Palm Stone Research Articles

Activated carbon prepared from oil palm stone by one-step CO2 activation for gaseous pollutant removal

Abstract The feasibility of preparing activated carbons from oil palm stones by one-step CO2 activation was studied. These oil palm stones are major solid wastes generated from palm-oil processing mills. Experimental results showed that the particle size of the starting material and heating rate appeared to have no significant effects on the BET surface areas of the activated carbons but CO2 flow-rate had a significant influence. Increasing the heating rate resulted in slight reductions in the micropore surface areas. The BET and micropore surface areas of the activated carbons were also found to be dependent on the activation temperature and the hold time. The optimum conditions for activation were for an activation temperature of 850°C and a hold time of 2 h, at which the BET and micropore surface areas were found to be maximum at 1410 and 942 m2 g−1 respectively. The pore size distributions of the activated carbon also confirmed these conditions. The development of microporosities in these activated carbons suggest their potential applications in gaseous pollutant adsorption. From chemical characterisation, the activation temperature was found to have an insignificant effect on the inorganic components of the activated carbons but possible effects on their surface functional groups. The amounts of NO2 adsorbed onto the oil-palm-stone activated carbons and a commercial one were measured during adsorption tests. The relationship between the amount of gas adsorbed and the BET surface area of the activated carbon indicated that the adsorptive capacity was linearly proportional to the surface area.

Characterization of chars pyrolyzed from oil palm stones for the preparation of activated carbons

Chars pyrolyzed from oil palm stones, an abundant palm-oil mill solid waste, for the preparation of activated carbons were characterized in this paper. An ultra-pycnometer and a mercury intrusion porosimeter were used to measure the solid and apparent densities of the samples, respectively and a thermogravimetric analyzer was used for proximate analysis. The effects of pyrolysis temperature and retention time on the char yield and BET surface area of the chars were investigated. The optimum condition for pyrolysis was found to be at a pyrolysis temperature of 800°C for a retention time of 3 h. The SEM micrographs of the char surfaces verified the presence of porosity. The experimental results showed that it was feasible to prepare chars with sufficient densities and relatively high porosities from oil palm stones for the further preparation of activated carbons.

Wisior opasany taśmami brązowymi z cmentarzyska kultury wielbarskiej i zagadnienie występowania bezoarów

A pendant encircled with bronze bands was found in 1984 during the excavations of barrow 26 in the cemetery at Odry. The grave, which has yielded the pendant, is dated to the second half of the 1st century AD. At first the object in question was thought to be a palm stone (Phoenix sylvatica). Thorough analysis, however, has shown that it is a bezoar, i.e. a globular formation produced in the stomachs of ruminants. The bezoar from Odry was composed of the hair of lynx, hare and mouse. Bezoars were worn as amulets all over medieval and modern Europe. They usually served as protection against all sorts of illnesses and complaints, notably poisoning. The find from Odry would thus represent the earliest antidote known.