Development of a Biodiesel Pilot Plant and Research Facility

Grant #: 98-06
Principal Investigator: Jon H. Van Gerpen
Organization: Iowa State University
Participants: Jeff Rothermel, Kirk Menges
Technical Area: Renewable Energy

Background and Significance:
Biodiesel is an alternative diesel fuel for diesel engines. It is produced by chemically reacting a vegetable oil or animal fat with an alcohol. The resulting compound is called an alkyl monoester and has properties that allow it to provide equal performance and better emissions compared to conventional diesel fuel. Biodiesel is renewable, non-toxic, and biodegradable.

Over the past nine years, considerable research has been conducted to investigate the properties of biodiesel, and its performance in engines, and to provide the supporting data needed to satisfy the Environmental Protection Agency’s Fuels and Fuel Additives Registration program. The Iowa Energy Center has supported some of this work, along with the National Biodiesel Board, state soybean promotion boards, and many other private and governmental groups. Virtually all of this work has focused on the use of methyl soyate, the ester produced by reacting soybean oil with methanol. The result of all the research on methyl soyate is that biodiesel is now fairly well understood by manufacturers and fleet managers. The greatest current needs in the biodiesel commercialization area are to demonstrate existing technologies to potential plant operators and fuel consumers, and to develop new technologies that could reduce the cost and improve the value of biodiesel.

This pilot plant uses commercial processes is a valuable tool for educating the general public about alternative fuels. It can also be used to showcase the technology for potential plant owners and to train plant operators. The plant is being used to scale up laboratory processes to test their viability before a full-scale plant is built. The plant can also be used to produce fuel for fleet demonstration projects.

Researchers are particularly interested in processes that will reduce the cost of biodiesel. The current use of food-grade soybean oil as the feedstock for biodiesel has caused the price for the fuel to be $2.50/gallon which is too high for a significant market to develop without government mandates.

Inedible oil from spoiled soybeans, waste oils and greases from restaurants and food service facilities, beef, pork, and chicken fat from rendering plants are all possible sources of lower cost feedstocks. The important differences between these low-cost fats and oils and food-grade soybean oil are high free fatty acid levels and higher saturation. The high free fatty acid levels will cause more waste if traditional alkaline catalysts are used to produce biodiesel. However, acid-based catalyst routes are available. Higher saturation can actually provide a superior quality biodiesel (higher cetane number and lower emissions) although the pour point of the fuel is higher. Biodiesel from animal fat-based yellow grease can be produced for as little as $1.50/gallon. These problems can be overcome with additional development work. We are currently developing processes to utilize these feedstocks and will use the pilot plant to evaluate the commercial viability of the processes.

Project Objectives:
The objective of this project has been to construct a biodiesel pilot plant that can produce biodiesel using a variety of feedstocks and several different production processes. The facility is scaled to allow production of biodiesel to support demonstration projects both within the university and beyond. The project is taking place in three phases. The first phase, which is now completed, has developed the pilot plant to process waste oils and refined oils into biodiesel using both acid and alkaline catalysts. This phase has focused on process development and quality control. The second phase, which is also essentially complete, extended the pilot plant to being able to process oilseeds to produce refined oils suitable for processing to biodiesel. The second phase also included the addition of a diesel-powered electric generator that uses 100% biodiesel to produce a portion of the heat and electricity used at the BECON facility.

The third phase of the project will add the capability to recover excess methanol and to refine the glycerin co-product. We are also adding the capability to use either batch or continuous-flow processes.

Summary of Work to Date:
The construction portions of the first two phases of the project are complete. The capabilities of the pilot plant to improve process yield and extend the range of feedstock variability continues. The limits of current production techniques for handling high free fatty acid feedstocks have been identified and new techniques established. Preliminary work shows the problem of high acid values can be solved in a relatively simple way.