Waste to Energy

Onsite Waste to Energy

This small scale innovative technology is based on staged and separated pyrolysis, gasification and high temperature oxidisation.

The unit is capable of destroying many different types of waste (including medical and plastics, with no pre-treatment), with the option of additional heat recovery, whilst producing only ash/char and a controlled amount of gas (with low emissions). The technology is designed for continuous operation with very little downtime.

The PyroVore is a compact unit (small footprint and minimal noise) which is able to process up to 1,500 tonnes of waste per year and offers significant savings on energy and waste disposal costs and therefore a broad range of potential applications.

PyroVore Features

  • Can process 85% of the European Waste Catalogue of materials, including municipal, industrial, clinical & hazardous wastes
  • Capable of processing up to 250kg/hr, heat output of up to 750 kWth
  • Ash volume is typically 5 to 10% of the input volume
  • 24 hour operation

1. WASTE HOPPER AND COMPACTOR SCREW

Waste is tipped into a reception hopper that feeds the compactor. The waste is densified making it easier to transport, expresses the air from the waste and provides a seal between the atmosphere and the thermal process. This seal ensures that air is not drawn into the process. If it were, combustion would be promoted rather than pyrolysis.

2. PYROLYSER

The first stage of the thermal process is pyrolysis, which is the thermal decomposition of organic material by the action of heat alone. In order to do this the waste is fed along a tube using a screw. The tube is externally heated using gases from later in the process to around 800°C. The heat dries the waste then decomposes organic molecules to form a gas and vapour mixture mostly made up of water, carbon monoxide and dioxide, hydrogen, methane and ethane. The balance of the material is left as a carbon char and ash. Inert materials (such as metal and glass) are merely heated and passed through the tube unaffected.

3. GASIFIER

The gasifier acts as a buffer store for completion of the pyrolysis process. Steam and air are injected into the base of the gasifier to further reduce the volume and carbon content. The waste feed stock is reduced in mass to between 5% and 10% of its original weight.

4. ASH COLLECTION VESSEL

At the end of the tube the inert char and ash is discharged into a refractory-lined vessel, where it is stored before being discharged into ash containers via another screw system.

5. OXIDISER

The gases generated in the pyrolyser and gasifier are fed forward into the oxidiser, which is a refractory-lined combustion vessel. The gases are combusted by mixture with a controlled amount of air in this environment. This is a highly exothermic reaction, which maintains the temperature. The products of this reaction go forward to the pyrolyser, where they are used to heat the waste in the pyrolysis stage.

Case Studies

HMS Ocean

End User: UK MoD
Date: March 2008 - Ongoing
Scope: ST150 Waste to Energy Unit

Overview

  • 2 years of extensive testing was undertaken by Qinetiq and the MoD on a technical demonstrator in Portsmouth
  • Requirement to process 120kg per hour of waste was surpassed
  • Processed a wide range of waste streams from food waste to oil sludges
  • Consistently low emissions recorded
  • Very high availability throughout normal operation
  • Average 7% ash residue
  • The plant is treating over 120kg of waste per hour generated from over 1000 crew on board ship, throughout the World
  • Containment of waste treatment minimises security risk and optimises habitation conditions
  • Ongoing support and unit enhancement

Royal Navy - CVF Aircraft Carriers

Client: Babcock
Date: March 2010 - Ongoing
Scope: ST150 Waste to Energy Unit

Overview

  • 4 off skid mounted ST150s for the UK Royal Navy
  • 2 on each ship
  • Destined for Queen Elizabeth Class Aircraft Carrier
  • 1,000tpa mixed waste stream
  • Onboard 2013

US Army - Forward Aircrafting Bases

Client: US Department of Defence
Date: March 2010 - Ongoing
Scope: ST150 containerised variant

Overview

  • Containerised ST150 for US Army
  • 2 x ISO containers (20x8x8ft) positioned and then bolted together
  • 1000tpa mixed waste
  • Power Generation Capability
  • Air freight capable
  • Minimal infrastructure required

What is Pyrolysis

Pyrolysis is the chemical decomposition of organic (carbon-based) materials through the application of heat.

Pyrolysis occurs in the absence or near absence of oxygen, and it is thus distinct from combustion (burning).

It transforms organic materials into their gaseous components and a solid residue of ash

https://www.britannica.com/science/pyrolysis

Overview

  • To turn waste into energy (where no recycling or reuse is possible) the waste must be processed by thermal equipment.
  • Traditional incineration equipment uses oxygen in the form of air to ‘fuel a fire’ and burn waste.
  • Pyrolysis is a more controlled procedure with the stages being separated and optimised for a more efficient, flexible and cleaner process
  • Heat from produced gas maintains the temperature of the pyrolysis tube during operation, thereby causing less reliance on fossil fuels for thermal process
  • Proven process with several operational units
  • Can process a wide range of materials, including commercial, industrial, clinical waste
  • 24 hour operation
  • Supports a decentralised energy strategy