Energy Recovery Technologies Research Articles

Energy Recovery and Waste Reduction Analysis of a Full-scale Anaerobic Digestion Food Waste Plant in Shandong

Methane (CH4) generation via anaerobic digestion is a promising technology for energy recovery and waste reduction. In this study, the techno-economic analysis of a CH4 production from food waste (FW) was carried out. An anaerobic digestion FW plant was capable of treating 100 t/d, which was authorized to operate for 17 years. The pretreatment and anaerobic digestion processes were used to produce CH4 and recovery crude oil. The total investment and annual operational costs of FW treatment plant were 42,786,030 and 2413380 RMB, respectively, while the annual pre-tax annual incomes was 6941293.6 RMB. The return on investment and payback period were 7.79% and 12.84 years, respectively. The daily treatment quantity of FW is 21t, the treatment plant starts to make profits. The assessment results indicated that FW treatment was a comprehensive engineering system, which was strongly associated with society, economy, environment and technology.

Development of a Comprehensive Driving Cycle for Construction Machinery Used for Energy Recovery System Evaluation: A Case Study of Medium Hydraulic Excavators

Energy recovery and hybrid power technology are new directions in construction machinery energy-saving research. Thus far, however, no uniform standard method exists to evaluate the efficiency of novel energy-saving concept systems in early stages of development. Efficiency assessment is valuable and credible only by relying on driving cycles that are consistent with actual data. As representative products of construction machinery, hydraulic excavators are multifunctional, object-uncertain, and heavily influenced by operator habits. It is therefore challenging to develop standard excavator driving cycles. Aiming at the energy efficiency evaluation of new energy-saving products characterized by energy recovery and power system optimization, taking medium-sized hydraulic excavator as an example, this paper proposes an evaluation method of energy-saving efficiency and a classification construction method of comprehensive driving cycle of hydraulic excavator based on actual operating data with load demand power and boom recoverable power as combined variables. First, based on the analysis of general driving cycle variables for excavators with different energy-saving schemes, a load demand power model and boom recoverable power model based on machine sensing data are established. Second, 10 excavators were selected at different locations in southern China, and 30 days of real-world working data were recorded. Third, according to the periodic characteristics of working data, a method for dividing microcycle operation structure is proposed. The microcycle sample space based on the data conversion of working data is constructed and classified via the clustering algorithm. Finally, a comprehensive excavator driving cycle based on the classification results is constructed through the Markov method. Results show that the energy-saving efficiency of the three classification driving cycles was 17.45%, 13.60%, and 11.88%, respectively; the comprehensive energy-saving efficiency was 15.76%. The deviations in maximum load demand power and maximum boom recoverable power between the constructed comprehensive cycle and the sample space were 7.81% and 8.61%; the average deviation of characteristic parameters was 4.26%. The comprehensive driving cycles can fairly reflect the general characteristics of real-world working conditions. The proposed construction method of comprehensive driving cycles based on sample space is therefore reliable and holds great promise for evaluating the energy-saving efficiency of new energy-saving concept systems.

A Survey of Powertrain Technologies for Energy-Efficient Heavy-Duty Machinery

This article presents a comprehensive, multidisciplinary overview of the development of powertrain technologies for energy-efficient heavy-duty earthmoving machines. The heavy-duty earthmoving equipment industry has been among the biggest contributors to emissions globally. However, due to high power demand and multidisciplinary powertrain structures, improving the energy efficiency of heavy-duty mobile machines has been a pressing and challenging task in the industry. To cope with this challenge, hydraulics and power electronics (PE) have been the key driving forces. As such, the relative developments in both fields are covered in this article. For hydraulics, developments of efficient hydraulic circuits will be overviewed in detail along with the introduction of hydraulic energy recovery technologies. In addition, developments of PE architectures in hybrid and electrified machines will be introduced. Furthermore, potential medium-voltage dc mining site power distribution and the valves of wide bandgap devices will also be discussed with the hope to open up new research opportunities in PE. Moreover, emerging hybrid electrohydraulic drive technology is introduced. Based on the overview in this article, it is anticipated that electrohydraulic hybridization will be the future trend in the earthmoving machine industry. Deeper collaboration between the two areas is desirable.

Piezoelectric Energy Harvesting for Flapping Wing Micro Air Vehicle and Flapping Wing Sensing Based on Flexible Polyvinylidene Fluoride

The flapping wing micro air vehicle (FWMAV) has been attracting lots of interest since the 1990s and is one of the research hotspots in microminiaturization design. However, along with the miniaturization of FWMAV development, flight endurance becomes the bottleneck that significantly impedes the rapid development for these aircrafts because of the critical limit in energy supply due to the limited overall size and weight. In this paper, energy recovery technology was developed for FWMAV with the new type polyvinylidene fluoride (PVDF) piezoelectric wing which could generate the electric potential energy caused by the wing deformation due to the characteristics of the PVDF material. A single crank double rocker mechanism flapping platform was designed to test the deformation energy collection effect and aerodynamic lift. The PVDF wing surface was divided into 16 grid areas to be measured respectively. The lift, output voltage and output power variations for the different flapping frequency was successfully obtained in tests. By analyzing test data, if could be found that the output power could reflect the flutter condition without equipping other sensors and adding extra weight to the aircraft. Moreover, when the flapping frequency was accelerated to 12 Hz, the output power and root mean square (RMS) voltage could increase to 21 μW and 6 V respectively, which is enough to power micro electronic devices such as LED lights.

Methanogenic crude oil degradation induced by an exogenous microbial community and nutrient injections

Microbial potential of crude oil degradation coupled to methane production has attracted much attention as a basis for microbial enhanced energy recovery (MEER) technology. Here we performed laboratory incubation experiments mimicking in situ temperature and pressure conditions of subsurface oil reservoirs to evaluate the effectiveness of biological augmentation and stimulation for MEER. Using our high temperature and pressure incubation system, we successfully obtained a microbial community capable of methanogenic crude oil degradation from the Yamagata oil reservoir in Japan. To evaluate the potential of biological augmentation, we inoculated the microbial culture from Yamagata into production water from the Akita oil reservoir in which the indigenous microbial community cannot degrade crude oil. We observed methane production associated with toluene degradation, indicating that biological augmentation could be successful. We also evaluated the potential of biological stimulation, i.e. the effects of supplementing with different nutrients on crude oil degradation using the Yamagata oil reservoir sample. Intriguingly, addition of specific yeast extracts (YEs) resulted in notably enhanced methane production associated with the degradation of longer-chain n-alkanes as well as toluene. We further assessed the effectiveness of combining the biological augmentation and stimulation by inoculating the microbial culture from Yamagata together with the effective YE into the Akita production water, and found a large amount of methane production coupled to toluene and n-alkane degradation during the incubation. Taken together, our results suggest that the bio-augmentation and stimulation strategies demonstrated here could be a powerful tool for energy recovery from petroleum reservoirs both with and without innate crude oil degradation.

Biological Reduction of Nitric Oxide for Efficient Recovery of Nitrous Oxide as an Energy Source.

Chemical absorption-biological reduction based on Fe(II)EDTA is a promising technology to remove nitric oxide (NO) from flue gases. However, limited effort has been made to enable direct energy recovery from NO through production of nitrous oxide (N2O) as a potential renewable energy rather than greenhouse gas. In this work, the enhanced energy recovery in the form of N2O via biological NO reduction was investigated by conducting short-term and long-term experiments at different Fe(II)EDTA-NO and organic carbon levels. The results showed both NO reductase and N2O reductase were inhibited at Fe(II)EDTA-NO concentration up to 20 mM, with the latter being inhibited more significantly, thus facilitating N2O accumulation. Furthermore, N2O accumulation was enhanced under carbon-limiting conditions because of electron competition during short-term experiments. Up to 47.5% of NO-N could be converted to gaseous N2O-N, representing efficient N2O recovery. Fe(II)EDTA-NO reduced microbial diversity and altered the community structure toward Fe(II)EDTA-NO-reducing bacteria-dominated culture during long-term experiments. The most abundant bacterial genus Pseudomonas, which was able to resist the toxicity of Fe(II)EDTA-NO, was significantly enriched, with its relative abundance increased from 1.0 to 70.3%, suggesting Pseudomonas could be the typical microbe for the energy recovery technology in NO-based denitrification.

PROTOTYPING MESH TURBINE WITH THE JET CONTROL SYSTEM

The oil and gas market is unstable, which requires intensification of the exploratory research for working advanced and inexpensive pumping and compressor equipment out. Such equipment is crucial for more efficient hydrocarbon production. The ongoing research work is being undertaken to search and study new technical opportunities to develop advanced pumping and compressor equipment adapted to the complicated conditions of oil and gas production in solid abrasive particles in the flow of the pumped medium. New technology for gas compression has been evolved and further patented. The technology utilized a jet compressor unit to assist a turned on ejector while in the cyclic mode. Pulsed cycling of the ejector in contrary to continuous operation, increases the compression ratio of the multiplied gas. The energy recovery technology has been evolved, and further patented io increase the energy efficiency in the jet compressor unit. This technology applies a particular mesh turbine located at the flow part. The evolvement of smart turbines and compressor units was thoroughly researched. 3D-models have been developed in SOLIDWORKS 3D CAD system. The FloEFD software package of computational fluid dynamics has been used for computer modeling. In laboratory conditions, the performance of the mesh turbine prototype equipped with the jet control system has been successfully tested. Efficient and cheap compressor units solve many urgent issues in production connected with hydrocarbons extraction in harsh environments and those, which occur at the later stages of developing oil and gas fields. Specific research results can be used in other domains, including energy, transport, and robotics.

Exploring untapped effect of process conditions on biochar characteristics and applications

The aim of the current review is to examine the effect of process conditions on biochar characteristics and their impacts on a wide range of potential biochar applications for its commercialization. Biochar is a solid residue produced by thermochemical conversion from different biomass. In this study, a comprehensive discussion has been made on physiochemical characteristics of biochar such as carbon content, mineral content, volatile matter, surface area, pore structure, pore distribution, and electrical conductivity that are depend on several critical factors, including process temperature, heating rate, type of gasifier and biomass, and biomass composition. In addition, some other unique properties of biochar like high surface area and porous structure make it a promising cheap source for the production of carbon-based catalysts for energy recovery technologies like gasification, anaerobic digestion, and pyrolysis, adsorbents material in wastewater treatment, activated carbons, microbial fuel cells (MFC) electrodes, energy storage material, and the preparation of supercapacitors has been reviewed. Most importantly, the status of char technology for different application and the barriers, problems, and research gaps are also mentioned for future research and development for researchers, private and public investors.

Performance of sludge degradation, mineralization and electro-energy harvesting in a sludge treatment electro-wetland: Insight into the sludge loading rate

In order to enhance the performance of sludge treatment wetland (STW), microbial electrochemical system (MES) was introduced into a conventional sludge treatment wetland. A sludge treatment electro-wetland (STEW) was specially developed and investigated for its performance in sludge treatment and bioenergy production. The study investigated the performance of the STEW in terms of sludge organic degradability, sludge stabilization and the capability of bioelectricity generation at different sludge loading rates (SLR) of 50, 95, 125 kg TS/year·m2. The quality of the final residual sludge product for agricultural reuse was also characterized. Results revealed that the highest power output (0.790 V of voltage and 0.229 W/m3 of power density) of STEW was achieved with the highest SLR (125 kg TS/year·m2). The best sludge treatment efficiency (7.07 % of dewatering rate, 40.43 % of volatile solid (VS) removal and 80.95 % of total chemical oxygen demand (TCOD) removal) of STEW were achieved with proper SLR of 95 kg TS/year·m2. After resting period, the nutrient concentrations in the residual sludge were quite low (total nitrogen of 2.86 % total solid (TS) and total phosphorous of 0.93 %TS), and heavy metals and faecal bacteria (Salmonella spp. and Escherichia coli) concentrations remained within the current legal limits for land application of the sludge. Experiments showed that the STEW system demonstrated a satisfactory efficiency for sludge dewatering and mineralization in spite of the high sludge loading rate and recycled the bioenergy simultaneously. The results also illustrated that the STEW was a promising technology for simultaneous sludge treatment and energy recovery.

Liquid Thermocells Enable Low-Grade Heat Harvesting

Recently, two Science papers tackled the challenge of harvesting low-grade heat via liquid thermocells. One combines TGC and TDC to significantly enhance thermopower by an order of magnitude, and the other reveals the selectively thermosensitive crystallization/dissolution at two electrodes. These intriguing and inspiring advances in terms of materials, mechanisms, and performances are briefly introduced, and some remaining challenges and future directions are outlined for further thermopower improvement and practical implementation.

Effect of Interstage Hydrothermal Treatment on Anaerobic Digestion of Sewage Sludge: Speciation Evolution of Phosphorus, Iron, and Sulfur

Anaerobic digestion (AD) with interstage hydrothermal treatment (HT) (i.e., AD–HT–AD) is an emerging technology for energy and nutrient recovery from sewage sludge. Yet, systematic understanding on...

A freestanding carbon submicro fiber sponge as high-efficient bioelectrochemical anode for wastewater energy recovery and treatment

Microbial fuel cells (MFCs), as a typical kind of microbial electrochemical technologies (METs), can achieve energy recovery and wastewater treatment. Microbial adhesion on electrodes directly affects microbe-electrode interactions, determining the performance of electricity generation and organic degradation. The anode with suitable structure and operation mode can reduce the limitation of fiber diameter-structure-interface trade-off to enhance microbe-electrode interaction. Here, we fabricated a carbon submicro fiber sponge with fiber diameter close to the size of electrogenic microorganism and operated it in filtration mode to greatly improve energy conversion. The carbon submicro fiber sponge exhibits a superior current yield of 17.4 A m−2 in the polarization curve with high electrochemical activity in MFC, which is 74% higher than that of the commonly used carbon fiber cloth anode. A higher chemical oxygen demand removal rate of 2.9 kg m−3 d−1 is obtained with this novel anode (1.3-fold that of the benchmark). The linkage mechanism of electricity generation and organic degradation is analyzed. Moreover, a long-term stability is demonstrated with excellent current production after the operation over 2 years. Our results indicate that this carbon fiber sponge has remarkable application potential in microbial electrochemical technologies for energy recovery from wastewater.

Municipal solid waste (MSW) - competitive raw materials for combustible materials obtaining

Waste-to-energy projects can be classified as a complementary technology for energy recovery from nonrecyclable municipal waste fractions and should therefore not compete with measures to reduce, reuse, and recycle materials. The article presents the characterization of some treated municipal solid wastes as competitive raw materials for combustible materials obtaining. Samples with lignocellulosic and polymeric composition were analyzed, namely 3 samples of SRFs (solid recovered fuels) used as secondary raw material in cement plants, SRF1, SRF2, SRF3; a sample of RDF, consisting of household waste; a sample of fluff (a homogeneous mixture of non-hazardous waste - selected, mechanically treated and dried) used as a secondary raw material in cement plants; 4 samples of municipal solid waste, fractions smaller than 100 mm, after a bio-drying process, with composition: paper and cardboard (70-80%), wood (6-15%), plastic (6-10%), glass and metal (3-14%), MBU1, MBU2, MBU3, MBU4. The waste samples were characterized in terms of technical and elementary characteristics and the ash (obtained by the sample incineration) behavior in the combustion process. The mineral matter was investigated by the X-ray fluorescence analytical technique using the Rigaku CG X-ray Spectrofluorimeter. The analysis of the indices used for the slagging and deposit formation risks evaluation shows that the analyzed samples present an obvious risk of melt formation and deposits, due to a high content of base oxides and silicon oxide.

Robust model predictive control for a nanofluid based solar thermal power plant

Among the several technologies for solar energy recovery, parabolic solar collectors have emerged as one of the most promising due to their performance, which can be enhanced if nanofluids are employed as heat transfer fluids instead of the traditional alternatives. The inherent time-dependent behavior of solar radiation profiles forces the solar thermal plants to be operated aided with controllers able to reject these strong disturbances. While traditional controllers can be employed for this aim, more advanced techniques such as Model Predictive Control are suggested since this optimal-control based method can be tuned to minimize operating costs, among some other features. The main objective of this work is to implement an MPC controller to a nanofluid-based solar thermal power plant in order to evaluate its performance to reject disturbances on the solar radiation profile in an efficient manner. An off-line nonlinear programming optimization was deployed so we could compare the response of the on-line MPC implementation on a strict enough basis. Furthermore, the performance of MPC controllers is affected by how well does the modeling of the system is able to stick to reality, thus, it is important to test if the controller is robust enough to deal with uncertainty that might be introduced as modeling errors. Results indicate that MPC controllers are suitable for their implementation on these kinds of power plants since they steer the system to achieve desired conditions by smoothly manipulating the decision variable, even in the scenarios where a substantial cascade-effect modeling error was imposed in the parameters of the nanofluid.

Life cycle assessment of Portland cement production in Myanmar

Cement manufacturing is associated with global and local environmental issues. Many studies have employed life cycle assessment (LCA) to evaluate the environmental impacts from cement production and investigate measures to improve environmental performance. However, there have not been any scientific studies assessing the impacts of the Myanmar cement industry on the environment. In this study, environmental impacts of the Myanmar cement industry were evaluated using LCA and key contributors to major environmental impacts were identified. This study follows the principles outlined by the International Organization for Standardization (ISO 14040:2006 and ISO 14044:2006) to conduct LCA of the cement industry in Myanmar. The functional unit considered is 1 tonne of Portland cement, and a cradle-to-gate analysis was conducted. The input data (raw materials, energy, electricity, and transportation) were collected from 8 cement plants in Myanmar, but data about raw material extraction were adapted from the literature. The output data (emissions to air) were estimated based on the IPCC guidelines, the EMEP/EEA air pollutant emission inventory guidebooks and the US EPA Detonation of explosives; an AP-42 update. LCAs of specific cement plants were implemented, and both midpoint environmental impacts and endpoint damage categories were assessed based on the ReCiPe 2016 method. The results showed that major environmental impacts from the Myanmar cement industry include climate change, photochemical oxidant formation damaging ecosystem quality, fine particulate matter formation, terrestrial acidification and fossil resource scarcity. They were assessed to account for about 80, 0.5, 18, 0.6 and 0.4% of the overall environmental burdens from cement manufacturing, respectively. Human health damage was the most affected category. Key contributors to these major impacts were found to be CO2, NOx, SO2 and PM2.5 emissions, mostly from the clinker production step. In order to mitigate these environmental impacts and initiate sustainable development in this industrial sector in Myanmar, appropriate mitigation options, including fuel and energy saving, and the use of alternative fuels and materials need to be considered. Through this study, the contribution of the Myanmar cement industry to environmental impacts in a life cycle perspective was investigated and key environmental hotspots were identified in order to suggest mitigation options for the sustainable development of this industrial sector. Based on the study results, some improvement measures should be considered, which include upgrading the cement manufacturing process, increasing the share of clinker substitutes, utilizing alternative fuels, optimizing energy efficiency and implementing energy recovery technologies.

Anaerobic digestion based waste-to-energy technologies can halve the climate impact of China’s fast-growing food waste by 2040

Food waste (FW) has become a global sustainability challenge due partly to its significant environmental impacts (e.g., greenhouse gas (GHG) emissions) from traditional treatment methodologies such as landfill and incineration. This is particularly the case for developing countries, for example over 90% of FW in China is currently blended with municipal solid waste and disposed of by landfilling and incineration. The anaerobic digestion (AD) technologies for energy recovery, however, has often been identified as an effective approach for mitigating FW treatment related GHG emissions. In order to benchmark and quantify such reduction potentials, a dynamic model has been built to characterize the generation and flow of FW and treatment associated GHG emissions in China from 2001 to 2040. Our results show that the total FW generation from household and catering sectors reached 170 ± 30 Mt in 2018 and will steadily increase to approximately 220 ± 42 Mt by 2040. Accordingly, the FW treatment related GHG emissions reached 137 ± 26 Mt CO2e in 2018 and would rise to approximately 180 Mt±33 CO2e by 2040 if waste management continues with the current pattern in a Business As Usual (BAU) scenario. Compared to the BAU scenario, the scenarios subject to AD technology implementation (from conservative to optimistic) could significantly reduce GHG emissions and ensure a proportional contribution of this sector to China’s national emission reduction goal (55% by 2025 and 65% by 2030 compared to 2005). Specifically, a cumulative amount of approximately 1.9 Bt CO2e could be mitigated between 2019 and 2040 under the optimistic scenario (with 60%, 80%, and 80%, respectively, of household food waste, catering food waste, and waste cooking oil treated by AD). These findings could not only inform evidence-based policy making to facilitate the waste-to-energy development for FW treatment in China, but also shed light on the sustainable FW management and AD technology implementation in other developing countries.

Thermodynamic and Economic Feasibility of Energy Recovery from Pressure Reduction Stations in Natural Gas Distribution Networks

A big amount of the pressure energy content in the natural gas distribution networks is wasted in throttling valves of pressure reduction stations (PRSs). Just a few energy recovery systems are currently installed in PRSs and are mostly composed of radial turboexpanders coupled with cogeneration internal combustion engines or gas-fired heaters providing the necessary preheating. This paper clarifies the reason for the scarce diffusion of energy recovery systems in PRSs and provides guidelines about the most feasible energy recovery technologies. Nine thousand PRSs are monitored and allocated into 12 classes, featuring different expansion ratios and available power. The focus is on PRSs with 1-to-20 expansion ratio and 1-to-500 kW available power. Three kinds of expanders are proposed in combination with different preheating systems based on boilers, heat pumps, or cogeneration engines. The goal is to identify, for each class, the most feasible combination by looking at the minimum payback period and maximum net present value. Results show that small size volumetric expanders with low expansion ratios and coupled with gas-fired heaters have the highest potential for large-scale deployment of energy recovery from PRSs. Moreover, the total recoverable energy using the feasible recovery systems is approximately 15% of the available energy.

Evaluation of electricity production from paper industry wastewater by Cellulomonas iranensis LZ-P1 isolated from giant panda

Microbial fuel cell (MFC) is considered to be a sustainable technology for cellulosic waste treatment and energy recovery; however, studies on cellulose-degrading exoelectrogens are scarce. Giant panda gut microbiota may provide potential cellulose-degrading exoelectrogens due to consumption of high-fiber diet. In this study, strain LZ-P1 isolated from giant panda gut simultaneously showed cellulose-degrading and electricity-generating characteristics. 16S rRNA gene sequence revealed 99% homology with Cellulomonas iranensis. Results showed that the strain generated 1.08 U/mL endoglucanase and 180 mV electricity when cellulose was used as the sole carbon source. Genome sequence confirmed that strain LZ-P1 possessed complete cellulose degradation and extracellular electron transfer pathways. Proteomic analysis further confirmed that the enzymes involved in cellulose-degradation and extracellular electron transport were remarkably up-regulated, including endoglucanases, riboflavin biosynthesis protein, and cytochrome C oxidase. When strain LZ-P1 was applied to MFC-mediated paper recycling wastewater treatment, a maximum power density of 44.05 mW/m2 and 8.72% coulombic efficiency were recovered in 72 h. Therefore, strain LZ-P1 would be a potential candidate for cellulosic waste management and energy recovery.

Preparation and performance study of a new type of Tile transducer for roadway applications

In recent years, piezoelectric technology for recovery of road vibration energy has gained widespread attention. Most research in this field thus far has examined different piezoelectric materials and evaluated their feasibility in field tests, but less attention has been devoted to different transducer structures. In this study, a new type of Tile transducer was developed for roadway applications. The Tile transducer exhibited good vibration absorption effect and energy harvesting efficiency at low-frequency vibration. This study tested the Tile transducer under the supported boundary condition, and analyzed the influence of the curvature of the Tile transducer on the energy harvesting efficiency with regard to the electromechanical conversion performance and structural strength. When the excitation frequency was 10 Hz and load was 500 N, the total power of the Plane transducer was 0.59 mW. Under the same load condition, the total power of the Tile transducer was 15.44 mW, which was 26-fold higher than that of the Plane transducer. An ultimate compressive bearing capacity test and fatigue test of the Tile transducer were then carried out, and the fatigue failure mode was analyzed. The test results prove that the Tile transducer had stable and lasting structural performance.

Efficient bioanode from poultry feather wastes-derived N-doped activated carbon: Performance and mechanisms

Bioelectrochemical systems have gained great interest as a viable wastewater treatment and energy recovery technology. How to achieve the efficient interfacial electron transfer from microbes to the electrode and reduce the cost are challenges of bioelectrochemical systems. This study demonstrated that the goose feather-derived N-doped activated carbon could be adopted as the effective anode modifier to improve the bioanode performance of bioelectrochemical systems. Various electrochemical characterizations showed that both the electrochemical activity and electron transfer efficiency of the electrodes were improved after modification with the goose feather-derived N-doped activated carbon. By using Shewanella oneidensis MR-1 inoculated bioelectrochemical systems with the goose feather-derived N-doped activated carbon-modified anode, a current density of 0.96 ± 0.03 A/m2 was achieved, which was about 2 times higher than that without modification. Further analysis revealed a simultaneous enhancement of direct and flavins-mediated extracellular electron transfer after the modification with the goose feather-derived N-doped activated carbon. This enhanced extracellular electron transfer could be not only attributed to the intense interaction between cytochromes OmcA/MtrC and the goose feather-derived N-doped activated carbon, but also due to the improved flavins redox reaction on the goose feather-derived N-doped activated carbon-modified anode surface. This study broadens the recipe of bioanode of BESs via rational use of natural solid waste materials.