Gasification is a high temperature and pressure process that can convert any carbon-based feedstock into a colourless and odourless gas, commonly referred to as synthesis gas or “syngas”. The main high temperature/pressure vessel that contains the process is called a gasifier. Importantly gasification is not combustion (or incineration) as the process uses only a limited amount of oxygen/air, together with steam in a controlled reaction. The produced syngas is primarily made up of four gases, being hydrogen (H2), methane (CH4), carbon monoxide (CO) and carbon dioxide (CO2). These building block gases can then be used in subsequent processes to derive a variety of value adding outputs, including:

• electricity using conventional gas turbines or hydrogen fuel cells;
• hydrogen-based fertilisers, including ammonia and urea;
• synthetic fuels, including diesel and jet fuel.

Gasification as a technology has been employed to produce energy at industrial scale since the early 19th century.  Traditionally coal was used as a cheap feedstock for gasification to produce a syngas.  This syngas, often referred to as “town gas”, was the main source of reticulated network gas supply for many cities prior to mid-century discoveries of natural gas at scale.  In principle, the gasification process can be applied to just about any organic material, including biomass and plastic waste. However, it is only over the last decade or more that using biomass and waste as feedstocks are economically viable, driven by:

• Environmental policies increasing the cost of landfill gate fees / taxes;
• Climate changes policies creating a carbon price and a value for reducing greenhouse gas emissions by diverting waste from landfill; and
• The increasing cost of traditional fossil fuels as feedstocks as an alternative.

Gasification is used to produce hydrogen-rich syngas from sustainable biomass and waste feedstock.
The process can be described as five key steps:

1. Preprocessing by suppliers – biomass and waste is sorted, aggregated, and screened
2. Site delivery and handling – feedstock is delivered to site and mechanically fed into receiving hoppers
3. Gasification – the gasifier thermally converts feedstock into hydrogen-rich syngas
4. Syngas processing & separation – syngas is processed and separated into its component part for use
5. Onsite manufacturing & energy use or on-sold – the manufactured products are sold to offtakers, the hydrogen

The technology is used widely in North America and Europe however other than lab and pilot scale demonstration, is understood by Greenhill Energy as readily used in Australia. Greenhill Energy has confirmed the use of gasification for the waste-to-hydrogen process though lab analysis with CSIRO and HRL, lab scale gasification trials with the University of Adelaide (UoA) and pilot scale testing with a gasification technology provider in Europe. Following successful completion of the technology testing phase, Greenhill Energy now intends to be the first to apply the waste-to-hydrogen technology process at a commercial scale in Australia.