International Journal of Material Science Innovations Volume 03, Issue 02, Pages 60-67, 2015

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1 International Journal of Material Science Innovations Volume 03, Issue 02, Pages 60-67, 2015 ISSN Characterisation of briquettes from Rice Bran and Palm Kernel Shell Mohammed, T.I., Olugbade, T.O. * Department of Mechanical Engineering, Federal University of Technology, P.M.B 704, Akure, Ondo State, Nigeria. * Corresponding author. Tel.: address: tkolugbade@futa.edu.ng A b s t r a c t Keywords: Agricultural residues, Biomass, Briquette, Palm kernel shell, Rice bran. Accepted:20 April2015 Fuel properties are very important in the selection of briquettes for domestic and industrial cottage applications as they go a long way in determining the combustibility and ignitability of the briquettes. In this work, investigations were carried out on properties of briquettes produced from the mixture of rice bran and palm kernel shell using cassava starch as binder with a view to finding out the suitability of the briquettes for use as high grade fuel. Ultimate and proximate analyses were carried out to determine the average composition of their constituents. The residues were compressed into briquettes in the mould of an existing manually operated briquette machine having efficiency of 85 %. The results of this work indicate that briquettes produced from the mixture would make good biomass fuels. However, findings show that the briquette from the mixture has a moisture content of 18.97%, volatile matter of 64.54%, ash content of 14.16%, fixed carbon of 21.30% and density of 524 kg/m3. The ultimate analysis of the briquette resulted into %, 5.80 %, 0.05 %, 1.78 % and % for Carbon, Hydrogen, Sulphur, Nitrogen and Oxygen respectively. It also has heating value of 14.25MJ/kg and compressive strength of 1.08 kn/m 2. Academic Research Online Publisher. All rights reserved. 1. Introduction Fuel is the natural or artificial organic substance that is used as source of energy and raw material for industries [1]. All kinds of fuel are divided into solid, liquid and gaseous with regards to their state of aggregation and classified as natural and artificial fuels with respects to their origin [1]. A solid fuel to which bound or compressed rice bran (briquettes) belongs is grouped as fuel from natural origin. Briquette is a block of flammable matter used as fuel to start and maintain a fire [2]. It can be homogenous (of the same components materials) or non-homogenous (of different components materials) and the process of compacting loose combustible materials for fuel making purpose is briquetting. The products obtained from the process of briquetting are known as briquettes. Likeable materials for briquette are sawdust, paper mill waste, coconut husks, rice bran, olive refuse, wheat straw etc. Recently, several researches have been conducted to prepare the biomass briquettes. For example, [2] studied the effects of compressive force, particle size, and moisture content on the mechanical properties of biomass pellets from grasses (such as wheat straw, barley straw, etc.). The physical and thermal properties of extruded derived fuel were investigated by [3]. The factors affecting strength and durability of densified biomass products were 60 P a g e

2 reviewed by [4]. Among several kinds of biomass, agricultural residues have become one of the most promising choices. Some agricultural wastes such as wood can be directly utilized as fuels. Nevertheless, a majority of them are not suitable apparently because they are bulky, uneven, and have low energy density. All these characteristics make them difficult to handle, store, transport, and utilize in their raw form. Hence, there is the need to subject them to conversion processes in order to mitigate these problems. One of the promising solutions to these problems is the application of briquetting technology [5]. Appreciable studies have been carried out on briquetting process. Such agro-residues already studied include briquette from sawdust and palm kernel [6], briquette from olive refuse and paper mill waste [7], maize cob [5], maize cob and coal particles [8], groundnut and melon shells [9], rice husk only [10], waste paper and admixture of coconut husk [11] and banana peel [12], among others. Fuel briquettes produced under different conditions have been reported to have different handling characteristics. These characteristics are also found to be strongly affected by the raw material properties. If biomass or agro-waste briquettes are to be used efficiently and rationally as fuel, they must be characterized to determine parameters such as the moisture content, ash content, density, volatile matter, and heating value among others. The result of these determinations indicates the positive and negative attributes of the agro waste briquettes [10]. The broad objective of this work was to characterize biomass briquettes from the mixture of rice bran and palm kernel shell using cassava starch as binder. This was done by the determination of physical and combustion properties of the briquettes produced. Furthermore, the results obtained were compared with the existing work. 2. Materials and Methods Rice bran and palm kernel shell that were used in this experiment were obtained from farm waste dumps. These materials were selected because they are readily available in large quantities. The unwanted materials were removed by sorting method to ensure fine particles of the bran while the palm kernel shells were grinded into particles and cassava starch which was sourced locally was used as binder. The briquettes were formed by compressing the mixture of rice bran and palm kernel shell in the mould of an existing manually operated briquette machine having efficiency of 85 %. The briquettes produced from rice bran and palm kernel shell using starch as binder are shown in Plate P a g e

3 International Journal of Material Science Innovations Volume 03, Issue 02, Pages 60-67, 2015 ISSN Plate 1: Briquettes from Rice Bran and Palm Kernel Shell using Starch as Binder 2.1 Determination of Physical and Combustion Characteristics of the Briquettes Produced The density of briquettes from each residue was determined immediately after ejection from the mould and this was calculated from the ratio of the mass to the volume of briquette. The mass was obtained by using a digital weighing scale, while the volume was calculated by taking the linear dimensions (length, breadth and thickness) of the briquette by means of a Vernier caliper. The moisture content (MC) of the ground material before and after compaction was determined by experiment using [13] standard involving the use of oven drying methods. The initial weight of the sample was determined (W 1), and placed in an oven set at 103ºC for 24 hours. The samples was removed and cooled in a dessicator, reweighed (W 2). Moisture content of the sample was calculated from the following expression, MC = W 1 W 2 W [13] (1) The percentage volatile matter (PVM) was determined according to [14] standard method, where 2 g of pulverized briquette sample in a crucible was placed in the oven until a constant weight was obtained. The briquette was kept in the furnace at a temperature of 550 o C for 10 minutes and weighed after cooling and the percentage volatile matter was determined with the formula, PVM = Where, B C B 100 [14] (2) B is the weight of oven dried sample and C is the weight of sample after 10 min in the furnace at 550 o C. The percentage ash content (PAC) was determined using [15] standard method. 2 g each of the specimens was placed in the crucible and the weight of the crucible plus specimen was 62 P a g e

4 determined. The crucible and contents, was then placed, with cover removed, in the muffle furnace at 600 o C and ignited until all the carbon is eliminated. It was heated slowly at the start to avoid flaming and the crucible was protected from strong drafts at all times to avoid mechanical loss of test specimen. The weight was recorded (crucible plus specimen minus weight of crucible) as the weight of the oven-dry test specimen. PAC = D 100 [15] (3) B where D is the weight of ash, B is the weight of oven dried sample The percentage fixed carbon (PFC) was calculated by subtracting the sum of percentage volatile matter (PVM) and percentage ash content (PAC) from 100. PFC = 100 (PVM + PAC) (4) Furthermore, the heating value of the two biomass briquettes was also examined and the procedure in accordance with [16] was followed. The apparatus used was Gallen Kamp Ballistic Bomb Calorimeter. The compressive strength of the briquettes was determined in accordance with [17]. kernel shell briquette are shown in Tables 1 and 2, while the result of the water boiling test showing the variation of temperature with time for both the briquette and firewood is presented in Table 3. The graph of temperature versus time for both the briquette and firewood is presented in Figure 2. The proximate analysis gives the percentage volatile matter, percentage ash and percentage fixed carbon of the briquette while the ultimate analysis was performed on finely ground and oven dried samples to find the amount of Carbon, Hydrogen, Nitrogen and Sulphur (C, H, N, and S) by using the CHNS Elemental Analyzer. The experiments were performed trice and the mean readings were taken for all the characterization. The briquette from the mixture has a volatile matter of 64.54%, ash content of 14.16%, fixed carbon of 21.30% and density of 524 kg/m3. The ultimate analysis of the briquette resulted into %, 5.80 %, 0.05 %, 1.78 % and % for Carbon, Hydrogen, Sulphur, Nitrogen and Oxygen respectively. These results are presented in Table 1. The briquette from the mixture also has a moisture content of 18.97%, heating value of 14.25MJ/kg and compressive strength of 1.08 kn/m 2 as shown in Table Results and Discussion The results of the determination of physical and combustion characteristics of rice bran and palm 63 P a g e

5 Table 1: Physical and Fuel Characteristics of Briquette from Rice Bran and Palm Kernel Shell Parameters Unit Briquette Mean Replicate 1 Replicate 2 Replicate 3 Value Length of the Briquette mm External diameter of the Briquette mm Internal Diameter of the Briquette mm Weight of the Briquette kg Carbon Content % Hydrogen Content % Sulphur Content % Nitrogen Content % Oxygen Content % Volatile Matter % Ash Content % Fixed Carbon % Table 2: Combustion Characteristics of Rice Bran and Palm Kernel Shell Briquette Parameters Unit Mean value Moisture Content % Compressive Strength kn/m Heating Value MJ/kg Table 3: Briquette (Rice Bran and Palm Kernel Shell) versus firewood Rice bran and palm kernel shell Firewood (Starch as binder) Time Temperature of H 2O ( 0 C) Time Temperature of (min) Replicate 1 Replicate 2 Replicate 3 Mean Temp. (min) H 2O ( 0 C) P a g e

6 Temperature ( 0 C) % Composiition of Briquette Olugbade et al. / International Journal of Material Science Innovations (IJMSI) 3 (2): 60-67, 2015 The graph showing the percentage composition of the briquette is presented in Figure 1 while the graph of temperature versus time of boiling water. for both the produced briquette and firewood is given in Figure Fig.1: Percentage Composition of the Briquette Rice bran briquette Firewood Time (min.) Fig.2: Temperature versus time for both the briquette and firewood From the result, Table 3 shows the variation of temperature with time for both rice bran and palm 65 P a g e

7 kernel shell briquette using starch as binder and firewood (both from initial temperature of 27 0 C), it is seen from this table that the briquette attained a mean temperature of C in 3 minutes while firewood attained a temperature of 41 0 C at the same time interval. In 6 minutes, the mean temperature of the water for rice bran and palm kernel shell - starch briquette rose to C, followed by C in 9 minutes, C in 12 minutes and finally C in 15 minutes. Compared to fire wood which burns slowly from 46 0 C in 6 minutes, 53 0 C in 9 minutes, 68 0 C in 12 minutes, 82 0 C in 15 minutes, 94 0 C in 18 minutes and finally C in 21 minutes. From the result obtained it can be seen that the water heated with rice bran and palm kernel shell - starch briquette took 15 minutes to boil 2 litres of water compared to firewood that took 21 minutes to boil the same quantity of water. This difference can also be observed from the graph of temperature versus time for both the briquette - starch and firewood as shown in Figure 2. The rapid combustion observed could be due to porous nature of the rice bran briquettes compared to the relatively dense firewood. The porosity in the rice bran briquettes enables the volatiles to leave more readily and be consumed rapidly in the flame. This explains the sharp temperature rise within the first 6 minutes and the fact that cellulose materials often display flaming combustion. 4. Conclusion Fuel characterization of briquette produced from rice bran and palm kernel shell was done and the ultimate analysis for the briquette resulted into %, 5.80 %, 0.05 %, 1.78 % and % for Carbon, Hydrogen, Sulphur, Nitrogen and Oxygen respectively. Proximate analysis gave %, %, %, and % for moisture content, volatile matter, ash content and fixed carbon respectively. The values of volatile matter and ash content are good and acceptable compared to the results from the previous work. The briquette performance was evaluated compared to firewood through water boiling test which showed that 1 kg of the briquette took 15 minutes to boil 2 litres of water where as it took 1.2 kg of firewood 21 minutes to boil the same quantity of water. The results show that briquettes produced from mixture of rice bran and palm kernel shell is a good bio-fuel than one from rice bran alone. This research work will help in many ways. The disposal challenges of accumulated rice bran at mills and crop residues on the field will be resolved through briquette making and its attendant energy utilization. The current pressure on forest and forest products for rural energy supply will be minimized. Also, harnessing rice bran for energy will promote rice cultivation and guarantee national food security and heat will be generated for domestic and industrial cottage applications since a lot of potential energy abounds in these residues. References [1] Mukhylonov JP. Fundamentals of Chemical Technology. Mir Publishers, Moscow, 1996; [2] Mani S., Tabil LG and Sokhansanj S. Effects of compressive force, particle size and moisture content on mechanical properties of biomass pellets from grasses, Biomass and Bio energy 2006; [3] Marsh R., Griffiths AJ, Williams KP and Wilcox SJ. Physical and thermal properties of extruded refuse derived fuel, Fuel Processing Technology 2007; [4] Kaliyan N., Morey RV. Factor Affecting Strength and Durability of Densified Biomass 66 P a g e

8 Products, Biomass and Bio Energy 33, 2009; [5] Wilaipon P. Physical Characteristics of Maize Cob Briquettes under Moderate Die Pressure. American Journal of Applied Science. 2007;(4): [6] Adegoke CO and Mohammed T.I. The Effects of Palm Kernel Shell on Calorific Value of Sawdust Briquettes. Journal of Apply Science, 1999; 10(2): [7] Yaman S., Şahan M., Haykiri-açma H., Şeşen K. and Küçükbayrak SK. Production of Fuel Briquettes from Olive Refuse and Paper Mill Waste, Fuel Processing Technology, 2000; [8] Wilaipon P. Density Equation of Bio-Coal Briquette and Quantity of Maize Cob in Phitsanulok, Thailand. American Journal of Applied Sciences, 2008a; 5(2): [9] Oladeji JT. Fuel Characterization of Briquettes Produced from Corncob and Rice Husk Residues. The Pacific Journal of Science and Technology II, 2010; [10] Musa NA. Comparative Fuel Characterization of Rice Husk and Groundnut Shell Briquettes. NJREDl, 2007; 6(4): [11] Olorunnisola AO. Production of Fuel Briquettes from Waste paper and Coconut Husk Admixtures. Agricultural Engineering International: The CIGR E-Journal. Manuscript EE , 2007; [12] Wilaipon P. The Effects of Briquetting Pressure on Banana Peel Briquette and the Banana Waste in Northern Thailand. American Journal of Applied Sciences, 2008b; 6(1): [13] ASTM E Standard Test Method for Moisture Analysis of Particulate Wood Fuels. ASTM International: West Conshohocken, PA, [14] ASTM E Standard Test Method for Volatile Matter in the Analysis of Particulate Wood Fuels. ASTM International: West Conshohocken, PA, [15] ASTM D Standard Test Method for Ash in Wood. ASTM International: West Conshohocken, PA, [16] ASTM E Test Method for Gross Calorific Value of Refine-Derived Fuel by the Bomb Calorimeter. ASTM International: West Conshohocken, PA, [17] ASTM S D Standard Methods of Evaluating the Properties of Wood Based Fibre and Particle Board Material: ASTM: Philadelphia, PA., P a g e