Next Article in Journal
Nanostructured p-Type Semiconductor Electrodes and Photoelectrochemistry of Their Reduction Processes
Previous Article in Journal
Black Start Strategy for PV-ESS Multi-Microgrids with Three-Phase/Single-Phase Architecture
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Energies
Volume 9
Issue 5
10.3390/en9050374
energies-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Chemical Analysis of Different Parts of Date Palm (Phoenix dactylifera L.) Using Ultimate, Proximate and Thermo-Gravimetric Techniques for Energy Production

by
Ramadan A. Nasser
1,2,*,
Mohamed Z. M. Salem
2,*,
Salim Hiziroglu
3,
Hamad A. Al-Mefarrej
1,
Ahmed S. Mohareb
2,4,
Manawwer Alam
5 and
Ibrahim M. Aref
1
1
Plant Production Department, Food and Agricultural Sciences College, King Saud University, Riyadh 11451, Saudi Arabia
2
Forestry and Wood Technology Department, Faculty of Agriculture (El-Shatby), Alexandria University, Alexandria 2154, Egypt
3
Department of Natural Resource Ecology and Management, Oklahoma State University, Stillwater, OK 74078, USA
4
College of Science, Dammam University, Dammam 31433, Saudi Arabia
5
Research Center, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
*
Authors to whom correspondence should be addressed.
Energies 2016, 9(5), 374; https://doi.org/10.3390/en9050374
Submission received: 16 March 2016 / Revised: 17 April 2016 / Accepted: 6 May 2016 / Published: 16 May 2016
Browse Figures
Versions Notes

Abstract

:
The objective of the study was to analyze chemical structure of date palm (Phoenix dactylifera L.) by employing ultimate, proximate and thermo-gravimetric techniques. Samples from different anatomical parts of date palm, namely trunk, frond base, frond midrib, leaflets, coir, fruit stem, date stone, and fruit empty bunches were considered for the experiments. Based on the findings in this work palm leaflet samples gave the highest amount of extractives content (32.9%), followed by date palm stone specimens with 31.5%. Cellulose content values of 32.8% and 47.5% were obtained for date palm stone and palm coir samples, respectively. Overall the hemicellulose contents of all samples were relatively similar to those of typical wood or non-wood lignocellulosic materials with the two exceptions of palm coir and palm leaflets. Both palm coir and palm leaflet specimens had 12.6% and 16.1% hemicellulose content. Volatile matter values of 74.3% and 87.5% were determined for leaflets and fruit empty bunch samples. The ash content of the samples ranged from 1.4% for date stone to 15.2% for palm leaflet samples. The thermal decomposition was completed below a temperature of 500 °C with an exception of those samples taken from palm leaflets. Taken together the data indicate that date palm stone and palm coir revealed could be more viable for renewable energy production than the other specimens considered in this work.

1. Introduction

New renewable resources including corncobs [1], tobacco stems [2], rice waste [3], common reed [4,5], vine prunings [6], and date palm midribs [7], are getting more and more popular as alternative materials to solid wood harvested from natural forests for bioenergy production. Date palm (Phoenix dactylifera L.), one of the most important non-wood renewable resources in the Middle East, used mainly for its fruit, fiber and as a construction material [7,8] could also be considered a raw material for energy production. The residues are used in various industries as raw materials for many applications such as lumber [9], particleboard [10,11,12], pulp and paper [13,14,15], wood-cement composites [16], wood-plastic composites [17,18], oriented strandboard [19], for the pyrolysis characteristics of the seeds [20], in briquette production [21], and for biochar production [22,23].
The Kingdom of Saudi Arabia is considered one of the pioneering countries in date palm cultivation and the annual date production is more than 970,000 tons, from the area of some 150,000 ha [24,25]. The Sukkari cultivar is an important variety cultivated in most areas of the kingdom for its high quality fruits and good economical returns to farmers. According to Agoudjil et al. [26], the main parts of the date palm tree are: (a) the palm trunk; (b) the mesh; (c) the leaves, frond base petiole, rachis, leaflets and spines; (d) the reproductive organs (spathes, fruit stalk, spikelets and pollen) and (e) a number of palm products obtained from the bunches (fruit bunch empty, fruits and seeds). In practice, under normal conditions, 6–10 bunches per palm are obtained and 12–15 new leaves are formed and trimmed annually.
Several factors affect the fuel properties of biomass feedstocks. Lignin and higher extractives contents contribute to a high heating value [27,28], while ash is considered as an undesirable material in wood for energy production [28,29]. Heating value and density of the raw material are also very important factors affecting the overall energy production output [13,28,30,31,32].
The chemical energy of a solid fuel is stored in the forms of volatiles and fixed carbon [33]. The volatiles or volatile matter content (VMC) is the portion that is driven-off as a vapor or gas by heating the fuel to 950 °C, while the remaining is known as fixed carbon (FC), excluding the ash and moisture contents. The measurement of these two forms gives what is known as a proximate analysis, which is a chemical analysis method that determines contents of VM, ash and FC. It is an excellent tool to describe and predict the heating values of a biomass [17,34,35,36,37,38,39]. In a previous work a simple equation to predict the heating values of three wood species, namely Pinus halepensis, Quercus rotundifolia and Eucaluptus saligna and three lignocellulosic wastes olive seeds, almond shells and wet straw from Southern Spain was established by using proximate analysis [34]. For a typical wood biomass without bark, the ash content is around 0.3% based on the findings of a past work [38]. In another study the ash content of a similar material ranged from 5% to 20% [39].
During the seasonal pruning of palms and with exception to the trunk, all secondary products are used for various purposes [9]. Substantial quantities of annual biomass therefore result from the seasonal pruning date palms, an essential agricultural practice in Saudi Arabia. An average of 35 kg of palm residues per tree is generated annually [40]. Accordingly, the annual wastes resulting from date palm biomass in Saudi Arabia are estimated to be approximately one million metric tons. In developing countries, most of date palm residues are burnt or left as landfill creating serious environmental pollution [21,26]. In developed countries, such wastes are used as raw material for the production of composite panels. Although there are a few literature studies that investigate the suitability of date palm residues for energy production [7,41], there is very little information on what parts of date palm tree are suitable for charcoal and energy production [41]. Abed et al. [42], tested the pyrolysis of date palm stones and stalks by thermogravimetric analysis and reported that these kinds of palm by-products constituted a significant alternative to implement a potential new renewable energy source. Babiker et al. [20] performed a thermogravimetric analysis of date palm stones (DPS) of six cultivars and they revealed that DPS contain much volatile compounds. El May et al. [41] measured the gaseous and particulate matter obtained during the combustion of four parts of date palm wastes and their energy recovery and they found that DPS was the most convenient date palm waste for energy recovery. The objective of this study is to investigate energy production from different parts of the date palm employing proximate analyses so that such an underutilized waste might be converted into a value-added product.

2. Materials and Methods

2.1. Preparation of Date Palm Samples

Five defect-free Sukkari cultivar date palms (Phoenix dactylifera L.) with ages ranging from 10- to 15-years, were used for the experiments [7]. All palms were harvested at the Experimental Station for Research and Agriculture of King Saud University, approximately 50 km from Deyrab (Riyadh, Saudi Arabia). The site has the following characteristics: 24°6′ N latitude, 46°5′ E longitude, temperatures ranging between 10 °C in winter and 41 °C in summer, 50 mm annual rainfall and a calcareous soil.
During the seasonal pruning of date palm trees in December 2013, different date palm parts including trunk (PT), palm frond base (PFB), palm frond midrib (PFM), palm leaflets (PL), palm coir (PC), spadix stem or fruit stalk (FS), seeds or date palm stone (DPS), and fruit empty bunches (FEBs) were collected from each palm tree and weighed as displayed in Table 1. Acacia tortilis wood was used as a control sample. After air-drying, the residues were cut into small particles and ground using a Wiley mill, before the raw material was screened. Particles with a size of 20–40 mesh were used to determine the fuel characteristics, while those with a 40–60 mesh size were used for determination of the chemical and ultimate analysis of the specimens.

2.2. Chemical Analysis

Total extractives of the eight different parts of date palm were determined using a Soxhlet apparatus according to ASTM D1037 [43]. The contents of cellulose, hemicelluloses, and lignin were determined using the meal free-extractive method based on the oven-dry weights for each residue, also according to the methods described in the ASTM D1037 standard method [43]. Ash contents of the samples were calculated as a percentage of the original quantity of the specimens based on oven-dry weight according to a standard method developed by National Renewable Energy Laboratory (NREL, Golden, CO, USA) [44].

2.3. Ultimate and Proximate Analyses

Ultimate analysis of the residues of the different parts of date palm (including carbon, hydrogen and nitrogen contents) was carried out using a CHN Elemental Analyzer (model 2400 Series II Perkin Elmer, Waltham, MA, USA) at 925 °C [45]. The oxygen content of the samples was calculated by difference. For proximate analysis, residues samples were oven-dried to a constant weight at a temperature of 103 ± 5 °C. Samples having 40–60 mesh particle size were used to determine the moisture content (MC), volatile matter content (VMC) and ash content, while the fixed carbon content (FCC) was calculated by difference [43].

2.4. Fuel Characteristics of the Samples

Fuel characteristics of the specimens including heating value (HV) based on dry basis (db) and dry ash-free fuel (daf) as well as fuel value index (FVI) was determined. HV of the residues of the eight parts of the Sukkari cultivar date palms were determined on a db according to the standard method described in ASTM D2015-85 [46]. Approximately one gram of oven-dried ground sample with a particle size ranging from 20 to 40 mesh was converted into pellets using a hydraulic pellet press and loaded into a model 6300 oxygen bomb calorimeter (Parr, Moline, IL, USA). Before the analysis of the samples, the calorimeter was calibrated using benzoic acid as a standard. No correction for acid formation was included in the heating value calculations. Six samples from each date palm part were combusted to estimate the heating value. The fuel value index, FVI, was calculated using a modified method of Bhatt and Todaria [47], FVI = HV × density/ash content. Dry ash-free fuel (daf) was also calculated.

2.5. Ranking of the Different Samples

To rate the eight date palm residues of Sukkari date palm cultivar, as well as the wood of Acacia tortilis, according to the positive and/or negative impacts on the bioenergy content and environmental impact, this property was assigned a value between 1 and 9, with 1 being the best and 9 being the worst according to Munalula and Meincken [48]. Ratings were calculated as the sum of all values in the column divided by the number of measured properties (Σ/8). This rating value refers to energy output and environmental impact.

2.6. Statistical Analysis

The analysis of variance (ANOVA) using a complete randomized design (CRD) was employed to test the differences between the eight date palm residues and A. tortilis in all the measured properties using the SAS statistical package [49]. Least significant difference at 5% level of probability (LSD0.05) was used to detect the differences among the means of all the measured properties. Correlation analysis was also carried out to find out the relationship between the heating value and each of the chemical constituents and ultimate and proximate analysis of the date palm residues.

3. Results and Discussion

3.1. Chemical Composition of the Date Palm Residues

Table 2 presents the chemical composition of the eight parts of the Sukkari date palm residues compared to that of Acacia tortilis wood and other biomasses. Statistically, all of the chemical constituents showed significant differences from each other among the eight date palm residues. It can be clearly seen that the date palm residues presented a higher total extractives content (TEC) than common wood species, with a high variation range. The palm coir (PC) had the lowest TEC (7.8%) followed by date fruit stalks (FS, 9.8%), while palm leaflet (PL) had the highest amount of extractives (32.9%) followed by date palm stones (DPS) with about 31.5%. The higher extractives content of PL may be attributed to its open anatomical structure, which is accessible to the chemicals. These values are close to the values obtained on midribs of five date palm cultivars [7], and on some lignocellulosic residues [36], while they are lower than those reported for date palm trunk (PT) and rachis [11]. There is very little information to compare chemistry of the different parts of date palm residues, but the results found in this work are in partial agreement with previously published studies on non-identified date palm cultivars [17,50].
The cellulose content of the samples ranged from 32.8% for DPS to 47.5% for PC. It can be seen that PT, PFB, FS and DPS had lower cellulose content than typical wood species, while the other parts fall in the range of these wood species. These results are in accordance with the findings of a previous work carried out by Amirou et al. [11] on two date palm residues (trunk and rachis) and [7] on the midrib of five date palm cultivars. However, these values are lower than those reported for some lignocellulosic residues [36].
Except for PC and PL, the hemicelluloses content for the date palm residues were similar to those of wood and non-wood plants. The lowest values of hemicelluloses were recorded with PC and PL (12.6% and 16.1%, respectively), while the highest values were obtained with PT, PFB and DPS (Table 2). These results agree with previously reported data [7,11,13,15,16,50].
The lignin content of the samples ranged from 25.6% for PFB to 39.9% for PC. It is clear that the determined lignin contents of the DPS, PC and PL were very high when compared to that of either softwoods or hardwoods (Table 2). Other parts gave lignin values ranging from 26% to 31%, similar to those found in other wood species and non-wood plants.
Accordingly, the chemical composition of the eight date palm residues is significantly different, which may explain the differences in the fuel characteristics between them. Although no results are available in the literature for comparison with our data in this study, these results are in partial agreement with the findings of previous works [7,11,15,16,36,43].

3.2. Ultimate and Proximate Analysis of Date Palm Residues

The average proximate analysis values for the eight date palm residues are presented in Table 3. It can be seen that there is a large variation in the values of the proximate analysis results of the eight date palm residues. They had the following values: volatile matter content (VMC) ranged from 74.3% for PL to 87.5% for FBE; fixed carbon content (FCC) ranged from 10.5% for PL to 17.6% for palm trunk (PT) and the ash content ranged from 1.4% (DPS) to 15.2% (PL).
With the exception of PT, PL and FB, the VMC of the residues was greater than 82%. Most of this matter was released and burned as gases when heated during combustion process [52]. The lowest value of FCC was obtained for PL and PC without any significant differences between them and their values were less than those of A. tortilis wood (11.4%), while the remaining FCC values were higher than those of wood. The higher VMC of some date palm residues compared to the wood of A. tortilis indicated that they are more reactive than wood. The low FCC obtained in some residues reflected their high VMC, and showed that the bulk of the residues are consumed in the gaseous state during combustion.
In general, ash content is an unfavorable factor that needs to be controlled during the direct combustion of wood [53]. The date palm residues were characterized by higher ash content [7,50] than those observed in common wood species which does not normally exceed 1% but can reach up to 5% in some tropical species [54], where FB and PL had the highest ash values of 9.8% and 15.2%, respectively, which is less desirable for energy production. The high ash content in PL may be due to the concentration of potassium in the actively metabolizing positions where the nutrients from the soil are fixed prior to relocation to other parts of the plant [27]. Furthermore, tropical wood species need more mineral elements for growth than other woods [53], so the high ash content in date palm residues might be attributed to the growth conditions in Saudi Arabia where the trees grow naturally in an arid region compared to the same species growing in moist regions outside the kingdom [28].
This result is in agreement with Nasser [7], who reported that all parts of the date palm midribs had high ash content, especially the PFB, which makes them less desirable for fuelwood production. Based on the FAO [60], most of the date palm residues studied here meets the standard specifications for high-quality lump charcoal which typically has an ash content of about 3%.
By comparing the obtained values of date palm residues with coal, it can be concluded that the VMC in the residues is much higher than in coals, but FCC is much lower, which resulted in an increase in the reactivity of the residues. These results are in agreement with the outcomes of several studies worldwide that reported data for many types of biomass [36,37,38,39,41,57]. They reported the following values for general biomass including wood biomass, VMC ranged from 68% to 88%, FCC is from 7% to 35% and ash content is from 0.1% to 21% (Table 3).

3.3. Thermal Properties of the Date Palm Residues

Thermo-gravimetric analysis (TGA) shows the thermal behavior of a sample, which is an important parameter in the design of reactors for the pyrolysis of materials [61]. The TGA and derivative thermogravimetric (DTG) curves of the date palm residues are shown in Figure 1a,b. It can be said that except for PL, the thermal decomposition was complete below 500 °C. For each residue, there are one or two distinct peaks corresponding to the decomposition of hemicellulose and cellulose [62]. The decomposition of lignin took place over a wide range of temperatures up to 900 °C. The DTG curves revealed that the maximum weight loss rate was took place from 228 °C to 512 °C depending on the residue. In this temperature range, the hemicelluloses and cellulose were decomposed. The hemicellulose, cellulose and lignin decomposed in temperature ranges of 260–340 °C, 320–380 °C and 300–580 °C, respectively. During the decomposition of the three components, they are seen to be overlapped with each other and can therefore be considered as pseudo-components.
The maximum peak temperature (Tmax) ranged from 350 °C (DPS) to 467 °C (PL) and the VMC varied from 75.6% to 86.2% for PFB and A. tortilis, respectively (Table 4). It is known that the lower the Tmax of the residue, the easier it is to ignite a fuel [63]. Accordingly, it can be said that all the date palm residues are easier to ignite as fuels compared to A. tortilis, except PL and PC. This may be attributed to the higher content of lignin of PL and PC compared to the other materials. The ignition temperature (Ti), the temperature at which a sudden fall is seen in the TGA curve, was less than 300 °C and ranged from 228 °C (PFB) to 292 °C (PC). As the VMC increases, the ignition temperature falls and char becomes more reactive [63]. It is clear from Table 4 that the increase in the weight loss increases the volatile matter obtained from the TGA curve. The maximum weight loss, which occurred in the active pyrolysis zone, was ranged from about 46% for PFB to 66% for PC while the VMC ranged from about 76% to 86% for the same residues. It was reported that thermal decomposition of hemicelluloses occurs at temperatures ranging from 150 to 350 °C, while cellulose decomposes in the range of 275 to 350 °C [61]. However, lignin gradually decomposes at temperatures between 250 and 500 °C. Extractives and inorganic materials decompose at 187.9 °C.

3.4. Fuel Characteristics of the Date Palm Residues

Statistically, the differences among the eight date palm residues in terms of heating value (HV) were highly significant. The fuel characteristics for the eight date palm cultivars as well as the wood of A. tortilis are presented in Table 5. In addition, a good relationship between HV and lignin content, carbon content and ignition temperature of date palm residues (Figure 2) occurred. The HVs of the residues varied from 15.5 MJ·kg−1 for PFB to 19.9 MJ·kg−1 for PC. However, the HV on the basis of ash-free dry weight (daf) had a wide range from 16.5 MJ·kg−1 for PFB to 22.6 MJ·kg−1 for PL due to the large variation in the ash content of the residues (1.3%–11.6%) as shown in Table 5. Comparing to the heating value of the wood of A. tortilis, it can be seen from Table 5 that except for PC and DPS, all the date palm residues gave lower values than A. tortilis. The energetic density of the residues, the potential energy available per unit of biomass ranged from 3.7 (PFB) to 13.3 GJ·m−3 (DPS). In addition, the data indicated that except for DS, all date palm residues were lower than the value obtained for the wood of A. tortilis (13.6 GJ·m−3). The energetic density of the DPS and PC were close to the wood pellets (12 GJ·m−3) and they are much higher than the remained remaining date palm residues. This result is in accordance with the finding of El May et al. [41] who found that the energetic density of four date palm residues ranged from 2.6 to 11.4 GJ·m−3.
The HVs of the eight date palm residues were found to be in the range of some well-known biomass fuels reported in the literature, i.e., common reed (18.9 MJ/kg) [4], Calotropis procera (19.5 MJ/kg) [64], vine prunings (18.7 to 19.2 MJ/kg) [6], corncobs (17 MJ/kg) [1], and tobacco stems (17.8 MJ/kg) [2]. The heating values of bio-char produced from FEB ranged from 23 to 26 MJ·kg−1 [65]. In view of the obtained HVs and compared to other biomass fuels, the results indicated that these residues can be considered as a good source for energy production. Unfortunately, the high ash contents of all parts of the date palm, especially the PFB and PL, make them less desirable for use as a fuel source of because of the negative effect of ash on the fuel characteristics [57,66].
Generally, the results in Table 5 indicate that except for DPS, all date palm residues exhibited the lowest FVI values (53 to 892) compared with the values published in the literature for different wood species and general biomass, which might be attributed to the higher ash contents found in the date palm residues and the lower specific gravity. These results were in parallel with the findings of Nasser et al. [6] on vine prunings (FVI ranging from 225 to 508). On the other hand, a wide range of FVI values, from 369 for Litsea polyantha to 2089 for A. nilotica, which presented ash contents ranging from 3.6% to 0.9%, respectively, has been found [29]. This means that the ash content is the most important variable adversely affecting FVI values [6]. The FVI value of DPS is higher (2078) either than the value obtained for A. tortilis (1170) or than other date palm residues in the current study, which may be due to the higher bulk density and heating value as well as to low its low ash content.
The results indicated that among the eight date palm residues, the PFB and PL showed the lowest values for fuel characteristics, including HV, ash content and FVI, making it less desirable for use as fuelwood. On the other hand, DPS seems to be the most attractive of the date palm residues in this study for energy production and low cost transportation. This result is matched with the finding of El May et al. [41] on four date palm residues including PL, PT, PFM and DPS.

3.5. Ranking of Date Palm Residues

According to the data presented in Table 6 and using the most important measured data of the eight date palm residues in the present study, the results for a hypothetical rating are presented in Table 6. In this method, the date palm stones (DPS) showed the best value (1.9) followed by the palm coir, PC, (2.5) and A. tortilis (3.0), while the palm frond base (PFB) showed the poorest rating (6.3). The overall rating suggests that the DPS and PC show parameters suggesting they could be more suitable for energy production in Saudi Arabia compared to A. tortilis and the other date palm residues. It can be concluded that the suitability of the eight date palm residues studied here can be ranked in the following order: date palm stone > palm coir > fruit empty bunch > fruit stalk > palm leaflets > palm frond midrib > palm trunk > palm frond base. This order was established, in general, from the point of view of energy production. Unfortunately, the frond base and palm trunk are less desirable for energy production.

4. Conclusions

The present study investigated the suitability of different parts of date palm tree for charcoal production. It can be concluded that there are a large variations among the eight parts of the Sukkari date palm cultivar. It can be clearly seen that the date palm residues presented higher total extractives (8%–33%) and ash content (1%–15%) than either common wood species or other lignocellulosic materials. In these regard, date palm residues were found to have a medium to high content of cellulose (33%–48%) and lignin (26%–40%) and low to medium hemicelluloses content (13%–31%).
Large variations were found in proximate analysis values of the eight date palm residues. Volatile matter content ranged from 74.3% for PL to 87.5% for FEB; fixed carbon content ranged from 10.5% for PL to 17.6% for PT and the ash content ranged from 1.4% (DPS) to 15.2% (PL). It can be said that except for PL, the thermal decomposition was completed below 500 °C. The HVs of the residues varied from 15.47 MJ·kg−1 for PFB to 19.93 MJ·kg−1 for PC. However, the HV based on ash-free dry weight (daf) had a wide range from 16.5 MJ·kg−1 for PFB to 22.6 MJ·kg−1 for PL due to the large variation in the ash content of the residues (1.3%–11.6%). The FVI value of DPS was higher (2078) than the value obtained for A. tortilis (1170) or other date palm residues in the current study. From all the parameters studied, it would be expected that the eight parts have variations in their fuel properties and thermal behavior, where the chemical composition of these residues explain these variation. The overall ratings suggest that DPS and PC show interesting parameters, and they could be considered more suitable for energy production.

Acknowledgments

The authors would like to extend their sincerest appreciation to the Deanship of Scientific Research at King Saud University for the funding of this research through the Research Group Project # RGP-VPP-226.

Author Contributions

R.A.N. designed the experiments, wrote parts of manuscript and laboratory analyses, M.Z.M.S. wrote part of the manuscript and interpretation of the results, S.H. revised and amended the article for technical merits; H.A.A.-M., A.S.M., and M.A. analyzed some parts the data; I.M.A. contributed reagents/materials/analysis tools.

Conflicts of Interest

The authors declare no conflict of interest.

Nomenclature

ANOVAAnalysis of variance
CRDComplete Randomized Design
dafDry ash-free fuel
dbDry Basis
DPSDate Palm Stones
DTGDerivative Thermo-gravimetric
FCCFixed Carbon Content
FEBFruit Empty Bunch
FSFruit Stalk
FVIFuel Value Index
HVHeating value
LCMLignocellulosic materials
LCRLignocellulosic Residues
MCMoisture content
NRELNational Renewable Energy Laboratory
PCPalm Coir
PFBPalm Frond Base
PFMPalm Frond Midrib
PLPalm Leaflets
PTPalm Trunk
TECTotal Extractives Content
TGAThermo-gravimetric Analysis
TmaxMaximum Peak Temperature
VMCVolatile Matter Content

References

  1. Demirbas, A. Relationships between lignin contents and fixed carbon contents of biomass samples. Energy Convers. Mang. 2003, 44, 1481–1486. [Google Scholar] [CrossRef]
  2. Pesevski, M.D.; Lliev, B.M.; Zivkovic, D.L.; Popovska, V.T.; Srbinoska, M.A.; Filiposki, B.K. Possibilities for utilization of tobacco stems for production of energetic briquettes. J. Agric. Sci. 2010, 55, 45–54. [Google Scholar] [CrossRef]
  3. Salleh, F.; Samsuddin, R.; Husin, M. Bio-fuel source from combination feed of sewage and rice waste. In 2011 Internation Conference on Environment Science Engineering IPCBEE; IACSIT Press: Singapore, 2011; Volume 8, pp. 68–72. [Google Scholar]
  4. Komulainen, M.P.; Simi, E.; Hagelberg, I.; Ikonen, S.; Lyytinen, S. Possibilities of Using the Common Reed for Energy Generation in Southern Finland; Turku University of Applied Sciences: Turku, Finland, 2008; p. 21. [Google Scholar]
  5. Kitzler, H.; Pfeifer, C.; Hofbauer, H. Combustion of reeds in a 3 MW district heating plant. Int. J. Environ. Sci. Dev. 2012, 3, 407–411. [Google Scholar] [CrossRef]
  6. Nasser, R.A.; Salem, M.Z.M.; Al-Mefarrej, H.A.; Abdel-Aal, M.A.; Soliman, S.S. Fuel characteristics of vine prunings (Vitis vinifera L.) as a potential source for energy production. BioResource 2014, 9, 482–496. [Google Scholar] [CrossRef]
  7. Nasser, R.A. An evaluation of the use of midribs from common date palm cultivars grown in Saudi Arabia for energy production. BioResource 2014, 9, 4343–4357. [Google Scholar] [CrossRef]
  8. Lombard, P.; Tengberg, M. Environnement et économie végétale à Qal’at al-Bahreïn aux périodes Dilmoun et Tylos; Premiers éléments d'archéobotanique. Paléorient 2001, 27, 167–181. [Google Scholar] [CrossRef]
  9. El-Mously, H.I. The rediscovery of local raw materials: New opportunities for developing countries. Ind. Environ. 1997, 20, 17–20. [Google Scholar]
  10. Hegazy, S.S.; Aref, I.M. Suitability of some fast-growing trees and date palm fronds for particleboard production. For. Prod. J. 2010, 60, 599–604. [Google Scholar] [CrossRef]
  11. Amirou, S.; Zerizer, A.; Pizzi, A.; Haddadou, I.; Zhou, X. Particleboards production from date palm biomass. Eur. J. Wood Prod. 2013, 71, 717–723. [Google Scholar] [CrossRef]
  12. Hegazy, S.S.; Ahmed, K. Effect of date palm cultivar, particle size, panel density and hot water extraction on particleboards manufactured from date palm fronds. Agriculture 2015, 5, 267–285. [Google Scholar] [CrossRef]
  13. Khiari, R.; Mauret, E.; Belgacem, M.N.; Mhemmi, F. Tunisian date palm rachis used as an alternative source of fibres for papermaking applications. BioResource 2011, 6, 265–281. [Google Scholar]
  14. Nasser, R.A.; Hiziroglu, H.; Abdel-Aal, M.A.; Al-Mefarrej, H.A.; Shetta, N.D.; Aref, I.M. Measurement of some properties of pulp and paper made from date palm midribs and wheat straw by soda-AQ pulping process. Measurement 2015, 62, 179–186. [Google Scholar] [CrossRef]
  15. Khristova, P.; Kordsachia, O.; Khider, T. Alkaline pulping with additives of date palm rachis and leaves from Sudan. Bioresour. Technol. 2005, 96, 79–85. [Google Scholar] [CrossRef] [PubMed]
  16. Nasser, R.A.; Al-Mefarrej, H.A. Midribs of date palm as a raw material for wood-cement composite industry in Saudi Arabia. World Appl. Sci. J. 2011, 15, 1651–1658. [Google Scholar]
  17. Aref, I.M.; Nasser, R.A.; Ali, I.; Al-Mefarrej, H.A.; Al-Zahrany, S.M. Effects of aqueous extraction on the performance and properties of polypropylene/wood composites from date palm midribs and Acacia tortilis wood. J. Reinf. Plast. Compos. 2013, 32, 476–489. [Google Scholar] [CrossRef]
  18. Abu-Sharkh, B.F.; Hamid, H. Degradation study of date palm fibre/polypropylene composites in natural and artificial weathering: Mechanical and thermal analysis. Polym. Degrad. Stab. 2004, 85, 967–973. [Google Scholar] [CrossRef]
  19. Hegazy, S.; Ahmed, K.; Hiziroglu, S. Oriented strand board production from water-treated date palm fronds. Bioresource 2015, 10, 448–456. [Google Scholar] [CrossRef]
  20. Babiker, M.E.; Aziz, A.R.; Heilkal, M.; Yusup, S.; Abakar, M. Pyrolysis characteristics of Phoenix dactylifera date palm seeds using thermogravimetric analysis (TGA). Int. J. Environ. Sci. Dev. 2013, 4, 521–524. [Google Scholar] [CrossRef]
  21. Eissa, A.H.A. Quality characteristics for agricultural residues to produce briquettes. In Proceedings of the International Conference on Agricultural, Biotechnology, Biological and Biosystems Engineering, New York, NY, USA, 5–6 June 2013.
  22. Usman, A.R.; Abduljabbar, A.; Vithanag, M.; Ok, Y.S.; Ahmad, M.; Ahmad, M.; Elfaki, J.; Abdulazeem, S.S.; Al-Wabel, M.I. Biochar production from date palm waste: Charring temperature induced changes in composition and surface chemistry. J. Anal. Appl. Pyrolysis 2016, 115, 392–400. [Google Scholar] [CrossRef]
  23. Alhamed, Y. Activated carbon from date’s stones by ZnCl2 activation. JKAU Eng. Sci. 2006, 17, 75–100. [Google Scholar] [CrossRef]
  24. Al-Fuhaid, K.M. The Famous Date Varieties in the Kingdom of Saudi Arabia, 1st ed.; Ministry of Agriculture, Public Relation and Agriculture Information, FAO: Riyadh, Saudi Arabia, 2006; p. 245. [Google Scholar]
  25. Soliman, S.S.; Harhash, M.M. Effects of stands thinning on yield and fruit quality of Succary date palm. Afr. J. Biotechnol. 2012, 11, 2672–2676. [Google Scholar] [CrossRef]
  26. Agoudjil, B.; Benchabane, A.; Boudenne, A.; Ibos, L.; Fois, M. Renewable materials to reduce building heat loss: Characterization of date palm wood. Energy Build. 2010, 43, 491–497. [Google Scholar] [CrossRef]
  27. Senelwa, K.; Sims, R.E.H. Fuel characteristics of short rotation forest biomass. Biomass Bioenergy 1999, 17, 127–140. [Google Scholar] [CrossRef]
  28. Nasser, R.A.; Aref, I.M. Fuelwood characteristics of six Acacia species growing wild in the Southwest of Saudi Arabia as affected by geographical location. BioResource 2014, 9, 1212–1224. [Google Scholar] [CrossRef]
  29. Kataki, R.; Konwer, D. Fuelwood characteristics of indigenous tree species of north-east India. Biomass Bioenergy 2002, 22, 433–437. [Google Scholar] [CrossRef]
  30. Wang, S.; Huffman, J.; Littell, R. Characterization of Melaleuca biomass as a fuel for direct combustion. Wood Sci. 1981, 13, 216–219. [Google Scholar]
  31. Fengel, D.; Wengener, G. Wood Chemistry, Ultrastructure, Reactions; De Gruyter: Berlin, Germany, 1993. [Google Scholar]
  32. Nasser, R.A. Physical and mechanical properties of three-layer particleboard manufactured from the tree pruning of seven wood species. World Appl. Sci. J. 2012, 19, 741–753. [Google Scholar]
  33. McKendry, P. Energy production from biomass (part 1): Overview of biomass. Bioresour. Technol. 2002, 83, 37–46. [Google Scholar] [CrossRef]
  34. Cordero, T.; Marquez, F.; Rodriguez-Mirasol, J.; Rodriguez, J.J. Predicting heating values of lignocellulosics and carbonaceous materials from proximate analysis. Fuel 2001, 80, 1567–1571. [Google Scholar] [CrossRef]
  35. Jenkins, B.M.; Baxter, L.L.; Miles, T.R., Jr.; Miles, T.R. Combustion properties of biomass. Fuel Process. Technol. 1998, 54, 17–46. [Google Scholar] [CrossRef]
  36. Jiménez, L.; González, F. Study of the physical and chemical properties of lignocellulosic residues with a view to the production of fuels. Fuel 1991, 70, 947–950. [Google Scholar] [CrossRef]
  37. García, R.; Pizarro, C.; Lavín, A.G.; Bueno, J.L. Characterization of Spanish biomass wastes for energy use. Bioresour. Technol. 2012, 103, 249–258. [Google Scholar] [CrossRef] [PubMed]
  38. Telmo, C.; Lousada, J.; Moreira, N. Proximate analysis, backwards stepwise regression between gross calorific value, ultimate and chemical analysis of wood. Bioresour. Technol. 2010, 101, 3808–3815. [Google Scholar] [CrossRef] [PubMed]
  39. Yang, Y.B.; Ryu, C.; Khor, A.; Yates, N.E.; Sharifi, V.N.; Swithenbank, J. Effect of fuel properties on biomass combustion. Part II. Modelling approach—Identification of the controlling factors. Fuel 2005, 84, 2116–2130. [Google Scholar] [CrossRef]
  40. El-Juhany, L.I. Surveying of Lignocellulosic Agricultural Residues in Some Major Cities of Saudi Arabia; Research Bulletin No. 1-Agricultural Research Center, College of Agriculture, King Saud University: Riyadh, Saudi Arabia, 2001. [Google Scholar]
  41. El May, Y.; Dorge, S.; Jeguirium, M.; Trouve, G.; Said, R. Measurements of gaseous and particulate pollutants during combustion of date palm wastes for energy recovery. Aerosol Air Qual. Res. 2012, 12, 814–825. [Google Scholar] [CrossRef]
  42. Abed, I.; Paraschiv, M.; Loubar, K.; Zagrouba, F.; Tazerout, M. Thermogravimetric investigation and thermal conversion kinetics of typical North African and Middle Eastern lignocellulosic wastes. Bioresource 2012, 7, 1200–1220. [Google Scholar]
  43. ASTM D 1037. Standard Methods of Evaluating the Properties of Wood-Base Fiber and Particle Panel Materials; ASTM: Philadelphia, PA, USA, 1989. [Google Scholar]
  44. Sluiter, A.; Hames, B.; Ruiz, R.; Scarlata, C.; Sluiter, J.; Templeton, D. Determination of Ash in Biomass. National Renewable Energy Laboratories (NREL) Technical Report. NREL/TP-510-42622 (Internet). Available online: http://www.nrel.gov/docs/gen/fy08/42622.pdf (accessed on 5 January 2014).
  45. ASTM D 3176-89. Standard Practice for Ultimate Analysis of Coal and Coke; ASTM: Philadelphia, PA, USA, 1989. [Google Scholar]
  46. ASTM D 2015-85. Standard Test Method for Gross Heating Value of Coal and Coke by Adiabatic Bomb Calorimeter; ASTM: Philadelphia, PA, USA, 1987. [Google Scholar]
  47. Bhatt, B.P.; Todaria, N.P. Fuelwood characteristics of some Indian mountain species. For. Ecol. Manag. 1992, 47, 363–366. [Google Scholar] [CrossRef]
  48. Munalula, F.; Meincken, M. An evaluation of South African fuelwood with regards to calorific value and environmental impact. Biomass Bioenergy 2009, 33, 415–420. [Google Scholar] [CrossRef]
  49. SAS. SAS Guide to Applications Development, 2nd ed.; SAS Institute: Cary, SC, USA, 2004. [Google Scholar]
  50. Hindi, S.S.; Bakhashwin, A.A.; El-Feel, A. Physico-chemical characterization of some Saudi lignocellulosic natural resources and their suitability for fiber production. JKAU Met. Environ. Arid Land Agric. Sci. 2010, 21, 45–55. [Google Scholar]
  51. Pereira, B.L.C.; de Carneiro, A.C.O.; Carvalho, A.M.M.L.; Colodette, J.L.; Oliveira, A.C.; Fontes, M.P.F. Influence of chemical composition of eucalyptus wood on gravimetric yield and charcoal properties. Bioresource 2013, 8, 4574–4592. [Google Scholar] [CrossRef]
  52. Akowuah, J.O.; Kemausuor, F.; Mitchual, S.J. Physico-chemical characteristics and market potential of sawdust charcoal briquette. Int. J. Energy Environ. Eng. 2012, 3, 20–25. [Google Scholar] [CrossRef]
  53. Chow, P.; Lucas, E.B. Fuel characteristics of selected four year old trees in Nigeria. Wood Fiber Sc. 1988, 20, 427–431. [Google Scholar]
  54. Haygreen, J.C.; Bowyer, J.I. Forest Products and Wood Science, 3rd ed.; Iowa State University Press: Iowa, IA, USA, 1996. [Google Scholar]
  55. Arola, R.A. Wood fuels—How do they stack up? In Energy and the Wood Products Industry. Proceedings P-76-14; Forest Products Research Society: Madison, WI, USA, 1976; pp. 34–45. [Google Scholar]
  56. Gómez, N.; Rosasa, J.G.; Cara, J.; Martínez, O.; Alburquerque, J.A.; Sánchez, M.E. Slow pyrolysis of relevant biomasses in the Mediterranean basin. Part 1. Effect of temperature on process performance on a pilot scale. J. Cleaner Prod. 2016, 120, 181–190. [Google Scholar] [CrossRef]
  57. Oduor, N.M.; Githiomi, J.K. Fuel-wood energy properties of Prosopis juliflora and Prosopis pallida grown in Baringo District, Kenya. Afr. J. Agric. Res. 2012, 8, 2476–2481. [Google Scholar]
  58. Yao, H.M.; Vuthaluru, H.B.; Tadé, M.O.; Djukanovic, D. Artificial neural network-based prediction of hydrogen content of coal in power station boilers. Fuel 2005, 84, 1535–1542. [Google Scholar] [CrossRef]
  59. Lee, Y.; Park, J.; Ryu, C.; Gang, K.S.; Yang, W.; Park, Y.-K.; Jung, J.; Hyun, S. Comparison of biochar properties from biomass residues produced by slow pyrolysis at 500°C. Bioresour. Technol. 2013, 148, 196–201. [Google Scholar] [CrossRef] [PubMed]
  60. FAO. Industrial Charcoal Making; FAO Forestry Paper No. 63; Food and Agriculture Organization of the United Nations: Rome, Italy, 1985. [Google Scholar]
  61. Okoroigwe, E.C.; Saffron, C.M. Determination of bio-energy potential of palm kernel shell by physicochemical characterization. Niger. J. Technol. 2012, 31, 329–335. [Google Scholar]
  62. Yang, H.P.; Yan, R.; Chin, T.; Liang, D.; Chen, P.; Zheng, C. Thermogravimetric analysis—Fourier transform infrared analysis of palm oil wastes pyrolysis. Energy Fuel 2004, 18, 1814–1821. [Google Scholar] [CrossRef]
  63. Lopez, J.P.; Mutje, P.; Carvalho, A.J.F.; Curvelo, A.A.; Girones, J. Newspaper fiber-reinforced thermoplastic starch biocomposites obtained by melt processing: Evaluation of mechanical, thermal and water sorption properties. Ind. Crop. Prod. 2013, 44, 300–305. [Google Scholar] [CrossRef]
  64. Hindi, S.S. Calotropis procera: The miracle shrub in the Arabian Peninsula. Int. J. Sci. Eng. Investig. 2013, 2, 48–57. [Google Scholar]
  65. Sukiran, M.A.; Kheang, L.S.; Bakar, N.A.; El May, C.Y. Production and characterization of bio-char from the pyrolysis of empty fruit bunches. Am. J. Appl. Sci. 2011, 8, 984–988. [Google Scholar] [CrossRef]
  66. Goel, V.L.; Behl, H.M. Fuelwood quality of promising tree species for alkaline soil sites in relation to tree age. Biomass Bioenergy 1996, 10, 57–61. [Google Scholar] [CrossRef]
Energies 09 00374 g001 1024
Figure 1. (a) TGA curves of the eight date palm residues and A. tortilis at heating rate of 10 °C/min; (b) DTG curves of the eight date palm residues and A. tortilis at heating rate of 10 °C/min. PT: palm trunk; PFB: palm frond base; PFM: palm frond midrib; PL: palm leaflets; PC: palm coir; FS: fruit stalk; DPS: date palm stone; FEB: fruit empty bunch; AT: Acacia tortilis.
Figure 1. (a) TGA curves of the eight date palm residues and A. tortilis at heating rate of 10 °C/min; (b) DTG curves of the eight date palm residues and A. tortilis at heating rate of 10 °C/min. PT: palm trunk; PFB: palm frond base; PFM: palm frond midrib; PL: palm leaflets; PC: palm coir; FS: fruit stalk; DPS: date palm stone; FEB: fruit empty bunch; AT: Acacia tortilis.
Energies 09 00374 g001
Energies 09 00374 g002 1024
Figure 2. Relationship between heating value and lignin content, carbon content and ignition temperature of date palm residues. ** Significant at 0.01 level of probability.
Figure 2. Relationship between heating value and lignin content, carbon content and ignition temperature of date palm residues. ** Significant at 0.01 level of probability.
Energies 09 00374 g002
Table
Table 1. Characterization of different part residues of the Sukkari date palm cultivar.
Table 1. Characterization of different part residues of the Sukkari date palm cultivar.
TreeTrunk DiameterPalm HeightFrond LengthFruit Weight *Oven-Dry Weight (kg/tree)
No.(cm)(m)(cm)(Kg/tree)PFBPFMPLPCDPSFSFEBTotal
163.15.88385.3125.35.6714.408.051.3318.537.190.7555.92
251.36.15380.9144.66.4815.896.651.6520.888.061.0260.63
371.17.12345.4116.56.0813.026.302.1516.056.320.9350.85
466.65.97375.0122.36.8914.898.141.8419.198.530.7660.24
568.46.75363.5132.76.0815.117.951.5120.997.451.2060.29
Mean64.16.37370.0128.36.2414.667.421.7019.137.510.93
Each value is an average of three fronds per tree. * Oven-dry weight. PFB: palm frond base; PFM: palm frond midrib; PL: palm leaflets; PC: palm coir; FS: fruit stalk; DPS: date palm stone; FEB: fruit empty bunch.
Table
Table 2. Chemical composition (%) *of the date palm residues of Sukkari cultivar.
Table 2. Chemical composition (%) *of the date palm residues of Sukkari cultivar.
FeedstockPercentage Content of
Total Extractives 1Cellulose 2Hemicelluloses 2Lignin 2
Palm Trunk (PT)25.15 B (0.40)39.37 D (0.71)30.31 A (0.69)30.32 D (1.44)
Palm Frond Base (PFB)24.90 B (0.41)43.05 C (0.21)31.34 A (1.59)25.61 E (1.42)
Palm Frond Midrib (PFM)17.45 C (1.61)45.16 B (1.32)28.16 B (1.47)26.68 E (0.69)
Palm Leaflets (PL)32.86 A (0.85)47.14 A (0.60)16.13 E (0.15)36.73 B (0.46)
Fruit Stalk (FS)9.75 E (0.49)43.05 C (1.13)27.48 B (0.14)29.47 D (1.05)
Fruit Empty Bunch (FEB)13.42 D (0.92)44.40 BC (0.90)24.30 C (0.56)31.30 C (1.32)
Date Palm Stone (DPS)31.54 A (0.50)32.77 E (0.17)30.20 A (0.50)37.03 B (0.33)
Palm Coir (PC)7.78 F (1.35)47.50 A (0.62)12.64 F (0.41)39.86 A (0.23)
Acacia tortilis (AT)13.82 D (0.16)46.92 A (0.69)21.27 D (0.77)31.81 C (0.56)
Hardwood 32–645–5015–3523–30
Softwood 32–845–5020–3225–34
Date palm Trunk and riches 41–936–4729–3817–27
Date palm residue 520.345.029.125.8
Lignocellulosic residues 612–2951–66–11–22
Six eucalyptus clones 73–546–4922–2329–31
Midrib of six date palm cultivars 818–2441–4625–3425–30
Prunings of seven vine cultivars 918–2637–4031–3527–30
* Each value is an average for 10 specimens and the values between brackets are standard deviations. In the column, bold under line value is the highest value and bold italic value is the lowest one. Means sharing the same letters within the same column are non-significantly different at the 0.05 level of probability. 1 As a percentage of the oven-dried weight. 2 As a percentage of the free-extractives oven-dried weight. 3 Fengel and Wegener [31]. 4 Amirou et al. [11]. 5 Nasser and Al-Mefarrej [16]. 6 Jiménez and González [36]. 7 Pereira et al. [51]. 8 Nasser [7]. 9 Nasser et al. [6].
Table
Table 3. Ultimate and proximate analyses of the Sukkari date palm residues.
Table 3. Ultimate and proximate analyses of the Sukkari date palm residues.
FeedstockUltimate Analysis 1Atomic Ratio 2Proximate Analysis 1
CHNO 3H/CO/CVMAshFCC 3
PT44.46 d5.75 c0.55 c49.24 c1.55 cd0.83 c78.53 g3.86 c17.61 a
PFB40.48 f5.63 c0.28 de53.61 a1.67 a0.99 a76.56 f9.81 b13.63 c
PFM45.65 c5.95 bc0.27 de48.13 c1.56 c0.79 c82.28 e3.56 c14.15 bc
PL46.50 b5.69 c0.66 b47.15 d1.50 d0.90 b74.29 h15.2 a10.51 f
FS44.47 d5.97 bc0.32 d49.24 c1.61 b0.83 c85.32 c1.80 e12.88 d
FEB45.58 c6.03 b0.26 de48.13 c1.59 bc0.79 c87.48 a1.78 ef10.75 f
DPS47.14 ab6.63 a0.90 a45.33 e1.69 a0.72 d83.33 d1.40 f14.94 b
PC47.84 a6.15 b0.23 e45.78 e1.54 cd0.72 d86.57 b2.90 d10.53 f
Acacia tortilis46.70 b6.04 b0.34 d46.92 d1.59 bc0.79 c86.67 b1.92 e11.41 e
Hardwood [55] 450.86.40.4041.801.510.6277.33.419.4
Softwood [55] 452.96.30.1039.701.430.5677.21.622.0
LCM [34] 542–505.7–6.10.1–1.041–47--75–840.1–8.114–20
Residual biomass [56] 649–51~60.1–0.642–45--78–840.6–3.716–20
LCR [36] 7------69–881–611–25
Prosopis [57] 8------77–801.1–1.311–15
Pereira et al. [51]44–475.6–6.0~0.147–511.5–1.60.7–0.9---
Telmo et al. [38]46–524.9–6.10.1–0.540–47--75–810.1–1.012–23
Yao et al. [58]38–534.5–7.00.2–2.732–45--65–850.5–207–20
El May et al. [41]40–515.6–6.40.2–0.741–46--68–741–158–18
Nasser et al. [6]46–485.5–5.70.8–1.145–47-----
Lee et al. [59]49–624.4–6.10.2–2.033–43--49–800.4–2111–25
VM is volatile matter content and FCC is fixed carbon content. Means sharing the same letters within the same column are non-significantly different at 0.05 level of probability. 1 Percentage on a dry weight basis. 2 According to Pereira et al. [51]. 3 Calculated by difference. 4 Source: C, H, N, and O from Arola [55], while H/C and O/C ratios were calculated. 5 Lignocellulosic materials. 6 Residual biomass included olive stone, almond shell, pine wood and olive-tree prunings. 7 Lignocellulosic residues. 8 Two species of Prosopis juliflora and P. pallid grown in Kenya.
Table
Table 4. Devolatilization * of the date palm residues and A. tortilis.
Table 4. Devolatilization * of the date palm residues and A. tortilis.
FeedstockIgnition Temperature (°C)Peak Temperature Tmax (°C)Weight Loss 1 (%)Residue (%)
PT23538551.620.65
PFB22837946.324.39
PFM25237951.422.01
PL27946755.722.91
FS25337959.118.18
FEB26137860.917.76
DPS28235058.621.51
PC29241266.213.77
Acacia tortilis27439858.516.53
* These data are extracted from TGA curve with heating rate 10 °C/min in nitrogen. 1 In the zone of active pyrolysis.
Table
Table 5. Fuel characteristics of the eight date palm residues.
Table 5. Fuel characteristics of the eight date palm residues.
FeedstockHeating Value (MJ/kg)Energetic Density 1 (GJ/m3)Ash Content (%)Fuel Value Index 2
On Dry Wt Basis (db)On Ash-Free Dry Wt Basis (daf)
PT18.10 D ± 0.318.80 DE7.243.86 c187
PFB15.47 F ± 0.416.51 F3.659.81 b54
PFM17.57 E ± 0.618.21 E4.373.56 c120
PL19.60 AB ± 0.222.58 A8.2015.2 a53
FS18.07 D ± 0.218.33 E10.851.80 e892
FEB18.98 C ± 0.319.38 D9.271.78 ef487
DPS19.85 A ± 0.320.10 C13.251.28 f2078
PC19.93 A ± 0.320.70 B11.882.90 d309
Acacia tortilis19.34 B ± 0.419.56 CD13.581.92 e1170
El May et al. [41] 315–19-2.6–11.41–15-
Nasser [7] 417–1818–19-3.4–8176–306
Nasser et al. [16] 518–1919–20-2.9–4225–508
Nasser and Aref [28] 618–21--1.8–31310–2350
Kataki and Konwer [29] 714–2214–22-0.8–4369–2089
Each value is an average for 10 specimens ± standard deviation. Means with the same letters in column are not significantly different at 0.05 level of probability. 1 According to Alhamed [23]. 2 According to Bhatt and Todaria [47]. 3 Four date palm residues. 4 Midribs of common five date palm cultivars grown in Saudi Arabia. 5 Prunings of seven vine cultivars cultivated in Saudi Arabia. 6 Six Acacia species grown wild in Saudi Arabia. 7 Small branches of 35 tree species grown in north-east India.
Table
Table 6. Rating of the eight date palm residues regarding some measured characteristics.
Table 6. Rating of the eight date palm residues regarding some measured characteristics.
PropertyDPSPCA. tortilisFEBFSPLPFMPTPFB
Density182324657
Lignin content214463758
Ash content154239678
Carbon content112342345
Hydrogen content123345456
Nitrogen content613235242
Oxygen content112453456
Heating value214563768
Rank1.882.503.003.254.134.254.885.136.25
Order123456789

Share and Cite

MDPI and ACS Style

Nasser, R.A.; Salem, M.Z.M.; Hiziroglu, S.; Al-Mefarrej, H.A.; Mohareb, A.S.; Alam, M.; Aref, I.M. Chemical Analysis of Different Parts of Date Palm (Phoenix dactylifera L.) Using Ultimate, Proximate and Thermo-Gravimetric Techniques for Energy Production. Energies 2016, 9, 374. https://doi.org/10.3390/en9050374

AMA Style

Nasser RA, Salem MZM, Hiziroglu S, Al-Mefarrej HA, Mohareb AS, Alam M, Aref IM. Chemical Analysis of Different Parts of Date Palm (Phoenix dactylifera L.) Using Ultimate, Proximate and Thermo-Gravimetric Techniques for Energy Production. Energies. 2016; 9(5):374. https://doi.org/10.3390/en9050374

Chicago/Turabian Style

Nasser, Ramadan A., Mohamed Z. M. Salem, Salim Hiziroglu, Hamad A. Al-Mefarrej, Ahmed S. Mohareb, Manawwer Alam, and Ibrahim M. Aref. 2016. "Chemical Analysis of Different Parts of Date Palm (Phoenix dactylifera L.) Using Ultimate, Proximate and Thermo-Gravimetric Techniques for Energy Production" Energies 9, no. 5: 374. https://doi.org/10.3390/en9050374

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop