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Running dry reforming of methane (DRM) reaction at low-temperature is highly regarded to increase thermal efficiency. However, the process requires a robust catalyst that has a strong ability to activate both CH4 and CO2 as well as strong resistance against deactivation at the reaction conditions. Thus, this paper examines the prospect of DRM reaction at low temperature (400–600 °C) over CeO2–MgO supported Nickel (Ni/CeO2–MgO) catalysts. The catalysts were synthesized and characterized by XRD, N2 adsorption/desorption, FE-SEM, H2-TPR, and TPD-CO2 methods. The results revealed that Ni/CeO2–MgO catalysts possess suitable BET specific surface, pore volume, reducibility and basic sites, typical of heterogeneous catalysts required for DRM reaction. Remarkably, the activity of the catalysts at lower temperature reaction indicates the workability of the catalysts to activate both CH4 and CO2 at 400 °C. Increasing Ni loading and reaction temperature has gradually increased CH4 conversion. 20 wt% Ni/CeO2–MgO catalyst, CH4 conversion reached 17% at 400 °C while at 900 °C it was 97.6% with considerable stability during the time on stream. Whereas, CO2 conversions were 18.4% and 98.9% at 400 °C and 900 °C, respectively. Additionally, a higher CO2 conversion was obtained over the catalysts with 15 wt% Ni content when the temperature was higher than 600 °C. This is because of the balance between a high number of Ni active sites and high basicity. The characterization of the used catalyst by TGA, FE-SEM and Raman Spectroscopy confirmed the presence of amorphous carbon at lower temperature reaction and carbon nanotubes at higher temperature.

A catalytic transfer hydrogenation of castor oil using glycerol-based is a process of adding hydrogen to the castor oil to produce hydrogenated castor oil with the addition of 10% Pd/C as the catalyst and glycerol as a hydrogen donor. The reaction occurred at the reaction temperature of 178 °C for an hour. To prove whether glycerol can be one of the hydrogen donors like limonene that is commonly used, the research started by using pure glycerol as the hydrogen donor and as a control to determine the protocol. A direct heating apparatus connected with a reflux system was used for this experiment. The result from FTIR along with the melting point shows the formation of hydrogenated castor oil from this reaction. The increment in melting point value and the absence of C=C peak (1655.79 cm−1) from FTIR spectrum shows that the catalytic transfer hydrogenation successfully occurred. The melting point of the hydrogenated castor oil is 65 °C and the melting point of castor oil is − 7 °C. Therefore, it was proven that, the glycerol can be used as the hydrogen donor for the castor oil for a catalytic transfer hydrogenation reaction.

The catalytic and non-catalytic pyrolytic conversion kinetics of palm kernel shell (PKS) with untreated (as received) and H2SO4-treated coal bottom ash as catalyst were investigated in this study. Flynn-Wall-Ozawa (FWO) and distributed activation energy model (DAEM) isoconversional kinetic models were exploited to evaluate the kinetic parameters. The study was conducted using thermogravimetric analysis at 10, 20, 30, and 50 °C/min heating rates. The activation energy (Ea) and pre-exponential factor (A) for non-catalytic PKS decomposition for DAEM ranged from 74.39 to 217.05 kJ/mol and 4.77E+01 to 1.99E+14 s−1 at different conversions while for the untreated ash, the ranges were 103.84–402.53 kJ/mol and 7.35E+03–1.04E+29 s−1. In the decomposition with treated ash, Ea and A were 81.79–191.07 kJ/mol and 1.61E+02–1.20E+12 s−1 for 7 wt% ash and 74.41–137.35 kJ/mol and 4.91E+03–4.53E+08 s−1. Values of Ea and A obtained for FWO followed the same pattern and are in close agreement with that obtained using DAEM. The use of 10 wt% acid-treated ash reduced the activation energy compared with the non-catalytic process by about 33.05% while the untreated ash increased the activation energy. The kinetic parameters were determined satisfactorily using the first-order reaction mechanism.

Several steps are employed for the production of lignin, to ensure better extraction. Pretreatment is one of the important steps in all biochemical conversion, including biomass feedstock, using different methods such as mechanical, thermal, physicochemical, chemical, and biological. Pretreatment can affect the feedstock in terms of structure and crystallinity, lignin modification, and changes in composition. Following the pretreatment, isolation of lignin is done using a few other methods including acid, alkali, organosolv, ionic liquid, and enzymatic hydrolysis, as well as physicochemical methods with significant yield and purity. The lignin extracted from biomass can be utilized in many other industries including fuel, medical, agricultural, and carbon-based materials. There is a lack of specific applications of lignin in Malaysia despite its huge potential in several main economic sectors. Ultimately, lignin should be effectively utilized to drive the value-chain of biomass valorization.

Due to food security issues and weeds problem in rice production, allelopathy is introduced as an alternative towards sustainable weeds management. One of Myrtacea plants known as Melaleuca cajuputi extract is studied to assess its herbicidal or allelopathic effect on notorious paddy weeds known as barnyard grass. The plant extract of Melaleuca cajuputi is extracted using supercritical carbon dioxide extraction and soxhlet extraction. The chemical composition of the extract is determined using gas chromatograph mass spectrometry analysis and it was reported that caryophyllene and humulene are detected as the two major sesquiterpenes present. The effectiveness of the inhibition of the weeds was also studied and compared with conventional herbicides and caryophyllene standards. It is determined that Melaleuca cajuputi extract of supercritical and soxhlet extraction induces visible injuries towards the weeds at bud stage of less than 0.75 cm. Thus, it is recommended to increase the concentration higher than 0.05 M to suppress the weeds that grown. Melaleuca cajuputi oil can be further studied to be a potential source for bio-herbicides.

Marine and freshwater microalgae grow in two different ecosystems, which influence their properties thus requires attention prior to determining its application. This paper has successfully disclosed the thermal, chemical, and physical properties of two types of microalgae on carbon dioxide (CO2) fixation and underwent pyrolysis process. Slow pyrolysis process for marine and freshwater microalgae (Isochrysis sp. and Monoraphidium c.) was performed in the fixed bed pyrolysis reactor and TGA (thermogravimetric analyzer) to determine the product yield and study their thermal decomposition profile. The pyrolysis was completed at various temperatures (400, 450, 500, and 550°C) at a heating rate of 15 °Cmin-1 and nitrogen flow rate of 200 ml min-1. Pyrolysis in TGA analyzer ran from 27 to 800°C at three heating rates (10, 20, and 40 °Cmin-1). For chemical composition, Fourier-transform Infrared (FTIR) analysis was performed on both microalgae samples. The highest yield (up to 33.9%) of bio-oil was obtained from Isochrysis sp. for all temperatures while the highest average yield (65.78%) of bio-char was collected from Monoraphidium c. species. From TGA pyrolysis, the major decomposition occurred between 200-400°C for Monoraphidium c. species. On the other hand, the decomposition profile of Isochrysis sp. was slightly slower, which may be due to the differences in lipid composition (FTIR peak 2929 cm-1). The activation energy of all tests is lower (33.6-40.3 kJ mol-1) compared to several other biomasses. Marine species fixed with CO2 showed promising results even without addition of catalyst and no additional cost needed.

Interest in torrefaction has improved along the recent years and it has been studied extensively as a mean of preparing solid fuels. Biomass to be considered as a renewable source of energy must endeavor improvement continuously and where it is more sustainable going forward in which can come from waste product, wild and cultivated plant. The aim of this study is to investigate the effect of temperature and residence time of wild Napier grass and Oil palm petiole from waste. The torrefied samples were derived by pyrolysis reactor mimicking torrefaction procedure. The temperature parameter ranges between 220 and 300 ℃ while residence time parameter is from 10 minutes to 50 minutes of reaction. It was found that as temperature and time increasing, moisture content and amount of O and H atoms decreases as well as both mass and energy yield, but calorific value and the energy density increase along with both two parameters. Between the two parameters, the temperature variation shows more significant changes to the torrefied samples as compared time. The optimized temperature and time are found to be 260 ℃ and 30 minutes, respectively. Remarkably, the usage of pyrolyzer as torrefaction reaction has proved to be a good option since they share similar characteristics while can also produce product with similar properties reflecting torrefaction process.

Agriculture materials of oil palm tree and forestry such as rubber tree are commonly utilised and this can be contributed to the wastes. Therefore, this research is looking for value-added to these types of materials from the production of pyrolysis oil. This paper was intended to determine the best ratio of feedstock to produce high quantity of bio-oil yield and to determine properties of chemicals produced in bio-oil. The samples of empty fruit bunches (EFB) with palm kernel shell (PKS), palm leaves (PL) and sawdust (SDT) were co-pyrolyzed with different ratios (25:75, 50:50 and 75:25) to produce liquid oil, and the yield was analyzed and characterized by using GC-MS. The results show the mixture of EFB:PKS with ratio of 25:75 produced the highest yield of 40.53%, meanwhile, the co-pyrolysis of EFB:SDT produced the lowest yield which was 19.25%. The chemicals for each bio-oil were determined and the major organic chemicals such as phenols, aldehydes group, methyl alcohol and acetic acids were found for the purpose products of our fine chemicals.

Anaerobic digestion (AD) is one of the renewable technologies and a good alternative for the management of livestock manure. The present study focuses on co-digestion of fresh chicken manure (FCM) with corn stover (CS) experiments for biogas production. The objective of this study is to evaluate the effect of corn stover in the production of biogas and methane content by co-digestion. The mixing ratios of co-digestion of FCM with CS were 1:1, 1:2, and 2:1. The total solids for co-digestion were 8% for all ratios. The results showed that the ratio of 2:1 produced the highest biogas yield (46.7 m3/ton of slurry) and 53.2% of methane purity. The pH fluctuated around a range of 5.2 to 7.9 due to different stages of anaerobic digestion as a result of microbe’s activity.

Dry reforming of methane (DRM) is becoming an appealing research topic because of the urgent need to minimize global warming and the demand for alternative energy resources. However, DRM commercialization and industrial scale application are limited by the deactivation of the applied catalysts. In this work, Ni-based catalysts supported on CeO2–MgO mixed oxides (0–20% CeO2 molar content) were prepared and employed in DRM. The support was synthesized via a coprecipitation method followed by impregnation of Ni metal. The catalysts prepared were characterized by X-ray diffraction, Brunauer–Emmett–Teller (BET) analysis, temperature-programmed reduction, X-ray photoelectron spectroscopy, and field emission scanning electron microscopy (FESEM) techniques. The catalytic performance of the catalysts was evaluated in a fixed-bed continuous reactor with an equimolar (CH4/CO2) ratio at 1073 K. The addition of CeO2, as a promoter to the support, altered the interaction between Ni and MgO and modulated the properties ...

The brown planthopper (BPH) causes serious damage to rice by sucking rice sap, ovipositing in rice tissues, and transmitting a number of rice diseases during its long-distance migration that severely affect the productivity of paddy. Thus, the aim of this study is to investigate the effectiveness of biopesticides against BPH population. BV500WS is used at the early stage of paddy cultivation for growth enhancement meanwhile BV612EC is used a week after the liberation of BPH for crop protection. Three conditions were adopted as follows which are T1 where the paddy was sprayed using BV500WS and BV612EC to study the effectiveness of both types of biopesticides, T2 where the paddy was sprayed using BV500WS only and C1 where the paddy was cultivated without any pesticide application as control. BPH was released twice on day 46 and 59 of paddy cultivation. Reduction of BPH population with up to 100% mortality rate was observed with the application of two types of biopesticides at T1 resulting in the highest number of remaining tillers with 68.56%. Although severely affected by BPH, T2 was able to has comparable number of remaining tillers as C1 which was 46.24% and 49.65% respectively. These results showed that two types of biopesticides were more effective in reducing BPH compared to one type of biopesticide.

There is an urgent need to enhance the productivity of irrigated paddy fields to increase the rice production that meets population growth. The focus of this study is to investigate the effectiveness of biopesticides in enhancing the paddy growth for yield improvement after controlling the pest and rice diseases. This study aims to determine either one or two types of biopesticides should be used in paddy cultivation. Thus, three conditions were adopted in paddy cultivation at the insect house as follows; T1 where the paddy was sprayed using BV500WS and BV612EC to study the effectiveness of the biopesticides, T2 where the paddy was sprayed using BV500WS only and C1 where the paddy was cultivated following the conventional technique as a control. BV500WS was sprayed into T1 and T2 on the first day of paddy growth while BV612EC was sprayed later into T1, at 55 and 67 days of paddy cultivation a week after releasing the brown planthopper (BPH). Based on the analysis of correlation obtained for each growth, application of BV500WS and BV612EC of T1 resulted in better performance in terms of height of plant, number of tillers, width of leaves, and number of leaves compared to T2 and C1. The excellence performance of plant growth at T1 produced the highest paddy yield of 2304.20 ± 491.42 g−2, while T2 produced comparable yield as C1 which are 663.88 ± 128.41 g−2 and 665.42 ± 183.30 g−2 respectively. Hence, organic plants based biopesticides are successful in enhancing the plant growth of paddy and ultimately increase the paddy yield.

Due to the rice production problem, control of paddy weeds with the use of allelopathy as active compounds serve as new alternative for sustainable weeds management. The volatile oil from Melaleuca cajuputi which has possible active allelopathy compound present is extracted and analyzed. Response Surface Methodology (RSM) with central composite rotatable design (CCRD) is used to design the experiment for optimization of supercritical carbon dioxide (SC-CO2) extraction of volatile oil from Melaleuca cajuputi leaves for maximum oil yield. Three factors which included carbon dioxide (CO2) flow rate (4–7 ml/min), temperature (40–55 ℃ ) and pressure (14–26 MPa) were investigated. The regression model shows a good prediction with coefficient of determination, R2 of 0.9607. The optimum condition of SC-CO2 extraction is determined to be at CO2 flow rate of 5.88 ml/min, temperature of 43.10 ℃ and pressure of 24.91 MPa with the prediction yield of 1.24 wt%. The optimum condition is validated with experimental runs which gives an average yield of 1.26 wt% which indicates good agreement between the measured and predicted value. The chemical composition of the volatile oil at optimized condition is analyzed using Gas Chromatography Mass Spectrometry (GC–MS) and Gas Chromatography with Flame Ionization Detector (GC-FID). Caryophyllene and humulene are the two major sesquiterpenes detected from the optimized condition. Thus, volatile oil extract from the foliage of Melaleuca cajuputi can be considered as potential source for bio-herbicides due to the presence of caryophyllene which has allelopathic effect. Kinetics studies are also studied with modified Reverchon-Sesti Osseo as the model fitting.

Microalgae technology can play important roles in wastewater management, carbon dioxide fixation and as biofuels feedstock if managed properly. The core challenge is to substantially lower the cultivation and harvesting costs. This study assesses performances of batch wise photobioreactor (PBR) and sequencing batch membrane photobioreactor (SB-MPBR) for polishing real secondary effluent, and at the same time producing lipid by cultivating a native strain of Euglena sp. Lab-scale data were used to project large-scale performance of an SB-MPBR and its economic potential was compared with established conventional biological nutrients removal technologies. Results show that the SB-MPBR with 4 days retention was found to be optimum in terms of nutrients removal (≥95% and ≥70% respectively for total nitrogen and total phosphorous), water treatment capacity and lipid yield (≥10%). However, an energy audit on the process shows that the chemical energy from the produced lipid is still at least 111 fold short of meeting an energy neutral process. However, results of preliminary cost analysis indicate that SB-MPBR (0.113 $/m 3 ) is highly attractive technology for biological nutrients removal than the conventional technologies (0.65–0.96 $/m 3 ).

Rubber seed oil (RSO) is a well-known non-edible oil currently not commercially used because no major application has been identified. Recently, studies of biodiesel produced from RSO have been reported. However, RSO biodiesel production potential and fossil diesel substitution potential have not been clarified. We report here estimates of the biodiesel production potential from rubber seed in natural-rubber-producing countries, with a combination of statistical data and original experimental data. The result shows that Indonesia has a RSO production potential of 889 098 tons/year as the highest country. In Nigeria, 15.1% of current fossil diesel consumption can potentially be replaced by biodiesel produced from an annual output of RSO locally. The usage of RSO for producing biodiesel is one option of reducing the biodiesel production dependency upon edible oil in these countries. The development of biodiesel production using RSO could play an important role in the natural-rubber-producing countries, such...

The outlook and incentive toward the development of cleaner and sustainable energy resources are growing worldwide due to the rise of fossil fuel price, depletion of petroleum resources, and environmental protection issues. Therefore, the development of biofuel technologies, that is, bio-based fuels are projected to play an essential role in the foreseeable transportation and automotive industries. Synthetic biofuels from agricultural-based origins such as biohydrogen, biogas, biogasoline, biodiesel, and green diesel will emerge as prospective fuels of tomorrow due to their excellent fuel properties and environmental friendly attributes. Thus, this book chapter focuses on the challenges and drawbacks of the existing liquid and gaseous biofuel production technologies. To overcome these challenges, advanced biofuel technologies such as steam gasification, ultrasonic and microwave intensification for biodiesel production, catalytic cracking and hydrodeoxygenation of vegetable oils for biogasoline, and green diesel have been discussed in detailed. Furthermore, critical analysis on the fundamental reaction and process optimization affecting the biofuel production has been conversed as well. This chapter also addresses the future prospective of emerging biofuel technologies that could potentially bridge with the existing biofuels technologies.

Transesterification of castor oil, sunflower oil and mixture of both oils were conducted in a millichannel reactor with 1.6 mm internal diameter. The flow behavior of the sample in millichannel reactor was observed. Both of the oil was mixed from 100 mL of castor oil until 20 mL of castor oil with total amount of 100 mL solution before used in the reaction. The alkali catalyst was mixed together with methanol before entering the reactor. In this study, the behavior of the flow pattern inside the millichannel reactor was observed under fixed parameters which are 21:1 methanol-to-oil molar ratio, 5.4 wt% of KOH concentration in methanol, 180 s of residence time and 60 C of temperature. The FFA value of both the oils was less than 2 mg-KOH/g-oil. The viscosity and density of the oils were determined before and after mixing the oils. The flow behaviour of the castor oil formed parallel flow throughout the reactor while sunflower oil formed slug flow in the reactor. When the volume of castor oil is reduced from 100 mL to 20 mL, the flow behaviours of the mixture oil were changed from slug flow at upstream to parallel flow at downstream. The formation of slug flow in the reactor improved the biodiesel yield: 88.4% of FAME yield.

In this research, rubber wood sawdust (RWS) and Meranti wood sawdust (MWS) were 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, 550, 600, 650 °C) on the yield of pyrolysis products. Pyrolysis of these different residues generate an almost identical maximum amount of bio-oil close to 33 wt.%, but at different maximum temperature (550 °C for pyrolysis of RWS and 600 °C for pyrolysis of MWS). To evaluate the effect of biomass type on the composition and characterization of pyrolysis products, the second part involves the analyses of pyrolysis products from the maximum pyrolysis temperature. Acetic acid, tetrahydrofuran, and benzene were the main bio-oil components. The bio-oil contained high percentage of oxygen and hydrogen, indicating high water content in the bio-oil. High amount of water in bio-oil significantly reduced its calorific value. Under extensive heating, particle size of the bio-char from SEM images decreased due to breakage and shrinkage mechanisms. The major components of non-condensable gases were CO and CO2.

Bio-char is a carbon-rich solid material generated by thermochemical conversion process (pyrolysis) of lignocellulosic biomass, and its viability as a sustainable material has received increasing attention for environmental remediation. The relationship between bio-char properties and its applicability as a soil amendment is still not conclusive. The purpose of this research is to study the bio-char physical and chemical properties from an agricultural residue to examine the quality criteria for carbon sequestration and agricultural uses. Pyrolysis temperature was shown to have a strong impact on production and characteristics of bio-char samples. The bio-char yield decreased with increasing temperatures (350–550 °C). According to proximate and ultimate analysis data, temperature has the strongest impact on carbon stability of bio-char (stability increased at higher temperature). The volatile matter decreased while fixed carbon content increased with the increase of pyrolysis temperature. To evaluate further bio-char quality, the relationships between (O/C and H/C molar ratio) and (H/C and volatile matter) of raw paddy husk and produced bio-char at various temperatures is proposed. SEM, FT-IR, and 13C NMR findings are in well agreement with thermogravimetric and proximate analysis of the bio-char that structural and physicochemical properties were significantly influenced by pyrolysis temperature. CO2 adsorption rate increased with increasing temperature. Bio-char produced at 450 °C showed higher absorption capability and could be a potential sustainable substrate for C sequestration and soil amendment.

Torrefaction of oil palm kernel shell (PKS), one of the biomass residues from the palm oil industry, was carried out in a fixed-bed tubular reactor in the presence of oxygen and carbon dioxide at concentrations ranging from 0 to 15 vol.% (nitrogen balance). The effects of oxygen and carbon dioxide concentrations (0, 3, 9, 12, and 15 vol.%), temperature (493, 523, and 573 K) and biomass size (0.375 mm and unground) on the solid phase conversion, the energy yield and properties of torrefied biomass were investigated. The solid phase conversion increased with increasing temperature and oxygen or carbon dioxide concentration, but was not significantly affected by biomass size. The energy yield decreased with increasing oxygen or carbon dioxide concentration, but was still more than 70%. The extent of torrefaction was in the order of oxygen > carbon dioxide > nitrogen. The ‘oxidative torrefaction’ rate was extracted from the overall reaction rate. The increase in the oxidative torrefaction rate caused by oxygen was higher than that caused by carbon dioxide. Scanning electron microscope observations of the morphology of the PKS showed distinctive differences for torrefaction in nitrogen, oxygen, and carbon dioxide.

Thermogravimetric data, the Coats–Redfern free integral method, and correlation coefficients obtained by use of different reaction models were used to study the kinetic characteristics of non-catalytic and catalytic pyrolysis of biomass. Zeolite catalysts (ZSM-5, MCM-22, and ITQ-2) were mixed with the biomass in the ratio 1:10. Analysis of thermogravimetric data revealed that thermal decomposition occurred at 240–450 °C for both non-catalytic and catalytic pyrolysis of biomass. Two temperature regions, region I 240–330 °C and region II 360–450 °C, were identified and a best-fit model describing the behavior of non-catalytic and catalytic biomass pyrolysis was obtained. Addition of catalyst reduces the activation energy in first region then increases it in the second region for all reaction orders. Chemical reaction and diffusion-controlled reaction mechanisms could be kinetically characterized and enabled good description of the nature of biomass pyrolysis.

A catalytic transfer hydrogenation of castor oil using glycerol-based is a process of adding hydrogen to the castor oil to produce hydrogenated castor oil with the addition of 10% Pd/C as the catalyst and glycerol as a hydrogen donor. The reaction occurred at the reaction temperature of 178°C for an hour. To prove whether glycerol can be one of the hydrogen donors like limonene that is commonly used, the research started by using pure glycerol as the hydrogen donor and as a control to determine the protocol. A direct heating aparatus connected with a reflux system was used for this experiment. The result from FTIR along with the melting point shows the formation of hydrogenated castor oil from this reaction. The increment in melting point value and the absence of C=C peak (1655.79 cm−1) from FTIR spectrum shows that the catalytic transfer hydrogenation successfully occurred. The melting point of the hydrogenated castor oil is 65°C and the melting point of castor oil is -7°C. Therefore, it was proven that, the glycerol can be used as the hydrogen donor for the castor oil for a catalytic transfer hydrogenation reaction.

International audience; AbstractKey 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.

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.

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.

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.

Microalgae technology is attractive for simultaneously treating wastewater and producing valuable biomass. However, biofuel application demands a very low net-energy input that can hardly be fulfilled. Therefore, exploration of a more direct-use of microalgae biomass and selection of appropriate microalgae species are necessary to fine-tune viable applications. This study assesses performance of sequencing batch membrane photobioreactors (SB-MPBRs) for simultaneously polishing secondary effluent by cultivating Staurastrum sp., a species suitable as aquaculture feed. The effect of feed composition (high and low phosphorous, P) on microalgae growth, membrane fouling propensity, nutrient removal, as well as oxygen enrichment capacity were evaluated. Overall results demonstrate the effectiveness of SB-MPBR to cultivate Staurastrum sp. in secondary effluent by achieving biomass concentration of 0.45 and 0.6 g/L and very low nutrients concentrations in the effluents (≈ 0, 10 and 2 mg/L, for chemical oxygen demand (COD), TN and TP respectively). The actual biomass productivity of the SM-MPBRS are 40.0 and 30.0 g/(day m3) for the low-P and high-P feeds, corresponding to production costs of 11.3 and 15.1 $/kg biomass, respectively. Low-P feed results in a slightly higher biomass productivity of 33% compare to high-P feed, but slightly higher fouling propensity. The growth in both SB-MPBRS seems to be limited by the inorganic carbon supply. Too-short HRT leads to nutrients accumulation of the nutrients and eventually reduced their removal efficiencies. Overall results show a new cultivation method for aquaculture feed while at the same time polish secondary effluent and enrich its oxygen concentration.

Application of microtube reactor for the continuous synthesis of biodiesel has been widely studied due to excellent performance in liquid-liquid phase reaction. In order to commercialize biodiesel production, integration of microtube reactor is highly recommended. Therefore, in this study, synthesis of biodiesel was carried out in capillary millichannel reactor with inner diameter of 1.59 mm using methanol and potassium hydroxide (KOH) as base catalyst with palm oil as a feedstock. The influences of reaction temperature, methanol to oil molar ratio, and KOH concentration on the production of fatty acid methyl ester (FAME) were examined. The highest FAME yield was achieved at 60 ˚C with 23:1 methanol to oil molar ratio and 5 wt% of KOH concentration.

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.

Thermal modification of wood constituents occurs upon hot-pressing of flakes during consolidation of oriented strand board (OSB). Hence, the effects of hot-pressing of hybrid poplar on water-soluble extractives were studied. Poplar veneers were pre-conditioned to 0 or 8 % moisture content and subsequently hot-pressed at 150, 200 or 250 °C. Aqueous extracts were characterized by conventional chemical methods in conjunction with chromatography (HPLC and SEC), mass spectrometry (ESI–MS) and spectroscopy (FTIR) analysis. Water-soluble fractions were markedly influenced by thermal compression treatment at 250 °C compared to the lower temperatures. Chromatographic results indicate that water-soluble extractives content increases with temperature while the degree of polymerization decreases with detection at low temperature levels. FTIR spectroscopic analysis indicates changes in aqueous-extracts composition of wood monosaccharides (hemicelluloses), meanwhile ESI–MS detected xylo-oligosaccharides. These results clearly show that heat treatment dictated the changes in each water-soluble extractive component and they respond independently with different treatment.

Oil palm empty fruit bunch (OPEFB) fiber is a natural polymer which is potentially used as efficient adsorbents for heavy metal cations. The main objective of this research is to synthesize OPEFB grafted polyvinyl alcohol (PVA) hydrogel by using ammonium persulfate (APS) as initiator and gelatin as crosslinking agent. The grafting temperature, amounts of cross linking agent, initiator and concentration of OPEFB were manipulated in order to optimize the swelling capability of the hydrogel. Comparison of heavy metal adsorption performance between pure PVA hydrogel and optimized OPEFB-g-PVA hydrogel was evaluated by using copper ions solution. The characteristics and structure of the optimized OPEFB-g-PVA hydrogel was studied by using Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM) while Thermogravimetric Analysis (TGA) was used to study its thermal stability. The presence of band at 1088 and 1047cm-1 corresponds to C-O was observed as strong evidence of grafting. Water ...

This paper investigates the effect of sulfuric acid (H2SO4) concentration, as an additive to enhance the production of anhydrosugars via pyrolysis of Douglas-fir, on the yield and composition of the lignin derived oligomers. Pyrolysis tests at 500 °C were conducted in auger and fluidized bed reactors. For both reactors the yield of lignin derived oligomers decreased as H2SO4 was added. Several analytical techniques (UV-fluorescence, TGA, ESI-MS, FTIR, solid state 13C NMR and Pyrolysis-GC/MS) were used to characterize the lignin derived oligomers collected. Four peaks were observed in the UV-fluorescence spectra. The addition of H2SO4 reduces the yield of all the peaks. DTG curves also show the presence of several peaks. The addition of H2SO4 decreased the yield of all the peaks but its effect was more pronounced on peaks at 320 and 400 °C. Electrospray ionization-mass spectrometry studies did not show any major change on the molecular weight of the lignin oligomers ionized products obtained as a function of H2SO4 concentration. Solid state NMR results indicate that the methoxyl groups decreased and the carbonyl increased gradually as sulfuric acid concentration increases. The Py-GC/MS confirmed the phenolic compounds with methoxyl substitutions were substantially reduced as the acid concentration increased. The experimental results obtained suggest the presence of H2SO4 enhances the polycondensation of methoxyl substituted aromatic rings.

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.

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.

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.

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.

Oil palm empty fruit bunches activated carbon of different parts (shaggy and core) were characterized as to convert waste of oil palm-based into value added products. Conventional step processes of physical activation were performed where activation was undertaken after the pyrolysis process (carbonization-activation process). The pyrolysis temperatures applied were 400, 450, and 500°C in inert condition under nitrogen flow. For the activation process, 600, 700, and 800°C with the presence of 15%, 60%, and 100% CO 2 and holding time of 30, 60, and 120 minutes were applied. Results showed that activation temperature, CO 2 percentage and holding time did dictate the changes of activated carbon yield, carbon content, and textural properties of the activated carbon core and shaggy EFB produces. The highest yield of activated carbon was obtained from 700°C (middle temperature), 60% CO 2 (middle percentage), and 30 mins holding time (shortest). However, the highest carbon content was detected from 600°C, 60% CO2, and 60 mins of activated carbon core EFB. The size of pore determined prove that the three parameter do not correlate with each other as the bigger pore diameter was derived from 700°C, 60% of CO 2 , and 60 mins holding time. Hence, the results revealed that there are differences of activated carbon properties when we separate EFB part into its core and shaggy.