出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2013/10/15 16:17:21」(JST)
A refinery is a production facility composed of a group of chemical engineering unit processes and unit operations refining certain materials or converting raw material into products of value.
Different types of refineries are as follows:
The image below is a schematic flow diagram of a typical oil refinery depicting various unit processes and the flow of intermediate products between the inlet crude oil feedstock and the final products. The diagram depicts only one of the hundreds of different configurations. It does not include any of the usual facilities providing utilities such as steam, cooling water, and electric power as well as storage tanks for crude oil feedstock and for intermediate products and end products.[1][2]
The image below is a schematic block flow diagram of a typical natural gas processing plant. It shows various unit processes converting raw natural gas into gas pipelined to end users.
The block flow diagram also shows how processing of the raw natural gas yields byproduct sulfur, byproduct ethane, and natural gas liquids (NGL) propane, butanes and natural gasoline (denoted as pentanes +).[3][4][5][6][7]
Sugar is generally produced from sugarcane or sugar beets. However, the global production of sugar from sugarcane is at least twice the production from sugar beets. Therefore, this section focuses on sugar from sugarcane.
Sugarcane is traditionally refined into sugar in two stages. In the first stage, raw sugar is produced by the milling of freshly harvested sugarcane. In a sugar mill, sugarcane is washed, chopped, and shredded by revolving knives. The shredded cane is mixed with water and crushed. The juices (containing 10-15 percent sucrose) are collected and mixed with lime to adjust pH to 7, prevent decay into glucose and fructose, and precipitate impurities. The lime and other suspended solids are settled out, and the clarified juice is concentrated in a multiple-effect evaporator to make a syrup with about 60 weight percent sucrose. The syrup is further concentrated under vacuum until it becomes supersaturated, and then seeded with crystalline sugar. Upon cooling, sugar crystallizes out of the syrup. Centrifuging then separates the sugar from the remaining liquid (molasses). Raw sugar has a yellow to brown color. To produce a white sugar, sulfur dioxide is bubbled through the cane juice before evaporation so as to bleach color-forming impurities into colourless ones. Sugar bleached white by this means is called mill white, plantation white, and crystal sugar. It is the form of sugar most often consumed in the sugarcane-producing countries.
The fibrous solids, called bagasse, remaining after the crushing of the shredded sugarcane, are burned for fuel, which helps a sugar mill to become self-sufficient in energy. Any excess bagasse can be used for animal feed, to produce paper, or burned to generate electricity for the local power grid.
The second stage is often executed in heavy sugar-consuming regions such as North America, Europe, and Japan. In the second stage, white sugar is produced that is more than 99 percent pure sucrose. In such refineries, raw sugar is further purified.
The pyrolysis method for refining used tires is a technique which heats whole or shredded tires in a reactor vessel containing an oxygen free atmosphere and a heat source. In the reactor the rubber is softened after which the rubber polymers continuously break down into smaller molecules. These smaller molecules eventually vaporize and exit from the reactor. These vapors can be burned directly to produce power or condensed into an oily type liquid, generally used as a fuel. Some molecules are too small to condense. They remain as a gas which can be burned as fuel. The minerals that were part of the tire, about 40% by weight, are removed as a solid. When performed well a tire pyrolysis process is a very clean operation and has nearly no emissions or waste.[8]
Anhydrous pyrolysis can also be used to produce liquid fuel similar to diesel from plastic waste. Pilot Jeremy Roswell plans to make the first flight from Sydney to London using diesel fuel from recycled plastic waste.
In many industrial applications, the process is done under pressure and at operating temperatures above 430 °C (806 °F). For agricultural waste, for example, typical temperatures are 450 to 550 °C (840 to 1,000 °F).
Pyrolysis is the decomposition of organic compounds under oxygen free (anaerobic) atmosphere that produces gas, oil, carbon black and steel. Efficient industrial Pyrolysis is a process to treat the rubber and industrial plastic wastage as well.
As a result of pyrolysis of waste plastic one obtains,[10]
FUEL OIL (55% to 65%) The main oil product produced by our recycling application is the fuel oil that is wide used for industrial and commercial purposes. The oil has 40% to 45% of the amount of recycled scrap tyres, which will be carried with licensed tanker trucks.
CARBON BLACK (30% t0 35%) Carbon Black is the main product recycled by Pyrolysis technology. The amount of recycled carbon black is 30% to 35% (depending on the type of tyres) of the total amount of scrap tyres recycled in the system. Carbon black is used as raw material or main ingredient in many industries and the chemical structure of carbon black strengthens, lengthens the endurance, and improves the coloring features of the materials.
GAS (10% to 12%) Non-Condensable gases arise during the pyrolysis process. There aresome advantages such as ...
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