Corrosion-Resistant Gasification of Municipal Solid Waste for Fuel Production

Converting municipal solid waste (MSW) into liquid fuels through gasification is chemically feasible but fails at commercial scale because the heterogeneous waste stream produces corrosive byproducts — primarily nitric acid and chlorine compounds — that destroy downstream piping and catalysts within months. Fulcrum BioEnergy spent over $1 billion and 15 years attempting this, and the identical failure (nitric acid corrosion of downstream equipment) occurred at Air Products' Tees Valley plant eight years earlier. The feedstock variability of real MSW makes it fundamentally harder to control than the homogeneous inputs used in lab demonstrations.

Sustainable aviation fuel (SAF) demand is projected to grow 10–20x by 2040 to meet airline decarbonization mandates, but current production covers less than 0.1% of global jet fuel demand. Municipal solid waste is one of the most abundant potential feedstocks — approximately 2 billion tonnes are generated globally each year, most of it landfilled or incinerated. If MSW gasification could work reliably, it would simultaneously address waste disposal and clean fuel production. Airlines including United, Cathay Pacific, and Japan Airlines invested directly in Fulcrum, signaling real demand.

Fulcrum BioEnergy built a $200 million gasification plant near Reno, Nevada that began operations in 2022. It shipped a small quantity of synthetic crude before shutting down for repairs when corrosive byproducts damaged equipment. The plant restarted and failed again due to the same gasification system issues. Air Products' Tees Valley project in the UK experienced the identical problem years earlier — the startup was "plagued by the unexpected creation of nitric acid, which ate through the facility's equipment." The root cause in both cases was the same: real municipal waste contains nitrogen, chlorine, and sulfur compounds in varying concentrations that produce acidic gases during high-temperature gasification. Lab-scale and pilot-scale tests use pre-sorted, relatively homogeneous feedstocks that don't capture this variability. Existing gas-cleaning technologies (scrubbers, filters) are designed for more predictable industrial gas streams and can't handle the compositional variation of MSW-derived syngas.

Progress requires either (1) corrosion-resistant materials and coatings that can withstand the acidic, chlorinated syngas environment at gasification temperatures, or (2) robust real-time sensing and adaptive gas-cleaning systems that can handle the compositional variability of MSW-derived syngas, or (3) preprocessing approaches that can cost-effectively remove nitrogen and chlorine-bearing materials from the waste stream before gasification. Adjacent fields with relevant solutions include geothermal energy (corrosion-resistant well materials for hot acidic fluids), chemical processing (adaptive scrubber systems), and waste sorting (AI-driven robotic sorting for contaminant removal).

A student team could investigate one of several scoped approaches: (1) characterize the range of corrosive species produced by gasifying different MSW compositions using small-scale reactor experiments, mapping feedstock variability to corrosion risk; (2) test candidate corrosion-resistant coatings or linings under simulated MSW syngas conditions; (3) design a low-cost inline sensor system for detecting corrosive species in syngas in real time, enabling adaptive gas cleaning. Relevant disciplines include materials science, chemical engineering, environmental engineering, and sensor design.