33 PDH
Virtual Digester Operator School

In this module, you’ll learn how to both optimize the performance of a digester and perhaps more importantly, how to avoid digester failures

This module consistently ranks as the most valuable by our past students. For those of you who haven’t had math in a while, we’ll start slowly talking about how to keep track of units when doing your calculations, imperial/metric conversions, how to monitor overloads, converting biogas into energy values, and business considerations like determining the value of heat and electricity compared to renewable natural gas. Finally, we’ll walk you through how to determine whether you should accept a truckload of material that shows up at your door.  Will the material make money or will it cost you more to deal with the water because there’s so little biogas potential in its contents?

Although emphasis is often and rightly placed on the biological aspects of digester operation, it is important to remember that an AD system is primarily a MECHANICAL SYSTEM. Understanding how to make sure the mechanical systems are operating optimally is critical.  We’ll cover receiving material, conveyance, storage and pre-treatment; then mixing, heating and gas handling; finally, we’ll take you through digestate separation, and handling the separated liquids and solids.

Some of our expert operators think we should spend a day and half on hydraulics because as operators, you’re handling hydraulic issues every day. But we’ve condensed the essentials of pumps, mixers, monitoring systems and more into a fraction of that time to raise your knowledge quickly and effectively.

We’re fortunate that our friends at UW-Oshkosh have one of the best labs in the biogas industry and that they are a dedicated teaching institution. As such, you’ll learn directly from the experts who run the lab to understand how to use lab work to help digester performance and to trouble shoot issues.  Plus, we’ll help you learn how to apply the results from the lab tests your order and what it all actually means.

Odor management and prevention starts and ends with good digester operations. We’ll show you which operations in particular most relate to odor issues so you know what to focus on first. This module is often interlaced with story time—anecdotes of what went wrong at some digesters and how those issues could have been prevented or management more effectively. If you’d like to dive into this issue more, the ABC has a day long course called “Odor Management at Anaerobic Digestion Facilities” which is available on-demand, anytime online (https://americanbiogascouncil.org/odor-management-at-anaerobic-digestion-facilities/)

The safety module usually lasts a full day. We’ve offered to past students to try to reduce the time we spend on this important topic, but universally, we’re told, all this time is needed.  We’ll cover H2S dangers, lockout/tagout, operating in confined spaces, rescue procedures, hot work, flammable and explosive properties, hazard communications, process safety and security, MSDSes and more.

For producing renewable natural gas or electricity, operating gas cleanup equipment is essential.  This module covers H2S removal, biogas upgrading to RNG/pipeline quality, engines, and managing both gas and electrical interconnections with the local utility.

In this module, we want to position you to maximize the revenue you can generate from digestate. We’ll cover the mechanics of different liquid/solid separation systems, nutrient recovery technologies and how to get your digestate certified so your customers know they can trust the safety and agronomic value of the digestate they’re receiving.

For anyone handling waste, vectors are a common issue. We’ll cover advice for brids, flies, rodents, varmints, and the control and housekeeping necessary for their prevention.

This module covers what most digester operators need to disclose regularly to stay in compliance.  We’ll also cover the reporting needed to participate in lucrative programs like the federal Renewable Fuel Standard and California’s Low Carbon Fuel Standard.

In the biogas industry, the operators that have a reputation for high performing digesters are always in demand. We’ll cover the qualities that digester owners look for from their best compensated operators.

This module is both an application of the content that you’ve learned in the previous modules and preparation for the tour this afternoon.  It’s often loud on site, so we’ll cover some of the technical details when it’s easier to hear to enhance the value of your experience on site.