Chemical Engineering

Chemical engineering is the discipline in which knowledge of mathematics, physics, chemistry and biology, gained by study, experience and practice, is applied with judgement to develop economic and safe ways of converting raw materials into more useful products to benefit mankind. It is devoted to the chemical, physical or biological transformation of matter or energy into useful forms, economically and safely without compromising the natural environment.

  • Halocarbon Featured Article Halocarbon Halocarbon

    A halocarbon is an organic chemical molecule composed of at least one carbon atom bound covalently with one or more halogen atoms; the most common halogens in these molecules... More »

  • Large-scale trickle filters Featured Article Large-scale trickle filters Large-scale trickle filters

    Large-scale trickle filters are wastewater treatment facilities for biochemically oxidizing biodegradable substances present in municipal or industrial wastewater. They consist... More »

  • Flue gas desulfurization Featured Article Flue gas desulfurization Flue gas desulfurization

    Flue gas desulfurization is commonly known as FGD and is the technology used for removing sulfur dioxide (SO2) from the exhaust combustion flue gases of power plants that... More »

  • Chemical reaction Featured Article Chemical reaction Chemical reaction

    A chemical reaction is a process that transforms one set of chemical substances to another. The substances that take part in chemical reactions are known as reactants and the... More »

  • Fluid catalytic cracking Featured Article Fluid catalytic cracking Fluid catalytic cracking

    Fluid catalytic cracking (FCC) is the most important conversion process used in petroleum refineries. It is widely used to convert the high-boiling hydrocarbon fractions of... More »

  • Petrochemicals Featured Article Petrochemicals Petrochemicals

    Petrochemicals are chemical products made from the hydrocarbons present in raw natural gas and petroleum crude oil. The largest petrochemical manufacturing industries are to... More »

  • Petroleum refining processes Featured Article Petroleum refining processes Petroleum refining processes

    Petroleum refining processes are those chemical engineering processes and other facilities used in petroleum refineries (also referred to as oil refineries) to transform... More »

Recently Updated
Counter current exchange Last Updated on 2014-06-19 15:47:30 Counter current exchange is the mechanism by which some property of a fluid, such as heat or a chemical substance, is transferred from one fluid across a semi-permeable membrane or thermally conductive material to another fluid flowing in the opposite direction. The general requirements for counter current exchange are (1) that two fluids flow in close proximity to each other and (2) that the fluids flow in opposite directions. The purpose of counter current exchange is to maintain a concentration gradient between the two fluids in order to maximize movement from one fluid to the other. The opposite of counter current exchange occurs in concurrent exchange when two fluids flow in the same direction. The principle of counter current exchange can be illustrated using fish gills. In the gills, oxygen diffuses from an area of high concentration, the water, into an area of lower... More »
Concentration expressions and notations Last Updated on 2014-06-18 18:21:06 In chemistry and other sciences, engineering and in fairly common usage, concentration is the measure of how much of a given substance there is in a given mixture of substances. There are many different notations and quantitative expressions of concentration.[1] The most commonly used expressions are discussed below: The mole fraction is a measure of the concentration of a component substance in a mixture of substances. It is defined as the number of moles of a component substance in a mixture divided by the total number of moles of the mixture.[2][3] The mole percent  (also referred to as the molar percent) is usually denoted by mole % and is equal to 100 times the mole fraction. The mass fraction is also a measure of the concentration of a component substance in a mixture of substances. It is defined as the mass of a component substance in a mixture divided by the total... More »
Plastic products and estrogenic chemicals Last Updated on 2014-06-14 12:26:55 Chemicals that mimic or antagonize the actions of naturally occurring estrogens are defined as having estrogenic activity (EA), which is the most common form of endocrine disruptor activity. This article, written by Chun Z. Yang, Stuart I. Yaniger, V. Craig Jordan, Daniel J. Klein, and George D. Bittner* appeared first in Environmental Health Perspectives—the peer-reviewed, open access journal of the National Institute of Environmental Health Sciences. The article is a verbatim version of the original and is not available for edits or additions by Encyclopedia of Earth editors or authors. Companion articles on the same topic that are editable may exist within the Encyclopedia of Earth. Most Plastic Products Release Estrogenic Chemicals: A Potential Health Problem That Can Be Solved Background: Chemicals having estrogenic activity (EA) reportedly cause many adverse health... More »
Biochar: Concept to Sequester Carbon Last Updated on 2014-06-11 15:45:52 Biochar is a charcoal produced under high temperatures using crop residues, animal manure, or any type of organic waste material. Depending on the feedstock, biochar may look similar to potting soil or to a charred substance. The combined production and use of biochar is considered a carbon-negative process, meaning that it removes carbon from the atmosphere. Biochar has multiple potential environmental benefits, foremost the potential to sequester carbon in the soil for hundreds to thousands of years at an estimate. Studies suggest that crop yields can increase as a result of applying biochar as a soil amendment. Some contend that biochar has value as an immediate climate change mitigation strategy. Scientific experiments suggest that greenhouse gas emissions are reduced significantly with biochar application to crop fields. Obstacles that may stall rapid adoption of biochar... More »
Hydrodesulfurization Last Updated on 2013-12-15 23:43:02 Hydrodesulfurization (HDS) or Hydrotreating is a catalytic chemical process widely used to remove sulfur compounds from refined petroleum products such as gasoline or petrol, jet fuel, diesel fuel, and fuel oils. One purpose for removing the sulfur is to reduce the sulfur dioxide emissions resulting from using those fuels in automotive vehicles, aircraft, railroad locomotives, ships, or oil burning power plants, residential and industrial furnaces, and other forms of fuel combustion. Another important reason for removing sulfur from the intermediate product naphtha streams within a petroleum refinery is that sulfur, even in extremely low concentrations, poisons the noble metal catalysts platinum and rhenium in the catalytic reforming units that are subsequently used to upgrade the of the naphtha streams. Hydrogenation of the sulfur compounds results in the formation of undesirable,... More »