By Boris Kamchev
 
Environmental Lubricants Manufacturing produced bio-based greases by using microwaves earlier this month, demonstrating a technology created by University of Northern Iowa researchers and an Iowa-based industrial microwave company.
 
“It’s a revolutionary process that is going to change and make our industry more competitive,” Lou Honary, owner of Grundy Center, Iowa based bio-lubes and greases producer ELM, told Lube Report. Honary is professor and director of the university’s National Ag-Based Lubricant Center.
 
In collaboration with the center and AMtek Microwaves, an industrial microwave manufacturing plant in Cedar Rapids, Iowa, ELM served as a demonstration site for processing bio-based grease using microwave heating.
 
“The whole idea of using microwave in our soybean-based grease production came because of the fire that happened in our facilities. The heat transfer oil was the main reason for the accident that destroyed the whole plant in 2007,” Honary said.
 
Along with the grease manufacturing facility, the fire destroyed ELM’s entire lubricants production as well. After the disaster, the company management decided to look into alternative methods for heating. “The microwave appeared to be the most logical way. We did some testing in the laboratory, and we were pleasantly surprised that the microwaves are more suitable to water than to petroleum oils. The polarity of the materials has much to do with how the microwave actually works,” he observed, adding that vegetable oils absorb the microwave energy even better than water, and much faster than mineral petroleum products.
 
The first attempts to make samples took place in NABL’s laboratory. “Together with my colleague, Wes James, I worked on small batches of soybean and other vegetable oils. We learned that it works after we heated the [vegetable] oil in the microwave and added various thickeners, and succeeded in making some greases,” said Honary. More experiments were performed at AMTek using larger industrial microwave systems, he added.
 
The university applied for a patent for the grease microwave heating technology in 2009. “After we tried soybean oil and even a mixture of petroleum and soybean oil, we realized that this technology has huge possibilities and advantages if it’s used for bio-based grease manufacturing,” he asserted.
 
NABL agreed with AMtek to implement the innovation, and AMtek’s engineers joined the production staff of ELM to build the first production quantity 800-gallon stainless steel reactor, according to Honary.
 
“We started to collaborate with AMtek, and they received licenses from the university to pursue the technology for processing chemicals, including greases. The results are spectacular – we’ve made seven batches of grease so far,” said Alan Burges, ELM’s manager of operations. “The process is much faster, a lot safer and it seems like we are getting more complete reactions.”
 
“I think that we have a revolutionary process in our hands,” Honary said. “The benefits are that the microwave unit can be installed anywhere in the plant, and you can bring the waves using wave guides anywhere. The footprint is very small: no hot oil and hot spots, or oil reservoirs with burners.” The wave guides are isolated tubes that transmit the microwave energy from the source to the grease reactor. “The energy goes directly to the product because there is no need to convert electric to thermal energy and to heat liquids that will transfer it using pipes.”
 
The system is economically efficient and has safety benefits as well. “We estimated that microwave heating needs only a third of the time and energy, compared to the conventional method. The safety aspects are evident: as soon as you shut the heating off the energy input stops immediately, eliminating other sources of heat loss and danger,” Honary observed, adding that this technology is very advanced and that the system is designed to prevent microwaves from escaping. “There are even instruments that can measure wave leakage in the installation.
 
“People have general of misconceptions about microwaves. We’ve seen a grant rejection because the reviewer thought that microwaves would cause arcs in the metal reactor.” Honary explained that microwaves can be applied to steel tanks if designed properly to balance the microwave energy with the mass that is being heated.
 
“The challenge for us is to make a few more of these grease batches, to build the experiential data needed to be shared with the rest of the industry,” he concluded. “A system that can reduce production time and save energy at the same time should have a positive impact on the competitiveness of our industry.”