Refinery hydrogen

Clausen, G., Chan, T., Nongbri, G., and Kaufman, H., Texaco Processes for a Bottomless Hydrogen Refinery, paper presented at the Japan Petroleum Institute Conference on Refining Technologies, Tokyo (1992)... 

Fig. 4. Erection of a 675-ton hydrocracking reactor at Shauaiba, Kuwait, refinery, the world s first all-hydrogen refinery. (The Fluor Corp)...

Unifining a fixed-bed catalytic process to desulfurize and hydrogenate refinery distillates. 

Based on existing technology, a refinery hydrogen unit, using crude oil as a feedstock and a rated output of IOOMW-H2, has a capital cost of 50 million, or an overnight capital cost of approximately 500.5 /kW-H2 (CONCAWE 1999). Based on a thermal efficiency of 36.8%, the crude oil input for this facility is estimated at 8.6 million GJ per year, or 3.1 million GJ-H2. The O M costs are difficult to separate from that of the refinery itself. H2 im initially assumes annual O M costs for the hydrogen refinery unit are 4% of the overnight capital costs. 

The product hydrogen would be aimed primarily at supplying the hydrocracker. Sufficient flexibility can, however, be built into the gas treatment facilities to accommodate alternative scenarios in the overall hydrogen refinery balance and to produce methanol for methyl-tert-butyl ether (MTBE) production or other uses. 

It is clear that these gases have widely varying compositions according to the processes used, but refinery gas is distinguished from natural gases by the presence of hydrogen, mono- and diolefins, and even acetylenes. 

Hydrogen sulfide concentrates in refinery off gases. Before being used as fuel gas, the gas undergoes an amine (MEA, DEA, etc.) washing step in order to extract the H2S. 

Purification of refinery gases by elimination of hydrogen sulfide as well as Claus units for sulfur recovery began to make their appearance. 

We cite isomerization of Cs-Ce paraffinic cuts, aliphatic alkylation making isoparaffinic gasoline from C3-C5 olefins and isobutane, and etherification of C4-C5 olefins with the C1-C2 alcohols. This type of refinery can need more hydrogen than is available from naphtha reforming. Flexibility is greatly improved over the simple conventional refinery. Nonetheless some products are not eliminated, for example, the heavy fuel of marginal quality, and the conversion product qualities may not be adequate, even after severe treatment, to meet certain specifications such as the gasoline octane number, diesel cetane number, and allowable levels of certain components. 

Since 1960, about 95% of the synthetic ammonia made in the United States has been made from natural gas worldwide the proportion is about 85%. Most of the balance is made from naphtha and other petroleum Hquids. Relatively small amounts of ammonia are made from hydrogen recovered from coke oven and refinery gases, from electrolysis of salt solutions, eg, caustic chlorine production, and by electrolysis of water. In addition there are about 20 ammonia plants worldwide that use coal as a hydrogen source. 

Mixtures of CO—H2 produced from hydrocarbons, as shown in the first two of these reactions, ate called synthesis gas. Synthesis gas is a commercial intermediate from which a wide variety of chemicals are produced. A principal, and frequendy the only source of hydrogen used in refineries is a by-product of the catalytic reforming process for making octane-contributing components for gasoline (see Gasoline and OTHER MOTOR fuels), eg. 

This by-product hydrogen can be used as fuel or purified and used in other chemical or refinery operations. 

Refinery hydrogen requirement is met either by direct manufacture or indirect by-product recovery. Manufacture is typically by steam methane... 

Table 4 summarizes commercial and precommercial gas separation appHcations (86,87). The first large-scale commercial appHcation of gas separation was the separation of hydrogen from nitrogen ia ammonia purge gas streams. This process, launched ia 1980 by Monsanto, was followed by a number of similar appHcations, such as hydrogen—methane separation ia refinery off-gases and hydrogen—carbon monoxide adjustment ia oxo-chemical synthetic plants. 

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