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Title: Continuous Flow Solid-Catalytic Biodiesel Production Process

Publication Date:
Research Org.:
Idaho National Laboratory
Sponsoring Org.:
OSTI Identifier:
Report Number(s):
DOE Contract Number:
Resource Type:
Technical Report
Country of Publication:
United States

Citation Formats

None. Continuous Flow Solid-Catalytic Biodiesel Production Process. United States: N. p., 2007. Web. doi:10.2172/942155.
None. Continuous Flow Solid-Catalytic Biodiesel Production Process. United States. doi:10.2172/942155.
None. Thu . "Continuous Flow Solid-Catalytic Biodiesel Production Process". United States. doi:10.2172/942155.
title = {Continuous Flow Solid-Catalytic Biodiesel Production Process},
author = {None},
abstractNote = {},
doi = {10.2172/942155},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Mar 29 00:00:00 EDT 2007},
month = {Thu Mar 29 00:00:00 EDT 2007}

Technical Report:

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  • Oak Ridge National Laboratory (ORNL) and Nu-Energie, LLC entered into a Cooperative Research And Development Agreement (CRADA) for the purpose of demonstrating and deploying a novel technology for the continuous synthesis and recovery of biodiesel from the transesterification of triglycerides. The focus of the work was the demonstration of a combination Couette reactor and centrifugal separator - an invention of ORNL researchers - that facilitates both product synthesis and recovery from reaction byproducts in the same apparatus. At present, transesterification of triglycerides to produce biodiesel is performed in batch-type reactors with an excess of a chemical catalyst, which is requiredmore » to achieve high reactant conversions in reasonable reaction times (e.g., 1 hour). The need for long reactor residence times requires use of large reactors and ancillary equipment (e.g., feed and product tankage), and correspondingly large facilities, in order to obtain the economy of scale required to make the process economically viable. Hence, the goal of this CRADA was to demonstrate successful, extended operation of a laboratory-scale reactor/separator prototype to process typical industrial reactant materials, and to design, fabricate, and test a production-scale unit for deployment at the biodiesel production site. Because of its ease of operation, rapid attainment of steady state, high mass transfer and phase separation efficiencies, and compact size, a centrifugal contactor was chosen for intensification of the biodiesel production process. The unit was modified to increase the residence time from a few seconds to minutes*. For this application, liquid phases were introduced into the reactor as separate streams. One was composed of the methanol and base catalyst and the other was the soy oil used in the experiments. Following reaction in the mixing zone, the immiscible glycerine and methyl ester products were separated in the high speed rotor and collected from separate ports. Results from laboratory operations showed that the ASTM specification for bound acylglycerides was achieved only at extended reaction times ({approx}25 min) using a single-stage batch contact at elevated temperature and pressure. In the single-pass configuration, the time required gives no throughput advantage over the current batch reaction process. The limitation seems to be the presence of glycerine, which hinders complete conversion because of reversible reactions. Significant improvement in quality was indicated after a second and third passes, where product from the first stage was collected and separated from the glycerine, and further reacted with a minor addition of methanol. Chemical kinetics calculations suggest that five consecutive stages of 2 min residence time would produce better than ASTM specification fuel with no addition of methanol past the first stage. Additional stages may increase the capital investment, but the increase should be offset by reduced operating costs and a factor of 3 higher throughput. Biodiesel, a mixture of methyl esters, is made commercially from the transesterification of oil, often soy oil (see Reaction 1). The kinetics of the transesterification process is rapid; however, multiphase separations after the synthesis of the fuel can be problematic. Therefore, the process is typically run in batch mode. The biodiesel fuel and the glycerine product take several hours to separate. In addition, to push yields to completion, an excess of methoxide catalyst is typically used, which has to be removed from both the biodiesel and the glycerine phase after reaction. Washing steps are often employed to remove free fatty acids, which can lead to undesirable saponification. Standards for biodiesel purity are based either on the removal of contaminants before the oil feedstock is esterified or on the separation of unwanted by-products. Various methods have been examined to enhance either the pretreatment of biodiesel feedstocks or the posttreatment of reaction products, including the use of a cavitation reactor in the process intensification of the homogeneous acid catalysis of transesterification. Centrifugal mixing has been applied to biodiesel production, using the contactor as a low-throughput homogenizer, employing very low flow rates to increase residence times to tens of minutes. In this study, we have combined the reaction of oil and methoxide with the online separation of biodiesel and glycerine into one processing step, using a modified centrifugal contactor. Two distinct phases enter the reactor (reagents), and two distinct phases leave the reactor/separator (products), thus demonstrating the application of process intensification to high-throughput biofuel production. ORNL has been designing, fabricating, and operating centrifugal contactors for the selective extraction of actinide elements for over 25 years.« less
  • The Biofuels Team at The University of North Carolina at Pembroke and North Carolina A&T State University carried out a joint research project aimed at developing an efficient process to produce biodiesel. In this project, the team developed and tested various types of homogeneous and heterogeneous catalysts which could replace the conventionally used soluble potassium hydroxide catalyst which, traditionally, must be separated and disposed of at the end of the process. As a result of this screening, the homogeneous catalyst choline hydroxide was identified as a potential replacement for the traditional catalyst used in this process, potassium hydroxide, due tomore » its decreased corrosiveness and toxicity. A large number of heterogeneous catalysts were produced and tested in order to determine the scaffold, ion type and ion concentration which would produce optimum yield of biodiesel. The catalyst with 12% calcium on Zeolite β was identified as being highly effective and optimal reaction conditions were identified. Furthermore, a packed bed reactor utilizing this type of catalyst was designed, constructed and tested in order to further optimize the process. An economic analysis of the viability of the project showed that the cost of an independent farmer to produce the fuelstock required to produce biodiesel exceeds the cost of petroleum diesel under current conditions and that therefore without incentives, farmers would not be able to benefit economically from producing their own fuel. An educational website on biodiesel production and analysis was produced and a laboratory experiment demonstrating the production of biodiesel was developed and implemented into the Organic Chemistry II laboratory curriculum at UNCP. Five workshops for local farmers and agricultural agents were held in order to inform the broader community about the various fuelstock available, their cultivation and the process and advantages of biodiesel use and production. This project fits both Universities’ goals in the Biofuels Research Initiative, since it uses an alternative fuelstock: namely canola. The outcomes of this project may eventually aid in reducing the state’s consumption of corn and soybean, which are important food crops. The project will also encourage regional farmers to grow alternative crops for biofuel production. The success of this project has contributed towards the development of Robeson County, an economically disadvantaged region. Additionally it should be noted that Robeson County serves a large Native American population. Therefore, training and engaging this minority group in the energy industry was an important accomplishment.« less
  • Prior to disassembly of the CFBR, accumulated tar residue must be removed from the reactor, piping and tubing lines, and the condenser vessels. Based on experience from the CFBR mild gasification tests, lacquer thinner must be pumped through the unit for at least one hour to remove the residual tar. The lacquer thinner wash may be followed by a water wash. The CFBR will be disassembled after the system has been thoroughly flushed out. The following equipment must be disassembled and removed for storage: Superheater; Water supply pump; Coal feed system (hopper, auger, ball feeder, valves); Reactor; Cyclone and finesmore » catch pot; Condensers (water lines, glycol bath, condenser pots, valves); and Gas meter. After the process piping and reactor have been disassembled, the equipment will be inspected for tar residues and flushed again with acetone or lacquer thinner, if necessary. All solvent used for cleaning the system will be collected for recycle or proper disposal. Handling and disposal of the solvent will be properly documented. The equipment will be removed and stored for future use. Equipment contaminated externally with tar (Level 4) will be washed piece by piece with lacquer thinner after disassembly of the PRU. Proper health and safety practices must be followed by the personnel involved in the cleanup operation. Care must be taken to avoid ingestion, inhalation, or prolonged skin contact of the coal tars and lacquer thinner. Equipment contaminated internally by accumulation of residual tar or oil (Level 5) will be flushed section by section with lacquer thinner. The equipment will be washed with solvent both before and after disassembly to ensure that all tar has been removed from the piping, pumps, gas quench condensers, light tar condensers, and drain lines. The coal tars wig be separated from the solvent and incinerated.« less
  • This is a final report for a project funded by the US Department of Agriculture and managed by the US Department of Energy. The Iowa Corn Promotion Board was the principal contracting entity for the grant. The Iowa Corn Promotion Board subcontracted with General Electric, Pacific Northwest National Lab and New Jersey Institute of Technology to conduct research in this project. The Iowa Corn Promotion Board and General Electric provided cost share for the project. The purpose of this diverse collaboration was to integrate both the conversion and the polymer applications into one project and increase the likelihood of success.more » This project has led to additional collaborations among other polymer companies. The goals of the project were to develop a renewable route to isosorbide for commercialization that is economically competitive with all existing production technologies and to develop new applications for isosorbide in various products such as polymers and materials. Under this program a novel process for the production of isosorbide was developed and evaluated. The novel process converts corn based sorbitol into isosorbide using a solid catalyst with integrated water removal and product recovery. In addition the work under this program has identified several novel products based on isosorbide chemistries. These market applications include: epoxy resins, UV stabilizers, plasticizers and polyesters. These market applications have commercial interest within the current polymer industry. This report contains an overview summary of the accomplishments. Six inventions and four patent applications have been written as a result of this project. Additional data will be published in the patent applications. The data developed at New Jersey Institute of Technology was presented at two technical conferences held in June of 2006. Several companies have made inquiries about using this material in their products.« less