The possibility of alleviation of methane and carbon dioxide levels in the atmosphere are of major global interest. One of the alternatives that attracts much scientific attention is their chemical utilization, especially because both of these gases are components of the biogas. Thus, the rapid and extensive shale gas development makes them abundant raw materials. The development of an effective catalytic process that could be scaled-up for industrial purposes remains a great challenge for catalysis. As well, understanding of the mechanisms of molecular activation and the reaction pathways over active centers on heterogeneous catalysts needs to be advanced. It has been shown that biogas is a very interesting source of renewable energy. Because of its elevated methane content, biogas has excellent potential, as reflected in its year-over-year rise in production. This is because its manufacturing promotes the use of organic waste, prevents uncontrolled dumping and minimizes atmospheric methane and carbon dioxide emissions. Moreover, its use as an energy source is in some cases an alternative to fossil fuels and can help to minimize energy dependence. Another aspect of interest is that it can be used in situ, allowing agro-livestock farms or small industrial plants to achieve energy self-sufficiency.
The use of adsorbed natural gas (ANG) as a transportation fuel is a relatively cleaner alternative compared to that of gasoline and is important from the perspective of environmental safety. However, unlike gasoline and diesel, natural gas requires compression, liquefaction, and adsorption techniques for its storage, as it has a very low volumetric energy density. Among all storage techniques, adsorption-based natural gas (ANG) storage is considered as more economical and relatively safe technology due to its mild temperature and pressure conditions for the storage. This chapter will summarize the recent advances in the area of ANG with reference to various synthetic storage materials recently developed for the purpose and their efficiency towards storage and deliverability of natural gas. Particular emphasis will be given to adsorbents based on porous carbon materials, metal organic frameworks, and covalent organic frameworks for the said application. The synthetic procedure for the above adsorbents, followed by their efficiency to store and deliver natural gas, will be discussed. Finally, in the conclusion, the future scope of the technology will be summarized.
In the 1970's natural gas was written off in the thinking of many energy planners. It was a "buggy-whip" industry. Environmental impacts are of concern both at the point of end-use energy consumption and at all points in the chain of production, processing and distribution. The environmental advantages of natural gas relative to other energy forms are equally impressive from either perspective. As a rule, supply and utilization systems based on gaseous fuels require substantially less initial capital investment than alternative energy systems. Whereas two-thirds of the energy input to conventional fossil fuel boiler systems is normally lost to the environment, the waste heat from the gas turbine in a combined-cycle unit is captured and utilized. Thus, combined-cycle system efficiency is in the 45 percent range or above. By 1990, approximately 25 percent of all fossil-fueled generating capacity will be at least 30 years old.
A revolution is underway in electricity generating technology that may soon radically transform the power industry in both industrial and developing countries. This revolution involves not an exotic new technology, but rather an upgrading of the familiar but little-used gas turbine, the neglected step-sister of the steam turbine in power generation. The electric power industry needs a technological revolution, since business-as-usual is becoming increasingly untenable. Public concerns about nuclear power risks and the environmental problems posed by fossil fuel power plants have made electric utility planning more and more difficult. The historical attraction of the gas turbine for utilities has been its low cost, $300 per kW22 or less, a small fraction of the cost of coal or nuclear power plants. An early major milestone in the history of the gas turbine was the initiation of German and British programs in the mid-1930s to explore the use of gas turbines for aircraft propulsion.
This chapter presents an introduction to the terminology and definitions involved with the natural gas technology. The terminology and definitions applied to natural gas (and, for that matter, to other gaseous products and fuels) are extremely important and have a profound influence on the manner by which the technical community and the public perceive that gaseous fuel. For the purposes of this book, natural gas and those products that are isolated from natural gas during recovery (such as natural gas liquids, gas condensate, and natural gasoline) are introduced in the chapter. The chapter also introduces the reader to the history of natural as technology as well as to the uses of natural gas.
The term gas condensate (or condensate) is often applied to any liquid composed of low-boiling hydrocarbons produced from a gas well. However, the term condensate reservoir should be applied only to those reservoir situations in which condensate is formed in the reservoir because of retrograde behavior. Wet-gas reservoirs can always be treated as containing single-phase gas in the reservoir, while retrograde-condensate reservoirs may not. Wet-gas reservoirs generally produce low-boiling liquids with gravities similar to those for retrograde condensates. This chapter presents a description of the isolation and properties of gas condensate and where condensate fits into the oval area of natural gas.
As long as many countries have fossil fuel-based economies, fossil fuel combustion will lead to environmental problems. In addition, the venting or leaking of natural gas into the atmosphere can have a significant effect with respect to greenhouse gases because methane, the principal component of natural gas, is much more effective in trapping these gases than carbon dioxide. The exploration, production, and transmission of natural gas, as well, can have adverse effects on the environment. This chapter addresses the many environmental aspects related to the use of natural gas, including the environmental impact of natural gas relative to other fossil fuels and some of the potential applications for increased use of natural gas. These issues include: (1) greenhouse gas emissions, (2) smog, air quality, and acid rain, and (3) industrial and electric generation emissions.
This chapter discusses options available for running conventional gasoline and diesel fueled vehicles on alternative fuels based on natural gas. The alternatives examined are compressed natural gas (CNG), liquefied petroleum gases, i.e. propane and butane, methanol which is an alcohol fuel derived principally from natural gas, and synthetic gasoline and diesel fuels derived from natural gas. A CNG fueled vehicle must carry a load of roughly 2.8 kg for every liter of gasoline equivalent, while a liter of gasoline weighs only about 0.75 kg. There is thus a substantial weight penalty involved in the use of CNG which, in the case of a passenger car with a 75 liter gasoline tank, would amount to about 150 kg. The principal use of Liquefied Natural Gas is as a method of transporting natural gas from areas where it is abundant and cheap, to industrialized countries.
This chapter describes natural gas from its origin in the Earth to production, thereby confirming that any successful development project needs analytical monitoring at all aspects of the development. The well development is an essential part of the production process and is instituted immediately after exploration has located a reservoir that can economically produce natural gas. The properties of reservoir fluids can play a key role in the design and optimization of injection/production strategies and surface facilities for efficient reservoir management. The necessary properties are evident when the reservoir is first prepared for gas production through following categories: gas wells; well completion; wellhead; well treatment; and natural gas production. Knowledge of local geology, reservoir mineralogy, and environmental conditions allows developers as well as regulators and lawmakers to tailor regulations to meet the environmental needs, particularly to protect drinking water.
In addition to conventional natural gas, there are several types of unconventional gas resources that are currently produced and these are: (1) methane hydrates—natural gas that occurs at low temperature and high pressure regions such as the sea bed and is made up of a lattice of frozen water, which forms a cage around the methane; (2) biogas, which is a gas produced from various types of biomass; (3) coalbed methane—natural gas that occurs in conjunction with coal seams, coal gas, which is a gas produced by the thermal decomposition or gasification of coal; (4) flue gas, which is a gas from various industrial source that is sent up a flue for dispersal; (5) gas in geopressurized zones—natural underground formations that are under unusually high pressure for their depth; (6) gas in tight formations, which is a gas located in reservoirs in which the permeability is zero or, at best very low; (7) landfill gas, which is a gas produced by the decomposition of landfill materials; (8) manufactured gas, which is a fuel–gas mixture made from other solid, liquid, or gaseous materials, such as coal, coke, oil, or natural gas—examples are retort coal gas, coke oven gas, water gas, carbureted water gas, producer gas, oil gas, reformed natural gas, and reformed propane or liquefied petroleum gas; (9) refinery gas, also called petroleum gas, which is a gas that emanates from the top of a refinery distillation column or from any other refinery process; (10) shale gas, which is a gas that is recovered from shale formation; and (11) synthesis gas, also known as syngas, which is a mixture of carbon monoxide (CO) and hydrogen (H2) and is produced from a wide range of carbonaceous feedstocks. This chapter presents a description of the origin and properties of each of the nonconventional gases.
This chapter presents the various aspects of natural gas recovery, storage, and transportation. After recovery, natural gas that is scheduled to be transported and stored must meet specific quality measures so that the pipeline network (or grid) can provide uniform quality gas. Wellhead natural gas will contain other hydrocarbons, inert gases, and contaminants, which must be removed before the natural gas can be safely delivered to the high-pressure, long-distance pipelines that transport natural gas to consumers.
Many chemical and physical processes are available for processing or refining natural gas. However, there are many variables in the choice of refining sequence that dictate the choice of process or processes to be employed. In this chapter, several factors must be considered: (1) the types and concentrations of contaminants in the gas, (2) the degree of contaminant removal desired, (3) the selectivity of acid gas removal required, (4) the temperature, pressure, volume, and composition of the gas to be processed, (5) the carbon dioxide–hydrogen sulfide ratio in the gas, and (6) the desirability of sulfur recovery due to process economics or environmental issues. The focus of this chapter is a selection of the processes that are an integral part within the concept of production of a product (methane) suitable for sale to the consumer.
This chapter presents a description of the various categories of processes used for gas processing (also called gas cleaning and gas refining) which is necessary to produce the product that meets the various specifications. Gas processing is, in fact, an integrated system of unit processes that are used to remove objectionable products such as acid gases (e.g., carbon dioxide and hydrogen sulfide) and to separate natural gas into other useful gas streams. Thus gas processing is instrumental in ensuring that the natural gas intended for use is as clean and pure as possible, making it the clean burning and an environmentally sound energy choice.
This chapter explains some of the significant economic issues that energy policy makers face in planning natural gas development and consumption. Natural gas is one of several major energy resources, and the fundamental economic principles that govern the appraisal of any natural resource project apply to natural gas. The importance of these economic principles is that they help energy policy makers assess the cost and value of natural gas to the economy. Economic theory holds that, in order to provide an efficient allocation of resources, the price of a good should be equal to the marginal cost of expanding the output of the good so that it clears the market. To determine the marginal cost of supplying gas, economists and engineers in gas companies work closely following an iterative process to plan the system. For a number of developing countries, indigenous natural gas resources hold the key to reducing expensive reliance on oil.
Natural gas is an abundant resource with broad worldwide distribution. Given its inherent economic and environmental advantages, it may be considered underutilized. This situation is changing dramatically. Natural gas is emerging as a "fuel and raw material of choice" for coming decades, with important implications from a development perspective. North America and Western Europe would be the only areas where economically recoverable natural gas resources would remain in 2020 at maximum demand rates. The total in-place worldwide natural gas resource base, including sources not yet economically producible with technology, is several orders of magnitude greater. The Soviet policy of increased gas production and sales clearly offset any influence of slower international economic growth in the early 1980's. In fact, Soviet gas consumption continued to increase decisively, and it is clear that the other Eastern European countries continued to expand their use of gas rapidly.
The history of natural gas use extends into antiquity, but the history of gas processing is somewhat more recent. In fact, the history of gas processing is, of course, carefully intertwined with the development of gas use and gas technology. This chapter presents the history of gas processing using the evolution of the use and development of gas production technology. This includes reference to the original commercial gas industry that involved the production of gas from coal. It is from such an industry that the modern gas processing industry evolved.
The petrochemical sector is in the aftermath of the extensive restructuring that resulted from changes in raw material prices and increased availability, technological improvements, near market saturation for basic petrochemicals in developed countries, and the emergence of non-traditional producers as major partners in world trade. Nothing typifies more the turmoil of change that has affected the industry than the rapid changes in feedstock prices and availability. Within the petrochemical industry, natural gas liquids and naphtha have been by far the preferred feedstocks for ethylene synthesis. The growth rate in world chemical trade has been as extraordinary as the growth in chemical production. World trade of chemicals grew from $22 billion in 1970 to $216 billion in 1987, and of this an estimated 60% is for petrochemicals. Technological progress has been a key factor in the remarkable resilience of the petrochemical industry to changes in the conditions of the world market.
