35 results on '"Nabin Aryal"'
Search Results
2. Freestanding and flexible graphene papers as bioelectrochemical cathode for selective and efficient CO2 conversion
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Nabin Aryal, Arnab Halder, Minwei Zhang, Patrick R. Whelan, Pier-Luc Tremblay, Qijin Chi, and Tian Zhang
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Medicine ,Science - Abstract
Abstract During microbial electrosynthesis (MES) driven CO2 reduction, cathode plays a vital role by donating electrons to microbe. Here, we exploited the advantage of reduced graphene oxide (RGO) paper as novel cathode material to enhance electron transfer between the cathode and microbe, which in turn facilitated CO2 reduction. The acetate production rate of Sporomusa ovata-driven MES reactors was 168.5 ± 22.4 mmol m−2 d−1 with RGO paper cathodes poised at −690 mV versus standard hydrogen electrode. This rate was approximately 8 fold faster than for carbon paper electrodes of the same dimension. The current density with RGO paper cathodes of 2580 ± 540 mA m−2 was increased 7 fold compared to carbon paper cathodes. This also corresponded to a better cathodic current response on their cyclic voltammetric curves. The coulombic efficiency for the electrons conversion into acetate was 90.7 ± 9.3% with RGO paper cathodes and 83.8 ± 4.2% with carbon paper cathodes, respectively. Furthermore, more intensive cell attachment was observed on RGO paper electrodes than on carbon paper electrodes with confocal laser scanning microscopy and scanning electron microscopy. These results highlight the potential of RGO paper as a promising cathode for MES from CO2.
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- 2017
- Full Text
- View/download PDF
3. Highly Conductive Poly(3,4-ethylenedioxythiophene) Polystyrene Sulfonate Polymer Coated Cathode for the Microbial Electrosynthesis of Acetate From Carbon Dioxide
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Nabin Aryal, Pier-Luc Tremblay, Mengying Xu, Anders E. Daugaard, and Tian Zhang
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microbial electrosynthesis ,carbon dioxide ,PEDOT:PSS ,acetogens ,acetate ,General Works - Abstract
Microbial electrosynthesis (MES) is a bioelectrochemical technology developed for the conversion of carbon dioxide and electric energy into multicarbon chemicals of interest. As with other biotechnologies, achieving high production rate is a prerequisite for scaling up. In this study, we report the development of a novel cathode for MES, which was fabricated by coating carbon cloth with conductive poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) polymer. Sporomusa ovata-driven MES reactors equipped with PEDOT:PSS-carbon cloth cathodes produced 252.5 ± 23.6 mmol d−1 acetate per m2 of electrode over a period of 14 days, which was 9.3 fold higher than the production rate observed with uncoated carbon cloth cathodes. Concomitantly, current density was increased to −3.2 ± 0.8 A m−2, which was 10.7-fold higher than the untreated cathode. The coulombic efficiency with the PEDOT: PSS-carbon cloth cathodes was 78.6 ± 5.6%. Confocal laser scanning microscopy and scanning electron microscopy showed denser bacterial population on the PEDOT:PSS-carbon cloth cathodes. This suggested that PEDOT:PSS is more suitable for colonization by S. ovata during the bioelectrochemical process. The results demonstrated that PEDOT: PSS is a promising cathode material for MES.
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- 2018
- Full Text
- View/download PDF
4. Alternative of Biogas Injection into the Danish Gas Grid System—A Study from Demand Perspective
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Nabin Aryal and Torben Kvist
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biogas ,Wobbe index ,gas grid ,biogas upgrading ,biogas introduction ,Chemistry ,QD1-999 - Abstract
The Danish government has set an ambitious target to achieve 100% fossil independence across all energy sectors, which demands optimum utilization of renewable energy sources, such as wind and biogas, by 2050. Biogas production has increased, and the upgrading of biogas offers a broad range of applications, such as transportation, and gas grid injection for downstream utilization. The biogas has to meet natural gas quality prior to injection into the gas grid system. The investment costs of the gas grid, upgrading cost, and gas compression costs are the major challenges for integrating the biogas into the existing gas infrastructure. In this investigation, the Wobbe index (WI) for raw biogas and upgraded biogas was measured to evaluate the scenario for biogas injection into the gas grid system. It was found that raw biogas has to improve its WI from 28.3 MJ/m3(n) to a minimum of 50.76 MJ/m3(n) via upgrading, and compressed to 40 bar system, to supply the gas grid system for trading. Then, yearly gas consumption by larger gas consumers was studied to evaluate the alternative approach of biogas utilization to save upgrading and compression costs for gas grid injection.
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- 2018
- Full Text
- View/download PDF
5. Developing a biogas centralised circular bioeconomy using agricultural residues - Challenges and opportunities
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Lu Feng, Nabin Aryal, Yeqing Li, Svein Jarle Horn, and Alastair James Ward
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Environmental Engineering ,Circular economy ,Nutrient recycling ,Anaerobic digestion ,Environmental Chemistry ,Biogas ,Pollution ,Waste Management and Disposal ,Waste management - Abstract
Anaerobic digestion (AD) can be used as a stand-alone process or integrated as part of a larger biorefining process to produce biofuels, biochemicals and fertiliser, and has the potential to play a central role in the emerging circular bioeconomy (CBE). Agricultural residues, such as animal slurry, straw, and grass silage, represent an important resource and have a huge potential to boost biogas and methane yields. Under the CBE concept, there is a need to assess the long-term impact and investigate the potential accumulation of specific unwanted substances. Thus, a comprehensive literature review to summarise the benefits and environmental impacts of using agricultural residues for AD is needed. This review analyses the benefits and potential adverse effects related to developing biogas-centred CBE. The identified potential risks/challenges for developing biogas CBE include GHG emission, nutrient management, pollutants, etc. In general, the environmental risks are highly dependent on the input feedstocks and resulting digestate. Integrated treatment processes should be developed as these could both minimise risks and improve the economic perspective.
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- 2023
6. Surface-modified activated carbon for anaerobic digestion to optimize the microbe-material interaction
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Nabin Aryal, Lu Feng, Shuai Wang, and Xuyuan Chen
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Environmental Engineering ,Environmental Chemistry ,Pollution ,Waste Management and Disposal - Published
- 2023
7. Microbial electrosynthesis: is it sustainable for bioproduction of acetic acid?
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Behzad Haji Mirza Beigi, Nabin Aryal, Jhuma Sadhukhan, and Siddharth Gadkari
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business.industry ,General Chemical Engineering ,Microbial electrosynthesis ,Industrial fermentation ,02 engineering and technology ,General Chemistry ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,Pulp and paper industry ,01 natural sciences ,Bioproduction ,Renewable energy ,chemistry.chemical_compound ,chemistry ,Yield (chemistry) ,Carbon dioxide ,Environmental science ,Production (economics) ,0210 nano-technology ,business ,Energy source ,0105 earth and related environmental sciences - Abstract
Microbial electrosynthesis (MES) is an innovative technology for electricity driven microbial reduction of carbon dioxide (CO2) to useful multi-carbon compounds. This study assesses the cradle-to-gate environmental burdens associated with acetic acid (AA) production via MES using graphene functionalized carbon felt cathode. The analysis shows that, though the environmental impact for the production of the functionalized cathode is substantially higher when compared to carbon felt with no modification, the improved productivity of the process helps in reducing the overall impact. It is also shown that, while energy used for extraction of AA is the key environmental hotspot, ion-exchange membrane and reactor medium (catholyte & anolyte) are other important contributors. A sensitivity analysis, describing four different scenarios, considering either continuous or fed-batch operation, is also described. Results show that even if MES productivity can be theoretically increased to match the highest space time yield reported for acetogenic bacteria in a continuous gas fermenter (148 g L−1 d−1), the environmental impact of AA produced using MES systems would still be significantly higher than that produced using a fossil-based process. Use of fed-batch operation and renewable (solar) energy sources do help in reducing the impact, however, the low production rates and overall high energy requirement makes large-scale implementation of such systems impractical. The analysis suggests a minimum threshold production rate of 4100 g m−2 d−1, that needs to be achieved, before MES could be seen as a sustainable alternative to fossil-based AA production.
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- 2021
8. Microbial electrochemical approaches of carbon dioxide utilization for biogas upgrading
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Yifeng Zhang, Deepak Pant, Xuyuan Chen, Suman Bajracharya, and Nabin Aryal
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Environmental Engineering ,Health, Toxicology and Mutagenesis ,Electromethanogens ,Methane ,chemistry.chemical_compound ,Bioreactors ,Biogas ,Environmental Chemistry ,Process engineering ,Resource recovery ,Bioelectrochemical system ,Electrode material ,business.industry ,Public Health, Environmental and Occupational Health ,In-situ ,General Medicine ,General Chemistry ,Continuous mode ,Carbon Dioxide ,Pollution ,chemistry ,CO2 reduction ,Biofuels ,Carbon dioxide ,Environmental science ,business ,Ex-situ ,Hydrogen ,Biomethane - Abstract
Microbial electrochemical approach is an emerging technology for biogas upgrading through carbon dioxide (CO2) reduction and biomethane (or value-added products) production. There are limited literature critically reviewing the latest scientific development on the Bioelectrochemical (BES) based biogas upgrading technology, including CO2 reduction efficiency, methane (CH4) yields, reactor operating conditions, and electrode material tested in BES reactor. This review analyzes the reported performance and identifies the crucial parameters to be considered for future optimization, which is currently missing. In this review, the performances of BES approach of biogas upgrading under various operating settings in particular fed-batch, continuous mode in connection to the microbial dynamics and cathode materials have been thoroughly scrutinized and discussed. Additionally, other versatile application options associated with BES based biogas upgrading, such as resource recovery, are presented. The three-dimensional electrode materials have shown superior performance in supplying the electrons for the reduction of CO2 to CH4. Most of the studies on the biogas upgrading process conclude hydrogen (H2) mediated electron transfer mechanism in BES biogas upgrading.
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- 2022
9. Technological progress and readiness level of microbial electrosynthesis and electrofermentation for carbon dioxide and organic wastes valorization
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Moumita Roy, Nabin Aryal, Yifeng Zhang, Sunil A. Patil, and Deepak Pant
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Chemistry (miscellaneous) ,Process Chemistry and Technology ,Management, Monitoring, Policy and Law ,Waste Management and Disposal ,Catalysis - Published
- 2022
10. Sustainable biowaste recycling using insects
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Pradip Adhikari, Anish Ghimire, Prabhat Khanal, and Nabin Aryal
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Solid waste management ,Human food ,Waste management ,Greenhouse gas ,fungi ,Biomass ,Environmental science ,Biodegradable waste ,Environmentally friendly - Abstract
Solid waste management is an important environmental and public health challenge, particularly in the developing world. This chapter highlights the importance of organic waste recycling using insects, which can subsequently be utilized as an alternative animal feed or even human food ingredient. In addition, biowaste conversion by exploiting insects is found to be environmentally more beneficial (reduced greenhouse gas emissions) than traditional waste handling, such as composting. Thus, organic waste valorization via insects could be a sustainable measure of biowaste treatment as it generates novel nutrient sources while posing a minimum threat to the environment. Characterizing biowaste as an insect rearing substrate, examining the potential role of the insect gut microbiota on waste degradability and insect biomass and quality, and identifying environmentally friendly residue handling approaches are some of the critical aspects for insect-based biowaste recycling in the future.
- Published
- 2021
11. Contributors
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Kaoutar Aboudi, Pradip Adhikari, Banafsha Ahmed, Carlos José Álvarez-Galleg, Brahim Arhoun, Nabin Aryal, Abdelkarim Aydi, Mohammed Bakraoui, Abdellatif Barakat, Elli Maria Barampouti, Hassan El Bari, Gabriel Capson-Tojo, Beatriz de Diego-Díaz, Brajesh Kumar Dubey, Doha Elalami, Renaud Escudié, Luis Alberto Fernández-Güelfo, Juana Fernández-Rodríguez, Pallavi Gahlot, Anish Ghimire, Yasser El Gnaoui, Cesar Gomez-Lahoz, Moktar Hamdi, Rattana Jariyaboon, N. Jawiarczyk, Teofil Jesionowski, Prasad Kaparaju, Fadoua Karouach, Abid Ali Khan, Prabhat Khanal, Sireethorn Khaonuan, Anwar Khursheed, Prawit Kongjan, Audrey Lallement, Maria Loizidou, Sofia Mai, Rachad El Mail, Dimitris Malamis, Rosa Marchetti, Oluchi Mbachu, Florian Monlau, Konstantinos Moustakas, H.M. Berdasco Muñoz, Long D. Nghiem, Luong Ngoc Nguyen, Sompong O-Thong, Debasree Purkayastha, Alissara Reungsang, Angel Robles, Luis Isidoro Romero-García, Faten Saidane, Sudipta Sarkar, Hari Bhakta Sharma, Jean-Philippe Steyer, Kine Svensson, M. Eugenia Tapia-Martín, Ahmed Tawfik, Vinay Kumar Tyagi, Nikannapas Usmanbaha, Jules B. van Lier, Ciro Vasmara, A. Medina Vaya, Saikrishna Venna, Raffaella Villa, Maria Villen-Guzman, Hang P. Vu, Kaouther Zaafouri, and Jakub Zdarta
- Published
- 2021
12. Bioelectrochemical systems for biogas upgrading and biomethane production
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Anders Bentien, Nabin Aryal, Lars Ditlev Mørck Ottosen, Deepak Pant, Michael Vedel Wegener Kofoed, Aryal, Nabin, Mørck Ottosen, Lars Ditlev, Vedel Wegener Kofoed, Michael, and Pant, Deepak
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Biogas ,business.industry ,Production (economics) ,Environmental science ,Electricity ,Continuous mode ,Laboratory scale ,Process engineering ,business ,Resource recovery - Abstract
Biogas upgrading by employment of bioelectrochemical systems (BESs) is an emerging approach for electricity-based production of biomethane. Recent advances within the field have successfully demonstrated BES for biogas upgrading at laboratory scale under different configurations and operating conditions: in situ, ex situ, batch mode, and continuous mode. This chapter summarizes the development and status of bioelectrochemical biogas upgrading, and includes examples of multifunctional systems combining biogas upgrading with resource recovery. Insights are given into proposed electron transfer mechanisms and reported BES designs for CO2 reduction to methane. BES technology for biogas upgrading has primarily been developed to lab-scale and still has to be further developed to evaluate the current economic perspectives of the technology compared to conventional biogas-upgrading technologies.
- Published
- 2021
13. List of contributors
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Saumya Ahlawat, Nabin Aryal, Prakash Aryal, Francisco Manuel Baena-Moreno, Anders Bentien, K.V. Christensen, Carlos Dinamarca, M. Errico, Lu Feng, Kazimierz Gaj, Luz M. Gallego, Vijay Kumar Garlapati, Anish Ghimire, Pooja Ghosh, Raju Gyawali, Moonmoon Hiloidhari, Mads Borgbjerg Jensen, Rimika Kapoor, Mehak Kaushal, Dilip Khatiwada, Michael Vedel Wegener Kofoed, Dhamodharan Kondusamy, Shilpi Kumari, Piet N.L. Lens, Sunil Prasad Lohani, S. Venkata Mohan, Henrik Bjarne Møller, Benito Navarrete, Anirudh Bhanu Teja Nelabhotla, Birgir Norddahl, Lars Ditlev Mørck Ottosen, Deepak Pant, Kamal K. Pant, Valerio Paolini, Grzegorz Pasternak, Francesco Petracchini, Ram Chandra Poudel, Karthik Rajendran, M.C. Roda-Serrat, Shivali Sahota, Manju Sapkota, Marco Segreto, Surajbhan Sevda, Goldy Shah, Swati Sharma, J. Shanthi Sravan, Athmakuri Tharak, Laura Tomassetti, Marco Torre, Patrizio Tratzi, Fernando Vega, Virendra Kumar Vijay, and Alastair James Ward
- Published
- 2021
14. Material-Microbes Interactions : Environmental Biotechnological Perspective
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Nabin Aryal, Yifeng Zhang, Sunil A. Patil, Deepak Pant, Nabin Aryal, Yifeng Zhang, Sunil A. Patil, and Deepak Pant
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- Microbiologically influenced corrosion, Materials--Microbiology
- Abstract
Material-Microbes Interactions: Environmental Biotechnological Perspective brings great insights into microbes-material interactions, biofilm formation and emerging bioprocesses within the field of applied biotechnology. The book systematically summarizes the fundamental principles, the state-of-the-art in microbes-material interaction, and its application in bioprocess and environmental technology development. Understanding the fundamental processes of biofilm formation, the role of material to exchange the energy with microbes, biofilm matrix, and optimization of the biofilm formation process is useful to everyone involved with bioprocess development. This book will be of significant interest to environmental technology developers, researchers, university professors, policymakers, graduate and postgraduate students and other stakeholders. Interestingly, academic institutions, wastewater treatment plants and research centers have upscaled biofilm-based environmental technologies, such as moving bed bioreactors, microalgae, tricking bed reactors, biofilters, and bioelectrochemical process as promising environmental technologies. Illustrates growing interest in biofilm-based technology development, either wastewater treatment using carrier materials or valorizing waste material into resources using biofilm-based bioprocess Focuses explicitly on the microbes-material interactions in various biotechnologies Covers a broad range of biofilm-based bioprocesses, including new and state-of-the-art options and trends within the field Includes photo-sets on biofilm development and bioreactor systems
- Published
- 2023
15. Coupling of microbial electrosynthesis with anaerobic digestion for waste valorization
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Suman Bajracharya, Nabin Aryal, and Nirmal Ghimire
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Anaerobic digestion ,chemistry.chemical_compound ,Biogas ,Chemistry ,Microbial electrosynthesis ,Degradation (geology) ,Biodegradable waste ,Bioprocess ,Pulp and paper industry ,Methane ,Resource recovery - Abstract
Anaerobic digestion (AD) has been widely applied bioprocess to produce the biogas for fuels from organic waste degradation. AD has been integrated with other processes for increasing the digestion efficiency and waste valorization. The integration of AD with other bioprocess optimizes the production of targeted product and reduces the waste. Recently, microbial electrosynthesis (MES) was coupled with AD for the biomethane production, chemical synthesis and resource recovery. MES coupling to AD also gives an opportunity for value-added chemical generation and hence provides additional economic gains of integrated system. In MES, the remaining carbon dioxide (CO2) in biogas is reduced to methane by methanogens utilizing in situ produced hydrogen at cathode, thereby enriching methane content. Furthermore, electroactive microbes could directly accept the electron from cathode to reduce the CO2 to methane and chemicals. Therefore, CO2 fraction in the biogas could be utilized for the further chemical synthesis such as acetate, butyrate. In this chapter, advances on AD technology and MES coupling with AD are thoroughly discussed for the production of fuels and chemicals. The outputs of recent laboratory scale experiments are summarized and discussed. Furthermore, mechanism of CO2 reduction is elaborated with methane and chemical production.
- Published
- 2020
16. Prime Techniques for Pre- and Post-Treatments of Anaerobic Effluents and Solids
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Jayesh M. Sonawane, Shalik Ram Sharma, Nabin Aryal, Suman Kharel, Suman Bajracharya, and Deepak Pant
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Soil conditioner ,Nutrient ,Anaerobic respiration ,business.industry ,Digestate ,Environmental science ,Fermentation ,Pulp and paper industry ,business ,Effluent ,Anaerobic exercise ,Renewable energy - Abstract
Several pre-treatment approaches have been explored to enhance the anaerobic fermentation kinetics and efficiency, which include thermal-alkaline treatment, free ammonia, sequential ultrasound techniques as well as grinding, and sieving. Additionally, valorization of mineralized compounds and production of reusable water can also be achieved via post-treatments. The post-treatment concept allows preserving or recovery of value-added byproducts in the form of manures, soil conditioners, and renewable energy. In this chapter, we explain the recent advancement in the pre-treatment and post-treatment of anaerobic digestate to enhance the anaerobic process and for the removal of undesirable compounds, recovery of energy, nutrients, and waste stabilization before disposal.
- Published
- 2020
17. Contributors
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Zularisam ab bin Wahid, Min Addy, Birgitte Ahring, Syeda Nazish Ali, Muhammad Naveed Anwar, Nabin Aryal, Dimitris Athanassiadis, Mukesh Kumar Awasthi, Ashutosh Awasthi, Sanjeev Kumar Awasthi, Mujtaba Baqar, Satya Sundar Bhattacharya, Nilutpal Bhuyan, Tuhin Kanti Biswas, Neonjyoti Bordoloi, Anuj Kumar Chandel, Ram Chandra Poudel, Hongyu Chen, Paul Chen, Yanling Cheng, Ravi Kumar Chhetri, Kirk Cobb, Subhasish Das, Silvio Silvério da Silva, Utsab Deb, Goldy De Bhowmick, Sarah de Souza Queiroz, Kuan Ding, Yumin Duan, Maria das Graças de Almeida Felipe, Tsai Garcia-Perez, Manuel Garcia-Perez, Bhabesh Gogoi, Lina Gogoi, Nirmali Gogoi, Linee Goswami, Reena Gupta, Indarchand Gupta, David J.I. Gustavsson, Prakash M. Halami, Aoxi He, Andrés Felipe Hernández-Pérez, Moonmoon Hiloidhari, Zhen Hu, Avinash P. Ingle, Dharana Jayant, Ratna Kalita, Dipanjan Kashyap, Rupam Kataki, P.C. Kesavan, Muhammad Usman Khan, Samir Kumar Khanal, Suman Kharel, Manish Kumar, Hanwu Lei, Tao Liu, Yuhuan Liu, Shiyu Liu, Paulo Ricardo Franco Marcelino, Sabrina Martiniano, Kristina Medhi, Arti Mishra, Puranjan Mishra, Santanu Mukherjee, Rumi Narzari, Tankeswar Nath, Hua Thai Nhan, Abdul Sattar Nizami, D.R. Palsaniya, Ashok Pandey, Deepak Pant, Peng Peng, Rafael R. Philippini, Shiv Prasad, Supriyanka Rana, Xiuna Ren, Roger Ruan, Saurabh Sarma, Ajit Kumar Sarmah, Jenna Senecal, Pradeep Kumar Sharma, Prithvi Simha, Kripal Singh, Rana Pratap Singh, Lakhveer Singh, M.S. Swaminathan, Mohammad J. Taherzadeh, S.K. Tewari, Indu Shekhar Thakur, Mats Tysklind, Venkata Krishna Kumar Upadhyayula, Fernanda Valadares, Björn Vinnerås, Quan Wang, Yunpu Wang, Sumeth Wongkiew, Dalia Yacout, Pooja Yadav, Zengqiang Zhang, Junchao Zhao, and Nan Zhou
- Published
- 2020
18. Agro-based industrial wastes as potent sources of alternative energy and organic fertilizers
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Ram Chandra Poudel, Ravi Kumar Chhetri, Deepak Pant, Nabin Aryal, and Suman Kharel
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Waste management ,Biosolids ,Agriculture ,business.industry ,Biofuel ,Bioenergy ,Biofertilizer ,Alternative energy ,Environmental science ,Environmental pollution ,Bagasse ,business - Abstract
Agriculture-based industries generate significant amounts and varieties of agro-industrial wastes (AIW). AIW, if not treated properly, may cause environmental pollution and pose a harmful effect on human and animal health. Although AIW consist of organic compounds that can pose a risk to the environment, however, if used in the right way can potentially produce bioenergy, biofertilizer, and biofuels. Energy generation using agro-wastes not only fulfill the energy demand locally but also contribute to a significant reduction in greenhouse gas emissions. Bioenergy a possible substitute for fossil-fuels can be generated from AIW residues like rice straw, sweet potato, sugarcane bagasse, sawdust, etc. Nutrient-rich and bioactive compounds obtained from AIW can be recycled as raw materials in the agro-based industries, which can reduce the total production costs. Moreover, agricultural wastes, such as animal manures, agricultural effluents, biosolids, etc., can be used as organic fertilizers. This will help to mitigate the scarcity of organic fertilizers and increase the crop yield and productivity. However, the sorption of heavy metals in fertilizers needs to be considered. AIW can be converted to biodegradable plastic or can be used as a feed-in aquaculture industry. Overall, AIW seems to be a potent source of alternative energy and organic fertilizers.
- Published
- 2020
19. Methane production from syngas using a trickle-bed reactor setup
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Michael Vedel Wegener Kofoed, Cecilie Bøgeholdt Petersen, Mikkel Odde, Lars Ditlev Mørck Ottosen, and Nabin Aryal
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0106 biological sciences ,Environmental Engineering ,Biomass ,Bioengineering ,010501 environmental sciences ,01 natural sciences ,Methane ,chemistry.chemical_compound ,Bioreactors ,Biogas ,Natural gas ,010608 biotechnology ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Sewage ,Renewable Energy, Sustainability and the Environment ,business.industry ,General Medicine ,Carbon Dioxide ,Trickle-bed reactor ,Pulp and paper industry ,chemistry ,Biofuel ,Biofuels ,Carbon dioxide ,Environmental science ,business ,Hydrogen ,Syngas - Abstract
Syngas from gasification of waste biomass is a mixture of carbon monoxide (CO), carbon dioxide (CO2), and hydrogen (H2), which can be utilized for the synthesis of biofuels such as methane (CH4). The aim of the study research work was to demonstrate how syngas could be methanated and upgraded to natural gas quality (biomethane) in a fed-batch trickle-bed reactor system using either manure – (AD-M) or sludge-based (AD-WW) inoculum as microbial basis. The methanated syngas had a high concentration of CO2 and did not fulfil the criteria for natural gas quality biomethane. Further upgrading of syngas to biomethane could be achieved simultaneously in the same reactors by addition of exogenous H2, resulting in CH4 concentrations up to 91.0 ± 3.5% (AD-WW) and 95.3 ± 1.0% (AD-M). Microbial analysis indicated that the communities differed between AD-M and AD-WW demonstrating functional redundancy among the microbial communities of different inocula.
- Published
- 2021
20. Emerging Technologies and Biological Systems for Biogas Upgrading
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Nabin Aryal, Lars Ditlev Morck Ottosen, Michael Vedel Wegener Kofoed, Deepak Pant, Nabin Aryal, Lars Ditlev Morck Ottosen, Michael Vedel Wegener Kofoed, and Deepak Pant
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- Biotechnology, Biogas industry--Technological innovations, Biogas
- Abstract
Emerging Technologies and Biological Systems for Biogas Upgrading systematically summarizes the fundamental principles and the state-of-the-art of biogas cleaning and upgrading technologies, with special emphasis on biological processes for carbon dioxide (CO2), hydrogen sulfide (H2S), siloxane, and hydrocarbon removal. After analyzing the global scenario of biogas production, upgrading and utilization, this book discusses the integration of methanation processes to power-to-gas systems for methane (CH4) production and physiochemical upgrading technologies, such as chemical absorption, water scrubbing, pressure swing adsorption and the use of membranes. It then explores more recent and sustainable upgrading technologies, such as photosynthetic processes using algae, hydrogen-mediated microbial techniques, electrochemical, bioelectrochemical, and cryogenic approaches. H2S removal with biofilters is also covered, as well as removal of siloxanes through polymerization, peroxidation, biological degradation and gas-liquid absorption. The authors also thoroughly consider issues of mass transfer limitation in biomethanation from waste gas, biogas upgrading and life cycle assessment of upgrading technologies, techno-economic aspects, challenges for upscaling, and future trends.Providing specific information on biogas upgrading technology, and focusing on the most recent developments, Emerging Technologies and Biological Systems for Biogas Upgrading is a unique resource for researchers, engineers, and graduate students in the field of biogas production and utilization, including waste-to-energy and power-to-gas. It is also useful for entrepreneurs, consultants, and decision-makers in governmental agencies in the fields of sustainable energy, environmental protection, greenhouse gas emissions and climate change, and strategic planning. Explores all major technologies for biogas upgrading through physiochemical, biological, and electrochemical processes Discusses CO2, H2S, and siloxane removal techniques Provides a systematical approach to discuss technologies, including challenges to gas–liquid mass transfer, life cycle assessment, technoeconomic implications, upscaling and systems integration
- Published
- 2021
21. Enhanced microbial electrosynthesis with three-dimensional graphene functionalized cathodes fabricated via solvothermal synthesis
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Qijin Chi, Pier-Luc Tremblay, Tian Zhang, Arnab Halder, and Nabin Aryal
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Materials science ,Graphene ,General Chemical Engineering ,Solvothermal synthesis ,Inorganic chemistry ,Microbial electrosynthesis ,02 engineering and technology ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,Sporomusa ovata ,Electrosynthesis ,01 natural sciences ,Cathode ,law.invention ,Bioelectrochemical reactor ,law ,Electrochemistry ,Cyclic voltammetry ,0210 nano-technology ,0105 earth and related environmental sciences - Abstract
The biological reduction of CO 2 into multicarbon chemicals can be driven by electrons derived from the cathode of a bioelectrochemical reactor via microbial electrosynthesis (MES). To increase MES productivity, conditions for optimal electron transfer between the cathode and the microbial catalyst must be implemented. Here, we report the development of a 3D-graphene functionalized carbon felt composite cathode enabling faster electron transfer to the microbial catalyst Sporomusa ovata in a MES reactor. Modification with 3D-graphene network increased the electrosynthesis rate of acetate from CO 2 by 6.8 fold. It also significantly improved biofilm density and current consumption. A 2-fold increase in specific surface area of the 3D-graphene/carbon felt composite cathode explained in part the formation of more substantial biofilms compared to untreated control. Furthermore, in cyclic voltammetry analysis, 3D-graphene/carbon felt composite cathode exhibited higher current response. The results indicate that the development of a 3D-network cathode is an effective approach to improve microbe-electrode interactions leading to productive MES systems.
- Published
- 2016
22. Increased carbon dioxide reduction to acetate in a microbial electrosynthesis reactor with a reduced graphene oxide-coated copper foam composite cathode
- Author
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Marc H. Overgaard, Yiming Chen, Lulu Wan, Adam Carsten Stoot, Pier-Luc Tremblay, Nabin Aryal, and Tian Zhang
- Subjects
medicine.medical_specialty ,Materials science ,Bioelectric Energy Sources ,Biophysics ,Oxide ,chemistry.chemical_element ,Biocompatible Materials ,02 engineering and technology ,Acetates ,Veillonellaceae ,Electrochemistry ,01 natural sciences ,law.invention ,chemistry.chemical_compound ,Bioreactors ,Bioelectrochemical reactor ,law ,Microbial electrosynthesis ,medicine ,Reduced graphene oxide ,Physical and Theoretical Chemistry ,Electrodes ,Graphene ,010401 analytical chemistry ,Electrochemical Techniques ,General Medicine ,Carbon Dioxide ,021001 nanoscience & nanotechnology ,Copper ,Cathode ,0104 chemical sciences ,chemistry ,Chemical engineering ,Biofilms ,Bioelectrochemistry ,Graphite ,0210 nano-technology ,Biocatalyst ,Oxidation-Reduction ,Copper foam - Abstract
Microbial electrosynthesis is a bioprocess where microbes reduce CO 2 into multicarbon chemicals with electrons derived from the cathode of a bioelectrochemical reactor. Developing a highly productive microbial electrosynthesis reactor requires excellent electrical connection between the electrochemical setup, the cathode, and the microbes. Copper is a highly conductive cathode material widely employed in electrochemical apparatuses. However, the antimicrobial properties of copper limit its usage for bioelectrochemistry. Here, biocompatible reduced graphene oxide coated on copper foam is synthesized as a cathode material for the microbial electrosynthesis of acetate from CO 2 . Dense and electroactive Sporomusa ovata biofilms form on the surface of reduced graphene oxide-coated copper foam electrodes while only scattered and damaged cells cover uncoated copper electrodes. Besides the formation of metabolically-active biofilms, acetate production rate from CO 2 is 21.3 and 43.5-fold higher with this novel composite cathode compared with an uncoated copper foam cathode and a reversed cathode made of reduced graphene oxide foam coated with copper, respectively. The results demonstrate that reduced graphene oxide can be employed as a biocompatible and conductive buffer between microbes and bactericidal electrode materials with excellent electrochemical property to enable highly performant microbial electrosynthesis.
- Published
- 2019
23. Bioelectrochemical Syntheses
- Author
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Suman Bajracharya, Nabin Aryal, Heleen De Wever, and Deepak Pant
- Published
- 2019
24. Methane loss from commercially operating biogas upgrading plants
- Author
-
Torben Kvist and Nabin Aryal
- Subjects
Technology ,020209 energy ,Scrubber ,Biogas ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Methane ,Membrane technology ,chemistry.chemical_compound ,Bioreactors ,Bioenergy ,0202 electrical engineering, electronic engineering, information engineering ,Thermal oxidizer ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Waste management ,business.industry ,Regenerative thermal oxidizer ,Renewable energy ,Anaerobic digestion ,chemistry ,Biofuels ,Biogas upgrading ,Environmental science ,business ,Methane loss - Abstract
Biogas technology is one of the widely applied anaerobic digestion approaches to harvest methane from different wastes. Recently, methane loss from biogas plants and its environmental and economic consequences have been underlined, but not thoroughly researched. In this investigation, process related CH 4 loss from nine different commercially operating biogas upgrading plants such as water scrubber, amine, and membrane-based plants was examined. The result of the measurements showed an average of 0.81% methane loss with respect to supplied methane to the upgrading plants. A methane loss up to 1.97% was detected in water scrubber methane upgrading technology and up to 0.56% loss from membrane technology, while 0.04% methane loss was detected in amine based upgrading, thus the water scrubber has shown the most detrimental effect as regards methane loss. The regenerative thermal oxidizer was further applied to reduce CH 4 emission by 99.5% of the amount of CH 4 in the waste gas from the upgrading unit, which ensures the sustainable process of biogas production.
- Published
- 2019
25. Conductive material engineered direct interspecies electron transfer (DIET) in anaerobic digestion: Mechanism and application
- Author
-
Anwar Khursheed, Vinay Kumar Tyagi, Satya Brat Tiwari, Banafsha Ahmed, Pallavi Gahlot, Nabin Aryal, and Absar Ahmad Kazmi
- Subjects
0106 biological sciences ,biology ,Chemistry ,Methanogenesis ,Microorganism ,Soil Science ,Plant Science ,010501 environmental sciences ,biology.organism_classification ,01 natural sciences ,Redox ,Anaerobic digestion ,Electron transfer ,Syntrophy ,Chemical engineering ,010608 biotechnology ,Bacteria ,0105 earth and related environmental sciences ,General Environmental Science ,Archaea - Abstract
Biological syntrophy can be defined as a nutritional condition where various syntrophic microorganisms mutually synergize their metabolic activities to break down complex organic substrates that cannot be otherwise catabolized by either individually. Direct interspecies electrons transfer (DIET) is a syntrophic metabolism wherein free electrons flow from one cell to another through shared physical, electrical connections without the requirement of reduced electron carriers (redox mediators) like molecular hydrogen or formate or protein released after cell death. In anaerobic digestion (AD), the transfer of electrons between two different syntrophic microbial communities such as bacteria and archaea is a vital process for methanogens to get control of energy barriers and catabolize complex organics which could not be digested by them alone. Studies conducted so far show that DIET can be accelerated by conductive materials like carbon nanotubes, biochar, carbon cloth, granular activated carbon (GAC), and magnetite. The conductive materials mediated DIET has showed to be highly efficient in enhancement of methane yield than indirect interspecies electron transfer (IIET) in case of conventional anaerobic digestion (AD) process. This review summarizes the studies conducted to date on the effect of conductive materials mediated DIET on methanogenesis in the AD. The different types and concentrations of conducting materials affecting (a) DIET, (b) major microbial communities required for carrying out DIET, and (c) the rate of methanation, are critically discussed in the review.
- Published
- 2020
26. Syngas production using straw pellet gasification in fluidized bed allothermal reactor under different temperature conditions
- Author
-
Niels B.K. Rasmussen and Nabin Aryal
- Subjects
Materials science ,020209 energy ,General Chemical Engineering ,Energy Engineering and Power Technology ,02 engineering and technology ,Raw material ,020401 chemical engineering ,Pellet ,0202 electrical engineering, electronic engineering, information engineering ,0204 chemical engineering ,Resource recovery ,Fouling ,Wood gas generator ,Olivine ,Organic Chemistry ,Straw ,Syngas ,Pulp and paper industry ,Wood ,Fuel Technology ,Allothermal ,Fluidized bed ,Tar ,Gasification - Abstract
Straw is one of the most available agriculture waste materials to be utilized as resource. Straw gasification for syngas production is one of the alternatives for resource recovery. Nevertheless, straw gasification might be problematic due to high alkali content, which may cause fouling of the gasifier reactor. In the present study, straw was gasified at different temperatures; in particular 750 °C, 800 °C, 850 °C, 900 °C, and 950 °C furnace temperature, was evaluated and then compared with wood feedstock using allothermal gasifier. The tested temperatures are not the limiting factor for the wood gasification using olivine (Mg2+,Fe2+)2SiO4 bed material and catalysis. Relatively, lower temperature is appropriate for straw gasification where agglomeration with bed material was observed at a higher temperature.
- Published
- 2020
27. Process Related Methane Loss from Commercially Operating Biogas-Upgrading Plants
- Author
-
Torben Kvist and Nabin Aryal
- Abstract
Biogas technology is one of the widely applied anaerobic digestion approaches to harvest methane from different wastes such as wastewater treatment sludge, agriculture residue, and other biomasses. Biogas can be further purified utilizing biogas upgrading technology so it can be applied as biomethane in vehicles and for gas grid injection. Recently, methane loss from biogas plants and its environmental and economic consequences have been underlined, but not thoroughly researched. In this investigation, process related CH4 loss from nine different commercially operating biogas upgrading plants such aswater scrubber, amine, and membrane-based plants was examined. The result of the measurements showed an average of 0.7% methane loss with respect to supplied methane to the upgrading plants. A methane loss up to 1.7% has been detected in water scrubber methane upgrading technology, while 0.037 % methane loss was detected in amine based upgrading, thus the water scrubber has shown the most detrimental effect as regards methane loss. Finally, the regenerative thermal oxidizer was further applied to reduce CH4 emission by 99.5 % of the amount of CH4 in the waste gas from the upgrading unit.
- Published
- 2018
28. An overview of microbial biogas enrichment
- Author
-
Lars Ditlev Mørck Ottosen, Nabin Aryal, Fariza Ammam, Deepak Pant, and Torben Kvist
- Subjects
Environmental Engineering ,Waste management ,Renewable Energy, Sustainability and the Environment ,020209 energy ,Bioengineering ,02 engineering and technology ,General Medicine ,010501 environmental sciences ,01 natural sciences ,Archaea ,Bioreactors ,Biogas ,Methanation ,Biofuels ,0202 electrical engineering, electronic engineering, information engineering ,Bioreactor ,Environmental science ,Waste Management and Disposal ,Methane ,0105 earth and related environmental sciences ,Hydrogen - Abstract
Biogas upgrading technologies have received widespread attention recently and are researched extensively. Microbial biogas upgrading (biomethanation) relies on the microbial performance in enriched H2 and CO2 environments. In this review, recent developments and applications of CH4 enrichment in microbial methanation processes are systematically reviewed. During biological methanation, either H2 can be injected directly inside the anaerobic digester to enrich CH4 by a consortium of mixed microbial species or H2 can be injected into a separate bioreactor, where CO2 contained in biogas is coupled with H2 and converted to CH4, or a combination hereof. The available microbial technologies based on hydrogen-mediated CH4 enrichment, in particular ex-situ, in-situ and bioelectrochemical, are compared and discussed. Moreover, gas-liquid mass transfer limitations, and dynamics of bacteria-archaea interactions shift after H2 injection are thoroughly discussed. Finally, the summary of existing demonstration, pilot plants and commercial CH4 enrichment plants based on microbial biomethanation are critically reviewed.
- Published
- 2018
29. An overview of cathode materials for microbial electrosynthesis of chemicals from carbon dioxide
- Author
-
Deepak Pant, Nabin Aryal, Fariza Ammam, and Sunil A. Patil
- Subjects
Electrode material ,Materials science ,Hydrogen ,Microbial electrosynthesis ,chemistry.chemical_element ,Biomass ,Nanotechnology ,02 engineering and technology ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,01 natural sciences ,Pollution ,Cathode ,Catalysis ,law.invention ,chemistry.chemical_compound ,chemistry ,law ,Carbon dioxide ,Environmental Chemistry ,Surface modification ,0210 nano-technology ,0105 earth and related environmental sciences - Abstract
The applicability of microbial electrosynthesis (MES) for chemical synthesis from carbon dioxide (CO2) requires improved production and energetic efficiencies. Microbial catalysts, electrode materials, and reactor design are the key components which influence the functioning of such processes. In particular, cathode materials critically impact the electricity-driven CO2 reduction process by microorganisms. Interest in cathode surface modifications for improving MES processes is thus consistently increasing. In this paper, the recent developments and spatial modification of cathode materials for microbial CO2 reduction are systematically reviewed. The characteristics of commercially available materials, their modifications, and developments in new materials that have been used as cathodes for MES are summarized. Key cathode–microorganism interactions that led to improved CO2 conversion are then discussed. The cathode surface modification approaches have focused mainly on improving the surface area and surface chemistry of the materials. Although the modified cathode surfaces improved biofilm growth in direct electron uptake based bioconversions, they have achieved lower acetate production rates than that of hydrogen-based MES processes thus far. Research efforts on different materials suggest that the three-dimensional cathodes that can retain more biomass, in particular in hydrogen-based bioconversions, are promising for further improvements in production efficiencies. Further efforts toward reducing the energy inputs for achieving energetically efficient MES processes by using electrocatalytically efficient cathodes are needed.
- Published
- 2017
30. Freestanding and flexible graphene papers as bioelectrochemical cathode for selective and efficient CO2 conversion
- Author
-
Pier-Luc Tremblay, Patrick Rebsdorf Whelan, Minwei Zhang, Tian Zhang, Nabin Aryal, Qijin Chi, and Arnab Halder
- Subjects
Materials science ,Standard hydrogen electrode ,Scanning electron microscope ,Science ,02 engineering and technology ,010501 environmental sciences ,Electrocatalyst ,Bioinformatics ,Biosynthesis ,Industrial microbiology ,01 natural sciences ,law.invention ,Applied microbiology ,Carbon capture and storage ,law ,0105 earth and related environmental sciences ,Multidisciplinary ,Graphene ,Microbial electrosynthesis ,021001 nanoscience & nanotechnology ,Cathode ,Chemical engineering ,Electrode ,Medicine ,0210 nano-technology ,Electrocatalysis ,Faraday efficiency - Abstract
During microbial electrosynthesis (MES) driven CO2 reduction, cathode plays a vital role by donating electrons to microbe. Here, we exploited the advantage of reduced graphene oxide (RGO) paper as novel cathode material to enhance electron transfer between the cathode and microbe, which in turn facilitated CO2 reduction. The acetate production rate of Sporomusa ovata-driven MES reactors was 168.5 ± 22.4 mmol m−2 d−1 with RGO paper cathodes poised at −690 mV versus standard hydrogen electrode. This rate was approximately 8 fold faster than for carbon paper electrodes of the same dimension. The current density with RGO paper cathodes of 2580 ± 540 mA m−2 was increased 7 fold compared to carbon paper cathodes. This also corresponded to a better cathodic current response on their cyclic voltammetric curves. The coulombic efficiency for the electrons conversion into acetate was 90.7 ± 9.3% with RGO paper cathodes and 83.8 ± 4.2% with carbon paper cathodes, respectively. Furthermore, more intensive cell attachment was observed on RGO paper electrodes than on carbon paper electrodes with confocal laser scanning microscopy and scanning electron microscopy. These results highlight the potential of RGO paper as a promising cathode for MES from CO2.
- Published
- 2017
31. Performance of different Sporomusa species for the microbial electrosynthesis of acetate from carbon dioxide
- Author
-
Pier-Luc Tremblay, Dawid Mariusz Lizak, Tian Zhang, and Nabin Aryal
- Subjects
Environmental Engineering ,Sporomusa aerivorans ,Bioengineering ,02 engineering and technology ,010501 environmental sciences ,Acetates ,Veillonellaceae ,Sporomusa ovata ,01 natural sciences ,Sporomusa ,Catalysis ,chemistry.chemical_compound ,Electron transfer ,Organic chemistry ,Waste Management and Disposal ,Electrodes ,0105 earth and related environmental sciences ,High rate ,biology ,Renewable Energy, Sustainability and the Environment ,Microbial electrosynthesis ,General Medicine ,Carbon Dioxide ,021001 nanoscience & nanotechnology ,biology.organism_classification ,chemistry ,Carbon dioxide ,0210 nano-technology ,Oxidation-Reduction - Abstract
Sporomusa ovata DSM-2662 produces high rate of acetate during microbial electrosynthesis (MES) by reducing CO 2 with electrons coming from a cathode. Here, we investigated other Sporomusa for MES with cathode potential set at −690 mV vs SHE to establish if this capacity is conserved among this genus and to identify more performant strains. S. ovata DSM-2663 produced acetate 1.8-fold faster than S. ovata DSM-2662. On the contrary, S. ovata DSM-3300 was 2.7-fold slower whereas Sporomusa aerivorans had no MES activity. These results indicate that MES performance varies among Sporomusa . During MES, electron transfer from cathode to microbes often occurs via H 2 . To establish if efficient coupling between H 2 oxidation and CO 2 reduction may explain why specific acetogens are more productive MES catalysts, the metabolisms of the investigated Sporomusa were characterized under H 2 :CO 2 . Results suggest that other phenotypic traits besides the capacity to oxidize H 2 efficiently are involved.
- Published
- 2017
32. Effect of Hg, As and Pb on biomass production, photosynthetic rate, nutrients uptake and phytochelatin induction in Pfaffia glomerata
- Author
-
B. H. N. Razafindrabe, Maria Rosa Chitolina Schetinger, Fernando Teixeira Nicoloso, Nabin Aryal, H. G. Huang, Dharmendra K. Gupta, Masahiro Inouhe, Júlia Gomes Farias, and Tingqiang Li
- Subjects
Chlorophyll ,Health, Toxicology and Mutagenesis ,Management, Monitoring, Policy and Law ,Toxicology ,Photosynthesis ,Metal ,Nutrient ,Dry weight ,Metals, Heavy ,Toxicity Tests ,Botany ,Phytochelatins ,Biomass ,Amaranthaceae ,biology ,Chemistry ,General Medicine ,Pfaffia glomerata ,biology.organism_classification ,Carotenoids ,visual_art ,Shoot ,visual_art.visual_art_medium ,Metalloid ,Phytochelatin - Abstract
Plantlets of Pfaffia glomerata (Spreng.) were exposed for 28 days to three different metal/metalloid (Hg, Pb and As) with different levels (Hg 1; As 25, 50, 100 and Pb 100 and 400 μM) to analyze the possible phytochelatin initiation and affects on growth and photosynthetic pigments vis-à-vis metal accumulation potential of plants. The plantlets showed significant Hg, As and Pb accumulation in roots (150, 1267.67 and 2129 μg g(-1) DW respectively); however, a low root to shoot metal translocation was observed. It was interesting to note that all tested macronutrient (Mg, K, Ca) was higher in shoots and just opposite in case of micronutrients (Cu, Fe, Zn), was recorded highest in roots. The growth of plantlets (analyzed in terms of length and dry weight) was negatively affected by various metal treatments. In addition, the level of photosynthetic pigments alters significantly in response to all metal/metalloid treatment. In response to all tested metal/metalloids in plants only As induced phytochelatins (PC2, PC3 and PC4) in roots, and in shoots, GSH was observed in all tested metal/metalloids. In conclusion, P. glomerata plantlets could not cooperatively induce phytochelatins under any of Hg and Pb levels.
- Published
- 2013
33. Bioelectrocatalyzed reduction of acetic and butyric acids via direct electron transfer using a mixed culture of sulfate-reducers drives electrosynthesis of alcohols and acetone
- Author
-
Nabin Aryal, Deepak Pant, Banwari Lal, Mohita Sharma, Xochitl Dominguez Benetton, Karolien Vanbroekhoven, and Priyangshu M. Sarma
- Subjects
Acetates ,Electrosynthesis ,Catalysis ,Butyric acid ,Acetone ,Electron Transport ,chemistry.chemical_compound ,Electron transfer ,Mixed culture ,Materials Chemistry ,Organic chemistry ,Sulfate ,biology ,Bacteria ,Metals and Alloys ,General Chemistry ,Electrochemical Techniques ,biology.organism_classification ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Butyrates ,chemistry ,Alcohols ,Ceramics and Composites ,Biocatalysis ,Oxidation-Reduction - Abstract
Sulfate-reducing bacteria (SRB) developed biocathodes efficient for reduction of acetic and butyric acids to alcohols and acetone via direct electron transfer reaching current densities of 160-210 A m(-2).
- Published
- 2013
34. Final FutureGas report
- Author
-
Marie Münster, Poul Erik Morthorst, Morten Stryg, Nabin Aryal, Michael Vedel Wegener Kofoed, Torben Kvist Jensen, Erik Ahlgren, Stefanie Buchholz, and David Pisinger
35. Techno-economic assessment of biomethane production from syngas derived from biomass gasifier
- Author
-
Sahraro, Milad, Aryal, Nabin, Øi, Lars Erik, Supervisor, Nabin Aryal, Co-Supervisor, and Lars Erik Øi
- Abstract
Biomethane is one of the renewable fuels widely utilized for various purposes, including transportation, heating, and power production. Growing interest is currently seen in this biofuel production utilizing waste material such as agricultural residual, sludge and municipal solid waste in anaerobic digestion. However, there is a limitation in using entire organic biomass in anaerobic digestion due to lignocellulose mass and fibrous material, which is hard to digest by microbes. Thus, gasification could be a supplementary technology to utilize residual, digested, and contaminated waste. The coupling of gasification and anaerobic digestion has been tested in lab scale reactor to valorize the waste as biofuel. However, techno-economic evaluation is essential to upscale the technology. Thus, this master's thesis aimed to perform the techno-economic of coupling gasifier and anaerobic digestion to utilize syngas for biomethane production. Three potential scenarios were evaluated for their techno-economic viability. Scenario 1 is based on biomethane generation through syngas fermentation coupled with gasification. Combination of hydrothermal gasification, syngas fermentation, and a steam addition as a hydrogen source make up Scenario 2. In scenario 3, an electrolytic unit was added instead of steam (in scenario 2) as a hydrogen source to produce biomethane. The scenarios' efficiencies range from 13% to 35%. The maximum energy efficiency, 35%, was found in Scenario 3. Furthermore, scenario 1 (237 NOK per litre) was followed by scenario 2 (164 NOK per litre) and scenario 3 (120 NOK per litre) as the scenarios in which the minimum selling price of biomethane decreased. Due to its undiscounted net present value of 76 million NOK compared to the other scenarios, scenario 3 is the most profitable based on the discounted cash flow analysis results. According to sensitivity analysis, the cost of labour and utility had the most impact on the minimum selling price of biomethane.
- Published
- 2023
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