Supporting Clean Energy in the ASEAN: Policy Opportunities from Sustainable Aviation Fuels Initiatives in Indonesia and Malaysia

Sustainable aviation fuels is a strategic long-term solution for zero-carbon aviation industry by 2050, thus underscoring the need to accelerate the deployment through reforms in the relevant key areas. Aligned to the agenda, this paper aims to study the policy opportunities for drop-in sustainable aviation fuel (SAF) deployment in the ASEAN by considering the initiatives undertaken. by Indonesia and Malaysia. Four areas are used as coding framework to assess the current status, challenges, and policy opportunities, namely (1) policy, strategy, and reforms; (2) standards and certification system; (3) economic instruments; and (4) international integration. First, the current status and challenges within each country is assessed. Indonesia has shown a more command-and-control approach with an upfront SAF blending mandate. However, it needs to be supported by several compliance measures. Malaysia, on the other hand, has conducted country assessments but no SAF-specific policy has been issued yet. Both countries still lack the economic instruments, while international integration is still relatively under-explored with only limited inter-regional partnerships. As the biggest palm-oil producing countries, Indonesia and Malaysia possess enormous potentials to lead the region in deploying SAF, thus more initiatives are urged

Process optimization of carbon dioxide adsorption using nitrogen-functionalized graphene oxide via response surface methodology approach

This paper presents a response surface methodology approach in the optimization of the carbon dioxide temperature-programmed adsorption process using a new material referred as nitrogen-functionalized graphene oxide. This material was synthesized by loading nitrogen groups to graphene oxide using aqueous ammonia in supercritical condition. Later on, it was utilized as a sorbent for carbon dioxide adsorption. This process was optimized by implementing a response surface methodology coupled with a Box-Behnken design for the effects of three factors: adsorption temperature, carbon dioxide flow rate, and the amount of adsorbent. In analyzing the response surface, a model equation was generated based on the experimental data by regression analysis. This model equation was then utilized to predict optimum values of response. Furthermore, response optimizer was also conducted in identifying factor combination settings that jointly optimize the best response. © 2018, Gadjah Mada University. All rights reserved

Synthesis and characterization of hybrid composite aerogels from alginic acid and graphene oxide

Aerogels are one class of solid adsorbents that are gaining considerable attention because of their very high porosity, high specific surface area, and extremely low density. However, most aerogels being studied and used recently are synthetic in nature, which are usually mesoporous silica and metal-organic frameworks (MOFs). As research focus is geared towards sustainable engineering, it is desired to utilize biomass to synthesize aerogels. This study thus aims to produce alginic acid-graphene oxide hybrid composite aerogels and compare them with its existing synthetic counterparts. Alginic acid (AA) is an abundant marine biopolymer that easily forms gels, while graphene oxide (GO) is a nanomaterial consisting of many functional groups. Aerogels made up of AA and GO were successfully synthesized using a sol-gel method. The hydrogel was converted into an aerogel by drying with supercritical carbon dioxide. The percentage of graphene oxide was varied from 0 to 20%. The aerogels were characterized by scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and nitrogen adsorption-desorption measurements. The addition of GO increased the specific surface area of the aerogel up to a certain point, after which it decreased. The 10% GO-AA aerogel showed the most favourable porosity characteristics with a specific surface area of 177.26 m2/g and average pore diameter of 53.2 nm. There had been no observable difference in the thermal behaviour of the aerogels with a change in the concentration of graphene oxide. © Published under licence by IOP Publishing Ltd

Synthesis and characterization of nitrogen-functionalized graphene oxide in high-temperature and high-pressure ammonia

A novel and efficient approach to the synthesis of nitrogen-functionalized graphene oxide (GO) using aqueous ammonia, NH3 (aq.), under high-temperature and high-pressure conditions was investigated. Nitrogen groups (N-groups) were incorporated in GO in different ways; by replacing the carbon (C) atoms and reacting with the oxygenated functionalities present in GO. Reaction mechanisms were proposed, showing how N-groups were attached to GO. Functionalization was confirmed using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR) spectroscopy and elemental analysis (EA). Raman spectroscopy, X-ray diffraction spectroscopy (XRD), and scanning electron microscopy (SEM) were employed to further characterize GO modification. Functionalization was carried out to increase GO adaptability to a wide range of applications, including carbon dioxide (CO2) capture and electrochemical oxygen reduction as reported. © The Royal Society of Chemistry

Biological phosphate removal using a degradable carbon source produced by hydrothermal treatment of excess sludge

The possibility of reusing excess sludge treated by hydrothermal reaction for the purpose of improving the efficiency of the enhanced biological phosphate removal (EBPR) process was investigated. Excess sludge from a fish-processing industry located in Japan was treated in high-temperature and high-pressure water, at a reaction temperature ranging from 200 to 400ºC, a pressure of 1.8 to 30MPa and a constant reaction time of 7 min. For the conditions tested, the results showed that when the reaction temperature was increased the content of readily biodegradable substrate in the total COD Cr increased. In addition, the amount of some volatile fatty acids (VFAs) produced by the hydrothermal reaction increased as reaction temperature increased. From the phosphate release tests under anaerobic conditions, it was possible to demonstrate that not only the VFAs, but also the readily and slowly biodegradable substrates are used as potential carbon source by the phosphate-accumulating organisms (PAOs)