A glossary of common terms and abbreviations used in the industry, with links to more in-depth articles on key words
H2S - (hydrogen sulfide) gas generated from the processing of crude oil containing sulfur
HAGO - (Heavy atmospheric gasoil) a distillation cut derived from an atmospheric distillation unit primarily comprised of molecules with 14 to 20 carbon atoms
Handil (crude) - a medium, sweet crude grade produced in Indonesia
Hardisty - a major crude oil blending, storage, trading and transportation hub in western Canada
HCK - (Hydrocracker) a refinery process unit that upgrades heavy fractions (such as VGO) through thermal catalytic cracking while injecting hydrogen
HDA - (Hydrodealkylation) a process that removes an alkyl group, in particular converting toluene into benzene
HDO - (Hydrodeoxygenation) a refinery process unit that removes oxygen from a feedstock or intermediate streams before being fed into another refinery process unit
HDN - (Hydrodenitrogenation) a refinery process unit that removes nitrogen from intermediate streams before being fed into another refinery process unit
HDS - (Hydrodesulfurization) a refinery process unit that removes sulfur from intermediate streams before blending into finished product or before being fed into another refinery process unit
Heating oil - a diesel range light product used for non-transportation purposes
Heating value - a measure of the useful heat (or energy) that comes from burning a fuel
Hebron (crude) - a heavy, sweet crude grade produced in Eastern Canada
HEFA (product) - (Hydroprocessed esters and fatty acids) renewable diesel produced from a HEFA unit
HEFA (unit) - (Hydroprocessing esters and fatty acids) a renewable fuels plant that hydroprocesses vegetable oils or animal fats
Heavy atmospheric gasoil - a distillation cut derived from an atmospheric distillation unit primarily comprised of molecules with 14 to 20 carbon atoms
Heavy fuel oil - one of the lowest-value petroleum products from a refinery
Heavy hydrocrackate - a heavy naphtha range product from a hydrocracker. It is typically used as a reformer feed
Heavy naphtha - a distillation cut comprised material of roughly the same density as finished gasoline
Hedging - the use of commercial contracts to reduce market risk exposure
HF - (Hydrofluoric acid) one of the two acids used as a catalyst in the alkylation process, the other being sulfuric acid
HF alkylation - one of the two most common alkylation processes, the other being sulfuric acid alkylation
HHV - (Higher heating value) measure of the amount of heat generated from full combustion of a hydrocarbon and a return of all combustion products (including steam) to pre-combustion temperature
Hibernia (crude) - a light, sweet crude grade produced in Eastern Canada
High sulfur fuel oil - (HSFO) one of the lowest-value petroleum products from a refinery
Higher heating value - (HHV) measure of the amount of heat generated from full combustion of a hydrocarbon and a return of all combustion products (including steam) to pre-combustion temperature
HLS (crude) - a medium, sweet crude grade produced in the US
H-Oil unit - a type of resid hydrocracker, a refinery unit that upgrades vacuum resid through cracking while injecting hydrogen
Houdry - a type of FCC, the most common conversion unit used in refining to upgrade heavier distillation cuts to light products
Houston ship channel - the waterway running through the Port of Houston, Texas in the US
HSE - (Health, safety and environmental) a refinery's performance in protecting worker health and safety, and the impact of the refinery operations on the environment
HSFO - (High sulfur fuel oil) one of the lowest-value petroleum products from a refinery
HTU - (hydrotreating unit) a refinery process unit that removes sulfur from intermediate streams before blending into finished product or before being fed into another refinery process unit
Hub market - the large regional refining centers that tend to act as swing capacity for global market and the location for most spot trade in refined products
Hungo (crude) - a medium, sweet crude grade produced in Angola
HVO - (Hydrotreated vegetable oil) renewable diesel or SAF made from hydroprocessing vegetable oils
HYCON - a type of resid hydrocracker, a refinery unit that upgrades vacuum resid through cracking while injecting hydrogen
Hydrocarbon - any substances comprised of carbon and hydrogen. This includes crude oil and all petroleum products, as well as natural gas and coal
Hydrocracker - (HCK) a refinery process unit that upgrades heavy fractions (such as VGO) through thermal catalytic cracking while injecting hydrogen
Hydrocracker distillate - one of the key products from the hydrocracker. It is a high quality diesel blendstock, with low sulfur and high cetane
Hydrocracker gasoil - a low-sulfur VGO range material produced by the hydrocracker. Its primary use is as a feed into the FCC unit
Hydrocracker kerosene - a low-sulfur kerosene range material produced by the hydrocracker
Hydrodealkylation - (HDA) a process that removes an alkyl group, in particular converting toluene into benzene
Hydrodenitrogenation - (HDN) a refinery process unit that removes nitrogen from intermediate streams before being fed into another refinery process unit
Hydrodeoxygenation - (HDO) a refinery process unit that removes oxygen from a feedstock or intermediate streams before being fed into another refinery process unit
Hydrodesulfurization unit - (HDU) a refinery process unit that removes sulfur from intermediate streams before blending into finished product or before being fed into another refinery process unit
Hydrofluoric acid - (HF) one of the two most common alkylation processes, the other being sulfuric acid alkylation
Hydrogen - (H2) an important feed stock to many process units, which use it to remove impurities (e.g., hydrotreaters) and to saturate cracked components (e.g., hydrocrackers)
Hydrogen plant - a group of refinery process units that supplies hydrogen for all the needs of the hydrotreaters and hydrocrackers
Hydrogen sulfide gas - (H2S) a gas generated from the processing of crude oil containing sulfur
Hydrogenation - any process or reaction in which hydrogen is added to an unsaturated hydrocarbon molecule
Hydroprocessing - a category of catalytic process units that adds hydrogen. Includes hydrotreating and hydrocracking
Hydroprocessing esters and fatty acids - (HEFA)a renewable fuels plant that hydroprocesses vegetable oils or animal fats
Hydroskimmer - the primary means of upgrading low-octane heavy naphtha to make gasoline that meets minimum octane requirements
Hydroskimming - (HSK) a refining configuration that consists only of atmospheric distillation, reforming and hydrotreating
Hydrotreated vegetable oil - (HVO) renewable diesel or SAF made from hydroprocessing vegetable oils
Hydrotreater - (HTU) a refinery process unit that removes sulfur from intermediate streams before blending into finished product or before being fed into another refinery process unit