Rubber Seed Shell Biochar Sulphonation: A Process Optimization and Conditions’ Effect Analysis
DOI:
https://doi.org/10.37933/nipes.e/4.2.2022.12Abstract
This study investigated the sulphonation process of biochar
prepared from the carbonization of rubber seed shells. The biochar
was sulphonated using 98% concentrated sulphuric acid, and the
total acid density on the surface of the sulphonated biochar was
determined using acid-base back titration. The effect of
sulphonation process variables including acid-to-biochar ratio,
sulphonation time, and sulphonation temperature on the biochar’s
total acid density was studied. The process was optimized using
response surface methodology with a central composite design. The
results revealed that a quadratic polynomial model best described
the sulphonation process of rubber seed shell biochar with no
significant lack of fit. An optimum total acid density of 3.08 mmol/g
was obtained under an acid-to-biochar ratio of 10:1 (v/w),
sulphonation time of 4.00 hr., and sulphonation temperature of
98.08 oC. The large total acid density of the rubber seed shells
biochar makes it a potential esterification catalyst for biodiesel
production.
