The report gives results of evaluations of the technical and economic feasibility of candidate control methods which may be capable of 99% removal of total hydrocarbons (HC) emitted from asphalt-saturating and air-blowing operations in asphalt roofing plants, sources of HC emissions for which control technology has not been well characterized. The evaluations were based on information from the literature, theoretical analyses of control systems, and contacts with equipment manufacturers and plant operators. An industry survey showed that thermal incinerators or afterburners are currently the only technique used to control air-blowing emissions. Control techniques for saturator emissions include afterburners, wet scrubbers, high efficiency air filters (HEAF's), and electrostatic precipitators (ESP's). Theoretical analysis of candidate control systems indicated that thermal afterburners, HEAF's and ESP's could remove 99% of the particulates, but it is doubtful that wet scrubbers could achieve 99% removal. Further device evaluation, to identify candidate devices to be recommended for more research and development, showed that afterburners are already well developed and should be capable of 99% removal; but they cost much more than HEAF's and ESP's and fuel availability could constrain widespread use. The report recommends that pilot scale HEAF's and wet ESP's be tested on an air-blowing source.

Prepared by Midwest Research Institute, Kansas City, Missouri, under contract no. 68-02-1324, task 35, ROAP no. 21AFA-106, program element 1AB015. Tables. Includes appendices. Includes bibliographical references.