Petroleum Coke: Industry, Health, and Environmental Issues

November 18, 2016

Petroleum Coke: Industry, Health, and Environmental Issues

North American crude oil and natural gas production has

increased significantly over the past decade, primarily as a

result of new or improved technologies (e.g., hydraulic

fracturing, directional drilling, in situ injection) used on

unconventional resources (e.g., shale, tight sands, coalbed

methane, oil sands). The increase in production has

occasioned a range of societal transformations, both

economic and otherwise, including the potential for new

environmental impacts.

Petcoke impurities (i.e., the non-elemental carbonaceous

substances) include some residual hydrocarbons left over

from processing (referred to as volatiles), as well as

elemental forms of nitrogen, sulfur, nickel, vanadium, and

other heavy metals. These impurities exist as a hardened

residuum captured within coke’s carbon matrix. Table 1

provides an observed range of petcoke’s main properties.

One area of concern arises from the production and use of

petroleum coke, or petcoke. Petcoke is a co-product of

several processes used during petroleum refining to upgrade

“residuum” into gasoline and middle distillate-range fuels.

Residuum (or resid) is the substance that remains after

refineries initially distill heavy crude oils. Nearly half of

U.S. petroleum refineries (56 in 2015, as reported by the

U.S. Energy Information Administration [EIA]) have the

capacity to process heavy crude oils. Many refiners

installed technologies over the past decade to take

advantage of lower priced heavy crude oils from Saudi

Arabia, Venezuela, and the Canadian oil sands.

Composition

In 2013, issues related to the production of petcoke in

Detroit and Chicago drew national attention. In both

instances, petcoke produced at local refineries was being

stored in large piles prior to sale and shipment. Community

stakeholders raised questions regarding the impacts of

stored petcoke on air quality due to fugitive dust and water

quality due to run-off; the potential for toxic and other

emissions (including carbon dioxide emissions [CO2]) from

petcoke’s combustion as a fuel; and whether these issues

were adequately addressed by local, state, and federal

regulations. As petroleum refining is a nationwide

commercial industry, these questions may arise—or be

revisited—in other locales.

Production and Composition

Petcoke often has economic value as both a heating fuel and

as a raw material in manufacturing. Fuel-grade petcoke can

substitute for coal in power plant boilers, having the

advantage of a higher heating value. Conventional coalfired boilers often blend petcoke with coal, and newer

boiler designs can substitute it entirely. In manufacturing,

petcoke is used in the aluminum, graphite electrode, steel,

and titanium dioxide industries. In 2015, EIA reported that

U.S. refineries produced in excess of 57 million metric tons

(MMT) of petcoke, of which 26% was used as on-site

refinery fuel, 12% was marketed domestically, and 62%

was exported. Top destinations for exports in 2015 included

India (4.7 MMT), Japan (4.3 MMT), and China (3.3 MMT).

Petcoke is composed primarily of carbon. The specific

chemical composition of petcoke depends on the

composition of the petroleum feedstock used in refining.

Table 1. Petcoke Elemental Composition

% by weight

Carbon

80.0–95.0

Volatile matter

5.0–15.0

Hydrogen

3.0–4.5

Sulfur

0.2–6.0

Ash (including heavy metals)

0.1–1.0

Nitrogen

0.1–0.5

Source: American Fuel and Petrochemical Manufacturers, Petroleum

Coke Overview.

Health and Environmental Impacts

The recent increase in coking capacity in the United States

has raised concerns over the potential impacts of petcoke on

both human health and the environment. These impacts

may arise during various stages of petcoke’s life cycle,

including its production, handling, storage, transportation,

combustion, use, and disposal.

The U.S. Environmental Protection Agency (EPA) has

surveyed the potential human health and environmental

impacts of petcoke through its High Production Volume

Challenge Program. Additionally, in 2016, the U.S.

Department of Health and Human Services, Agency for

Toxic Substances and Disease Registry (ATSDR),

conducted an analysis on the potential impacts of

particulate matter (PM) and metals exposure stemming

from the Chicago petcoke storage facilities in 2013.

Most chemical analyses of petcoke, as referenced by EPA

and ATSDR, find it to be highly stable and non-reactive at

ambient environmental conditions. Most toxicity analyses

find it has a low health hazard potential in humans, with no

observed carcinogenic, reproductive, or developmental

effects. Only animal case studies of repeated-dose and

chronic inhalation have shown respiratory inflammation

attributed to the non-specific effects of petcoke as a dust

particle rather than the specific effects of petcoke’s

chemistry. The ASTDR analysis of petcoke’s particulate

effects found a potential for a “health threat to sensitive

individuals and to those with pre-existing respiratory

illnesses” on poor air quality days.

https://crsreports.congress.gov

Petroleum Coke: Industry, Health, and Environmental Issues

In regard to reactivity, petcoke is generally stable under

normal conditions. However, like many organic substances,

petcoke has the potential to become flammable or explosive

under certain conditions. Emissions from the combustion of

petcoke can release common pollutants (e.g., PM, nitrogen

oxides [NOx], and sulfur dioxides [SO2]), hazardous

substances, and CO2. When combusted as a fuel, petcoke

commonly has higher emissions of SO2 and CO2—per unit

of energy produced—relative to other comparable

hydrocarbons (see Table 2).

Table 2.Petcoke vs. Coal: Combustion Emissions

Fuel

HHV

Btu/lb

(avg.)

SO2 lbs./

Million

Btu

CO2 lbs./

Million

Btu

Petcoke

14,200

0.3–8.5

207–245

Pittsburgh #8

13,300

3.2–3.5

202–204

Illinois #6

11,000

6.0–8.1

201–203

Wyoming PRB

8,400

0.9–1.2

211–213

Texas Lignite

7,100

1.5–4.8

205–224

Coal

Source: CRS, with data for higher heating values (HHV) in British

thermal units per pound (Btu/lb) and sulfur and carbon content

ranges from Table 1 and M.I.T., The Future of Coal, 2007, p. 111.

Regulatory Requirements

Various aspects of the production, handling, storage,

transportation, combustion, and use of petcoke have been

addressed at local, state, and federal levels to protect human

health and the environment. While some federal statutes

address certain environmental impacts of petcoke’s life

cycle, most regulatory action and oversight has been

undertaken at the state and local levels, generally through

facility-specific permitting requirements. With few

exceptions, petcoke is not regulated specifically. Rather, it

is petcoke’s potential contribution to more general hazards

(e.g., air and water quality impacts such as haze, fugitive

dust, and stormwater runoff) that is monitored and

controlled through various regulatory requirements.

Waste Classifications

Federal law generally exempts petcoke from classification

as either a solid or hazardous waste. The exemption stems

from the scope of the statutory term “solid waste” as

decided in American Mining Congress v. U.S. EPA. In that

decision, the court held that materials recycled and reused

in an ongoing manufacturing or industrial process were not

considered to be “discarded” and, hence, not considered to

be “solid wastes.” Furthermore, in 1998, EPA identified a

list of petroleum refining wastes that would be subject to

federal regulations applicable to the management of

hazardous waste established under the Resource

Conservation and Recovery Act. In this rulemaking, EPA

stated that petcoke is not a waste but rather a “co-product”

of the refining process. In a separate rulemaking, EPA

further supported this classification by including petcoke

among its definition of “traditional fuels” (at 40 C.F.R.

§241.2).

Similarly, petcoke is not subject to the federal cleanup

authorities of the Comprehensive Environmental Response,

Compensation, and Liability Act (often referred to as

Superfund) because of the exclusion of petroleum from the

statute. The act defines a hazardous substance, pollutant, or

contaminant to exclude “petroleum, including crude oil or

any fraction thereof which is not otherwise specifically

listed or designated as a hazardous substance.”

Industrial Stormwater Runoff

The storage of petcoke may be regulated under certain

provisions of the National Pollutant Discharge Elimination

System (NPDES) permit program, as authorized in Section

402 of the Clean Water Act, if it is determined that runoff

from storage sites due to rain or snowmelt has the potential

to transport the substance to nearby surface waters.

Common NPDES permit requirements include the

development of a written stormwater pollution prevention

plan and the implementation of control measures. Control

measures could include site-specific best management

practices, maintenance plans, inspections, employee

training, and reporting. NPDES permit programs are

typically administered by state and local agencies.

Fugitive Dust

The handling, storage, and transportation of petcoke may

create local nuisance problems due to the release of fugitive

dust into the atmosphere. Regulatory oversight for this issue

is commonly implemented at the state and local levels and

generally takes the form of a fugitive dust control program.

These programs are often a necessary component to any air

permitting requirements for industrial sources, including

permits to install, operate, or decommission a facility.

At the federal level, EPA has set National Ambient Air

Quality Standards (NAAQS) for PM, among other

pollutants, under the Clean Air Act. If fugitive dust

generation is determined to be an issue at a facility that

produces, handles, stores, or transports petcoke, and if the

facility is situated in an area that EPA identifies as

“nonattainment” for PM NAAQS, then it may be possible

for state authorities to require the facility to report on and

manage its fugitive dust emissions—if it is not doing so

already—within the context of their NAAQS State

Implementation Plan.

Petcoke Combustion in Power Generation

When petcoke is combusted at power generating or other

industrial facilities, the resulting emissions would be

regulated under the specific standards set on the respective

facility. For example, federal regulations that may be

implemented could include EPA’s New Source

Performance Standards for Electricity Generating Units,

Mercury and Air Toxics Standards, Cross State Air

Pollution Rule for NOx and SO2, Title V Permitting

Requirements, Greenhouse Gas Reporting Requirements,

and Steam Electric Effluent Guidelines.

Richard K. Lattanzio, Specialist in Environmental Policy

https://crsreports.congress.gov

IF10507

Petroleum Coke: Industry, Health, and Environmental Issues

Disclaimer

This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan shared staff to

congressional committees and Members of Congress. It operates solely at the behest of and under the direction of Congress.

Information in a CRS Report should not be relied upon for purposes other than public understanding of information that has

been provided by CRS to Members of Congress in connection with CRS’s institutional role. CRS Reports, as a work of the

United States Government, are not subject to copyright protection in the United States. Any CRS Report may be

reproduced and distributed in its entirety without permission from CRS. However, as a CRS Report may include

copyrighted images or material from a third party, you may need to obtain the permission of the copyright holder if you

wish to copy or otherwise use copyrighted material.

https://crsreports.congress.gov | IF10507 · VERSION 2 · NEW