Hungry Caterpillar
10 automatically-fed two-stage systems for AD research
The Hungry Caterpillar is designed for high throughput, continuous, two-stage anaerobic digestion research. Ten automatically-fed 1 L reactors each feed into a second-stage reactor, allowing you to compare feedstocks, OLR/retention time, additives, and more across ten parallel systems. Effluent flows from the first stage into the second, so you can investigate the different stages of AD.
- Continuous operation.
- Fully automatic feeding.
- Gas production automatically measured.
- 10 parallel two-stage systems
- Software and PLC included
- 2 automatic feeding rates
- ~1x week feedstock top up
Run multi-stage AD in your lab
The Hungry Caterpillar enables research into VFA control, microbial dynamics, nutrient recovery, or new pathways such as hydrogen production. With ten 2nd stage reactors, the Hungry Caterpillar provides advanced experimental configurability, and control.
Fully automatic feeding.
- Reduce daily handling — each feeder typically requires refilling only once per week.
- Replicate the feeding schedule of real AD plants.
- Program feeding intervals and organic loading rate directly from the control system.
- Two independent feeders let you compare different loading strategies simultaneously.
Key features
Ten two-stage systems
Ten 1 L first-stage reactors connect to ten second-stage reactors, supplied at 2 L as standard, for parallel multi-stage AD research.
Two automatic feeding rates
Set two independent feeding rates to test different organic loading rates and retention times.
Temperature control
Maintain your chosen reactor temperature with programmable heater jackets.
Continuous operation
Feed automatically and transfer effluent from the first stage into the second for long-term experiments.
Mixing and Agitation
Dedicated mixer motors mix the reactor contents, while agitators homogenise the incoming feed.
Sampling ports
Access reactor contents during your experiments to investigate the different stages of AD.
Automatic gas measurement
Measure and record gas production using the included gas flow meter and data logger.
Software and PLC included
Configure feeding through the PLC control panel and use the included software to work with your data.
Inside the Hungry Caterpillar
10x 1L Reactors
The robust stainless steel reactors provide the non-reactive environment for anaerobic digestion. Enquire for different reactor volumes.
10x 2nd Stage Reactors
Stainless steel 2nd stage reactors come in a range of sizes.
250ml Effluent Bottle
The easily removable effluent bottle collects the excess digestate to avoid pressure build ups and spillages.
Automatic Feeder Syringe
The patented feeder syringe feeds the reactor at your programmed rate. It prevents backflow from the reactor and a full syringe feeds for about a week.
Mixer motor
Each reactor comes with a 20 rpm motor which constantly mixes the inside of the reactors.
Heater Jacket
The custom fit heater jackets maintain a consistent, programmable temperature inside the reactor.
Agitator Motor
To ensure homogenous feed, the agitator mixes the feedstock coming up from the feeding syringe.
15-cell Gas Flow Meter
Custom 15-cell gas flow meter measures gas production in ~10ml increments (subject to calibration).
Technical Specification
| Feeding type | Automatic |
|---|---|
| Reactors, 1st stage | 10 |
| Reactors, 2nd stage | 10 |
| Number of automatic feeders | 2 |
| Reactor volume | 1 / 2 / 5 / 10 L |
| Gas flow meter | 15-cell |
| Effluent bottle | 0.25 L |
| Temperature control | Ambient – 85°C |
| Agitators and mixers | Agitators 900 rpm, mixers 20 rpm |
| Mixer motor | 24V DC |
|---|---|
| Heater jacket | 110V AC, 85W |
| PLC control screen | 110V AC |
| Data logger | Arduino, 9V DC |
Optional extras
- Larger reactor sizes (enquire)
- Pressure valve for higher pressures inside reactor
- pH probe