Renewable natural gasRenewable natural gas (RNG), also known as biomethane or sustainable natural gas (SNG), is a biogas which has been upgraded to a quality similar to fossil natural gas and has a methane concentration of 90% or greater. By removing CO2 and other impurities from biogas, and increasing the concentration of methane to a level similar to fossil natural gas, it becomes possible to distribute RNG to customers via existing gas pipeline networks. RNG can be used in existing appliances, including vehicles with natural gas burning engines (natural gas vehicles).
Economic liberalismEconomic liberalism is a political and economic ideology that supports a market economy based on individualism and private property in the means of production. Adam Smith is considered one of the primary initial writers on economic liberalism, and his writing is generally regarded as representing the economic expression of 19th-century liberalism up until the Great Depression and rise of Keynesianism in the 20th century. Historically, economic liberalism arose in response to feudalism and mercantilism.
Combinatorial optimizationCombinatorial optimization is a subfield of mathematical optimization that consists of finding an optimal object from a finite set of objects, where the set of feasible solutions is discrete or can be reduced to a discrete set. Typical combinatorial optimization problems are the travelling salesman problem ("TSP"), the minimum spanning tree problem ("MST"), and the knapsack problem. In many such problems, such as the ones previously mentioned, exhaustive search is not tractable, and so specialized algorithms that quickly rule out large parts of the search space or approximation algorithms must be resorted to instead.
Program optimizationIn computer science, program optimization, code optimization, or software optimization, is the process of modifying a software system to make some aspect of it work more efficiently or use fewer resources. In general, a computer program may be optimized so that it executes more rapidly, or to make it capable of operating with less memory storage or other resources, or draw less power. Although the word "optimization" shares the same root as "optimal", it is rare for the process of optimization to produce a truly optimal system.
Economic geographyEconomic geography is the subfield of human geography which studies economic activity and factors affecting them. It can also be considered a subfield or method in economics. There are four branches of economic geography. Economic geography takes a variety of approaches to many different topics, including the location of industries, economies of agglomeration (also known as "linkages"), transportation, international trade, development, real estate, gentrification, ethnic economies, gendered economies, core-periphery theory, the economics of urban form, the relationship between the environment and the economy (tying into a long history of geographers studying culture-environment interaction), and globalization.
Economic systemAn economic system, or economic order, is a system of production, resource allocation and distribution of goods and services within a society. It includes the combination of the various institutions, agencies, entities, decision-making processes, and patterns of consumption that comprise the economic structure of a given community. An economic system is a type of social system. The mode of production is a related concept.
Economic freedomEconomic freedom, or economic liberty, is the ability of people of a society to take economic actions. This is a term used in economic and policy debates as well as in the philosophy of economics. One approach to economic freedom comes from the liberal tradition emphasizing free markets, free trade, and private property under free enterprise. Another approach to economic freedom extends the welfare economics study of individual choice, with greater economic freedom coming from a larger set of possible choices.
Convex optimizationConvex optimization is a subfield of mathematical optimization that studies the problem of minimizing convex functions over convex sets (or, equivalently, maximizing concave functions over convex sets). Many classes of convex optimization problems admit polynomial-time algorithms, whereas mathematical optimization is in general NP-hard.
Natural gasNatural gas (also called fossil gas, methane gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like 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.
Synthetic fuelSynthetic fuel or synfuel is a liquid fuel, or sometimes gaseous fuel, obtained from syngas, a mixture of carbon monoxide and hydrogen, in which the syngas was derived from gasification of solid feedstocks such as coal or biomass or by reforming of natural gas. Common ways for refining synthetic fuels include the Fischer–Tropsch conversion, methanol to gasoline conversion, or direct coal liquefaction. The term 'synthetic fuel' or 'synfuel' has several different meanings and it may include different types of fuels.
