Standard: API 4009


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This study has been sponsored by the American Petroleum Institute, to provide an up-to-date appraisal of the engineering and economic factors associated with the removal of sulfur oxides from stack gases. Major emphasis is placed upon the reduction of emissions from large oil or coal burning electrical power stations of the order of 800-MW capacity. The sulfur dioxide pollution potential from all power generation sources has been estimated at 13-million tons per year in 1966 (approximately 46 percent of the emission potential from all sources in the U.S.A., Ref.4-6). Attention is also directed to petroleum refining applications (1.6-million tons per year sulfur dioxide generation potential without control) and to lower power generation capacities, i.e., 250 MW, representing either smaller installations or large station operation at high turn-down ratios. Similarly, the application to new stations designed for power levels in the range of 1600 MW is included in this study.

The first objective of this program was to select from a wide variety of proposed gas treatment systems a limited number of processes which might be adapted for demonstration field use for large scale pilot evaluations. At the completion of the above task, it was proposed to examine in detail the cost factors for those processes whose technical feasibility had been demonstrated on a scale sufficiently large to permit reasonable extrapolation to large field installation. Some proprietary processes were not included since no operating data were available for independent analysis, e.g., Wellman-Lard Process.

The second and main program objective was to provide up-to-date information on capital and operating costs for specific flue gas treatment systems so that the public, private industry, and governmental agencies responsible for the control of sulfur oxide emissions could (a) assess the economic impact and (b) compare the flue gas cleaning concept to other methods suggested for reduction of sulfur oxides pollution. The latter techniques include fuel desulfurization before combustion (Ref. 7-9), fuel substitution (gas and nuclear fuels), atmospheric dilution via tall stacks and/or operation in isolated geographic areas (Ref. 10,11, 11a), and advanced combustion technique (Ref. 12,13).

It is emphasized that sulfur oxides removal from stacks represents only one of several approaches that might prove to be a practical control measure. Several U.S. groups are engaged in or are sponsoring research activities in these other areas; E.G., American Petroleum Institute, Bituminous Coal Research Institute, U.S. Bureau of Mines, the National Centre for Air Pollution Control.

A Preliminary survey suggested that even the more advanced processes might not be acceptable control measures at the present time. Insufficient field trails on a scale large enough to permit safe extrapolation to full sized power plants presented a major problem in system appraisal. Other factors defining acceptability or non-acceptability are discussed in a later section of this report.

It was decided that only those processes with a history of pilot plant operations would be given detailed study. If a process were developed principally for a foreign marked in which power costs, raw materials or sulfur by-product did not relate to the U.S. economy or technology it was also excluded from detailed review. Finally, when two or more processes were essentially the same in basic technical features, only one of the group was selected. The above constraints were applied, however, only after a detailed information survey involving library research, review of preliminary or unpublished experimental data and discussions and correspondence with key investigatory groups in the sulfur removal area.

Organization: American Petroleum Institute
Document Number: api 4009
Publish Date: 1968-08-01
Page Count: 75
Available Languages: EN
DOD Adopted: NO
ANSI Approved: NO
Most Recent Revision: YES
Current Version: NO
Status: Inactive