Karrick Process Dossier (Fourth Capture): Low-Temperature Carbonization at the source archive

This page records a fourth capture of the source dossier on the karrick-process and Low-Temperature Carbonization (LTC) (LTC). It is a variant-provenance record, not a new body of evidence. The underlying subject — Lewis Cass Karrick's low-temperature carbonization work at the US Bureau of Mines, as described in a 1932 University of Utah thesis by Larsen and Stutz — is already covered in depth by three earlier ingestions of the same dossier, and this capture adds no substantive material beyond a distinct archive path and a different image set.

Readers looking for the mechanism, chemistry, claimed yields and the evidence assessment should start with the earlier source articles and the comparison page listed under Related captures below. This page exists primarily so that the provenance of this particular capture is traceable.

What this capture is

The source is a source page hosted under a CoalMiningLibrary/karrick/ path on the source archive. That path differs from the locations recorded for the three prior Karrick ingestions, which indicates the archive hosts multiple Karrick pages rather than one canonical document. The wiki therefore treats all of these captures as variants of a single dossier, not as independent corroboration of one another. Two captures of the same underlying text do not constitute two sources of evidence.

The audit metadata for this capture describes a text-and-logo capture: the only image URL recorded is 0logo.gif, the archive's own logo. The page's substantive content is textual, including a gas-analysis table (Table 1) and heat-balance calculations, though the source notes that several referenced figures and drawings are not included in the capture. The logo is decorative and is not reproduced here.

Subject in brief

The Karrick process is a low-temperature carbonization variant attributed to Lewis Cass Karrick, developed during his tenure at the US Bureau of Mines. Where conventional high-temperature coking operates near 900–1100 °C, LTC heats coal at roughly 450–700 °C, driving off volatiles through Destructive Distillation and leaving a solid char. The dossier's claims concern the resulting product streams — Semi-Coke as the solid residue, Coal Tar and other condensable volatiles, and gaseous and liquid fuels — and the assertion that LTC can extract more usable fuel per ton of coal than high-temperature coking while accepting a wider range of coal grades. Those claims, and the absence of supporting test data in the dossier, are examined on Karrick Claims vs. Evidence: The Dossier's Assertions and the Absence of Test Data; they are not re-argued here.

Evidence status of this capture

The capture carries a moderate capture-problem probability (0.51) — roughly a coin-flip that the captured text is incomplete or malformed. This is a provenance and quality flag about the capture, not a scientific judgment about the process. It means the article above should be read with the caveat that the underlying page may have been only partially retrieved, and that any absence of detail in this record may reflect the capture rather than the source.

The source itself 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, which reports design calculations, a gas-analysis table (Table 1, from Industrial & Engineering Chemistry, vol. 19, 1927), and yield figures such as 30 gal crude oil per ton and 2200 cu ft of 950 Btu gas per ton. These are reported measurements and design estimates from a student thesis, not independent replication of the Karrick process. As with the earlier captures, the material documents claims and reported figures rather than demonstrated commercial performance — the general caveat captured by Patent as Evidence applies to any patent or press material reproduced in the dossier.

Structured data

The capture contains no SQL DDL, schema definition, API signature or configuration block. There is nothing to preserve verbatim beyond the provenance identifiers below.

Related captures

• Karrick Process and Low-Temperature Carbonization: A source Dossier (Provisional Record) — Karrick Process and Low-Temperature Carbonization (first ingestion, provisional record)
• Karrick Process Dossier (Second Ingestion): Low-Temperature Carbonization at the source archive — Karrick Process Dossier (second ingestion)
• Karrick Process Dossier (Third Capture): Low-Temperature Carbonization at the source archive — Karrick Process Dossier (third capture)
• Karrick Claims vs. Evidence: The Dossier's Assertions and the Absence of Test Data — the claims-versus-evidence assessment shared by all captures
• Karrick Dossier Figures: Captioned Schematics and Uncaptioned Images — the image set recorded for the Karrick dossier
• KLTCC (Abbreviation in the Karrick Dossier Image Set) and NTU Retort (Rifle-Coal Retort Design in the Karrick Dossier) — named items appearing in the Karrick dossier image set

Open questions

1. Should multiple captures of the same dossier be merged into a single source article with a variant-provenance note, rather than proliferating near-duplicate source pages?
2. Is the CoalMiningLibrary path a distinct archive section worth a single shared provenance note across all Karrick captures?
3. Given the 0.51 capture-problem probability, is a re-capture attempt warranted before treating this record as final?