Breaking New Ground with Glycerin
Glycerin has an amazing history as an oleochemical. It is Alfred Nobel’s work with glycerin and his discovery of nitroglycerin (and associated guilt) that led to the Nobel Prize. Glycerin was originally produced through a hydrolysis process in which a triglyceride molecule was broken down into a glycerin molecule and fatty acid molecules. Today most glycerin is derived from biodiesel production.
Whole Energy became interested in glycerin in 2006 as we were planning the development of a vertically integrated, regional biodiesel company with feedstock collection and marketing. Although we decided to narrow our focus on marketing and distribution of biodiesel, we also maintained a growing interest in the applications and uses of glycerin, and in ways to process glycerin.
As a chemical, glycerin has potential for being a feedstock for all kinds of secondary synthetic chemicals. To accomplish this task, however, glycerin must be available at a sufficient quality and price to support these chemical processes. We hired consultants to evaluate the various pathways to make chemicals and discovered that processes that start with very high purity glycerin already existed.
New Glycerin Refinery Opens
In 2010, we were able to secure partial funding from the state of Washington to develop a glycerin refinery. Our research had indicated that we would need to take an intermediate step in processing glycerin and targeted a purity of 95 percent and low levels of salt, methanol and water. Our funding was in place in mid-2012 and we completed construction in 2013. The plant is located in Mt. Vernon, Wash.
The basis of Whole Energy’s glycerin process is to distill off water and methanol and then allow salts and other residuals from biodiesel production to separate from the glycerin. The resulting glycerin has a purity of 92 to 98 percent and a dark color. At some point, we intend to add polishing to reduce contaminants that affect the color and odor of the glycerin that is produced.
The most common method to address the color of glycerin is filtration with activated carbon. This method is widely used for bioproducts, but those products typically have much higher value. Since glycerin is a relatively low-value material, carbon treatment must be done in a way that allows for either regeneration or the ability to use a grade of carbon that is less expensive but still effective.
We successfully commissioned our plant early this year and we are now working hard to align regional supply of crude glycerin with market demands for the purified product. Although the plant can process 300 tons per week, we are only processing roughly 40 tons a week at this time. The facility has both rail and truck delivery capabilities for both incoming and outgoing product. We have calibrated meters for product delivery.
One challenge we are facing is the impact that low corn values (less than 10 cents per pound) have on the largest volume segment of the glycerin market, which is animal feed. Feed facilities use glycerin to help reduce losses of feed as dust. So glycerin serves a dual purpose. To date, feed-related buyers of glycerin have not wanted to pay more for glycerin than they pay for the underlying feed.
Because glycerin is not a renewable fuel, it is not negatively impacted by shifts in federal regulatory incentives under the IRS or U.S. EPA. There is potential for production to be a stable and reliable source of income for both the plant and the suppliers of our raw material. Many producers see the potential for increased revenue and reduced carbon intensity as a result of our efforts.
Glycerin values have changed significantly over the past few years. Glycerin used to cost around $1 a pound when made as a dedicated product. Today, the highest-quality glycerin sells for around 50 cents per pound. In addition, numerous lower grades are available from 10 to 30 cents per pound. Whole Energy wants to serve the lower-grade markets for midterm and establish new applications for this grade of glycerin.
Hence, we are currently underutilizing our production capacity and are working to define new markets for glycerin concurrently. Those include gas scrubbing, the processing of biodiesel raw materials, an inexpensive thermal fluid, drying and material handling of secondary agricultural commodities including feed and nutrients (where intellectual property is in development), and as a blend stock for propylene or ethylene glycol.
Glycerin for Gas Scrubbing
Gas scrubbing using glycerin has been an area of interest for us for several years. About three years ago, Whole Energy decided to grow our marketing and distribution capability to include renewable natural gas. We quickly became aware of the importance and expense of gas scrubbing. If this could be done cost-effectively at a smaller scale, we could flare a lot less natural gas.
The purpose of gas scrubbing is to remove contaminants present in gas produced from the ground or from an anaerobic digestion process. The contaminants from a digester are different from those from geological gas reservoirs. In either case, the value of the gas is enhanced if the gas can be purified. Glycerin has high selective adsorption of most of the contaminants to be removed.
A column is used to expose the gas to be purified to the maximum surface area possible. The glycerin adsorbs contaminants like oxides of nitrogen (NOx), hydrogen sulfide (H2S), and carbon dioxide, and allows purified methane to be used in an economically beneficial manner. A scrubbing system also needs to release the adsorbed contaminants into the air with the appropriate air permit.
In 2012, Whole Energy demonstrated in a lab setting that glycerin performed well in removing contaminants from biogas. We applied for patent protection in early 2013 and then for funding from the California Energy Commission to construct a pilot facility.
We were happy to learn that our project would be funded and have since focused on making the demo a success.
Using results from our pilot, we will be ready to refine the technology so that we can produce quality gas for a much lower capital and operating cost. Our simpler gas scrubbing methodology has the potential to increase the practical utilization of both renewable and geological sources of natural gas that are currently being underutilized or flared.
The market value of the various grades of glycerin will increase and thereby provide a growing source of coproduct revenue to the biodiesel industry. We appreciate the opportunity to share what we are learning about glycerin while we continue developing the methods of low-cost purification and new applications for glycerin.
Author: Atul Deshmane
President, Whole Energy