Posted in | News | Materials Research

Date Palm Seeds Used to Produce Syngas and Biochar

In an article recently published in the open-access journal Energies, researchers discussed the non-catalytic valorization of date palm seeds for the production of hydrogen-rich syngas and biochar.

Study: Hydrogen-Rich Syngas and Biochar Production by Non-Catalytic Valorization of Date Palm Seeds. Image Credit: Rui Elena/Shutterstock.com

Background

To satisfy future energy needs, there is widespread interest in integrating renewable energy sources to partially replace or supplement conventional fossil fuels. Because of its renewable nature, ubiquitous availability, and carbon-neutral qualities, biomass has emerged as a key component of a sustainable and renewable energy network in recent years.

Environmental impacts and rising energy demands have necessitated the use of sustainable renewable energy sources such as photovoltaic and wind energy in recent decades. Lignocellulosic waste, municipal solid waste, industrial waste, and a variety of organic wastes are all examples of biomass energy sources.

Furthermore, when date seeds are utilized as a direct fuel, they release nitrogen-containing organic chemicals into the atmosphere, causing environmental issues. Previous research has suggested that date seed oil obtained using conventional extraction processes be used following catalytic up-gradation. Pyrolysis is known to be a useful thermochemical approach for transforming complicated biomaterials.

Schematic representation of the custom-made fixed-bed fast pyrolyzer.

Schematic representation of the custom-made fixed-bed fast pyrolyzer. Image Credit: Sait, H. H et al., Energies

About the Study

In this study, the authors presented the development of a fixed-bed pyrolyzer and used it to pyrolyze mixed date palm seeds sourced from Saudi Arabia. The effect of pyrolysis temperature (200–1000 °C) on the various physicochemical properties of date seed biochar and hydrogen-rich syngas formed by the pyrolysis process was examined. Flynn–Wall–Ozawa (FWO), Friedman, and Kissinger–Akahira–Sunose (KAS) linearized model-free approaches, as well as non-linear methods like Vyazovkin and advanced Vyazovkin, were used to fit the kinetic data of date seed pyrolysis.

The researchers thermodynamically pyrolyzed date seeds in a modified fixed-bed pyrolyzer to create hydrogen-rich syngas and biochar with a wide range of industrial applications. A 1500 W multipurpose high-speed grinder was used to grind air-dried seeds. The undersize powder, which had been sieved through 200 mesh and contained particles as small as 500 microns, was saved for additional investigation.

The team used an elemental analyzer to determine the sample's final analysis. At a 5 kV accelerating voltage, a scanning electron microscope with energy-dispersive X-ray spectroscopy was utilized to analyze biochar shape and elemental composition. Helium gas was used as a carrier at a flow rate of 20 mL/min, with an operating column temperature of 120 °C, column pressure of 90 psi, and a detector temperature of 150 °C.

SEM images of the valorized date seed at (a) 400 °C, (b) 600 °C, (c) 800 °C, and (d) 1000 °C.

SEM images of the valorized date seed at (a) 400 °C, (b) 600 °C, (c) 800 °C, and (d) 1000 °C. Image Credit: Sait, H. H et al., Energies

Observations

The lignocellulosic elements cellulose, lignin, and hemicellulose had a high carbon content in both proximate and final analysis. As per the energy-dispersive X-ray (EDX) studies, the constituent components of biochar changed with the pyrolysis temperature.

Date seeds pyrolyzed at 800 °C had the highest carbon concentration, which accounted for 97.99% of the corresponding total carbon content. The biochar was found to have a high percentage of carbon, as well as potassium and magnesium. The highest carbon monoxide and hydrogen compositions were achieved at 1000 °C, with 32 mol% and 40 mol%, respectively.

Friedman, KAS, and FWO activation energies ranged from 30–75 kJ/mol, 30–40 kJ/mol, and 30–65 kJ/mol, respectively, while advanced Vyazovkin and Vyazovkin activation energies ranged from 30-70 kJ/mol and 25–30 kJ/mol, respectively. In comparison to Friedman, the FWO and KAS models had less variation. The date seeds had 4.1% moisture, 78% volatile matter, 9.2% fixed carbon, and 8.25% ash, according to the proximate analysis. The date seed comprised 47.15% carbon, 7.52% hydrogen, 0.82% nitrogen, and 44% oxygen. Date seed had 33.1% cellulose, 24.3% hemicellulose, and 22.6% lignin.

Carbon dominated the valorized date seeds with 88% content at 400 °C, followed by 10.28% oxygen, 0.28% magnesium, and 0.48% phosphorus. The carbon content of valorized date seeds increased to 94.6% at 500 °C, but oxygen, phosphorus, and magnesium content declined to 4.66%, 0.21%, and 0.13%, respectively. A 0.31% trace sulfur level was also discovered.

When the temperature was raised to 800 °C, the carbon content increased to 97.99%. With an increase in pyrolysis temperature, the composition of syngas increased, which resulted in the highest CO and H2 compositions of 32 mol% and 40 mol%, respectively. At 200 °C, the CO2 concentration increased to 0.9 mol%, and at 1000 °C, is incremented to 5.6 mol%. The Friedman, FWO, and KAS models yielded apparent activation energies of 229.5, 226.8, and 224.2 kJ/mol, respectively.

Activation energy as a function of conversion for the linear and non-linear methods.

Activation energy as a function of conversion for the linear and non-linear methods. Image Credit: Sait, H. H et al., Energies

Conclusions

In conclusion, this study elucidated the pyrolysis of date palm seeds in a fixed-bed pyrolyzer at heating rates of 2.5, 5, 7.5, and 10 °C/min to create biochar. The complicated deterioration of the date seed during pyrolysis occurred in the active pyrolysis zone. The R2 and standard deviation values obtained from fitting the data to the KAS and FWO models were greater than those obtained from other models.

The authors believe that the obtained kinetic parameters could aid in the development of a suitable pyrolyzer for Saudi Arabian date seeds.

Source

Sait, H. H., Hussain, A., Bassyouni, M., et al. Hydrogen-Rich Syngas and Biochar Production by Non-Catalytic Valorization of Date Palm Seeds. Energies 15(8) 2727 (2022). https://www.mdpi.com/1996-1073/15/8/2727

Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of AZoM.com Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.

Surbhi Jain

Written by

Surbhi Jain

Surbhi Jain is a freelance Technical writer based in Delhi, India. She holds a Ph.D. in Physics from the University of Delhi and has participated in several scientific, cultural, and sports events. Her academic background is in Material Science research with a specialization in the development of optical devices and sensors. She has extensive experience in content writing, editing, experimental data analysis, and project management and has published 7 research papers in Scopus-indexed journals and filed 2 Indian patents based on her research work. She is passionate about reading, writing, research, and technology, and enjoys cooking, acting, gardening, and sports.

Citations

Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Jain, Surbhi. (2022, April 12). Date Palm Seeds Used to Produce Syngas and Biochar. AZoM. Retrieved on July 07, 2022 from https://www.azom.com/news.aspx?newsID=58790.

  • MLA

    Jain, Surbhi. "Date Palm Seeds Used to Produce Syngas and Biochar". AZoM. 07 July 2022. <https://www.azom.com/news.aspx?newsID=58790>.

  • Chicago

    Jain, Surbhi. "Date Palm Seeds Used to Produce Syngas and Biochar". AZoM. https://www.azom.com/news.aspx?newsID=58790. (accessed July 07, 2022).

  • Harvard

    Jain, Surbhi. 2022. Date Palm Seeds Used to Produce Syngas and Biochar. AZoM, viewed 07 July 2022, https://www.azom.com/news.aspx?newsID=58790.

Tell Us What You Think

Do you have a review, update or anything you would like to add to this news story?

Leave your feedback
Your comment type
Submit