Natural gas is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane (97%) in addition to various smaller amounts of other higher alkanes. Traces of carbon dioxide, nitrogen, hydrogen sulfide, and helium are also usually present. Methane is colorless and odorless, and the second largest greenhouse gas contributor to global climate change after carbon dioxide. Because natural gas is odorless, odorizers such as mercaptan are commonly added to it for safety so that leaks can be readily detected.
Coalbed methane, coalbed gas, or coal seam gas (CSG) is a form of natural gas extracted from coal beds. In recent decades it has become an important source of energy in United States, Canada, Australia, and other countries.
Substitute natural gas (SNG), or synthetic natural gas, is a fuel gas (predominantly methane, CH4) that can be produced from fossil fuels such as lignite coal, oil shale, or from biofuels (when it is named bio-SNG) or using electricity with power-to-gas systems.
Coal liquefaction is a process of converting coal into liquid hydrocarbons: liquid fuels and petrochemicals. This process is often known as "Coal to X" or "Carbon to X", where X can be many different hydrocarbon-based products. However, the most common process chain is "Coal to Liquid Fuels" (CTL).
Coal pollution mitigation, sometimes labeled as clean coal, is a series of systems and technologies that seek to mitigate health and environmental impact of burning coal for energy. Burning coal releases harmful substances that contribute to air pollution, acid rain, and greenhouse gas emissions. Mitigation includes precombustion approaches, such as cleaning coal, and post combustion approaches, include flue-gas desulfurization, selective catalytic reduction, electrostatic precipitators, and fly ash reduction. These measures aim to reduce coal's impact on human health and the environment.
Underground coal gasification (UCG) is an industrial process which converts coal into product gas. UCG is an in-situ gasification process, carried out in non-mined coal seams using injection of oxidants and steam. The product gas is brought to the surface through production wells drilled from the surface.
An integrated gasification combined cycle (IGCC) is a technology using a high pressure gasifier to turn coal and other carbon based fuels into pressurized gas—synthesis gas (syngas). It can then remove impurities from the syngas prior to the electricity generation cycle. Some of these pollutants, such as sulfur, can be turned into re-usable byproducts through the Claus process. This results in lower emissions of sulfur dioxide, particulates, mercury, and in some cases carbon dioxide. With additional process equipment, a water-gas shift reaction can increase gasification efficiency and reduce carbon monoxide emissions by converting it to carbon dioxide. The resulting carbon dioxide from the shift reaction can be separated, compressed, and stored through sequestration. Excess heat from the primary combustion and syngas fired generation is then passed to a steam cycle, similar to a combined cycle gas turbine. This process results in improved thermodynamic efficiency, compared to conventional pulverized coal combustion.
The energy policy of India is to increase the locally produced energy in India and reduce energy poverty, with more focus on developing alternative sources of energy, particularly nuclear, solar and wind energy. Net energy import dependency was 40.9% in 2021-22.
China is both the world's largest energy consumer and the largest industrial country, and ensuring adequate energy supply to sustain economic growth has been a core concern of the Chinese Government since the founding of the People's Republic of China in 1949. Since the country's industrialization in the 1960s, China is currently the world's largest emitter of greenhouse gases, and coal in China is a major cause of global warming. However, from 2010 to 2015 China reduced energy consumption per unit of GDP by 18%, and CO2 emissions per unit of GDP by 20%. On a per-capita basis, China was only the world's 51st largest emitter of greenhouse gases in 2016. China is also the world's largest renewable energy producer, and the largest producer of hydroelectricity, solar power and wind power in the world. The energy policy of China is connected to its industrial policy, where the goals of China's industrial production dictate its energy demand managements.
Shale gas is an unconventional natural gas that is found trapped within shale formations. Since the 1990s a combination of horizontal drilling and hydraulic fracturing has made large volumes of shale gas more economical to produce, and some analysts expect that shale gas will greatly expand worldwide energy supply.
Since 2013, total primary energy consumption in India has been the third highest in the world after China and United States. India is the second-top coal consumer in the year 2017 after China. India ranks third in oil consumption with 22.1 crore tons in 2017 after United States and China. India is net energy importer to meet nearly 47% of its total primary energy in 2019.
China is the largest producer and consumer of coal and coal power in the world. The share of coal in the Chinese energy mix declined to 55% in 2021 according to the US Energy Information Agency.
The milestones for carbon capture and storage show the lack of commercial scale development and implementation of CCS over the years since the first carbon tax was imposed.
Hydromethanation, [hahy-droh- meth-uh-ney-shuhn] is the process by which methane is produced through the combination of steam, carbonaceous solids and a catalyst in a fluidized bed reactor. The process, developed over the past 60 years by multiple research groups, enables the highly efficient conversion of coal, petroleum coke and biomass into clean, pipeline quality methane.
The environmental impact of the energy industry is significant, as energy and natural resource consumption are closely related. Producing, transporting, or consuming energy all have an environmental impact. Energy has been harnessed by human beings for millennia. Initially it was with the use of fire for light, heat, cooking and for safety, and its use can be traced back at least 1.9 million years. In recent years there has been a trend towards the increased commercialization of various renewable energy sources. Scientific consensus on some of the main human activities that contribute to global warming are considered to be increasing concentrations of greenhouse gases, causing a warming effect, global changes to land surface, such as deforestation, for a warming effect, increasing concentrations of aerosols, mainly for a cooling effect.
Energy in Australia is the production in Australia of energy and electricity, for consumption or export. Energy policy of Australia describes the politics of Australia as it relates to energy.
The Kemper Project, also called the Kemper County energy facility or Plant Ratcliffe, is a natural gas-fired electrical generating station currently under construction in Kemper County, Mississippi. Mississippi Power, a subsidiary of Southern Company, began construction of the plant in 2010. The initial, coal-fired project was central to President Obama's Climate Plan, as it was to be based on "clean coal" and was being considered for more support from the Congress and the incoming Trump Administration in late 2016. If it had become operational with coal, the Kemper Project would have been a first-of-its-kind electricity plant to employ gasification and carbon capture technologies at this scale.
Coal gasification is a process whereby a hydrocarbon feedstock (coal) is converted into gaseous components by applying heat under pressure in the presence of steam. Rather than burning, most of the carbon-containing feedstock is broken apart by chemical reactions that produce "syngas." Syngas is primarily hydrogen and carbon monoxide, but the exact composition can vary. In Integrated Gasification Combined Cycle (IGCC) systems, the syngas is cleaned and burned as fuel in a combustion turbine which then drives an electric generator. Exhaust heat from the combustion turbine is recovered and used to create steam for a steam turbine-generator. The use of these two types of turbines in combination is one reason why gasification-based power systems can achieve high power generation efficiencies. Currently, commercially available gasification-based systems can operate at around 40% efficiencies. Syngas, however, emits more greenhouse gases than natural gas, and almost twice as much carbon as a coal plant. Coal gasification is also water-intensive.
Natural gas was the United States' largest source of energy production in 2016, representing 33 percent of all energy produced in the country. Natural gas has been the largest source of electrical generation in the United States since July 2015.
China's greenhouse gas emissions are the largest of any country in the world both in production and consumption terms, and stem mainly from coal burning, including coal power, coal mining, and blast furnaces producing iron and steel. When measuring production-based emissions, China emitted over 14 gigatonnes (Gt) CO2eq of greenhouse gases in 2019, 27% of the world total. When measuring in consumption-based terms, which adds emissions associated with imported goods and extracts those associated with exported goods, China accounts for 13 gigatonnes (Gt) or 25% of global emissions. According to the Carbon Majors Database, Chinese state coal production alone accounts for 14% of historic global emissions.
