Читать книгу Process Intensification and Integration for Sustainable Design - Группа авторов - Страница 15

The high availability of natural gas, generated as a result of the increasing production of shale gas, has caused a noticeable drop of its price in the United States. Moreover, the ability to extract natural gas from deposits that are not associated to crude oil reservoirs has uncoupled natural gas and crude oil prices [1]. These facts have contributed to what has been defined as the new era of cheap natural gas, in which it has been priced consistently under US$5 per million Btu for almost a decade in the United States [15]. In particular, natural gas prices in 2019 have shown a decrease from 3.18 at the beginning of the year to US$2.07 per million Btu in September [16]. Even more, in an extreme situation, producers at the Waha hub in the Permian basin in West Texas had to pay the pipeline to take the excess of gas, showing a negative US$9 in April, which contributed to an average price of only 73 cents per million Btu for the first eight months of 2019, compared with an average market price of US$2.10 in 2018 (which is also lower than the five year average from 2014 to 2018 of US$2.80) [17]. These trends create an opportunity for the development of technologies to transform shale/natural gas into value‐added chemicals. One additional point to consider is the increasing amount of liquefied natural gas that is being exported from the United States [18]. As this quantity grows, international natural gas prices may also get affected.

The main consumers of natural gas are the electricity generation industry, the residential sector, the industrial sector, and the chemical industry. Low natural gas prices have incentivized the electric power plants to switch from coal to natural gas, with an impact not only on the economy of these systems but also on the environment by reducing the total greenhouse gas emissions [1].

Another sector that has shown interest in switching from oil‐based feedstocks, such as naphtha or crude oil, to natural gas is the chemical industry. The availability of inexpensive natural gas and NGLs has boosted the chemical industry to create new plants for the production of value‐added chemicals using methane and NGLs as feedstock [5,19].