Custom Circulation Heater Enhances Biodiesel Plant's Productivity

Circulation Heater

The Challenge
Biodiesel production plants produce clean-burning fuel developed from renewable sources, such as soybean oil, palm oil, canola oil, chicken renderings, port tallow, or beef tallow. Such sources are generally called feedstock. Biodiesel fuel's chemical name is methyl ester, technically a fatty acid. Methyl ester is produced by a chemical process known as transesterification. During transesterification, methanol, a catalyst, and feedstock are combined to produce the biodiesel. A by-product of the reaction is glycerin.

Although the process to produce biodiesel is straightforward, some of the feed-stocks used in commercial biodiesel production facilities exhibited caustic characteristics. Due to this caustic nature of the feedstock, this customer was experiencing process heater failures at a frequency that was unacceptable.  

The Solution
Chromaloxs customer-centered approach to achieve a solid engineered solution involved several steps. First, a complete analysis report of the failed heater was prepared by the engineering department. Second, a sample of the feedstock was evaluated through a controlled test to determine the specific reaction occurring at different temperatures. Third, the engineering team offered a prototype circulation heater to the customer to test the proposed engineering changes in a real world lab the customers biodiesel production facility.  

  1. The updated design employed the use of baffles on the prototype heater. These baffles were used to increase the flow-rate of feedstock, thereby decreasing the caustic reaction.
  2. A decrease in watt density was crucial to mitigate the risk of caustic baking and coking to the heater elements. If the process coked to the heater elements, a drastic reduction in heater life expectancy will occur. Lowering the watt density of the heater elements increases the lifespan of the heater elements by lowering element temperatures. This increases the lifespan of the heater elements and maximizes plant production.
  3. The sheath material was changed from steel to 316 stainless steel to stand up to the caustic nature of the feedstock at operating temperature.

The Advantages
The final result was an improved total heating system that provided a reliable unit despite the severe service. After a successful test period, this solution has become an engineered standard for new facilities. Enhanced production plant productivity level enhanced facility uptime.