Data Pabrik Semen di Indonesia

Pada saat tulisan ini dibuat, informasi mengenai jumlah pabrik semen yang telah beroperasi secara komersil di Indonesia adalah delapan (8) perusahaan. Dan menurut data di kompas.com (17/2/2010), disebutkan bahwa tidak ada pembangunan pabrik semen baru di Indonesia sejak 10 tahun yang lalu.

Bulan April 2010 ini, diperkirakan pabrik semen baru milik PT. Gunung Pantara Barisan di Sumut akan segera beroperasi. Anda bisa membaca infonya secara lengkap di sini.Di bawah ini adalah pabrik semen yang telah beroperasi di Indonesia. Informasinya dilengkapi pula dengan tahun pendirian, lokasi pabrik, jumlah unit (pabrik), kapasitas produksi dan alamat situs masing-masing pabrik semen.

PT.Indocement Tunggal Prakarsa (Semen Tigaroda)
Lokasi: Citeureup (Bogor), Palimanan (Cirebon), Tarjun (Kalsel)
Didirikan tanggal: 1985
Jumlah pabrik: 12
Kapasitas produksi total: 17.100.000 ton
Website: http://www.indocement.co.id

How Oil Refining Works

Chemical Processing

You can change one fraction into another by one of three methods:

• breaking large hydrocarbons into smaller pieces (cracking)
• combining smaller pieces to make larger ones (unification)
• rearranging various pieces to make desired hydrocarbons (alteration)

Cracking breaks large chains into smaller chains.

Cracking 
Cracking takes large hydrocarbons and breaks them into smaller ones.

There are several types of cracking:

• Thermal - you heat large hydrocarbons at high temperatures (sometimes high pressures as well) until they break apart.
  • steam - high temperature steam (1500 degrees Fahrenheit / 816 degrees Celsius) is used to break ethane, butane and naptha into ethylene and benzene, which are used to manufacture chemicals.
  • visbreaking - residual from the distillation tower is heated (900 degrees Fahrenheit / 482 degrees Celsius), cooled with gas oil and rapidly burned (flashed) in a distillation tower. This process reduces the viscosity of heavy weight oils and produces tar.
  • coking - residual from the distillation tower is heated to temperatures above 900 degrees Fahrenheit / 482 degrees Celsius until it cracks into heavy oil, gasoline and naphtha. When the process is done, a heavy, almost pure carbon residue is left (coke); the coke is cleaned from the cokers and sold.

Oil Refinery

An oil refinery or petroleum refinery is an industrial process plant where crude oilis processed and refined into more useful petroleum products, such as gasoline,diesel fuel, asphalt base, heating oil, kerosene, and liquefied petroleum gas. Oil refineries are typically large sprawling industrial complexes with extensive pipingrunning throughout, carrying streams of fluids between large chemical processingunits. In many ways, oil refineries use much of the technology of, and can be thought of as types of chemical plants. The crude oil feedstock has typically been processed by an oil production plant. There is usually an oil depot (tank farm) at or near an oil refinery for storage of bulk liquid products.

An oil refinery is considered an essential part of the downstream side of thepetroleum industry.

Shell and tube heat exchanger design

Theory and Application

Two fluids, of different starting temperatures, flow through the heat exchanger. One flows through the tubes (the tube side) and the other flows outside the tubes but inside the shell (the shell side). Heat is transferred from one fluid to the other through the tube walls, either from tube side to shell side or vice versa. The fluids can be either liquids or gases on either the shell or the tube side. In order to transfer heat efficiently, a large heat transfer area should be used, leading to the use of many tubes. In this way, waste heat can be put to use. This is an efficient way to conserve energy.

Heat exchangers with only one phase (liquid or gas) on each side can be called one-phase or single-phase heat exchangers. Two-phase heat exchangers can be used to heat a liquid to boil it into a gas (vapor), sometimes called boilers, or cool a vapor to condense it into a liquid (called condensers), with the phase change usually occurring on the shell side. Boilers in steam engine locomotives are typically large, usually cylindrically-shaped shell-and-tube heat exchangers. In large power plants with steam-driven turbines, shell-and-tube surface condensers are used to condense the exhaust steam exiting the turbine into condensate water which is recycled back to be turned into steam in the steam generator.
There can be many variations on the shell and tube design. Typically, the ends of each tube are connected to plenums (sometimes called water boxes) through holes in tubesheets. The tubes may be straight or bent in the shape of a U, called U-tubes.


In nuclear power plants called pressurized water reactors, large heat exchangers called steam generators are two-phase, shell-and-tube heat exchangers which typically have U-tubes. They are used to boil water recycled from a surface condenser into steam to drive a turbine to produce power. Most shell-and-tube heat exchangers are either 1, 2, or 4 pass designs on the tube side. This refers to the number of times the fluid in the tubes passes through the fluid in the shell. In a single pass heat exchanger, the fluid goes in one end of each tube and out the other.