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"HOT" gas

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  • "HOT" gas

    Hey guys, quick question. I've got a number of gas wells, (175+) and access to a butt load of free (or really, really inexpensive) ng, however the gas is about 20% too "hot" at 1224.6 btu/scf. Now, I'd like get by using it with minimal treatment, as propane and ethane rejection plants are pricey to say the least ($80,000.00+). So, I was wondering, how "HOT" can your gas be and still be safe to use in a motor? And, in lieu of de-propanizing the gas, could I just introduce some quantity of non-combustible to the gas, like n2, to reduce the btu's to bring it closer to 1025?

    Oh, keep in mind, these are converted Diesel engines, not gasoline retrofits or dedicated. So, I presume, the Diesel mode of combustion makes these things more sensitive to higher btu gas, right? So, what do I do?
    Last edited by Ben Cubbedge; 06-18-2008, 12:03 PM.

  • #2
    Re: "HOT" gas

    Are you currently selling gas to the utilities? It is likely that there would be funding to build the seperator, and cost coverage could be in the range of 90%. You could have a lucrative business opportuniy staring you in the face. There is a growing market for these various gas'.

    Where are you located?


    • #3
      Re: "HOT" gas

      Ben, Curtis, et al,

      Let me start by saying, "I'm not a chemist, but..."

      we encountered > 1200 btu gas in Southern Ohio and felt blessed! The more btu's the better is my understanding. I would see no problem using the higher btu gas in NGV's.

      Control of the combustion process in diesel blends is a concern, but again, if you're monitoring exhaust temperatures and reducing NG accordingly, I don't see the problem.

      Any one else???



      • #4
        Re: "HOT" gas


        How do you mean "lucrative" business opportunity? As is, I'm not sure to whom we're selling our gas, but I could find out. In so far as "pipeline" quality, it comes out of the ground that way, and requires zero treatment. However, I'm afraid it may require treatment to burn in an I.C.E. I'm located in Eastern Kentucky, and would love to have someone buy a de-propanizer for me. That would rule, so any info or advice you have, please let me know.


        Our gas likely comes from the same reservoir. However, we're retailing our gas to fleets with dual fuel motors. So, in order to maximize their savings, they need to burn as much cng as possible, and as little diesel as possible. So, by regulating the btus of the fuel by reducing cng is a problem, as we sell less ng and they buy more diesel. So, I need to know how "hot" my gas can be?

        The conversions have exhaust-temp and combustion chamber sensors that would shut the thing down if it got too hot, however I would like to avoid that possibility entirely. So, I guess my question to you is, what kind of trucks do you operate, what kind of motors, and how do the motors run on 1200+ btu gas?

        Thanks for the help.


        • #5
          Re: "HOT" gas

          What on earth are you doing with all that gas?
          Do you have an analysis/breakdown of what's in your gas?
          How far are you from I-64 and/or I-77?
          Are you aware you're in the middle of a great void in the CNG infrastructure?
          Last edited by cnghal; 06-18-2008, 12:04 PM.
          Your Friendly Nazi Squirrel Administrator


          • #6
            Re: "HOT" gas

            Thanks, Hal. I was just going to suggest he contact the gas purchaser he's currently selling to, or contact a private lab and get a composition breakdown of his gas. It's a starting point.

            Obviously you are selling the gas to someone... the same someone that deposits all that money into your bank I would suspect. Do you have mineral rights on your land? If you were pumping up oil, who would it belong to? Is the gas yours or are you on a land lease? If you own the land, and everything below it, you should be financially set. You don't seem to know who's getting the gas, which I find troubling. It indicates that you have no financial interest in the gas, perhaps even the land. Many gas co's lock up the rights to the gas and generously allow you free gas for your needs... but, unless they're leasing the land from you, you won't see a dime and have no right to sell anything.

            You need to determine these things before you get very far into this.


            • #7
              Re: "HOT" gas

              The gas play is several miles from 64/75.

              I work with a Natural gas development company.

              I deal with the technical, not the financial. I'm vested in the gas, though it belongs to a few of us.

              The gas is 100% ours, leased in perpetuity. Some of its stranded, i.e. there is no pipeline capacity, so we can't deliver it. So we can't sell it.

              In terms of opening a large scale cng station, or a number of stations along the interstate; that's entirely possible as pipelines criss-cross this part of the country like a wicker chair. So, that's a possibility.

              To deal with the issues of actually selling the gas, we've moved ahead in a number of joint ventures with fleets and engine retrofit developers. We're nearing the end of the contract phase, and about to begin the first phase of development. Which brings us to where we are now.

              Here is a profile of the gas. . . it comes out of the ground like this, mind you.

              Methane %76.59
              Ethane 11.243
              Propane 4.815
              i-Butane .451
              n-Butane 1.355
              i-Pentane .291
              n-Penatne .360
              c6+ .42
              Moisture 0.000
              N2 4.172
              CO2 .296
              H2S 0.00
              neo-C5 0.00

              TOTAL BTUs= 1207.1 btu/cf

              Its really clean, great quality nat. gas, but its about 21% too "hot", given the standard 1020 btus/scf of Methane. No water, no H2S, small % non-combustibles. If anyone has any ideas, I'm open to suggestions.

              So, to answer everyone's questions succinctly:

              We would prefer to wholesale the gas, but there's about a third that we can't sell. So we're trying to create a market.
              Last edited by Ben Cubbedge; 06-18-2008, 01:33 PM.


              • #8
                Re: "HOT" gas

                Thanks Ben,
                Sounds great, got the brain gears a turnin. I'm working on several similar situations with customers in Texas.
                I've got a couple more questions for you if you don't mind.
                What's the average head pressure of your wells?
                What's the average or allowable gas flow from each well?
                How many are stranded and how far apart are they?
                Are the stranded wells accessable by semi-tankers?

                Thanks again,
                Your Friendly Nazi Squirrel Administrator


                • #9
                  Re: "HOT" gas

                  The well head pressure is, approx 50psi +or-. The max allowable flow is as much as possible. Chesapeake and Columbia will allow us to transport our gas on their gathering system, so even though they won't let us sell it, they'll allow us to transport it. We'll just have to pay the transportation fees and shrink. So, we don't need any trucks to move it to the retail point, that's taken care of.

                  Basically, all I need to know is how "hot" is too "hot", if anyone has any experience. Also, Curtis, you said something about getting my de-propanizer, ethane rejection unit more or less paid for. How?


                  • #10
                    Re: "HOT" gas

                    DOE and state grants and infrastructure tax credits for a start.
                    I'm thinking "too hot" isn't as much a problem as too little methane.
                    I'm not sure if it's a federal standard or not, but most CNG for sale is at least 90% methane. From what I've been told, that's the reason there are no stations in some areas like Ventura County in California. CARB won't allow thier "pipeline gas" to be used as a motor fuel.

                    The transport question was more in the realm of ROI of NG powered stranded well processing and compression equipment to totally bypass the gas companies and utilize the stranded wells for a mother/daughter type of station network. Just something I'm working on for some stranded and capped wells in Texas.
                    Last edited by cnghal; 06-18-2008, 07:00 PM.
                    Your Friendly Nazi Squirrel Administrator


                    • #11
                      Re: "HOT" gas

                      Ben, there are lots of sources for grant funding for infrastructure, particularly if it involves the public in any way shape or form. I sounds like you have the makings of a co-op there. You may have to decide how best to take advantage of your situation and then research available grants to offset your expenses. There may also be federal tax advantages for some applications. Public infrastructure is a hot button these days and Clean Cities may be a starting point, if you have them in your neck of the woods.


                      • #12
                        Re: "HOT" gas

                        Methane % at Utah stations runs in the low 80% range. Not far from your 78%. I'd say it's fine. If the engine "pings" due to low octane, that would be an issue. But that wouldn't be a problem in most CNG vehicles since they don't have a high enough compression ratio to really take full advantage of natural gas. The acid test would be a newer Civic GX: If that doesn't "ping" you're okay.

                        Another issue would be exhaust temperatures, but those are already so low in CNG vehicles that the real challenge to the designers is not ENOUGH heat.


                        • #13
                          Re: "HOT" gas

                          Diesel 130,000 btu/gallon
                          My gas 156,650 btu/dge

                          So, insufficient octane, energy, or heat won't be a problem. Knocking the rods through the bottom of the crank case might.