Overcoming a Capacity Bottleneck
Nitta Gelatin Canada, Inc., Canada’s only producer of natural, unflavored pork skin gelatin, turned a manufacturing capacity bottleneck into an opportunity to reduce energy costs.
The company had been ramping up production at its Toronto plant to meet a growing demand for its high quality gelatin products, which function as gelling agents, binders, emulsifiers, or thickeners in a wide-variety of products. Gelatin has numerous and varied uses in many food products, including marshmallows, gummy candy, ice cream and luncheon meats. Other common uses include gelatin capsules for pharmaceuticals, emulsions for moisturizing lotions and other cosmetics, and even coatings for the production of photographic paper.
Production at the Toronto plant was limited by the capacity of the existing evaporators that concentrated the gelatin product. As with any manufacturing bottleneck, the limited capacity of this process prevented the expansion of the overall plant output.
“Because of the high cost of installing an additional evaporator, we tried to think outside of the box to find an alternative solution,” said Nitta plant manager John Walker. “We wanted to find a solution that was both cost-effective and environmentally sensitive.”
Thinking Outside of the Box
Nitta Gelatin implemented a state-of-the-art membrane filtration system that allowed it to avoid the capital cost of installing a new evaporator. “We determined that by preconcentrating the product with membrane filtration prior to the evaporator process, we could remove a significant amount of moisture mechanically, and thereby increase our production capacity without building an additional evaporator,” Walker explained.
“By investing in a membrane filtration system, we would not only overcome our production bottleneck, but we would also improve the plant’s profitability by improving the energy efficiency of our production process.”
Nitta Gelatin turned to Koch Membrane Systems (KMS) of Wilmington, Mass., the technology and market leader for protein separation by membranes. For more than 30 years, Koch Membrane Systems has been developing and manufacturing new membranes for concentrating, purifying and clarifying gelatin, egg whites, soy proteins, enzymes and lysine.
In 2004, the Toronto plant commissioned a KMS membrane system designed to remove 20 percent of the moisture in the gelatinous fluid. The system contains 64 FLUID SYSTEMS® TFC® - SR®3 low pressure, selective rejection nanofiltration elements. These spiral wound elements utilize a proprietary polyamide thin-film composite membrane.
The application at Nitta Gelatin required the use of nanofiltration elements because the process fluid contained a high percentage of low molecular weight proteins. The KMS SR3 membranes have a molecular weight cut-off of 200 daltons and provide a significantly higher yield of proteins, as compared to ultrafiltration membranes. The SR3 elements retain more than 99.5 percent of low molecular weight proteins.
In addition to high yield, the SR3 also has the benefit of operating under low pressure (200 – 400 psi), requiring less energy than other nanofiltration elements.
“One of the most important reasons that we choose the SR3 elements is their ability to sustain high process temperatures,” said Walker. The process fluids pass through the membrane system at temperatures as high as 60 degrees Celsius, well above the upper limit of the operating temperature range for most other elements.
The high temperature serves two purposes. First, it helps keep the process fluid from gelling and fouling the membranes and other equipment. Second, the process fluid remains at a high temperature to preserve heat energy as the concentrate fluid moves on to the evaporator process. To further retain heat energy, the permeate water removed during the membrane moisture removal process is run through a heat exchanger prior to disposal in order to retain and reuse the thermal energy.
Reduced Capital Expenditures and Operating Costs
Carl Hoffman is the market manager for the food, dairy and beverage business unit at Koch Membrane Systems, and has worked closely with Nitta Gelatin in solving the bottleneck problem. According to Carl, “Use of the SR-3 nanofiltration system has proven to be a cost-effective solution for Nitta Gelatin by significantly reducing their energy expense while producing a cleaner gelatin product. The SR-3 membrane elements have exceeded our life cycle expectations while operating at elevated temperatures.”
John Walker agrees with Carl. “Despite the gelatinous material and the high temperature operating conditions, the SR3 elements have performed to my expectations and exceeded the product claims,” said Walker. “We have been able to maintain high performance and long membrane life, averaging a year or more, by performing a clean-in-place procedure every second day.”
Not only did Nitta Gelatin avoid the capital expenditure of a new evaporator, it achieved ongoing reductions in energy costs. The KMS membrane system consumes three to four times less energy to take out an amount of moisture equivalent to that removed in the evaporator process.
“We have removed the bottleneck and increased the plant’s production volume by 20 percent, plus we have significantly reduced our energy consumption per unit of production,” said Walker. “The improved energy efficiency of our process is important due to the high and unpredictable cost of the natural gas we burn to produce steam for our evaporators.”
The nanofiltration preconcentration process has proved so successful that, in the summer of 2006, a nanofiltration system using KMS SR3 membranes was commissioned at Nitta Gelatin’s brand-new, state-of-the-art facility in Fayetteville, North Carolina.