Biodiesel quality is important to maintain the integrity of the RFS2 program. Therefore, biodiesel producers have taken all the resources to implement a reliable quality control system. In most of these practices, samples are taken to the quality control lab from the test points of the production line. Important chemical or physical parameters have to be analyzed by skilled chemists or technicians, including samples from transesterification, methanol, glycerin and B100. The analytical results are used to monitor the process and reaction and, if necessary, fine-tunings or corrections are made. Oftentimes, these samples are at elevated temperature and need to be handled cautiously. Commonly there is a delay before analysis results are available for the operator to make the processing decisions (e.g., adjusting the amount of catalyst, changing temperature, pressure, flow rate, etc.), or the end-point determination of the transesterification reaction. Biodiesel producers are looking for a more effective analytical technology with constant monitoring directly at the critical test points (i.e., in-line analysis). 

Fourier Transform Near-Infrared (FT-NIR) spectroscopy is a rapid and nondestructive technique often used for in-process analysis of multiple physical and chemical characteristics in the manufacturing environment. Real-time measurements can be implemented with no sample preparation and the analytical data can be obtained, stored and utilized quickly. However, even though the technology has been available for years, producers are still cautious of having in-line analysis capability due to the complexity of using it. Compared to the bench-top at-line FT-NIR or FTIR analysis, in-line analysis is a significantly complex system to implement and maintain and needs heavy upfront investment commitment. Factors of the sample temperature, flow rate, turbulence, color, contamination, homogeneity, etc., impact the spectral quality and therefore the analyzed results. In order to implement in-line analysis successfully, an experienced in-process spectroscopist is usually required to design the sampling system, build the application algorithms, maintain the hardware and algorithms, trouble-shoot and resolve all the possible application issues.

Historically, in-line analysis has been introduced to the chemical industry for monitoring key parameters in the chemical reaction at well-established chemical processes. With the establishment of the biodiesel industry, producers are reaching out to explore the benefits of in-line analysis capability. As an infrared solutions provider, Eurofins QTA is ready to offer the in-line solution for biodiesel production. 

According to users’ manufacturing processes and test requests, Eurofins QTA will work with potential users to define the best solution of the sampling method and the system configuration. For a normal in-line NIR application, there are three major components including an NIR spectrometer located in a well-protected room or enclosure, required fiber optic cables connecting the NIR spectrometer and the production line, and a flow-through cell or a fiber optic probe to collect NIR spectra from different test points. If it is necessary, a multiplexer coupling with fiber optic cables can be used to extend the application of one NIR system up to 16 test points or reactors (e.g., biodiesel processing line, methanol recycle tank, glycerin purification tank, etc.). 

Due to the complicated sample matrix of the raw materials used in biodiesel production, the NIR algorithms used are usually more difficult to build and maintain than the standard chemical processes. Similar to the off-line NIR service, Eurofins QTA provides the total solution for the in-line users. The users do not have to worry about all the complicated issues. A feasibility study will be performed to make sure it works before the user spends their money on the instrument and other required devices. After the confirmation of the feasibility, QTA patented technology will be used to develop the most rugged in-line algorithms. A simplified user interface allows the plant operator to do the in-line analysis easily. Remote instrument monitoring assures good performance of the spectrometer. 24/7 helpdesk service and remote problem solving capability minimize system downtime. A centralized database allows the users and the managers to access their analyzed data anytime and anywhere via the Internet. Remote method development also allows the user to expand or change their applications without limit. With all the advantages, Eurofins QTA in-line service will become a powerful analytical tool for biodiesel production.

Author: Kangming Ma
President, Eurofins QTA Inc.
513-693-4028
kangmingma@eurofinsus.com