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Natural Gas Beneficiation & Uses. Presented at the 6 th Zimbabwe Mining & Infrastructure Indaba by Paul Chimbodza (CEO) 8 October 2014. What is Natural Gas?.
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Natural Gas Beneficiation & Uses Presented at the 6th Zimbabwe Mining & Infrastructure Indaba by Paul Chimbodza (CEO) 8 October 2014
What is Natural Gas? • Natural gas is a fossil fuel formed when layers of buried plants, gases, and animals are exposed to intense heat and pressure over millions of years. The energy that the plants originally obtained from the sun is stored in the form of chemical bonds in natural gas. • Natural gas is a hydrocarbongasmixture consisting primarily of methane, but commonly includes varying amounts of other higher alkanes and even a lesser percentage of carbon dioxide, nitrogen, and hydrogen sulfide. • Natural gas is an energy source often used for heating, cooking, and electricity generation. It is also used as fuel for vehicles and as a chemical feedstock in the manufacture of plastics and other commercially important organic chemicals. (Wilkepedia)
Typical composition of Natural Gas • Methane CH4 70-90% • Ethane C2H6 • Propane C3H8 0 - 20% • Butane C4H10 • Carbon Dioxide CO2 0 - 8% • Oxygen O2 0 - 0.2% • Nitrogen N2 0 - 5% • Hydrogen Sulphide H2S 0 - 5% • Rare gases A, He, Ne, Xe trace
World natural gas supply and demandSource: BP 2006 Annual Statistic Review
Natural Gas Nomenclature • Hydrocarbons - Coal, Oil, Gas, CBM, shale gas • LPG - Liquefied Petroleum Gas • LNG - Liquid Natural Gas • CNG - Compressed Natural Gas
Uses of Natural Gas • 22% of energy in the USA is gas powered • Electricity generation • Manufacturing sector • Fertiliser • Residential use • Motor vehicles • Substitute for diesel and coal powered plants
Markets and Infrastructure • Zimbabwe sedimentary basins proximal to existing and future pipeline infrastructure for the domestic and export markets • Numerous regional markets exist to monetise oil and gas in a starved market • Southern Africa power crisis affecting growth in the region amidst a huge push to adopt gas as an alternate energy source to coal • POTENTIAL GAS MARKETS • Hwangepower station • Pande-Temane gas pipeline to South Africa • Feruka and Harare refineries • Sable Chem ammonia plant • Rovuma basin LNG plants • IPP exports to any country within Southern Africa through the SAPP Rovuma Basin gas discoveries Pande/Temane gas fields
Electricity Power generation Natural gas continues to be the fuel of choice in many regions of the world in the electric power and industrial sectors due to its significant price discount relative to oil and its lower carbon intensity compared to coal. The development of natural gas resources from shale gas and other sources in the United States over the past few years has seen significant reduction of energy prices which has increased industrial competitiveness substantially. Discovery of a commercial natural gas resource will provide Zimbabwe with a means to generate base load power supply at substantially shorter lead times and cost compared to coal-fired generation plants.
Fertiliser Production • Natural gas is a major feedstock for the production of ammonia, via the Haber process, for use in fertilizer production. • Natural gas is first cleaned from sulfur, and then mixed with heated water vapor and supplied to the reactor, where it passes through catalyst beds. This stage is called primary reforming or gas-vapor conversion. A gas mixture composed of hydrogen, methane, carbon dioxide (СО2), and carbon oxide (СО) exits from the reactor. • Then, this mixture is sent to secondary reforming (gas-vapor conversion), where it is mixed with atmospheric oxygen, vapor, and nitrogen in proper proportions. At the next stage, CO and CO2 are removed from the mixture. Then, a mixture of hydrogen and nitrogen is sent to ammonia synthesis. • Ammonia as such is a fertilizer; it is also used as a coolant in refrigerating units and as a feedstock for production of nitrogen compounds, such as nitric acid, ammonia nitrate, and carbamide.
Domestic Household Use • Natural gas fired stoves can generate temperatures in excess of 1100 °C (2000 °F) • Independent reticulation piping to supply homes, where it is used for many purposes including stoves, ovens, geysers, dryers, central heating and cooling . • Compressed natural gas (CNG) is used in homes without connections to piped-in public utility services, or with portable grills. • However, as CNG costs more than LPG, LPG (propane) is the dominant source of home gas.
Gas to Liquids (GTL) • Liquid fuels can also be produced from natural gas using the gas-to-liquid technology (GTL). • Liquid hydrocarbons were first produced from synthesis gas by German chemists Franz Fischer and Hans Tropsch in 1923. • They used coal as a source of hydrogen at that time, though. Currently, different versions of the Fischer-Tropsch method are applied in many marketed processes for conversion of gas into liquid hydrocarbons. • Since natural gas is a quite inert product, it is first virtually always converted into a more reactive gas-vapor mixture, the so-called synthesis gas (mixture of CO and Н2). • Gas to Liquid products include, synthetic oil, diesel fuel, as well as lubricants and paraffins.
LNG (Liquefied Natural Gas) • Natural gas deposits are usually found in remote areas from end-users and there is need for transportation either by natural gas piping or by LNG vessels • Liquefied natural gas, or LNG, is natural gas that has been supercooled to -162 degrees Celsius and condenses into a liquid. When in liquid form, natural gas takes up to 600 times less space than in its gaseous state, which makes it feasible to transport over long distances. • For natural gas to be liquefied all impurities must be removed such as: - Sulfur, carbon dioxide and mercury which are corrosive to LNG equipment - Water, which could freeze and cause equipment blockage - Heavier hydrocarbons which could also freeze like water • LNG is odorless, colorless, non-corrosive and non-toxic. Its weight is less than one-half that of water • LNG is not stored under pressure. If the tank is ruptured, there is no massive release of energy and thus no explosion. • For an explosion to occur, LNG must first return to its gaseous state and then the natural gas vapors must accumulate in a confined space in a perfect mixture of 5 to 15 percent of gas in air, and encounter an ignition source.
LNG –Regasification- Liquefied natural gas (LNG) offloaded from the ship- moving it into cold storage tanks and then regasifying it back into natural gas to send to market. - The grey lines represent natural gas, and the yellow lines represent LNG - LNG losses due contact with warmer air in the top of the ship containers and in the LNG storage tanks. - This natural gas is siphoned out of the tanks and moved into the pipeline
LNG Value chain( $7 to $14 billion dollars of investment from start to finish)
LPG (Liquefied Petroleum Gas) • Liquefied petroleum gasor liquid petroleum gas (LPG or LP gas), also referred to as simply propane (C3H8), or butane(C4H10) , is a flammable mixture of hydrocarbon gases used as a fuel in heating appliances, cooking equipment, and vehicles. • LPG is composed primarily of propane and butane, while natural gas is composed of the lighter methane and ethane • LPG is prepared by refiningpetroleum or "wet" natural gas, • It was first produced in 1910 by Dr. Walter Snelling, and the first commercial products appeared in 1912. It currently provides about 3% of all energy consumed • Burns relatively cleanly with no soot and very few sulfur emissions. • Calorific value of 46.1 MJ/kg compared with 42.5 MJ/kg for fuel oil-and 43.5 MJ/kg for premium grade petrol (gasoline). • LPG boiling point is below room temperature & will evaporate quickly at normal temperatures and pressures • Stored in high pressure cylinders of varied sizes.
CNG – Compressed Natural Gas • Compressed Natural Gas(CNG) is Methane gas stored at high pressure and can be used in place of gasoline (petrol), Diesel fuel and propane/LPG. • CNG combustion produces fewer undesirable gases than the fuels mentioned above. • CNG is made by compressing natural gas (which is mainly composed of methane, CH4), to less than 1 percent of the volume it occupies at standard atmospheric pressure. • Used in traditional gasoline/internal combustion enginevehicles that have been modified or in vehicles which were manufactured for CNG use, either alone ('dedicated'), with a segregated gasoline system to extend range (dual fuel) or in conjunction with another fuel such as diesel (bi-fuel).
CNG for Natural Gas Vehicles • Compressed Natural Gas as a vehicle fuel is much cheaper and environmentally cleaner than petroleum products. • CNG is a cleaner alternative to other automobile fuels such as gasoline (petrol) and diesel. • Compressed (or pressurized) methanecosts half as much as petrol with the octane number of 76; extends the service life of engine; and can improve the urban ecology • By the end of 2012 there were 17.25 million natural gas vehicles worldwide, led by Iran (3.3 million), Pakistan (3.1 million), Argentina (2.18 million), Brazil (1.73 million), India (1.5 million), and China (1.5 million).
LNG in Aviation • Russianaircraft manufacturer Tupolev is currently running a development program to produce LNG- and hydrogen-powered aircraft.The program has been running since the mid-1970s, and seeks to develop LNG and hydrogen variants of the Tu-204 and Tu-334 passenger aircraft, and also the Tu-330 cargo aircraft. • It claims that at current market prices, an LNG-powered aircraft would cost 5,000 roubles (~ $218/ £112) less to operate per ton, roughly equivalent to 60 per cent, with considerable reductions to carbon monoxide, hydrocarbon and nitrogen oxide emissions. • The advantages of liquid methane as a jet engine fuel are that it has more specific energy than the standard kerosene mixes do and that its low temperature can help cool the air which the engine compresses for greater volumetric efficiency, in effect replacing an intercooler. Alternatively, it can be used to lower the temperature of the exhaust.
Paint, Glue and Vinegar • Methanol (CH3OH) is produced from natural gas under a scheme similar to the Fischer-Tropsch process. It is used as an agent for preventing hydrate plugs that are formed in pipelines at low temperatures. Methanol can also become a feedstock for manufacturing more complex chemical substances: formaldehyde, insulation materials, varnishes, paints, glues, fuel additives, and acetic acid.
Natural Gas prices in US dollars per million BTUs ($/mmbtu).(Henry Hub)mmbtu = 293kwh = US$29 equivalent (@10c/kwh)
Conquering the new Zimbabwean hydrocarbons frontier is going to need collective effort by all players
