Project Synopsis

Provide a process engineering review of a biodiesel plant design followed by on-site process troubleshooting and startup support.

Project Summary


The client owns a new 30 million gal/yr nameplate capacity biodiesel plant in the U.S.  Process Engineering Associates, LLC (PROCESS) was contracted to provide process engineering support and plant startup assistance.

The plant was originally built in 2007, but was only partially completed.  The original plant design consisted of three main process units: (1) Biodiesel – core transesterification process, methyl ester purification, glycerin purification, and methanol recovery; (2) Pretreatment – chemical refining, and physical refining; and (3) the Fatty Acid Stripper.  The plant was designed to maximize flexibility for processing a wide range of feed stocks including refined and unrefined vegetable oils (soybean and canola), animal fats, and used cooking oils.


Prior to PROCESS starting the project, only the core biodiesel process unit had been fully completed, started up, and briefly run on refined canola oil.  Long term economics were unfavorable for processing refined vegetable oils.  When PROCESS became involved, the plant had installed a scaled back and modified Pretreatment unit (chemical refining only), that was designed to enable processing of some lower cost feedstocks (certain animal fats) through the Biodiesel unit, and had partially installed a new biodiesel production technology: enzymatic esterification.  The long term plan was to integrate the modified Pretreatment unit, and the Biodiesel unit into the new enzymatic esterification process.  This would be a radical process change as enzyme esterification would completely replace the “traditional” transesterification reaction chemistry.  The plant was attempting to start up on choice white grease feedstock.

Specific project tasks completed by PROCESS included the following:

  • Independent Process Review  The plant requested an independent evaluation of the modified Pretreatment unit.  PROCESS reviewed the actual physical modifications that had been made to the original design, the process chemistry, and the operational procedures; and provided confirmation that the process modifications were appropriate for their short term objective of processing certain animal fats to produce methyl ester (biodiesel).
  • Startup Assistance for the Pretreatment and Biodiesel Units  The plant was understaffed and lacked sufficient operations and expertise in process engineering support. The plant also suffered from frequent equipment breakdowns, inadequate heat tracing and insulation of critical piping resulting in line pluggage, and unfavorable process chemistry issues such as excessive soap generation. PROCESS provided day-to-day operations support, assisted in troubleshooting  process and controls issues, and implementing process improvements to help the plant achieve longer continuous run times and produce in spec product.

Industry Type

  • Biofuels Manufacturing

Utilized Skills

  • Process design review
  • Process troubleshooting
  • Plant operations support

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