Performance Evaluation of Green Adsorbent (Neem Leaf Powder) for Desulfurization of Petroleum Distillate

The release of sulfur-containing compounds during direct combustion of diesel fuel has caused environment issues which require urgent attention. Recently, stringent environmental regulations by the Environmental Protection Agency (EPA) to minimise the total sulfur-containing compounds released into the atmosphere have intensified the research in this area. In this present study, adsorption experiments in batch mode were conducted using an activated green adsorbent (Neem leaves powder) to reduce the amount of dibenzothiophene (DBT) in a synthetic oil. The synthetic oil was prepared by dissolving 0.1 g of dibenzothiophene (DBT) in 100 mL of hexane. Various analytical techniques were used such as; Scanning electron microscopy (SEM) to check the morphological structure of the adsorbent. Nitrogen adsorption and desorption experiments (Brunauer-Emmett-Teller, BET) at 77 K were used to check the surface area, pore size and pore volume of the adsorbent. N2 physio-sorption at 77 K before and after adsorption showed adsorption of DBT molecules onto the surface of the adsorbent after adsorption experiment. The results showed about 65.78 % removal of DBT at temperature of 30oC and adsorbent amount of 0.8 g. Therefore, neem leave powder could be an alternative cheap adsorbent to reduce the concentration of organo-sulfur compound in petroleum distillates. This may offer new perception into the development and application of green materials in sustainable, innovative and effective waste management and abatement of environmental pollution

Evaluation of adsorption and kinetics of neem leaf powder (Azadirachta indica) as a bio-sorbent for desulfurization of dibenzothiophene (DBT) from synthetic diesel

The need for a sustainable environment has necessitated the development of a green adsorbent that is efficient, cheap, and readily available to serve as an alternative adsorbent for the removal of the refractory sulfur-containing compound from diesel. In this current study, neem-leaf powder (NLP) was activated using H2SO4 and tested in desulfurization adsorption experiments of synthetic diesel containing Dibenzothiopene (DBT) during a batch operation. The synthetic diesel contained 0.1 g of DBT in 100 mL of hexane. Before testing, physio-chemical characteristics of the adsorbent were checked via Fourier transmission infrared (FTIR) spectroscopy for surface chemistry; via N2 physisorption at 77 K for textural properties; SEM quipped with EDX for morphology and elemental composition; and XRD for purity and crystallinity. The results showed that the physico-chemical nature of the adsorbent played a significant role in enhancing the adsorption capacity of the material for DBT. Activated NLP displayed DBT removal of 65.78% at 30 �C using 0.8 g of the adsorbent. Furthermore, the behaviour of the adsorbent during the adsorption could be adequately described using the Freundlich isotherm model. Pseudo-first-order and pseudo-second-order kinetics model describe well the adsorption kinetics of DBT onto the activated NLP

Adsorptive removal of BTEX compounds from wastewater using activated carbon derived from macadamia nut shells

In this study, adsorptive removal of benzene, toluene, ethylbenzene and xylenes (BTEX) from synthetic water using activated carbon adsorbent derived from macadamia nut shells was investigated. The surface  functional groups of the synthesized adsorbents were assessed by Fourier transform infrared spectra. The specific surface area, pore size and pore volume at 77 K nitrogen adsorption, surface morphology, and the crystalline structure of the adsorbents were determined using Brunauer-Emmett-Teller, scanning electron microscopy and x-ray diffraction, respectively. Batch adsorption mode was used to evaluate the performance of the activated carbon. The stock solutions of synthetic wastewater were prepared by dissolving 100 mg/L of each of the BTEX compound into distilled water in a 250 mL volumetric flask. Effect of initial concentration of BTEX compounds, contact time, and mass of adsorbent on the removal of BTEX compounds from the synthetic wastewater was investigated. The macadamia nut shell–derived activated carbon (MAC) proved to be an effective adsorbent for BTEX compounds, with a large surface area of 405.56 m2/g. The exposure time to reach equilibrium for maximum removal of BTEX was observed to be 20 min. The adsorption capacity of the BTEX compounds by MAC followed the following adsorption order: benzene > toluene > ethylbenzene > xylene.&nbsp

Mathematical modelling and kinetics of thermal decomposition of corn stover using thermogravimetry (TGA-DTG) technique

Lignocellulosic biomass could be pyrolytically converted into value-added products and one of the steps during the pyrolysis is thermal decomposition which involves multiple reactions. Therefore, mathematical modelling of thermal decomposition could provide molecular insight into thermal degradation reactions by providing accurate prediction of the phases of the multi-component reactions in particular nucleation, growth and boundaryphase reactions occurring under different working conditions. In this study, thermal decomposition behaviour of Corn Stover was explored using thermogravimetry technique (TGA-DTG) at heating rates of 20, 30, 40 and 50 °C/min under nitrogen gas flow (55 mL/min) and oxygen gas flow at 15 mL/min. The Flynn-Wall Ozawa (FWO) and Kissinger Akahira Sunose (KAS) models were used to estimate the kinetic parameters such as apparent activation energy, pre-exponential factor and order of reaction so as to be able to design the pyrolytic reactor that could be used for the biomass conversion. The hemicellulose maximum mass loss rate was at 300 °C, cellulose at 410 °C and lignin decomposition from 190 °C to 620 °C. The apparent activation energies calculated ranged from 44.39 -134.81 kJ/mol using the FWO method while the KAS method gave 87.83 - 282.41 kJ/mol

Evaluation of adsorption and kinetics of neem leaf powder (Azadirachta indica) as a bio-sorbent for desulfurization of dibenzothiophene (DBT) from synthetic diesel

The need for a sustainable environment has necessitated the development of a green adsorbent that is efficient, cheap, and readily available to serve as an alternative adsorbent for the removal of the refractory sulfur-containing compound from diesel. In this current study, neem-leaf powder (NLP) was activated using H2SO4 and tested in desulfurization adsorption experiments of synthetic diesel containing Dibenzothiopene (DBT) during a batch operation. The synthetic diesel contained 0.1 g of DBT in 100 mL of hexane. Before testing, physio-chemical characteristics of the adsorbent were checked via Fourier transmission infrared (FTIR) spectroscopy for surface chemistry; via N2 physisorption at 77 K for textural properties; SEM quipped with EDX for morphology and elemental composition; and XRD for purity and crystallinity. The results showed that the physico-chemical nature of the adsorbent played a significant role in enhancing the adsorption capacity of the material for DBT. Activated NLP displayed DBT removal of 65.78% at 30 °C using 0.8 g of the adsorbent. Furthermore, the behaviour of the adsorbent during the adsorption could be adequately described using the Freundlich isotherm model. Pseudo-first-order and pseudo-second-order kinetics model describe well the adsorption kinetics of DBT onto the activated NLP.L’Oréal-UNESCO foundation for Women in Science, Sub-Saharan African Fellowship.https://www.sciencedirect.com/journal/journal-of-saudi-chemical-societyhj2023Chemical Engineerin

Effect of silica sodalite loading on SOD/PSF membranes during treatment of phenol-containing wastewater

In this study, silica sodalite (SSOD) was prepared via topotactic conversion and different silica sodalite loadings were infused into the polysulfone (PSF) for application in phenol-containing water treatment. The composite membranes were fabricated through the phase inversion technique. Physicochemical characteristics of the nanoparticles and membranes were checked using a Scanning Electron Microscope (SEM), Brunauer Emmett–Teller (BET), and Fourier Transform Infrared (FTIR) for surface morphology, textural properties, and surface chemistry, respectively. A nanotensile test, Atomic Force Microscopy (AFM), and contact angle measurement were used to check the mechanical properties, surface roughness, and hydrophilicity of the membranes, respectively. SEM results revealed that the pure polysulfone surface is highly porous with large evident pores. However, the pores decreased with increasing SSOD loading. The performance of the fabricated membranes was evaluated using a dead-end filtration device at varying feed pressure during phenol-containing water treatment. The concentration of phenol in water used in this study was 20 mg/L. The pure PSF displayed the maximum phenol rejection of 95 55% at 4 bar, compared to the composite membranes having 61.35% and 64.75% phenol rejection for 5 wt.% SSOD loading and 10 wt.% SSOD loading, respectively. In this study, a novel Psf-infused SSOD membrane was successfully fabricated for the treatment of synthetic phenol-containing water to alleviate the challenges associated with it.https://www.mdpi.com/journal/membranesam2023Chemical Engineerin

Effect of silica sodalite functionalization and PVA coating on performance of sodalite infused PSF membrane during treatment of acid mine drainage

In this study, silica sodalite (SSOD) nanoparticles were synthesized by topotactic conversion and functionalized using HNO3/H2SO4 (1:3). The SSOD and functionalized SSOD (fSSOD) nanoparticles were infused into a Polysulfone (Psf) membrane to produce mixed matrix membranes. The membranes were fabricated via the phase inversion method. The membranes and the nanoparticles were characterized using Scanning Electron Microscopy (SEM) to check the morphology of the nanoparticles and the membranes and Fourier Transform Infrared to check the surface chemistry of the nanoparticles and the membranes. Thermal stability of the nanoparticles and the membranes was evaluated using Themogravimetry analysis (TGA) and the degree of hydrophilicity of the membranes was checked via contact angle measurements. The mechanical strength of the membranes and their surface nature (roughness) were checked using a nanotensile instrument and Atomic Force Microscopy (AFM), respectively. The textural property of the nanoparticles were checked by conducting N2 physisorption experiments on the nanoparticles at 77 K. AMD-treatment performance of the fabricated membranes was evaluated in a dead-end filtration cell using a synthetic acid mine drainage (AMD) solution prepared by dissolving a known amount of MgCl2, MnCl2 4H2O, Na2SO4, Al(NO3)3, Fe(NO3)3 9H2O, and Ca2OH2 in deionized water. Results from the N2 physisorption experiments on the nanoparticles at 77 K showed a reduction in surface area and increase in pore diameter of the nanoparticles after functionalization. Performance of the membranes during AMD treatment shows that, at 4 bar, a 10% fSSOD/Psf membrane displayed improved heavy metal rejection >50% for all heavy metals considered, expect the SSOD-loaded membrane that showed a rejection <13% (except for Al3+ 89%). In addition, coating the membranes with a PVA layer improved the antifouling property of the membranes. The effects of multiple PVA coating and behaviour of the membranes during real AMD are not reported in this study, these should be investigated in a future study. Therefore, the newly developed functionalized SSOD infused Psf membranes could find applications in the treatment of AMD or for the removal of heavy metals from wastewater.The University of the Witwatersrand and the Council of Scientific and Industrial Research (CSIR).https://www.mdpi.com/journal/membranesam2022Chemical Engineerin

Performance evaluation of green adsorbent (neem leaf powder) for desulfurization of petroleum distillate

The release of sulfur-containing compounds during direct combustion of diesel fuel has caused environment issues which require urgent attention. Recently, stringent environmental regulations by the Environmental Protection Agency (EPA) to minimise the total sulfur-containing compounds released into the atmosphere have intensified the research in this area. In this present study, adsorption experiments in batch mode were conducted using an activated green adsorbent (Neem leaves powder) to reduce the amount of dibenzothiophene (DBT) in a synthetic oil. The synthetic oil was prepared by dissolving 0.1 g of dibenzothiophene (DBT) in 100 mL of hexane. Various analytical techniques were used such as; Scanning electron microscopy (SEM) to check the morphological structure of the adsorbent. Nitrogen adsorption and desorption experiments (Brunauer-Emmett-Teller, BET) at 77 K were used to check the surface area, pore size and pore volume of the adsorbent. N2 physio-sorption at 77 K before and after adsorption showed adsorption of DBT molecules onto the surface of the adsorbent after adsorption experiment. The results showed about 65.78 % removal of DBT at temperature of 30o C and adsorbent amount of 0.8 g. Therefore, neem leave powder could be an alternative cheap adsorbent to reduce the concentration of organo-sulfur compound in petroleum distillates. This may offer new perception into the development and application of green materials in sustainable, innovative and effective waste management and abatement of environmental pollution.L’Oréal-UNESCO foundation for Women in Science, Sub-Saharan African Fellowship.http://www.cetjournal.itpm2021Chemical Engineerin

Membrane purification techniques for recovery of succinic acid obtained from fermentation broth during bioconversion of lignocellulosic biomass : current advances and future perspectives

Recently, the bioconversion of biomass into biofuels and biocommodities has received significant attention. Although green technologies for biofuel and biocommodity production are advancing, the productivity and yield from these techniques are low. Over the past years, various recovery and purification techniques have been developed and successfully employed to improve these technologies. However, these technologies still require improvement regarding the energyconsumption-related costs, low yield and product purity. In the context of sustainable green production, this review presents a broad review of membrane purification technologies/methods for succinic acid, a biocommodity obtained from lignocellulosic biomass. In addition, a short overview of the global market for sustainable green chemistry and circular economy systems or zero waste approach towards a sustainable waste management is presented. Succinic acid, the available feedstocks for its production and its industrial applications are also highlighted. Downstream separation processes of succinic acid and the current studies on different downstream processing techniques are critically reviewed. Furthermore, critical analysis of membrane-based downstream processes of succinic acid production from fermentation broth is highlighted. A short review of the integrated-membrane-based process is discussed, as well, because integrating “one-pot” lignocellulosic bioconversion to succinic acid with downstream separation processing is considered a critical issue to address. In conclusion, speculations on outlook are suggested.The National Research Foundation of South Africa.https://www.mdpi.com/journal/sustainabilityChemical Engineerin

Blended polysulfone/polyethersulfone (PSF/PES) membrane with enhanced antifouling property for separation of succinate from organic acids from fermentation broth

Please read abstract in the article.The National Research Foundation of South Africa (NRF)https://pubs.acs.org/journal/ascecg2022-09-13hj2022Chemical Engineerin