Lng: An eco-friendly cryogenic fuel for sustainable development
Abstract
As the demand of natural gas has sharply increased in the last two decades at the global level, the transportation of natural gas from different parts (gas producing to the consuming areas) of the world has become more significant. Liquefaction of natural gas provides a safer and economical alternative for transportation and also increases its storage capabilities. The liquefaction process requires the natural gas to be cooled using various methods of cryogenic processes and also be depressurized to atmospheric conditions for easier and safer storage. LNG transported in cryogenic vessels offers several advantages over pipeline transport of natural gas especially when the gas consuming areas are far away from the gas producing areas. Moreover, LNG as an automobile fuel has a definite edge over other fuels.
This article presents an overview on the characteristics of LNG, present state of affairs of LNG, its import from overseas, CNG vs. LNG as an automobile fuel, eco-friendliness of natural gas fuel, etc. It also discusses the potential of natural gas production from different sources.
Highlights
► The use of LNG has gained much recognition globally. ► LNG is quite different from CNG & LPG at similar condition of temperature & pressure. ► LNG is superior to gasoline and oil in terms of calorific value. ► The world’s total NG reserves are 6254.364 Tcf located in different regions. ► LNG offers GHG reductions & produces fewer emissions compared to coal & oil.
Abbreviations
L-NGV, liquefied natural gas vehicle; LNG, liquefied natural gas; CNG, compressed natural gas; LPG,liquefied petroleum gas; LFG, landfill gas; MT, million tone; MMTA, million metric tone per annum; MJ/m3,megajoule per cubic meter; GGE, gasoline per gallonequivalent; DGE, diesel per gallonequivalent; NGV,natural gas vehicles; LDV, light duty vehicles; GVR, gas vehicle report; PPG, pound per gallon; PPB,parts per billion; bpd, barrels per day; CO2, carbon dioxide; CO, carbon monoxide; NOx, nitrogen oxides;SOx, sulfur oxides; GHG, green house gasKeywordsCompressed natural gas; Liquefied natural gas; Cryogenic fuel; Green house gases; Pollution prevention
1. Introduction
The worldwide energy demand is increasing continuously and is projected to grow by an average of 1.2% per year [1]. Owing to the abundance and the availability of fossil fuels resources, it can be estimated that they will continue to play a significant role in the world’s energy economy. Fossil fuels currently provide about 85% of the world’s commercial energy needs.
It has been anticipated that China [2], which today meets almost 90% of its power needs with coal, will see its energy demand for power generation more than double by the next century, surpassing US demand by more than one-third [2] and [3]. Currently, automobile is responsible for more than half of total oil demand and this demand is expected to grow substantially. Demand in developed countries is expected to be essentially flat in contrast to developing countries as economic growth and rising prosperity leads to a dramatic increase in personal vehicles.
At the same time, global CO2 emissions are projected to rise by close to 30% between 2005 and 2030, even with improved energy efficiency and growth in nuclear and renewable energies [1].
Therefore, in order to fulfill the increasing energy demand and to reduce the environment CO2% a drive to find alternative fuels [4] to replace hydrocarbons such as diesel and petrol has resulted in a plethora of different fuels—few of which are commercially available in significant quantities. Natural gas is one of them which is widely available and renewable (through the production of biogas or bio-methane), offers greenhouse gas reductions and produces fewer emissions compared to other traditional and alternative fuels. Natural gas can be used either as compressed natural gas (CNG), liquefied natural gas (LNG) or even blended with hydrogen. The use of natural gas vehicles (NGVs) also facilitates energy security and energy diversity.
Thus, natural gas has emerged as the most preferred fuel due to its inherently environmental benignity, greater efficiency and cost effectiveness. For long distance transportation of natural gas, natural gas liquefaction has many advantages over pipeline transportation. A comparison of world’s natural gas supplies via pipeline vs. LNG is represented in Fig. 1.
Fig. 1.
Comparison of natural gas supply in the form of LNG vs. pipeline.
Figure options
Like all natural gases, LNG is cleaner than coal and oil, and offers an opportunity to diversify energy supplies. Hence, within the gas market the use of LNG has gained much recognition globally and it is the right moment to review the status of LNG development with regard to various resources of natural gas, storage, transportation, utilization of LNG in different sectors and to trace the desirability of LNG technology.