Showing papers in "Energy & Fuels in 2006"

Pyrolysis of Wood/Biomass for Bio-oil: A Critical Review

Abstract: Fast pyrolysis utilizes biomass to produce a product that is used both as an energy source and a feedstock for chemical production. Considerable efforts have been made to convert wood biomass to liquid fuels and chemicals since the oil crisis in mid-1970s. This review focuses on the recent developments in the wood pyrolysis and reports the characteristics of the resulting bio-oils, which are the main products of fast wood pyrolysis. Virtually any form of biomass can be considered for fast pyrolysis. Most work has been performed on wood, because of its consistency and comparability between tests. However, nearly 100 types of biomass have been tested, ranging from agricultural wastes such as straw, olive pits, and nut shells to energy crops such as miscanthus and sorghum. Forestry wastes such as bark and thinnings and other solid wastes, including sewage sludge and leather wastes, have also been studied. In this review, the main (although not exclusive) emphasis has been given to wood. The literature on woo...

In-depth investigation of biomass pyrolysis based on three major components: Hemicellulose, cellulose and lignin

Abstract: To better understand biomass pyrolysis, the different roles of the three components (hemicellulose, cellulose, and lignin) in pyrolysis are investigated in depth using a thermogravimetric analyzer (TGA). The pyrolysis characteristics of the three components are first analyzed, and the process of biomass pyrolysis is divided into four ranges according to the temperatures specified by individual components. Second, synthesized biomass samples containing two or three of the biomass components are developed on the basis of a simplex-lattice approach. The pyrolysis of the synthesized samples indicates negligible interaction among the three components and a linear relationship occurring between the weight loss and proportion of hemicellulose (or cellulose) and residues at the specified temperature ranges. Finally, two sets of multiple linear-regression equations are established for predicting the component proportions in a biomass and the weight loss of a biomass during pyrolysis in TGA, respectively. The resul...

History of the Development of Low Dosage Hydrate Inhibitors

Abstract: Low dosage hydrate inhibitors (LDHIs) are a recent and alternative technology to thermodynamic inhibitors for preventing gas hydrates from plugging oil and gas production wells and pipelines. LDHIs are divided into two main categories, kinetic inhibitors (KHIs) and anti-agglomerants (AAs), both of which are successfully being used in field applications. This paper reviews the research and development of LDHIs with emphasis on the chemical structures that have been designed and tested. The mechanisms of both KHIs and AAs are also discussed.

Biorefineries: Current Status, Challenges, and Future Direction

Abstract: Conventional resources mainly fossil fuels are becoming limited because of the rapid increase in energy demand. This imbalance in energy demand and supply has placed immense pressure not only on consumer prices but also on the environment, prompting mankind to look for sustainable energy resources. Biomass is one such environmentally friendly renewable resource from which various useful chemicals and fuels can be produced. A system similar to a petroleum refinery is required to produce fuels and useful chemicals from biomass and is known as a biorefinery. Biorefineries have been categorized in three phases based on the flexibility of input, processing capabilities, and product generation. Phase I has less or no flexibility in any of the three aforementioned categories. Phase II, while having fixed input and processing capabilities, allows flexibility in product generation. Phase III allows flexibility in all the three processes and is based on the concept of high-value low-volume (HVLV) and low-value high...

Exhaust Emissions of Biodiesel, Petrodiesel, Neat Methyl Esters, and Alkanes in a New Technology Engine†

Abstract: Biodiesel is a renewable, alternative diesel fuel of domestic origin derived from a variety of fats and oils by a transesterification reaction; thus, it consists of the alkyl esters, usually methyl esters, of the fatty acids of the parent oil or fat. An advantage of biodiesel is its potential to significantly reduce most regulated exhaust emissions, including particulate matter (PM), with the exception of nitrogen oxides (NOx). In this work, three fatty acid methyl esters, neat methyl laurate, neat methyl palmitate, and technical grade methyl oleate, were selected for exhaust emissions testing in a heavy-duty 2003 six-cylinder 14 L diesel engine with exhaust gas recirculation. These fuels were compared with neat dodecane and hexadecane as well as commercial samples of biodiesel and low-sulfur petrodiesel as the base fuel, thus establishing for the first time a baseline of the exhaust emissions of neat hydrocarbon (alkane) fuels versus neat methyl esters. All fuels were tested over the heavy-duty diesel tr...

Thermal and Chemical Stability of Regenerable Solid Amine Sorbent for CO2 Capture

Abstract: The adsorption and desorption of CO2 and SO2 on an amine-grafted SBA-15 sorbent has been studied by in situ infrared spectroscopy coupled with mass spectrometry. CO2 adsorbed on an amine-grafted sorbent as carbonates and bicarbonates, while SO2 adsorbed as sulfates and sulfites. The CO2 adsorption capacity of the amine-grafted sorbent was almost twice as much as that of a commercial sorbent. The adsorption of CO2 in the presence of H2O and D2O shows an isotopic shift in the IR frequency of adsorbed carbonate and bicarbonate bands, revealing that water plays a role in the CO2 adsorption on amine-grafted sorbents. Although the rate of adsorption of SO2 was slower than that of CO2, the adsorbed S surface species is capable of blocking the active amine sites for CO2 adsorption. A temperature-programmed degradation study of the amine-grafted sorbent showed that the surface amine species are stable up to 250 °C in air.

Room-Temperature Conversion of Soybean Oil and Poultry Fat to Biodiesel Catalyzed by Nanocrystalline Calcium Oxides

Abstract: A promising route for the production of biodiesel (fatty acid methyl esters, FAMES) via transesterification of soybean oil (SBO) and poultry fat with methanol in quantitative conversions at room temperature has been developed using nanocrystalline calcium oxides as catalysts. Under the same conditions, laboratory-grade CaO gave only 2% conversion in the case of SBO, and there was no observable reaction with poultry fat. The soybean oil/methanol ratio in our protocol is 1:27. With our most active catalyst, deactivation was observed after eight cycles with SBO and after three cycles with poultry fat. Deactivation may be associated with one or more of the following factors: the presence of organic impurities or adventitious moisture and enolate formation by the deprotonation of the carbon alpha to the carboxy group in the triglyceride or FAMES. The biodiesel from our protocol meets the ASTM D-874 standard for sulfated ash for both substrates.

NOx Reduction from Biodiesel Fuels

Abstract: The demand for energy around the world is increasing, specifically the demand for petroleum-based energy. Appeasing this growing energy demand without irreparably damaging the environment is of primary concern. With rising fuel prices and environmental concerns, alternative fuels could satisfy the need for renewable energy with low environmental impact. Some of the more popular alternative fuels for new vehicles are ethanol, hydrogen, and biodiesel. Although gasoline engines are expected to be replaced by hydrogen-powered fuel cells, compression-ignition engines, the diesel engines, are expected to remain in use for high-power applications because of limitations of hydrogen-storage densities. The viable environmental friendly alternative fuel for compression-ignition engines is methyl esters (commonly known as biodiesel), which is derived from vegetable oils or animal fats. Using biodiesel instead of conventional diesel fuel reduces emissions such as the overall life cycle of carbon dioxide (CO2), particu...

Extractive Desulfurization of Gasoline Using Imidazolium-Based Phosphoric Ionic Liquids

Abstract: Sulfur partition coefficients for sulfur compounds 3-methylthiophene (3-MT), benzothiophene (BT), and dibenzothiophene (DBT) between phosphoric ionic liquids (ILs), namely, N-methyl-N-methylimidazolium dimethyl phosphate ([MMIM][DMP]), N-ethyl-N-methylimidazolium diethyl phosphate ([EMIM][DEP]), and N-butyl-N-methylimidazolium dibutyl phosphate (BMIM][DBP]), and gasoline were determined experimentally at 298.15 K over a wide range of sulfur content and compared with other IL extractants. The solubility of sulfur (as DBT, BT) in ILs aqueous solution at 298.15 K and varying water content was also measured. It was shown that the desulfurization ability of the ILs for each sulfur component (DBT, BT, 3-MT) followed the order of [BMIM][DBP] > [EMIM][DEP] ≫ [MMIM][DMP], and the sulfur removal selectivity for a specified IL followed the order of DBT > BT > 3-MT. The phosphoric ILs are insoluble in gasoline while the fuel solubility in ILs is noticeable and follows the order of [BMIM][DBP] ≫ [EMIM][DEP] > [MMIM][D...

Investigation of chemical looping combustion by solid fuels. 1. Process analysis

Abstract: To concentrate CO2 in combustion processes by efficient and energy-saving ways is a first and very important step for its sequestration. Chemical looping combustion (CLC) could easily achieve this goal. However, only limited references are available that use coal as the energy resource in a CLC process even though the development of CLC of solid fuels follows the trend of energy utilization. This paper is the first in a series of two, where we present the concept of a CLC process of solid fuels using a circulating fluidized bed with three loop seals. The riser of this circulating fluidized bed was used as the oxidizer of the oxygen carrier; one of the loop seals was used as the reducer of the oxygen carrier and the separator for ash and oxygen carrier, and the other two loop seals were used for pressure balance in the solid recycle process. Pressure profiles of recycled solids using this process are presented in detail. For the development of an oxygen carrier, we focused on the establishment of a theoret...

Wettability Alteration and Improved Oil Recovery in Chalk: The Effect of Calcium in the Presence of Sulfate

Abstract: It was previously documented that seawater was able to change the wettability of oil-saturated chalk toward more water-wet conditions and that enhanced spontaneous imbibition of water was observed. The efficiency of the imbibition process was improved by increasing the sulfate concentration in seawater. Both calcium and sulfate present in seawater are potential determining ions toward the chalk surface; it is therefore expected that both of the ions are involved in the wettability modifying process, and the symbiotic effects between the ions are studied in this paper with the aim of improving oil recovery from moderate water-wet chalk. Outcrop chalk samples were aged at 90 °C in an acidic crude oil for at least 4 weeks. The concentration of Ca2+ was varied both in the imbibing seawater and in the initial brine. Chromatographic wettability tests showed that the initial wetting condition of the chalk was not significantly affected by changing the concentration of Ca2+ in the initial brine. Increased oil rec...

Continuous Production of Biodiesel via Transesterification from Vegetable Oils in Supercritical Methanol

Abstract: The continuous production of biodiesel (fatty acid methyl esters) by the transesterification reaction of coconut oil and palm kernel oil was studied in supercritical methanol without using any catalyst. Experiments were carried out in a tubular flow reactor, and reactions were studied at 270, 300, and 350 °C at a pressure of 10 and 19 MPa with various molar ratios of methanol-to-oils from 6 to 42. It was found that the best condition to produce methyl esters from coconut oil and palm kernel oil was at a reaction temperature of 350 °C, molar ratio of methanol-to-vegetable oil of 42, and space time 400 s. The % methyl ester conversions were 95 and 96 wt % for coconut oil and palm kernel oil, respectively. The regression models by the least-squares method were adequate to predict % methyl ester conversion with temperature, molar ratio of methanol-to-oil, and space time as the main effects. The produced methyl ester fuel properties met the specification of the ASTM biodiesel standards.

Effects of Crystallinity on Dilute Acid Hydrolysis of Cellulose by Cellulose Ball-Milling Study

Abstract: The dilute acid (0.05 M H2SO4) hydrolysis at 175 °C of samples comprised of varying fractions of crystalline (α-form) and amorphous cellulose was studied. The amorphous content, based on XRD and CP/MAS NMR, and the product (glucose) yield, based on HPLC, increased by as much as a factor of 3 upon ball milling. These results are interpreted in terms of a model involving mechanical disruption of crystallinity by breaking hydrogen bonds in α-cellulose, opening up the structure, and making more β-1,4 glycosidic bonds readily accessible to the dilute acid. However, in parallel with hydrolysis to form liquid-phase products, there are reactions of amorphous cellulose that form solid degradation products.

High-Pressure Adsorption of Methane and Carbon Dioxide on Coal

Abstract: Adsorption isotherms of methane and carbon dioxide on two kinds of Australian coals have been measured at three temperatures up to pressures of 20 MPa. The adsorption behavior is described by three isotherm equations: extended three-parameter, Langmuir, and Toth. Among these, the Toth equation is found to be the most suitable, yielding the most realistic values of pore volume of the coals and the adsorbed phase density. Also, the surface area of coals obtained from CO2 adsorption at 273 K is found to be the meaningful parameter which captures the CO2 adsorption capacity. A maximum in the excess amount adsorbed of each gas appears at a lower pressure with a decrease in temperature. For carbon dioxide, after the appearance of the maximum, an inflection point in the excess amount adsorbed is observed close to the critical density at each temperature, indicating that the decrease in the gas-phase density change with pressure influences the behavior of the excess amount adsorbed. In the context of CO2 sequest...

Redox investigation of some oxides of transition state metals Ni, Cu, Fe and Mn supported on SiO2 and MgAl2O4,

Abstract: Chemical-looping combustion (CLC) and chemical-looping reforming (CLR) involve the use of a metal oxide as an oxygen carrier which transfers oxygen from combustion air to the fuel. Two interconnected fluidized beds, a fuel reactor, and an air reactor are used in both processes. In the fuel reactor, the fuel is oxidized by a metal oxide, and in the air reactor, the reduced metal is oxidized back to the original phase. In CLC, a high conversion of the fuel to CO2 and H2O is required in the fuel reactor, whereas only a partial oxidation of the fuel is desired in CLR. Oxides of Ni, Cu, Fe, and Mn supported on SiO2 and MgAl2O4 were prepared by dry impregnation and investigated under alternating reducing and oxidizing conditions in a thermogravimetric analyzer at 800−1000 °C using fuel (10% CH4, 10% H2O, and 5% CO2) and oxidizing gas (5% O2). NiO and CuO supported on both SiO2 and MgAl2O4 showed very high reactivity. However, the reactivity of NiO/SiO2 decreased as a function of the cycle number at 950 °C but w...

Upgrading Bio-oil over Different Solid Catalysts

Abstract: Solid acid 40SiO2/TiO2−SO42- and solid base 30K2CO3/Al2O3−NaOH were prepared and compared with catalytic esterification activity according to the model reaction. Upgrading bio-oil by solid acid and solid base catalysts in the conditioned experiment was investigated, in which dynamic viscosities of bio-oil was lowered markedly, although 8 months of aging did not show much viscosity to improve its fluidity and enhance its stability positively. Even the dehydration by 3A molecular sieve still kept the fluidity well. The density of upgraded bio-oil was reduced from 1.24 to 0.96 kg/m3, and the gross calorific value increased by 50.7 and 51.8%, respectively. The acidity of upgraded bio-oil was alleviated by the solid base catalyst but intensified by the solid acid catalyst for its strong acidification. The results of gas chromatography−mass spectrometry analysis showed that the ester reaction in the bio-oil was promoted by both solid acid and solid base catalysts and that the solid acid catalyst converted volat...

Effect of Pressure on the Behavior of Copper-, Iron-, and Nickel-Based Oxygen Carriers for Chemical-Looping Combustion

Abstract: The combustion process integrated by coal gasification and chemical-looping combustion (CLC) could be used in power plants with a low energy penalty for CO2 capture. This work analyzes the main characteristics related to the CLC process necessary to use the syngas obtained in an integrated gasification combined cycle (IGCC) power plant. The kinetics of reduction with H2 and CO and oxidation with O2 of three high-reactivity oxygen carriers used in the CLC system have been determined in a thermogravimetric analyzer at atmospheric pressure. The iron- and nickel-based oxygen carriers were prepared by freeze-granulation, and the copper-based oxygen carrier was prepared by impregnation. The changing grain size model (CGSM) was used for the kinetic determination, assuming spherical grains for the freeze-granulated particles containing iron and nickel and a platelike geometry for the reacting surface of the copper-based impregnated particles. The dependence of the reaction rates on temperature was low, with the a...

Methane/CO2 Sorption Modeling for Coalbed Methane Production and CO2 Sequestration

Abstract: A thorough study of the sorption behavior of coals to methane and carbon dioxide (CO2) is critical for carbon sequestration in coal seams and enhanced coalbed methane recovery. This paper discusses the results of an ad/de-sorption study of methane and CO2, in single gas environment, on a set of coal samples taken from the San Juan and Illinois Basins. The results indicate that, under similar temperature and pressure conditions, coals exhibit higher affinity to CO2 as compared to methane and that the preferential sorption ratio varies between 2:1 and 4:1. Furthermore, the experimental data were modeled using Langmuir, BET, and Dubinin−Polanyi equations. The accuracy of the models in quantifying coal−gas sorption was compared using an error analysis technique. The Dubinin−Radushkevich equation failed to model the coal−gas sorption behavior satisfactorily. For methane, Langmuir, BET, and Dubinin-Astakhov (D-A) equations all performed satisfactorily within comparable accuracy. However, for CO2, the performanc...

Removal of Carbon Dioxide from Natural Gas by Vacuum Pressure Swing Adsorption

Abstract: A vacuum pressure swing adsorption (VSA-PSA) process is studied for the removal of carbon dioxide in a contaminated stream of natural gas to achieve fuel grade methane. The adsorbent used was zeolite 13X (CECA) where CO2 is strongly adsorbed. A Skarstrom-type cycle comprising pressurization with product, feed, countercurrent blowdown, and countercurrent purge was employed. A mixture having 60% CH4/20% CO2/20% N2 was used, and two different temperatures were evaluated in a single-column VSA-PSA unit. Under the conditions tested, CO2 was removed to levels lower than 2% as required by fuel grade methane with methane recovery higher than 80% without recycle. This separation process also helps in the CH4−N2 separation. A bidisperse (macropore−micropore) model also including distributed energy balances in gas, solid, and column wall considering heat and mass transfer resistance at the gas−solid interface was used to simulate the VSA-PSA behavior and compare with experiments. Also, some scale-up considerations a...

Release to the Gas Phase of Inorganic Elements during Wood Combustion. Part 1: Development and Evaluation of Quantification Methods

Abstract: During wood combustion, inorganic elements such as alkali metals, sulfur, chlorine, and some heavy metals are partly released to the gas phase, which may cause problems in combustion facilities bec...

Effects on Particle Size Distribution from the Diesel Engine Operating on RME-Biodiesel with EGR

Abstract: In the present study, the effects of the neat biodiesel (rapeseed methyl ester, RME) fueled diesel engine with the use of EGR on the particle size distribution were examined The combustion of REM significantly improves the engine smoke and total particle mass but increases both NOx and particle concentration with low aerodynamic diameters (<0091 μm) when compared to the diesel (ultralow sulfur diesel, ULSD) fueled engine Although the particle size and mass distribution were not affected significantly by the different EGR additions, the particle total number and mass were increased considerably for both fuels For the RME fueled engine, the EGR addition reduces the particles in the lowest aerodynamic diameter measured (0046 μm) The use of EGR better suits the RME combustion, as apart from resulting in the higher NOx reduction, it maintained the smoke (soot, particulate matter) at relatively low levels The results are also confirming that it is challenging to reduce simultaneously total particle mass

Biodiesel from Castor Oil: A Comparison of Ethanolysis versus Methanolysis

Abstract: The transesterification reactions of castor oil with ethanol and methanol as transesterification agents were studied in the presence of several classical catalytic systems. The effects of the nature of the alcohol and catalyst on the yields of monoalkyl fatty acid esters were evaluated. The results indicate that biodiesel can be obtained by transesterification of castor oil using either ethanol or methanol as the transesterification agent. Similar yields of fatty acid esters may be obtained following ethanolysis or methanolysis; however, the reaction times required to attain them are very different, with methanolysis being much more rapid.

Electricity Production from Steam-Exploded Corn Stover Biomass

Abstract: Electricity generation using microbial fuel cells (MFCs) was examined from corn stover waste biomass using samples prepared through either neutral or acid steam-exploded hydrolysis processes that convert the hemicellulose to soluble sugars. Maximum power densities in fed-batch tests using an air-cathode MFC were 371 ± 13 mW/m2 and 367 ± 13 mW/m2 for the neutral and acid hydrolysates (1000 mg-COD/L, 250 Ω). Power output exhibited saturation kinetics with respect to fuel concentration, with predicted maximum power densities of Pmax = 475 mW/m2 and half-saturation constants of Ks = 347 mg/L (neutral) and Pmax = 422 mW/m2 and Ks = 170 mg/L (acid). Coulombic efficiencies (CEs) were comparable to that found using carbohydrates in this type of MFC, with values ranging from 20 to 30% for both hydrolysates. All sugars (monomeric or oligomeric) were completely utilized, with overall biochemical oxygen demand (BOD) removal efficiencies of 93 ± 2% (neutral) and 94 ± 1% (acid). Power output could be increased by using...

Investigation of Chemical Looping Combustion by Solid Fuels. 2. Redox Reaction Kinetics and Product Characterization with Coal, Biomass, and Solid Waste as Solid Fuels and CuO as an Oxygen Carrier

Abstract: This paper is the second in a series of two on the investigation of the chemical looping combustion (CLC) of solid fuels. The first paper put forward the concept of the CLC of solid fuels using a circulating fluidized bed as a reactor and Cu−CuO as the oxygen carrier, which was based on an analysis of oxygen transfer capability, reaction enthalpy, and chemical equilibrium. In this second paper, we report the results of the evaluation of the reduction of CuO reduced by solid fuels such as coal and some other “opportunity” solid fuels. Tests on the reduction of CuO by the selected solid fuels were conducted using simultaneous differential scanning calorimetry and thermogravimetric analysis, which simulates a microreactor. An attached mass spectrometer (MS) was used for the characterization of evolved gaseous products. The X-ray diffractometer (XRD) and scanning electron microscope (SEM) were used for the characterization of the solid residues. Results strongly supported the feasibility of CuO reduction by s...

Hydrogen Production via Steam Reforming of the Aqueous Phase of Bio-Oil in a Fixed Bed Reactor

Abstract: Hydrogen produced from renewable energy sources is of great interest as an alternative to fossil fuels and as a means for power generation via fuel cells. The aqueous fraction of bio-oil can be effectively reformed to hydrogen-rich streams in the presence of active catalytic materials. In this paper, we present the experimental work carried out in a fixed bed reactor for the reforming of bio-oil. The performance of the reactor was studied at various conditions and compared to the values theoretically predicted by thermodynamic equilibrium. The effect of reaction temperature, steam-to-carbon ratio in the feed, and space velocity was investigated in the presence of a commercial nickel catalyst. Runs were conducted with acetic acid, acetone, and ethylene glycol, representative model compounds of bio-oil, and the aqueous phase of a real bio-oil derived from beech wood. The results of the selected model compounds show that all can be effectively reformed with hydrogen yields up to 90% at reaction temperatures ...

Fast, Easy Preparation of Biodiesel Using Microwave Heating

Abstract: The preparation of biodiesel using a scientific microwave apparatus offers a fast, easy route to this valuable biofuel with advantages of a short reaction time, a low oil/methanol ratio, and an ease of operation. The methodology allows for the reaction to be run under atmospheric conditions; it is complete in a matter of a few minutes and can be performed on batch scales up to 3 kg of oil at a time. It can be utilized with new or used vegetable oil and with methanol or ethanol with a 1:6 ratio of oil/alcohol.

Base-Catalyzed Fast Transesterification of Soybean Oil Using Ultrasonication

Abstract: There is an increasing demand for alternative fuels that are environmentally friendly, especially because of the fact that crude petroleum reserves are dwindling. Also, research on alternative fuels is essential for increased energy security. Biodiesel is a renewable, biodegradable, and nontoxic fuel. At present, biodiesel is primarily produced in batch reactors in which the required energy is provided by heating accompanied by mechanical mixing. Alternatively, ultrasonic processing is an effective way to attain required mixing while providing the necessary activation energy. We found that, using ultrasonication, a biodiesel yield in excess of 99% can be achieved in a remarkably short time duration of 5 min or less in comparison to 1 h or more using conventional batch reactor systems.

High-temperature air/steam-blown gasification of coal in a pressurized spout-fluid bed

Abstract: The concept of high-temperature air/steam-blown gasification technology for converting coal into low-caloric-value gas for power generation is proposed and evaluated experimentally. Preliminary experiments are performed in a 0.1 MW thermal input pressurized spout-fluid bed gasifier. The influences of the gasifying agent preheat temperature, the gasification temperature and pressure, the equivalence ratio, the ratio of steam-to-coal on gas composition, gas higher heating value, carbon conversion, and cold gas efficiency are examined. The experimental results prove the feasibility of high-temperature air/steam-blown gasification process. The gas heating value is increased by 23%, when the gasifying agent temperature is increased from 300 to 700 °C. For the operation conditions studied, the results show that gasification temperature is the most important factor influencing coal gasification in the spout-fluid bed. The gasifier performance is improved at elevated pressure mainly due to the better fluidization...

Mechanism of Palm Oil Waste Pyrolysis in a Packed Bed

Abstract: To better understand the process mechanism, pyrolysis of palm oil wastes was investigated at different temperatures in a packed bed, with focus on the changing of chemical structure and physical characteristics of solid residues and gas-releasing properties. First, three palm oil wastes were pyrolyzed with temperature increasing from the ambient to 1000 °C, and the main products from it were solid charcoal, liquid oil, and hydrogen-rich gas. The gas component mainly consisted of H2, CO2, CO, and CH4 together with trace C2H4 and C2H6. CO and CO2 evolved out at lower temperature (<450 °C), while H2 released at higher temperature (600−700 °C). Second, the decomposition property of biomass shell was analyzed at variable temperatures (300, 400, ..., 1000 °C). The pyrolysis products were thoroughly identified using various approaches (including micro-GC, FTIR, GC-MS, ASAP2010, SEM, and CNHS/O analyzer) to understand the influence of temperature on product properties and, thus, reaction mechanism involved. Start...

Measurements of Molecular Diffusion Coefficients of Carbon Dioxide, Methane, and Propane in Heavy Oil under Reservoir Conditions

Abstract: In this paper, the so-called pressure decay method is applied to measure the molecular diffusivities of carbon dioxide, methane, and propane in heavy oil. In the experiment, a gaseous solvent is ma...