A major potato processor dramatically increased biogas production from its anaerobic wastewater treatment facility by adding Novozymes BG Max®   

Benefits

  • 112% increase in biogas yield per kg of COD removed
  • 86% increase in biogas production overall
  • Enhanced COD removal in the anaerobic system
  • Reduction of floating grease build-up in the anaerobic treatment unit 

Background 
The plant had an anaerobic internal circulation (IC) reactor that converted starchy wastewater to biogas. The plant operators wanted to increase COD degradation in the IC and increase biogas production for additional cost savings. 
  
Application 
The facility produces french fries and potato flake used in a variety of food products. It uses a multi-stage wastewater treatment process which includes both anaerobic and aerobic treatment units to treat 2,800 m3/day (0.74 MGD) of starchy wastewater (4,000 mg/L COD). The IC is the source of biogas production. The biogas generated in the IC is utilized as fuel for the boiler system. The customer and Novozymes teamed up to trial BG Max®  to demonstrate its ability to improve biogas production and lower treatment costs. 
  
Results 
Over a 90-day period, BG Max® delivered an 86% increase in biogas production. The enhanced conversion of organic compounds to biogas was evident by a 112% increase in biogas yield from 0.34 to 0.72 m3/kg (5.5 to 11.6 ft3/lb.) COD removed. This also contributed to decreased loading to the aerobic system, thereby reducing the energy demand. An additional side benefit of this application was a reduction in floating grease build-up in the anaerobic system.

 

 

Without BG Max®

With BG Max®

Biogas production (m3/day)

2,389

4,435

Biogas yield (m3/kg COD)

0.34

0.72

COD removal (%)

38

53

Table 1. Productivity diagram

Fig. 1. Biogas production and COD removal increased with the use of Novozymes BG Max® 3000

Fig. 2. Biogas yield increased 112% during the different trial stages.  

    
Conclusion 
The addition of BG Max® to the anaerobic treatment system of a potato processor increased biogas production and improved treatment efficiency. This resulted in: 
Offset natural gas purchases 
Decreased energy demand 
Lowered overall cost of treatment 
Improved sustainability 
 

News story: BG max Improve