Decarbonisation Technology - November 2024 Issue

to increase recycling rates and plastic circularity. For example, the EU has introduced a ban on member states exporting hazardous or hard- to-recycle plastic to non-OECD countries. It has also set stringent waste-reduction targets, which include increasing its plastic recycling rate to 55% by 2030 and sending less than 10% of municipal solid waste (MSW) to landfill by 2030. The gasification opportunity Gasification is an established process – one that Shell has been pioneering for almost 70 years by combining continual research with real-world learnings from gasification projects around the world. Today, thanks to new pre-conversion technologies developed by Shell and its strategic partners, gasification can convert a wide range of low-value, mixed municipal, biomass, and unsorted plastic waste and residues into a valuable syngas. Syngas is a versatile intermediate feedstock that can be used instead of virgin hydrocarbons to produce fuels, electricity, chemicals, and plastic (see Figure 1 ). Crucially, adapting production sites with existing gasification units to process low-value mixed municipal, biomass, or unsorted plastic waste is an efficient and cost-effective approach (compared to greenfield projects) that provides companies with two key opportunities. First, they can leverage low-value biomass waste, such as sustainable wood residues

Bulk plastic waste

Biomass, agricultural residues, waste

Woody biomass

Liquefaction

Fast pyrolysis

Torrefaction

Liquids feeding system

Solids feeding system

Gasication

Low-carbon-intensity, circular syngas

At the same time, the world has a growing waste problem, generating more than 2 billion tonnes of solid waste annually – a total expected to grow by more than 80% by 2050. Figure 2 Shell and its strategic partners have developed a range of pre-conversion technologies suitable for a wide range of waste streams In particular, plastic waste makes up as much as 12% of global solid waste, the majority of which ends up in landfill or incineration, or is mismanaged. Indeed, less than 10% of global plastic waste is recycled each year, leading to greater efforts “ Adapting production sites with existing gasification units to process low-value mixed municipal, biomass, or unsorted plastic waste is an efficient and cost-effective approach ”

Gasication

Bulk plastic waste Plentiful supply Produces syngas Product exibility

Utilises remaining plastic waste Requires extensive sorting and high-purity waste streams

Pyrolysis, depolymerisation and dissolution Requires intensive sorting and high-purity feed Small proportion of current plastic waste streams Mechanical Established recycling paths Requires extensive sorting Lack of product exibility

Deploymerisation Pyrolysis Gasication

Mechanical Dissolution

Figure 3 Gasification can be used to complement other plastic-recycling methods to produce syngas that is equivalent to virgin feedstock