Bubbling fluidized bed combustion of Syncrude coke

Abstract

Trials on the burning of Syncrude coke (solid residue of Athabasca oil sands after processing at the Syncrude plant, Fort McMurray, Alberta), were performed in an atmospheric fluidized bed combustion (AFBC) pilot plant (bed area 0.155 m2 ). The coke is high in sulphur, up to 7% by mass, and reduction of SO2 emissions is therefore necessary. An Athabasca limestone was used as the SO2 sorbent. The conditions of the trials were mean coke particle diam. 0.26 mm; mean limestone particle diam. 0.34 - 0.94 mm; fluidizing velocity 0.8 - 1.3 m/s; excess air, up to 7%; recycle ratio (fraction of cyclone catch recycled) 0 - 0.83; Ca/S mole ratio 1.7 - 2.9; bed temperature 966 - 1105 ° C. The high bed temperatures were needed to achieve stable burning and reasonable combustion efficiency. The combustion efficiency as measured by carbon burnup was 77 - 97%. At these temperature levels, sulphur capture was influenced most strongly by bed temperature. The capture was unexpectedly good up to 1050 ° C then fell sharply, practically to zero above 1100 ° C. It is concluded that Syncrude coke can be burned by AFBC with acceptable combustion efficiency and sulphur capture at bed temperatures of 950-1050 ° C and fluidizing velocities up to 1.3 m/s. Syncrude coke is high in vanadium, 0.18% by mass, as well as in sulphur. The results indicate that the vanadium is fixed in the ash and is not selectively concentrated in any of the product streams.

Process integration of a Ca-looping carbon capture process in a cement plant

“…The operating conditions inside the carbonator and the calciner are also favourable to the capture of SO 2 (Anthony et al, 1987). It is assumed that all SO 2 generated by combustion in the calciner is captured by CaO and the negative effects of sulphation on the maximum carbonation degree is taken into account in the carbonator model (Romano, 2012).…”

Analysis of a Process for Capturing the CO2 Resulting from the Precalcination of Limestone in a Cement Plant

“…The air feed is subjected to two chemical reactions: total coke combustion and 90% SO 2 retention by means of CaO sulfation. (SO 2 retention has been shown to be effective up to 1050 °C, according to Anthony et al 10 ) A recycled stream from the precalciner is fed into the combustor together with fuel and air. The combustor outlet in the cyclone is separated into gas and solid streams.…”

Process for Capturing CO2 Arising from the Calcination of the CaCO3 Used in Cement Manufacture

“…There is also a need to minimize heat requirements (Figure 3) and pollutant emissions, both of which increase with increasing combustion temperatures. In particular, SO2 retention has been shown to be effective only up to 1050 °C according to Anthony et al (15). There is, therefore, a trade off between the temperature difference between the combustion and precalcination reactor and the solid circulation rate required to achieve the required heat transfer between the reactors.…”