Chemical Engineering May 2016 - 20

water treatment, interconnecting piping,
reliability risk to refinery process
units, and risk to the refinery wastewater-treatment
plant, " he said.
One approach that refineries have
New Products For testiNg crude-oil lauNched
used to produce reuse-quality water
from refinery wastewater is membrane
bioreactor (MBR) technology.
A presentation from gE Water &
Process Technologies (Trevose, Pa.;
www.ge.com) discussed progress
in using MBRs with the company's
MACarrier (membrane-accommodating
carrier) technology, which is a
specialized carbon-based biological
carrier that promotes nitrification, and
enhances the removal of recalcitrant
chemical oxygen demand (COD) and
other toxic compounds.
MACarrier provides a large, bacteria-friendly
surface area where dense
and strong biofilm is quickly formed,
gE explains. It adsorbs and concentrates
the problematic recalcitrant organic
compounds where the biomass
degrades the adsorbed compounds
and regenerates the MACarrier.
gE conducted a pilot study at a
southern Ontario refinery aimed at
comparing the company's existing
MBR system to an MBR system with
MACarrier. Wastewater downstream
of oil-water separator and dissolved
air filtration units was treated by an
MBR and an MBR with MACarrier.
The study found that MBR with
MACarrier " could achieve higher effluent
quality in terms of acute toxicity
and the effluent could be directly
discharged, " while the MBR [without
MACarrier], even though providing
higher effluent quality . . . " could not
meet the toxicity requirements for
discharge, " says gE.
Selenium removal
Another petroleum refinery wastewater-treatment
challenge comes from
the selenium present in some crude
oils. The element, in its several forms
(selenite, selenate, selenocyanate),
must be removed from refinery wastewater
because while selenium is an
essential trace nutrient, it can be toxic
at high concentrations. Regulations on
selenium-release limits have become
more stringent in recent years.
Physical and chemical methods to
remove selenium from refinery wastewater
are difficult, so biological treat20
In
a product launch timed to correspond with the AFPM annual meeting, gE Water & Process
(Trevose, Pa.; www.ge.com) introduced new predictive-analytics software and laboratory
equipment for the on-site testing of crude oil to determine how the oil might affect a petroleum
refinery before processing begins.
gE's CrudePlUS reduces analysis time of crude oil and can lead to streamlined operations,
less fouling and increased energy efficiency, the company says. gE's new digital solution uses
predictive analytics to improve operation and reduce carbon dioxide emissions and costs.
Data captured with CrudePlUS can lead to improved blending and desalter operations that
result in reduced oil to the refinery's wastewater treatment plant.
" As the variability of crude oil increases and refineries adopt more aggressive blending strategies,
there is tremendous value in rapid data and predictive analytics, " says Amy Ericson, global
leader, chemical and monitoring solutions for water and process technologies at gE Power.
gE also introduced its loSAlT Online and Onsite Amine Speciation software, an upgrade
to its loSAlT simulator software. " Previously, refinery operators could only test on-site for a
small number of amines and had to send samples away to a laboratory. gE's new loSAlT
Online and Onsite Amine Speciation technology now offers refineries a more accurate, comprehensive
and instantaneous method of testing and receiving critical data, " says Ericson.
gE's loSAlT Online and Onsite Amine Speciation technology can increase protection of
the crude overhead system by providing a more complete picture of the salting and corrosion
potential than previously possible, says the company.
ment has been explored as a means
of achieving the low selenium levels.
Biological treatment has the potential
to convert various forms of selenium to
elemental selenium, which is relatively
non-toxic, and can be separated from
the wastewater streams as an inert
solid associated with the biomass that
is present in the solids recovered from
the treatment process.
In a paper presented by lori Donovan,
an account manager with UOP
Industrial Wastewater Technologies
(Des Plaines, Ill.; www.uop.com), a
pilot study was discussed in which
UOP's (Honeywell) XCeed SE Bioreactor
was used to remove selenium
from wastewater at a refinery in the
western U.S.
Using UOP's immobilized-cell biological-treatment
technology, XCeed
consists of a series of bioreactors and
UOP's proprietary biological growth
media, and was set up as an onsite
field trial. The system was inoculated
using nitrate-reducing cultures that
were developed during a previous
laboratory study. Organic carbon and
phosphoric acid were dosed to provide
nutrients for biological growth.
In order to discharge to a local municipal
treatment plant, the refinery
needed to reduce the selenium present
in its final water discharge from
a level of approximately 200 μg/l
to less than 50 μg/l. Donovan said
the pilot testing successfully demonstrated
that the XCeed SE biotreatment
technology " can meet the total
recoverable selenium target of 50
μg/l without the need for post-treatment,
allowing the refinery to comply
with local regulations. "
n
Scott Jenkins
ChemiCal engineering www.Chemengonline.Com may 2016

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Chemical Engineering May 2016

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