Final Report: Zero Waste Biodiesel: Using Glycerin and Biomass to Create Renewable Energy

EPA Grant Number: SU833526
Title: Zero Waste Biodiesel: Using Glycerin and Biomass to Create Renewable Energy
Investigators: Norbeck, Joseph , Brady, Sean , Leung, Gregory , Phan, Quoc-Hung , Salam, Christopher , Tam, Kawai
Institution: University of California - Riverside , University of California - Davis
EPA Project Officer: Nolt-Helms, Cynthia
Phase: I
Project Period: August 31, 2007 through March 31, 2008
Project Amount: $10,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2007) RFA Text |  Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Energy , P3 Awards , Sustainability


All over the country, large processing developments of biodiesel are taking root and beginning to produce a synthetic, yet biodegradable and environmentally friendly fuel. Additionally, for at least the last 60 years, small, unregulated biodiesel production has been going on in towns and farming communities. With the advent of alternative fuels, biodiesel is becoming extremely popular since vehicle modification is unnecessary. However, the creation of biodiesel from vegetable oil by the chemical process of trans-esterification generates a glycerin waste product, which has flooded the market for commercial glycerin in the United States. This waste stream needs to be explored for industrial and personal use as a new energy source.

The biodiesel synthesis method that we use is a trans-esterification process, which combines an alcohol, as a thinning agent, with vegetable oil to create a viscous combustible liquid. The end result of the biodiesel production is the creation of glycerin as a byproduct. Although glycerin does have its commercial uses, even the current modest biodiesel production has outstripped the US glycerin demand. Initially this was not of significant concern, as glycerin does have its industrial uses. However as biodiesel production has increased so has the amount of glycerin produced, far exceeding what the market could bear, leaving huge amounts of largely worthless glycerin in the manufacturers' hands. Developing an innovative product and process for making a new product from the glycerin waste is our focus.

In looking for a process to absorb this excess glycerin, we have combined waste glycerin with waste biomass such as sawdust or waste paper, to produce combustible pellets as an alternative to coal energy plants, as a new type of refuse derived fuel (RDF), and/or possibly a home heating pellet. This product would be valuable because the raw materials are low in cost and the product is fully carbon neutral. And since these pellets will require components of little or no value, they will ultimately be converting waste biomass to an economically viable energy source.

Experiments were performed to systematically test the effects of a number of parameters including glycerin to biomass ratios and types of biomass materials. With the pellets created, a bomb calorimeter was used to help optimize the product in defined ranges with respect to the available energy content. The energy content was then compared to other sources of energies such as coal and RDFs. The energy content of our pellets were found to be on par with the low end energy content of coal and RDFs. The next step in this proposal is to show that the emissions from this new energy source are less than that of coal or other petroleum energy sources. By comparing the emission from our pellets versus other combustible material such as coal and RDFs we will be able to establish that our pellet will prove to be beneficial to the environment, and the economy, and demonstrate sustainability.

By providing the data to show that our waste glycerin pellets are environmentally friendly and economical our project will be able to provide results that will eliminate the main fault that comes from producing biodiesel. By eliminating the main byproduct, biodiesel production will grow which in turn will lead the United States to be less reliant on overseas oil and fossil fuels. Our ultimate goal will be reached, which is to provide awareness of the biodiesel community and creating a sustainable product that is environmentally friendly from beginning to end of its life cycle process.

Summary/Accomplishments (Outputs/Outcomes):

The procedure for the creation of pellets is fairly mundane, however crucial, in order to create a standard and repeatable process. The pellets biomass material are mixed by weight ratio, and blended to a consistent particulate size. The glycerin to biomass ratio by weight is mixed together. The mixture is transferred into the mold and the ends are then pressed by a vice grip or some other agent that can deliver a significant amount of force to form the pellet.

Key observations were made during the process in creating a sample pellet. When combusting a pellet, it is best that the substance has dried to a point where the water content of the object is negligible. This concern arises from two aspects. The first aspect is making sure that the raw materials have a low water content. The second aspect is making sure that the pellets are not exposed to ambient air. Ambient air contains a relatively small amount of moisture but due to glycerin being hydrophilic in nature; i.e. the strong tendency to absorb water over time, the pellets will absorb moisture from the surrounding air. This moisture content could act as a partial heat sink, and thereby limiting the amount of energy available for conversion to electricity.

Experiments were conducted with a calorimeter bomb to obtain the energy content of the glycerin pellets and the results show that the energy content from our waste glycerin pellets are around the low end energy content produced by coal and RDFs. Our results also show that the energy content of the pellets produce roughtly 0.7 kJ per gram more than traditional biomass. We do not see that this will be a major problem considering that with the additive of glycerin the pellets burn roughly 3 times longer than biomass. Our results also show that as the glycerin to biomass ratio increases the energy content increases also which agrees with the theoretically calculated energy contents.

Due to the observations that were observed the most appropriate place for this product to be used is as a substitute for coal in existing energy plants, wastewater treatment plants where RDFs are used, and/or possible home heating unit such as the types that are popular in Europe.


In conclusion, our project focuses on creating a sustainable, feasible, and environmentally friendly product that will increase the awareness of biodiesel to alleviate the reliance that is place on fossil fuels. In order to accomplish this, our group has developed a pellet made of waste materials and glycerin byproduct from the biodiesel process. This is done by utilizing waste materials that can be found on an every day basis with an additive (glycerin) to create an alternative combustible fuel that can be used in existing processes found in coal fire plants and RDF waste facility plants. Our results show that the energy content is on par with low end range of the amount of energy produced from coal and RDFs. Our pellets are still a significant venture due to the life cycle of the creating of the pellets. Since the pellet is created from waste materials, our product will be economically viable and sustainable. Our project has the potential to solidify the establishment for biodiesel as an alternative fuel and produce an alternative source of combustible energy with its byproduct.

Proposed Phase II Objectives and Strategies:

In order to verify that the life cycle of our product is environmentally friendly from beginning to end, our group proposes to analyze the amount of the chemical and physical emissions produced from combusting our waste glycerin pellet. By analyzing the amount of the chemical and physical emission produced from our pellet being combusted, a comparison will be made against burning coal, the main source of energy, presently. If the emission produced is lower or significantly lower compared to coal, our pellet will prove to be even more beneficial towards to the environment than coal while producing roughly the same amount of energy as coal. To analyze the chemical and physical emission produced from combusting the pellets, equipment will be purchased to provide readings on the following chemicals: NO, NO2, O2, HC, SO2, and CO. The emission will also be collected in a tedlar bag for analysis in a gas chromatograph meter for potential air borne carcinogens. Another sample will be taken to be analyzed for particulate matter that is given off from burning the pellet, too. By analyzing for these chemical and physical emissions, the data will be extrapolated to show the emissions given off on a time basis, for example, “x” amount of NO2 per year by unit of ppmv.

Supplemental Keywords:

Biodiesel, glycerin, biomass, renewable energy, alternative fuel, waste product, pollution prevention, life-cycle analysis, clean technologies, waste reduction, waste minimization, environmentally conscious manufacturing, emissions,, RFA, Scientific Discipline, Sustainable Industry/Business, POLLUTION PREVENTION, Environmental Chemistry, Sustainable Environment, Energy, Technology for Sustainable Environment, sustainable development, environmental sustainability, alternative materials, biomass, energy efficiency, energy technology, alternative fuel, biodiesel fuel, alternative energy source