water footprint analysis was conducted in this study based on ISO standards. Results showed that the impact of energy consumption and carbon emissions exceeded that of water footprint. Carcinogens, non-carcinogens, and freshwater ecotoxicity also played effective roles in improving the environmental performance. Optimizing key indirect processes, including chemicals production, steam preparation, electricity generation, wood pulping, and fertilizer recovery, dominated the reduction in environmental burdens. Direct freshwater consumption and wastewater disposal played additional effective roles in controlling water footprint. The water network was thus optimized by a water pinch analysis to decrease the freshwater consumption and pollutant emissions by maximum values of 91.5% and 99.7% after optimization, respectively. Meanwhile, carbon dioxide, methane, chromium, arsenic, mercury, titanium, copper, strontium, total nitrogen, total phosphorus, BOD5, and COD were the main pollutants. Overall, the environmental impact can be further reduced by diminishing coal power ratio in national energy structure, adopting recovered steam, and considering multistage regeneration water network to cope with different water use demands.

The potential of modern regeneration boiler cold end and feedwater system integration with energy system of a paper mill is studied and measures for its better exploitation are proposed and assessed. Mathematical model has been developed, comprising material and heat balances, heat transfer equations, and steam turbine model. Its accuracy has been tested on the design and actual operation of a real system firing 70 t/h of dry solids. The simulation coped with design and measured data very well and also followed the operation changes performed in field tests excellently. Nine proposals aimed at real system efficiency improvement were assessed on the yearly benefit and simple payback period base, with yearly benefit resulting either from marginal fuel savings (scenario 1) or from condensing power production increase (scenario 2). Immediately applicable measures included deaeration at full steam pressure and heat load minimization in the first stage of the boiler feedwater regenerative heating—this novel finding contradicts the boiler design where full load regenerative heating is applied. Further measures increase the internal and external (available in paper mill) heat utilization. Their combination yielded either up to a 7 t/h internal steam consumption decrease (2.25% of nominal boiler steam output, scenario 1) or up to a 1.4 MW electricity production increase (2% of nominal steam turbine power output). Several of the proposed measures merit attention of boiler vendors and paper mills energy managers as viable tools towards low energy intensity pulp and paper mill industrial sector.

Global commodity prices for materials including paper and crude oil have slumped, lowering the value of recyclate, presenting new challenges for the Australian waste and recycling industry. This study assesses the environmental performance of managing (mixed paper and mixed plastic) recyclate in landfill, incineration and gasification-pyrolysis using life cycle assessment (LCA) for impacts including acidification, climate change, photochemical oxidation, and eutrophication potentials. The study finds environmental outcomes can be optimized by separately treating recyclate. Mixed paper treated in incineration or gasification-pyrolysis produces less greenhouse gas emissions than in landfill, whereas mixed plastic is best managed in landfill. The directional outcomes for other pollutants assessed were sensitive to the inclusion of credits from electricity production. The study is significant because waste management in Australia is now considering thermal treatment options, due to diminishing landfill capacities and perceived environmental benefits. Policy changes to waste management systems will benefit from having the ability to predict environmental outcomes based on particular waste types and materials.

Power generation from renewable sources is important for sustainable development due to the depletion of traditional fossil fuels and related environmental pollution. In this work, paper is used to generate electricity under moisture ingress. As a result, a piece of untreated print paper (1.5 cm2 in area) can induce a voltage of 0.25 V and a current of 15 nA. The power output can be conveniently tuned by changing the humidity, temperature and number of devices by simple series/parallel connections. Such paper-based moist-electric generators (PMEGs) are expected to find their applications in the daily ambient environment owing to the wide availability and low cost of paper materials. A ‘power’ book is then fabricated to prove the concept, providing new insights into moist-electric power generation and a viable approach for designing extremely simple power generators for various applications.

This Special Issue will publish selected papers from the International Symposium on Thermal Effects in Gas flow in Microscale ISTEGIM 2019 - A MIGRATE Event (http://www.istegim.eu/), 24-25 October 2019, Ettlingen, Germany. MIGRATE (www.migrate2015.eu) is a H2020 Marie Sklodowska-Curie European Training Network, intended to address some of the current challenges to innovation that faces European industry with regard to heat and mass transfer in gas-based micro-scale processes. This network of 10 participants and 6 associated partners coming from all over the European Community covers different aspects of enhanced heat transfer and thermal effects in gases: from modelling of heat transfer processes and devices, development and characterization of sensors and measurement systems for heat transfer in gas flows as well as thermally driven micro gas separators, to micro-scale devices for enhanced and efficient heat recovery in environmental, transport, telecommunications and energy generation. The MIGRATE Project presents his 2-day symposium, ISTEGIM19, during which the members of the MIGRATE network will showcase the main achievements of the project. The program will include keynote lectures, invited lectures and contributed papers.

This paper focuses on the comparison of various methods and quantity of electrical power generation in the countries as Turkey, United Arab Emirates and Germany including sources of electricity and comparison with India is highlighted. In this paper, there is an outlook of various power generation techniques adopted, and the amount of the power with the help of various means are highlighted and put for the immediate comparison. It is also discussed that a brief outlook of power generation and their comparison show the significance of the geographical, climatic and political situations emphasis on the methods of their power generations, respectively. In different countries, the nature of electrical power generation has shown with graphical form on the account of percentage utilization of energies in recent year. Various power generation methods like thermal, wind, solar, gas, nuclear, hydro electricity, other renewable energy sources, etc., are discussed in details. A detailed comparison of cost of generated power and cost of a single unit per person according to the respective country has been discussed. By knowing this, it may be analyzed that different sources of power generation can be compared with the power generated in India. With the help of this, analysis and comparing to the utilization of different types of sources for the purpose of generation of electricity by different countries can be understood including source for production of electricity as compared to renewable source of energy.

Strongly electric fish use gradients of ions within their bodies to generate stunning external electrical discharges; the most powerful of these organisms, the Atlantic torpedo ray, can produce pulses of over 1 kW from its electric organs. Despite extensive study of this phenomenon in nature, the development of artificial power generation schemes based on ion gradients for portable, wearable, or implantable human use has remained out of reach. Previously, an artificial electric organ inspired by the electric eel demonstrated that electricity generated from ion gradients within stacked hydrogels can exceed 100 V. The current of this power source, however, was too low to power standard electronics. Here, an artificial electric organ inspired by the unique morphologies of torpedo rays for maximal current output is introduced. This power source uses a hybrid material of hydrogel-infused paper to create, organize, and reconfigure stacks of thin, arbitrarily large gel films in series and in parallel. The resulting increase in electrical power by almost two orders of magnitude compared to the original eel-inspired design makes it possible to power electronic devices and establishes that biology's mechanism of generating significant electrical power can now be realized from benign and soft materials in a portable size.

This paper introduces a novel enzymatic fuel cell design that employs cellulose paper-based quasi-2D microfluidic system to supply biofuel to the enzymatic layer. The state of the art nanoarchitectural design, employing carbon nanotube-based papers for the bioelectrodes, allows a single cell to maintain 400 mV for 16 days of continuous operation in glucose solution and reach 1 mA of current output. Stacks of cells connected in series show successful performance using glucose in Gatorade® resulting in stack-cell potential of 1.8 V, employed to power a digital clock for 36 h, continuously. These designs open the possibility for obtaining enzymatic fuel cells that can run small portable devices on easily available ubiquitous liquids while addressing environmental concerns that are prevalent in traditional fuel cells. Keywords: Enzyme, Bioelectrodes, Enzymatic biofuel cells, Microfluidic system, Capillary driven flow, Bucky paper

In this paper, a comparison of the various methods and quantity of electrical power generation of countries like Australia, Argentina, New Zealand, Mexico, and India is highlighted. It is required to get the outlook of the various power generation techniques, and the amount of the power the other countries are generating. It has been also shown the power generation methods of different countries in graphical form and on the account of percentage utilization of energies in recent year. Various power generation methods like thermal, wind, solar, gas, nuclear, and hydro are been taken into consideration. With the help of this, we may analyze different sources of power generation and compare of the above four countries power generated and compared with the power generated in India. With the help of this study and comparison, it can be observed also that the utilization of different types of sources for the purpose of generation of electricity by different countries and how such countries are major dependent on thermal power source for the production of electricity as compared to renewable source of energy.

We present Self-powered Paper INterfaces (SPIN) combining folding paper creases with triboelectric nanogenerator (TENG). Embedding TENG into paper creases, we developed a design editor and set of fabrication techniques to create paper-based interfaces that power sensors and actuators. Our SPIN design editor enables users to design their own crease pattern by changing parameters, embed power generating modules into the design, estimate total power generation, and export the files. Then following the fabrication instructions, users can cut and crease materials, and assemble them to build their own interfaces. We employ repetitive push-and-pull based embodied interactions with the mechanism of paper creases and demonstrate four application examples that show new expressive possibilities applying different scales of embodied interactions.

This article presents a lifetime study of oil immersed Generator Step-Up (GSU) transformers and their remaining life expectancy which are investigated in Electricity Generation Authority of Thailand (EGAT). The GSU transformer remaining life depends on its solid insulation. The analysis of insulation strength and statistical data are applied for lifetime curve model. By this evaluation method, it can assess a remaining life of GSU transformer and maintain reliability of electric generation system. In addition, this method can support Power Development Plan (PDP) strategy to prolong the lifetime of some power plants. The lifetime curve of GSU transformers are assessed and compared with the previous study for the grid transformer lifetime.

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.

The differential pricing for peak hours encourages industrial consumers to look for independent power supplies for the period from 19 to 22 hours. This paper presents a study to identify the optimal solution for a recycled paper mill that also intends to work in that period. The factory is located in Rio Grande do Sul, in southern Brazil, and considers the use of a diesel gen set, a micro hydro power plant and possibly PV modules. Two micro hydro power plants were considered in the study, an old plant to be renewed and another to be fully implemented. The software Homer was used as a tool to determine the most feasible combination of components considered in the study. The sale of surplus power to the energy system appears as a key to viability of alternatives that are not based solely on diesel generators. The optimal solution consists of a combination of diesel generators and micro hydro power plant, in one case, and only on hydroelectric power plant in another, with a significant penetration of PV modules if its cost is reduced to 12% of the current price, selling an amount of energy equal to that which is bought. The annual water availability in one of the sites requires diesel supplement, while the other, more abundant, this supplement is not necessary.

The development of stretchable energy generation devices is indispensable for achieving stretchable, self-powered electronic systems. In this paper, a type of highly stretchable triboelectric nanogenerators made from conventional, inelastic materials such as paper is presented. It exploits a rationally designed interlocking kirigami structure and is capable of harvesting energy from various types of motions such as stretching, pressing, and twisting owing to the shape-adaptive thin film design. Energy harvested from the as-fabricated devices has been used for powering an LCD screen and lighting LED arrays. Furthermore, the paper-based devices have also been demonstrated for self-powered acceleration sensing and self-powered sensing of book opening and closing. This work introduces traditional kirigami into the development of stretchable triboelectric nanogenerators and verifies its promising applications in both power generation and self-powered sensing.

We report a novel paper-based biobattery which generates power from microorganism-containing liquid derived from renewable and sustainable wastewater which is readily accessible in the local environment. The device fuses the art of origami and the technology of microbial fuel cells (MFCs) and has the potential to shift the paradigm for flexible and stackable paper-based batteries by enabling exceptional electrical characteristics and functionalities. 3D, modular, and retractable battery stack is created from (i) 2D paper sheets through high degrees of folding and (ii) multifunctional layers sandwiched for MFC device configuration. The stack is based on ninja star-shaped origami design formed by eight MFC modular blades, which is retractable from sharp shuriken (closed) to round frisbee (opened). The microorganism-containing wastewater is added into an inlet of the closed battery stack and it is transported into each MFC module through patterned fluidic pathways in the paper layers. During operation, the battery stack is transformed into the round frisbee to connect eight MFC modules in series for improving the power output and simultaneously expose all air-cathodes to the air for their cathodic reactions. The device generates desired values of electrical current and potential for powering an LED for more than 20min.

Harvesting energy from environmental moisture is a promising technique for sustainable electric power resource. Herein, a new scalable fabrication method for flexible moisture-electric energy transformation device by dispersing or direct printing carbon dots (CDs) on paper is reported. A facile strategy for self-establishing ionic gradient on both sides of the device by constructing an asymmetric structure (the side of device is encapsulated) is proposed, which avoids prior processing of the materials for building asymmetric functional groups. The carboxyl groups on CDs near the open side of the device ionize more protons than that near the closed side, resulting in a potential drop across the device due to the concentration difference of the released protons on the two sides. The device can produce a sustainable voltage of −40 mV for over 100 min at a fixed humidity value. In addition, the device responds to direct touching of a finger or human exhalation, thus indicating its great potential for applications in electronic skins and humidity sensors.

Nowadays, multi-functional systems driven by solar energy have been explored to alleviate the crisis of energy and freshwater scarcity. However, it remains a great challenge to integrate multi-functions into one hybrid system with a monolithic material, which can harvest, convert and store solar energy synergistically. Here, we firstly propose a multi-functional carbon nanotube paper, which starts from a material level to solve these problems. The carbon nanotube paper is fabricated by vacuum filtration. It exhibits high efficiency of solar-thermal conversion. Secondly, three types of energy conversion/storage systems (e.g., solar-thermal evaporation system, solar-thermoelectric generation system, and supercapacitor) are constructed based on the carbon nanotube paper, which extend the research to a device level. The solar-thermal evaporation system shows an evaporation rate of 1.28 kg m-2h−1 under simulated sunlight irradiation of 1 kW m−2. The solar-thermoelectric generation system demonstrates a stable electric power generation with an output voltage of 100 mV under light irradiation of 1 kW m−2. The supercapacitors perform the energy storage function with an areal specific capacitance of 19.6 mF cm−2. These devices and systems can be used in freshwater generation (0.84 kg m-2h−1, sunlight irradiation of 1 kW m−2), water purification/desalination (inorganic ions rejection larger than 99.9%) and portable solar charging system (maximum output voltage of 5 V). Finally, a hybrid energy system is innovatively proposed from the system level to simultaneously produce freshwater, generate and store electric power. Through the synergetic coupling of solar conversion and storage technologies, the hybrid energy system can supply sustainable freshwater and electricity for remote areas in daily life, highlighting the superiority of multi-energy (thermal energy, electrical energy, and electrochemical energy) complementary.

Two-step activation of paper batteries has been successfully demonstrated to provide quick activation and to supply high power to credit card-sized biosystems on a plastic chip. A stack of a magnesium layer (an anode), a fluid guide (absorbent paper), a highly doped filter paper with copper chloride (a cathode) and a copper layer as a current collector is laminated between two transparent plastic films into a high power biofluid- and water-activated battery. The battery is activated by two-step activation: (1) after placing a drop of biofluid/water-based solution on the fluid inlet, the surface tension first drives the fluid to soak the fluid guide; (2) the fluid in the fluid guide then penetrates into the heavily doped filter paper with copper chloride to start the battery reaction. The fabricated half credit card-sized battery was activated by saliva, urine and tap water and delivered a maximum voltage of 1.56 V within 10 s after activation and a maximum power of 15.6 mW. When 10 k? and 1 K? loads are used, the service time with water, urine and saliva is measured as more than 2 h. An in-series battery of 3 V has been successfully tested to power two LEDs (light emitting diodes) and an electric driving circuit. As such, this high power paper battery could be integrated with on-demand credit card-sized biosystems such as healthcare test kits, biochips, lab-on-a-chip, DNA chips, protein chips or even test chips for water quality checking or chemical checking.

The Swedish pulp and paper industry has gone through a strategic change in its approach to electricity production and consumption over the past decade. This paper documents this reorientation, which includes increased on-site electricity production, investments and investment plans for wind power, and new partnerships concerning investments in electricity production assets. We also assess the extent to which these changes can be attributed to key energy and climate policies. Our analysis shows that this strategic reorientation has been driven by changes in the underlying economic conditions for the pulp and paper industry, in particular increases in the price of electricity following the Swedish energy market reform in 1996, and the introduction of the EU ETS. The scheme for tradable renewable electricity certificates, on the other hand, has provided a new source of income. While these market-based signals and responses are the most dominant drivers of strategic change, cognitive changes in the pulp and paper industry have also played a role in the strategic reorientation. The cognitive changes concerning the functioning of the electricity market, i.e. the pricing of electricity and influence of the EU ETS, have been particularly important in this regard.

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.

Developing lightweight, flexible and sustainable sensor networks with miniaturized integration and functionality for the Internet of Things (IoT) remains a challenge and an urgent demand for the next-generation electronic devices. Paper-based electronics, which represents one of the main green electronics in the future, have been considered as one of the most exciting technologies to meet the consumption of the frequently upgraded electronics. Here, we presented an ultrathin (about 200 µm) and lightweight paper-based self-powered system that consists of a paper-based triboelectric/piezoelectric hybrid nanogenerator and a paper-based supercapacitor. Under human motions such as flipping the page and moving the book/document, the as-fabricated self-powered system built-in the smart book/document was capable of sustaining power for portable devices, such as continuously driving LEDs and the temperature/humidity sensor. With the signal-processing circuit, the paper-based system was further developed into a wireless human-machine interaction system for documents management and smart reading. The ultrathin and highly flexible characteristics of the self-powered system not only endow the device with power generation feature for portable devices, but also build up the wireless human-machine interactions in developing potential applications for the IoT.