Catalytic Conversion of Tall Oil to Renewable Diesel and Biodiesel
University of Louisiana at LafayetteChemical Engineering Department
Kiran Pathapati, Stephen Dufreche, Rakesh Bajpai, Mark Zappi
Source: U.S. Energy Information Administration, Annual Energy Review 2009
Source: U.S. Energy Information Administration, Annual Energy Review 2009
Why Biofuels?Forecasted shortages and increasing prices of fossil fuels
Feedstocks are the KeyTodays popular feedstocks include sugars from sugarcane, sugar beets, and sweet sorghum, along with starch from corn and wheat, and vegetable oil from soybeans or palm Drawbacks:Combine to produce just 3% of todays transportation fuel requirementBiodiesel and Ethanol are competitive in the market only due to subsidiesFood vs FuelIssues related to diesel engine performance
Example: Tall Oil
A yellow-black, foul-smelling, homogeneous mixture that consists of materials extracted from wood pulping waste liquors, such as resins, fatty acids, sterols, and/or alcohols of high molecular weight.
The principal components of CTO include saturated and unsaturated C18 FFA, resin acids and other non-acidic compounds. The global annual production of CTO is approx. 1.4 million tonnes, out of which about 750,000 tonnes is produced in the USAOn a pulp basis, each ton of pulp affords 140-220 pounds black liquor soaps, 70-110 pounds crude tall oil, yielding 30-50 pounds of TOFA.The main uses of tall oil fatty acids are alkyd resins, soaps, cleaners, detergents, surfactants, lubricants and ore flotation reagents and that of tall oil rosin acids are paper sizes, printing inks and adhesives.
Time of year or growing cycle of the tree.The particular species involved.Aging of the wood.The amount of heartwood.Pulping conditions.The efficiency of the system used to recover the tall oil.
Analysis range of American Crude Tall OilAcid no. 153 - 170Saponification no. 167 - 178 Iodine no. 165 - 176
Rosin acids, % 35 - 50Fatty acids, % 41 - 59Unsaponifiables, % 6 - 9Moisture, % 0.2 - 1.2
The oil is distilled into five components with different boiling points:
Tall oil heads (which boils first)Tall oil fatty acidsDistilled tall oil (a mixture of fatty and resin acids)Resin acids (collectively known as rosin)Pitch (the residue)
Renewable Diesel vs BiodieselThree defining characteristicsPrice Alternative, lower cost feedstocksProcess Uses traditional refinery processes. Catalytic cracking.Properties Chemically identical to petroleum diesel
Scope of ProjectBiodiesel from tall oil gives good yield percentage from TOFA fraction.
Catalytic cracking may convert other fractions of CTO along with TOFA effectively
Effect of Crude Tall Oil on commercial catalyst
EquipmentGC-MS with a catalyst bed built in.Custom configuration allows for cracking of a compound over catalyst in situ.Can accept solid, gas, or liquid samples.Mass input into MS is independent of flow over catalyst bed.
Transfer Line (200C)He
40 350CRX-1MS Column50 - 400C40 - 300CSample InjectorCatalyst BedSplit Flow1 mL/min15 mL/min14 mL/minPurge gas forcolumn changeMS-OpenSplit SystemHe, H2
Catalyst: ZSM-5ZSM-5 is a crystalline silica/alumina catalyst widely used in laboratory experiments and elucidation of cracking characteristics.
Catalyst CharacteristicsSiO2 / Al2O3 = 23 (36)Surface Area = 450 m2 / gParticle Diameter = 1 mPore Size = 0.55 nm
Results: Crude Tall Oil
TGA Analysis: CTO coke removal2.101%
TGA Analysis: CTO activity test6.000%
TGA analysis: TOFA coke removal1.489%
TGA analysis: TOFA activity test6.515%
Tall Oil Rosin Acids have effect on the catalyst.
Crude tall oil can be reacted along with the TOFA.
Results show that the crude tall oil can be cracked into fuel.
Comparison of obtained biodiesel with that of biodiesel obtained from soybean oil.Comparison of obtained green diesel with the petroleum diesel.
*As of 2008, transportation share of the U.S. petroleum consumption is 71%.The U.Stransportation sector is 97 percent reliant on oil,with 60 percent of this oil imported.In 2008, the U.S. used over 45 billion gallons of petroleum diesel fuel and 140 billion gallons of gasoline.Mobile sector greenhouse gas emissionsare projected to increase 37 percent over the next 25 years.
*This dependence on oil to meet our growing demand for travel leaves our economy vulnerable to price increases. In October 2003, oil was $25 a barrel. Recently, the cost has been as high as $100 a barrel, a fourfold increase. We are likely to see continued price fluctuations and increases due to rising costs associated with growing world oil demand, historic low capacities in oil-producing countries, refinery outages, and political instability in oil-rich nations and regions.The transportation sector dominates demand for liquid fuels, which grows from a 69-percent share of total consumption in 2007 to a 75-percent share in 2030.*The importance of bio-fuels for transport has become more and ,more important in the past years and this trend is expected to continueenvironmental Issues: Petroleum fuels have exacted a heavy environmental toll on the planet, and their impact is likely to worsen as dirtier energy supplies, such as heavy oil and coal, are tapped. As an alternative, biofuels offer the opportunity to reduce the emissions of both greenhouse gases (GHGs) and urban air pollutantsenergy security: Petroleum is a highly concentrated energy resource, and the worlds current transportation systems are almost completely dependent on it. As a result, the world economy is (or could be) at risk if oil supplies are disrupted in any of the relatively few countries that are significant oil exporters. As a result of concentrated wealth, social tensions, and inadequate political institutions, many of these countries are less-than-secure suppliers of the worlds most vital commodity. Biofuels promise to bring a much broader group of countries into the liquid fuel business, diversifying supplies and reducing the risk of disruption. And because they can be produced in most regions of the globe, the risks inherent in transporting these fuels over long distances will be reduced as well. In the long run, this is likely to help stabilize fuel prices.Economy: Oil imports account for almost half the U.S. trade deficit, which has an enormous impact on our economy and the creation of new jobs. A high trade imbalance from dependence on foreign oil also leaves our economy vulnerable to price hikes from supply disruptions. eveloping a stronger market for domestically produced biofuels in the United States will help alleviate the negative implications of our trade deficit and contribute to positive economic trends in the U.S. transportation sector. *The feedstock is the fundamental building block for a transportation fuel. One of the big debates in the emerging Bio-Economy involves the tradeoffs between growing agricultural crops for human consumption and animal feed versus biomass feedstocks for alternative fuels.: (i) deposits throughout the fuel and combustion systems, (ii) problems related to the poor cold-flow properties of FAME, (iii) low stability towards heat and oxidation, (iv) prone towards water absorption, (v) higher emissions of NOx relative to fossil type diesel and (vi) shortening of engine oils lifetime,
The impediments to significant expansion in the ethanol and biodiesel industries are the identification of additional economically viable alternative feedstocks The impediment to the use of hydrogen in the transportation sector is the high cost of production, the availability of supply infrastructure.
*increasing demand from developing economies.alternative, lower cost, non-food feedstocks.*tall oil is a dark. odorous liquid that is one of the two commercially imp by product from the sulfate process of paper manf. it is obtained by chemically treating the cooking liquor used in the operation of pulping wood for paper. Its name comes from the swedish word for pine, tall.*The principal components of CTO include saturated and unsaturated C18 FFA, free resin acids and other non-acidic compoundstall oil supplies about two thirds of the fatty acids used in the US for industrial purposes. *the exact comp of cto can vary widely. while the time of year the wood was harvested has little effect on the cto comp, the geographic location, wood type, and age have temendous effect. *the cto is upgraded by distillation to produce five major fractions.heads product consists of the lower boiling fractions such as palmitic acid, and some neutral compounds, whitle pitch fraction consists of mostly the higher boiling or nonvolatile unsaponifiable products.the dto contains a mixture of fatty acids and resin acids that can vary in conc.
the main fractions TOFA and TOR consist almost entirley of the respective fatty and resin acids. Price is driving the growth of renewable diesel markets worldwide.
The second defining characteristic of renewable diesel is the way it is processed. Compared with biodiesel, which combines virgin vegetable ils with alcohol, renewable diesel uses traditional refinery processes to produce clean