Article
Chemistry, Analytical
Chengkun Zhang, Long Han, Mi Yan, Jia Xia, Nai Rong, Humair Ahmed Baloch, Hui Guo, Pingjiang Wu, Guoqiang Xu, Kaili Ma
Summary: This study investigated the hydrothermal co-liquefaction of rice straw and waste cooking-oil model compound to optimize bio-crude yield. The results showed that the highest biocrude yield was obtained at specific temperature, time and mass ratios, and the presence of WCOM improved the overall conversion rate of RS. Co-liquefaction was found effective in enhancing the qualitative and quantitative features of biomass products.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2021)
Article
Environmental Sciences
Songqi Leng, Huiting Jiao, Tonggui Liu, Wei Pan, Jiefeng Chen, Jie Chen, Huajun Huang, Haoyi Peng, Zhibin Wu, Lijian Leng, Wenguang Zhou
Summary: Co-liquefaction combined with hydrothermal liquefaction (HTL) aqueous phase (AP) recirculation can improve the practicality of the HTL process. It was found that different compounds were formed during the co-liquefaction and recirculation, which led to changes in the yield and chemical properties of the bio-crude and hydrochar.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Thermodynamics
Roya Hamidi, Lingyu Tai, Laura Paglia, Marco Scarsella, Martina Damizia, Paolo De Filippis, Sogand Musivand, Benedetta de Caprariis
Summary: In this study, a low-cost catalyst and heterogeneous hydrogen producer were used for the upgrading of bio-crude. The synthesized Y zeolite showed better performance due to the introduction of TMAOH template. The upgraded oil yield increased and the coke amount reduced, leading to a higher heating value. Hydrogenation products were produced in higher amounts, consuming furan derivatives and lignin-derived compounds. Additionally, a one-pot catalytic hydrothermal treatment method was conducted, combining the bio-crude production and upgrading steps together.
ENERGY CONVERSION AND MANAGEMENT
(2022)
Article
Thermodynamics
A. Yerrayya, A. Nikunj, P. Francis Prashanth, S. R. Chakravarthy, Upendra Natarajan, R. Vinu
Summary: Hydrothermal liquefaction of bagasse was conducted in this study to maximize the yield of bio-crude and its higher heating value. The optimal conditions were obtained and the major organic constituents in the bio-crude were identified. The process showed positive energy gain and favorable sustainability metrics.
Article
Energy & Fuels
Shengfei Dong, Xinghua Huang, Xiaoyi Yang
Summary: This paper investigates the effect of different conditions on microalgae bio-crude enhancement, and finds that under specific conditions, using ethanol-water co-solvent or methanol/ethanol-water co-solvent as the medium can achieve high recovery rates of carbon, hydrogen, and energy, as well as high content of fatty acids and fatty acid esters. The nitrogen content of bio-crude obtained by the two-step method is lower, and ethanol-water co-solvent as the liquid phase medium performs well in terms of the content of cholesterol and vitamin E as bioactive substances.
Article
Energy & Fuels
Swathi Bhat, Venu Babu Borugadda, Ajay K. Dalai
Summary: The study discussed the potential of preparing emulsions by mixing bio-crude and light cycle oil as fuel for diesel engines, investigated the appropriate parameters for emulsification, and obtained improved physicochemical properties compared to using bio-crude alone. The properties of the emulsion were found to closely match ASTM D 6751-09 biodiesel specifications.
Article
Chemistry, Multidisciplinary
Shuo Dai, Yao Fu, Peng He, Li Mu, Pengfei Liu, Yuyan Zhang
Summary: Corn straw-based graphitized carbon was synthesized using carbonization and catalyzed graphitization with corn straw as the raw material and catalytic liquefaction technology. A mixture of polyethylene glycol (PEG200) and glycerol in a mass ratio of 7:3 was used as the liquefied agent, and hydroxydiethylidene glycolic acid was employed as the liquefied catalyst. The graphitized carbon exhibited improved graphitization, a lamellar microstructure, and reduced defects when carbonized at 600 degrees C, graphitized at 850 degrees C, and using ferric acetylacetonate as the catalyst at a concentration of 7.0 mmol g(-1). The yield of corn straw-based graphitized carbon reached 22.20%.
Article
Energy & Fuels
Jiashun Hu, Xuanying Chen, Xiaoxue Yang, Ruosong Li, Le Wu
Summary: As bio-energy is the only carbon-containing renewable energy source, its development and utilization are crucial to addressing the energy crisis and the greenhouse effect. In order to reduce the production cost of bio-fuels, bio-oil derived from biomass and algae can be co-processed with vacuum gas oil in an existing catalytic cracking unit, resulting in the production of gasoline and diesel products with renewable carbon. Techno-economic analysis revealed that the co-processing scenario involving hydrothermal liquefaction provided a clear economic advantage.
Article
Agricultural Engineering
S. Harisankar, P. Francis Prashanth, Jeganathan Nallasivam, R. Vishnu Mohan, R. Vinu
Summary: Aqueous phase recirculation reduces bio-crude yield but increases bio-char yield, while improving the carbon and hydrogen content of the products. In addition to indicating the dominance of dehydrogenation reactions, AP recirculation also leads to better performance and ion accumulation characteristics in bio-char.
BIORESOURCE TECHNOLOGY
(2021)
Article
Agricultural Engineering
S. Harisankar, R. Vishnu Mohan, Vaishali Choudhary, R. Vinu
Summary: This study focuses on the hydrothermal liquefaction (HTL) and carbonization (HTC) of rice straw using water from various sources. The results show that industrial wastewater yields the highest bio-crude production, while seawater yields the highest hydrochar production.
BIORESOURCE TECHNOLOGY
(2022)
Article
Energy & Fuels
Yijing Wu, Xin Xu, Xuanjing Jiang, Jingying Lin, Xiaoyu Lin, Shicheng Zhao, Jie Yang
Summary: This study extracted water-soluble polysaccharide from excessive growth of Enteromorpha prolifera (EP) and utilized residual EP to generate crude bio-oil using hydrothermal liquefaction (HTL). The study found optimal conditions for polysaccharide extraction and successfully co-liquefied residual EP with microalgae. The valorisation route developed in this study is important for full utilization of EP and improving its economic viability and sustainability.
Article
Chemistry, Analytical
Benedetta de Caprariis, Marco Scarsella, Irene Bavasso, M. Paola Bracciale, Lingyu Tai, Paolo De Filippis
Summary: Understanding the behavior of cellulose in hydrothermal conditions with the assistance of different transition metals is crucial for comprehending the lignocellulosic biomass liquefaction mechanism. The addition of Ni, Fe, and Zn during hydrothermal liquefaction of cellulose showed varying effects on bio-crude yield and quality. Fe was found to be the most effective in increasing bio-crude yield and higher heating value, while Zn led to an increase in water-soluble products.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2021)
Article
Engineering, Chemical
Ikram Eladnani, Maria Paola Bracciale, Martina Damizia, Seyedmohammad Mousavi, Paolo De Filippis, Rajae Lakhmiri, Benedetta de Caprariis
Summary: The study investigated the catalytic hydrothermal liquefaction of Brachychiton populneus biomass seed, using Ni and Fe as catalysts. The highest bio-crude yields were achieved at 330 degrees C and 10 min of reaction time, with Ni/Al2O3 as catalyst and Fe as hydrogen donor. The combination of Fe and Ni/Al2O3 favored the conversion of fatty acids into hydrocarbons, increasing their amount in the bio-crude to approximately 20%.
Article
Green & Sustainable Science & Technology
Gurpreet Kaur Nagi, Mayurika Goel, Rahul Tiwari, Suchitra Bhawna, Suchitra Gaur, Nirupama Mallick, Shovon Mandal
Summary: This research aims to demonstrate the feasibility of producing bio-crude bio-oil and high-value products from microalgae using a circular biorefinery process. By cultivating marine microalgae Nannochloropsis oceanica and extracting carotenoids using supercritical carbon dioxide extraction, the study shows that bio-crude oil can be obtained from the residual biomass through hydrothermal liquefaction. The research highlights the potential of circular bioeconomy and biorefinery practices in developing sustainable and environmentally friendly solutions for the chemical and energy sectors.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Energy & Fuels
Snunkhaem Echaroj, Nattadon Pannucharoenwong, Hwai Chyuan Ong, Phadungsak Rattanadecho
Summary: The research investigated the parameters for supercritical ethanol liquefaction of rice straw over sulfated graphene oxide. Results showed that reaction temperature, sulfuric acid concentration, and catalyst amount significantly affected the production and quality of biofuel, with a decrease in biofuel production when sulfuric acid concentration exceeded 6M.
Article
Energy & Fuels
Sumit Chaturvedi, Shiv Vendra Singh, V. C. Dhyani, K. Govindaraju, R. Vinu, S. Mandal
Summary: This study characterized and pyrolyzed seven biomasses of Indian origin to produce biochars. The biochars were thoroughly characterized to assess their potential applications in energy, environment, and agriculture. Different biochars showed distinct properties, with some suitable for soil amelioration and others suitable for renewable solid fuel purposes.
BIOMASS CONVERSION AND BIOREFINERY
(2023)
Article
Agricultural Engineering
Janaki Komandur, R. Vinu, Kaustubha Mohanty
Summary: The present study investigates the pyrolysis process of Mesua ferrea L, a non-edible oilseed, to understand the composition of pyrolysate and the thermal degradation behavior of biomass. The study confirms that valuable chemicals can be obtained from Mesua ferrea L through pyrolysis.
BIORESOURCE TECHNOLOGY
(2022)
Article
Agricultural Engineering
S. Harisankar, R. Vishnu Mohan, Vaishali Choudhary, R. Vinu
Summary: This study focuses on the hydrothermal liquefaction (HTL) and carbonization (HTC) of rice straw using water from various sources. The results show that industrial wastewater yields the highest bio-crude production, while seawater yields the highest hydrochar production.
BIORESOURCE TECHNOLOGY
(2022)
Article
Thermodynamics
A. Yerrayya, A. Nikunj, P. Francis Prashanth, S. R. Chakravarthy, Upendra Natarajan, R. Vinu
Summary: Hydrothermal liquefaction of bagasse was conducted in this study to maximize the yield of bio-crude and its higher heating value. The optimal conditions were obtained and the major organic constituents in the bio-crude were identified. The process showed positive energy gain and favorable sustainability metrics.
Article
Chemistry, Multidisciplinary
Yerrayya Attada, Vijay K. Velisoju, Hend Omar Mohamed, Adrian Ramirez, Pedro Castano
Summary: This study investigates the structure-function relationship of Cu-Ga/CeO2-ZrO2 catalysts through experiments and theoretical calculations, revealing the most balanced Cu-Ga interphase and specific mechanistic pathways for the reaction. The highest selectivity of the desired products is achieved when the amounts of Cu and Ga are equal. Comparing with other Ga-promoting systems, it is demonstrated that Cu achieves better balance.
JOURNAL OF CO2 UTILIZATION
(2022)
Article
Chemistry, Applied
Vallabh S. Prabhudesai, R. Vinu
Summary: Bifunctional catalysts containing metal and acid sites are commonly used for the hydrodeoxygenation (HDO) of bio-oil/bio-oil model compounds. Platinum group metals, such as Pt, Pd, and Ru, have shown high HDO activity due to their excellent hydrogenation character. In this study, Pt/AC demonstrated superior HDO activity compared to Pd/AC and Ru/AC, thanks to the existence of metallic Pt-0 on AC. Additionally, the presence of acid sites offered by HZSM-5 in physically mixed Pt/AC and HZSM-5 catalysts enhanced the selectivity towards propyl cyclohexane (PC) during HDO of isoeugenol.
TOPICS IN CATALYSIS
(2023)
Article
Chemistry, Physical
Idoia Hita, Hend Omar Mohamed, Yerrayya Attada, Naydu Zambrano, Wen Zhang, Adrian Ramirez, Pedro Castano
Summary: We analyze the evolution of coke species on Ni/ZSM-5, beta, and Y zeolites during ethylene oligomerization using high-resolution mass spectrometry. By directly analyzing the used catalysts and their soluble and insoluble coke fractions, we establish a correlation between reaction mechanisms, location of coke, and catalyst performance. Ab initio calculations are performed to understand the preferred location of coke. We investigate the peculiar deactivation mechanism of ZSM-5 zeolite (MFI structure) with two parallel deactivation pathways.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Energy & Fuels
B. Rajasekhar Reddy, Soham Sarkar, R. Vinu
Summary: Microwave-assisted pyrolysis of cylindrical woodblocks was studied to investigate the effects of microwave distribution, microwave power, and final temperature on product yields and bio-oil composition. It was found that microwave pyrolysis of woodblocks can be achieved without adding any external microwave absorber. Non-uniform pyrolysis occurred in a domestic microwave oven, while uniform pyrolysis was observed in a research-grade microwave reactor equipped with an antenna. High reaction temperatures were achieved with low microwave powers, indicating effective conversion of microwave energy to heat by the woodblocks. The yields of bio-oil, bio-char, and gases remained consistent at different microwave powers and reaction temperatures. However, low microwave power and 600 degrees C resulted in low yields of non-condensable gas and high yield of biochar. The composition of bio-oil was sensitive to the operating conditions, and high selectivity to total phenolics was achieved at specific microwave power and temperature. CO2 and CO were the major non-condensable gases, while H-2 was also produced. High energy recovery in bio-char was observed, suggesting its potential as a feedstock for gasification.
BIOMASS CONVERSION AND BIOREFINERY
(2023)
Article
Energy & Fuels
R. Bharathi Raja, Anusha C. Halageri, R. Sankar, Ramanujam Sarathi, Ravikrishnan Vinu
Summary: This study investigates the use of non-thermal plasma in a swirl-induced electrode discharge reactor for the dry reforming of methane. The reactor design promotes better mixing of reactant gases, leading to increased conversion rates. The study examines the effect of flow rates and compositions of CO2/CH4 on conversion, and analyzes the characteristics of the produced syngas and solid carbon. The findings show that higher concentrations of CO2 or CH4 result in increased conversion, while increasing flow rates reduce energy costs.
Article
Energy & Fuels
S. Harisankar, R. Vinu
Summary: Hydrothermal liquefaction (HTL) is a promising technology that converts waste biomass into valuable chemicals and energy through physical and chemical transformations under sub-critical or supercritical water conditions. Most existing studies have focused on the conversion of specific feedstocks like wood, algae, and plastics, with limited research on the HTL of heterogeneous feedstocks like municipal solid wastes (MSW). This paper reviews the available literature on HTL of biodegradable wastes, non-biodegradable polymers, and MSW, as well as the challenges and possibilities of scaling up the HTL process with MSW as the feedstock.
Article
Chemistry, Physical
Xueli Yao, Qingpeng Cheng, Yerrayya Attada, Samy Ould-Chikh, Adrian Ramirez, Xueqin Bai, Hend Omar Mohamed, Guanxing Li, Genrikh Shterk, Lirong Zheng, Jorge Gascon, Yu Han, Osman M. Bakr, Pedro Castano
Summary: The dry reforming of methane achieves sustainability goals by activating carbon dioxide and producing syngas. The catalyst plays a crucial role in controlling the process's activity, selectivity, and stability. A one-step reduction strategy is used to assemble a catalyst with uniform-sized Ni-Fe alloy nanoparticles. The catalyst shows exceptional stability and inhibits coke formation.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Chemistry, Physical
Madambakam Midhun Kumar, Vallabh S. Prabhudesai, Ravikrishnan Vinu
Summary: This study evaluated the catalytic activities of Pd-Lewis acid metal oxides supported on commercial activated carbon (AC) and activated biochar (ABC) for the selective production of monomeric phenols from alkali lignin through transfer hydrogenolysis. The results showed that the AC-supported catalysts had larger Pd crystallite size and better degree of graphitization, while ABC-supported catalysts exhibited higher dimerization of monomeric phenols.
MOLECULAR CATALYSIS
(2023)
Article
Chemistry, Physical
S. Harisankar, Ravikrishnan Vinu
Summary: Black liquor, a by-product from the paper and pulp industry, can be valorized through hydrothermal liquefaction (HTL) for the production of bioproducts and biochemicals. In this study, HTL experiments were conducted on hardwood black liquor to evaluate the effects of temperature, biomass loading, and residence time. The results showed that temperature had a significant effect on product yield and selectivity, while biomass loading mainly impacted the yield of hydrochar. Phenols, aliphatic hydrocarbons, and ketones were the major organic compounds detected in the liquid product.
SUSTAINABLE ENERGY & FUELS
(2023)
Article
Chemistry, Physical
Vallabh S. Prabhudesai, K. Saravanakumar, Lakshmiprasad Gurrala, R. Vinu
Summary: Lignin-first depolymerization using reductive catalytic fractionation is a potential strategy for resource recovery in biorefinery. Wood delignification is achieved using low-metal catalysts supported on activated charcoal. Pd/ACC catalyst shows the highest degree of delignification and selectivity towards lignin monomers. Ultrasonic pre-treatment enhances the delignification and selectivity, achieving high retention of carbohydrates. Pd/ACC catalyst demonstrates superior activity due to better dispersion and hydrogenation activity of Pd.
SUSTAINABLE ENERGY & FUELS
(2023)
Review
Energy & Fuels
Arputhasamy Joseph Amalanathan, Ramanujam Sarathi, Maciej Zdanowski, Ravikrishnan Vinu, Zbigniew Nadolny
Summary: This paper reviews the gassing tendency of different insulating fluids in transformers and provides precautionary measures for fault diagnosis. Experimental techniques for identifying gassing due to electrical and thermal stress, as well as stray gassing phenomenon, are explained. Interpretation schemes based on historical data of mineral oil may lead to unexpected errors for alternative fluids. Mineral oil and natural ester have positive gassing tendency, while synthetic ester exhibits negative gassing tendency. Stray gases are mostly caused by C-C bond breakage at normal operating temperature. Hydrogen and ethylene are predominantly formed at lower temperatures. Silicone oil and ester fluids are more stable and produce less gassing compared to mineral oil under simulated hot spots. Additives, oxygen, and water content in insulating fluids can confuse the identification of actual faults. Regeneration of insulating fluids using adsorbents reduces gassing tendency depending on the number of cycles.