Description

Boiler owners and operators who need additional generating capacity face a number of legal, political,
environmental, economic, and technical challenges. Their key to success requires selection of an
adequately sized low-emission boiler and combustion equipment that can be operated in compliance with
emission standards established by state and federal regulatory agencies.
Recognizing that many issues are involved in making informed selection decisions, the U.S.
Department of Energy (DOE), Office of Industrial Technologies (OIT) sponsored efforts at the Oak
Ridge National Laboratory (ORNL) to develop a guide for use in choosing low-emission boilers and
combustion equipment. To ensure that the guide covers a broad range of technical and regulatory issues
of particular interest to the commercial boiler industry, the guide was developed in cooperation with the
American Boiler Manufacturers Association (ABMA), the Council of Industrial Boiler Owners (CIBO),
and the U.S. Environmental Protection Agency (EPA).
The guide presents topics pertaining to industrial, commercial, and institutional (ICI) boilers. Background
information about various types of commercially available boilers is provided along with discussions
about the fuels that they burn and the emissions that they produce. Also included are discussions
about emissions standards and compliance issues, technical details related to emissions control techniques,
and other important selection considerations. Although information in the guide is primarily
applicable to new ICI boilers, it may also apply to existing boiler installations.
Use of the guide is primarily intended for those involved in either expanding current steam or hot
water generating capacity or developing new capacity. Potential users include owners, operators, plant
managers, and design engineers who are involved in selecting low-emission boilers and combustion
equipment that comply with established emissions requirements. Regulatory authorities who deal with
emission issues and boiler permit applications may also find useful information in the guide.
The guide is organized into topics that address many of the fundamental concerns encountered in
planning a new steam or hot water boiler system. An overview of boilers, fuel feed systems, fuels, and
emissions, which are fundamental considerations in the planning process, is presented in the first part of
the guide. Discussions about firetube, watertube, cast iron, and tubeless boilers that burn fossil or nonfossil
fuels are presented in Chap. 2. Technical terms and emission control techniques introduced in the
overview provide a foundation for following discussions.
Issues pertaining to solid, liquid, and gaseous fuels commonly fired in ICI boilers are presented in
the first part of Chap. 3. Characteristics of fossil and nonfossil fuels are included with emphasis on coal,
oil, natural gas, biomass, and refuse-derived fuels (RDFs). For completeness, other materials such as
heavy residuals from petroleum-cracking processes, coal tar pitch, and pulp mill sludge, which are sometimes
used as boiler fuel, are briefly described. Following the fuel discussions, emphasis shifts to solid
and gaseous emissions that are regulated under the Clean Air Act (CAA). The four principle emissions
from combustion boilers that are regulated under this act include nitrogen oxides (NOx), sulfur dioxide
(SO2), particulate matter (PM), and carbon monoxide (CO). Mechanisms by which these emissions are
formed are briefly described as an aid in understanding the various control techniques for reducing
emissions.