Coal Pyrolysis for High-Quality Tar and Gas in 100 kg Fixed Bed Enhanced with Internals

Abstract

Using internals in kilogram-laboratory fixed bed pyrolysis of coal has been newly reported to greatly upgrade the pyrolysis performance in terms of the yield and quality of the produced tar and pyrolysis gas. This work is devoted to further verifying such a finding through pyrolysis tests in enlarged fixed bed reactors with and without internals at obviously increased coal treatment capacities of about 100 kg of coal per test. The reactors were electrically heated, and the tests were via batchwise operation, while Yilan sub-bituminous coal was used. Comparing the results from reactors without and with the particularly designed internals demonstrated that the use of internals increased the heating to the coal bed by about 20%, while the tar yield was 87.0% of the Gray-King (G-K) tar yield, which was obviously higher than 46.9% of the G-K tar yield from the reactor without internals. In the tar from the internal-enhanced reactor, the content of light tar (boiling point below 360 °C) was about 71 wt %. Raising the furnace temperature from 900 to 1100 °C increased the tar yield from 80.5% to 90.3% of the Gray-King tar yield for the reactor with internals. Parametric studies were performed for coal particle size, heating furnace temperature, and coal moisture content.

Ex‐situ catalytic fast pyrolysis of low‐rank coal over HZSM ‐5 and modified Mg/ HZSM ‐5 catalysts

“…Pyrolysis technology is an emerging technique for producing high‐quality biofuels in liquid, solid, and gaseous phases 4‐9 . The catalytic pyrolysis of coal is an advanced technology applied to cracking the larger tar components into lighter tar components and gases 10‐13 . Previous studies have reported that the tar produced from the catalytic pyrolysis of LRC can be developed into value‐added chemicals, such as benzene, toluene, and xylene (BTX), as well as decalin, tetralin, and naphthalene 14‐18 .…”

“…[4][5][6][7][8][9] The catalytic pyrolysis of coal is an advanced technology applied to cracking the larger tar components into lighter tar components and gases. [10][11][12][13] Previous studies have reported that the tar produced from the catalytic pyrolysis of LRC can be developed into value-added chemicals, such as benzene, toluene, and xylene (BTX), as well as decalin, tetralin, and naphthalene. [14][15][16][17][18] Wang et al examined the effect of the catalyst (NiW/Al 2 O 3 -USY) for cracking high range aromatics into low range aromatics to obtain a diesel product with a large carbon range.…”

In‐Situ Upgrading of Coal Pyrolysis Tar with Steam Catalytic Cracking over Ni/Al2O3 Catalysts

“…Catalytic cracking is a promising way for obtaining high‐quality tar, and catalyst can cause secondary cracking of coal pyrolysis tar, making heavy components cracked into light oil and gas . Liu et al .…”

Enhancement of low‐temperature lignite pyrolysis by recycled carbocoal for high‐quality tar in fixed‐bed reactor

“…Tar fractions were quantified by simulated distillation in GC 7890 (Aglient) according to ASTM D2887‐13 (the Standard Test Method for boiling range distribution of petroleum fractions by gas chromatography). The tar fractions were divided into 2 parts according to two temperature ranges: 50–360 °C; and higher than 360 °C …”