Article - MSAE€¦ · Web viewThe oil palm tree or (Elaeis guineensis Jacq) is a very famous plant which is known as the tree of life since it has many benefits. It is believed that

Advances in Agricultural & Food Research Journal (2020) Vol.1,Issue

Development and Performance Evaluation of the Oil Palm Fruit Bunch Chopping Machine

F.S. Ali1, R. Shamsudin1*, R. Yunus2

1Department of Process and Food Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia2Department of Chemical and Environmental Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor,

Malaysia* Corresponding author. Tel.: 603-89466366; Fax:603-89466366.E-mail address of corresponding author: [email protected]

Abstract

A chopping machine was developed to chop oil palm fruit bunch prior to the sterilization process. The chopping mechanism was a new invention as an alternative to the current bunch crusher in the palm oil mill. This invention was introduced to chop the fruit bunch into small parts in order to improve the heat penetration into the inner layers of the fruits during the sterilization process. The effectiveness of the sterilization process could produce superior oil quality as well as oil recovery. The chopping machine was comprising of a conveyor, a specialized chopping blade to chop the fruit bunch, a v-shaped platform and a dropping system. Based on the findings, the machine capacity, feed rate, machine efficiency, the percentage of damaged, power consumption and cost of operation were 376.99kg/hr, 34 bunches/hr, 93.37±1.63%, 6.64±1.64%, 88.62kW/hr and RM19.32/hr respectively. The results also showed that the machine performance need to be improved in terms of machine capacity and feed rate to achieve high of productivity as comparable in the mill throughout the future research.

Keywords: Oil palm fruit bunch; chopping machine; machine performance; machine capacity; feed rate; machine efficiency; percentage of damaged fruits; power consumption; cost of operation;

1. Introduction

The oil palm tree or (Elaeis guineensis Jacq) is a very famous plant which is known as the tree of life since it has many benefits. It is believed that the origin of the oil palm is from the West and Central Africa. It has spread into 43 countries such as Africa, Indonesia, Malaysia, India, Colombia, Thailand and others. Typically, the weight of a young oil palm fresh fruit bunch (FFB) is about 5 kg-15 kg and 40 kg for a very old fruit bunch (Razali et al., 2012). The FFB consists of stalks, spikelets and oil palm fruits which compactly packed in a bunch. Depending on its size and ages, a bunch may contain at least a few hundred to more than two thousand fruits. As the fruits ripen, they are harvested and sent to the palm oil mill for oil extraction and further processing.

Milling is a crucial process to extract the crude palm oil from the fruit mesocarp. It also involves the initial detachment of the individual fruits from its bunch. The milling process starts with the bunch reception, and continues with sterilization, threshing, digestion, pressing, clarification and purification. Initially, the FFB including the loose fruits are fed into the sterilizer cages through the hopper. The purposes of the sterilizing process are to cook as well as to soften the mesocarp cells, deactivate the lipase enzyme,

2 Advances in Agricultural & Food Research Journal (2020) Vol.1,Issue 1

facilitate the detachment of fruits from the stalks and to prepare the initial separation of the kernel from its shell (Wan Ismail et al., 2011). The FFB are sterilized at a high pressure ranging between 15-45 psi for 90 minutes (Umudee et al., 2013). However, the heap of the FFB arrangement causes poor heat penetration into the inner layers of the FFB. In addition, the variation of FFB size and different level of ripeness leads to undetached fruit bunches (USB) and poor oil recovery.

Recently, the continuous sterilizer system is being operated in the mill to tackle this problem. The FFB was crushed into small parts by using the double roll crusher. The crushed FFB was conveyed into an enclosed continuous sterilizer at atmospheric pressure. However, the small opening gap of the double roll crusher cause the large FFB are crushed with great pressure and this causes severe damage while the small FFB are not being open up, effectively. Approximately 30.7% of damaged fruits was produced due to the crushing process (Kandiah et al., 2002). The damaged fruits also cause oil to exude from the mesocarp of the fruit during the steam injection (sterilization process) and consequently, the oil is washed out and collected in the condensate. Other than that, the oil is also absorbed by the empty fruit bunch (EFB). This problem led to poor crushing effectiveness as well as poor oil recovery and oil quality (Fatin et al., 2014).

Therefore, this study was attempted to approach a chopping mechanism to replace the bunch crusher prior to the sterilization process. A preliminary study was carried out to determine the mechanical properties and the effect of chopping the fruit bunch upon the oil quality using a fabricated chopping blade which was fixed on the Universal testing machine (Fatin et al., 2014). The study was proved that the chopped FFB can be stored less than 120min of storage time before being transferred into the sterilizer. The oil quality in terms of free fatty acid (FFA), moisture content, Deterioration of Bleachability Index (DOBI) and carotene content was satisfied and obeyed the PORIM standard specification for crude palm oil.

However, only a moderately few studies have been published concerning the cutting devices specifically used for oil palm fruits. Therefore, a chopping machine was developed in a small prototype as an alternative to chop the FFB into small parts. The chopping machine was comprising of a conveying part, chopping part, a v-shaped platform and a dropping part. An electric power source with three phases, sequencing controls and electronic components were used to incorporate the whole compartments. The objective of the study was to design and evaluate the machine performance in terms of machine capacity, feed of rate, machine efficiency, percentage of damaged fruits, power consumption and cost of operation.

2. Materials and methods

2.1. Machine description and operation

The oil palm fruit bunch chopping machine was developed into a small scale of a prototype to demonstrate a chopping mechanism of the FFB prior to sterilization process as shown in Fig. 1. It consists of three main components which were conveying part, chopping part and dropping part. The most important component of this machine was the chopping part whereby it consists of a cross-shaped chopping blade, a v-shaped platform and a pusher drive. The FFB was conveyed into the v-shaped platform using a conveyor belt which driven by an electric motor with specification of 1Hp and 1380rpm (Model BAB02-4, Branco, Italy). The v-shaped platform was used to hold the FFB during chopping process. It consisted of four plates and the gap opening between the plates was designed to be 25 mm to ensure the blade can pass through it during the chopping process. The angle of the platform was designed to be 45-90o to hold the fruit bunch during the operation. It was specially designed due to the shape of the fruit bunch which is almost sphere and elongated. The utmost importance of the platform design was able to hold the fruits during the operation without any additional clamping tools. In addition to that, the platform was made of stainless steel and hardened to avoid problems from corrosive fluids and excessive force during the chopping operation.

Gap

Advances in Agricultural & Food Research Journal (2020) Vol.1,Issue 1


Conveying process V-shaped platform

Chopped fruit bunch Chopping process

Fig. 1. The schematic drawing of the chopping process.

Once the FFB was dumped onto the platform, the chopping blade automatically moved down with a constant speed of 150 mm/min and cut the FFB. The dimension of the blade was 400 mm in width x 250 mm in height x 100 mm in thickness. The dimensions were chosen according to the average size of small to medium FFB. The cross-shape of the chopping blade was specially designed to provide equal force acting on the surface during the operation. It was driven by an alternate current (AC) motor (Model BA802-4, Branco, Italy) which was mounted on the top of the frame stand. The travelling of the blade upward and downward was controlled by two travel switches at the top and bottom of the plate. During the chopping process, the FFB was chopped in horizontal plane position as the cutting force required is lower compared to the vertical plane cutting method. This is due to the core or hard stalk which is elongated in the fruit bunch. Thus, chopping the FFB in horizontal plane position could reduce the penetration of the blade against thickness.

The dropping part consisted of a pusher drive, motor, and two travelling switches. After the chopping process, the chopping blade travelled upward and the pusher drive moved horizontally to push the chopped FFB. The pusher was driven by 1Hp of alternate current (AC) motor (Model Series 71M2-4, Branco, Italy). Total time taken by the machine to chop and drop the FFB was 0.029hr per cycle.

2.2. Sample Preparation

The ripe Tenera species of oil palm fruit bunches were harvested from Taman Pertanian Universiti, Universiti Putra Malaysia. For this study, the small to medium fruit size was selected from the age of 8-10 years old oil palm tree, specifically which around 8-15 kg per bunch in weight. The fruit bunch were loaded on the conveyor part and chopped into four parts.

2.3. Determination of machine capacity

Machine capacity is defined as the ability of the machine to chop the oil palm fruit bunch in a specific time. Firstly, the fruit bunch was weighed using a weighing scale (Model ICS629, Mettler, USA) and loaded onto the conveyor to undergo the chopping process. The total time was taken from the conveying process till the end of the chopping process. The machine capacity was calculated using equation 1:

(1)Machine Capacity=weightFFB(kg )

time (hr )


2.4. Feed rate of the machine

The feed rate may be defined as the rate at which the quantity of fruit bunch was fed into the machine. The equation used for this purpose was referenced from the method by Ojomo et al., 2010 with some modification. The feed rate was determined by calculating the time taken to feed the fruit bunch into the v-shaped platform. The calculation is given in equation 2.

(2)

2.5. Determination of machine efficiency

The machine efficiency was determined to measure the effectiveness of the machine to chop the fruit bunch. The chopped fruits and unchopped (or undamaged) fruits were weighed using a weighing scale (Model ICS629, Mettler, USA). The machine efficiency was calculated based on the following equation.

(3)

2.6. Percentage of damaged fruits

Initially, the fruit bunch was weighed and chopped by the chopping machine. The damaged fruits were manually collected and weighed as shown in Fig. 2. Three replications of the analysis were performed to obtain the average results. The percentage of the damaged fruits was calculated using equation 4:

Fig. 2. The damaged fruits were collected and weighed.

(4)

2.7. Power of consumption

The power consumption of the FFB chopping machine was calculated to predict the usage of electrical energy over time during the machine operation. Equation 5 was used to calculate the power consumption of the machine within one hour operation (Ojomo et al., 2010).

(5)

Damaged fruits

Feed rate=Quantity FFB

time (hr )

Machine Efficiency( % )=weightundamagedfruits(kg )

weight FFB(kg )×100%

% damaged fruits=weight damagedfruits(kg )

weight FFB (kg )

Power Consumption (kW /hr )= Power Consumed per cycle (kW )time(hr )


2.8. Cost of operation

The cost of operation was calculated using equation 6 and 7 as listed below. The Tariff was referred to the current Tariff from Tenaga Nasional Berhad.

(6)

(7)

3. Results and Discussions

3.1. Machine capacity, feed of rate and machine efficiency

Table 1 shows the results obtained from the experiment. The average weight of FFB used in this experiment was approximately 11.088±2.61kg. The standard deviation was high due to different range of the fruit size and weight which was between 8kg to 15kg. The total time taken by the machine to chop and drop the FFB was about 0.029hr per cycle. Therefore, the machine was able to chop about 376.992kg FFB/hr or approximately 0.38ton FFB/hr of chopped fruit bunches in one hour processing. While, the feed rate of the machine was 34 fruit bunches per hour. The machine capacity and feed of rate were quite low as compared to the continuous mill which could process 10ton FFB/hr. Apart of that, the machine capacity and feed rate also mostly depend on the speed of cutting, blade size and power of the electric motor.

Table 1: The summary of results (Data are Mean Values ± Standard Deviation).

Performance Evaluation Results

Machine capacity (kg/hr) 376.99

Feed rate of the machine (FFB/hr) 34 FFB

Machine efficiency (%) 93.37±1.63

Percentage of damage fruits (%) 6.64±1.64

3.2. Percentage of damaged fruits

The damaged fruit was categorized as the chopped fruits after the chopping process. By using equation 4, it was found that the percentage of damaged fruits was ranging between 6.64% compared to the bunch crusher that caused 30.74% of bruised fruits due to the crushing process (Kandiah et al., 2002). The high of standard deviation was obtained due to the variation of size and shape of the fruit bunch. Overall, the results proved that, the chopping method could reduce the damaged area of the fruits simultaneously prevent severe damaged of the fruits cell. The lower of the damaged fruits could reduce the oil losses in the oil condensate subsequently increase the oil extraction rate in the mill.

3.3. Power consumption and cost of operation

Energy Consumption (kWhr )=Power Consumption (kW )×Hour (hr )

Cost=Energy Consumption×Tariff


The cost of power consumed was also determined to predict the cost of electricity per month. As listed in Table 2, the current tariff price was referred in Tenaga Nasional Berhad website.

Table 2: Tariff rates for the domestic consumer.

Tariff A-Domestic Tariff Unit Rates (sen)

For the first 200 kWh (1- 200 kWh) per month sen/kWh 21.8

For the next 100 kWh (201- 300 kWh) per month sen/kWh 33.40



For the next kWh (901 kWh onwards) per month sen/kWh 57.10

The minimum monthly charge is RM 3.00

(Source: Tenaga Nasional Berhad, 2014)

The power consumed for the whole of the chopping process was calculated including the chopping and dropping process. Based on the Table 3, it was found that 2.57kw of the power consumed per one cycle operation. The total power consumed was 88.62kW/hr during one hour of operation. All the calculations were obtained using equation 5, 6 and 7.

Table 3: Power consumption and electricity cost of the FFB chopping machine.

Component Power consumed per cycle (kW)

Chopping 2.2

Dropping 0.37

Total Power consumption (one cycle)(kw) 2.57

Total Power consumption (kw/hr) 88.62

Electricity cost per hour (RM) 19.32

It was expected that the power and electricity cost was higher in the continuous sterilization (CS) mill since it used two crushers for each line of processing as compared to the chopping machine. Normally, in the mill, there was two stages of crushing process. The first crusher was installed before the FFB loading into the sterilizer and another one was placed at the second thresher. The function of the second crusher was to ensure the hard FFB can be crushed and fruits can be detached. By approaching this chopping machine, it can replace the crusher to chop the fruit bunch effectively.

4. Conclusion

The results show that the oil palm fruit bunch chopping machine can achieve high of efficiency to chop the fruit bunch into small parts. The percentage of the damaged fruits can be reduced as it was relied on the design of the blade when compared to the bunch crusher. In fact, reducing the damaged fruits will reduce the amount of oil losses. However, the machine capacity and the feed rate were not comparative with milling


industry since the machine was integrated with programmable logic controller (PLC) system and electrical motorized system. Therefore, further study must be conducted to improve the machine performance specifically on the machine capacity and upgrading the system to be high productive as well as less maintenance.

Acknowledgement: The researchers would like to thank the staffs of Felda Mill in Trolak, Perak for their assistance.Funding: This research was supported by Long term Research University Grant (LRGS) of Universiti Putra Malaysia, Serdang, Selangor, Malaysia.Conflicts of Interest: The authors declare no conflict of interest, and also the funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

Reference

Fatin, S.A., Rosnah S., Yunus, R., 2014. The effect of storage time of chopped oil palm fruit bunches on the palm oil quality. Journal of Agriculture and Agricultural Science Procedia. 2nd International Conference on Agricultural and Food Engineering (CAFEi2014). Vol.2, 2014,165-172.

Kandiah, S., Basiron,Y., Suki,A., Mohd Taha, R., Yu Hwa,T Mohd Sulong., 2006. Continuous sterilization: The new paradigm for modernizing palm oil milling. Journal of oil palm Research (special Issue-April 2006),144-152.

Kandiah, S., Mohd Halim., R., Basiron, Y., Abdul Rahman, Z., Ah Ngan, M., 2002. Continuous sterilization of fresh fruit bunches. MPOB TTNo.148. MPOB information series ISSN 1511-7871.

Ojomo, A. O., Ologunagba, F.O., Alagha, S.A., 2010. Performance evaluation of a palm fruit bunch stripper. Journal of Engineering and Applied Sciences. Vol.5, No.9,29-33.

Razali, H., Halim, A.S.M.A., Roslan, S., 2012. A Review of Crop Plant Production and Ripeness Forecasting. International Journal Agriculture and Crop Sciences.Vol.4, No.2, 54-63.

Sukaribin, N., Khalid, K., 2009. Effectiveness of Sterilization of Oil Palm Bunch Using Microwave Technology. Crops and Products, Vol.30, No.2,179-183.

Tenaga Nasional Berhad. Retrived on 20th January 2014 from http://www.tnb.com.my/tnb/residential/pricing-and-tariff/tariff-rates.html.

Umedee,I., Chongcheawchamnan, M., Kiatweerasakul, M., Tongurai, C., 2013. Sterilization of Oil Palm Fresh Fruit Using Microwave Technique. International Journal of Chemical Engineering and Applications, Vol.4, No.3,111-113.

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Article - MSAE€¦ · Web viewThe oil palm tree or (Elaeis guineensis Jacq) is a very famous plant which is known as the tree of life since it has many benefits. It is believed that