Blend Stock Research Articles

Improvement of heavy crude oil via catalytic cracking process for refining into valuable blending stocks

ABSTRACTIn this study, it was aimed to obtain the conversion of the heavy crude oil with 12.2° API gravity into the liquid fuel-like condensate fractions having different boiling points of gasoline (initial boiling point–180), kerosene (180–240°C), light diesel or distillate (240–290°C), and gas oil (290–360°C). A series of catalytic cracking runs were carried out on the pre-upgraded oil with using the molasses soil catalyst in different ratios of 0.0–10.0wt.%. The catalytic condensate and coke yields were found as 94.81wt.% and 2.42 wt.%, respectively, for the optimal catalyst ratio of 2.5wt.%. The optimal cracking condensate and its fractions were characterized via spectroscopic and analytical test methods. The results revealed that the catalytic condensate was more rich in view of n-paraffinic hydrocarbons with lower carbon number of C10–C12 found in diesel fuel.

2-Methylfuran: A bio-derived octane booster for spark-ignition engines

The efficiency of spark-ignition engines is limited by the phenomenon of knock, which is caused by auto-ignition of the fuel-air mixture ahead of the spark-initiated flame front. The resistance of a fuel to knock is quantified by its octane index; therefore, increasing the octane index of a spark-ignition engine fuel increases the efficiency of the respective engine. However, raising the octane index of gasoline increases the refining costs, as well as the energy consumption during production. The use of alternative fuels with synergistic blending effects presents an attractive option for improving octane index. In this work, the octane enhancing potential of 2-methylfuran (2-MF), a next-generation biofuel, has been examined and compared to other high-octane components (i.e., ethanol and toluene). A primary reference fuel with an octane index of 60 (PRF60) was chosen as the base fuel since it closely represents refinery naphtha streams, which are used as gasoline blend stocks. Initial screening of the fuels was done in an ignition quality tester (IQT). The PRF60/2-MF (80/20 v/v%) blend exhibited longer ignition delay times compared to PRF60/ethanol (80/20 v/v%) blend and PRF60/toluene (80/20 v/v%) blend, even though pure 2-MF is more reactive than both ethanol and toluene. The mixtures were also tested in a cooperative fuels research (CFR) engine under research octane number and motor octane number like conditions. The PRF60/2-MF blend again possesses a higher octane index than other blending components. A detailed chemical kinetic analysis was performed to understand the synergetic blending effect of 2-MF, using a well-validated PRF/2-MF kinetic model. Kinetic analysis revealed superior suppression of low-temperature chemistry with the addition of 2-MF. The results from simulations were further confirmed by homogeneous charge compression ignition engine experiments, which established its superior low-temperature heat release (LTHR) suppression compared to ethanol, resulting in better blending octane numbers. This work explores and provides a chemically sound explanation for the potential of 2-MF as an octane enhancer.

Production of Biodiesel using Waste Frying Oil for Diesel Engine

The ever-increasing demand of dwindling fuel has caused researchers worldwide to search for non-renewable sources. Depleting oil reserves, stringent environmental norms and fluctuating prices of petroleum-derived fuels have directed toward renewable sources energies like solar energy, wind energy, biofuel and so on. In this context, bio-origin fuels, such as biodiesel, are very promising and results in energy security and has environmental benefits. The aim of this work is to produce the biodiesel from waste vegetable frying oil, particularly soybean oil. India is one of the largest importers of soybean oil in the world. Subsequently, disposal of waste oil is a huge concern. Therefore, this paper provides an insight of the method employed for biodiesel production from waste soybean oil by transesterification reaction. The main objective of the present investigation was to evaluate suitability of waste soybean oil biodiesel (WSOME) as a blending stock in a compression ignition engine. Fuel blends with neat diesel (D100) on volumetric basis were prepared and they remained homogenous even after three months and no significant change was observed. The calorific value, kinematic viscosity and density of blends were found to decrease with increasing percentage of WSOME in D100. Therefore, it could be concluded that waste soybean oil biodiesel is a potential alternative fuel to be blended with diesel for CI engine application.

Effects of aromatic fluids on properties and stability of alternative marine diesels

Hydroprocessed renewable diesel (HRD-76) and synthesized isoparaffin (SIP-76) have been produced in sufficient quantity for testing by the US Navy, and demonstrated as compatible replacements or blend stock with marine diesel (NATO F-76). Operational limitations with respect to the lubricity, seal swell and cold-flow properties, however, need to be addressed before using 100% HRD-76 or SIP-76. Aromatics are known to improve seal swell and low-temperature characteristics. In this study, three commercial aromatic fluids (Aromatic 100, 150 and 200) produced from petroleum refining were added to HRD-76 and SIP-76 at various concentrations to investigate their impacts on the properties of the biofuel blend. The composition, hydrogen content and physicochemical properties of these aromatic fluids were determined according to ASTM methods and compared with that of biofuels and F-76. The seal-swell capability of the aromatic fluids and biofuel blends was investigated using nitrile O-rings, while the effects of aromatic fluids on fuel low-temperature quality were evaluated using differential scanning calorimetry. In addition, ASTM D5304 and D2274 tests were conducted to investigate the impacts of adding aromatics to biofuels on long-term storage and oxidative stabilities. Although the composition and characteristics of these three aromatics fluids varied, all were capable of inducing o-ring seal swell and adjusting the density of biofuels without significantly affecting the biofuels’ stabilities. HRD-76 and aromatic fluid blends also exhibited liquid to solid phase transitions at lower temperatures and greater hydrophilicity than neat HRD-76.

Cost to produce liquid biofuel from invasive eastern redcedar biomass

Biomass harvested from invasive plant species has been proposed for use as lignocellulosic feedstock for the production of advanced biofuels as a way to mitigate the indirect land use issues associated with the production of dedicated energy crops. Encroachment of eastern redcedar (Juniperus virginiana L.) has reduced the forage productivity of North American Great Plains grasslands ranging from Texas in the South to Alberta in the North. The objective of this study is to develop and demonstrate a modeling system that can be used to determine the minimum selling price of biofuel. A fast pyrolysis process that exclusively uses eastern redcedar biomass to produce gasoline and diesel blend stock is assumed. A mixed integer mathematical programming model is constructed and applied to a 15 county case study region from which eastern redcedar may be collected. The modeling system considers the growth rate of unharvested trees to determine the optimal biorefinery location, the optimal harvest locations for each of 20 years, and the minimum selling biofuel price. To fulfill 2 Gg d−1 feedstock requirements for the expected life of the biorefinery, 73% of the trees growing in year zero in the case study region would be required. For a 313 dm3 Mg−1 conversion rate, and with biorefinery ownership, operating and maintenance cost of 630 $ m−3, the expected cost to deliver feedstock is estimated to be 61 $ Mg−1, and the estimated minimum selling biofuel price is 830 $ m−3.

Formulation of Sasol Isomerized Paraffinic Kerosene Surrogate Fuel for Diesel Engine Application Using an Ignition Quality Tester

Sasol isomerized paraffinic kerosene (IPK) is a coal-derived synthetic fuel under consideration as a blending stock with jet propellant 8 (JP-8) for use in military equipment. However, Sasol IPK is a low ignition quality fuel with derived cetane number (DCN) of 31. The proper use of such alternative fuels in internal combustion engines (ICEs) requires the modification in control strategies to operate engines efficiently. With computational cycle simulation coupled with surrogate fuel mechanism, the engine development process is proved to be very effective. Therefore, a methodology to formulate Sasol IPK surrogate fuels for diesel engine application using ignition quality tester (IQT) is developed. An in-house developed matlab code is used to formulate the appropriate mixture blends, also known as surrogate fuel. And aspen hysys is used to emulate the distillation curve of the surrogate fuels. The properties of the surrogate fuels are compared to those of the target Sasol IPK fuel. The DCNs of surrogate fuels are measured in the IQT and compared with the target Sasol IPK fuel at the standard condition. Furthermore, the ignition delay, combustion gas pressure, and rate of heat release (RHR) of Sasol IPK and its formulated surrogate fuels are analyzed and compared at five different charge temperatures. In addition, the apparent activation energies derived from chemical ignition delay of the surrogate fuel and Sasol IPK are determined and compared.

An Experimental Study on the Influence of Ethanol and Automotive Gasoline Blends

The objective of this work is to investigate the production possibility of high octane environmental ethanol gasoline blends based on Euro specifications. The environmental gasoline is the key element to keep the environment safe and clean. Moreover, it reduces gas emissions after combustion of gasoline. One of the main methods to produce the environmental gasoline is blending gasoline with oxygenated compounds such as ethanol. Ethanol is chosen among other oxygenated compounds as it has a high influence on physico-chemical characteristics of gasoline rather than other oxygenated compounds. In addition, it has a high octane number as well as it is not polluting the environment and clean additive. In the experimental study, the choice of environmental gasolines are based on Euro- 3 specifications for samples without ethanol blend and Euro-5 specifications for samples with ethanol blend; after upgrading. Various blend stocks have been prepared which have reformate, isomerate, full refinery naphtha (FRN), heavy straight run naphtha (HSRN), hydrocracked naphtha, heavy hydrocracked naphtha, coker naphtha and heavy coker naphtha. In this study, ASTM standard methods are performed for spark ignition fuels to characterize its physical and chemical properties. The results show that one has exhibited the optimum specifications of Euro-3 and thus its physico-chemical characteristics are 755.11 Kg/m3 of density, 55.88 of °API and 95 of RON, 88 of MON, 40% by volume of aromatic content and 0.66% by volume of benzene content. Moreover, ASTM distillation curve shows that the volume percentage at 150°C is 83. At the same time, the final boiling point (FBP) and recovery volume percent are 198°C is 96% respectively. While another sample has the poorest physical as well as chemical properties so that it is blended with ethanol to upgrade its characteristics. Therefore, the target is determining the optimum ethanol volume percent to be blended with poorest sample to yield the highest properties of gasoline. These blends are namely as E0, E5, E10, E15, E20. The results indicate that E5 is the optimum one for Euro-5 specifications after upgrading and thus its physico-chemical characteristics are 745.55 Kg/m3 of density, 58 of oAPI, 101 of RON, 98 of MON, 32.65% by volume of aromatic content and 0.47% by volume of benzene content. Moreover, ASTM distillation curve illustrates that the volume percentage at 150°C is 75. At the same time, the final boiling point (FBP) and recovery volume percent are 190°C and 97% respectively. In addition, its Reid vapor pressure equals 8.1 psi and the heat of combustion equals 35 MJ/L. In the final, Blending gasoline with ethanol is an essential issue concerning the production of environmental gasolines.

Refinery ignored safety risks

The Tesoro refinery in Martinez, Calif., for years ignored safety problems and fostered a weak safety culture, the U.S. Chemical Safety Board says in a report released on Aug. 2. Board officials urged Tesoro and other refiners to elevate the importance of process safety and encouraged state and local regulators to frequently conduct preventive safety inspections of the facility. Triggering CSB’s report and investigation were incidents in February and March 2014 at the facility’s alkylation unit, which carries out a process common at U.S. refineries. Tesoro’s unit uses sulfuric acid as a catalyst to reformulate low-value hydrocarbons, such as propane and butane, to produce a premium, high-octane gasoline blend stock. The first of the two accidents was the result of a piping failure that released some 38,000 kg of sulfuric acid over two hours and burned two employees. Tesoro initially characterized the accident as minor and refused to allow CSB

Effects of n-Butanol Blending with Jatropha Methyl Esters on Compression Ignition Engine

The diminishing oil reserves, environmental degradation and increasing prices of petroleum-derived fuels have necessitated the search for cleaner and renewable alternative fuels, such as biodiesel. In this context, the objective of this research is to evaluate the suitability of n-butanol as a blending stock in jatropha methyl ester (JME) for use in a C.I. engine as substitute of diesel and to evaluate the performance and emission characteristics of an unmodified diesel engine. Three blends of n-butanol–JME (5, 10 and 20 % n-butanol with JME on volumetric basis) were prepared. Fuel properties including calorific value, kinematic viscosity and density of blends were found to decrease with increasing percentage of n-butanol in JME. The brake thermal efficiency of the engine was higher for blends and was found to increase by increasing the percentage of n-butanol in the blends. Carbon monoxide (CO), the oxides of nitrogen (NOX) and smoke opacity of blends were found lower than JME during the whole experimental range. However, unburnt hydrocarbon (HC) emission was found to have slightly increased. The experimental results suggested that the engine performance had improved and emissions have significantly reduced (except HC) with blends of n-butanol and JME in comparison with neat JME. Therefore, it could be concluded that n-butanol is a potential alternative fuel to be blended with JME for diesel engine application.

Direct production of high octane gasoline and ULSD blend stocks by LCO hydrocracking

Hydrocracking of light cycle oil (LCO) is of great scientific and industrial importance to obtain high quality of gasoline and diesel. In this work, a novel LCO hydrocracking technology (FD2G) was proposed, and three kinds of hydroprocessing catalysts (i.e., FC-14, FC-24 and FC-26) were tested under different pilot-scale operational conditions and/or types. All the three catalysts are found to be active for direct production of high octane gasoline and ultra low sulfur diesel (ULSD) blend stocks, and the FC-24 catalyst is the most active and selective toward production of high octane gasoline. The quality of gasoline and diesel products is highly sensitive to pressure and operation type. Furthermore, the FC-24 catalyst was also tested in a large-scale industrial plant. It is found that the yield of gasoline blend stock reaches 30–50wt%, the octane number of gasoline is 91–94 and the sulfur content is less than 10μg/g; the cetane number of diesel blend stock increases 10–14 units in comparison to the feed stock, and the sulfur content is less than 10μg/g.

Tailoring the Transport Properties of Zeolitic Imidazolate Frameworks by Post-Synthetic Thermal Modification.

Understanding how to control transport properties of zeolitic imidazolate frameworks (ZIFs) is critical to extend ZIF-based membranes and adsorbents to a wide spectrum of gas and vapor separations. In this work, we report a facile post-synthetic thermal modification (PSTM) technique to tailor ZIFs' transport properties by balancing diffusivity and diffusion selectivity. With controllable dissociation of framework methyl groups from a precursor ZIF (ZIF-8), we have prepared thermally modified ZIFs showing substantially increased n-butane diffusivity and attractive n/iso-butane diffusion selectivity. Hybrid ZIF/polymer mixed-matrix membranes formed using these thermally modified ZIFs are expected to deliver attractive butane isomer separation performance. Membranes based on such materials can potentially be used to retrofit refinery alkylation units for producing premium gasoline blending stocks.

An overview of the applications of furfural and its derivatives

Recently, furfural, “the sleeping beauty bio-renewable chemical” has gained a renewed attention as a potential chemical for the production of biofuels and biochemicals. Furfural is the most commonly produced industrial chemical because its production is very flexible. It is one of the top value-added chemicals that can be produced from biomass. Furfural and its derivatives have been extensively used in plastics, pharmaceutical and agrochemical industries. Furfural is a natural precursor to a range of furan-based chemicals and solvents such as dihydropyran, methyltetrahydrofuran, tetrahydrofuran, methylfuranfurfuryl alcohol, tetrahydrofurfuryl alcohol and furoic acid. Furfural and its derivatives have been widely applied as fungicides and nematicides, transportation fuels, gasoline additives, lubricants, resins, decolorizing agents, jet fuel blend stocks, drugs, insecticides, bio-plastics, flavor enhancers for food and drinks, rapid all-weather repair system for bomb-damaged runways and pot holes and also for wood modification and book preservation.

Effect of Cetane Improver on Combustion and Emission Characteristics of Coal-Derived Sasol Isomerized Paraffinic Kerosene in a Single Cylinder Diesel Engine

Sasol isomerized paraffinic kerosene (IPK) is a coal-derived synthetic fuel under consideration as a blending stock with JP-8 for use in military ground vehicles. Since Sasol IPK is a low ignition quality fuel with derived cetane number (DCN) of 31, there is a need to improve its ignition quality. This paper investigates the effect of adding different amounts of Lubrizol 8090 cetane improver to Sasol IPK on increasing its DCN. The experimental investigation was conducted in a single cylinder research type diesel engine. The engine is equipped with a common rail injection system and an open engine control unit. Experiments covered different injection pressures and intake air temperatures. Analysis of test results was made to determine the effect of cetane improver percentage in the coal-derived Sasol IPK blend on auto-ignition, combustion and emissions of carbon monoxide (CO), total unburned hydrocarbon (HC), oxides of nitrogen (NOx), and particulate matter (PM). In addition, the effect of cetane improver on the apparent activation energy of the global auto-ignition reactions was determined.

Impact of biodiesel and renewable diesel on emissions of regulated pollutants and greenhouse gases on a 2000 heavy duty diesel truck

As part of a broad evaluation of the environmental impacts of biodiesel and renewable diesel as alternative motor fuels and fuel blends in California, the California Air Resources Board's (CARB) Heavy-duty Diesel Emission Testing Laboratory conducted chassis dynamometer exhaust emission measurements on in-use heavy-heavy-duty diesel trucks (HHDDT). The results presented here detail the impact of biodiesel and renewable diesel fuels and fuel blends as compared to CARB ULSD on particulate matter (PM), regulated gases, and two greenhouse gases emissions from a HHDDT with a 2000 C15 Caterpillar engine with no exhaust after treatment devices. This vehicle was tested over the Urban Dynamometer Driving Schedule (UDDS) and the cruise portion of the California HHDDT driving schedule. Three neat blend stocks (soy-based and animal-based fatty acid methyl ester (FAME) biodiesels, and a renewable diesel) and CARB-certified ultra-low sulfur diesel (CARB ULSD) along with their 20% and 50% blends (blended with CARB ULSD) were tested. The effects of blend level on emission characteristics were discussed on g·km−1 basis. The results showed that PM, total hydrocarbon (THC), and carbon monoxide (CO) emissions were dependent on driving cycles, showing higher emissions for the UDDS cycles with medium load than the highway cruise cycle with high load on per km basis. When comparing CARB ULSD to biodiesels and renewable diesel blends, it was observed that the PM, THC, and CO emissions decreased with increasing blend levels regardless of the driving cycles. Note that biodiesel blends showed higher degree of emission reductions for PM, THC, and CO than renewable diesel blends. Both biodiesels and renewable diesel blends effectively reduced PM emissions, mainly due to reduction in elemental carbon emissions (EC), however no readily apparent reductions in organic carbon (OC) emissions were observed. When compared to CARB ULSD, soy- and animal-based biodiesel blends showed statistically significant increases in nitrogen oxides (NOx) emissions for 50% or higher biodiesel blends. The 20% blends of the biodiesels showed no statistically significant effect on NOx emissions on any cycle. In contrast, renewable diesel slightly decreased NOx emissions and the degree of reduction was statistically significant for 50% or higher blends over the UDDS cycle, but not at the 20% blends. The highway cruise cycles did not show a statistically strong NOx emission trend with increasing blend level of renewable diesel. Biodiesel and renewable fuel impacts on two greenhouse gases, CO2 and N2O emissions were of lower magnitude when compared to other regulated pollutants emissions, showing a change in their emissions within approximately ±3% from the CARB ULSD.

Pyrolysis of Woody Residue Feedstocks: Upgrading of Bio-oils from Mountain-Pine-Beetle-Killed Trees and Hog Fuel

Liquid transportation fuel blendstocks were produced by pyrolysis and catalytic upgrading of woody residue biomass. Mountain-pine-beetle-killed (MPBK) wood and hog fuel from a saw mill were pyrolyzed in a 1 kg/h fluidized bed reactor and, subsequently, upgraded to hydrocarbons in a continuous fixed bed hydrotreater. Upgrading was performed by catalytic hydrotreatment in a two-stage bed at 170 and 405 °C with a per bed liquid hourly space velocity between 0.17 and 0.19. The overall yields from biomass to upgraded fuel were similar for both feeds (24–25%), despite the differences in bio-oil (intermediate) mass yield. The pyrolysis bio-oil mass yield was 61% from MPBK wood, and subsequent upgrading of the bio-oil gave an average mass yield of 41% to liquid fuel blend stocks. Hydrogen was consumed at an average of 0.042 g/g of bio-oil fed, with a final oxygen content in the product fuel ranging from 0.3 to 1.6% over the course of the test. Comparatively, for hog fuel, the pyrolysis bio-oil mass yield was lower at 54% because of inorganics in the biomass, but subsequent upgrading of that bio-oil had an average mass yield of 45% to liquid fuel, resulting in a similar final mass yield to fuel compared to the cleaner MPBK wood. Hydrogen consumption for the hog fuel upgrading averaged 0.041 g/g of bio-oil fed, and the final oxygen content of the product fuel ranged from 0.09 to 2.4% over the run. While it was confirmed that inorganic-laden biomass yields less bio-oil, this work demonstrated that the resultant bio-oil can be upgraded to hydrocarbons at a higher yield than bio-oil from clean wood. Thus, the final hydrocarbon yield from clean or residue biomass pyrolysis/upgrading was similar.

Studies on biodiesel produced from Jatropha oil in Cambodia by a non-catalytic using C2H5OH

Different technologies are currently available for biodiesel production from various kinds of lipid containing feedstock. Among them, the alkaline-catalyzed methods are the most widely studied. However, here are several disadvantages related to biodiesel production using alkaline catalysts such as generation of wastewater, catalyst deactivation, difficulty in the separation of biodiesel from catalyst and glycerin, etc. To limit the problems mentioned above, in this study, biodiesel is produced by a non-catalytic using C2H5OH. The effect of experimental variables (the molar ratio ethanol/oil of 41.18:1 – 46.82:1, reaction times of 50 - 90 minutes and reaction temperatures of 2750C - 2950C) on the yield of biodiesel was studied. The 96% yield of Cambodia biodiesel of reaction between C2H5OH and Jatropha Oil at 46:1 at temperature 2900C at 60 minutes no using catalysts. Obtained biodiesel fuel was up to the International Standard ASTM D6751 for biodiesel fuel blend stock (B100).

Novel Data Abstraction Strategy Utilizing Gas Chromatography–Mass Spectrometry Data for Fuel Property Modeling

The high cost and limited availability of emerging alternative fuels and/or fuel blending stocks with unknown compositions are often major impediments to the certification of these materials as Fit-For-Purpose (FFP) for the U.S. Navy. A method was desired whereby a candidate fuel could be rapidly prescreened to determine if it would be suitable for further, more-extensive FFP testing. The goal of this research was to employ statistical analysis strategies to establish linkages between the chemical constituency of any given fuel or fuel stock, regardless of type or source, and the resultant performance, and/or fuel properties. A chemical profiler developed during the course of this work has previously been used to quantify the constituencies of fuels using gas chromatography–mass spectrometry (GC-MS) data. These constituencies were then correlated to specification properties using partial least-squares regression modeling reconfigured into a multistep, iterative strategy. While this modeling strategy was s...

Composition and Sources of the Organic Particle Emissions from Aircraft Engines

We report a positive matrix factorization (PMF) analysis of organic particulate material (PM) emissions of aircraft engine exhaust that includes data from five different aircraft engines and two different fuels (petroleum jet fuel and a Fischer-Tropsch fuel) collected over three field missions. PMF of aerosol mass spectrometer (AMS) data was used to identify six distinct factors: two lubrication oil factors, two aliphatic factors, an aromatic factor, and a siloxane factor. Of these, the lubrication oil factors and the siloxane factor were noncombustion sources. The siloxane factor was attributed to silicone tubing used in the sampling system deployed in one of the three missions included in this study, but not the other two. The two lubrication oil factors correlate with the two different lubrication oils used by the aircraft engines evaluated in this study (Mobil II and Air BP) as well as minor differences presumably due to variation in the blend stocks, temperature history, and analytical factors. Overall, the sum of the aliphatic and aromatic factors decreased with increasing power, as expected based on known trends in VOC emissions. The aliphatic #1 factor correlated with soot emissions, especially at power conditions where EIm-soot was greater than 30 mg kg?1. The aliphatic factor #2 mass spectrum shared some similarities with ambient aerosol organic PM present during the tests and correlated most strongly with dilution levels, two observations that suggest that aliphatic #2 contains components found in ambient aerosol. The aromatic factor correlated with benzene emissions, especially at low power conditions were EIm-benzene was greater than 0.03 mg kg?1. Our results improve the current understanding of aircraft PM composition. Copyright 2014 American Association for Aerosol Research

Toxicological Assessment of Heavy Straight Run Naphtha in a Repeated Dose/Reproductive Toxicity Screening Test

Gasoline blending stocks (naphthas) are comprised of normal, iso- and cycloparaffins and aromatic hydrocarbons with carbon numbers ranging from C4 to C12. Heavy straight run naphtha (HSRN, CAS number 64741-41-9) was selected for toxicity screening because substances of this type contain relatively high levels (28%) of cycloparaffins by comparison to other naphtha streams and the data complement toxicity information on other gasoline blending streams. Rats were exposed by inhalation to wholly vaporized material at levels of approximately 100, 500, or 3000 parts per million (ppm) daily to screen the potential for systemic toxicity, neurotoxicity, reproductive toxicity, and developmental effects to postnatal day 4. All animals survived the treatment period. Principal effects of repeated exposure included increased liver weights in males and females, increased kidney weights in males, and histological changes in the thyroid, secondary to liver enzyme induction. These changes were not considered to be toxicologically meaningful and are not relevant to humans. There were no treatment-related effects in functional observation tests or motor activity; no significant reductions in fertility or changes in other reproductive parameters; and no evidence of developmental toxicity in offspring. The overall no observed adverse effect concentration was 3000 ppm (approximately 13, 600 mg/m(3)). In conclusion the HSRN effects on liver and kidney are consistent with the results of other studies of volatile fractions or other naphthas or formulated gasoline, and there were no HSRN effects on neurological developmental or reproductive parameters.

The challenge of biodiesel production from oil palm feedstock in Nigeria

Nigeria has joined the league of countries seeking for alternatives to fossil fuels. Biofuel has emerged as a credible alternative and blend stock for the dwindling petroleum resources. Nigeria is committed to blending biodiesel with petrodiesel up to 20%. This paper evaluates the challenge of biodiesel production from oil palm feedstock in Nigeria. The study found that biodiesel production in Nigeria could be challenged by feedstock supply shortages, poor quality of the feedstock, technological challenges and poor policy framework. Oil palm in Nigeria is mostly processed by smallholders, producing oils of low quality due to high free fatty acid (FFA), moisture and impurities above limits for biodiesel production. Pretreatment techniques, which are used to upgrade the oil, could increase the cost of the resultant biodiesel. Because of the poor quality of the feedstock, enzymatic transesterification is a more feasible method for biodiesel production. The paper concludes by suggesting the use of inedible oil as feedstock, production of lipase for enzymatic transesterification and upgrading the Nigerian policy and incentives.