A large mixed-integer linear program (MILP) and a much smaller nonlinear programming (NLP) approximation of the MILP, involving simulation and response surface estimation via regression analysis, are proposed to solve the problem of the optimal selection of natural gas supply contracts by local gas distribution utilities. Each potential supply source is characterized by several price and nonpri...

Crude oil plays an increasingly significant role in world economic development and also in the generation of wealth since nearly two-thirds of the world’s energy consumption comes from crude oil and natural gas. Worldwide consumption of crude oil exceeds $500 billion—roughly 10% of US GDP and crude oil is also the world’s largest and most actively traded commodity, accounting for about 10% of t...

This paper presents a case study based on a LCA (Life Cycle Assessment) research program of the silicon foundry sand (SFS) due to the large quantity of produced waste foundry sand (WFS). The foundry waste is a high priority sector within the growing European foundry industry. It is necessary to understand the full life cycle of the foundry waste in order to correctly identify magnitude and type...

flowing the uruguay round negotiations (1986-1994), the world trade system has evolved. on the basis of agreements of this round, world trade organization (wto) members have been obligated to decrease tariff obstacles, non-tariff restrains and trade supports. the use of trade liberalizing policies (tariff obstacles and non-tariff restrains) by members and observing countries has had significant...

Indonesia’s economic growth slowed modestly in 2001. That caused of response to the global economic slowdown, which reduced demand for the country’s export. Indonesia currently holds proven oil reserves of 5 billion barrels and has proven natural gas reserves of 92.5 trillion cubic feet (Tcf). Its is important to world energy markets and also holds a special position in international climate po...

This chapter reviews recent applications of computable general equilibrium (CGE) modeling in the analysis and evaluation of policies which affect interactions among multiple markets. At the core of this research is a particular approach to the data and structural representations of the economy, which we elaborate through the device of a canonical static multiregional model. We adapt and extend ...

Due to its significant advantages, natural gas, which forms an increasing share of world energy resources, has become one the important resources worldwide. When gas prices are analyzed around world, it is seen that price formulas depend on petroleum products. Natural in proportion increase There a simultaneous change same direction between oil and exchange rates. also determined depending subs...

Natural gas is often associated with nitrogen and heavy compounds. The Heavy components in the natural gas not only can feed downstream units, owing to the low temperature process may be formed solid as well. Therefore, heavy components separation can be a necessity and produce useful products. Virtually, all natural gases are containing nitrogen ​​that would lower the heating value of natural ...

The price of feedstock is one of the most significant factors affecting the economic viability of biodiesel manufacturer. Many approaches were investigated to reduce the biodiesel production cost. The present work gave a preliminary study of two approaches to economically produce biodiesel from waste cooking oil (WCO) and flaked cottonseed. One was the use of ultrasound-assisted synthesis of bi...