Karrick Process and Low-Temperature Carbonization

This page records a source dossier on low-temperature carbonization (LTC) of coal and oil shale, organized around the Karrick process and its namesake, Lewis Cass Karrick, an engineer associated with the United States Bureau of Mines in the early twentieth century. The dossier sits in the archive's "dossier 10 — Low-temperature carbonization" folder and resolves to the Karrick sub-archive at [source note 3].

Provisional record. The ingested material is a 1932 University of Utah civil-engineering thesis by William Larsen and Clifford Stutz, "Design of Plant for Low Temperature Carbonization of Utah Coal by Karrick Process," reproduced on the source archive Karrick sub-archive. It is a design and cost-estimate document, not a laboratory report, and its performance figures are the authors' own calculations and reported test results rather than independently verified data. Everything below should be read as a description of what this thesis advances, not as a verified technical report.

What the subject is

Low-temperature carbonization is a real, historically documented industrial chemistry: the destructive distillation of coal or oil shale at roughly 450–700 °C, well below the ~900–1100 °C range used in conventional high-temperature coking. The process drives off volatile matter and leaves a solid residue — semi-coke or char — while condensing a liquid fraction (coal tar, "coal oil") and releasing a combustible gas. It was pursued industrially in several countries in the early-to-mid twentieth century as a route to liquid and gaseous fuels from solid feedstock.

The Karrick process is a specific LTC variant attributed to Lewis Cass Karrick. The dossier presents it as a method for extracting liquid fuel and co-products from coal and oil shale at comparatively low temperature.

How it is claimed to work

The mechanism the dossier describes is destructive distillation: coal is heated in the absence (or near-absence) of oxygen so that it does not burn, but instead thermally decomposes. Volatile hydrocarbons and tars are driven off and collected; the residual carbon-rich solid is retained as semi-coke. Because the operating temperature is lower than in conventional coking, the dossier argues that less energy is expended in heating the charge — the basis of its efficiency claim.

The specific Karrick variant is presented as applicable to a broad range of coals and to oil shale, rather than to a narrow grade of feedstock.

Claimed yields and performance

The thesis's central quantitative claims are that LTC of Utah coal carried to less than 18% residual volatile matter yields approximately 30 gallons of crude oil per ton of coal, which on cracking gives 10 gallons of gasoline, 800 cu ft of 1300 Btu gas and 90–100 lb of oil coke; that the smokeless fuel product weighs 60–75% as much as the coal from which it was made; and that 2200 cu ft of 950 Btu gas is produced per ton treated. The thesis also reports a gas analysis table (from Frey and Yant) showing Btu values falling from 1065 at 935 °F to 835 at 1560 °F as steam temperature rises.

These figures are source assertions — the authors' own calculations and reported test runs. The thesis supplies heat-balance calculations and a cost estimate, but no independent replication or third-party verification. The numbers should be attributed to the thesis and not restated as established fact. See Karrick Claims vs. Evidence: The Dossier's Assertions and the Absence of Test Data for the claim-by-claim breakdown.

The historical-suppression narrative

The thesis itself does not advance a suppression narrative; it is a design proposal recommending that a commercial test plant be built at Spring Glen, Utah, and given "a fair trial." The suppressed-inventor framing is a recurring feature of the source archive dossiers generally, not a claim made in this source, and should not be attributed to it.

Evidence status and limitations

• Archive-only evidence. The dossier is a compilation, not a laboratory report. No independent replication is supplied.
• Structured data present. The ingested material contains a gas-analysis table (Table 1, unscrubbed gas, from Industrial & Engineering Chemistry, vol. 19, 1927) and detailed heat-balance and cost-estimate figures. These are reproduced in the source and can be cited directly.
• Scope. The thesis covers process design, heat balance, plant layout and 1932 cost estimates; it does not include patent claim tables or a list of Karrick's assigned patents.
• Unresolved tension. The dossier's efficiency framing sits uneasily with the fact that LTC yields less liquid product per ton than modern routes such as Fischer–Tropsch synthesis or direct coal liquefaction. This tension is surfaced here rather than resolved.
• Historiographic tension. Mainstream histories of coal liquefaction center on Bergius and Fischer–Tropsch rather than Karrick; the dossier's suppressed-inventor framing conflicts with that consensus.

Related work and context

The dossier belongs to the archive's fuels and energy material and follows the recurring Rex pattern of a compilation assembled around a named inventor or process without accompanying independent data — the same shape documented for the Bedini Motor/Generator/Charger, E-Cat (Energy Catalyzer), and Arboform dossiers. Where such dossiers lean on patent documents, the wiki's Patent as Evidence concept applies directly: a patent records a claim, not a demonstration of performance.

Topical parents in this wiki are concepts/fuels, concepts/energy, and concepts/chemistry.

Open questions

1. Is the ingested file a full article or a landing page? The capture-problem probability suggests re-checking the original source.
2. Does the dossier name specific patent numbers assigned to Karrick? If so, each warrants its own entities/usXXXXXXX page.
3. Should the Karrick process be compared directly against Fischer–Tropsch in a dedicated comparison page, or is that beyond the source's scope?