NEWS

15th june 2010 -
Ochre Energy expands regional network

Along with proposed terminals on the West Coast of Australia and the Gulf of Carpentaria, Ochre Energy is in discussions with suppliers and customers in the South East Asian region covering PNG, and Indonesia. From an LNG distribution point of view this area is geographically linked and ideal for domestic LNG distribution.

Natural gas is set to become one of the most important primary energy sources for the 21st century. Compared with other fossil fuels, gas is relatively clean with regards to air pollution and greenhouse gas emissions and has larger proven reserves.

It is expected to account for about 30% of total electricity generation by 2020. Similarly, its ratio for heating purposes and as transport fuel is growing rapidly. However, the main difficulty in conveying gas to the markets is its transport over long distances.

Liquefaction makes it possible to market important gas reserves located in remote areas, far away from consumer countries, as it reduces the volume: 1 litre of liquefied natural gas (LNG) corresponds roughly to 600 litres of natural gas. Hence, since its inception in the 1960s, LNG has grown significantly and makes a strong contribution to meeting the world’s energy needs: it now represents nearly a quarter of worldwide gas exports and worldwide production is expected to more than double from 2004 to 2010 and reach more than 300 million tonnes per annum.

LNG is a fast expanding energy sector and, although currently it is commonly evaporated and compressed into long-distance pipelines, new solutions are bringing LNG directly to off-pipeline customers, thus opening a new segment of application. LNG technology is constantly evolving to meet the increasing demand and dramatically reducing costs.

NATURAL GAS

Basic Data

Natural gas is primarily methane, with low concentrations of other hydrocarbons, water, carbon dioxide, nitrogen, oxygen and some sulphur compounds. In 2005, natural gas accounted for 23.5% of the global primary energy balance, in third position after oil (36.4%) and coal (27.8%) and before hydro electricity (6.3%) and nuclear energy (5.9%).

Since the 1980s, the amount of proven reserves has kept rising and was, at the end of 2005, estimated at around 180,000 billion m³, which equals 60 years of global consumption. Much of this gas is located in regions far from consuming markets. Worldwide production of natural gas is estimated as being around 2763 billion m³.

ENVIRONMENTAL DATA

Within the framework of the Kyoto Protocol, parties have agreed specific emissions reduction commitments and it is expected that greater use of cleaner energy will play an important role in meeting these commitments. These cleaner energies include natural gas and consequently LNG. Due to its chemical characteristics, natural gas is the cleanest burning fossil fuel because of its larger H2/C ratio. It produces fewer CO2 emissions and pollutants than either coal or fuel oil; data, calculated to enable comparison of CO2 emission rates from each fossil oil at the same heat power: the saving in CO2 emissions from fuel combustion for natural gas amounts to roughly 65% compared with coal and 25% compared with oil.

Fuel
Gas
Oil
Coal
CO2 emission rates (Mt of CO2/Mtoe1)
2.27
2.82
3.76
Comparison between CO2 emission rates2 (%)
0
+24.5
+65.8

1Mega tonnes oil equivalent
2 Based on natural gas rate

LNG PROPERTIES

Chemical data

LNG is a liquid form of the natural gas commonly used in industry and residential buildings. Natural gas is condensed by cooling it to about -161°C and typically the storage pressures range from 1.7 bars to 17.2 bars (170–1720kPa). LNG is odourless, non-toxic, non-corrosive and its density is about 450 kg/m³.

Safety Issues

Usually, LNG is not explosive in its liquid state and once it is heated and becomes gas, it is not explosive if it is unconfined. Natural gas is flammable when it exists at a 5 to 15% concentration in the air. This range is much narrower than that of hydrogen (4 to 96%) or gasoline (1 to 99%). Importantly, the auto-ignition temperature, 537°C, is much higher than that of diesel fuel (248°C).

Handling LNG introduces potential safety hazards in terminals and LNG carriers. There are four typical risks: flammable vapour cloud dispersions, vapour cloud explosions, pool fires and rapid phase transition. These risks and appropriate measures are addressed in industry standards.

ADVANTAGES OF LNG

  1. LNG has very low particulate emissions because of its low carbon to hydrogen ratio.
  2. There are negligible evaporative emissions, requiring no relevant control.
  3. Due to its low carbon-to-hydrogen ratio, it produces less carbon dioxide per GJ of fuel than diesel.
  4. It has low cold-start emissions due to its gaseous state.
  5. It has extended flammability limits, allowing stable combustion at leaner mixtures.
  6. It has a lower adiabatic flame temperature than diesel, leading to lower NOx emissions.
  7. It has a much higher ignition temperature than diesel, making it more difficult to auto-ignite, thus safer.
  8. It contains non-toxic components.
  9. When released to the atmosphere and evaporated it is much lighter than air and thus it is safer than spilled diesel.
  10. Methane is not a volatile organic compound (VOC).
  11. Engines fuelled with natural gas in heavy-duty vehicles offer more quiet operation than equivalent diesel engines, making them more attractive for use in urban areas.
  12. It has nearly zero sulfur levels and, thus, negligible sulfate emissions.