Rendall process outline
The Rendall process is totally different from both conventional and emerging oil shale retorting processes. It presents a radical new approach to conversion of oil shale kerogen to refinery-ready synthetic crude oil product:
- scalable to large stream capacities
There are three main steps in the Rendall process:
- Maximising oil production from oil shale kerogen in a single reactor, at about 450°C and 42 bar:
- simultaneous pyrolysis of the kerogen, and
- hydrogenation of its breakdown products by tetralin (a potent hydrogen-donor, generated by hydro-treating of naphthalene in a mid-distillate recycle from the distillation section).
Supercritical solvent extraction
Separation of the heavy product oil coating from the spent shale residue, using a toluene-rich light-distillate recycle from the distillation section, to ensure that:
- oil production is maximised, and
- the shale residue leaves the process as a dry, oil-free, water-insoluble solid material for disposal as a benign mine fill, or further processing for recovery of mineral by-products &/or manufacture of Portland cement.
Separation of the combined streams of mid-light hydrocarbons (ex-kerogen conversion) and toluene + heavy oils (ex-solvent extraction) into:
- synthetic crude oil product for despatch to the market, plus
- internal process feed and solvent recycles, and
- methane gas (for power generation, process heat and hydrogen production).