Hydrogen from renewable palm kernel shell via enhanced gasification with low carbon dioxide emission

Hydrogen economy has become more attractive with the energy crises and environmental issues associated with fossil fuel utilization more so with the discovery that hydrogen can be produced from renewable biomass. This provides good prospects to Malaysia that generates abundant palm wastes. Nevertheless, there is still limited knowledge on kinetics parameters for hydrogen production from palm kernel shell (PKS) gasification. Hence, this work aims to develop a mathematical model that is able to describe the kinetics of steam gasification of PKS with in situ CO₂ capture while considering tar formation. A mean-squared error minimization approach has been used to estimate the kinetics parameters of the gasification process. Using the calculated kinetics parameters the process efficiencies are profiled with respect to the effect of gasification temperature, steam/biomass ratio and sorbent/biomass ratio. The parametric study indicates that the three variables promote hydrogen production at different degree of influence. This developed model can be further extended to incorporate optimization study on the potential clean production of hydrogen from PKS.     

Effect of lignin on mechanical,biodegradability, morphology,and thermal properties of polypropylene/polylactic acid/lignin biocomposite

ABSTRACT

The effects of lignin on mechanical, biodegradability, morphology, and thermal properties of PP/PLA/lignin were investigated. PP/PLA/lignin film were manufactured by adding PP, PLA, lignin and compatibilizer into rheomix at 200°C, at 70?rev?min^?1 for 30?minthen pressed using Hydraulic Hot Press at 200°C–210°C, at 6 bar for 20?min. The functional groups of PP/PLA/lignin were analyzed using FTIR. The surface morphology, mechanical properties and thermal stability was measured by SEM, tensile strenght and TGA respectively. TThe FTIR intensity of vibration peak of –CH₃?cm^-1 from PP/lignin and PP/PLA/lignin at 997–993, 1458–1451 and 2966–2904?cm^-1 was lower than neat PP. The addition of lignin into PP/lignin, PLA/lignin and PP/PLA/lignin can reduce tensile strength and elongation at break. The thermal stability PP/PLA/lignin was lower than the PP/lignin but higher compared to PP/PLA biocomposites. The biodegradability of PP/PLA/lignin biocomposites was two times higher than that of PP/lignin.     

Synthesis and characterization of green urethane non-isocyanate from oleic acid for wood composite application

Conventional polyurethane (PU) is usually synthesized by a reaction between isocyanate and polyol. The use of isocyanate compounds is associated with significant health and environmental problems. Therefore, it is necessary to develop an environmentally friendly alternative method for manufacturing PUs without isocyanate routes. The aim of this research work was to synthesize green urethane from oleic acid, which included the following three stages: the synthesis of epoxidized oleic acid (EOA), the synthesis of carbonated oleic acid (COA), and the synthesis of green urethane from oleic acid (UOA). The resulting product was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR) analyses, and by determining the iodine number, oxirane number, and hydroxyl value. The results of FTIR and NMR showed that EOA was successfully synthesized. The optimum COA synthesis process was obtained on TBAB catalyst usage of 1% (wt/wt) at 140°C for 48 h with a 500-rpm stirring rate and CO₂ gas flow rate of 0.2 mL/min with the resulting COA oxirane value of 0.00. The optimum condition of UOA synthesis through the aminolysis process resulted in the use of LiCl of 19.8% (wt/wt) at 70°C for 3 h with a stirring speed of 1200 rpm with a UOA hydroxyl number generated of 237.93 mg/mL.     

Integrated catalytic adsorption (ICA) steam gasification system for enhanced hydrogen production using palm kernel shell

This paper investigates the integrated catalytic adsorption (ICA) steam gasification of palm kernel shell for hydrogen rich gas production using pilot scale fluidized bed gasifier under atmospheric condition. The effect of temperature (600–750 °C) and steam to biomass ratio (1.5–2.5 wt/wt) on hydrogen (H₂) yield, product gas composition, gas yield, char yield, gasification and carbon conversion efficiency, and lower heating values are studied. The results show that H₂ hydrogen composition of 82.11 vol% is achieved at temperature of 675 °C, and negligible carbon dioxide (CO₂) composition is observed at 600 °C and 675 °C at a constant steam to biomass ratio of 2.0 wt/wt. In addition, maximum H₂ yield of 150 g/kg biomass is observed at 750 °C and at steam to biomass ratio of 2.0 wt/wt. A good heating value of product gas which is 14.37 MJ/Nm³ is obtained at 600 °C and steam to biomass ratio of 2.0 wt/wt. Temperature and steam to biomass ratio both enhanced H₂ yield but temperature is the most influential factor. Utilization of adsorbent and catalyst produced higher H₂ composition, yield and gas heating values as demonstrated by biomass catalytic steam gasification and steam gasification with in situ CO₂ adsorbent.     

FTIR and thermal analyses of intermolecular interactions in poly(trimethylene terephthalate)/phenoxy blends

Intermolecular interactions in the blends of poly(trimethylene terephthalate)/phenoxy resin of bisphenol A prepared by melt mixing in a microcompounder were studied using Fourier transform infrared (FTIR) spectroscopy and thermal analysis. The FTIR results revealed the characteristic bands of the blend constituents along with the bands showing interassociated, self‐associated, and nonassociated hydrogen bonding in the blends. It was found that the self‐associated hydrogen bonds in the blends were favorable over the interassociated bonds. On the other hand, using the melting point depression, the interaction parameter of the blends was calculated to be about 0.047. The positive value of the interaction parameter and low degree of interassociated hydrogen bonding in the blends suggest the immiscibility of the blends, which is confirmed by scanning electron microscopy observations as well as dynamic mechanical analysis. However, for chemically reacted compositions, the blends were changed to homogenous systems. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers     

Utilization of BA (boiler ash) as catalyst for transesterification of palm olein

BA (boiler ash) (empty fruit bunch ash) was used as a source of pseudo-homogeneous base catalyst for transesterification of palm olein. BA successfully transesterified palm olein at mild reaction conditions (3 wt.% dried BA, 15:1 methanol:oil molar ratio, reaction temperature of 60 °C and reaction time of 30 min) to produce 90% methyl esters. Although BA works very well as a catalyst for transesterification, it is not reusable as the active species in the catalyst tend to leach out of the system during reaction. BA was prepared for transesterification by drying in oven at 105 ± 2 °C to constant weight.     

High Flexibility of RNaseH2 Catalytic Activity with Respect to Non-Canonical DNA Structures

Ribonucleotides misincorporated in the human genome are the most abundant DNA lesions. The 2′-hydroxyl group makes them prone to spontaneous hydrolysis, potentially resulting in strand breaks. Moreover, their presence may decrease the rate of DNA replication causing replicative fork stalling and collapse. Ribonucleotide removal is initiated by Ribonuclease H2 (RNase H2), the key player in Ribonucleotide Excision Repair (RER). Its absence leads to embryonic lethality in mice, while mutations decreasing its activity cause Aicardi–Goutières syndrome. DNA geometry can be altered by DNA lesions or by peculiar sequences forming secondary structures, like G-quadruplex (G4) and trinucleotide repeats (TNR) hairpins, which significantly differ from canonical B-form. Ribonucleotides pairing to lesioned nucleotides, or incorporated within non-B DNA structures could avoid RNase H2 recognition, potentially contributing to genome instability. In this work, we investigate the ability of RNase H2 to process misincorporated ribonucleotides in a panel of DNA substrates showing different geometrical features. RNase H2 proved to be a flexible enzyme, recognizing as a substrate the majority of the constructs we generated. However, some geometrical features and non-canonical DNA structures severely impaired its activity, suggesting a relevant role of misincorporated ribonucleotides in the physiological instability of specific DNA sequences.