Waste Management & Research 2015, Vol. 33(4) 303–312 © The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0734242X15576026 wmr.sagepub.com Introduction Malaysia is currently the world’s second-largest exporter of palm oil. Malaysia has contributed about 39% from 50 million tonnes production worldwide during 2007–2011, as shown in Figure 1 (USDA, 2012). However, the industry also produces about 51 million tonnes of waste per annum as lignocelluloses bio- masses. A total of 5 million tonnes per annum of it is palm shell (MPOB, 2014). The fundamental principles of waste manage- ment are to minimise and recycle the waste, recover the energy and finally dispose the waste. These principals apply to agro-industrial wastes, such as palm oil residues, as they do to municipal waste (Abdullah and Sulaiman, 2013). Thus, oil palm industries in Malaysia are con- verting them to moulded oil palm product and palm shell acti- vated carbon (PSAC) (MPOB, 2014). However, as carbon molecular sieve, only palm shell carbon molecular sieve (PSCMS) has been reported hitherto. Unfortunately, the feasibil- ity of using waste biomasses from the oil palm industry as a pre- cursor for PSCMS production is yet to be successfully explored and commercialised. Activated carbon (AC) is a form of carbon with a high degree of porosity and extended inter-particulate surface area (Luv et al., 2013; Vanreppelen et al., 2014). ACs are obtained from various carbonaceous substances and used in many applications, for example gas purification, gold purification, metal extraction, water purification, medicine, sewage treatment, air filters in gas masks and filter masks, filters in compressed air and many others. ACs are also famous for their capacity in removing pollutant gases, such as carbon dioxide, hydrogen sulphide, nitrogen oxides, sulphur dioxide and volatile organic compounds (Cheremisinoff and Cheremisinoff, 1993; Luv et al., 2013). Thus, ACs are of interest to many industries. A recent study by Roskill information studies has forecasted that AC could see world consumption double in 4 years, i.e. during 2013 to 2017 (Roskill, 2014). Hence, sustainable production of AC throughout the world is nec- essary. Commercial ACs are manufactured from various carbona- ceous precursors, such as lignite and coal (~42%), peat (~10%), wood (~33%) and coconut shell. At present, agricultural Biomass-based palm shell activated carbon and palm shell carbon molecular sieve as gas separation adsorbents Sumathi Sethupathi 1 , Mohammed JK Bashir 1 , Zinatizadeh Ali Akbar 2 and Abdul Rahman Mohamed 3 Abstract Lignocellulosic biomass has been widely recognised as a potential low-cost source for the production of high added value materials and proved to be a good precursor for the production of activated carbons. One of such valuable biomasses used for the production of activated carbons is palm shell. Palm shell (endocarp) is an abundant by-product produced from the palm oil industries throughout tropical countries. Palm shell activated carbon and palm shell carbon molecular sieve has been widely applied in various environmental pollution control technologies, mainly owing to its high adsorption performance, well-developed porosity and low cost, leading to potential applications in gas-phase separation using adsorption processes. This mini-review represents a comprehensive overview of the palm shell activated carbon and palm shell carbon molecular sieve preparation method, physicochemical properties and feasibility of palm shell activated carbon and palm shell carbon molecular sieve in gas separation processes. Some of the limitations are outlined and suggestions for future improvements are pointed out. Keywords Palm shell activated carbon, palm shell carbon molecular sieve, gas adsorption, biomass, adsorbent, carbon 1 Faculty of Engineering and Green Technology, Universiti Tunku Abdul Rahman, Jalan Universiti, Bandar Barat, Malaysia 2 Water and Wastewater Research Center (WWRC), Razi University, Kermanshah, Iran 3 School of Chemical Engineering, Universiti Sains Malaysia, Nibong Tebal, Malaysia Corresponding author: Sumathi Sethupathi, Faculty of Engineering and Green Technology, Universiti Tunku Abdul Rahman, Jalan Universiti, Bandar Barat, Kampar, Perak, Malaysia. Email: sumathi@utar.edu.my 576026WMR 0 0 10.1177/0734242X15576026Waste Management & ResearchSethupathi et al. research-article 2015 Mini-review Article