Heavy Crude is a term used to define crude oils with a high fraction of high boiling point waxy components such that processing cannot be performed in "normal" refinery operations. Heavy Crude is defined as those crudes having a specific gravity below 28 API and include some Venezuelan oils and oil from Canadian Tar Sand deposits.
Hexamethylene diamine or 1,6-diaminohexane (HMDA)
Hexamethylene diamine or 1,6-diaminohexane (HDMA) is produced by catalytic hydrogenation of adiponitrile. The majority of HMDA is reacted with adipic acid to produce nylon 6,6 in a two-step process.
High Density Polyethylene (HDPE)
High density polyethylene (HDPE) is the name given to the densest member of the polyethylene family. HDPE is more rigid and opaque than the other polyethylenes and is used in many packaging and container applications which benefit from its strength and high temperature resistance. HDPE goods are commonly marked with a 2 following the recycling codes developed by the American Society of the Plastics Industry. HDPE was initially produced by low pressure reaction of ethylene monomers with specialized Ziegler-Natta catalysts in slurry reactors. More recently production has also been obtained by low pressure gas phase HDPE/LLDPE swing plants.
Higher oxo-alcohols are collectively the heavier, smaller volume oxo-alcohols which are produced in addition to the principal oxo-alcohols 2-ethylhexanol and butanols. Oxo-alcohols are so named because of the “oxo process” process by which they are produced, which involves hydroformulation of an olefin with syngas. Higher oxo-alcohols have a wide variety of end-uses ranging from pesticides to perfumery. Higher oxo-alcohol production is relatively specialised and small volume chemistry and tends to be restricted to large industrial economies.
Hydrodealkylation of toluene to benzene is the most common dealkylation route. The use of toluene dealkylation is sensitive to the producer's alternative value for toluene (i.e. gasoline or chemicals), the hydrogen value (on-purpose or by-product), as well as the benzene market price. As a result the motivation to dealkylate is very different for each producer with some producers dedicated to dealkylate at all times (usually lacking a sufficient gasoline pool or chemical market for toluene) while others are "opportunistic" dealkylators, running their plants at times when the economics fully justify and encourage the process and spot benzene sales are available.
Hydrogenation is a chemical reduction reaction which results in the addition of hydrogen to an unsaturated compound (e.g. alkenes). Metal catalysts are typically used for these reactions, including cobalt-molybdenum or nickel-molybdenum