Gas carbon footprint

Recent threads have debated the safety of different fuel gases and
the “cleanliness” of acetylene but here’s a different twist to the
discussion of fuel gas - does anyone care about the carbon emissions
of these gases?

Per 1 million BTUs propane adds 139 pounds of carbon into the
atmosphere; for acetylene it is 159 pounds and for natural gas it is
117 pounds. This website will show you the source of the propane and
natural gas data U.S. Energy Information Administration - EIA - Independent Statistics and Analysis
and I’ve calculated the acetylene number (write to me privately if
you want the math).

How much gas is 1 million BTUs? You would have to use 46 pounds of
propane, 680 cubic feet of acetylene or 1,000 cubic feet of natural

I am asking the question because my company, G-TEC Natural Gas
Systems, sells torch boosters into many industries and we are
starting to get questions about greenhouse gases, especially in
southern California. Some municipalities are changing their
purchasing behavior to favor gases with lower carbon emissions.

Jewelers’ torches may use very little gas and add little carbon to
the atmosphere at a time, but over time CO2 adds up. So I am curious
to ask if, knowing these numbers, it is something you would find
important or consider when choosing a fuel gas.

Ed Howard
G-TEC Natural Gas Systems


How much gas is 1 million BTUs? You would have to use 46 pounds of
propane, 680 cubic feet of acetylene or 1,000 cubic feet of natural

There is more to it than just the numbers you are throwing around.
Depending on the work you are doing, I could get much more work done
with 680 c.f. of acetylene, than with 1000 c.f. of NG. And as for 46
lbs. of propane OMG could I get a lot of work done. Depending on
what I am doing at the time, the lowest carbon per BTU gas, could
give the most carbon per job number.

How do you really compare and contrast these numbers? I would
imagine direct studies in the specific work place would be best or
the only way. Then of course there is the question of using the NG
low or high pressure (you of course sell the high pressure) and how
would that effect the carbon per BTU number.

There is also the question of hydrogen such as the Spirig, which is
the same cost as your NG compressor along with a O2 separator. The
best way to use compressed NG would probably be with O2 from a
separator. The cost though would be lower if used with compressed
air. Would the results be lower?

Do you add in the carbon from the electrical use to run the units? If
you use bottle gas what about the carbon for bottling and delivery?
Perhaps we should all turn to TIG; but there’s that pesky ozone, and
still carbon from the electricity.

Lasers. Same as TIG.

I’ve been welding, brazing, and soldering for over thirty years and
have been seriously looking at your compressor and the Spirig for
the past three years and still can’t get to a final decision. I think
talking about a carbon foot print is only making matters worse since
the question depends much more on the work a person is trying to do,
than the carbon per BTU number alone. I’m thinking about just
soldering over a camp fire, at least it’s organic.

Half dead Dan

How much gas is 1 million BTUs? You would have to use 46 pounds of
propane, 680 cubic feet of acetylene or 1,000 cubic feet of
natural gas. 

BTU stands for British Thermal Unit. It is a measure of heat and
have nothing to do with volume. The same volume of fuel can produce
various amounts of heat, aka BTU(s), depending on condition of

Leonid Surpin

Jewelers' torches may use very little gas and add little carbon to
the atmosphere at a time, but over time CO2 adds up. So I am
curious to ask if, knowing these numbers, it is something you would
find important or consider when choosing a fuel gas. 

An interesting question, to be sure. But it may be a bit more
complex than the apparent math. For one thing, you cannot be sure
that the same number of BTUs would be used for the same task done
with different torches or fuels. If a job is easier and quicker and
goes with less fuss with one fuel, then perhaps it’s BTU use might be
less, while another job might be more difficult with a different
fuel, and the frustrated goldsmith might burn more gas for that task
than the equivalent of the other fuel. So the carbon footprint of a
give job might not be a simple comparison of BTUs per pound or unit
of fuel.

On the other hand, an almost stronger argument than just the lower
carbon footprint of natural gas is simply that for many uses in
jewelry, it’s actually often the best fuel to use anyway. When
available (It takes more than just the right pressure. My house, for
example, doesn’t have a gas line at all to it, so using natural gas
for me would mean buying it in compressed tanks like any other fuel.
Possible, of course, but more costly than natural gas from the city

I’m curious too, whether your carbon footprint figures are totals for
the gases, or just for the amounts of carbon released when the gas is
burned. To really reflect the environmental impact, you’d have to
figure in the carbon footprint not just of the gas when burned, but
also the carbon footprint of it’s production, including the energy
used to drill for it or manufacture it, as well as transport energy
costs, etc etc. All that gets somewhat harder to really figure out.
But my gut feeling is that again, natural gas is likely to come in
well on that account, especially if supplied as city gas. Lower
transport fuel consumption, for one thing… But I’m just guessing
there. Do you happen to have actual figures?

Peter Rowe

To a degree (maybe a pretty big degree) the carbon produced at the
bench with what ever torch fuel you use is rather small in comparison
to the carbon produced to get the gold/silver/stones out of their
natural environment, and for the metals, to mine, process and smelt
the materials, then process the bulk material into the forms you are
using. And one must take into account the carbon print from
processing all of the materials/equipment/processes that are needed
and used in the entire process. Environmentally, carbon foot print
wise, it is better to drive a Hummer at 7 MPG than a hybrid. The
batteries in the hybrid absolutely kills the carbon “savings” if the
total energy used to produce the unit (raw material to the finished
unit) and the mpg and the expected life of said unit are taken into
consideration. Weird but true.

I guess one must pick their battle carefully, then move forward.

John Dach

Keeping myself out of the car discussion, simply put…jewelry has a
very large carbon footprint in the grand scheme of things. Everyone
has to make their own decisions about carbon footprints, weighing the
pros and cons of each to find the right balance that they are
comfortable with. Consider the process of obtaining gems or metals
from mines…one can use lab-grown stones and recycled metals
instead, but might want to know how much energy is saved in actuality
by understanding the reclaiming process. This thinking is important,
but means more if we’re doing what we can where we can. It’s as easy
to use this kind of thinking about recycling in general…in fact, I
remember when it was used to say recycling didn’t make a difference.
In some ways that was true, and because public demand was there, more
adaptations were made.

I see this happening already in the jewelry arena to some extent.
I’m hopeful…there was a time when no one considered any part of
their life in terms of use/waste and the environment.


Kim Paluch

In reply to Daniel Culver’s well considered posting in regard to Gas
Carbon Footprints, properly generated multicell hydrogen/oxygen
generation (like a Spirflame[tm]) has the very best overall gas
carbon footprint when directly compared to piped or bottled gases.
However, this is really an unfair statement. As Daniel suggests, many
factors are not considered when determining the complete footprint
for every technology. Multicell technology uses far less energy to
produce a much larger volume of gas than a common water welder.
However, where does this energy come from? In France there is good
chance the electrical energy (approx. 45 percent) is supplied from
Nuclear Energy, while in America the same volume of energy could
easily be supplied by coal. This would give the Spirflame[tm] in
France a smaller footprint than the Spirflame[tm] in America. And,
since all Spirflames[tm] are made in Switzerland, this might be added
to by the greater shipping distance from Switzerland to America when
compared with Switzerland to France.

Usage itself is an important factor. There is also the concept in
regard to the operational life of the gas generating system and how
much of it is recyclable. Spirflames[tm] even in harsh industrial
applications last a very long time, and are usually upgraded after
many years of use, not replaced as other units must be. We have
specific programs in place for this purpose.

Other considerations in regard to what percentage of a suppliers
firm is involved in renewable energy such as fuel cells and solar
where Spirig (our firm) is deeply involved, and holds a number of
critical patents, as well as being used to manufacture those

As a firm with a carefully considered gas, carbon and environmental
footprint (we consider it one indicator of profit). A firm with
distinct advantages, we still need to state, discussions of a
products “carbon footprint” especially as a selling point can be
inaccurate, perhaps deceptive once all factors are carefully

We prefer to focus on operational benefits which are clearly defined
in direct comparison with other products. How our product improves
your product and makes it easier to produce. It is clear, for many
heat sources, inaccurate or incomplete measures are being stated.
So, for now, we do not use our favorable footprint as an advertised
benefit and will probably not do so until it becomes a more easily
defined and a better measured concept for all. Thank you Daniel
Culver and Peter Rowe for posting not only knowledge, but wisdom
into this interesting subject.

Best Regards,
Gary W. Miller
Sr. Technical Advisor