You need JavaScript to view this

Mineral matter behaviour in low-NOx combustion. A laboratory study

Technical Report:

Abstract

A bench-scale facility was built for the representative testing of the behaviour of coal minerals in low-NOx (staged) combustion of pulverized coal. The heart of the system is a staged laminar-flow gas burner with a primary central fuel-rich burner, surrounded by an oxygen-rich secondary burner. Refractory plates are used to test the deposition behaviour of the coal minerals in the near-burner zone. The form of the ash resulting from the minerals was also assessed. Bituminous coals were used, one rich in pyrite and one rich in calcite, both slag inducing minerals. A silica-rich coal was primarily tested for the form of the fly ash. Close to the burner the unburnt coal forms a protective layer on the probe surface, preventing deposition of the minerals. At greater distances the secondary air burns away this carbon layer so that the minerals can reach the probe. The calcite breaks up into fragments which are too small to impact. The pyrite particles gave a tenacious slag since they deposit and stick in molten form and solidify by oxidation. It is thus concluded that it is in the combustion air rather than the primary flow that gives rise to burner slagging with pyrite. More specific  More>>
Publication Date:
Jul 01, 1992
Product Type:
Technical Report
Report Number:
ECN-RX-92-035
Reference Number:
SCA: 014000; PA: ECN-92:0E0787; SN: 93000917859
Resource Relation:
Other Information: DN: Paper presented at the EPRI conference on the Effects of Coal Quality on Power Plants, San Diego, California, USA, 25-27 August 1992; PBD: Jul 1992
Subject:
01 COAL, LIGNITE, AND PEAT; COAL FINES; STAGED COMBUSTION; BITUMINOUS COAL; PYRITE; CALCITE; CLAYS; FLY ASH; SPHERICAL CONFIGURATION; CHARS; DEPOSITION; BENCH-SCALE EXPERIMENTS; EXPERIMENTAL DATA; TEST FACILITIES; PYROLYSIS; SLAGS; PARTICULATES; NITROGEN OXIDES; 014000; COMBUSTION
OSTI ID:
10110577
Research Organizations:
Netherlands Energy Research Foundation (ECN), Petten (Netherlands)
Country of Origin:
Netherlands
Language:
English
Other Identifying Numbers:
Other: ON: DE93752678; TRN: NL92E0787
Availability:
OSTI; NTIS (US Sales Only)
Submitting Site:
ECN
Size:
23 p.
Announcement Date:
Jun 30, 2005

Technical Report:

Citation Formats

Ten Brink, H M, Eenkhoorn, S, and Hamburg, G. Mineral matter behaviour in low-NOx combustion. A laboratory study. Netherlands: N. p., 1992. Web.
Ten Brink, H M, Eenkhoorn, S, & Hamburg, G. Mineral matter behaviour in low-NOx combustion. A laboratory study. Netherlands.
Ten Brink, H M, Eenkhoorn, S, and Hamburg, G. 1992. "Mineral matter behaviour in low-NOx combustion. A laboratory study." Netherlands.
@misc{etde_10110577,
title = {Mineral matter behaviour in low-NOx combustion. A laboratory study}
author = {Ten Brink, H M, Eenkhoorn, S, and Hamburg, G}
abstractNote = {A bench-scale facility was built for the representative testing of the behaviour of coal minerals in low-NOx (staged) combustion of pulverized coal. The heart of the system is a staged laminar-flow gas burner with a primary central fuel-rich burner, surrounded by an oxygen-rich secondary burner. Refractory plates are used to test the deposition behaviour of the coal minerals in the near-burner zone. The form of the ash resulting from the minerals was also assessed. Bituminous coals were used, one rich in pyrite and one rich in calcite, both slag inducing minerals. A silica-rich coal was primarily tested for the form of the fly ash. Close to the burner the unburnt coal forms a protective layer on the probe surface, preventing deposition of the minerals. At greater distances the secondary air burns away this carbon layer so that the minerals can reach the probe. The calcite breaks up into fragments which are too small to impact. The pyrite particles gave a tenacious slag since they deposit and stick in molten form and solidify by oxidation. It is thus concluded that it is in the combustion air rather than the primary flow that gives rise to burner slagging with pyrite. More specific guidelines for slag prevention will come from a future model that will use the test data obtained here combined with the proper burner-aerodynamics. It is concluded from the present work that it is not the difference in oxygen environment that causes the observed differences in form between fly ash from staged and unstaged boilers. Fine silica dust, which gives a reflective deposit in boilers, is a relic of the fine silica included in the coal. These inclusions do not agglomerate because of the high melting point and are liberated from the coal char at carbon burnt-out when the char disintegrates. Staging does not influence this process. 3 figs., 2 tabs., 13 refs.}
place = {Netherlands}
year = {1992}
month = {Jul}
}