D. Stolten – Hydrogen Science and Engineering (2016)

Описание

A critical issue facing the world’s refiners today is the changing landscape in
processing petroleum crude into refined transportation fuels under an environment
of increasingly more stringent clean fuel regulations, decreasing heavy fuel
oil demand, and increasing supply of heavy, sour crude. Hydrogen network optimization
is at the forefront of world refineries options to address clean fuel
trends, to meet growing transportation fuel demands and to continue to make a
profit from their crudes [1]. A key element of a hydrogen network analysis in a
refinery involves the capture of hydrogen in its fuel streams and extending its
flexibility and processing options. Thus, innovative hydrogen network optimization
will be a critical factor influencing future refinery operating flexibility and
profitability in a shifting world of crude feedstock supplies and ultra-low-sulfur
(ULS) gasoline and diesel fuel.
The chemical nature of the crude oil used as the refinery feedstock has always
played the major role in determining the hydrogen requirements of that refinery.
For example, the lighter, more paraffinic crude oils will require somewhat less
hydrogen for upgrading to, say, a gasoline product than a heavier more asphaltic
crude oil. It follows that the hydrodesulfurization of heavy oils and residua
(which, by definition, is a hydrogen-dependent process) needs substantial
amounts of hydrogen as part of the processing requirements.
In fact, the refining industry has been the subject of the four major forces that
affect most industries and which have hastened the development of new petroleum
refining processes: (i) the demand for products such as gasoline, diesel, fuel
oil, and jet fuel, (ii) feedstock supply, specifically the changing quality of crude oil
and geopolitics between different countries and the emergence of alternate feed
supplies such as bitumen from tar sand (oil sand), natural gas, and coal, (iii) technology
development such as new catalysts and processes, especially processes
involving the use of hydrogen, and (iv) environmental regulations that include
more stringent regulations in relation to sulfur in gasoline and diesel [2–6]. Categories (i), (ii), and (iv) are directly affected by the third category (i.e., the
use of hydrogen in refineries) and it is this category that will be the subject of
this chapter. This chapter presents an introduction to the use and need for
hydrogen petroleum refineries in order for the reader to place the use of hydrogen
in the correct context of the refinery. In fact, hydrogen is key in allowing
refineries to comply with the latest product specifications and environmental
requirements for fuel production being mandated by market and governments
and helping to reduce the carbon footprint of refinery operations.
The history and evolution petroleum refining has been well described elsewhere
[6,7] and there is little need to repeat that work here except to note that
it is not the intent of this chapter to ignore the myriad of processes in modern
refineries that do not use hydrogen but may be dependent upon hydrogenated
products in one way or another.