Palm Oil Sector
Palm oil industry is the pillar to change Malaysia’s economy and plays a major role as the largest exporter of palm oil worldwide and the second largest producer after Indonesia. There are few types of palm oil species available globally but in Malaysia, oil is extracted from mesocarp of oil palm species called Elaeis guineensis. Palm oil has become a global interest for its renewable and sustainable raw materials. In reality, oil palm agricultural has begun in the year 1917 at a slow growth and after the last 50 years of the plantation, then the development was in rapid pace through large-scale investment on that agricultural industry. Thus, production of oil palm is increasing. In 1985, the palm tree was planted in 1.5 million hectares and in 2007, it increased to 4.3 million hectares. It has become the most important commodity crop in Malaysia. In 2011 the total hectares palm tree plantation area was 4.917 million. Over the years, palm oil production has shown an increase from 4.1 million tonnes in 1985 to 6.1 million tonnes in 1990. In 2011 and 2012 showed 18.9 million tonnes and 19.4 million tonnes respectively. http://www.palmoilworld.org/about_malaysian-industry.htmlWaste Generated from Palm Oil Sector
In Malaysia, 94% of biomass enormously produced from palm oil sector and the balance is from the agricultural and forestry sectors like wood, rice husks and sugar cane (biochar from treated and untreated). Solid oil palm biomass from the palm oil mill throughout the year consist of empty fruit bunch (EPF), mesocarp fiber (MF), palm kernel soil (PKS), oil palm trunk (OPT), oil palm frond (OPF). Each of fresh fruit bunch (FFB) containing 21 % crude palm oil (CPO), 6-7% palm kernel, 13.5-15% MF, 5.5-7% PKS and 22-23% EFB. (biochar from oil palm biomass: a review of its potential and challenges). The oil palm production in the year 2012 generated 95.21 million tonnes of oil palm waste which includes 21.90 mtonnes of EFB, 12.38 mtonnes of OPF, 5.71 mtonnes of PKS, and 55.22 mtonnes of mill effluent (POME). (Sustainable Biofuels and Other Related Bio-Products from Palm Cultivations). The average weight of palm fronds that had entered the cutting period is equal to 4 g per dry frond, with a total production of palm fronds around 5500 kg hectare per year. (characeristics of activated carbon results from pyrolysis of oil palm fronds powder). Oil palm frond biomass consists of 30.4 % dry wt. of cellulose, 40.4% of hemicellulose, 21.7% lignin, 1.7% extraction and 5.8% ash (biochar from oil palm biomass: a review of its potential and challenge).
Bio-char is known as carbonaceous material produced from biomass by pyrolysis under zero or limited supply of oxygen to capture combustible gases and usually in low temperature and heating rate. Bio-char consists of volatile matter, ash content, fixed carbon, and moisture content. The product yields are influenced by the types of feedstock, structural composition, and pyrolysis condition for example residence time, heating rate and temperature of the pyrolysis process. Slow and fast pyrolysis is usually be determined from heating rate and residence time and for production of bio-char usually used slow pyrolysis or called as conventional carbonization at long residence time but the low heating rate and for fast pyrolysis is vice versa. Bio-char is produced in solid form by dry carbonization, pyrolysis or gasification of biomass, and in slurry form by hydrothermal carbonization of biomass under pressure (recent advances in the utilization of biochar). Bio-char can be used in any particular areas; hence the end users of biochar should considering the chemical and physical characterization of biochar.
However, biochar also can be produced either by direct firing method and non-direct firing method wherein non-direct firing method, the heating source not direct contact with the feedstock and heated externally. The combustion of bio-char happens in a separate chamber and heat is transferred by conduction Furthermore, by using the non-direct method, it produced clean air and no pollution occurred.
Palm oil industry in Malaysia has grown quickly cause the waste of this production to increase. However, with the presence of lignocellulose biomass broadly has created cause the major problem in disposing of the waste. Palm oil biomass has been abundant without applying proper waste management to minimize and recover the energy from waste. Moreover, the palm oil frond that being cut during harvesting is only being left to rot on the ground and this abundance of oil palm frond not fully utilized into a product. It has an alternative used for economical aspect thus should not be disposed of easily. Today, the increase in global warming through the greenhouse gas emission and an increase in the concentration of carbon dioxide in the atmosphere are the greatest threats and challenges faced by mankind. Production of biochar can potentially lead to environment-friendly replacement and enhance sustainability.
Production of biochar was selected for my project as I found that palm oil frond is the highest abundance waste that has the potential to be converted into useful products in environmental sustainability. Furthermore, this palm oil frond is easily found especially after the pruning process. Non-direct firing method was used in my study because it produced clean and dry air and the heater not release carbon dioxide which can be operated in a tightly sealed space.
The objectives of this research are:
1)To study the optimum parameter to prepare bio-char using double jacket pyrolyzer.
2)To evaluate and characterized of palm oil frond bio-char physical characteristics by using SEM, BET, pH meter and UV-Vis Spectroscopy.
Scope of Research
The scopes of this research study are discussed to ensure the objectives of the research are achieved. Firstly, this experiment was conducted under various activation temperature which are 400 ?C, 600 ?C and 800 ?C of heating temperature under slow pyrolysis for 1 hour in double jacket pyrolyzer. From the previous study, production of biochar under slow pyrolysis showed a higher yield of biochar in term of mass and energy. Would be tested for its physical characteristics using Brunaeuer, Emmett, and Teller (BET) method that calculated a specific surface area of biochar by measure the nitrogen gas sorption at 77 K(use of chemical and physical characteristics to investigate). In addition, the bio-char surface morphology was analyzed using Scanning Electron Microscopy (SEM) with an acceleration voltage of 20 kV. Sample preparation involves freeze-drying the samples for 3 days before they were adhered to aluminum stubs using graphite and nickel cement. (use of chemical and physical characteristics to investigate). Bio-char methylene blue (MB) adsorption preparation must be conducted at room temperature and dark space and tested using UV-VIS Spectroscopy at a wavelength of 665 nm (use of chemical and physical characteristics to investigate). The amount of MB adsorbed calculated to determine the suitability as an adsorbent. In order to test for pH, biochar samples were immersed in deionized water with 1 hour of stirring. Most of the journal showed that bio-char possesses common high pH value.
The Significant of Research
The increase in solid waste produced in Malaysia due to palm oil production has caused many problems. Thus, turning the lignocellulosic biomass into biochar has been identified as a way in reducing the abundance of waste from palm oil. As known, existing charcoal has caused the greenhouse gas emission to the environment. Therefore, through biochar production along with the abundance of the biomass has opened the way for mitigation of climate change and improve less fertile soils and increase crop yields.
The procedures of this study were divided into three stages; (1) preparation of palm oil frond samples; (2) production of biochar and (3) analysis of the physical characteristics of biochar. Moreover, this experiment is testing based on physical characteristics of the bio-char palm frond based to determine the specific surface area, the surface morphology of palm frond biomass and biochar, pH of solution and adsorption on MB.
Palm Oil Frond
The palm oil frond used is coming from palm oil estate at Tanjung Langsat, Kuala Selangor. The biochar preparation is from palm frond obtained after the pruning process and basically still in fresh condition.
Methylene Blue (MB)
MB used for the bio-char adsorption study before analyzed using UV-Vis Spectroscopy.
Liquefied Petroleum Gas (LPG)
LPG use for the combustion of the biomass.
Nitrogen gas purge into double jacket pyrolyzer during the pyrolysis process.
Distilled water used to immerse the bio-char sample before taking the pH reading of the solution.
The equipment used in this study is stated in table 3.2 below:
Oven To dry the palm oil frond sample
Cutting mill To mash the dried sample into the powder
Weighing scale To weight the palm oil sample in gram
Double jacket pyrolyzer To produce biochar from biomass
SEM To analyze the surface morphology of biochar and biomass
BET To analyze the specific surface area of the sample
UV-Vis Spectroscopy To determine the adsorption reading of biochar samples
pH meter To determine the pH value of biochar
Figure 3.2: Flow for the process of preparing palm oil biomass, biochar, and testing methods.
Preparation of Palm Oil Frond Samples
At the preparing stage, the palm oil fronds are collected from the estate are cutting into small pieces and dried in the oven for three consecutive days at temperature 70 ?C to remove the moisture content from the samples. The moisture content should be less than 5% to get a better quality of biochar. After the drying process, the dried product is mashed in cutting mill and sieve using 1 mm size of molecular sieves. The mashed product is stored in an airtight plastic bag together with silica gel to remove any present moisture in the mashed sample.
Preparation of biochar
This experiment conduct is a batch experiment. The start-up procedure is done by ensuring the valve and supply wire is connected properly and 500 gram of palm frond biomass is fed into a char combustion chamber located in the middle of double jacketed pyrolyzer. The liquefied petroleum gas (LPG) from the gas cylinder is supplied to the burner located in the separate area from char chamber in pyrolyzer because the indirect method has been applied. The compressor in started to help the combustion process. Then the nozzle of the burner is positioned in its place after the flame already turns into blue color. The pyrolysis temperature should be at 400 ?C, 600 ?C or 800 ?C before starting the time for one hour. The heating rate is used at 20 ?C /min. The temperature indicator is used to indicate the temperature of the process. When the temperature is reached at the desired temperature, nitrogen gas is purged into the double jacket reactor to ensure no or low oxygen in the process. With the presence of oxygen, the biomass will be converted into ash. The valves need to be controlled manually to adjust the flow of nitrogen and LPG purging into the system. If the time has reached 1 hour, the shutdown process is being carried out by close the valve of LPG and nitrogen, shut off the compressor and let the biochar to cool down until temperature reaches at 70 ?C before collecting it.
Analysis of Physical Characteristics
There are four types of physical characteristics analysis to be analyzed and study which is Scanning Electron Microscopy (SEM) for the surface morphology study, Brunaeuer, Emmett and Teller (BET) for specific surface area of porosity, pH reading to determine alkalinity or acidity of solution using pH meter and adsorption of methylene blue tested using UV-VIS Spectroscopy.
Scanning Electron Microscopy (SEM)
SEM analysis used is Hitachi S-4100 FE-SEM operates at 20 kV to analyze the differences of surface morphology of the oil palm frond before and after pyrolysis; which the pores have been carbonized and activated after the carbonization process. The major components of palm frond would be cellulose, hemicellulose, and lignin where lignin has been reported to fuse on pyrolysis and forms macropores of ~25 ?m to ~100 ?m in size. Bio-char porosity consists of micropores ;20 nm, mesopores between 2 – 50 nm and macropores ;50 nm. Micropores will absorb small molecules such as gas while mesopores will absorb large molecules such as color (palm frond biochar production and chatacter). From the previous study, it shows the pores structure formed which result from evaporation and breakdown of the non-carbon compounds in the biomass during pyrolysis. Bio-char has an activator that enlarges its porosity, causing the biochar has more rough surface and irregularity. (charateristics of ac from pyrolysis of OPF)
pH meter used is Model 420 Thermo Orion (Thermo Fisher Scientific pH meter) to analyze the pH of the bio-char suspension. Bio-char sample is immersed in deionized water ratio of 1:2 (w/v) and stirred for 1 hour. (production and characteristics of slow pyrolysis biochar: influence of feedstock type and pyrolysis)
Brunaeuer, Emmett, and Teller (BET)
BET used to measure the surface area of the biochar using Autosorb-1 Surface Area Analyzer (Quantachrome Instruments) at 0.162 nm2 N2 absorption and 77 K. BET theory aims to explain the physical adsorption of gas molecules on a solid surface and serves as the basis for an important analysis technique for the measurement of the specific surface area of a material. For this study, BET analysis is to determine the effectiveness of different process temperature. Higher surface area of biochar will increase the adsorption efficiency of charcoal. Samples were degassed at 100 ?C under continuous nitrogen flow for 24 h prior to analysis. (production and characteristics of slow pyrolysis biochar: influence of feedstock type and pyrolysis)
UV-Vis Spectroscopy used to determine the potential of adsorption for different carbonization temperature to produce palm frond bio-char. First, the samples were dried for one night at 60 ?C in an oven to remove the existing moisture. The concentration used from 3-15 g L-1 at 50 mg L-1 of methylene blue (MB) concentration. Then, to study the adsorption process, the samples are placed in the incubator shaker for 25 ?C, 120 min, and speed 120 rpm. (Adsorption of methylene blue on biochar microparticles derived from different waste materials). The sample is separated by filtration and methylene blue adsorption is determined by UV-Vis Spectroscopy at wavelength 665 nm. (carbonisation activation of oil palm kernel shell to produce ac and methylene blue adsorp).