Efficiency in feeding change

Azienda agricola CAZZOLA

Customer’s successful application case that with BioBANG has succeeded in significantly reducing of product’s viscosity in the digesters. This reduction allowed the customer to implement a gradual change of daily feeding, reducing the cost and projecting a future plant’s repowering towards biomethane production.

azienda agricola cazzola

Picture 1. “Azienda Agricola Cazzola” farm with biogas plant (on the left)

Description

The “Azienda agricola Cazzola” farm in recent years has given much importance to renewable energies, in particular in the AD sector. In total, 2 biogas plants were built in succession (the oldest in 2010, while the most recent in 2012), both producing 1MW/h of electricity and 500 Nm³ /h of biogas.

The plant on which BioBANG was installed is the most recently built, consisting of a hydrolysis tank, a primary digester and a secondary digester. During construction, the plant was designed to be fed mainly with corn silage and cattle slurry with 30 days of retention time on primary digester.

Before BioBANG installation, the daily feeding was composed by 42 t/d of corn silage and 10 t/d of cattle manure.

PLANT’S DATA
Energy Produced1 MW/h
Biogas produced500 Nm³/h
HRT30 gg
Daily feeding before BioBANGCorn Silage42 t/gg
Cattle Manure10 t/gg
Table. 1. – “Azienda Agricola Cazzola” biogas plant’s data

Customer decided to install BioBANG on the plant to achieved two important goals:

  1. Improve the product viscosity inside the hydrolysis tank in way to load a greater quantity of difficult biomass (more manure, triticale or ryegrass) without having troubles related to floating layers formation on digester’s surface.
  2. After the viscosity improvement, reduce corn silage quantities, gradually replacing it with cheaper biomass (cow manure with litter, triticale, wheat or ryegrass silage) in way to save the total daily feeding cost.

BioBANG was installed in transferring from the primary fermenter to the hydrolysis tank in October 2018. BioBANG currently works 2 m³ /h of product with an Energy Rate of 7.5 kW/m³.

BioBANG DATA
Starting DateOctober 2018
Installation Methodin trasfering from F1 to HT
Flow Rate2 m³/h
Energy Rate7,5 kW/m³
Table 2. – BioBANG – Features and installation method.

Evidence

Video of the first starting of BioBANG on the biogas plant

It’s possible see the differences between the original product and the product after BioBANG’s treatment, already after few minutes from starting BioBANG on the plant.

Product treat with BioBANG show a greater improvement in viscosity and a greater reduction of particles size compared to original sample.

Results:

About 6 months after BioBANG installation, the customer achieved the following results:

1. Viscosity: immediately after starting BioBANG, he noticed a greaterr improvement in the viscosity of the product in all the tanks. After 6 months the viscosity had already decreased by over 50% in the hydrolysis tank and in the primary fermenter and over 25% in the post-fermenter. This clear improvement allowed the customer to obtain the following advantages:

  • Reduce amount of liquid in favor of the solid, thus managing to optimize the daily feeding without increase the plant’s retention times.
  • Optimize the power absorbed and the working times of the mixer and pumping systems. This allowed the customer to reduce the self-consumption of the plant up to 1% of the total.
2. Daily Feeding change: The reduction in viscosity over 50% in the hydrolysis tank has solved the biggest criticality for the plant: not being able to load biomass with a higher fiber content into the digesters, without having troubles with floating layers and superficial crusts.
Graph 1. Daily feeding before and after BioBANG installation.

6 months after the BioBANG installation, customer made a big change in plant’s daily feeding (graph 2). He increase the fiber content keeping the same production, without increasing the dilutions and retention times of the plant and without having problems with crusts and floating layers. Corn silage change from 42 to 16 t/day and the feeding was supplemented with an additional 10 t/d of cattle manure with litter and 20 t/d of ryegrass silage.

Customer saved about 26 t/d of corn silage, the most expensive biomass in his daily feeding. Net of the new costs deriving from the integration of ryegrass silage and manure, the customer saves about € 300 a day compared to the previous costs (data provided directly by the customer) (table 3).

Corn silageCattle manureRyegrass silageDaily cost
t/ggt/ggt/gg€/gg
BEFORE-BioBANG42100€ 2.100,00
AFTER-BioBANG162020€ 1.800,00
SAVING€ 300,00
Table. 3 – Daily feeding cost before and after BioBANG installation.

The benefits obtained from consumption savings of mixers and pumping systems and on the cost of the daily feeding, have also been confirmed by the data that the “Azienda agricola Cazzola” farm has provided regarding the costs to produce 1 Nm³/h of gas before and after BioBANG installation (table 4).

GAS PRODUCTION’S COSTS
Gas produced
(Nm³/h)
Production cost
(€/Nm³ )
Daily
cost
(€/gg)
Annual cost
(€/anno)
BEFORE – BioBANG5000,425.0401.839.600
AFTER – BioBANG0,364.3201.576.800
SAVING0,06720262.800
Table. 4. – Costs incurred to produce 1 Nm3 / h of biogas, before and after BioBANG installation.

The customer observed that, net of self-consumption and plant management costs, after 6 months from the start-up of BioBANG, the cost to produce 1 Nm³/h of gas was reduced from € 0.42 to € 0.36 with a net saving of € 0.06 for Nm³/h.

Taking into account that the plant produces 500 Nm3 / h of biogas, a reduction of € 0.06 for Nm³/h corresponds to € 720 per day that “Azienda Agricola Cazzola” farm save after BioBANG installation.

Conclusion and future goals

The results obtained from the monitoring of the biogas plant shown, that BioBANG has brought as a direct benefit the reduction up to 50% of the viscosity within the hydrolysis tank and the primary fermenter.

Whit this greater improvement in product viscosity the customer was able to:

  • Optimize the power and working time of mixers and pumping systems to reduce the plant’s daily self-consumption.
  • Simplify the plant’s management. The customer was able to increase the use of biomass with a higher fiber content, without having complications deriving from increase in viscosity and formation of floating layers or surface crusts.
  • Gradually reduce the daily feeding cost, using biomass rich in fiber to start a first start-up towards a future repowering of the plant from biogas to biomethane production.

Thanks to the results achieved, net of the fixed costs (CAPEX) and variables (OPEX) of BioBANG (see table 5).

BioBANG Costs
TypeCost (€)TOTAL
CAPEXBioBANG Purchasing BioBANG
Shipping
Installation
189.900
2.000
2.000
232.000 €
OPEXSelf-Consumption
Ordinary management
37.000
2.000
Table. 5 – Fixed and operating costs for BioBANG

“Azienda Agricola Cazzola” farm has expected a return on BioBANG investment costs already within one year after the installation (table 6).

NET GAIN AFTER ONE YEAR
NET SAVINGCAPEX/OPEXNET GAIN
262.800232.00030.800
Tab. 6 – guadagno netto dell’azienda Cazzola, dopo il primo anno di operatività di BioBANG

In conclusion, the results obtained with BioBANG, are part of a customer’s project to optimize the plant in terms of management and costs. In fact, the customer has set the following goals in the medium / long term:

  • MEDIUM TERM: Reduce again the daily amount of corn silage, increasing the amounts of cattle manure with litter
  • LONG TERM: install another BioBANG unit also on the other biogas plant of the farm in order to start a total conversion from biogas to biomethane production.

The Long term goal that the “Azienda Agricola Cazzola” farm has set is to remove corn silage, to completely replace it with more economic manure and agricultural crops in view of the next incentives for biomethane, in way to have a complete conversion of its plants from biogas to biomethane production.

Do you want to book the free test with our mobile unit directly at your facility?

Are you a Manufacturer of AD plants who is planning a plant powered by waste and difficult biomass, or are you a owner of a biogas plant that wants to reduce the costs of its daily feeding by replacing corn with cheaper biomass also in view of a future conversion to biomethane?

From the free test you will can observe the results and the potential of BioBANG treatment directly on your biomass.

 
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