Sandun Fernando

A comparative study of exhaust emissions using diesel-biodiesel-ethanol blends in new and used engines.

The monoalkylesters of fatty acids derived from vegetable oils or animal fats are considered an attractive alternative fuel for diesel engines. This interest is based on a number of properties of biodiesel, including the fact that it is produced from a renewable resource and its potential to reduce exhaust emissions. Although several studies have been performed on biodiesel emissions, the results have been contradictory, with some studies reporting a reduction of nitrogen oxides (NOx) emissions while others report an increase. Adjusting engine parameters like exhaust gas recirculation (EGR), retarding injection timing, and using multiple injection strategies has reduced NOx to some extent. The objective of this study was to evaluate the effect on exhaust gas emissions of blending biodiesel and ethanol into conventional diesel fuel. Ethanol could be added to diesel in limited quantities along with biodiesel since biodiesel stabilizes the ternary system by acting as an amphiphile. This article illustrates the emission characteristics of diesel-biodiesel-ethanol (DBE) fuel blends on one used engine and two new engines. DBE is a new form of oxygenated diesel fuel blend and has the potential to reduce NOx emissions and to serve as an alternative to diesel fuel. The blend ratios (diesel:biodiesel:ethanol) by volume used in this study were 70:25:5, 70:20:10, and 70:15:15. The results with DBE showed a significant reduction in NOx emissions in new engines with increased ethanol concentration, whereas with the old engine under similar conditions, an increased NOx emissions profile was observed. CO emission increased with increasing ethanol proportion in the blends in both new and old engines.

Glycerin steam reforming for hydrogen production.

Biodiesel production is expected to grow steadily in the future. In converting vegetable oils into biodiesel, approximately 10% (w/w) of glycerin is produced as a by-product. With the increasing production of biodiesel, there would be glut of glycerin in the world market; therefore, it is essential to find useful applications for this by-product. Glycerin is a potential feedstock for hydrogen production because one mole of glycerin can produce up to four moles of hydrogen. The objective of this study was to develop, test, and characterize promising catalysts for hydrogen production from steam reforming of glycerin. The following five catalysts were prepared on ceramic foam monoliths (92% Al2O3, 8% SiO2): rhodium-cerium, rhodium-cerium-platinum, ruthenium-yttrium, nickel, and iridium. The catalysts were prepared by the incipient wetness technique. This article discusses selectivity data of the selected gases resulting from the glycerin steam reforming process. The study found that the rhodium-cerium-platinum catalyst was the most selective towards hydrogen under the experimental conditions investigated (700°C, 1 atm, and gas hourly specific velocity of 9.2 × 104 h-1). The glycerin conversion was 100% with all the catalysts tested.

High Temperature Water Gas Shift Reaction over Nickel Catalysts for Hydrogen Production: Effect of Supports, GHSV, Metal Loading, and Dopant Materials

The paper presents the recent advances of water-gas shift process using supported nickel catalysts. The effect of different supports, nickel loading, gas hourly space velocity, dopant materials, on the catalyst activity, H2 yield, and H2 selectivity are discussed. Ceria promoted nickel catalyst supported on powder alumina (Ni/CeO2-Al2O3) demonstrated the best performance. The performance of this catalyst was affected by the amount of nickel loading. The addition of small amounts of cobalt or chromium as a dopant material resulted in a considerable increase of the catalyst performance. The prepared catalysts were also compared with a commercial catalyst (Shift Max 120). It was observed that either of the doped or undoped Ni/CeO2-Al2O3 catalysts revealed a much higher performance in term of activity, H2 yield, and H2 selectivity, as compared to a commercial one.

Mississippi State Biodiesel Production Project

Biodiesel is a renewable fuel conventionally generated from vegetable oils and animal fats that conforms to ASTM D6751. Depending on the free fatty acid content of the feedstock, biodiesel is produced via transesterification, esterification, or a combination of these processes. Currently the cost of the feedstock accounts for more than 80% of biodiesel production cost. The main goal of this project was to evaluate and develop non-conventional feedstocks and novel processes for producing biodiesel. One of the most novel and promising feedstocks evaluated involves the use of readily available microorganisms as a lipid source. Municipal wastewater treatment facilities (MWWTF) in the USA produce (dry basis) of microbial sludge annually. This sludge is composed of a variety of organisms, which consume organic matter in wastewater. The content of phospholipids in these cells have been estimated at 24% to 25% of dry mass. Since phospholipids can be transesterified they could serve as a ready source of biodiesel. Examination of the various transesterification methods shows that in situ conversion of lipids to FAMEs provides the highest overall yield of biodiesel. If one assumes a 7.0% overall yield of FAMEs from dry sewage sludge on a weight basis, the cost per gallon of extracted lipid would be

Base Catalyzed Fast-Transesterification of Soybean Oil Using Ultrasonication

3.11. Since the lipid is converted to FAMEs, also known as biodiesel, in the in Situ extraction process, the product can be used as is for renewable fuel. As transesterification efficiency increases the cost per gallon drops quickly, hitting

A Comparative Study of Exhaust Emissions Using Diesel-Biodiesel-Ethanol Blends in New and Used Compression Ignition Engines

2.01 at 15.0% overall yield. An overall yield of 10.0% is required to obtain biodiesel at

Catalytic Biomass Gasification to Produce Sustainable Hydrogen

2.50 per gallon, allowing it to compete with soybean oil in the marketplace. Twelve plant species with potential for oil production were tested at Mississippi State, MS. Of the species tested, canola, rapeseed and birdseed rape appear to have potential in Mississippi as winter annual crops because of yield. Two perennial crops were investigated, Chinese tallow tree and tung tree. High seed yields from these species are possible because, there stature allows for a third dimension in yield (up). Harvest regimes have already been worked out with tung, and the large seed makes shedding of the seed with tree shakers possible. While tallow tree seed yields can be mind boggling (12,000 kg seed/ha at 40% oil), genotypes that shed seed easily are currently not known. Efficient methods were developed to isolate polyunsaturated fatty acid methyl esters from bio-diesel. The hypothesis to isolate this class of fatty acids, which are used as popular dietary supplements and prescription medicine (OMACOR), was that they bind transition metal ions much stronger than their harmful saturated analogs. AgBF4 has the highest extraction ability among all the metal ions tested. Glycerol is a key product from the production of biodiesel. It is produced during the transesterification process by cleaving the fatty acids from the glycerol backbone (the fatty acids are used as part of the biodiesel, which is a fatty acid methyl ester). Glycerol is a non-toxic compound with many uses; however, if a surplus exists in the future, more uses for the produced glycerol needs to be found. Another phase of the project was to find an add-on process to the biodiesel production process that will convert the glycerol by-product into more valuable substances for end uses other than food or cosmetics, focusing at present on 1,3-propanediol and lactic acid.All three MSU cultures produced products at concentrations below that of the benchmark microorganisms. There was one notable isolate the caught the eye of the investigators and that was culture J6 due to the ability of this microorganism to co-produce both products and one in particularly high concentrations. This culture with more understanding of its metabolic pathways could prove a useful biological agent for the conversion of glycerol. Heterogeneous catalysis was examined as an alternative to overcome the disadvantages of homogeneous transesterification, such as the presence of salts in the glycerine phase and the continuous lost of catalyst. A maximum soy biodiesel yield of 85% was obtained by BaO in 14 minutes, whereas, PbO, MnO2, CaO and MgO gave a maximum yields of 84%, 80%, 78% and 66% respectively at 215°C. The overall reaction order of PbO, MnO2, BaO, CaO and MgO was found to be 1, 1, 3, 1 and 1 respectively. The highest rate constant was observed for BaO, which was 0.0085 g2.mole-2.min-1. The performance of biodiesel in terms of type (e.g., NOx, and CO) and quantity of emissions was tested using soy biodiesel, blends of biodiesel and ethanol, and differently aged diesel engines. It was determined that saturated methyl esters, and relatively high oxygen content in the fuel, caused by addition of ethanol, increased the NOx emissions from new diesel engines compared to petroleum diesel.

Hydrogen Separation from Synthesis Gas

There is an increasing demand for alternative fuels that are environmentally friendly especially due to the fact that crude petroleum reserves are dwindling. Biodiesel is a renewable, biodegradable and a non-toxic fuel. At present, biodiesel is primarily produced in batch reactors where 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 less than 5 minutes in comparison to one hour or more using conventional batch reactor systems.

SOYBEAN THRESHING MECHANISM DEVELOPMENT AND TESTING

The monoalkylesters of fatty acids derived from vegetable oils or animal fats, are considered as an attractive alternative fuel for diesel engines. This interest is based on a number of properties of biodiesel including the fact that it is produced from a renewable resource and its potential to reduce exhaust emissions. Although several studies have been performed on biodiesel emissions, the results have been contradictory with some studies reporting a reduction of NOx emissions while others reporting an increase. Also, thus far, there has been no promising method on record which has been successful in reducing biodiesel related NOx emissions. The objective of this study was to evaluate the effect of blending biodiesel and ethanol into conventional diesel fuel on exhaust gas emissions. Ethanol could be added to diesel in limited quantities along with biodiesel since biodiesel stabilizes the ternary system by acting as an amphiphile. This paper illustrates the emission characteristics of diesel-biodiesel-ethanol (DBE) fuel blends on one use and two brand new engines. DBE is a new form of oxygenated diesel fuel blend and have a potential to reduce NOx emissions and to be an alternative to diesel fuel. The blend ratio (diesel: Biodiesel: ethanol) by volume used in this study was 70:25:5, 70:20:10 and 70:15:15. The results from the operation of diesel engine with DBE showed a significant reduction in NOx emissions in new engines with increased ethanol concentration where as with the old engine under similar conditions, an increased NOx emissions profile was observed. CO emission increased with increasing ethanol proportion in the blends in both new and old engines.

Soybean Oil Based Four-Stroke Engine Crankcase Lubricants

Hydrogen is believed to be the future energy carrier because it produces power with no environmentally harmful emissions. However, current hydrogen production mainly use steam reforming of fossil fuels such as natural gas, oil, naphtha, and coal in which carbon dioxide ( CO2) as a byproduct is unavoidable. Alternatively, biomass gasification is an environmentally friendly way to produce hydrogen since it contributes zero net CO2 emissions. However, using conventional gasification processes results in relatively low hydrogen yields, increasing hydrogen composition in the flue gas of biomass gasification is of interest. Coupling a secondary reactor for water gas shift reaction downstream is commonly used for this purpose. However, the reaction needs an active catalyst. This paper discusses some catalysts that could be used to increase hydrogen composition through water gas shift reaction in biomass gasification. The promising catalysts include dolomite, nickel, and noble metal based catalysts.