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Integration of microwave co-torrefaction with helical lift for pellet fuel production

  • Kah Yein Cheong , Sieng Huat Kong , Rock Keey Liew , Chee Chung Wong , Chee Swee Wong , Heng Jong Ngu and Peter Nai Yuh Yek EMAIL logo
Published/Copyright: April 19, 2022
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Green Processing and Synthesis
From the journal Green Processing and Synthesis Volume 11 Issue 1

Abstract

The heating performance of empty fruit bunch pellets (EFBPs) has been limited by its low energy density, high moisture, and ash content. Hence, microwave co-torrefaction (MCT) was performed with microwave heating unto waste oil mixed EFBP to produce high-energy biofuel. However, the non-homogeneous electromagnetic fields distribution in the microwave cavity results in an uneven heating behavior, producing the hot and cold spots. Hence, MCT coupled with helical lift was examined for its potential to improve heat distribution. The effect of temperature and types of waste oil on the proximate analysis and surface properties were studied. In comparison to the conventional torrefaction using a furnace (>30 min), MCT provided rapid heating (50–80°C·min−1) and a shorter process time (10 min). The use of helical lift with 2-dimensional movement – rotational (24 rpm·min−1) and vertical motion (5 cm·min−1) simultaneously, distributed microwave radiation uniformly for rapid heating. The proximate analysis demonstrated that the ash content was reduced from 8 to 3 wt%, and the highest fuel ratio of 2.0 was achieved. Additionally, the highly porous structure of EFBP biochar can act as an activated carbon precursor. MCT coupled with helical lift represents a promising approach to prevent hot spots during microwave heating.

Keywords: microwave; torrefaction; empty fruit bunch; helical lift; hot spot

1 Introduction

Torrefaction is a thermal pre-treatment method under an inert environment, typically used to enhance biomass value as co-firing materials, focusing on the biochar yield and energy generation at a lower temperature of 200–300°C for several minutes or hours. Microwave heating could be integrated with the torrefaction process to improve the overall process efficiency and product quality [1]. However, there is lacking detailed understanding of the mechanism of microwave heating during torrefaction. Hence, a significant attribute of thermochemical processing of biomass in microwave co-torrefaction (MCT) system is essential to improve the storage period and energy value of torrefied product [2,3]. Microwave heating has demonstrated several advantages in terms of volumetric and dielectric heating by electromagnetic radiation in bulk conditions.

MCT is a relatively new and underexplored research, especially from the standpoint of microwave heating and reactor design that involve higher temperatures of heating. Most of the literature was focused on the conventional heating of torrefaction whereas research for microwave heating in torrefaction is limited [4]. The studies of torrefaction using conventional heating were usually performed under several process parameters such as time, temperature, and constituents of feedstock, while the microwave power and irradiation time were process variables reported in MCT in the existing studies [2,5,6,7]. However, torrefaction temperature distribution and weight reduction compensation methods are rarely reported in the literature [8].

Several challenges have been found in MCT related to the uneven temperatures that occurred (Figure 1a) and overheating at the edge due to the non-uniform distribution in the electromagnetic field that needs to be overcome to fully utilize microwave heating in torrefaction. The existing studies on the distribution of microwave heating in the reactor were reported on the size, shape, surface condition of the cavity [9], multi-combination of magnetron [10], magnetron operating frequency [11], frequency distribution [12], and incorporation of mode stirrer and rotational table [13,14,15] to improve the uniformity of microwave heating. The variation in dielectric and proximate properties of the material with the temperature changes [16,17], load geometry [18], and sample location inside the microwave cavity could also be the significant parameters to affect the electromagnetic fields distribution and microwave heating behavior. The electromagnetic field distribution is critical for controlling microwave heating [17] and avoiding local hot and cold spots [18].

Figure 1 Empty fruit bunch pellet: (a) after heating in static condition and (b) after even heating in 2D motion.
Figure 1

Empty fruit bunch pellet: (a) after heating in static condition and (b) after even heating in 2D motion.

To further improve biofuel quality and waste minimization, co-torrefaction of different feedstocks shows promising prospects and is highly feasible. Co-torrefaction of heterogeneous feedstocks (solid and liquid phases) or wet torrefaction enhances grindability, hydrophobicity, and fuel properties of the torrefied products, significantly removing more ash by sample demineralization [19]. In addition, higher torrefaction temperature and liquid feedstock fraction were found to contribute toward a positive synergistic effect [20].

Estimating the correct temperature within the microwaved biomass material is also critical to the advancement of microwave technology in the field of biomass torrefaction. Furthermore, to achieve quality, uniformity, and sustainability in product, the researcher has to ensure torrefaction that is performed fast and thoroughly to minimize the loss of weight due to the over decomposition of biomass material under the microwave. Therefore, better temperature uniformity as shown in Figure 1b is critical for ensuring product quality and reducing energy consumption. The present study aims to improve the microwave heating uniformity via the installation of a helical lift to investigate the effects of microwave heating temperature and the blending of waste oils.

2 Material and methods

2.1 Materials preparation

Empty fruit bunch pellets (EFBPs) were collected from a palm oil mill in Sarawak, Malaysia. The pellets with a diameter of 8 mm and length of 5–20 mm were air-dried (DEFBP) before being subjected into MCT. The samples were shredded into powder and sieved for further analyses. Used cooking oil (UCO) from fast food restaurant in Sibu, Sarawak, Malaysia, was filtered and stored in a dark sealed bottle before mixing with EFBP.

2.2 Experimental setup of MCT

As shown in Figure 2, the schematic diagram of the MCT consists of eight major components: (i) magnetron with a fixed power of 1,000 W, (ii) microwave cavity (110 mm × 110 mm × 110 mm), (iii) 250 mL quartz reactor, (iv) waveguide, (v) type K thermocouple, (vi) multi-range temperature controller, (vii) helical lift, and (viii) a borosilicate condenser set. A flat quartz glass was employed to isolate the waveguide from the microwave cavity. The helical lift was tuned to run at 24 rpm with 5 cm·min−1 vertical movement to achieve an even microwave radiation to the EFBP. The temperature of torrefaction was set using a temperature controller and recorded via a thermocouple.

Figure 2 Schematic diagram of MCT system.
Figure 2

Schematic diagram of MCT system.

The helical lift was used to enable rotational and translational motion to work simultaneously to improve microwave heating distribution. The MCT was conducted under a self-purging inert atmosphere (limited oxygen), in which no nitrogen gas purging was required. Hence, it is more economically feasible compared with the conventional torrefaction process that requires continuous purging of nitrogen gas. 50 g of EFBP was added to the quartz reactor and then heated to a temperature range of 200–250°C and 250–300°C for 30 s. EFBP was then mixed with UCO before being subjected to a torrefaction procedure. The temperature profile of torrefaction experiments (raw EFBP, DEFBP, and EFBP/UCO) was studied by recording the temperature. The torrefied pellets were cooled and stored in a desiccator for further analysis.

2.3 Characterization of torrefied products

The proximate analysis was conducted referring to ASTM D 5142-02a with an electric furnace and analytical balance. The fuel ratio of the torrefied product was then calculated by dividing fixed carbon over volatile matter. The surface morphology of raw and torrefied pellets was examined using a JOEL-6000 scanning electron microscope (SEM) which operates at an accelerating voltage of 15 kV. The oxygen bomb calorimeter (LECO, AC-350) was used to calculate the calorific value of the sample according to ASTM D5865 [21].

3 Results and discussion

3.1 Temperature profile of microwave co-torrefaction

Figure 3 compares the temperature profile of microwave torrefaction (MT) and MCT. The process of microwave heating can be divided into three stages: (1) drying stage to remove moisture content, (2) further heating stage, and (3) torrefaction stage. The temperature profile was taken from the initial EFBP temperature (25°C) until the maximum torrefaction temperature of 300°C.

Figure 3 Temperature profile of microwave torrefaction and microwave co-torrefaction.
Figure 3

Temperature profile of microwave torrefaction and microwave co-torrefaction.

MT of EFBP shows high heating rate of 80°C·min−1 till 100°C in the first 60 s and then reduced to 10°C·min−1 from 100°C to 250°C as the biomass has low microwave absorption efficiency after all moisture has been released but increased to 50°C·min−1 from 250°C to 300°C. While MCT also shows a relatively low heating rate of 30°C·min−1 to reach 100°C, further achieved to 150°C with 12°C·min−1 heating rate, and shows a higher heating rate of 80°C·min−1 from 150°C to 300°C.

The high heating rate observed at the beginning of both MT and MCT could be attributed to the microwave heating of water in the form of moisture, where water is generally known as a strong microwave absorbent [22]. Previous studies [5,6] also exhibited a similar trend in the temperature profile of samples, especially on a small plateau region around 100°C which corresponded to the time spent in the removal of moisture from the biomass.

MT shows a lower heating rate between 100°C and 250°C was contributed by the relatively low dielectric constant and the loss factor of EFBP [22]. Then, the heating rate was increased to 50°C·min−1 from 250°C to 300°C due to the exothermic torrefaction stage and changes in biomass to carbon structure [23,24]. However, the additional UCO in MCT has reduced the de-volatilization temperature to cause a rapid increase in the heating rate (80°C·min−1) at about 150°C [25,26].

3.2 Characterization of raw EFBP and torrefied products

3.2.1 Proximate analysis, fuel ratio, and higher heating value

Table 1 shows the proximate analysis of raw EFBP and torrefied EFBP. Raw EFBP showed a high content of moisture (15 wt%) that caused the fungus to spread among the EFBP during the storage period. High volatile matter (62 wt%), ash content (8 wt%), and low fixed carbon content (15 wt%) correspond to the lower heating value of EFBP, which also lead to severe fouling, slagging, and ash meltdown during combustion [27].

Table 1

Proximate analysis and fuel ratio of raw EFBP and torrefied products

Temperature Raw EFBP Microwave torrefaction Microwave co-torrefaction
200–250°C 250–300°C 200–250°C 250–300°C
Moisture content (wt%) 15 4 1 2 1
Volatile matter (wt%) 62 52 33 49 33
aFixed carbon (wt%) 15 36 58 44 63
Ash (wt%) 8 8 8 5 3
bFuel ratio 0.2 0.7 1.8 0.9 1.9
Calorific value (mJ kg−1) 17 19 22 23 25

aFixed carbon = 100 wt% – moisture – volatile matter – ash.

bFuel ratio = fixed carbon/volatile matter.

As the temperature increased from 200°C to 250°C, the volatile matter of torrefied EFBP from MT and MCT decreased progressively to 52 and 49 wt%, respectively, whereas the fixed carbon increased to 36 and 44 wt%, respectively. This trend was predicted as the increase in temperature promoted the partial decomposition of the lignocellulose and the removal of volatile matter enriched the fixed carbon [28]. However, MCT shows a significant increase of fixed carbon to 63 wt% and reduces the ash content to 3 wt% at a temperature range of 250–300°C when compared with MT. This indicates that the addition of waste oil increases the de-volatilization rate and also enhances the collapsing of organic materials to produce fixed carbon. Hence, the hydrocarbon chain of waste oil supplies the additive energy [29,30,31] to the EFBP to compensate for the weight loss and increase the heating energy of EFBP as a solid fuel for the boiler.

The fuel ratio of the MCT increased with the torrefaction temperature in line with the increase in fixed carbon and the decrease in a volatile matter of the torrefied products. As the temperature increased from 200 to 250°C, the fuel ratio of torrefied EFBP from MT and MCT increased to 0.7 and 0.9, respectively. MT and MCT obtained the highest fuel ratio of 1.8 and 1.9, respectively, at 300°C. The enhancement in fuel characteristics was further monitored through the calorific value recorded. MT and MCT torrefied EFBP achieved the highest calorific value of 22 and 25 mJ·kg−1 at 250–300°C, respectively. Thus, the addition of the UCO coupled with the increase in torrefaction temperature was found to significantly improve the fuel characteristics of the torrefied products through the contribution of higher fixed carbon content.

3.2.2 Surface morphology

The surface texture of the raw EFBP was rough, uneven, and undulating as shown in Figure 4. The disorder of cross-section shown in Figure 4a might be resulted from the cutting effect during sample preparation. Besides that, Figure 4b shows that the EFBP surface was covered with lump structures that could be attributed to silica [32]. Figure 4c shows the magnified EFBP surface at 1,000 times, and it can be observed that the silica is present as sphere objects within the surface of EFBP.

Figure 4 Comparison of surface morphology of raw EFBP: (a) cross section, (b) surface, and (c) silica body.
Figure 4

Comparison of surface morphology of raw EFBP: (a) cross section, (b) surface, and (c) silica body.

Figure 5 shows the comparison of the surface texture of MCT of EFBP at 200‒250°C and 250‒300°C, and with or without waste oil added. The SEM images of Figure 5a and b showed more opened pores with the presence of waste oil at a temperature of 200°C. As a result, more silica body was released thus creating more tiny rudimentary pores [33]. It has also been observed that the torrefied char obtained at a temperature of 300°C in Figure 5c showed a uniform honeycomb structure which is normally reported [34,35]. Moreover, patches of crack and cell wall breakdown have been observed in Figure 5d when waste oil is applied. However, higher temperatures (300°C) produced better-torrefied products via the decomposition of hemicellulose and cellulose of EFBP into carbon.

Figure 5 Surface morphology of torrefied EFBP: (a) 200°C of MT, (b) 200°C of MCT, (c) 300°C of MT, and (d) 300°C of MCT.
Figure 5

Surface morphology of torrefied EFBP: (a) 200°C of MT, (b) 200°C of MCT, (c) 300°C of MT, and (d) 300°C of MCT.

4 Conclusions

Microwave co-torrefaction (MCT) has shown a high energy-efficient approach in enhancing empty fruit bunch pellet (EFBP) into higher energy co-firing fuel. Integration of microwave and used cooking oil has torrefied the EFBP at a rapid volumetric heating rate up to 80°C·min−1 and short torrefaction time (10 min). The helical lift also provides 2D motion with better microwave heat distribution. Torrefied EFBP by MCT at 250–300°C has produced high fixed carbon content (63 wt%), low volatile matter (33 wt%), and low ash content (3 wt%). The differences shown in the surface morphology of EFBP before and after MCT were attributed to the removal of the silica body. The results have proven that the utilization of MCT can generate an economically more viable and sustainable torrefaction process. Evidence of synergy between two heterogeneous feedstocks observed in temperature profiles may provide an insight into a more systematic approach to co-torrefaction. A reliable reaction kinetic data of mixing the heterogeneous feedstocks in different mass ratios can contribute to the designing and operation of industrial systems, promising improved overall process efficiency

Acknowledgment

The authors acknowledge the financial support from the University of Technology Sarawak for the conduct of the research under the University Grant Scheme (Project No. UCTS/RESEARCH/2/2020/07).

  1. Funding information: University of Technology Sarawak for the conduct of the research under the University Grant Q3 Scheme (Project No. UCTS/RESEARCH/2/2020/07).

  2. Author contributions: Kah Yein Cheong: writing – review and editing; Sieng-Huat Kong: writing – review and editing; Rock Keey Liew: writing – review and editing; Chee Chung Wong: writing – review and editing; Chee Swee Wong: writing – review and editing; Heng Jong Ngu: writing – review and editing; Peter Nai Yuh Yek: data curation, methodology, investigation, formal analysis, writing – original draft.

  3. Conflict of interest: One of the authors (Rock Keey Liew) is a member of the Editorial Board of Green Processing and Synthesis.

References

[1] Siritheerasas P, Waiyanate P, Sekiguchi H, Kodama S. Microwave torrefaction of moist municipal solid waste (MSW) pellets with the addition of char from agricultural residues. 11th Pure and Applied Chemistry International Conference, PACCON 2017; 2017. p. 156–60.10.4028/www.scientific.net/KEM.757.156Search in Google Scholar

[2] Huang Y-F, Cheng P-H, Chiueh P-T, Lo S-L. Leucaena biochar produced by microwave torrefaction: fuel properties and energy efficiency. Appl Energy. 2017;204:1018–25.10.1016/j.apenergy.2017.03.007Search in Google Scholar

[3] Tumuluru JS, Kremer T, Wright CT, Boardman RD. Proximate and ultimate compositional changes in corn stover during torrrefaction using thermogravimetric analyzer and microwaves. American Society of Agricultural and Biological Engineers Annual International Meeting 2012, Dallas, TX; 2012. p. 1348–65.Search in Google Scholar

[4] Nam H, Capareda S. Experimental investigation of torrefaction of two agricultural wastes of different composition using RSM (response surface methodology). Energy. 2015;91:507–16.10.1016/j.energy.2015.08.064Search in Google Scholar

[5] Natarajan P, Suriapparao DV, Vinu R. Microwave torrefaction of Prosopis juliflora: experimental and modeling study. Fuel Process Technol. 2018;172:86–96.10.1016/j.fuproc.2017.12.007Search in Google Scholar

[6] Iroba KL, Baik O-D, Tabil LG. Torrefaction of biomass from municipal solid waste fractions I: temperature profiles, moisture content, energy consumption, mass yield, and thermochemical properties. Biomass Bioenerg. 2017;105:320–30.10.1016/j.biombioe.2017.07.009Search in Google Scholar

[7] Iroba KL, Baik O-D, Tabil LG. Torrefaction of biomass from municipal solid waste fractions II: grindability characteristics, higher heating value, pelletability and moisture adsorption. Biomass Bioenerg. 2017;106:8–20.10.1016/j.biombioe.2017.08.008Search in Google Scholar

[8] Ren S, Lei H, Wang L, Yadavalli G, Liu Y, Julson J. The integrated process of microwave torrefaction and pyrolysis of corn stover for biofuel production. J Anal Appl Pyrol. 2014;108:248–53.10.1016/j.jaap.2014.04.008Search in Google Scholar

[9] Binner E, Mediero-Munoyerro M, Huddle T, Kingman S, Dodds C, Dimitrakis G, et al. Factors affecting the microwave coking of coals and the implications on microwave cavity design. Fuel Process Technol. 2014;125:8–17.10.1016/j.fuproc.2014.03.006Search in Google Scholar

[10] Puangsuwan K, Tongurai C, Chongcheawchamnan M. Design of microwave heating continuous belt system for palm fruit. Asia Pac Mic. 2015;3:1–3.10.1109/APMC.2015.7413502Search in Google Scholar

[11] Soltysiak M, Erle U, Celuch M. Influence of the magnetron operating frequency on the results of microwave heating. 2010 IEEE MTT-S International Microwave Symposium; 2010. p. 1–1.10.1109/MWSYM.2010.5516115Search in Google Scholar

[12] Luan D, Wang Y, Tang J, Jain D. Frequency distribution in domestic microwave ovens and its influence on heating pattern. J Food Sci. 2017;82:429–36.10.1111/1750-3841.13587Search in Google Scholar PubMed

[13] Halim SA, Swithenbank J. Simulation study of parameters influencing microwave heating of biomass. J Energy Inst. 2018;92:1191–212.10.1016/j.joei.2018.05.010Search in Google Scholar

[14] Cuccurullo G, Giordano L, Metallo A, Cinquanta L. Influence of mode stirrer and air renewal on controlled microwave drying of sliced zucchini. Biosyst Eng. 2017;158:95–101.10.1016/j.biosystemseng.2017.03.012Search in Google Scholar

[15] Chen J, Pitchai K, Birla S, Jones D, Negahban M, Subbiah J. Modeling heat and mass transport during microwave heating of frozen food rotating on a turntable. Food Bioprod Process. 2016;99:116–27.10.1016/j.fbp.2016.04.009Search in Google Scholar

[16] Salvi D, Ortego J, Arauz C, Sabliov CM, Boldor D. Experimental study of the effect of dielectric and physical properties on temperature distribution in fluids during continuous flow microwave heating. J Food Eng. 2009;93:149–57.10.1016/j.jfoodeng.2009.01.009Search in Google Scholar

[17] Catalá-Civera JM, Canós AJ, Plaza-González P, Gutiérrez JD, García-Baños B, Peñaranda-Foix FL. Dynamic measurement of dielectric properties of materials at high temperature during microwave heating in a dual mode cylindrical cavity. IEEE T Microw Theory. 2015;63:2905–14.10.1109/TMTT.2015.2453263Search in Google Scholar

[18] Ciacci T, Galgano A, Di Blasi C. Numerical simulation of the electromagnetic field and the heat and mass transfer processes during microwave-induced pyrolysis of a wood block. Chem Eng Sci. 2010;65:4117–33.10.1016/j.ces.2010.04.039Search in Google Scholar

[19] Sh L, Lee BH, Jeong TY, Jeon CH. Effects of different pretreatment methods on the grindability of pitch pine sawdust biomass and its blends with coal. J Mech Sci Technol. 2020;34:2235–43.10.1007/s12206-020-0445-4Search in Google Scholar

[20] Gouws SM, Carrier M, Bunt JR, Neomagus HWJP. Co-pyrolysis of coal and raw/torrefied biomass: A review on chemistry, kinetics and implementation. Renew Sust Energ Rev. 2021;135:110189.10.1016/j.rser.2020.110189Search in Google Scholar

[21] Parr IC. Oxygen bomb calorimeter: operating instruction manual; 2010. p. 89.Search in Google Scholar

[22] Omar R, Idris A, Yunus R, Khalid K, Aida Isma MI. Characterization of empty fruit bunch for microwave-assisted pyrolysis. Fuel. 2011;90:1536–44.10.1016/j.fuel.2011.01.023Search in Google Scholar

[23] Ge S, Yek PNY, Cheng YW, Xia C, Wan Mahari WA, Liew RK, et al. Progress in microwave pyrolysis conversion of agricultural waste to value-added biofuels: a batch to continuous approach. Renew Sust Energ Rev. 2021;135:110189.10.1016/j.rser.2020.110148Search in Google Scholar

[24] Yek PNY, Peng W, Wong CC, Liew RK, Ho YL, Wan Mahari WA, et al. Engineered biochar via microwave CO2 and steam pyrolysis to treat carcinogenic Congo red dye. J Hazard Mater. 2020;395:122636.10.1016/j.jhazmat.2020.122636Search in Google Scholar PubMed

[25] Lam SS, Tsang YF, Yek PNY, Liew RK, Osman MS, Peng W, et al. Co-processing of oil palm waste and waste oil via microwave co-torrefaction: a waste reduction approach for producing solid fuel product with improved properties. Process Saf Environ. 2019;128:30–35.10.1016/j.psep.2019.05.034Search in Google Scholar

[26] Yek PNY, Chen X, Peng W, Liew RK, Cheng CK, Sonne C, et al. Microwave co-torrefaction of waste oil and biomass pellets for simultaneous recovery of waste and co-firing fuel. Renew Sust Energ Rev. 2021;152:111699.10.1016/j.rser.2021.111699Search in Google Scholar

[27] Madhiyanon T, Sathitruangsak P, Sungworagarn S, Pipatmanomai S, Tia S. A pilot-scale investigation of ash and deposition formation during oil-palm empty-fruit-bunch (EFB) combustion. Fuel Process Technol. 2012;96:250–64.10.1016/j.fuproc.2011.12.020Search in Google Scholar

[28] Liew RK, Nam WL, Chong MY, Phang XY, Su MH, Yek PNY, et al. Oil palm waste: an abundant and promising feedstock for microwave pyrolysis conversion into good quality biochar with potential multi-applications. Process Saf Environ. 2018;115:57–69.10.1016/j.psep.2017.10.005Search in Google Scholar

[29] Lam SS, Liew RK, Cheng CK, Chase HA. Catalytic microwave pyrolysis of waste engine oil using metallic pyrolysis char. Appl Catal B Environ. 2015;176–7:601–17.10.1016/j.apcatb.2015.04.014Search in Google Scholar

[30] Lam SS, Russell AD, Lee CL, Chase HA. Microwave-heated pyrolysis of waste automotive engine oil: Influence of operation parameters on the yield, composition, and fuel properties of pyrolysis oil. Fuel. 2012;92:327–39.10.1016/j.fuel.2011.07.027Search in Google Scholar

[31] Tangy A, Pulidindi IN, Perkas N, Gedanken A. Continuous flow through a microwave oven for the large-scale production of biodiesel from waste cooking oil. Bioresour Technol. 2017;224:333–41.10.1016/j.biortech.2016.10.068Search in Google Scholar PubMed

[32] Baharuddin AS, Sulaiman A, Kim DH, Mokhtar MN, Hassan MA, Wakisaka M, et al. Selective component degradation of oil palm empty fruit bunches (OPEFB) using high-pressure steam. Biomass Bioenerg. 2013;55:268–75.10.1016/j.biombioe.2013.02.013Search in Google Scholar

[33] Hameed BH, Tan IAW, Ahmad AL. Preparation of oil palm empty fruit bunch-based activated carbon for removal of 2,4,6-trichlorophenol: optimization using response surface methodology. J Hazard Mater. 2009;164:1316–24.10.1016/j.jhazmat.2008.09.042Search in Google Scholar PubMed

[34] Hameed BH, Daud FBM. Adsorption studies of basic dye on activated carbon derived from agricultural waste: hevea brasiliensis seed coat. Chem Eng J. 2008;139:48–55.10.1016/j.cej.2007.07.089Search in Google Scholar

[35] Amosa MK. Process optimization of Mn and H2S removals from POME using an enhanced empty fruit bunch (EFB)-based adsorbent produced by pyrolysis. Environ Nanotechnol Monit Manag. 2015;4:93–105.10.1016/j.enmm.2015.09.002Search in Google Scholar
Received: 2021-12-31
Revised: 2022-03-09
Accepted: 2022-03-23
Published Online: 2022-04-19

© 2022 Kah Yein Cheong et al., published by De Gruyter

This work is licensed under the Creative Commons Attribution 4.0 International License.

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  46. Phosphorus removal from aqueous solution by adsorption using wetland-based biochar: Batch experiment
  47. A low-cost and eco-friendly fabrication of an MCDI-utilized PVA/SSA/GA cation exchange membrane
  48. Synthesis, microstructure, and phase transition characteristics of Gd/Nd-doped nano VO2 powders
  49. Biomediated synthesis of ZnO quantum dots decorated attapulgite nanocomposites for improved antibacterial properties
  50. Preparation of metal–organic frameworks by microwave-assisted ball milling for the removal of CR from wastewater
  51. A green approach in the biological base oil process
  52. A cost-effective and eco-friendly biosorption technology for complete removal of nickel ions from an aqueous solution: Optimization of process variables
  53. Protective role of Spirulina platensis liquid extract against salinity stress effects on Triticum aestivum L.
  54. Comprehensive physical and chemical characterization highlights the uniqueness of enzymatic gelatin in terms of surface properties
  55. Effectiveness of different accelerated green synthesis methods in zinc oxide nanoparticles using red pepper extract: Synthesis and characterization
  56. Blueprinting morpho-anatomical episodes via green silver nanoparticles foliation
  57. A numerical study on the effects of bowl and nozzle geometry on performances of an engine fueled with diesel or bio-diesel fuels
  58. Liquid-phase hydrogenation of carbon tetrachloride catalyzed by three-dimensional graphene-supported palladium catalyst
  59. The catalytic performance of acid-modified Hβ molecular sieves for environmentally friendly acylation of 2-methylnaphthalene
  60. A study of the precipitation of cerium oxide synthesized from rare earth sources used as the catalyst for biodiesel production
  61. Larvicidal potential of Cipadessa baccifera leaf extract-synthesized zinc nanoparticles against three major mosquito vectors
  62. Fabrication of green nanoinsecticides from agri-waste of corn silk and its larvicidal and antibiofilm properties
  63. Palladium-mediated base-free and solvent-free synthesis of aromatic azo compounds from anilines catalyzed by copper acetate
  64. Study on the functionalization of activated carbon and the effect of binder toward capacitive deionization application
  65. Co-chlorination of low-density polyethylene in paraffin: An intensified green process alternative to conventional solvent-based chlorination
  66. Antioxidant and photocatalytic properties of zinc oxide nanoparticles phyto-fabricated using the aqueous leaf extract of Sida acuta
  67. Recovery of cobalt from spent lithium-ion battery cathode materials by using choline chloride-based deep eutectic solvent
  68. Synthesis of insoluble sulfur and development of green technology based on Aspen Plus simulation
  69. Photodegradation of methyl orange under solar irradiation on Fe-doped ZnO nanoparticles synthesized using wild olive leaf extract
  70. A facile and universal method to purify silica from natural sand
  71. Green synthesis of silver nanoparticles using Atalantia monophylla: A potential eco-friendly agent for controlling blood-sucking vectors
  72. Endophytic bacterial strain, Brevibacillus brevis-mediated green synthesis of copper oxide nanoparticles, characterization, antifungal, in vitro cytotoxicity, and larvicidal activity
  73. Off-gas detection and treatment for green air-plasma process
  74. Ultrasonic-assisted food grade nanoemulsion preparation from clove bud essential oil and evaluation of its antioxidant and antibacterial activity
  75. Construction of mercury ion fluorescence system in water samples and art materials and fluorescence detection method for rhodamine B derivatives
  76. Hydroxyapatite/TPU/PLA nanocomposites: Morphological, dynamic-mechanical, and thermal study
  77. Potential of anaerobic co-digestion of acidic fruit processing waste and waste-activated sludge for biogas production
  78. Synthesis and characterization of ZnO–TiO2–chitosan–escin metallic nanocomposites: Evaluation of their antimicrobial and anticancer activities
  79. Nitrogen removal characteristics of wet–dry alternative constructed wetlands
  80. Structural properties and reactivity variations of wheat straw char catalysts in volatile reforming
  81. Microfluidic plasma: Novel process intensification strategy
  82. Antibacterial and photocatalytic activity of visible-light-induced synthesized gold nanoparticles by using Lantana camara flower extract
  83. Antimicrobial edible materials via nano-modifications for food safety applications
  84. Biosynthesis of nano-curcumin/nano-selenium composite and their potentialities as bactericides against fish-borne pathogens
  85. Exploring the effect of silver nanoparticles on gene expression in colon cancer cell line HCT116
  86. Chemical synthesis, characterization, and dose optimization of chitosan-based nanoparticles of clodinofop propargyl and fenoxaprop-p-ethyl for management of Phalaris minor (little seed canary grass): First report
  87. Double [3 + 2] cycloadditions for diastereoselective synthesis of spirooxindole pyrrolizidines
  88. Green synthesis of silver nanoparticles and their antibacterial activities
  89. Review Articles
  90. A comprehensive review on green synthesis of titanium dioxide nanoparticles and their diverse biomedical applications
  91. Applications of polyaniline-impregnated silica gel-based nanocomposites in wastewater treatment as an efficient adsorbent of some important organic dyes
  92. Green synthesis of nano-propolis and nanoparticles (Se and Ag) from ethanolic extract of propolis, their biochemical characterization: A review
  93. Advances in novel activation methods to perform green organic synthesis using recyclable heteropolyacid catalysis
  94. Limitations of nanomaterials insights in green chemistry sustainable route: Review on novel applications
  95. Special Issue: Use of magnetic resonance in profiling bioactive metabolites and its applications (Guest Editors: Plalanoivel Velmurugan et al.)
  96. Stomach-affecting intestinal parasites as a precursor model of Pheretima posthuma treated with anthelmintic drug from Dodonaea viscosa Linn.
  97. Anti-asthmatic activity of Saudi herbal composites from plants Bacopa monnieri and Euphorbia hirta on Guinea pigs
  98. Embedding green synthesized zinc oxide nanoparticles in cotton fabrics and assessment of their antibacterial wound healing and cytotoxic properties: An eco-friendly approach
  99. Synthetic pathway of 2-fluoro-N,N-diphenylbenzamide with opto-electrical properties: NMR, FT-IR, UV-Vis spectroscopic, and DFT computational studies of the first-order nonlinear optical organic single crystal
https://doi.org/10.1515/gps-2022-0041
Keywords for this article
microwave; torrefaction; empty fruit bunch; helical lift; hot spot
Creative Commons
BY 4.0

Articles in the same Issue

  1. Research Articles
  2. Kinetic study on the reaction between Incoloy 825 alloy and low-fluoride slag for electroslag remelting
  3. Black pepper (Piper nigrum) fruit-based gold nanoparticles (BP-AuNPs): Synthesis, characterization, biological activities, and catalytic applications – A green approach
  4. Protective role of foliar application of green-synthesized silver nanoparticles against wheat stripe rust disease caused by Puccinia striiformis
  5. Effects of nitrogen and phosphorus on Microcystis aeruginosa growth and microcystin production
  6. Efficient degradation of methyl orange and methylene blue in aqueous solution using a novel Fenton-like catalyst of CuCo-ZIFs
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  8. Efficient pilot-scale synthesis of the key cefonicid intermediate at room temperature
  9. Synthesis and characterization of noble metal/metal oxide nanoparticles and their potential antidiabetic effect on biochemical parameters and wound healing
  10. Regioselectivity in the reaction of 5-amino-3-anilino-1H-pyrazole-4-carbonitrile with cinnamonitriles and enaminones: Synthesis of functionally substituted pyrazolo[1,5-a]pyrimidine derivatives
  11. A numerical study on the in-nozzle cavitating flow and near-field atomization of cylindrical, V-type, and Y-type intersecting hole nozzles using the LES-VOF method
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  14. Sonochemical synthesis of protein microcapsules loaded with traditional Chinese herb extracts
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  17. Superior photocatalytic degradation performance for gaseous toluene by 3D g-C3N4-reduced graphene oxide gels
  18. Catalytic performance of Na/Ca-based fluxes for coal char gasification
  19. Slow pyrolysis of waste navel orange peels with metal oxide catalysts to produce high-grade bio-oil
  20. Development and butyrylcholinesterase/monoamine oxidase inhibition potential of PVA-Berberis lycium nanofibers
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  22. Green synthesis, characterization, cytotoxicity, and antimicrobial activity of iron oxide nanoparticles using Nigella sativa seed extract
  23. Vitamin supplements enhance Spirulina platensis biomass and phytochemical contents
  24. Malachite green dye removal using ceramsite-supported nanoscale zero-valent iron in a fixed-bed reactor
  25. Green synthesis of manganese-doped superparamagnetic iron oxide nanoparticles for the effective removal of Pb(ii) from aqueous solutions
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  29. Calcium oxide addition and ultrasonic pretreatment-assisted hydrothermal carbonization of granatum for adsorption of lead
  30. Fe3O4@SiO2 nanoflakes synthesized using biogenic silica from Salacca zalacca leaf ash and the mechanistic insight into adsorption and photocatalytic wet peroxidation of dye
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  32. Synergistic in vitro anticancer actions of decorated selenium nanoparticles with fucoidan/Reishi extract against colorectal adenocarcinoma cells
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  35. Integration of microwave co-torrefaction with helical lift for pellet fuel production
  36. Cytotoxicity of green-synthesized silver nanoparticles by Adansonia digitata fruit extract against HTC116 and SW480 human colon cancer cell lines
  37. Optimization of biochar preparation process and carbon sequestration effect of pruned wolfberry branches
  38. Anticancer potential of biogenic silver nanoparticles using the stem extract of Commiphora gileadensis against human colon cancer cells
  39. Fabrication and characterization of lysine hydrochloride Cu(ii) complexes and their potential for bombing bacterial resistance
  40. First report of biocellulose production by an indigenous yeast, Pichia kudriavzevii USM-YBP2
  41. Biosynthesis and characterization of silver nanoparticles prepared using seeds of Sisymbrium irio and evaluation of their antifungal and cytotoxic activities
  42. Synthesis, characterization, and photocatalysis of a rare-earth cerium/silver/zinc oxide inorganic nanocomposite
  43. Developing a plastic cycle toward circular economy practice
  44. Fabrication of CsPb1−xMnxBr3−2xCl2x (x = 0–0.5) quantum dots for near UV photodetector application
  45. Anti-colon cancer activities of green-synthesized Moringa oleifera–AgNPs against human colon cancer cells
  46. Phosphorus removal from aqueous solution by adsorption using wetland-based biochar: Batch experiment
  47. A low-cost and eco-friendly fabrication of an MCDI-utilized PVA/SSA/GA cation exchange membrane
  48. Synthesis, microstructure, and phase transition characteristics of Gd/Nd-doped nano VO2 powders
  49. Biomediated synthesis of ZnO quantum dots decorated attapulgite nanocomposites for improved antibacterial properties
  50. Preparation of metal–organic frameworks by microwave-assisted ball milling for the removal of CR from wastewater
  51. A green approach in the biological base oil process
  52. A cost-effective and eco-friendly biosorption technology for complete removal of nickel ions from an aqueous solution: Optimization of process variables
  53. Protective role of Spirulina platensis liquid extract against salinity stress effects on Triticum aestivum L.
  54. Comprehensive physical and chemical characterization highlights the uniqueness of enzymatic gelatin in terms of surface properties
  55. Effectiveness of different accelerated green synthesis methods in zinc oxide nanoparticles using red pepper extract: Synthesis and characterization
  56. Blueprinting morpho-anatomical episodes via green silver nanoparticles foliation
  57. A numerical study on the effects of bowl and nozzle geometry on performances of an engine fueled with diesel or bio-diesel fuels
  58. Liquid-phase hydrogenation of carbon tetrachloride catalyzed by three-dimensional graphene-supported palladium catalyst
  59. The catalytic performance of acid-modified Hβ molecular sieves for environmentally friendly acylation of 2-methylnaphthalene
  60. A study of the precipitation of cerium oxide synthesized from rare earth sources used as the catalyst for biodiesel production
  61. Larvicidal potential of Cipadessa baccifera leaf extract-synthesized zinc nanoparticles against three major mosquito vectors
  62. Fabrication of green nanoinsecticides from agri-waste of corn silk and its larvicidal and antibiofilm properties
  63. Palladium-mediated base-free and solvent-free synthesis of aromatic azo compounds from anilines catalyzed by copper acetate
  64. Study on the functionalization of activated carbon and the effect of binder toward capacitive deionization application
  65. Co-chlorination of low-density polyethylene in paraffin: An intensified green process alternative to conventional solvent-based chlorination
  66. Antioxidant and photocatalytic properties of zinc oxide nanoparticles phyto-fabricated using the aqueous leaf extract of Sida acuta
  67. Recovery of cobalt from spent lithium-ion battery cathode materials by using choline chloride-based deep eutectic solvent
  68. Synthesis of insoluble sulfur and development of green technology based on Aspen Plus simulation
  69. Photodegradation of methyl orange under solar irradiation on Fe-doped ZnO nanoparticles synthesized using wild olive leaf extract
  70. A facile and universal method to purify silica from natural sand
  71. Green synthesis of silver nanoparticles using Atalantia monophylla: A potential eco-friendly agent for controlling blood-sucking vectors
  72. Endophytic bacterial strain, Brevibacillus brevis-mediated green synthesis of copper oxide nanoparticles, characterization, antifungal, in vitro cytotoxicity, and larvicidal activity
  73. Off-gas detection and treatment for green air-plasma process
  74. Ultrasonic-assisted food grade nanoemulsion preparation from clove bud essential oil and evaluation of its antioxidant and antibacterial activity
  75. Construction of mercury ion fluorescence system in water samples and art materials and fluorescence detection method for rhodamine B derivatives
  76. Hydroxyapatite/TPU/PLA nanocomposites: Morphological, dynamic-mechanical, and thermal study
  77. Potential of anaerobic co-digestion of acidic fruit processing waste and waste-activated sludge for biogas production
  78. Synthesis and characterization of ZnO–TiO2–chitosan–escin metallic nanocomposites: Evaluation of their antimicrobial and anticancer activities
  79. Nitrogen removal characteristics of wet–dry alternative constructed wetlands
  80. Structural properties and reactivity variations of wheat straw char catalysts in volatile reforming
  81. Microfluidic plasma: Novel process intensification strategy
  82. Antibacterial and photocatalytic activity of visible-light-induced synthesized gold nanoparticles by using Lantana camara flower extract
  83. Antimicrobial edible materials via nano-modifications for food safety applications
  84. Biosynthesis of nano-curcumin/nano-selenium composite and their potentialities as bactericides against fish-borne pathogens
  85. Exploring the effect of silver nanoparticles on gene expression in colon cancer cell line HCT116
  86. Chemical synthesis, characterization, and dose optimization of chitosan-based nanoparticles of clodinofop propargyl and fenoxaprop-p-ethyl for management of Phalaris minor (little seed canary grass): First report
  87. Double [3 + 2] cycloadditions for diastereoselective synthesis of spirooxindole pyrrolizidines
  88. Green synthesis of silver nanoparticles and their antibacterial activities
  89. Review Articles
  90. A comprehensive review on green synthesis of titanium dioxide nanoparticles and their diverse biomedical applications
  91. Applications of polyaniline-impregnated silica gel-based nanocomposites in wastewater treatment as an efficient adsorbent of some important organic dyes
  92. Green synthesis of nano-propolis and nanoparticles (Se and Ag) from ethanolic extract of propolis, their biochemical characterization: A review
  93. Advances in novel activation methods to perform green organic synthesis using recyclable heteropolyacid catalysis
  94. Limitations of nanomaterials insights in green chemistry sustainable route: Review on novel applications
  95. Special Issue: Use of magnetic resonance in profiling bioactive metabolites and its applications (Guest Editors: Plalanoivel Velmurugan et al.)
  96. Stomach-affecting intestinal parasites as a precursor model of Pheretima posthuma treated with anthelmintic drug from Dodonaea viscosa Linn.
  97. Anti-asthmatic activity of Saudi herbal composites from plants Bacopa monnieri and Euphorbia hirta on Guinea pigs
  98. Embedding green synthesized zinc oxide nanoparticles in cotton fabrics and assessment of their antibacterial wound healing and cytotoxic properties: An eco-friendly approach
  99. Synthetic pathway of 2-fluoro-N,N-diphenylbenzamide with opto-electrical properties: NMR, FT-IR, UV-Vis spectroscopic, and DFT computational studies of the first-order nonlinear optical organic single crystal
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