Light Crude
Light Crude is a term used to define crude oils with a higher fraction of lower boiling point components and low wax content. Some definitions have Light Crude defined as a crude with an specific gravity index greater than 28 API, although more commonly this range would include Medium and Light crudes.
Linear Alkyl Benzene (LAB)
Linear alkyl benzene (LAB) is the dominant detergent intermediate. It is mainly produced by the dehydrogenation of n-paraffins to internal olefins followed by alkylation with benzene using hydrofluoric acid catalyst. Almost all LAB is converted to linear alkyl sulfonates, a major surfactant in household cleaning products.
Linear Alpha Olefins (LAO)
Linear alpha olefins (LAO) are produced by two families of processes
- full-range and on-purpose. LAOs are produced by the oligomerization of ethylene in full-range processes. On-purpose technologies are used to produce butene-1 (extractive distillation, hydrogenation/fractionation and ethylene dimerization), hexene-1 (fischer-tropsch and ethylene trimerization) and octene-1 (fischer-tropsch). Alpha olefins cover a wide range of products used in diverse applications. The lighter components (butene-1, hexene-1 and octene-1) are used as comonomers in polyethylene production. Decene-1 is principally used to manufacture polyalpha olefins for the production of high performance lubricants. Higher alpha olefins in the C12/C14 range are consumed in the production of detergent alcohols, while those in the C16/C18 range are predominately used in the oilfield chemicals sector and paper industry, and the higher fractions (C20+) are used to manufacture lubricant additives and specialty waxes.
Linear Low Density Polyethylene (LLDPE)
Linear low density polyethylene (LDPE) is a relatively new polyethylene that shares many of the performance characteristics of LDPE. LLDPE is most commonly used in film applications. It is produced by the low pressure catalysed reaction of ethylene with small quantities of higher alpha-olefin (most commonly butene-1). This low pressure technology provides LLDPE with a cost advantage over LDPE, although this advantage is partly surrendered as it is a more difficult polymer to process than LDPE.
Low Density Poly-ethylene (LDPE) - Autoclave
There are two basic processes used for the manufacture of LDPE, autoclave and tubular. ICI developed the first LDPE technology as a stirred autoclave process in the late 1930s. The autoclave process is adiabatic, in that there is no significant heat removal from the reactor during the process. The modern stirred autoclave reactor may have a volume of 3 000 litres and four to six zones, each running at a different temperature, thus enabling direct control of the mix of molecular species and degree of long chain branching. The high-pressure polymerisation of ethylene is a free radical promoted reaction and the autoclave operators almost always use organic peroxides as initiators.
Low Density Poly-ethylene (LDPE) - Tubular
There are two basic processes used for the manufacture of LDPE, autoclave and tubular. The tubular reactor process was originally developed by BASF. In the tubular design, the reactants are cooled along the long jacketed tube reactor. Tubular reactors can have several zones where fresh ethylene and initiator are added. The addition of fresh ethylene both cools the reactants and agitates the mixture so that the molecular weight distribution can be varied.
Low Density Polyethylene (LDPE)
Low density polyethylene (LDPE) was the first polyethylene to be produced and is a member of the polyolefin family. LDPE is used in a wide range of applications, the most common being consumer plastic bags. LDPE goods are commonly marked with a 4 following the recycling codes developed by the American Society of the Plastics Industry. LDPE demand is under pressure from more modern and lower cost polymers including its fellow polyethylene LLDPE. LDPE is formed by the high pressure catalysed reaction of ethylene monomers in either tubular or autoclave reactors.