Novel CNG dispensing technology awarded U.S. patent
A friend recently sent me pictures of trucks waiting in long lines to get refueled at an Orlando, Florida, compressed natural gas 鈥淐NG鈥� station. He sees these lines every morning when he drives to work. My friend innocently thought that seeing a huge demand for CNG, day in and day out, is good for the CNG industry. But any dispatcher or truck driver will tell you that waiting in gas lines robs them of time, and in turn, the ability to make money.
Unfortunately, what my friend witnesses each day is a primary reason why many companies hesitate about converting their fleets to CNG from diesel. True, CNG is a cleaner fuel than diesel. And it generally costs less than diesel and the maintenance costs for CNG engines is 50 percent less than diesel engines. CNG engines last much longer than diesel engines and you get more miles per gallon using CNG than diesel. But time is money and while the lines may be due in part to the lack of CNG stations, it蘑菇视频 also due in large measure to the inefficient manner of current CNG refueling technology.
CNG is dispensed by a 鈥渃ascade鈥� fueling system. CNG fuel islands are located near local gas pipelines. The pipelined gas is compressed and stored in a series of three spherical steel tanks. The system equalizes the pressure from each spherical tank to the awaiting vehicle tank, and the equalization of pressure provides a complete fill-up for the vehicle tank.
The spherical storage tanks typically hold about 75 gasoline gallon equivalent 鈥淕GE鈥� (about 25 GGE per tank) but only about 40 percent of the gas is used efficiently. This may work fine for the first one or two vehicles that need fuel. But the other vehicles in line are then dependent on the speed of the compressor to pull the gas from the local pipeline. Compressors are very expensive to buy. Typically, CNG compressors cost in the neighborhood of $500,000. And they require a lot of electricity to operate. Compressor maintenance costs are high too.
Storage tanks are also very expensive. The spherical tank cascade system usually costs about $100,000 for three tanks.
Many local distribution pipelines are not able to handle increasing CNG demand. For example, a neighboring high gas user, such as a hospital or manufacturing plant, will draw from the same pipeline that a CNG gas station uses to meet its customers鈥� needs. There are very few locations in the country that can satisfactorily meet the gas pressure and volume from these pipelines to meet sufficient fast-fill, i.e., CNG-on-demand, fuel islands.
Inconsistent demands for natural gas throughout the day by neighboring customers sharing the pipeline create widely disparate volume and pressures that are detrimental for optimum operation of open-traffic fast-fill CNG fuel islands. Decreased pipeline pressure increases the time required to fuel vehicles and as more vehicles convert to CNG, the fuel demand may exceed the supply available to any given fuel island because the island is dependent on the supply offered by the neighborhood pipeline at any given time.
In full disclosure, I am president of a company that specializes in CNG fuel system development. On June 7, my company was issued a patent that addresses these concerns. It took us over four years to develop the system and over 3 陆 years to navigate it through the U.S. Patent and Trademark Office in Washington, D.C. My company has about a dozen additional patents in various stages of development that provide solutions for other natural gas fueling issues.
The recently issued patent (U.S. 9,360,161) provides a system of CNG storage tanks and gas compressors which are designed to collect, store and compress natural gas on site in a manner that accounts for fluctuations in gas supply from pipelines or other sources and accounts for fluctuations in vehicle refueling demands. In short, it emulates the tried and true dispensing system of the petroleum industry. So instead of having long lines at a CNG dispenser, the patented system can fill multiple vehicles at the same time, with the same speed and efficiency as liquid petroleum fuels without worrying about the pipeline pressures, or availability of gas in the conventional cascade system. The system costs about 2/3 less than typical cascade systems, and is exponentially more efficient.
The system is comprised of a series of tanks made of composite resin capable of handling pressures of 5000 pounds per square inch 鈥減si.鈥� (Cascade systems typically operate at 3200 psi.) Instead of a cascade system, the tanks are divided into two banks: a bulk storage bank and a dispensing storage bank. The bulk storage bank feeds the gas into the dispensing storage bank as the gas is dispensed into customers鈥� vehicles. The goal is to keep the gas pressure in the dispensing storage bank at its maximum at all times, while the bulk storage bank continually experiences descending pressure as it continuously fills the dispensing storage bank.
During off-peak electricity hours, the bulk storage bank is refilled by the local pipeline so that compressor utility costs are at a minimum. Transferring the gas from the bulk storage bank to the dispensing storage bank is accomplished throughout the day via a low horse-powered compressor, which is much less expensive to purchase and operate than traditional compressors. The system was invented by my partner, Keith Barker.
This patented CNG dispensing technology makes the dispensing of CNG as easy and convenient as refueling with diesel or gasoline, thus eliminating the perpetual long lines my friend in Orlando witnesses every morning. Since refueling wait times will no longer be a factor, we expect this system will encourage fleet operators to convert more vehicles to CNG.
On a personal note, although there are significant business risks associated with developing technology companies, it is fun to be part of a team that solves important problems, such as reducing the wait time of dispensing natural gas. It is especially satisfying when your efforts are recognized by the issuance of a patent.
David Pearl is vice president of Infinity Resource Group, Inc., a professional mineral rights consulting firm, specializing in the leasing and sale of mineral rights in Pennsylvania, West Virginia and Ohio. Pearl is also president of a natural gas fuel dispensing patent holding company and director of a natural gas fuel island development company. Your questions are welcomed by calling 412-535-9200 or by emailing IRGOilGas@gmail.com.