Noridah Osman

Production of a bioflocculant from Aspergillus niger using palm oil mill effluent as carbon source

This study evaluated the potential of bioflocculant production from Aspergillus niger using palm oil mill effluent (POME) as carbon source. The bioflocculant named PM-5 produced by A. niger showed a good flocculating capability and flocculating rate of 76.8% to kaolin suspension could be achieved at 60 h of culture time. Glutamic acid was the most favorable nitrogen source for A. niger in bioflocculant production at pH 6 and temperature 35 °C. The chemical composition of purified PM-5 was mainly carbohydrate and protein with 66.8% and 31.4%, respectively. Results showed the novel bioflocculant (PM-5) had high potential to treat river water from colloids and 63% of turbidity removal with the present of Ca(2+) ion.

Analysis of DCM extractable components from hot-pressed hybrid poplar

Abstract The effects of thermal compression on the organic-soluble material of a uniform wood substrate, hybrid poplar (clone OP-367), has been studied. Poplar veneers were preconditioned to 0% or 8% moisture content and subsequently hot pressed at 150°C, 200°C, and 250°C. The dichloromethane (DCM) extracts were characterized by various hyphenated analyses [gas chromatography-mass spectrometry (GC-MS), analytical pyrolysis (Py-GC-MS), electrospray ionization-mass spectrometry (ESI-MS), and gel permeation chromatography (GPC)]. The yields and composition of extractable compounds were markedly influenced by treatment at 250°C compared to those obtained at lower temperatures. Most importantly, the organic extracts contained a significant portion of lignin-derived compounds after treatment at 250°C.

Linear viscoelasticity of hot-pressed hybrid poplar relates to densification and to the in situ molecular parameters of cellulose

Key messageHot pressing leads to changes in wood water sorption properties, linear viscoelastic behavior, and chemistry. In hot-pressed hybrid poplar, storage modulus linearly correlates with cellulose apparent crystallinity index and degree of polymerization, revealing the impact of cellulose hydrolysis on wood viscoelasticity during hot pressing.ContextHeat treatment and densification during hot pressing are known to alter wood chemical, physical, and viscoelastic properties. Interrelationships between these properties and their changes during hot pressing are, however, unknown. They are expected to play a significant role on mat consolidation during the manufacture of wood-based composites.AimsThis study aims (1) to characterize the impact of hot pressing on the physical, viscoelastic, and chemical properties of hybrid-poplar wood and (2) to assess possible relationships between these properties.MethodsDry and moist wood samples were hot-pressed under various conditions of temperature. Specific gravity, water sorption isotherms, and dynamic viscoelastic properties of hot-pressed wood were measured together with cellulose apparent crystallinity and molecular weight. Possible relationships between these properties were assessed with statistical analyses.ResultsWood specific gravity, sorption isotherm, dynamic moduli, and cellulose crystallinity were all affected by the hot-pressing conditions. The viscoelastic response of hot-pressed wood was found to relate not only to the extent of densification but also to in situ molecular properties of cellulose. Cellulose apparent crystallinity index and degree of polymerization in hot-pressed wood linearly correlated with storage modulus, revealing the importance of cellulose hydrolysis during hot pressing on wood viscoelastic response.ConclusionDuring hot pressing, wood cellulose hydrolysis appears to govern the viscoelastic response, in addition to wood densification.

Characterizations of Bio-char from Fast Pyrolysis of Meranti Wood Sawdust

In this research, Meranti wood sawdust (MWS) was pyrolyzed in a fixed bed drop- type pyrolyzer under an inert condition. The first part of the study is to determine the influence of pyrolysis temperature (450, 500 and 550 °C) on the yield of pyrolysis products. Pyrolysis of the waste MWS material generated the highest amount of bio-char with approximately 38 wt.% at pyrolysis temperature of 450 °C. Next, the char product (from pyrolysis at 450 °C) was analyzed to compare its characteristics with the raw MWS feedstock. The major component of the char is carbon element, significantly contributed to its high calorific value. TGA profile shows the MWS char could withstand high temperature of up to 400 °C. Under extensive heating, particle size of the bio-char from SEM images decreased due to breakage and shrinkage processes.

Physiochemical Properties of Pyrolysis Oil Derived from Fast Pyrolysis of Wet and Dried Rice Husk in a Free Fall Reactor

Rice husk is considered as a massive agricultural lignocellulosic biomass residue for the production of bio-based fuels and chemicals products. The purpose of this study is to investigate the physiochemical properties of the pyrolysis-oil derived from wet and dried rice husk fast pyrolysis process. The experiments were performed in a drop type fixed-bed pyrolyzer at the pyrolysis temperature of 350 to 600 °C. The products, char, pyrolysis-oil and gas, yield are investigated. The pyrolysis-oil derived from dried rice husk contained higher Carbon and Hydrogen and less oxygen contents than the pyrolysis-oil obtained from wet rice husk. FT-IR results showed the oxygenated compounds present in both pyrolysis-oil. The pyrolysis oil from dried rice husk has higher concentration of hydrocarbons as compared to wet rice husk pyrolysis-oil. The dried rice husk pyrolysis-oil produced more phenols and less carboxylic acid as compared to wet rice husk pyrolysis-oil at 500 °C. More volatile released in dried rice husk conversion produced more volatile compounds. These findings suggest that the original moisture present in biomass samples is the major influencing parameter on the thermal degradation of biomass during fast pyrolysis process.

Three types of Marine microalgae and Nannocholoropsis oculata cultivation for potential source of biomass production

Microalgae have been vastly investigated throughout the world for possible replacement of fossil fuels, besides utilization in remediation of leachate, disposal of hypersaline effluent and also as feedstock for marine organisms. This research particularly has focused on locally available marine microalgae sample and Nannochloropsis oculata for potential mass production of microalgae biomass. Biomass produced by sample 1 and sample 2 is 0.6200 g/L and 0.6450 g/L respectively. Meanwhile, sample 3 and N. oculata has obtained maximum biomass concentration of 0.4917 g/L and 0.5183 g/L respectively. This shows that sample 1 and sample 2 has produced approximately 20% higher biomass concentration in comparison to sample 3 and N. oculata. Although sample 3 and N. oculata is slightly lower than other samples, the maximum biomass was achieved four days earlier. Hence, the specific growth rate of sample 3 and N. oculata is higher; meanwhile the specific growth rate of N. oculata is the highest. Optical density measurements of all the sample throughout the cultivation period also correlates well with the biomass concentration of microalgae. Therefore, N. oculata is finally selected for utilization in mass production of microalgae biomass.

Pyrolyzed Waste Engine Oil Properties by Microwave-Induced Reactor

This study investigates the properties of pyrolyzed waste engine oil to determine the fuel properties for recycling purpose. Waste engine oil was pyrolyzed in a microwave-induced pyrolyzer at 400 °C under vacuum and the N2 was used to purge the pyrolysis zone to minimize O2. The fresh and waste engine oils were pyrolyzed and determined it by-products yield, and then the original and pyrolyzed waste engine oils were analyzed its chemical composition for their fuel properties following the standard method. The by-products fuel-related properties obtained from the only waste engine oil were comparable to those mixing oil with particulate carbon and different media of microwave and conventional electric heating reactors. In term of its feasibility application to energy and chemical industries this finding could be better with lower production cost.

Fast Pyrolysis of Oil Palm Kernel Shell in a Fluidized Bed Reactor: The Effect of Pyrolysis Temperature on the Yields of Pyrolysis Products

This study investigates the effect of pyrolysis temperature on the yields of char, organic compounds, water and gas. Fast pyrolysis was carried out in a fluidized bed reactor of 108 mm in internal diameter operated at 400, 450, 500 and 550 °C with nitrogen gas with flow rate of 25 L(NTP)/min. In specific the effect of temperature on the yields of known and unknown organics in bio-oil is discussed. For higher total organics, 500 oC was favorable. But higher phenol and acetic acid yields, 450 oC was preferable. The major organics include acetic acid, phenol and furfural. The minor ones include 2-methylphenol, 4-methylphenol, 4-methylnaphthalene, benzene, toluene and THF.

Effects of methanol-to-oil ratio, catalyst amount and reaction time on the FAME yield by in situ transesterification of rubber seeds (Hevea brasiliensis)

In this research, biodiesel is produced by in situ transesterification (direct transesterification) method from the rubber seeds using KOH as a catalyst. The influence of methanol to seeds mass ratio, duration of reaction, and catalyst loading was investigated. The result shows that, the best ratio of seeds to methanol is 1:6 (10 g seeds with 60 g methanol), 120 minutes reaction time and catalyst loading of 3.0 g. The maximum FAME yield obtain was 70 %. This findings support FAME production from the seeds of rubber tree using direct transesterifcation method from the seeds of rubber tree as an alternative to diesel fuel. Also, significant properties of biodiesel such as cloud point, density, pour point, specific gravity, and viscosity were investigated.

Biodiesel Production from Palm Oil in a Millichannel Reactor

Transesterification of palm oil with methanol using a potassium hydroxide (KOH) catalyst to form fatty acid methyl ester (FAME) commercially known as biodiesel was performed in a millichannel reactor. In this study, a transparent Teflon tubular reactor with the inner diameter of 1.59 mm at 60 °C was carried out to produce FAME. Residence time was changed by changing the tube length and flow rate. The residence time of 69 s is required to achieve more than 88% of ester content. The relationship between ester content and flow pattern was also investigated.