Particle Characteristics in the Reactor and Pelletizing Areas of Carbon Black Production

Abstract

Physical and chemical characteristics of airborne particles (ultrafine, PM₁ , PM _2.5, and PM ₁₀) in reactor and pelletizing areas during carbon black production were measured to assess process related sources of particles in work areas. Results from bagging areas within the same three facilities have been previously published. Particle number and mass concentration measurements were conducted in these work areas and at ambient comparison sites at each of the three carbon black plants. No elevated ultrafine particle number concentrations (UFP, <100 nm) with respect to ambient were determined in the work areas of Plant 1, intermittently elevated concentrations at Plant 2, and permanently elevated concentrations at Plant 3. The intermittently elevated UFP concentrations in the pelletizer and reactor areas of Plant 2 could be related to nearby traffic emissions. The ultrafine particle number concentrations at Plant 2 are comparable to those determined at urban traffic sites. Both work areas of Plant 3 showed elevated UFP concentrations in the pelletizer reactor and areas. In the case of the reactor, which was the only enclosed reactor area investigated among the three facilities, the source of the elevated UFP number concentration was most likely attributable to grease and oil fumes from maintenance activities, a conclusion supported by carbon fractionation analysis. The elevated UFP number concentrations in the pelletizing area in this same plant are related to leaks in the production line, which allowed particulate matter to escape to the surrounding areas. Absolute PM₁₀ mass concentrations were all within normal ambient concentrations except for the pelletizing area in Plant 3, which showed continuous levels above ambient. One additional source contributing to peak level PM₁₀ mass concentrations at Plant 2 was due to wind dispersion from a carbon black spill incident the day prior to measurements. It is concluded from these measurements that no carbon black is released in the reactor and pelletizing areas (as UFP or PM₁₀) from the closed production lines under normal operating conditions.

Keywords:

• carbon analysis
• carbon black
• nanoparticles
• particle number concentrations
• ultrafine

ACKNOWLEDGMENTS

We would like to thank all the companies and workers involved in the measurement campaigns for their welcome help and understanding.

This work was sponsored by the International Carbon Black Association (ICBA).

Notes

^A Difference In/Out mainly due to some peaks during the sampling period.

^B Values uncertain due to possible overload of samplers/inlets.