Pushing Plants Harder Reduces Costs More Than We Thought

May 22, 2019 |

By Dennis Zeedyk, Lee Enterprises Consulting

Special to The Digest

 Introduction

If a business has increased production, shouldn’t production costs increase? Over the course of the last four years Glycerin Traders has been fortunate to have a growing business. There is a notable increase in production and sales, but utility costs seem to be staying constant or even decreasing. We believe this is because we have learned to become more efficient and use what we have to its fullest potential.

Background

Glycerin Traders LLC takes in waste raw glycerin from multiple biodiesel plants around the country. It acidulates the raw glycerin to remove the fats for sale to multiple industries. It also strips off methanol and some water that is then further distilled to nearly 100% purity. This is sold back to biodiesel plants as reclaimed methanol for them to use in the transesterification process. The remaining “processed glycerin” is typically 80% glycerin, 1% methanol, 10-12% water, 5-7% salts and remaining MONG (material organic non-glycerin). The flagship operation is based in Defiance, OH. Our company strives to never let a biodiesel plant get tank-locked with raw glycerin so that they can do what they do best, which is to produce quality biodiesel.

Process

When the Defiance plant was purchased in late December 2013, we began operations by just distilling methanol on a 24/5 basis. Soon after operations began, we started the glycerin stripping line to obtain more wet methanol for processing and to have additional reclaimed methanol and processed glycerin for sale. In normal operating conditions, the main glycerin line would run through approximately 2,000 pounds per hour. At about this same time, we moved to 24/7 operations. In February of 2016, we converted the existing biodiesel line to process glycerin as well. Initially, this averaged about 600 pounds per hour. In February of 2018, we converted the feedstock processing line to process glycerin and it averaged about 1,200 pounds per hour. Based on how the feedstock processing line worked, we gained knowledge that enabled us to increase the biodiesel line to an average of 1,000 pounds per hour. The important thing to note is that during this time, we kept the same boiler, same air compressor, same plant manager, etc. We did change out a few pumps and motors, but only to move to larger pumps and larger motors that would facilitate the larger volume we were handling. Naturally, we added some labor to facilitate the greater number of trucks coming and going.

Also during this time, we began to gain a better understanding of how to properly manage our methanol distillation column. While we initially produced 6 truckloads of reclaimed methanol, over time we began to consistently produce 13 truckloads per month. We learned to adjust our pH, blend various degrees of wet methanol to produce a more consistent stream of wet methanol going into the column, and use the best feed pump for this product. We also installed pre-heating of the wet methanol so that the main feed heater was not pushed so hard and ultimately installed a larger reboiler heat exchanger. As you can see in Chart 1, our methanol production almost doubled from 2013 to 2018. Again, no changes were made to our electrical system or boiler other than better management of our boiler water.

Source: Glycerin Trader data

As we began pushing the methanol line harder, we found that our boiler would shut down more frequently. In order to prevent this from happening, we re-piped our steam condensate line, put in better steam traps and put in a new steam feed pump. These things helped to recapture more of the returning hot water (~190 F) and reduce the amount of incoming city water. The incoming cold water requires more natural gas in order to heat it back to steam vs. the returning condensate that is already 190 F. This also helps the boiler tubes last longer as there is less temperature shock. There was no surprise that this helped to cut our water bill. During the process of analyzing the water bill, we saw another cost saving opportunity.

Our city water bill consists of charges for incoming sanitary water and outgoing sewage. Because we had no outgoing sewage meter, the sewage calculation is based on how much sanitary water is used. Our largest water usage is our boiler, chiller, and cooling tower. These use, on average, approximately 12,000 gallons per day. This water doesn’t go back down the drain but rather back into the air. We approached the city and had them install a separate meter for the boiler & cooling tower. Because the city knows that this water does not go back into the sewer, they reduce our water bill to reflect the water used by the boiler and cooling tower that doesn’t go back down into the sewage system.

Results

As you can see in Chart 2, the Defiance plant has gone from producing 14.5 million pounds/year of end-products (reclaimed methanol, fatty acids and processed glycerin) to 29.3 million pounds/year. This was a 95% increase in production. When we began making the changes in our production lines, we anticipated an almost linear increase in electricity and natural gas usage. You can imagine our surprise when we discovered that our monthly bill for natural gas dropped from an average of $17,230 to $13,320 – an 18% decrease. More analysis indicated that our natural gas usage increased by 12%, but gas prices dropped more, so our total annual gas cost decreased by 18%. At the same time, our total cost for electricity increased by 7.1% from 2014 to 2018.

Chart 2. Total Finished Products Produced vs. Utility Costs. The double bar graph above compares the gas and electric bills for each year from 2014 to 2018. The money spent contrasts with the dotted line, representing the increase in production and sales.

Source: Glycerin Trader data

Conclusion

The important takeaways from this article are the following:

  • Putting un-used assets (like our biodiesel and feedstock lines) into production helped us to increase revenue by more than doubling our finished glycerin production. Surprisingly, the boiler and vacuum pump handled the increased production with no problems.
  • Learning to run each line more efficiently (like our methanol line) was a big improvement. Using the same boiler, same column and a new improved feed pump and pre-heater allowed us to increase our methanol production by 50%. We still think there is a possibility of getting 10% more out of the column, but this is not yet proven.
  • Making sure we are pulling as much steam condensate as possible back into our boiler reduces our city water usage. It also helps us keep our natural gas usage to a minimum as we pull hot water back into the boiler, not cold water, while preventing temperature shock to the boiler.

The nature of our company is to continuously increase production and decrease costs. If we can increase production and keep some of our costs the same, we still reduce our costs per unit. We put into production unused assets to help increase our total production and then apply what we learn running these systems over time to maximize the output over time. With valued input from some of our close partners like Harvest Energy, D.A. Dodd, Power Plant Services, Enyart Electric, and Fremont Water, we have been able to push our system harder and operate more efficiently than we ever thought possible. This allows us to take in more raw glycerin from biodiesel plants, produce more finished products, cut costs on a per unit basis, increase revenue and grow as a company.

About the Author: Dennis Zeedyk is the owner of Glycerin Traders, LLC, a glycerin marketing company, and a member of Lee Enterprises Consulting, Inc., the world’s largest and most established bioeconomy consulting group, with over 100 recognized professionals worldwide. Established in 1995, Lee Enterprises Consulting handles all areas of the bioeconomy, including both the established industries such as biodiesel, ethanol, biomass power, biogas/AD, water treatment, and renewable chemicals, and the vast array of emerging technologies.   

Category: Thought Leadership

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