Chemical Engineering Industries #1X: LNG
Last time in this series I supposedly talked about oil and gas industry. Key word: supposedly. Problem is that the script isn’t complete, so much so that gas industry which is technically a word in “oil and gas” got omitted.
Right, let’s get this straight: gas industry, also called natural gas industry for long due to the natural formation of the gas, is an industry dedicated to refine gases from oil and gas wells into separated products of C1 to C5 hydrocarbons (methane, ethane, ethylene, propane, propylene, butane, and condensate). To achieve that, several steps would be needed, such as impurities removal (water, carbon dioxide, sulfur compounds, and mercury), refrigeration and liquefaction, transportation, and storage. If the product is immediately shipped by pipe in a gas network, regasification may be needed.
Because natural gas is lighter, more volatile, and more flammable, it is used as a source of cleaner fuel compared to oil and coal (a sign being blue flame instead of red). Natural gas products, due to its molecular composition, can also be used as feedstock for petrochemical industries, such as urea and plastic. Please stay tuned for the next part of this series.
Natural gas, historically, is very much in sync with petroleum. However, in the beginning (well, still happening actually) the associated gas isn’t utilized very much and instead discarded through flaring system. Nonassociated gas, on the other hand, has actually been used as a source of fuel since 1917 in Virginia, USA and since 1977 in Indonesia with plants in Bontang and Arun.
One main difference in gas refinery compared to petroleum refinery is the raw material. Overall, gas sources are divided in two: associated and nonassociated (see last paragraph). Associated gas is a byproduct of oil extraction, whereas nonassociated gas is extracted directly from gas wells. Associated gas commonly contains less than 10% in gas while nonassociated gas contains methane as majority component even though in practice carbon dioxide also gets in most of the time.
After production, LNG has to be stored in a container capable of blocking outside heat into the container to keep the LNG cold. However, inevitably some of the LNG will evaporate. This vapor is called boil-off gas which would be used for refrigeration systems so that the other LNG can retain their temperature or used for LNG carrier fuel.
In general, natural gas business is very much tied to the petroleum industry, so the key players are usually the same: Gazprom, Sinopec, Pertamina, bp, and such. I wanted to talk about general industry worth, however for scale Gazprom alone booked a revenue of US$58 billion in 2019. Natural gas production itself globally reached 246 MTPA in 2014.
All in all, natural gas industry produces separated hydrocarbons ranging from one carbon to five carbons with methane as the main composition. The products can be used as cleaner fuel or petrochemical feedstock. Natural gas can be sourced from oil wells as associated gas or from gas wells as nonassociated gas with nonassociated gas dedicated fully to fuel generation. First industrial natural gas production was in 1917 and has developed to be a billion-dollar industry.
