Thermocatalytic Pyrolysis of Waste Areca Nut into Renewable Fuel and Value-Added Chemicals.

Pyrolytic oil is currently in its early stages of production and distribution but has the potential to grow into a significant renewable energy source. It may be processed into a variety of useful substances, including chemicals, and used for heating, transportation, and energy production. The present investigation involves the production and characterization of pyrolytic oil from areca nut husk (ANH), with and without ZSM-5. The pyrolysis experiment was conducted in a semibatch tubular reactor at 600 °C and a heating rate of 80 °C min-1 using ZSM-5 at 20 wt %. The pyrolytic oil was examined via elemental analysis, viscosity, density, moisture content, GC-MS, FTIR, higher heating value (HHV), and ash content. The analysis of kinetics verified that the activation energy rises in proportion to the conversion rate. Additionally, employing ZSM-5 in catalytic pyrolysis at 20 wt % boosted the yield of pyrolytic oil by 11% compared to thermal pyrolysis. Employing ZSM-5 at 20 wt % resulted in a decrease in viscosity, oxygen content, and density by approximately 43.40 cSt, 15.20%, and 168 MJ kg-1, respectively. Moreover, it led to an increase in higher heating value (HHV) and carbon content by 11.71 MJ kg1- and 14.06%, respectively. An FTIR study of pyrolytic oil revealed the occurrence of hydrocarbons, aromatics, phenols, alcohols, and oxygenated chemicals. Moreover, GC-MS analysis indicated a significant increase in hydrocarbons (10.31%) and a decrease in phenols (2.36%), acids (6.38%), and oxygenated compounds with the introduction of the catalyst. Consequently, it can be inferred that utilizing ZSM-5 at 20 wt % during the pyrolysis of ANH aids in enhancing both the yield and characteristics of the resulting pyrolysis oil.

Green Synthesis of Reduced Graphene Oxide Using the Tinospora cordifolia Plant Extract: Exploring Its Potential for Methylene Blue Dye Degradation and Antibacterial Activity.

Graphene has attracted significant attention recently due to its unique mechanical, electrical, thermal, and optical properties. The present study focuses on synthesizing green rGO using the Tinospora cordifolia plant extract by mixing it in a suspension of graphene oxide. The plant extract of T. cordifolia acts as a reducing agent and is cost-effective, renewable, and eco-friendly. Green-synthesized rGO (G-rGO) was characterized using FTIR, HR-SEM, EDX, and HR-XRD analyses. G-rGO consists of nanosheets with an average width of approximately 30 nm. G-rGO has a range of hydrodynamic radius (270-470) nm and an average ζ potential of -29.9 mV. Further, G-rGO was used as a nanoadsorbent for optimal exclusion of methylene blue (MB) dye using the response surface methodology (RSM). Adsorption results confirmed 94.85% MB dye removal with 58.81 mg g-1 adsorption capacity at optimum conditions. The G-rGO's antibacterial activity was also tested against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) bacteria, finding the exhibited zone of inhibition of 10, 11, and 15 mm and 10, 13, and 17 mm at 20, 40, and 80 µg mL-1 concentrations of G-rGO, respectively.

A review of the next-generation biochar production from waste biomass for material applications.

The development of carbonaceous materials such as biochar has triggered a hot spot in materials application. Carbon material derived from biomass could be a vital platform for energy storage and conversion. Biochar-based materials deliver a novel approach to deal with the current energy-related challenges. To design and utilize the maximum potential of biochar for environmentally sustainable applications, it is crucial to understand the recent progress and advancement in molecular structures of biochar to discover a new possible field to simplify structural application networks. However, most of the studies demonstrated the application of biochar in the form of soil enhancers and bio-adsorbents, reducing soil emissions of greenhouse gases and as fertilizers. The present review on biochar highlighted the application of biochar-based materials in various energy storage and conversion sectors, comprising different types of conversion technologies, biochar formation mechanisms, modification techniques on biochar surface chemistry and its functionality, catalysts, biochar application in energy storage gadgets such as supercapacitors and nanotubes, bio-based composite materials and inorganic based composites materials. Finally, this review addressed some vital outlooks on the prospect of the functionalization and best utilization of biochar-supported materials in numerous energy storage and conversion fields. After reviewing the literature, it was directed that advanced and in-depth research is essential for structural analysis and separation, considering the macroscopic and microscopic evidence of the formed structural design of biochar for specific applications.

Catalytic pyrolysis of biomass over zeolites for bio-oil and chemical production: A review on their structure, porosity and acidity co-relation.

The oxygenated compounds found in bio-oil limit their application as a transportation fuel. Several studies were reported on eliminating the oxygenated components from bio-oil so as to improve its fuel properties. This work is dedicated to studying the shape selectivity, porosity, structure, acidity of zeolites and their effect in bio-oil and chemicals production. The unified pore size, specific structure, controlled Si/Al ratio, unique channels and circular entrances, mesoporosity, and acidity are the utmost discerning parameters for aromatics production and deoxygenation reaction. The conversion of biomass-derived oxygenates to aromatics using zeolite is subjected to the reactants entering the pore, conversion inside the pore, and diffusing out of the products from the zeolite pores. These approaches were considered for an in-depth understanding of zeolite properties, which will enhance the fundamental understanding of pyrolysis.

Value-Added Bio-carbon Production through the Slow Pyrolysis of Waste Bio-oil: Fundamental Studies on Their Structure-Property-Processing Co-relation.

The present work addresses the transformation of bio-oil into valuable biocarbon through slow pyrolysis. The biocarbons produced at three different temperatures (400, 600, and 900 °C), 10 °C min-1 heating rate, and 30 min holding time were tested for their surface morphology, thermal stability, elemental composition, functionality, particle size, and thermal and electrical conductivity. The physicochemical study of bio-oil showed substantial carbon content, higher heating value, and lower nitrogen content. Also, the Thermogravimetric analyzer-FourierTransform Infrared Spectroscopy (TGA-FTIR) study of bio-oil confirmed that the majority of gases released were hydrocarbons, carbonyl products, ethers, CO, and CO2, with a minor percentage of water and alcohol. Overall, it was found that the pyrolysis temperature has the dominant role in the yield and properties of biocarbon. The physicochemical characterization of biocarbon showed that the higher temperature based pyrolyzed biocarbon (600 and 900 °C) improved the properties in terms of thermal stability, thermal conductivity, graphitic content, ash content, and carbon content. Furthermore, the elemental and Energy-Dispersive Spectroscopy study of biocarbon confirmed the substantial depletion in oxygen and hydrogen at a higher temperature (600 and 900 °C) than the lower temperature based pyrolyzed biocarbon (400 °C). Additionally, the purest form of the biocarbon is found at a higher temperature (900 °C) with higher thermal stability and carbon content. The study of the surface morphology of biocarbon revealed that the higher temperature (600 and 900 °C) biocarbon showed larger and harder particles than the lower temperature biocarbon (400 °C); however, the electrical conductivity of biocarbon decreased, whereas thermal conductivity increased, with an increase in the pyrolysis temperatures. Moreover, the particle size analysis of biocarbon confirmed that most of the particles were found in the range of 1 µm. The increased thermal stability, carbon content, and graphitic content and the lower ash content endorse biocarbon as an excellent feedstock for carbon-based energy storage materials.

Kinetic analysis and pyrolysis behaviour of waste biomass towards its bioenergy potential.

The present study addressed the kinetics characteristics and pyrolysis behaviour of waste biomass Azadirachta indica (NM) and Phyllanthus emblica kernel (AM) in a thermogravimetric analyzer. Six model-free techniques such as Kissinger-Akahira-Sunose, Distributed Activation Energy Model, Friedman, Coats-Redfern, Ozawa-Flynn-Wall, Vyazovkin and Criado method were employed to evaluate the kinetic parameters at five varying heating rates (10-50 °C min-1). The physicochemical inspection directed that both the biomass had excellent prospects to produce energy and finest chemicals. FTIR study pointed strong evidence of moisture, protein, acid, and aromatics. The average apparent activation energy was found to be 176.66, 193.67, 196.06, 177.32 and 204.23 kJ mol-1 for NM and 184.77, 195.10, 189.95, 186.46, 184.57 kJ mol-1 for AM for KAS, OFW, FM, DAEM and VZ respectively. Further, master plot and thermodynamic study of AM and NM revealed that pyrolysis went through various reaction mechanisms at the time of pyrolysis.

Pyrolysis kinetics and synergistic effect in co-pyrolysis of Samanea saman seeds and polyethylene terephthalate using thermogravimetric analyser.

This work deals with co-pyrolysis of polyethylene terephthalate (PET) with Samanea saman seeds (SS) to understand the kinetics and synergistic effects between two different feedstocks. SS and PET were blended in different ratios (1:1, 3:1 and 5:1) and iso-conversional models such as Kissinger-Akahira-Sunose (KAS), Friedman method (FM), Starink (ST), Ozawa-Flynn-Wall method (OFW), and Coats-Redfern method (CR) were used to calculate the kinetic parameters. Results substantiate assumed hypothesis that blending of SS and PET at 3:1 provided higher synergistic effect and RMS value, which in turn indicated maximum formation of hot volatiles during pyrolysis. Kinetic analysis confirmed that individual SS and PET required higher activation energy while blended SS and PET at 3:1 ratio required lower activation energy to start the reaction. The thermodynamic and kinetic analysis confirmed that biomass had complex reaction kinetics which depends on reaction rate as well as its order.

Conversion of waste biomass and waste nitrile gloves into renewable fuel.

The present study deals co-pyrolysis of neem seeds (NM) and waste nitrile gloves (WNG) in a semi-batch reactor with and without catalysts. Results confirmed that the yield of pyrolytic liquid was higher (43.52 wt% at NM: WNG ratio of 3:1) during thermal co-pyrolysis compared to that of catalytic co-pyrolysis (40.42 wt% and 37.14 wt% respectively with CaO and Al2O3 as catalysts). The use of catalysts increased the carbon content, acidity, and heating value and reduced the oxygen content, viscosity, and density of the pyrolytic oil. FTIR analysis suggested the presence of useful functional groups while 1H NMR analysis confirmed high amounts of paraffin and aromatic compounds in the pyrolytic oil. GC-MS analysis of pyrolytic oil confirmed that blending of NM + WNG and use of catalysts reduced the oxygenated compounds and increased the alcohol and aldehyde thereby enhancing the fuel properties.

Pyrolysis kinetics and thermal behavior of waste sawdust biomass using thermogravimetric analysis.

The present study reports pyrolysis behavior of three waste biomass using thermogravimetric analysis to determine kinetic parameters at five different heating rates. Physiochemical characterization confirmed that these biomass have the potential for fuel and energy production. Pyrolysis experiments were carried out at five different heating rates (5-25 °C min-1). Five model-free methods such as Kissinger-Akahira-Sunose (KAS), Ozawa-Flynn-Wall (OFW), Friedman, Coats-Redfern, and distributed activation energy (DAEM) were used to calculate the kinetic parameters. The activation energy was found to be 171.66 kJ mol-1, 148.44 kJ mol-1, and 171.24 kJ mol-1 from KAS model; 179.29 kJ mol-1, 156.58 kJ mol-1, and 179.47 kJ mol-1 from OFW model; 168.58 kJ mol-1, 181.53 kJ mol-1, and 184.61 kJ mol-1 from Friedman model; and 206.62 kJ mol-1, 171.63 kJ mol-1, and 160.45 kJ mol-1 from DAEM model for PW, SW, AN biomass respectively. The calculated kinetic parameters are in good agreement with other reported biomass.