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This study evaluates the pyrolysis kinetics and resource recovery potential from mixtures of bamboo sawdust (BS) biomass, and a COVID-19 waste material, body coverall (BC). The pyrolysis kinetics of BS, BC and their binary mixtures was modeled using distributed activation energy modeling approach. BS pyrolysis was described using three pseudocomponents, viz., cellulose, hemicellulose and lignin, and BC using two pseudocomponents, polypropylene and an additive. For pyrolysis of individual BS and BC, the activation energy was highest for lignin (272.1 kJ mol−1) and the additive (321.7 kJ mol−1) pseudocomponent. The activation energy (240.7 kJ mol−1) and change in enthalpy (234.9 kJ mol−1) were found to be the lowest for lignin for the blend BS:BC (3:1 wt/wt). Analytical pyrolysis revealed alkenes (63.3%) and oxygen containing aromatics (57.4%) as the major compounds from BC and BS, respectively. Cyclic alcohols were the major compounds from pyrolysis of BS–BC mixtures. This study demonstrates that blending BC with BS lowers the energy barrier for pyrolysis to generate valuable chemicals. [Display omitted] [ABSTRACT FROM AUTHOR]

Conversion of wastes to energy and other value-added products is considered as a suitable method towards energy security. Wastes from various sources are becoming potential feedstocks for energy production through different techniques. The economy and sustainability of these processes demand the use of low-cost catalysts. Red mud (RM) is one of the most abundantly produced industrial wastes from aluminum industries. Such a huge production of RM, its alkaline nature and the presence of a small quantity of radioactive elements make it an environmental liability. Out of various utilization methods, RM as a catalyst for different chemical processes has been very successful. Presence of many valuable metals in RM, in particular, Fe makes it a suitable catalyst for energy production through processes such as pyrolysis, hydrotreating, transesterification and H 2 production from biomass and other sources. This article critically reviews the advances in sustainable energy production through different processes mentioned above by RM based catalysts. Different characterization, activation and stability study of RM along with outcomes and mechanism of these processes are discussed. Furthermore, drawbacks associated with the low catalytic activity of RM and works that need to be carried out in the future for the improvement of its catalytic activity are discussed in detail. Image 101037 • Recent development in catalytic utilization of red mud for energy synthesis were explored. • Physical and chemical properties of RM were briefly explained. • Pyrolysis, hydrodeoxygenation, H 2 production and transesterification were discussed. • Catalytic activity and reaction pathways of energy synthesis were proposed. • Perspective to enhance the activity of RM for energy production were proposed. [ABSTRACT FROM AUTHOR]

In the present study, the effect of biomass bed thickness and distance between successive beds on pyrolytic products yield were carried out. Sawdust of pine wood and sal wood, as well as husk of areca nut, were used as a biomass feedstock. To achieve maximum liquid yield, 500 °C temperature, 80 °C min−1 heating rate, 0.5 mm particle size and 100 mL min−1 gas flow rate was selected as optimum conditions. An equal amount of biomass was placed in six different bed arrangements while dividing the amount of biomass equally among the number of beds as well as keeping an equal distance between the successive beds. Further, the entire reactor was fitted inside the furnace so as to distribute the heat uniformly throughout the rector which also signified that each biomass bed has the same thermal profile at any time. It was found that liquid properties were better (lower viscosity, higher heating value) at fourth bed arrangement than in other bed arrangements. FTIR and GC-MS analysis confirmed the presence of aromatic, phenol, ester, ether, alcohol, acid, and amide groups. Gas chromatography also confirmed that with increasing temperature, the amount of hydrogen and hydrocarbons increased significantly while the formation of CO 2 was reduced. Image 1 • Effect of bed height and thickness on biomass pyrolytic products yields were studied. • Temperature, heating rate and particle size were optimized. • Optimization of bed arrangements resulted in higher and better liquid. • Complete characterization of pyrolytic oil was carried out. • Amounts of H 2 , HCs increased with increase in temperature whereas CO 2 reduced. [ABSTRACT FROM AUTHOR]

Abstract: This work reports the kinetic study of the pyrolysis of four non-edible oil seeds such as Mahua, Karanja, Niger and Linseed conducted at a heating rate of 5, 10 and 15 °C min−1 under nitrogen atmosphere. The relation between kinetic parameters and degradation rate was observed with respect to temperature and heating rate. The results indicated that the kinetic parameters were very close to each other and directly proportional to temperature and heating rate. The comparison of kinetic parameters related to heating rate concluded that heating rate had a direct affinity towards activation energy and pre-exponential factor. The TG-DTG analysis indicated three stages of thermal degradation during pyrolysis of the oil seeds whereas DSC analysis point towards the endothermic and exothermic pathway of pyrolysis. The presence of hemicelluloses, cellulose and lignin was determined on the basis of degradation temperature and their respective functional groups in the seeds observed by FTIR analysis. [Copyright &y& Elsevier]

Kinetic triplets and thermodynamic parameters of the pyrolysis of Putranjiva roxburghii (PR) and Cassia fistula (CF) non-edible oilseeds were studied using thermogravimetric analyzer. The kinetic parameters were assessed using both model-free [Kissinger-Akahira-Sunose (KAS), Flynn-Wall-Ozawa (OFW), Starink (STR), Li and Tang (LTA), Friedman (FRM), Vyazovkin (VYZ), Kissinger (KN), Avrami (AVM), and Master plot (MP)] and model-fitting [Coats-Redfern (CR)] methods at four different heating rates (10, 25, 40, and 55 °C/min) somewhere in the range of 10% and 80% conversions. The reaction mechanisms were found to be in good agreement with the experimental thermal analysis data. Thermodynamic parameters (ΔG, ΔH, and ΔS) are also determined by model-free isoconversional method. The kinetic and thermodynamic parameters recommended the appropriateness of PR and CF non-edible oilseeds for pyrolysis process. Image 1 • 1st study concerning the pyrolysis kinetics of putranjiva and amaltas non-edible oilseeds. • Both model-free and model-fitting methods were used. • Non-edible oilseeds pyrolysis model is discriminated by the master-plot method. • Non-edible oilseeds pyrolysis were well represented by A n and R n mechanism. [ABSTRACT FROM AUTHOR]

In the current investigation, a four stroke, variable speed, single cylinder, variable compression ratio (VCR) SI engine is operated with raw biogas at wide open throttle (WOT) condition and at five different CRs ranging from CR 10 to CR 14 over the operating speed range of the engine. The ignition timing (IT) of the engine is also varied from 23○CA to 47○CA before top dead centre (bTDC) at each operating CR. The optimized operating CR and IT of the engine are obtained through series of experiments and its effects on the performance, combustion and emission characteristic are analysed herein. The rise in operating CR from CR 10 to CR 12 enhanced the power output and efficiency of the biogas fueled SI engine by 12.72% and 5.68%, respectively and reduced fuel consumption by 5.42% at 1400 rpm. Enhancing the CR from CR 10 to CR 12, limited the intensification of NO x and unburnt hydrocarbon emission by 10.17% and 15.6%, respectively at 1400 rpm. Hence, CR 12 is recommended as the optimum CR and its combination with 1400 rpm and WOT setting is recommended as the best operating condition of the engine. • Raw biogas is successfully utilized as a standalone fuel in a variable speed SI engine. • Optimum CR and IT are attained through experiments for the engine operation. • At the optimum MBT timing, enhancement in torque is noticed when engine operates at optimum CR. • Maximum BP and BTE are higher for the lowest operating speed and optimum CR combination. • NO x and unburnt HC emissions intensify when engine operates with best CR and speed combination. [ABSTRACT FROM AUTHOR]

In this work, potato and sweet lime peels otherwise considered as waste were used as substrates for producing glucose. Different pre-treatment processes were carried out and the best conditions yielding higher amount of glucose concentration were further hydrolysed by enzyme. The pre-treated extract at 80 min in case of dilute acid hydrolysis with autoclaving conditions gave higher glucose concentration amongst all the pre-treatment processes for both the peels and hence considered for further analysis. Rationale for the next step of the experiment was designed based on a central composite statistical design (CCD). To obtain high glucose yield, response surface methodology (RSM) was used to optimize the hydrolysis conditions. The three parameters chosen for the study were; time (h), temperature (oC) and the rotation frequency of the incubator (revolutions per minute i.e. RPM). The optimum conditions in case of potato peel were found to be 56 h, 68 °C and 144 RPM and in case of sweet lime peel, 56 h, 68 °C and 167 RPM. Under these conditions, 46.17 (±0.77) gL−1 and 35.90 (±0.43) gL−1 of glucose were obtained for potato and sweet lime peels respectively. The optimum factors acquired from the statistical model were further confirmed using the experimental results. Image 1 • Various pre-treatment methods followed by enzymatic hydrolysis were carried out. • RSM was adopted as the statistical tool for optimization. • Optimum conditions for potato and sweet lime peels were found out. • Glucose obtained, potato peel: 46.17(±0.77) g L−1; sweet lime peel: 35.25 (±0.43) g L−1. [ABSTRACT FROM AUTHOR]

Abstract The main objective of the study is to explore the potential of raw biogas as an alternative and standalone fuel for gasoline fueled spark ignition (SI) engine. In the current investigation, a single cylinder, spark ignition engine is operated both with gasoline and raw biogas at a compression ratio of 10 under wide open and part throttle conditions. The baseline test is performed with gasoline and subsequent experiments are carried out with raw biogas. The engine performance, combustion and emission parameters are measured over a range of speed variations (1450–1700 rpm). Comparative analysis of the result showed 18% of reduction in brake power, 66% of increase in brake specific fuel consumption and 12% of reduction in break thermal efficiency when the engine is fueled with raw biogas. Because of the non-uniformity in the amount of supplied air and fuel to the engine in every cycle, the coefficient of variation of indicative mean effective pressure and peak pressure (COV pp and COV IMEP) are seen to be higher for biogas. The emission components such as CO and NO x are significantly reduced by 40% and 81.5%, respectively, while, the unburnt hydrocarbon (UHC) and CO 2 emission were increased by 6.8% and 40%, respectively. Highlights • Gasoline fueled SI engine is successfully modified to operate by pure raw biogas. • Performance of raw biogas fueled engine was compared with gasoline fueled engine. • Unique fuel induction methodology restricted the engine to derate beyond 18% at WOT condition. • Average NOx and CO emission of the raw biogas engine was reduced substantially. [ABSTRACT FROM AUTHOR]

A significant comparative study was done on thermal and catalytic pyrolysis of sawdust via metal-induced active site NiO and Ni (II) aluminates composite catalyst by integrating sawdust into a fixed-bed reactor and assessing product profile distribution from a temperature range of 773–873 K at 30 K min−1 heating rate under nitrogen purge gas (300 mL min−1). With an increase in temperature from 773 to 873 K, bio-oil yield was increased with a decrease in the yield of biochar. From thermal bio-oil characterization, it was observed that d -Allose was the prominent compound along with Beta- d -Glucopyranose-1,6-Anhydro with a remarkable C p value of 2.0 Jg-1 K−1 and an ignition temperature of 397.95 K. Catalytic upgradation of bio-oil using 10 % and 20 % catalyst resulted in phosphonic acid, (p-hydroxyphenyl)- and 6-Hepten-3-one, 5-Hydroxy-4-Methyl- as the candidate compounds with slightly decreased C p values of 0.095 Jg-1 K−1 and 0.826 Jg-1 K−1 respectively due to catalytic tar cracking of polyaromatic hydrocarbons present in the bio-oil. Biochar revealed amorphous graphitic multilayer nanosheets with polycrystalline and hexagonal crystal systems of the lattice structure with the presence of aromatic ring structures and –CN stretching as evident from FTIR analysis. [ABSTRACT FROM AUTHOR]