Preparation of activated carbon from EFB by microwave-assisted KOH activation for methylene blue adsorption (Foo and Hameed 2011), PKS by phosphoric acid impregnation (Lim et al. 2010), PKS by ZnCl2 and physical activation for methane adsorption (Arami-Niya et al. 2010; Abbas and Daud 2009), PKS to remove lead ions from aqueous solutions (Issabayeva et al. 2006), PKS for basic dye adsorption (Jumasiah et al. 2006), OPT by phosphoric acid impregnation (Hussein et al. 2001), PKS by chemical activation with K2CO3 (Adinata et al. 2007) and PKS by ZnCl2 impregnation for the removal and recovery of residual oil from POME (Ngarmkam et al. 2011) have been reported. The results from Arami-Niya et al. (2010) indicated a significant increase in methane adsorption after physico-chemical activation. Preparation of palm oil empty fruit bunch-based activated carbon for removal of 2,4,6-trichlorophenol has also proven feasible (Hameed et al. 2009). Catalytic char­acteristics of activated carbon manufactured from PKS for methane decomposition were studied using a thermobalance (Abbas and Daud 2009).

The development of microporosity for the oil-palm-shell activated carbon would lead to potential applications in gas-phase adsorption for the removal of air pollut­ants (Guo and Lua 2002) . Tan and Ani (2004) utilised PKS to prepare carbon molecular sieve (CMS) by carbonisation for air separation and concluded that PKS is a highly potential material for CMS. Other studies (Ahmad et al. 2008; Adinata et al. 2007; Sumathi et al. 2010) have also utilised PKS and other OPW as activated carbon for gas removal. Some other applications of OPW for carbon materials include high porosity carbon powder from OPW as an adsorbent (Alam et al. 2009; Tan et al. 2010), carbon glassy from PKS for electrodes (Aroua et al. 2008), green nanoparticles from POME (Gan et al. 2012) and electrical carbon brushes as conductors.