Chemical Engineering May 2016 - 18

8000
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X5
X3
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Figure 1. Radial plots depict multi-variable data samples using axes extending outward from a central
point, while the time dimension is represented by stacking the data samples
octane number of resulting gasoline.
Alkylate, a high-octane, low-sulfur
blendstock, offers a way to raise octane
numbers. Meanwhile, another
factor is the availability of inexpensive
butanes from shale deposits in the
U.S., making for a potentially cheap
feedstock for alkylation.
Solid-acid catalysts
The past several months have seen
the culmination of years of development
for solid-acid catalysts for alkylation
that can replace liquid-acid
catalyst systems using the hazardous
and corrosive hydrofluoric and sulfuric
acids as catalysts.
At the AFPM meeting, CB&I (The
Woodlands, Tex.; www.cbi.com) discussed
the progress of what is said to
be the world's first commercial-scale,
solid-acid-catalyst alkylation unit.
The unit started up in August 2015
at Zibo Haiyi Fine Chemical Co., a
subsidiary of Shandong Wonfull Petrochemical
group Co. The unit employs
CB&I's AlkyClean technology,
jointly developed by CB&I, Albemarle
Corp. (Baton Rouge, la.; www.albemarle.com)
and Neste Corp. (Espoo,
Finland; www.neste.com). The unit
has a capacity of 2,700 barrels per
day of alkylate production (100,000
metric tons per year).
The unit, located in Shandong
Province, China, has achieved all
18
performance expectations thus far,
CB&I says. Since the startup, the
alkylate product has demonstrated
excellent quality, the company
points out, including an octane
value (RON) between 96 and 98
- a considerably higher RON than
typical alkylate products, according
to CB&I. RON is considered an indicator
of the alkylate's value as a
gasoline blending component.
AlkyClean technology uses Albemarle's
AlkyStar catalyst, a robust
fixed-bed zeolite catalyst. By pairing
this catalyst with CB&I's novel reactor
scheme, the AlkyClean process
is able to produce a high-quality
alkylate product without the use of
liquid-acid catalysts, which makes
the process inherently safer. By eliminating
the need for post-treatment,
and waste streams of acid-soluble
oils, the process offers an efficient
alkylate-production technology. For
more information on the CB&I solidacid
catalyst alkylation process, see
Chem. Eng., April 2013, p. 11.
In February 2016, kBR Inc. (Houston,
Tex.; www.kbr.com) announced
the first licensing contract for its kSAAT
Solid Acid Alkylation technology.
The contract was awarded to kBR by
Dong Ying Haike Ruilin Chemical Co.
for use at a facility in Dong Ying City,
China. kBR is supplying the technology
know-how, basic process design,
key equipment and catalyst. The Haike
k-SAAT unit is anticipated to start up
in q1 2017, kBR says.
The k-SAAT process features a
solid-acid catalyst, known as ExSact,
which is based on modifications
of commercially available zeolite catalysts,
and is much less hazardous to
both personnel and the environment
than liquid-acid catalysts. These aspects
and the lower installed cost for
the k-SAAT process influenced Haike's
decision to select the k-SAAT
process over conventional sulfuric
acid alkylation technologies. kBR's
gautham krishnaiah, director, FCC &
Alkylation Technologies, says the operating
expenses for solid-acid catalyst
systems for alkylation are also
lowered because k-SAAT has lower
maintenance costs and does not require
refrigeration (unlike the sulfuricacid-catalyzed
alkylation process). In
addition, liquid-acid regeneration and
disposal of solid wastes (acid neutralization
with caustic) are not required.
kBR has partnered with Exelus,
Inc. (livingston, N.J.; www.exelusinc.
com), a developer of green chemical
technologies, and now has an exclusive
license for Exelus' ExSact catalyst.
The k-SAAT process employs
two reactors - one in the alkylation
cycle and one in the regeneration
cycle or on standby. The process
uses hydrogen to completely regenerate
the catalyst. During this regeneration,
the soft coke (a combination
of highly unsaturated hydrocarbons)
and contaminants adsorbed on the
catalyst are released and purged,
kBR's krishnaiah says.
The ExSact catalyst has been engineered
to outperform liquid-acid catalysts
and other solid-acid catalysts on
multiple levels, says kBR's krishnaiah.
The catalyst acid sites and pore
structure have been optimized to enhance
product selectivity. The ExSact
catalyst offers long alkylation cycles
in comparison with other solid-acidalkylation
catalysts; a high degree of
flexibility in terms of the feed sources
and components (ethylene, propylene,
butylenes and amylenes can be
used as the olefins). In contrast, liquidacid
alkylation processes cannot alkylate
ethylene, he says, since ethylene
forms stable esters. In addition kBR's
solid-acid process has a higher tolerChemiCal
engineering www.Chemengonline.Com may 2016
Time (mins)

http://www.exelusinc http://www.cbi.com http://www.albe http://www.kbr.com http://www.marle.com http://www.neste.com http://www.Chemengonline.Com

Chemical Engineering May 2016

Table of Contents for the Digital Edition of Chemical Engineering May 2016