Thermocatalytic pyrolysis of agriculture waste biomass for the production of renewable fuels and chemicals

ABSTRACT The present work highlights the thermocatalytic pyrolysis of three different waste biomasses (Groundnut Stalk, Indian Rosewood, and Rice Straw) using meso and microporous catalysts for the effective conversion to fuels and chemicals. Thermocatalytic pyrolysis was found to be highly significant under optimum conditions (Temperature = 500°C, Heating rate = 90°C/min, Biomass particle size = 0.4 mm, and Sweeping gas flow rate = 100 mL/min). All the synthesized catalysts (KIT-6, NbKIT-6, and ZIF-8) were found to be highly efficient, and the maximum liquid yield was observed at 20 wt% of catalyst loading, i.e. 49.35% (KIT-6); 56.57% (NbKIT-6); and 52.74% (ZIF-8), respectively. The results revealed that compared to KIT-6, the maximum liquid yield was observed with NbKIT-6 catalyst i.e. 56.57% (Groundnut Stalk); 58.45% (Indian Rosewood); and 57.57% (Rice Straw), respectively. The proposed strategy will be highly economical and sustainable and the selected biomass could be a promising alternative and renewable energy source.


Introduction
Economic shoot-up, increasing population, unrestricted urbanization, and rapid technological developments are contributing toward the increase in global energy consumption.Depletion of fossil fuels contributes significantly to the rise in oil prices which directly affects the living standards.Despite continuous increase in noxious pollutants, there is a continuous depletion of energy sources derived from fossil resources (Li et al. 2019).According to energy consumption statistics 2019, fossil fuels accounted for 87% of the total energy supply, which includes oil (35.3%), coal (32%), and natural gas (26%) and is considered major sources of harmful emissions.Hence, a robust and sustainable alternative energy source is, therefore, one of the major concerns of the current global socio-economic reshaping.
Lignocellulosic biomass is considered a promising carbon-neutral and environment-friendly source for the production of fuels and chemicals and contributes 18-53% of global energy by 2030 (Bharath et al. 2020).It occupies a cardinal pole position with the ability to produce solids (biochar), liquids (tars and pyrolytic oil), and gases.Several factors are responsible for diversification in biomass including composition, location, favorable geographical conditions, availability, and processing technologies.Several thermochemical technologies are available that can effectively convert biomass into bio-based chemicals such as liquefaction, pyrolysis, and gasification (Aysu and Durak 2015).Pyrolysis being the most effective biomass conversion technology is a thermal decomposition of biomass in the absence of oxygen which facilitates the transformation of biomass into solid (carbonaceous), liquid, and gaseous products.
The expansion and intensification of agriculture and improper waste management resulted in an accelerated increase in noxious pollutants in the atmosphere.While biomass waste associated with agricultural crops is estimated to be over 3,300 megatons, cereal crops contribute more toward generating agricultural residues (Chen et al. 2020;Ding et al. 2019).The generation of huge quantities of such waste poses severe risks to human and environmental health.In contrast, India being an agrarian country generates a huge amount of agriculture-based residues annually and thus may be utilized as a potential, commercially profitable source for the production of platform chemicals and renewable fuels.
In this regard, the utilization of catalysts may accelerate the reaction rate, thereby altering both pyrolytic yield and physiochemical, mechanical, and thermal properties of the process.Utilization of catalysts makes significant alterations to the physiochemical properties and product selectivity and/or yield.Thermocatalytic pyrolysis was observed to enhance the product yield compared to only thermal pyrolysis.The challenges associated with product selectivity and yield during thermocatalytic pyrolysis can be easily overcome by utilizing effective catalysts.Some literature reports that the involvement of catalysts drastically enhances the liquid and gaseous yields while some report a sharp decline in the liquid and biochar yield depending on the acidity and surface area of the catalysts (Aysu and Durak 2016).Numerous kinds of research have demonstrated the influence of catalysts on product yield and selectivity during waste biomass pyrolysis.Qiuxiang Lu et al. 2020 demonstrated the catalytic pyrolysis of biomass for the production of aromatics using Ni/Ca-promoted Fe catalysts.The results revealed that the maximum yield was 72.57mL/g at 600°C and 91.19 mL/g at 750°C with N 2 pressure of 0.1 MPa using 5% Fe + 1.5% Ca + 0.8% Ni, respectively.Yiming Wang et al. 2022 demonstrated the upgradation of coal using a red mud-supported nickel catalyst.It was observed that the utilization of a catalyst facilitates the minimization of Iron Oxides in the red mud.The physiochemical modifications in the red mud enhance the tar quality.While the fraction of heavy components in tar significantly decreases from 27.2 wt.% (using red mud) to 10.1 wt.% (using 20 Ni/Red mud).Also, the maximum yield of light tar i.e. 7.7 wt% was obtained using 15Ni/Red mud.Rui Yuan et al. 2019 reported the catalytic pyrolysis of biomass-plastic wastes for the production of hydrocarbon-rich oils in the presence of MgO and MgCO 3 catalysts.The results revealed that there is a slight influence on gas evolution during pyrolysis using MgO catalyst, while MgCO 3 catalyst shows better efficiency for the generation of syngas (H 2 and CO) at 600-700°C.The generation of carbon dioxide was also suppressed by the MgCO 3 catalyst.Wei Chen et al. (2020) demonstrated the pyrolysis of bamboo wastes using N-doped biochar catalyst for the production of phenols.The results revealed that N-doped biochar catalyst significantly enhanced the production of phenols (82%) especially 4-vinyl phenol (31%) and 4-ethyl phenol (16%).Furthermore, it has led to an increase in aromatics while minimizing oxygen species and acetic acid generation, which resulted in high-purity bio-oil.
The above-discussed studies conclude that the thermochemical pyrolysis of biomass requires an effective catalyst; however, the cited literature utilizes catalysts which are non-tuneable, less effective, and have low regeneration and high decomposition rate during pyrolysis.However, such catalysts can be re-activated but require harsh temperature and pressure conditions.This degrades the quality and selectivity of the pyrolytic products and increases the quantity of char during pyrolysis.Therefore, the present study proposes the utilization of meso and microporous catalysts which exhibit uniform channels and cavities, high adsorption capacity, advantageous electronic properties, and active sites with different strengths.Also, the synthesized mesoporous and microporous catalysts offer a number of catalytically relevant features such as high thermal and hydrothermal stability, large surface area, uniform pores and voids, large pore size, and pore volume.
To the best of our knowledge, limited research is documented on the catalytic pyrolysis of agricultural wastes including Indian rosewood, rice straw, and groundnut stalk using meso and microporous catalysts.Therefore, the present study aims to investigate the pyrolytic behavior of all the selected agricultural wastes depending on the selectivity and yield of different pyrolytic products.The effect of different process variables including operating temperature, particle size, and heating rate was studied to optimize the pyrolysis process.A detailed comparison has also been studied to evaluate the performance of selected tunable mesoporous and microporous catalysts i.e.KIT-6, Nb-KIT6, and ZIF-8 on the pyrolytic products and the effect of acidity on the decomposition of agricultural wastes followed by the reaction mechanism of the pyrolysis behavior was also proposed.The present study proposes a highly effective, economical, and sustainable strategy for the catalytic pyrolysis of agricultural wastes.Also, the precise tuning of catalysts in terms of porosity and nanostructure could be a potential strategy toward developing novel meso-and microporous catalysts with indispensable characteristics for the efficient valorization of biomass.

Biomass procurement and preparation
Rice straw, groundnut stalk, and Indian rosewood were procured from local agricultural areas of Guru Gobind Singh Indraprastha University, New Delhi, India.The selected biomass was thoroughly washed with ultra water and then sundried for 2 days to eliminate the moisture.Then, the dried biomass was pulverized to the desired particle size and then stored in airtight plastic bags for further experiments.

Preparation and synthesis of mesoporous and microporous catalysts
All the mesoporous and microporous catalysts namely KIT-6 (Korean Institute of Science and Technology-6), niobium impregnated KIT-6, and ZIF (Zeolitic Imidazole Framework) were synthesized according to our previously reported study (Tyagi and Anand 2022a).

Biomass characterization
All the selected biomasses namely rice straw, groundnut stalks, and Indian rosewood were subjected to Proximate and Ultimate analysis, TGA, and FTIR.Also, the synthesized catalysts were subjected to Fourier Transform Infrared Spectroscopy, Brunauer-Emmett-Teller, Energy Dispersive X-ray Spectroscopy, Thermogravimetric Analysis, X-ray Diffraction, and Field Emission Scanning Electron Microscopy.All the characterizations of the synthesized catalysts were discussed in detail in our previous study (Tyagi and Anand 2022a).

Pyrolysis experiments
This study was conducted in a semi-batch reactor that was designed and laid out with precision.The setup consists of an electrically heated furnace, thermocouple (K-type), double condenser, and PID controller.The effect of the process variables on the pyrolytic products was analyzed at varying operating temperatures in the range of 350°C to 600°C with a step size of 100°C with different heating rates in the range of 50°C to 140°C/min.Each experiment consisted of a single bed arrangement with 50 g of biomass with a constant nitrogen flow rate of 100 mL min −1 .A water-cooled condenser was used to condense vapors generated after pyrolysis using a chiller at 4°C.Separator was used to collect condensed liquid at the bottom.The liquid product contained bio-oil and trace amounts of water.Bio-oil was separated from the aqueous fraction by mixing equal amounts of diethyl ether with the liquid product.Anhydrous sodium sulfate was applied to the bio-oil for drying, followed by evaporation at 25°C in a rotary evaporator to remove the remaining diethyl ether.Experimental data were presented with a standard deviation of 2% based on triplicate experiments.The yield of liquid, solid (char), and non-condensable products was calculated using the following equations;

Characterization of pyrolytic oil
The obtained liquid oil from rice straw, groundnut stalk, and Indian rosewood biomass was readily separated by the density difference.The upper phase containing liquid is rich in organic compounds, while the bottom phase containing liquid is rich in aqueous (water-soluble hydrocarbons and trace fraction of acids).The calorific value was determined using an oxygen bomb calorimeter (Parr Instrument Company, USA, Model 1341 Plain Jacket Calorimeter).Bulk density was measured with a density meter (DM 2910 Anton Parr), while viscosity was measured with Interfacial Rheometer (G7821B Agilent 1260 Infinity) at 40°C with uniform stirring of 50 RPM.In addition, pH and moisture content were measured with the Seven Excellence S400-Basic, pH/mV benchtop meter.

Analysis of liquid products via GC-MS
Pyrolytic oil was also analyzed using GC-MS (8890 GC, Agilent) consisting of Elite 5 MS column (Diameter = 0.250 mm and Length = 30 m).GC-MS was initially operated with an oven temperature of 40°C for 1 min and then increases to 300°C with a heating rate of 10°C/min under a Helium atmosphere (0.8 mL/min).Dichloromethane was used to dilute the pyrolytic oil, and the diluted sample (1.0 mL) was directly introduced into the column.The analysis of the obtained spectra at varied retention times was performed using the NIST library.

Characterization of catalysts
The synthesized catalysts including KIT-6, NbKIT6, and ZIF-8 were successfully characterized and analyzed using FTIR, XRD, BET, TGA, Fe-SEM, and EDS analysis.The results revealed that all the catalysts exhibit promising physiochemical properties.The obtained results are reported in our previous study (Tyagi and Anand 2022a).

Physical and chemical characterizations of biomass
Table 1 summarizes the physiochemical characteristics of rice straw, groundnut stalk, and Indian rosewood.The proximate analysis confirms high volatile matter and low ash content in each biomass, i.e. 76.24% (rice straw), 78.17% (groundnut stalk), and 79.22% (Indian rosewood) indicating better combustion of fuel.In addition, the results of the Ultimate analysis confirm high carbon content, i.e. 52.58% (rice straw), 53.45% (groundnut stalk), and 47.36% (Indian rosewood) with less nitrogen content and negligible sulfur content in each biomass, respectively.This confirms the infinitesimal formation of SO x and NO x during pyrolysis leading to low corrosion effects during boiler operation.Also, the presence of low moisture content in the biomass (<10 wt%) makes it a highly promising and ideal feedstock.Moreover, the magnitude of bulk density and heating value for all the biomass was highly significant and the chemical analysis indicates the significant percentage of constituents in all the biomass (Wang et al. 2021).

TGA analysis of biomass
Thermal analysis was carried out on rice straw and groundnut stalks under non-isothermal conditions in an inert atmosphere.During pyrolysis, all the biomass undergoes three stages, including drying, devolatilization (active stage), and the formation of char (passive stage).In Stage 1 (drying), the elimination of water molecules and other low molecular weight compounds takes place at a temperature of 150°C.While in Stage 2 (devolatilization), the transformation of high molecular weight compounds to low molecular occurs in a temperature range of 150°C-500°C.During devolatilization, a major portion of hemicellulose and cellulose decomposes and releases a large number of volatile compounds.While >500°C maximum fraction of lignin was decomposed at a very slow rate due to high thermal stability (that occurs due to the existence of hydroxyl, carboxylic, and phenolic groups).The high content of lignin in biomass leads to the high formation of char which may be useful for several applications including the production of solid fuels, bio-adsorbents, carbon nanotubes, and soil conditioners or enhancers.Also, the DTG curve confirms the appearance of the first peak below 150°C, i.e., (63.32°C for Rice Straw and 68.94°C for Groundnut stalks), indicating the effective removal of moisture and other soluble compounds having low molecular weight.Meanwhile, the presence of a second peak at 235°C and 285°C and a third peak at 325°C and 370°C for Rice Straw and Groundnut Stalk confirm the presence of hemicellulose and cellulose, respectively.This concludes that <10.25% of biomass is readily decomposed in Stage 1, while ~74.0%(Rice Straw) and 64.0%(Groundnut Stalk) were decomposed in Stage 2 and <7.15% of the biomass was decomposed in Stage 3.

FT-IR analysis of biomass
Infrared spectroscopy was used to examine the physical, chemical, and conformational changes in Rice Straw and Groundnut Stalk biomass after pyrolysis.The obtained spectra confirm the existence of a wide range of compounds including alkanes, phenols, alkenes, aldehydes, aromatics, and alcohols.The peak near 3000-3500 cm −1 confirms the stretching of hydroxyl groups in the pyrolyzed biomass and hence indicates the presence of moisture, proteins, phenols, alcohols, aromatics, and a trace amount of acid.Meanwhile, the appearance of a peak at 2931 cm −1 is attributed to CH 2 (asymmetric) and CH 3 (symmetric) stretching (Patel, Agrawal, and Rawal 2020).The presence of hemicellulose was confirmed by stretching of carbonyl groups (C=O) near 1634-1663 cm −1 in the pyrolyzed biomass.Also, the presence of alkanes and alkenes was corroborated by the vibration of C-H and =C-H groups at 2634 cm −1 and the existence of methyl and phenolic compounds indicate the stretching of aliphatic C-H groups near 1369-1407 cm −1 .In addition, a peak near 1040-1044 cm −1 indicates that the C-O group vibrations show the presence of ether and ester compounds.Meanwhile, peaks near 911-661 cm −1 confirm the bending of the O-H group, thus indicating the existence of mono and/or polycyclic substituted aromatic groups.

Process optimization
Thermocatalytic pyrolysis is influenced by several process variables, therefore optimization of the process is highly crucial to achieving high selectivity and yield of pyrolytic products (solid, liquid, and gases).Biomass pyrolysis is dependent on several variables including process temperature, sweep gas flow rate, heating rate, pressure, and particle size, and these parameters drastically affect the yield and selectivity of the products.Therefore, the present work highlights the detailed effect of three major variables including reactor temperature, heating rate, and feedstock particle size.

Impact of process temperature
The effect of process temperatures ranging from 350°C to 600°C was studied on the pyrolysis of different biomasses, namely rice straw, groundnut stalk, and Indian rosewood biomass as shown in (Figure 1a-c).
Results unveiled that on raising the temperature from 350°C to 500°C, liquid yield increases gradually from 31.22% to 42.57% (Groundnut Stalk); 34.78% to 43.45% (Indian rosewood), and 30.25% to 45.02% (Rice Straw), respectively.Meanwhile, further elevation in the temperature to 600°C declines the formation of liquid products to 35.12%, 38.87%, and 36.22% for groundnut stalk, Indian rosewood, and rice straw, respectively.The maximum yield of the liquid products was obtained at 500°C for all the biomasses due to effective heat and mass transfer which resulted in complete combustion.In addition, with an increase in temperature from 350°C to 600°C gradual declines in the solid yield (char) were observed, while the yield of gaseous products increases gradually from 28.33% to 40.21% (Groundnut Stalk); 33.21% to 45.09% (Indian rosewood); and 30.11% to 48.10% (Rice Straw), respectively.Due to the rapid endothermic disintegration of biomass, transformation of condensable gases noncondensable gases takes place.Also, due to lower heat and mass transfer, partial combustion was observed at lower temperatures, resulting in the formation of char (Patel, Agrawal, and Rawal 2020).

Impact of heating rate
The impact of heating rate was also studied in the range of 50°C/min to 140°C/min at an optimum temperature of 500°C and the results are summarized in (Figure 2a-c).The results unveiled that on increasing the heating rate from 50°C/min to 90°C/min, liquid yield gradually increases from 37.54% to 42.09% (Groundnut Stalk); 35.21% to 43.55% (Indian rosewood), and 31.25% to 45.15% (Rice Straw), respectively.Meanwhile the further increase in the heating rate to 140°C/min declines the formation of liquid products, i.e. 32.12% (Groundnut Stalk); 33.64% (Indian rosewood), and 28.49% (Rice Straw), respectively.At a lower heating rate (50°C/min) yield of liquid and gaseous products were lower as compared to solid yield, which may be due to the partial combustion of the biomass (low rate of heat and mass transfer).Meanwhile, at a higher heating rate (>90°C/min), the liquid and solid yields decrease gradually with the increase in the yield of gaseous products, which is due to the prompt endothermic disintegration of the biomass.Results revealed that the decomposition of tar occurred more rapidly at higher temperatures, thereby increasing the release of volatile compounds.Also, at a higher heating rate, the formation of secondary reactions (cracking of tar and repolymerization) was minimized due to the short residence time.

Impact of particle size
The effect of particle size was varied in the range of 0.4 mm to 2 mm at an optimum heating rate of 90°C/min and a reactor temperature of 500°C as shown in (Figure 3a-c).Results unveiled that increasing particle size from 0.4 mm to 2 mm, gradually increases the yield of solid products (char), i.e. 25.89% to 45.89% (Groundnut Stalk); 30.12% to 47.90% (Indian Rosewood), and 38.45% to 23.87% (Rice Straw), respectively.While the liquid yield gradually decreases from 43.21% to 25.56% (Groundnut Stalk); 32.09% to 18.09% (Indian Rosewood); and 45.21% to 30.49% (Rice Straw), respectively.Also, the yield of gaseous products decreases from 35.87% to 22.89% (Groundnut Stalk); 38.76% to 25.25% (Indian Rosewood); and 29.24% to 19.35% (Rice Straw), respectively.It was observed that for rapid pyrolysis, biomass particles with a smaller particle size are preferred as they heat quickly and uniformly, thus generating a hot volatile compound that condenses into liquids.However, heat transfer within biomass is limited by larger particle size, which accelerates thermal lag between particles and reduces product yield (Ge et al. 2021).Therefore, biomass with a large particle size requires a greater amount of activation energy.
In addition to the above process parameters, the flow rate of sweeping gas was kept constant i.e. 100 mL/min according to our previous study (Tyagi, Anand, and Jain 2022b).Therefore, based on the results (Figures 3 to 5) 500°C temperature with a heating rate of 90°C/min and a particle size of 0.4 mm were considered as optimum conditions for the effective pyrolysis of selected biomass, namely Groundnut Stalk, Indian rosewood, and Rice Straw.

Impact of type of catalysts and loading on product yield
Catalyst acidity and its loading play a vital role during the pyrolysis of biomass and its subsequent transformation to pyrolytic products.Therefore, the effect of catalyst loading ranging from 5 wt% to 40 wt% was studied under optimum conditions using different mesoporous and microporous catalysts, namely ZIF-8, KIT-6, and NbKIT-6.Figure 4a-c reveals the significant effect of each catalyst and its loading during the pyrolysis of each biomass.Results unveiled that with the increase in catalyst loading from 0 wt% to 20 wt% liquid yield increases gradually from 39.24% to 49.35% (KIT-6); 45.24% to 56.57% (NbKIT-6); and 43.45% to 52.74% (ZIF-8), respectively, using Groundnut Stalk biomass.Meanwhile the further increase in catalyst loading to 40 wt% declines the formation of liquid products to 40.26%, 41.37%, and 49.57% for ZIF-8, KIT-6, and NbKIT-6 catalysts, respectively.The maximum liquid yield was obtained at a catalyst loading of 20 wt% for all the catalysts due to the due to suitable acidity during pyrolysis.In addition, solid yield (char) was also observed to decline with an increase in catalyst loading to 20 wt%, while a further increase in catalyst loading to 40 wt% increases the char formation to 33.24%, 36.72%, and 28.56% for KIT-6, NbKIT-6, and ZIF-8 catalysts, respectively.Also, the maximum yield of gaseous products was observed as 37.24% (KIT-6); 45.98% (NbKIT-6) and 42.91% (ZIF-8) using Groundnut Stalk biomass.The suitable acidity and loading of the catalyst induce appropriate acidity and facilitate the minimization of insoluble compounds.This ensures high product selectivity and yield with easy separation (Tyagi and Anand 2022a).Also, the detailed mechanism of each catalyst was already discussed in our previous study (Tyagi and Anand 2022a).
The discussed mechanistic approach and the obtained experimental data conclude that both the microporous and mesoporous catalysts are highly efficient during the pyrolysis of each biomass.However, enhancement in the liquid yield was observed with the addition of microporous or mesoporous catalysts.This may be due to the following reasons including large pore volume that introduces isomer selectivity during pyrolysis, homogeneous active site distribution, and high periodicity and regularity of active catalytic sites (Cao et al. 2018).Figure 5a-c depicts the comparison of catalyst performance on the pyrolysis of other biomasses, namely Indian rosewood and rice straw.It was observed that all biomasses show a similar trend in terms of product yield and selectivity under optimized conditions.The results revealed that compared to KIT-6, the maximum liquid yield was observed with NbKIT-6 catalyst i.e. 56.57% (Groundnut Stalk); 58.45% (Indian Rosewood), and 57.57% (Rice Straw).Also, the ZIF-8 catalyst results in a significant liquid yield, i.e. 52.74% (Groundnut Stalk); 57.74% (Indian Rosewood) and 55.15% (Rice Straw).In contrast, all the catalysts were found to be effective in producing gaseous products.In conclusion, the selected catalysts are environmentally friendly, highly stable at high temperatures, nontoxic and require low designing costs (Gao and Goldfarb 2019;Tyagi and Anand 2022a).

Pyrolytic oil characterization
Thermal and catalytic pyrolytic oils were characterized, and the results are summarized in (supplementary material).It was observed that irrespective of the biomass used, catalytic pyrolytic oil possesses lower viscosity as compared to thermal pyrolytic oil.It was observed that the high viscosity of pyrolytic oil leads to several challenges in fuel atomization thereby resulting in poor engine performance (Tyagi et al. 2022b).The calorific value and acidity of catalytic pyrolytic oil were also higher as compared to thermal pyrolytic oil which may be due to the vaporization of oxygen to form CO, CO 2 , and H 2 O.In addition, the heating value of catalytic pyrolytic oil was significantly higher at low density, which provides an added advantage during atomization.Further, catalytic pyrolytic oil contains low ash content which minimizes the tar content and results in low ash slagging and fouling tendency hence making it more suitable for boiler operations.

FT-IR analysis of pyrolytic oil
FTIR spectra of thermally active and catalytic pyrolytic oil show significant changes after pyrolysis.Peaks near 3650-3660 cm −1 correspond to the stretching of the hydroxyl group which indicates the existence of alcohols, aromatics, water, phenols, acids, and proteins.Also, peaks near 2960-2850 cm −1 accredit to the C-H group stretching, indicating the existence of alkanes, while peaks near 1412-1553 cm −1 correspond to the vibration of C-C bonds, confirming the existence of alkynes (Arif et al. 2021).In addition, the peak at 1389 cm −1 shows the presence of esters due to the deformation of the C-O group in the pyrolytic oil.Peaks near 2275-2335 cm −1 confirm the existence of aliphatic cyanide/nitrile groups, whereas peaks near 1269-1389 cm −1 indicate the appearance of alcohols.Furthermore, the peaks near 1719-1732 cm −1 correspond to the existence of carboxylic acid, while the peaks near 1065-1093 cm −1 are attributed to the C-H stretching, which confirms the appearance of aromatic compounds.

GC-MS analysis
Figure 6a-c depicts the presence of different compounds obtained after the pyrolysis of the entire biomass.The obtained pyrolytic oil contains more than 285 organic compounds which comprise the following classes: aliphatic, oxygenated, monoaromatic, nitrogenated, polyaromatic, and heterocyclic compounds.However, the most common compounds were carboxylic acids, ketones, alkanes, amides, phenols, aromatics, ethers, furan, alkenes, amines, benzene, alcohols, levoglucosan, nitriles, and esters.Results revealed that pyrolytic oil contains a higher fraction of alcohols, esters, phenols, amides, nitriles, and acids with a low fraction of sulfur-containing compounds.The presence of several oxygenated compounds including esters, ketones, and ethers reduces the fluidity and stability of the pyrolytic oil.In addition, tetra decanoic acid and octadecanoic acid in pyrolytic oil make it highly useful for several applications including the manufacturing of soaps and detergents, as a nondrying oil for surface coatings and cosmetic agents.Also, catalytic pyrolytic contains several compounds such as heptadecane, octadecanenitrile, 9-octadecenamide, pentadecane, 9-octadecenoic acid methyl ester, oleanitrile, and 11-hexadecenal.The results revealed that the utilization of catalysts (ZIF-8, KIT-6, and NbKIT-6) significantly enhances the distribution of pyrolytic products.

Conclusion
The present work highlights the physicochemical analysis and pyrolysis of agricultural wastes via thermocatalytic route.Results concluded that both the microporous and mesoporous catalysts were highly efficient during the pyrolysis under optimum process conditions.The synthesized catalysts were found to have uniform channels and cavities, high adsorption capacity, advantageous electronic properties, and active sites with different strengths.The high percentage of carbon (52.58%, 53.45%, and 47.36%) and low moisture content (4.15%, 3.39%, and 4.24%) offers great advantage of the selected biomasses during pyrolysis.All the biomasses showed high product yield and selectivity, and the maximum yield of liquid products was observed at 20 wt% catalyst loading.The maximum yield of gaseous products was observed as 37.24% (KIT-6); 45.98% (NbKIT-6) and 42.91% (ZIF-8) using Groundnut Stalk biomass compared to other biomasses.Furthermore, catalytic pyrolytic oil shows excellent fuel properties and possesses significant viscosity, calorific value, and acidity, while GC-MS analysis confirms the presence of various organic compounds.This study concludes that the utilization of microporous and mesoporous catalysts is highly cost-effective and sustainable and can lead to highquality liquid fuels.However, the future work can be extended to investigate the pyrolytic behavior of waste plastics, e-waste, and pharmaceutical wastes with different reactor configurations.In addition, purity and quality of downstream can also be enhanced with co-pyrolysis or two-stage pyrolysis strategy.
Prof. Arinjay Jain is currently working as Professor in the University School of Chemical Technology, Guru Gobind Singh Indraprastha University, New Delhi, India.He has more than 25 years of Teaching /Research experience.His research areas include Bioprocess engineering, Industrial Pollution and Abatement, Adsorption, Waste Management and Sustainable manufacturing.He has published more than 35 International peer reviewed research papers in Elsevier and Springer, Wiley Journals and contributed to several edited books.He has guided/supervised several PhDs and presented number of research papers in national/international conferences within and outside India.

Credit author statement
Uplabdhi Tyagi Experimental work, Data Interpretation, Manuscript Writing.Neeru Anand Principal investigator and Conceptualization.Arinjay Jain Editing and Interpretation of data.

Figure 1 .
Figure 1.Impact of temperature on pyrolytic products using (a) Groundnut Stalk (b) Indian rose Wood (c) Rice Straw.

Figure 2 .
Figure 2. Impact of heating rate on pyrolytic products using (a) Groundnut Stalk (b) Indian rose Wood (c) Rice Straw.

Figure 3 .
Figure 3. Impact of particle size on pyrolytic products using (a) Groundnut Stalk (b) Indian rosewood (c) Rice Straw.

Figure 5 .
Figure 5. Impact of catalyst type on pyrolytic products using different biomass (a) Groundnut Stalk (b) Indian rosewood (c) Rice Straw.

Table 1 .
Physicochemical characterization of rice straw, groundnut stalk, and Indian rosewood biomass.