Pyrolysis and combustion kinetics of Sida cordifolia L. using thermogravimetric analysis

Sida cordifolia L.: Ethnobotany, Phytochemistry, Phytonanotechnology, and Commercial Application

BACKGROUND

After a period of prolonged indifference, where synthetic drugs were preferred, interest in the biological aspects and bioactive ingredients of plants accountable for therapeutic potential has been explored eminently. Sida cordifolia L. is a perennial herb that has been widely utilized in Indian (Ayurveda, Unani, and Siddha), American, and Chinese folk medicine and herbalism practice for curing a wide range of ailments in human beings.

OBJECTIVES

The goal of this review is to elucidate indigenous knowledge parallelly with the pharmacotherapeutics potential of Sida cordifolia L. against various diseases. It is also intended to display pertinent information related to nanoparticle profiling.

METHODS

In the current comprehensive study, web-based searches were performed by using several databases, such as Google Scholar, PubMed, ResearchGate, Science Direct, and Scopus, to figure out relevant research work and data published in academic journals from 1930 to July, 2023 using single or combination of keywords listed herewith.

RESULTS

More than 50 chemical constituents, including quinazoline and phenethylamine alkaloids, flavones, flavonol, phytosterol, fatty acids, etc., were reported to be found in different parts of healthy plants. Apart from traditional claims and pharmacological aspects, several marketed herbal formulations and granted patents were also described.

CONCLUSION

Several in-vitro and in-vivo studies validated the usage of S. cordifolia as antiinflammatory, antibacterial, antifungal, antiprotozoal, anthelmintic, anticancer, antiulcer, cardioprotective, hypoglycemic, etc. agent. Few patents are also related to S. cordifolia, and more research work needs to be carried out for its potential granted to use as an antiviral agent and other new drug discovery molecules.

Kinetics of maize cob and bean straw pyrolysis and combustion

Kinetic studies are important for the design and optimisation of thermochemical processes. This study involved analysis of the pyrolysis and combustion behaviour of the agricultural residues (bean straw and maize cob) by non-isothermal thermogravimetric analysis. Increasing the heating rate from 10 to 40 K min^-1 during both combustion and pyrolysis increased the degradation rate of both feedstocks and the gaseous yields of H₂O, CO and CO₂. The activation energies determined by the Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose methods varied which reveals that the pyrolysis and combustion of these agricultural residues are complex processes involving multiple reactions. The average activation energy of maize cob and bean straw were 214.15 and 252.09 kJ mol^-1 for pyrolysis and 202.26 and 165.64 kJ mol^-1 for combustion, respectively. The order of reaction ranged between 9.0-10.3 and 6.3-13.3 for both feedstocks in combustion and inert environments, respectively. Modelled data is important to enable the optimisation of reactor design for pyrolysis and combustion for energy generation from agricultural residues.

Densification of Yak Manure Biofuel Pellets and Evaluation of Parameters: Effects on Properties

This study was first conducted to comprehensively investigate the potential of yak manure as a raw material to prepare fuel pellets. The effect of different parameters such as binder, pressure, and moisture content on pellet density and diametric compressing strength was investigated using a laboratory single pelleting press unit. Results showed that increasing the pressure can help to obtain high-quality fuel pellets. The pellet properties (density and diametric compressing strength) initially increased and then decreased with moisture content increase. By contrast, binder was not identified to promote density and diametric compressing strength. The parameters were optimized using the response surface method with central composite design to obtain high-quality pellets. In conclusion, the use of yak manure as a raw material to make fuels can be considered a sustainable approach and can effectively be used to fulfill the energy and heating requirements of rural areas.

Thermogravimetric analysis of the pyrolysis and combustion kinetics of surface dead combustibles in the Daxing'an Mountains

In boreal regions, the frequency of forest fires is increasing. In this study, thermogravimetric analysis was used to analyze the pyrolysis kinetics of dead surface combustibles in different forest types within the Daxing'an Mountains, China. The results show that the combustible material load of forest types, the Larix forest (LG) is relatively high. Base on the E of kinetic parameters, the LG, and Quercus forest (QM) forest types had relatively high combustibility values and comprehensive combustibility values for 1-, 10-, and 100-h time lags. According to the obtained P values, the pyrolysis of dead surface fuels with 1-, 10-, and 100-h time lags is relatively difficult in the Larix / Betula mixed forest (L-B) and QM forest types. Therefore, mixed forests of the LG, L-B, and QM tree species can be established as fire-resistant forests to establish a fire barrier, reduce the combustibility of forest stands, and reduce the possibility of forest fires.

Pyrolysis of almond (Prunus amygdalus) shells: Kinetic analysis, modelling, energy assessment and technical feasibility studies

The aim of this work was to study the thermogravimetric analysis through the pyrolysis of almond (Prunus amygdalus) shells for evaluating its potential for bioenergy at different heating rates (10, 25, and 50 K min^-1). The activation energy values for the process were of the range of 153.0, 152.02, and 152.73 kJ mol^-1 as calculated by Kissenger-Akahira-Sunrose (KAS), Ozawa-Flynn-Wall (OFW) and Starink models respectively. The change in the Gibbs free energy was ~181 kJ mol^-1. Diffusion-based reaction, followed by the chemical reaction mechanism,was dominant thermal degradation as envisaged by the Coats-Redfern method. The validation of the experiments was accomplished through the artificial neural network, reiterating its further usage in any conversional studies of biomass. A difference of < 10 kJ mol^-1 between the values of activation energy and enthalpy of the degradation reaction indicated favourable product formation. The results offer potential application of almond shells for energy production through pyrolysis.

Study of Combustion Characteristics and Kinetics of Agriculture Briquette Using Thermogravimetric Analysis

The present paper was aimed to investigate the physicochemical properties and combustion characteristics of corn straw briquette as a fuel energy. The results of physicochemical properties displayed that corn straw briquette has higher volatile matter, lower ash content, and higher heating value. Combustion characteristics and kinetic analysis were investigated using thermogravimetry analysis at various heating rates of 10, 15, and 20 °C/min. It was observed that the maximum burning rate shifted to a higher temperature as the heating rate increased. In addition, a lower heating rate would help in better heat transfer, leading to less mass residual. In contrast, the combustion characteristic index showed a nearly 2-fold increase under a higher heating rate, indicating a good combustion performance. The combustion kinetics were expressed using isoconversional methods with Kissinger-Akahira-Sunose and Ozawa-Flynn-Wall methods, which authenticated the average activation energy at 108.85 and 114.42 kJ/mol, respectively. These results can provide a theoretical basis and data support for further utilization of agriculture biomass briquette.

Thermogravimetric Analysis of Solid Biofuels with Additive under Air Atmosphere

The paper presents the combustion profile of selected fuels as a result of thermogravimetric analysis. The main purpose of this study was to investigate a mixture of different types of fuel and the influence of the use of a fuel additive on the combustion process profile. As a fuel additive, halloysite was used to investigate the thermogravimetric profiles. It was confirmed that the main combustion parameters such as ignition temperature, burnout temperature, and maximum peak temperature correlated accordingly with different combustibility indices such as the ignition index, the burnout index, and the combustion indices. Furthermore, the present study provided a comparison of selected methods for analyzing non-isothermal solid-state kinetic data and investigated the kinetics of thermal decomposition to describe the ongoing process. Two non-isothermal model methods (Kissinger and Ozawa) were used to calculate the Arrhenius parameters. The effect of heating rate and the addition of halloysite as a fuel additive on decomposition were studied.