CNG Primer IMW IMW Industries Ltd. and Product Overview
CNG Primer a. What is CNG? CNG is compressed natural gas. CNG systems take natural gas (the same gas we heat and cook with) from underground distribution pipes at relatively low pressures and compress it to pressures of 3600 psig (or more) to fuel vehicles or fill transportation trailers that can carry the gas to off-pipeline users. The gas is typically used at lower pressures but compressing it allows it to be transported in much higher volumes, making the overall use more efficient. b. Why is it a better fuel? CNG as a transportation fuel is much lower in a number of harmful pollutants, particularly carbon dioxide, sulphur, lead, carbon monoxide, nitrogen oxide, and particulate matter. It is the cleanest burning fossil fuel and produces approximately 25% less greenhouse gas when used in internal combustion engines, compared to gasoline and diesel. As well, its overall lifecycle impact (well-to-wheels) is much better for the environment than other refined liquid fuel products. For these reasons, the implementation of CNG fuelling for transportation applications is a key component in the clean air strategies of many major cities worldwide. c. Is it safe? Natural gas is neither corrosive nor toxic, its ignition temperature is high, it is lighter than air, and it has a narrow flammability range, making it an inherently safe fuel compared to others. Natural gas cannot contaminate soil or water. It always rises to the atmosphere when outdoors, unlike other fuels which are heavier than air and can pool, either as a liquid or a vapor, on the ground. Natural gas is normally odorless but is generally odorized with mercaptan, which allows it to be detected at 0.5% concentration in air, well below levels that can cause drowsiness due to inhalation and well below the weakest concentration that can burn. In practice, CNG use worldwide has resulted in very few incidents of damage or injury; most of which were the result of improper equipment use. d. Is it available? Yes, natural gas is abundant worldwide and is typically is found in conjunction with oil deposits. These are known as conventional gas reserves, which are estimated at more than 60 years supply (177 Trillion cubic meters 1 ). As well, natural gas is available from unconventional reserves such as coal bed methane and shale bed methane in very large quantities that can extend the global reserves for hundreds of years (920 Trillion cubic meters 2 ). Recent improvements in drilling technology have made significant increases in the amount of available gas, ensuring a very long-term, price-stable commodity. 1 Source: BP Statistical Review of World Energy June 2008 2 NPC Global Oil & Gas Study: Topic Paper #29 July 2007
e. What does CNG cost?despite its other compelling advantages, often, the greatest impetus for the use of CNG globally is its low price relative to gas or diesel. While prices and availability vary from country to country, generally, CNG vehicle fuel at the pump represents a savings of 30 ~ 60% for the driver or fleet operator. In addition, there are other mechanical advantages for the vehicle engines, which may reduce overall maintenance costs. For the country developing CNG infrastructure, there may be other critical economic advantages such as a reduced reliance on foreign oil and/or a reduction of costly subsidies that may exist on liquid fuels, i.e. Indonesia. Worldwide, natural gas deposits are abundant and far better distributed than crude oil deposits, making them a viable resource for many countries. Non-vehicular use of CNG (i.e. gas-fired power generation), when compared to diesel or heavy fuel oil, promises to represent even better cost savings than those realized by vehicle operators. This is a relatively new and extremely promising market segment. f. So, why doesn t everybody use it? One of the principal disadvantages of CNG fuel is the relatively high cost of fuelling infrastructure development, i.e. CNG fuelling stations. Most people take it for granted that gasoline and diesel are widely available; however, because CNG is still at a relatively early stage of widespread market development, its availability cannot be guaranteed in all countries or regions. This can slow down the adoption of CNG vehicles in fleet use, as operators may not want to be confined to limited fuelling access. This is the chicken and egg conundrum that many potential industry participants struggle with which comes first, the CNG station or the vehicles? yet in many developing countries, proponents have developed a build it and they shall come attitude, which has proven to be generally true. In some markets, natural gas is not a domestic resource (i.e. Japan); yet the importation of liquefied natural gas by ocean tanker still provides an overall economic benefit by the time it reaches the CNG vehicle operator. g. Why does infrastructure cost so much? CNG systems are generally built to order to meet the specific site requirements of the customer, i.e. electrical supply, gas pressure, overall flow requirements. This factor, along with the high-pressure and safety aspects of CNG systems, makes them relatively costly to manufacture. Unlike liquid fuel systems, which require only a storage tank and a pump, CNG systems require multi-stage compression, high-pressure cooling, high-pressure storage, dispensing, and metering of a gaseous medium, which is considerably more difficult to manage. Despite the high capital cost for infrastructure development, CNG systems can have an incredibly positive return on investment in most markets. In many cases, payback (of equipment) can be amortized over periods of less than two years due to the high latent demand for CNG fuel by vehicle operators. Overall payback periods, of course, depend on the total station development costs (i.e. construction & land) and rate of usage.
Products h. Overview: IMW designs, engineers, manufactures, assembles, and tests complete CNG system components such as high-pressure compressors, gas dispensers, gas control panels, electrical control panels, storage systems, equipment enclosures, piping systems, heat exchangers, and specialized pressure products (filters, back-pressure regulators, pressure vessels). IMW is a full-service manufacturer with all machining, fabrication, assembly, and testing done in-house under various approvals with the BC Pressure Vessel and Boiler Branch, American Society of Mechanical Engineers, Canadian Welding Bureau, ISO9001, and others. IMW also provides engineering and technical services for installation support, equipment commissioning, troubleshooting/maintenance, and training. It should be noted that there are a wide range of CNG system designs that are determined by the nature of the station site, the intended use, the type of vehicles available, and the gas supply characteristics. IMW can assist with the system and station design to maximize the efficiency of the CNG operation. i. Key components in CNG systems i. Compressor: The compressor is the heart of a CNG system. It compresses gas in multiple stages to pressures of 3600 ~ 4500 psig, and cools gas between stages and at discharge. The compressor is designed to maximize overall flow rate and efficiency. Generally, the compressor, drive motor (or engine), heat exchanger, filtration, piping, and instrumentation are mounted together on a single structural skid for easy maintenance. Available in a variety of drive types (electric or NG engine), cylinder sizes, configurations, cooling methods, speeds and options. ii. Enclosure: Free-standing, weatherproof housing for compressor and associated systems. Provides sound attenuation and security. Designed for all climate types. Available with a variety of optional features for extreme climates and sound requirements. iii. Priority/ESD Panel: Controls gas flow from the compressor and storage systems to maximize the vehicle filling speed and optimize the efficiency and safety of the fuelling system. Typically mounted on the compressor skid. Available in a variety of configurations to work with different flow rates, storage systems, and dispenser arrangements. iv. Dispenser: CNG equivalent of a gasoline pump. It is the customer interface at a CNG fuelling station that dispenses and meters the highpressure gas to the vehicle and displays the volume and price of the dispensed product. This is the preferred filling device for fast-filling vehicles in times comparable to filling with liquid fuels (gas/diesel). Available in a variety of configurations for different types of vehicle filling and pressures.
v. Gas Dryer: If the supply gas is not sufficiently dry (less than 4 lbs/mmscf), or the operating conditions are particularly cold, there is a risk that water droplets can form inside the compressor under the high pressure conditions. The presence of water can encourage corrosion or cause hydraulic interference that can damage the compressor. Moisture can also cause ice to form in the vehicle fuel systems, interrupting gas flow. To prevent this, the gas supply can be pre-treated with a desiccant dryer to remove excess moisture prior to compression. vi. High-Flow Fill Post: This type of fill post is typically used for high-volume filling of transportable CNG trailers. Equipped with gas metering, filtration, and large diameter process tubing/hoses. vii. Time-Fill Post: This type of simple, unmetered fill post is used for time-filling vehicles. viii. Time-Fill System: Time-fill systems are used to fuel return-to-base fleet vehicles on an overnight basis. Each vehicle connects to a fill hose at each parking stall and all vehicles fuel together slowly. The fill hoses are connected to a common supply line coming from the compression system. Time-fill controls regulate the system fill pressure and provide over-pressurization protection. This type of system is fairly simple and cost-effective where fast-filling is not required. ix. Gas Storage: High-pressure gas storage can be configured with various types of vessels (DOT and ASME), pressures, volumes and operating methods. 1-, 2-, or 3- bank storage systems are used to maximize the speed of vehicle fast-filling as well as smooth out the operating cycle of the compressors. The storage setup is usually determined by the type of filling expected, i.e. peak filling or constant rate. x. Decanting Panel: This device is used as an interface between a transportable CNG storage trailer and the compressor inlet piping. It allows the compressor to be connected to the mobile gas supply with shutoff control. xi. CNG Trailer: Mobile CNG storage trailers are used to move high-pressure gas from a compressor station situated on a gas pipeline to areas that are not serviced by a pipeline. CNG trailers towed by transport tractors act as a virtual pipeline to move gas quickly and effectively to off-pipeline applications like vehicle fuelling stations, industrial applications and residential applications. Typically, one mother station on a pipeline can supply gas to 3 ~ 5 daughter stations off-pipeline, at distances up to 200 or 300 km away. The quantity, volume, and configuration of the trailers depend on the distances and the station flow volumes. xii. Pressure Reducing System (PRS): A PRS is typically used at a non-vehicular offpipeline gas destination in order to reduce the pressure of the trailer gas to a useable, low pressure. The PRS acts as a multi-stage pressure reducer and reheater to condition the gas properly for utilization in industrial and residential applications.
xiii. Mobile Refuelling Unit (MRU): The MRU is a transportable CNG compression and filling system, typically designed to be mounted on a 40 transport trailer. Natural gas engine drivers and hydraulic systems permit stand-alone operation, except for the necessary gas supply connection. MRUs are often used for emergency fuelling, special event fuelling, and CNG station site trials. Product pictures (samples only complete line of equipment available): CNG compressor on skid CNG high-pressure storage system CNG dispenser for vehicle fuelling Self-contained, mobile CNG fuelling system (Malaysia)
Market Overview While IMW has provided products and services to over 24 countries worldwide, particularly strong markets exist in several key areas including Colombia, Bangladesh, Pakistan, Malaysia, and China. Sales in the last 7 years have surpassed the previous 19 years of CNG market activity and IMW has been able to secure more multiple-station customers. In addition to new product sales, IMW has established subsidiary service companies in Colombia, Bangladesh and China to help support our growing customer base. At present, our target CNG users include gas utility companies, transit bus companies, taxi companies, government fleets, major oil/gas companies, oil/gas EPC companies, power generation companies, and private CNG station operators. IMW has a long established record of manufacturing excellence and international export experience and, as an ISO9001:2008 certified manufacturer, is recognized as a world leader in the development and deployment of CNG equipment and complete fuelling systems. As global markets continue to emerge and change, IMW is developing adaptive strategies to maximize existing and future potentials for revenue production and long-term stability. The present status of energy security and transportation issues worldwide indicates a growing market for IMW s products and services. We continue to manage our production capabilities to meet this growth while maintaining our high standards of quality. More recently, renewed interest in the development of CNG infrastructure for North America brings the promise of increased fuel savings and the reduction of greenhouse gases closer to home. CNG for transportation is seen as the highest and best value use for the abundant shale gas reserves recently made available. IMW is strategically aligned with a number of Canadian companies offering complementary equipment and services in order to best serve the growing demand for vehicular and stationary CNG fuelling applications, including those aimed at converting organic waste to biogas. Please feel free to contact us with any questions you might have at imw@info.ca or look us up at www.imw.ca.
IMW Industries Ltd. 43676 Progress Way, Chilliwack, BC, Canada V2R 0C3 (604) 795-9491 Fax (604) 792-3806 www.imw.ca Printed in Canada