30+% boost of average daily biogas production at Wisconsin dairy farm

Overview

  • >30%: Average daily production boost of biogas after introducing Drylet's BioReact AD
  • 60%: Methane ratio remains unchanged and steady
  • $470: Daily value of additional electricity sold to the utility
  • $2,086: Average daily new gross income opportunity from renewable natural gas sold to the pipeline (on top of historically generated electricity)

THE SITE
Dallmann's East River Dairy is host to a 1.7-million gallon capacity digester designed by DVO, Inc. The manure from its 2,400 cows generates electricity, bedding, fertilizer, and heat. The operation also incorporates an ammonia/nitrogen recovery system after the digester, which helps to clean the biogas. The resulting methane generates enough electricity to power 500 homes -- it is sold to the utility.

THE TECHNOLOGY
Dryletʼs innovative technology draws from material science and microbiology. Its BioReact AD product is comprised of carefully selected beneficial microbes embedded inside non-toxic particles made of an engineered porous media substrate. The particles are approximately 200-600 µm in size. They protect the microbes, allowing them to thrive and replicate fast so they can be effectively integrated into microbial ecosystems.

HOW IT WORKS
Anaerobic digestion is a three-step process:
1.Hydrolysis: Long-chain molecules from bacteria, such as carbohydrates, proteins and fats, are being degraded into sugars, amino acids and long-chain fatty acids respectively.
2.Acidogenesis and acetogenesis: The products of hydrolysis are converted into short-chain fatty acids (e.g. acetate), CO2 and H2.
3.Methanogenesis: Archaea (methanogens) convert SCFA, H2 and CO2 into methane. The lysis, or breakdown, of the bacterial cell wall is necessary before the longchain molecules contained inside the cell can be broken down. Drylet's innovative technology enables the enhanced degradation of undigested solid waste (hydrolysis), promoting a reduction in biosolids and an increase in the generation of biogas.

THE PROCESS
BioReact AD was dosed in the methane digester at a daily rate of 13 lb over 61 days. With a consistent influent (cow manure) in both composition and quantity over the whole period and no operational changes, the effect of BioReact AD clearly registered as a stable increase of biogas production with unchanged gas composition at 60% methane.

 

THE IMPACT ON REVENUE

The demonstration resulted in an over 30% average boost of biogas generation. At the site, methane from biogas is used to generate electricity. Most of it is sold to the utility. It was calculated that electricity from the additional methane generated through using Bio React AD represents a net value of about $470 per day.

Additionally, significant solids reduction resulted in cleaned-up sludge lines, reducing operating and maintenance costs.