I have recently become intrigued with kerosene and its use
in home heating. Part of this interest stems from the fact that one of my
nephews dabbled for a while in the art of fire breathing which uses kerosene as
well as my interest in the history of the oil industry which I share with students
in the Energy
and Sustainability MBA program at
Franklin Pierce University via Daniel Yergin’s book, “The Prize,” which is
a well-written account of the oil industry.
Jeddon Mooiman showing off his fire breathing skills.
Kerosene (known in the UK and many of the old British colonies
as “paraffin”) was the first crude oil distillate that made its way into common
use. It came into commercial production in the 1850s and quickly displaced the whale
oil that was used for lighting at that time. Kerosene has a long history of cooking
and heating applications and is still extensively used in Africa and Asia as a
cooking and lighting fuel. Today, the largest use of kerosene is as aviation fuel.
When I was growing up in Africa, a lot of cooking in rural
areas was done on kerosene-fired Primus stoves, such as the one shown in the
figure below. The basic design for this kerosene stove comes from 1892 and the and
has not changed much since then. Many of these units, or similar ones, are
still in service in Africa and Asia. In fact, these were the stoves of choice
for many of the polar expeditions and when Hillary and Tenzing ascended
Everest for the first time in 1953.
When crude oil is distilled, the kerosene fraction boils off before the diesel/ home heating oil (HHO) fraction. As a result, kerosene is a little
less viscous and slightly more volatile than diesel and the hydrocarbons in kerosene typically contain 9 to 16
carbons, whereas diesel contains hydrocarbons with 10 to 20 carbon atoms. (The exact blend of
hydrocarbons depends on the source of the crude oil used in the refining
process as well as the type of refining process used.) One of the best features
of kerosene is that it stands up to colder temperatures much better than
diesel. At very low winter temperatures diesel and HHO fuels can start to become
slushy as the longer chain hydrocarbons begin to gel, forming waxes, which can
plug up fuel lines and filters, causing heating furnaces to shut down. These
waxes start to appear at temperatures known as the cloud point of the fuel. As
temperatures continue to drop below the cloud point, more wax is formed and the
fuel can become so slushy that it will not even flow. This is known as its gel
point. Home heating oil has a cloud point of 9 to 10oF but kerosene
will only begin to cloud at -40oF. With its lower cloud and gel point,
kerosene is often blended into transportation
diesel in the winter months to ensure that the diesel does not gel in the tanks of trucks and other heavy equipment. Aircraft
flying at high elevations are subject to very low temperatures and the aviation
fuel variant of kerosene, jet fuel, is therefore ideally suited to this low
temperature environment and application.
It is the cold temperature stability of kerosene that accounts
for its frequent use as a home heating fuel for mobile or manufactured homes. In
mobile homes using oil heat, the fuel storage tanks have to be located outside
of the residence where the fuel is subjected to the cold winter temperatures. Here
in, New England, where temperatures regularly reach single digit temperatures,
having typical #2 HHO in an outside storage tank could be problematic for
heating units.
Many of us with typical stand-alone homes give little
thought to mobile homes and their particular heating challenges. It turns out that mobile housing units are a
large part of the NH housing stock and it is estimated that there are ~30,000
units in NH (5.7%
of the 519,000 residences). This means that there are many NH residents who
are obliged to use kerosene due to the need to locate the storage tank outside
of the home. The problem is that kerosene is the most expensive of the commonly
used home heating fuels. As shown by the NH data in the figure below, kerosene
is consistently more expensive than regular #2 HHO - typically costing about
$0.50/gallon more. (As an aside, on an energy content basis, the most expensive
way to heat is with electricity, then propane, and then kerosene, followed by
regular HHO. See my Under
Pressure and Closer
to Home posts.)
These higher fuel prices clearly impact those least able to
afford it. Moreover, it has been
reported that mobile homes built before 1980, which comprise a large part
of NH mobile home stock, have, due to poor insulation, an energy consumption
per square foot that is 53% higher than other types of homes. With the
combination of higher energy consumption and higher fuel prices, it is clear
that folks living in mobile homes are deeply impacted by cold weather and home heating expenses:
lower income families who live in mobile homes therefore spend a larger portion
of their income on heating expenses compared to families living in better
insulated residences. For this reason, weatherization programs
directed at improving the insulation of these mobile homes, such as was carried out
recently in New Hampshire, should be encouraged.
Many of us are familiar with self-standing kerosene heaters
such as those shown below. There is the torpedo type one often finds on
construction sites or in warehouses or the stand-alone type one might find used
for supplemental or backup heat in backwoods cabins, workshops or barns. The
appeal of these types of kerosene heaters is that many designs do not require
electricity to operate – some rely on wicks to draw kerosene to the combustion
area and some, like the primus stove pictured above, require a manually
pressurized fuel tank. Some modern stand-alone kerosene heaters have electrical
fans to blow the warm air into the room but the main feature of these stand-alone
heaters is that they aren’t vented. As such, the combustion products, largely
water vapor and carbon dioxide, are released into the heating space. The danger
is that improperly adjusted kerosene heaters can release the highly poisonous
carbon monoxide, which could have deadly consequences. Any home or enclosure
using a kerosene heater should, as a matter of course, be fitted with a carbon
monoxide detector. Moreover, a window should be always opened a crack to allow
some circulation and to prevent the buildup of carbon dioxide and other
combustion products.
The kerosene-based home heating systems installed in mobile
homes are not the unvented types shown above; modern units are fan-driven
ducted systems which discharge combustion off gases directly outside. These are
similar in design and configuration to home heating systems that use regular HHO.
Two grades of kerosene are available for sale. There is K-1 kerosene
which low in sulfur (<0.05%) and higher sulfur K-2 kerosene (<0.5%). For unvented heaters, the K-1 grade is the
recommended type. The K-2 grade is the type that is often used in mobile homes
with vented heating systems. Like
untaxed HHO, kerosene used for home heating purpose is dyed red to
distinguish it from its taxed transportation equivalent
Data on kerosene sales for home heating applications is
tracked by the Energy Information Agency (EIA) and historical data for NH is presented
in the chart below. We noted in
an earlier post that current HHO sales were off about 55% from their 2004
highs. We also see a decline for residential kerosene sales - but here the drop
off is of the order of 90%! NH kerosene
sales continue to decrease – consumption
has decreased from 7 million to 2 million gallons per year just since
2010. (As a comparison, bear in mind that the HHO consumption in NH is of the
order of 100
million gallons per year.) I am
pretty confident that these numbers do not reflect a decrease in the number of
mobile homes. Instead they indicate that folks living in mobile homes are
making choices regarding their use of expensive kerosene.
Source: EIA, NH Residential Kerosene Sales
This is not just a NH phenomenon. Residential kerosene sales
are down across the entire US.
This decrease intrigued me and so I
chatted to a number of folks involved in the NH kerosene business and asked
them about the decrease in kerosene sales data. As is typical in a case like
this, there does not appear to one single reason for the decrease in usage. Instead
a number of factors are at play but they are largely price-driven. Here is what
I have learned:
- Kerosene is more expensive than regular HHO so mobile home residents have sought alternatives. For a typical 180-gallon delivery, a resident can save $90 by getting HHO instead of kerosene. The low temperature clouding and gelling problems with outside storage tanks in winter can be combated by the addition of anti-gel additives that reduce the cloud point. These additives can cost $10 to $30 per tank and so there are savings for the resident. However, some oil suppliers have expressed concerns about poor mixing of the additive in a typical oil tank and question the effectiveness of these additives.
- Some oil dealers will supply a blend of expensive kerosene and lower cost HHO to lower the cost of a heating fuel delivery. In these circumstances, it likely that the kerosene content gets lumped in with the oil numbers when data is reported - which then artificially decreases the kerosene consumption numbers.
- Some kerosene users will switch back and forth between kerosene and HHO during the year to reduce their heating bills and will use kerosene only in the very cold winter months.
- Many mobile home owners have converted old kerosene-based heating systems to electrical space heaters or propane systems. Sometimes these changes are done based on the belief that propane systems are better and some are driven to do so because they live in a community that does not allow the installation or replacement of an outside kerosene storage tanks.
- The number of oil dealers supplying kerosene has declined. Fuel storage facilities, along with the associated tanks, pumps and piping are expensive, and many dealers have found maintaining kerosene inventories, along with the related storage and transportation logistics, unattractive in the face of declining sales.
In
my last post, I noted that HHO is a dual
purpose fuel. It is used as for
home heating and, in its low sulfur diesel form, it is used for transportation:
it is often the larger transportation market dynamics that ends up dictating
the price for HHO. Kerosene is similarly a dual purpose fuel used for home
heating and transportation. As noted earlier, in winter kerosene is added to
diesel in order to extend the temperature range of the fuel. Far more
significant, however, is its use as an aviation fuel. To give you a sense of
the US
market, in 2012 21 billion gallons of jet fuel were consumed, compared to
81 million gallons of kerosene consumed for home heating, commercial,
industrial and farm use. The jet fuel market is 260 times larger.
In making inquiries about why kerosene is more expensive
than regular HHO, it turns out to be more of a supply issue. Only about 10% of oil refinery production, see the table below, ends up as kerosene. This
limits its availability and, on top of that, the strong demand for jet fuel
continues to increase.
Kerosene, in its jet fuel formulation, has another important
use: it is used to generate electricity. A few weeks ago, PSNH
reported that they were requested to fire up their 20 MW jet fuel
generators located at the Merrimack station in Bow, Groveton and Tamsworth.
This is generally a rare event and was driven by the lack of natural gas
availability for power generation. The
challenge with these oil-fired generators is that the jet fuel is expensive
compared to natural gas and coal so that they are really only backup units used
to meet high peak demand operations. Some operations have converted their oil-fired
backup units to run on cheaper natural gas. High oil prices also led to some
operators reducing the amount of oil in their storage tanks, which left the
region short of oil-fired backup generating capacity during the 2012/2013 winter
when it was needed.
This winter, ISO-NE, the regional body responsible for
coordinating the entire New England electricity market, instituted a Winter Reliability Program in which ISO-NE procured additional generating capacity
from oil-fired operations such as PSNH. ISO-NE paid participants in the program
~$0.60/gal to keep fuel oil in storage to be available when requested. This
program has been effective this winter and oil-fired backup capability has been available when
needed. The chart below shows the generation of electricity in New England from
different sources during the month of January 2014. Natural gas and nuclear
generate most of the electricity in the region but the early January cold snaps
had oil-fired generators kicking in (shown by the light blue line) and during
the very cold weather towards the end of January, oil-fired generators were
producing a lot of the region’s electricity. In fact, on Jan 24, 2014, oil was
supplying 14% of the region’s electricity, as measured on a daily basis.
We have covered a lot of ground on this post, ranging from Primus
stoves to PSNH’s use of kerosene to generate electricity, but here are the main
takeaways regarding kerosene usage in NH:
- Kerosene is a versatile fuel which is very useful in low temperature applications, such as blending with diesel in winter and for mobile homes with outside fuel tanks. However, its main use is as an aviation fuel.
- Kerosene is ~$0.50/gal more expensive than HHO as a home heating fuel in NH.
- Use of kerosene as a home heating fuel has plummeted over the past decade, driven largely by price.
- Kerosene is a useful back-up fuel that can be used to generate electricity when natural gas supplies are constrained or prices get too high.
- Finally, if you are planning a traverse of the South Pole or an ascent of Everest, you may want to start scouring yard sales for old Primus stoves.
Until next time, remember to turn off the lights when you
leave the room.
Mike Mooiman
Franklin Pierce University
mooimanm@franklinpierce.edu
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(*Kerosene Hat – The title of Cracker’s breakthrough 1993
album. I always enjoyed this group as I found many of their songs clever,
catchy and some quite dark. Even though this tune is from their previous album,
this is my favorite Cracker tune, Teen Angst. As an old
folkie I love the “what the world needs now is another folk singer like I
need a hole in my head” sentiment.)