Comparison between Properties of Biochar Produced by Traditional and Controlled Pyrolysis

Abstract

Biochar is usually produced from crop residues (feedstock) by pyrolysis process under controlled conditions in specialized reactors. The characterization of biochar properties produced under field condition is limited. The objective of this study was to compare the physicochemical properties of biochar produced from two feedstocks; sugarcane bagasse feedstock (SCBF) and rice husk feedstock (RHF), under traditional field conditions (primitive) and controlled conditions. The temperature of traditional pyrolysis process was kept around 500 °C. However pyrolysis temperature under controlled conditions was repeated at 450 °C and 550 °C. In general, the results showed that increasing pyrolysis temperature decreased biochar yield and increased volatile matter, total surface area and total pore volume which were higher in RHBs than in SCBBs, the pHs of both biochars were to the alkaline range, ash and Si percentages of RHBs were higher than that of SCBBs. Furthermore, the C percentage which was higher in SCBB than in RHB. The FR-IR spectral showed that the presence of free OH group and C-H stretch in both feedstocks disappeared in produced biochars under different pyrolysis conditions. The SEM images showed the presence of longitudinal pores in SCBF while SCBB (550 °C) contained longitudinal structure and fewer micropores, while the images of the RHF showed disturbed order of elongated pores which have been changed to developed pores in RHB (550 °C and traditional). The data of XRD analysis of SCBF indicated the presence of cellulose and disappeared in its three biochars while, XRD data of RHF and RHBs indicate the presence of amorphous silica and quartz. Both biochars produced in the field using traditional pyrolysis unit showed approximately biochar properties as those produced under controlled condition (550 °C).

Potential bioremediation of lead and phenol by sunflower seed husk and rice straw-based biochar hybridized with bacterial consortium: a kinetic study

“…The pH values of studied biochars indicate that both materials were alkaline and relatively close with a difference value of 0.18 unit. The high pH values of the produced biochar materials could be related to concentrations of non-pyrolyzed mineral elements as well as organic matrix decomposition 15 . Additionally, the EC of both biochars were less 1 dS m −1 .…”

“…The ash content of both biochars (SHB and RSB) was determined by dry incineration at 600 °C for 12 h in the air using a muffle furnace. The ash percentage was calculated as follows: 15 where W i and W f are the initial and final weight of materials before and after burning (g), respectively.…”

“…To determine biochar pH and EC, one percent of biochar-water suspension (w/v) was agitated for 20 min at 90 °C and the pH was measured using a Professional Multi-Parameter (Bench Meter with GLP—AD8000 model) 15 . Cation exchange capacity of both biochars was measured as defined by Gaskin et al 20 using the method of a modified ammonium‐acetate compulsory (CEC-NH 4 ) displacement method.…”

“…Several advantages and disadvantages of these materials have been reported related to biodegradable resistance, cost, fixed difficulty, and mechanical strength 10 , 12 Recently, carbon-based materials have attracted great attention, especially those derived from agricultural wastes such as biochar. Biochar is a solid by-product material produced by the pyrolysis process of organic waste in an oxygen-limited environment 13 – 15 . It is a black carbon-rich substance with unique properties for various applications, such as high cation exchange capacity (CEC), large surface area, high porosity, functional groups, and stability 14 , 16 .…”

Impact of agricultural waste on the shrink–swell behavior and cracking dynamics of expansive soils

“…Table 1 also indicates that organic amendments derived from rice husk had higher ash content than those derived from sugarcane bagasse. This could be due to the higher amount of Si in rice husk (El-gamal et al 2017). Si is a major component in the chemical structure of rice.…”