by Armin Amio
October 7, 2015
Surrey, British Columbia – Natural gas is regarded as a clean fossil fuel and relatively inexpensive compared with most fossil fuels like diesel or kerosene.
While there are moves to replace fossil fuels with more sustainable alternatives, most experts believe that these cannot be replaced in bulk anytime soon. Power generation and global commerce continue to depend on fossil fuels. The use of biofuels in the transportation sector maybe growing, these can only be competitive when subsidized. Synthetic gas fuels have also gained acceptance, but these are not available in large volumes that can support global energy requirements.
At present, the country’s only source of indigenous natural gas is from the Malampaya gas field, located in offshore northwest Palawan. This is operated by Shell Philippines Exploration Corp. on behalf of other consortium members, Chevron and PNOC- Exploration.
FortisBC facility in Tilbury, Vancouver, B.C. Photo courtesy of FortisBC
The only users of this indigenous natural gas are First Gen, through its subsidiary First Gas, and Kepco’s 1,200-megawatts (MW) llijan plant, all located in the province of Batangas.
First Gen, a leading power generation company in the country, pioneered the use of this indigenous natural gas through its two power plants — the 1,500-MW Santa Rita and 500-W San Lorenzo. The company is also expanding its power generation assets with the scheduled completion this year of its 97-MW Avion plant that will run on aeroderivative fuels and another 414-MW San Gabriel plant that is expected to be completed by 2016. The latter can run on natural gas.
Like all fossil fuels, natural gas deposits are limited. In the case of Malampaya field, its supply is expected to last only until 2025.
Liquified natural gas (LNG) is seen as a possible stop-gap solution, until a more permanent, renewable and cheaper source of fuel for the power plants is discovered.
LNG is a clear, colorless, non-toxic liquid — created by cooling the gas to a liquid — so it can be transported and stored more easily than natural gas because it occupies up to 600 times less space.
When LNG reaches its destination, it is returned to its gas state at regasification facilities and then piped to homes, businesses and industries.
First Gen is planning to build an LNG facility in Batangas. The said facility will allow the importation of natural gas — currently in abundant supply in North America and Europe through positive technological developments such as shale gas production.
According to power-eng.com around one-third of the natural gas internationally traded is transported in a form of liquefied natural gas (LNG), and this fraction is projected to grow.
LNG is a mixture of gases, predominantly methane, liquefied at a temperature of -163 °C. The feedstock gas is first processed to remove hydrogen sulfide (H2S), carbon dioxide (CO2) and water vapor (H2O) to desirable levels by absorption, adsorption and separation processes. These contaminants are undesirable as they will freeze in the very low temperature cooling processes. H2S is also a toxic, corrosive, acid (sour) gas; CO2 is also acidic (sour) and corrosive in the presence of water.
Heavier fractions are removed as well, including propane, butane and ethane commonly referred to as natural gas liquids (NGLs).
Aeroderivatives can be fueled with either LNG or NGLs. Re-gasified LNG can be used in either pre-mixed, dry low emissions or diffusion flame combustion systems with no turbine/package modifications required. NGLs may also be utilized, and pending the ratios of the hydrocarbons present, may be used in either gas or liquid form.
ENVIRONMENT FRIENDLY FUEL
The resulting fuel derived from LNG after regasification is extremely pure. It is considered as the cleanest fossil fuel with a very low carbon emission. The carbon emission of a combined cycle natural gas-fired power plant hovers at a little over a third of a ton for every megawatt-hour of electricity generated. In contrast, a typical coal-fired power plant emits to the atmosphere almost one ton of carbon for every megawatt-hour of electricity generated.
A major player in LNG trading is Fortis BC, Inc., Canada’s largest private utility company. Its natural gas unit serves approximately 920,000 customers in over 125 communities. Rates in different areas vary by over 60%. Its service territory includes Lower Mainland, Vancouver Island, and the southern interior of the province. The company owns and operates approximately 47,500 kilometers of natural gas transmission and distribution pipelines.
Together with the electricity unit, FortisBC (natural gas) delivers over 20% of total energy consumed in British Columbia and serves more than 1.1 million customers in more than 135 communities.
In addition to using LNG for power use, natural gas can also be applied for the transportation sector. More and more fleet owners and operators across North America are said to be switching to natural gas so they can save on fuel costs and shrink their environmental footprint.
With more than 16.7 million natural gas vehicles in use worldwide, it’s already a conventional fuel choice.
Fortis said LNG fuel costs have historically been 25% to 40% less than diesel, while greenhouse gas emissions are reduced by 20% to 30%
According to operators, natural gas engines run quieter compared with diesel-fueled engines, benefiting drivers and the communities they operate in. source
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