Drexel University Environmental Impacts Report The simulated situation is a request to prepare a thorough written report that will be used to be included a

Drexel University Environmental Impacts Report The simulated situation is a request to prepare a thorough written report that will be used to be included as a permanent part of company files on this project. It should be written as if it will cover technical aspects of the overall project, but also by upper management to help guide them in deciding whether the company should proceed with the project. Take this into account when preparing the report. Don’t assume that they already know as much about the environmental issues as you do.

I am leaving it up to you to organize your report. Here are a few hints:

make sure it starts with an introduction

break it up into subsections relating to the various types of environmental impacts
use different levels of subheadings within each major section
finish with a conclusion/recommendation regarding whether to proceed, based upon potential environmental issues

I have asked the process engineering team to assess potential environmental issues that might be associated with the process we are developing. Many of these potential issues are associated with specific individual unit processes, and others are associated with the plant in general. Please summarize the environmental issues that you have identified, which must be addressed in the design. Since we must minimize our overall environmental impacts, please describe the mitigation measures that you feel will be appropriate for each type of potential impact, and why you selected that measure. If you believe it will be necessary to obtain operating permits from regulatory agencies, be sure to address this in your report.

Since there may be many different issues, please give me a detailed analysis of the potential impacts that you consider to be most critical. This should include a description of the type of environmental impact (emissions, etc.) associated with various aspects of the plant. Let me know if you have identified which mitigation measures you believe are required to reduce each potential environmental impact to an acceptably low level. Since I will have to pass your response to higher levels of management who do not have your technical expertise, please try to explain the mitigation method itself and why you think it will be effective.

In addition to the major environmental issues you have identified, please also include (probably in a well-organized table) a listing of the other lesser potential impacts you have identified. Please include a very abbreviated version of the same topics (emissions, the relative importance of potential impacts, and a short description of the best mitigations you have identified).

If you have identified a potential environment impact for which you cannot propose an acceptable mitigation, this might be a “show-stopper” for the project. So be sure to thoroughly analyze anything of that sort and make an appropriate recommendation. If you believe you can mitigate against all of the potential environmental impacts you have considered, make appropriate recommendations. If your mitigation method requires any new equipment, processes or operational protocols that were not part of the original process design, please make sure to report them.

Since your recommendations will play a large part in how we demonstrate our goal to protect the environment, please be thorough in your analysis.

NOTE: attached the safety report. and also the whole design report you may need it.

it should be minimum 12 pages. For assurance of a high degree of safety within the plants of manufacturing chemicals,
certain guidelines need to be established as the standard in order to promote a comfortable and
safe working environment. The precautions need to be tailored to specific kinds of factories so
as to cater to the myriad of issues that can arise within such a setup.
Concerns With The Plant
The process that will be of central focus will be the production of isopentane from npentane. For the plant will be tweaked to accommodate the expectations of the production, then
safety will also have to be accounted for. Costs may not be colossal for there is a higher than
predicted ROI.
Flammability
Isopentane is a highly flammable substance and this may cause accidents that were not
expected. The container that will be required to store the final product would need to fit a
certain description.
First, it would have to be designed to ensure that it can be tightly sealed to prevent any
leakages that would lead to escapes that would be fatal.
Drain access should be limited within the storage or production area to prevent the spread
of the chemical if a spillage ever occurred. The steps above may not be satisfactory enough,
therefore, one has to take care of a situation whereby a fire may occur.
If leakage does occur, incandescent materials should not be found within the vicinity. For
they carry heat, the fire will most definitely occur due to the contact with the highly flammable
substance. Alcohol-resistant foam and Carbon dioxide extinguisher should be placed within
the vicinity for they are the most suitable standard grade extinguishers for this job.
Bodily Harm Due To Contact
Protective gear would have to be used whenever one is handling the liquid and dealing
in its environment.
Proper ventilation systems that are well regulated should also be built for the facility.
Automation that can seal off these rooms whenever an accident may occur should become
standardized too.
Recovery chambers where one has access to fresh air within the plant or somewhere near
should be recommended in case someone inhales the gas. The rooms should also be equipped
with showers and sinks. One may come in contact with the chemical and would have to rinse
it thoroughly before having to do anything else.
Environmental Hazard
Disposal of the material as it is could lead to potentially hazardous ecological outcomes.
If dumped into water bodies, the accumulation may ail the community and cause unprecedented
illnesses. Accurate data on the effects on animals are not available. Environmental preservation
will also give a better work area.
Issues That Could Arise From Poor Liquid Storage And Handling
Proper storage ensures safety of entire facilities of operation and workers. Improper
storage could lead to explosions if dealing with highly flammable liquids that are also volatile.
An accident of such proportions can only be sorted out by insurance or proper company
planning for accidents. Avoidance of such a situation is easy with proper planning and
implementation of safety measures.
Other issues
Events
Consequences
Mitigation
Liquid Leak
Aerosolization of the liquid and The room should also have the
causing poisoning of workers and capability to be completely sealed off
locals in the area.
so that cleaning may occur by use of
non-combustible absorbent material
such as sand or earth.
Ecological Impact
Death of animals, people and plants.
Waste disposal facilities should build
a partnership with this plant and
environmental cleaning protocol put
in place.
Process Engineering Team
Subject: Preliminary Design Report
We are pleased to inform you that the proposed addition to the plant in which we would
convert n-pentane to iso-pentane and sell the iso-pentane as a 95% purity product will give our
plant enough revenue to justify continuing the development of the process. This has been
discovered through the thorough economic analysis of the capital cost as well as the operating
cost of the new additions needed for the plant. The return on investment is at about 30% and the
threshold to move forward should be about 15%. Through the ASPEN simulations as well as the
cost analysis, the threshold will easily be met.
The goal of this project is to convert n-pentane to isopentane through a reaction and a
catalyst that the R&D team had found. This process involves building a new section of the plant.
The process we have come up with involves a reactor, a few distillation columns, a flash drum,
and a bunch of compressors and heat exchangers. Hydrogen is also used to protect the catalyst
from coking and must be at least at a 2:1 ratio to the feed stream. The feed stream being
purchased contains a mixture of hydrocarbons including butanes, pentane, hexane, benzene,
heptane, and trace amounts of components lighter than butane and heavier than heptane. We are
able to purchase the feed at about 300 MM lb/yr. Similarly, the hydrogen being bought contains
contaminants of methane and ethane. The purity of the product should be 95% isopentane. The
reaction used is an equilibrium reaction and has a side reaction which creates byproducts. The
byproducts created from the reaction are methane, ethane, propane, and butane.
As the process currently stands, there are two feed streams. The first feed stream is the
feed that we are purchasing with pentanes and some other hydrocarbons. The other feed stream is
the hydrogen feed. This stream is also being purchased and is used to prevent coking of the
catalyst for the reaction to separate the isopentane from the n-pentane. The feed stream is coming
in as a liquid at ambient temperature and pressure and the reaction needs to take place at 250 psia
and 800°F. The feed stream is therefore sent to a vaporizer which brings vaporizes the stream so
that it can mix with the hydrogen stream. Meanwhile, the hydrogen stream is sent to a
compressor so its pressure is high enough to flow through the system. The two streams are then
mixed and sent to a fired heater to get to the right temperature for the reaction. After the fired
heater they are sent to the reactor and the reaction occurs.
Next, coming out of the reactor, the stream must be cooled down using a heat exchanger
and then a flash drum to get rid of excess light components. These light components are then sent
back to the beginning of the process to be recycled to cut down on not only the cost of hydrogen,
but also the loss of any isopentane. The heavier stuff comes out the bottom of the flash drum and
is then sent to a series of distillation columns. The first distillation column separates anything
lighter than isopentane off the top. The second distillation column separates anything heavier
than n-pentane off the bottom. The bottom stream with the heavy components is then sent to
another distillation column which recovers any lost isopentane and recycles it back into the
system while the bottom is used for fuel for the fired heater. The final distillation column
separates isopentane from n-pentane and isopentane is taken off the top as product while the npentane is recycled back into the process.
Upstream:
The process starts with two feed streams, one that contains the pentane and one that
contains the hydrogen. The pentane stream is coming in from several choices of potential buyers
that consist of petroleum refinery operations in the area and consist of industrial grade mixed
pentanes that are contaminated by small amounts of lighter and heavier hydrocarbons. A low
purity pentane feedstock was chosen as it is cheaper and the impurities did not affect the catalyst
performance. This feed stream contains 4% butane, 74% n-pentane, 8% isopentane, 6% hexane,
2% benzene, and 6% heptane and larger. The amount that was chosen to purchase was 300
MMlb/year because any larger quantities would have to be purchased on the open market and
would therefore cost more as we would have to outbid other buyers. As such, the maximum
amount of pentane at the market price was chosen. However, because the plant will only be
running for 90% of the year, the 333.33 MMlb/year was used for the simulation to make up for
it. This stream will also be coming in at atmospheric conditions which means 75°F and 16 psia
and be initially stored in a tank for use. This stream is simply labeled as Feed on the flow
diagram.
From the tank, the stream is immediately taken to a pump that will bring the discharge
pressure up to 280 psia. This, as a result, will bring the temperature of the stream to 77.78°F and
require a power of 33.12 hp. This pump is used to bring the stream to an appropriate pressure to
allow for flow throughout the entire system and accounts for all of the pressure drops throughout
the plant. It was also brought up to a pressure that accounts for the pressure drops to the reactor
as the reactor should be at a pressure of 250 psia. It is simply labeled as Pump with the exit
stream labeled as HP-pent.
Because this stream is still a liquid and will need to be mixed with the hydrogen stream
which is a gas, the stream must be converted to the vapor phase using a vaporizer. The
subsequent temperature that allowed for a molar vapor fraction of 1 was 339.59°F and accounted
for a pressure drop to 270 psia and a heat duty of 9.97 MMBtu/hr. The vaporizer is labeled as
Vap and the outlet stream is labeled as PentVap. The outlet stream combines with the hydrogen
stream and two recycle streams.
The other stream is the hydrogen stream which will be bought from Ajax Refining as
their operations produce a byproduct stream of hydrogen. Because they are close by, the stream
will be delivered by pipeline and then stored in tanks as well. This means that the stream will be
at 75°F but will already be pressurized to 150 psia. As for the amount, the R&D team has
determined the correct amount of hydrogen that is needed to protect the catalyst from coking.
They determined that the ratio of hydrogen to pentane should not fall below 2 as some carbon
deposition was detected during their runs. However, the runs were not long enough to observe
any significant loss in reactivity or whether the catalyst would coke up entirely. Hence, a ratio of
2:1 was chosen which means a flow rate of 2.1 MMlb/year. Because this stream is produced
from a catalytic reforming operation, there are some impurities which means a cheaper price but
these impurities may cause a problem if removing the impurities is too expensive. This stream
contains 80% hydrogen. 15% methane, and 5% ethane. This stream is labeled as H2 on the flow
diagram.
This stream needs to be brought up to the same pressure as the pentane feed stream so an
isentropic compressor, labeled Comp, was put in that will bring the discharge pressure to 270
psia. It has an isentropic efficiency of 0.7 and requires 16.54 hp. This also brings the outlet
stream, labeled HP-H2, to a temperature of 203.2°F.
After the compressor, the stream is brought to a mixer, labeled Mixer, that combines it
with the pentane stream described previously and two recycle gas streams that are described in
the recycle stream section. The combined stream, labeled HtrFeed, will have a temperature of
519.72°F.
For the reactor, the R&D team has determined that the most promising runs in the reactor
were a high pressure gas phase reaction at 800°F and 250 psia. Therefore a fired heater was put
in place to bring the temperature to 800°F. A further pressure drop was accounted for meaning
an outlet pressure of 255 psia. The resulting heat duty for this heater was 106.2 MMbtu/hr. This
is labeled as the FiredHtr and goes to the reactor next.
Initially, an equilibrium reactor, Rxr, was set up at 250 psia and a duty of 0 Btu/hr and
used a 1:1 reaction of n-pentane to isopentane. From this, a mole fraction of isopentane was
found and then, another reactor was made with a fraction conversion that allows for a mole
fraction that is slightly lower than that of the equilibrium reactor. While only one reactor will be
used in the actual plant, two are being used to simulate the reactor. The first, Rxr2 is for the 1:1
reaction of n-pentane to isopentane while the second, SideRxr, represents the side reaction. This
first reactor has the same condition at 250 psia and a duty of 0 Btu/hr. This also means a mole
fraction 0.0549 while the equilibrium mole fraction of 0.0609. As a result, a fraction conversion
of 0.36 was chosen to allow for this lower value. This value can also not be too low as the
fraction conversion plays a large part in the purity of the end stream. The inlet and outlet streams
of this reactor are RxrFeed2 and Rxr2Prod respectively.
While the R&D lab has determined that to prevent any carbonization of the catalyst,
hydrogen must be incorporated into the feed. However, the catalyst produces side reactions as
the hydrogen reacts with the pentane removing a methyl group. This reaction is as follows, C5H12
+ H2 ? C4H10 + CH4. In addition, the butane that is produced will perform the same reaction
with C4H10 + H2 ? C3H8 + CH4. This will then be repeated for the propane that is produced and
then the ethane that is produced. These reactions are also irreversible and proceed at a slower
rate to the main n-pentane to isopentane which means that a small amount is made. The R&D
team determined through lab experiments that 2% of the pentane entering the reactor is
converted to the side products. These side all occur simultaneously and hence, the exact
proportions are difficult to obtain. To counteract this, the leader of the R&D team said to model
the side reactions as a single reaction with about the same ratios of byproducts that were
determined in the lab. This single reaction is much either to model as one reactor than as several
reactors. However, this reaction will have actual ratios of the byproducts that are different but
should be approximately the same values. This new reaction is as follows, C5H12 + 1.3125 H2 ?
0.3125 C4H10 + 0.5 C3H8 + 0.75 C2H6 + 0.75 CH4. This reaction occurs with the n-pentane and
the isopentane produced from the main reaction. Hence, a fraction conversion of 0.01 was
chosen for each of the 2 side reactions. The outlet stream of the reactor, SideRxrP, then goes to a
series of heat exchangers in the downstream.
Downstream:
The next seven heat exchangers were all made using heat economy in mind which means
that they are at other places in the process as well. Because this stream is coming out of the
reactor at 800°F, it can be used to heat up other areas of the process. The first heat exchanger is
one on the lights recycle stream and is talked about in the recycle section. It brings the
temperature down to 533°F. The second is actually the vaporizer talked about previously in the
upstream and brings the temperature down to 504°F. After that, there are the four reboilers on the
distillation columns. The first is the stripper’s reboiler and brings the temperature down to
383°F. Then, the reboilers of Hvy-Pent, Hvy-Rec, and I-N-Pent bring the temperature of the
stream down to 356°F, 355°F, and 223°F respectively. These distillation columns are talked
about later in the downstream process. The last heat exchanger that uses heat economy is on the
pentane recycle stream and brings the temperature down to 194°F. A pressure drop of 2 psia was
used for each of the exchangers. These heat exchangers are, in order of being talked about, HX2,
Vap, StprBoil, HvyBoil, RecBoil, PentBoil, and HX1.
Then a condenser, labeled HX, is used to condense some of the stream to a liquid and
therefore a temperature of 100°F and a pressure of 232 psia. However, this only results in a
molar liquid fraction of 0.2934. Because heat economy was used in this stream, the required duty
was only 56.23 MMBtu/hr. The outlet of this heat exchanger is HP-Prod.
As stated previously, the heat exchanger outlet stream, HP-Prod, goes into the flash
drum which is used to separate the vapor and liquid phase. The vapor stream is labeled Flashgas,
which is talked about in the recycle stream section, and the liquid stream is labeled Flashliq. This
is in place to separate all of the hydrogen and some of the methane from the rest of the stream as
the hydrogen is basically impossible to condense to a liquid. The liquid coming out of the bottom
of the drum is sent to the stripper column.
This stripper column, labeled Stripper, is used to separate propane and everything else
lighter from the rest of the stream. This works by having the stream enter the top of the stripper
at which point the remaining gas from the stream is immediately separated from the stream by
simply exiting the top of the column, labeled Lite. Because of this, there is not a condenser at the
top of the column. The remaining material then travels down the column like a normal
distillation column with a reboiler at the bottom. In this case, a kettle was used as the reboiler
and the resulting duty was 39.88 MMBtu/hr. The number of stages used was 30 with a bottoms
to feed ratio of 0.19 which resulted in a reflux ratio of 1.63. These values were chosen to remove
most of the lights and to result in the desired purity of the end isopentane. The results of this
stripper showed that the bottom stream, IPLiq, had lost all of the propane, ethane, methane, and
hydrogen with the majority of the stream being made of isopentane and n-pentane.
This bottoms stream then flows into a distillation column, labeled Hvy-Pent, which is
being used to separate the heavies from the stream. This includes everything heavier than the npentane. The number of stages for this column was chosen to be 22 with a component recovery
for the n-pentane of 0.99 and for the hexane of 0.01. This resulted in a reflux ratio of 0.913 and a
distillate to feed ratio of 0.91. The inlet flow is coming in at the 12th tray from the top. The
pressures for the condenser and reboiler were set to 43 and 45 psia respectively so that the
temperature for the condenser was at 150°F. This allowed for cooling water to be used to its
fullest as it comes in at 80°F and can leave at a max of 130°F. The duty required for the reboiler
and the condenser were 8.67 and 14.85 MMBtu/hr. The duty generated in the reboiler was used
to cool down the stream that exits the reactor. The bottom outlet stream, labeled Hvy, contains
less than 1% isopentane with the majority of the stream being made of heptane and then hexane.
However, the stream contains about 5% n-pentane so a new distillation column was put in place.
This steam exits at 242°F, while the tops stream, labeled Pent, exits at 151°F and contains almost
entirely n-pentane and isopentane as only about 1.3% is made of the other components.
The new distillation column that was made is labeled Hvy-Rec and is used to separate
any remaining pentanes and then send them to combine with the top product of the Hvy-Pent
distillation column. The bottoms are then serve as fuel gas for the fired heater. By using npentane and hexane recovery of 0.99 and 0.01 respectively, the resulting column has 18 stages,
which meant a reflux ratio of 1.76, with the feed coming in at the 10th stage. The reboiler and
condenser pressure were set to 36 and 38 psia so that cooling water could be used as the
temperature would be 151°F. This would put the temperature of the stream out of the reboiler at
236°F. Similar to the other columns, the stream exiting the reactor was used as the heating
source in the reboiler. The duty of the reboiler and condenser were 87 and 130 kBtu/hr
respectively. The top stream, HvyRec1, combines with the top stream, Pent, of the previous
column in amixer labeled PentMix. The exit stream Pent2 leaves at a temperature of 139°F and
goes to the final column.
This final distillation column is used to separate the n-pentane from the isopentane. The
stream that is exiting this column at the top, labeled IPent leaves at 151°F and is the end product
of the plant. By running the colum…
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