BIOCHAR PRODUCTION FROM OIL PALM WASTES VIA SLOW PYROLYSIS PROCESS AND ITS CHARACTERISTICS STUDY

 

PENGHASILAN BIOARANG DARIPADA SISA KELAPA SAWIT MELALUI PROSES PIROLISIS PERLAHAN DAN KAJIAN CIRI-CIRINYA

 

ABSTRAK

 

Objektif kajian ini adalah untuk menghasilkan bioarang daripada tandan buah kosong kelapa sawit (EFB) dan tempurung kelapa sawit (OPS) melalui proses pirolisis perlahan berskala makmal, menyiasat ciri - ciri bioarang yang dihasilkan daripada pelbagai keadaan bahan mentah dan proses pirolisis, dan membandingkan bioarang yang dihasilkan daripada EFB dan OPS. Analisis awal telah dijalankan terhadap kedua - dua bahan mentah untuk mengkaji ciri - ciri bahan. Pra-rawatan basuhan menggunakan air telah dilakukan terhadap bahan mentah EFB untuk mempelbagaikan kandungan abu bahan mentah. Untuk bahan mentah EFB, kesan tempoh masa dan kandungan abu bahan mentah terhadap hasil bioarang dan ciri - cirinya telah disiasat. Tempoh masa telah diubah dari 0.5 jam hingga 4.0 jam, sementara suhu dan kadar pemanasan masing - masing ditetapkan pada 550 °C dan 5 °C/min. Bahan mentah EFB yang mempunyai kandungan abu dalam linkungan 1.60 hingga 5.29 mf wt % telah dipirolisis pada suhu 550 °C dan kadar pemanasan 5 °C/min selama 1 jam. Untuk bahan mentah OPS, kesan suhu dan tempoh masa terhadap hasil bioarang dan ciri - cirinya telah dikaji. OPS telah dipirolisis pada 6 suhu yang berbeza; 400 °C, 450 °C, 500 °C, 550 °C, 600 °C and 650 °C pada kadar pemanasan 5 °C/min selama 1 jam.

 

Seterusnya, tempoh masa diubah dari 0.5 jam hingga 4.0 jam, sementara suhu dan kadar pemanasan masing - masing ditetapkan pada 550 °C dan 5 °C/min. Hasil bioarang, cecair dan gas ditentukan. Bioarang dianalisa melalui analisis proksimat, analisis unsur, kajian morfologi permukaan dan analisis luas kawasan permukaan BET. Didapati bahawa tempoh masa memberikan pengaruh kecil terhadap hasil produk untuk kedua - dua bahan mentah EFB dan OPS. Tempoh masa optimum bagi penghasilan bioarang daripada bahan mentah EFB dan OPS adalah masing - masing pada 1.0 jam dan 4.0 jam. Apabila suhu pirolisis ditingkatkan, hasil bioarang OPS berkurangan manakala kandungan karbon tetap dan luas kawasan permukaan BET meningkat. Pengurangan kandungan abu bahan mentah EFB melalui proses pra-rawatan basuhan mendorong kepada pengurangan hasil bioarang dan peningkatan kandungan karbon tetap dan luas kawasan permukaan BET bioarang. Proses pirolisis perlahan bahan mentah OPS menghasilkan peratusan bioarang yang lebih tinggi berbanding bahan mentah EFB untuk tempoh masa dari 0.5 jam hingga 4.0 jam. Analisis ciri - ciri bioarang menunjukkan bioarang OPS mempunyai kandungan karbon tetap dan luas kawasan permukaan BET yang lebih tinggi berbanding bioarang EFB. Kajian ini menunjukkan bioarang OPS yang dihasilkan daripada proses pirolisis perlahan berskala makmal mempunyai kualiti yang lebih baik berbanding bioarang EFB.

 

 

 

 

 

BIOCHAR PRODUCTION FROM OIL PALM WASTES VIA SLOW PYROLYSIS

 

PROCESS AND ITS CHARACTERISTICS STUDY

 

 

 

ABSTRACT

 

The objectives of this study are to produce biochar from oil palm empty fruit bunches (EFB) and oil palm shell (OPS) via laboratory-scale slow pyrolysis system, investigate the characteristics of biochar produced from various feedstock and pyrolysis conditions, and compare the biochar produced from EFB and OPS. The preliminary analysis was performed on both feedstocks to investigate their properties. The water washing pre-treatment was carried out on the EFB feedstock to vary the ash content of the feedstock. For the EFB feedstock, the impacts of residence time and feedstock ash content on the biochar yield and characteristics were investigated. The residence time was varied from 0.5 h to 4.0 h, while the temperature and heating rate were fixed at 550 °C and 5 °C/min respectively. The EFB feedstock in the range of 1.60 to 5.29 mf wt % of ash content were pyrolyzed at 550 °C and 5 °C/min heating rate for 1 h residence time. For the OPS feedstock, the impacts of temperature and residence time on the biochar yield and characteristics were studied. The OPS were pyrolyzed at 6 different pyrolysis temperature; 400 °C, 450 °C, 500 °C, 550 °C, 600 °C and 650 °C at 5 °C/min heating rate for 1 h residence time. The residence time was then varied from 0.5 h to 4.0 h, while the temperature and heating rate were fixed at 550 °C and 5 °C/min respectively.

 

The biochar, liquid and gas yields were determined. The biochar was analyzed via proximate and elemental analysis, surface morphology study and BET surface area analysis. It was observed that the residence time had little influence on the product yields for both EFB and OPS feedstock. It was found that 1.0 h and 4.0 h are the optimum residence time for EFB and OPS biochar production respectively. As the pyrolysis temperature elevated, the OPS biochar yield reduced while the fixed carbon content and BET surface area increased. The reduction of ash content in the EFB feedstock via water washing pre-treatment led to a decrease of biochar yield and corresponding increase of biochar’s fixed carbon content and BET surface area. The slow pyrolysis of OPS feedstock produced higher biochar yield as compared to EFB feedstock for varied residence times between 0.5 h to 4.0 h. The analysis of biochar characteristics found that the OPS biochar contain higher fixed carbon content and has larger BET surface area as compared to the EFB biochar. This study shows that OPS biochar produced from the laboratory-scale slow pyrolysis process has better quality as compared to the EFB biochar.