Essay: Pre-Reflection for CHE 432 Assignment: Understanding Chemical Processes in Industry



Pre-Reflection

CHE 432 Assignment 1

I am completing this work in order to better understand chemical processes in industry. I will also learn where important online and physical resources can be found and how to use them on future assignments in this course. I will be completing this assignment from August 18, 2018 to August 31, 2018.  I will be doing this work for Dr. Veronica Burrows as part of the CHE 432 course, Principles of Chemical Engineering Design. This assignment will be the first of five for the semester.

This work will help me to achieve my goal of completing my B.S.E. in Chemical Engineering. I also think this assignment will help me get back into the swing of things after taking off a year of school to work at an internship. I believe this assignment will help refresh my memory about proper formatting and improve my professional writing skills. This assignment specifically will allow me to better understand how a specific product is made and get me thinking about process design. This will meet the instructor’s goal of students applying previous course knowledge to a process design and scale process equipment dependent on the specified dimensions. Additionally, I will gain a better understanding of cost of a design based on equipment cost and develop a flow diagram to describe the process.

I will most likely use my organizational skill to work on this project and properly keep track of citations and information learned. I will also use my previous chemical engineering course work knowledge. I believe that the concepts I learned in Reactor Design and Fluids will probably be the most used for this assignment. I also believe that my knowledge from my business minor may come in handy when it comes to estimating costs and financial analysis.

I will draw on my strength of organization to keep on top of this task and properly organize my citations. This will make it easier to complete the assignment so that I am not back tracking at the end of the project trying to figure out what sources I used two weeks prior. I will also use my strength of time management to divide up the work. This will also help me avoid my weakness of my currently sprained wrist since it can only stand to type in small quantities of time before tiring or getting agitated. It will also help me avoid my weakness of getting overwhelmed with the amount of work I have left.

I think this assignment will probably be very successful as I am starting it early. I am most worried about remembering and properly executing all of the formatting requirements for this course. Since I have not worked on Chemical Engineering for over a year I do see knowledge being a hurdle as I may not remember everything right away. I could see myself getting stuck on simple concepts just because they have escaped my memory.

This work will allow me to properly complete this course as well as how to understand on a basic level what it means to be a process engineer. I believe this assignment is the first time I have looked at a full process design from start to finish of a product. Furthermore, this assignment will allow me to complete this course and move on to my final semester in Chemical Engineering. This will then allow me to complete my undergraduate degree and move on to my master’s degree. I will then be able to complete my master’s degree and get a job.

Report

In this report Monoethanolamine (MEA) will be examined from reactant sources to reactants to finished products MEA is used in. The raw materials used to make MEA will be discussed. Two different process flow diagrams are included that cover the process of making MEA and a process it is used in to make consumer goods. Environmental issues and process safety as it relates to the production of MEA will be reviewed. As well as economic information related to MEA.

MEA is unique because of its chemical structure and can have reactions similar to both amines and alcohols.1 Figure 1 shows the chemical structure of MEA. There is both an alcohol and primary amine group.2 Physical properties of MEA include it being colorless and either a viscous liquid or a solid.3 The molecular weight of MEA is 61g/mol.1

Figure 1:MEA structure adapted from [1]

Table one below has the Chemical properties of MEA included.

Table 1: Chemical Properties of Monoethanolamine(data from DOW Monoethanolamine1)

Property Value

Boiling Point (760 mmHg) 170C

Flash Point – Closed Cup 96C

Flash Point – Open Cup 104C

Freezing Point 11C

Specific Gravity (H2O=1) 1.017 at 20C

Vapor Density (air=1) 2.1

Vapor Pressure 0.2 mmHg 20C

During the production of MEA two other products are produced as by products known as diethanolamine (DEA) and triethanolamine (TEA). Below in Figure 2 DEA is shown.

Figure 2: DEA structure adapted from [4]

DEA has is very similar to MEA, however there is another carbon chain with an alcohol group on the end. DEA is typically an “oily colorless liquid or solid white crystal.”4 It is known to smell like ammonia or rotten fish.4 The molecular weight is 105.4 g/mol.4

Table 2 shows the chemical properties of DEA.

Table 2: Chemical Properties of Diethanolamine(data from PubChem4)

Property Value

Boiling Point (760 mmHg) 127C

Flash Point – Closed Cup 168C

Freezing Point -6C

Vapor Density (air=1) 2.1

Vapor Pressure 3.5 mmHg 20C

The third product associated with MEA is TEA. TEA has three sets of carbon chains stemming from a Nitrogen atom all ending in an alcohol group.

Figure 3: TEA structure adapted from [5]5

TEA can be found as a liquid or viscous liquid with a molecular weight of 149.188 g/mol. Table 3 examines the chemical properties of TEA.

Table 3: Chemical Properties of Triethanolamine(data from Dow6)

Property Value

Boiling Point (760 mmHg) 117.8C

Freezing Point -42C

Vapor Density (air=1) 2.4

Vapor Pressure 7.2 mmHg 20C

As molecular weight increases both the boiling point and the freezing point decrease. However, the vapor density increases and the vapor pressure increase. These trends are to be expected and explain that depending on the intended use the similar chemicals of MEA, DEA, and TEA can be selected.

MEA is not directly used by consumers, but it is in products consumers purchase and use regularly.7 Consumer uses of products containing MEA include detergents, personal care, textile finishing, and wood treatment.1 49% of all MEA produced is used for scrubbing to condition gas.3 About a quarter of what is made is used for petroleum and gas conditioning.3 Uses of MEA in industry also include wood treatment and as solvent to separate sulfur containing molecules from refinery gas. 8 MEA can also be used in a flue gas stream to remove CO2. It is also able to be recycled in this process and therefore, it is economical to use MEA.9

There are many distributors of MEA in the country. One of the producers is TRInternational, Inc. in Seattle, WA.10 Another company, Seidler Chemical, part of the Maroon Group also produces MEA in Newark, NJ.11 Finally, Spectrum Chemical MFG Corp, also produces MEA in Gardena, CA and New Brunswick, NJ.12 MEA is a commodity chemical as it is produced by many companies and is in abundance.13

The Ethanolamine market is a growing market. In 2014 the value of the market was said to be $4.2 billion. It was predicated to be $5.5 billion in the following year in 2015.14 This means the amount produced in 2014 was 5.19 billion lbm and predicted for 2015 was 6.79 billion lbm. Additionally, ethanolamine does not cost much to produce so has become a globally made commodity.14 The, “Worldwide capacity for ethanolamines was 2.374 million metric tonnes (5.23 billion pounds) in 2011.”15

 

The most common raw materials used to create MEA are ammonia and ethylene oxide.16 Ammonia is mass produced all over the world. H2 and N2 are combined to create ammonia.17  The hydrogen gas can be produced from natural gas18. Natural gas undergoes a petrochemical drilling process from deep underground.19 Natural gas consumption has increased steadily since 2000.19 In 2016 about a quarter of all dry natural gas produced in the United States came from Texas. Pennsylvania followed with 20%, Oklahoma with 9% and Louisiana with 6%.19 To obtain the nitrogen gas, air is captured and then goes through a membrane process to separate nitrogen and oxygen.20

Ethylene Oxide is also a component that undergoes a chemical process that starts out as air. Other products of this process include fuel gas and waste water. The inputs include air, ethylene, and process water.21 The water comes from a water purification plant (originally from a lake, glacier, etc.), the ethylene comes from natural gas and petroleum.22 Petroleum comes from the ground in states such as Texas, California, Louisiana, and Oklahoma that all have petroleum refineries.23

Figure 4 features the process flow diagram for MEA, DEA, and TEA.16 (Veronica Burrows, personal communication.)

Figure 4: MEA, DEA, and TEA process flow diagram adapted from [24]

Ammonia and Ethylene Oxide enter the system and are combined at a node in the pipes before being pumped and heated into a CSTR. The mixture goes into a flash separator to remove the ammonia so that it can be reused in a recycle stream. The remaining product from the separator heads to a distillation tower. Called the “Mono Tower” in the process because it separates out the MEA. Two additional towers follow called the “Di” and “Tri” tower because they distill the DEA and TEA product.24

Equations 1, 2, and 3 listed below are the major reactions happening within the CSTR. The reaction most likely happens with excess ammonia in order to have enough to recycle as well as enough to make MEA, DEA, and TEA.

C_2 H_4 O+NH_3→C_2 H_7 NO

(1)

〖2C〗_2 H_4 O+NH_3→C_4 H_11 NO_2

(2)

〖3C〗_2 H_4 O+NH_3→C_6 H_15 NO_3

(3)

The most major change in each equation is the ratio of ammonia used to produce MEA (Equation 1), DEA (Equation 2), and TEA (Equation 3).

MEA as discussed previously is not a good that consumers directly use, however it is in their everyday products. MEA can be “used as a surfactant.”3 Surfactants work well to clean because they are repelled by water, but attracted to oils and fats. This makes them very good cleaners.25,26 Figure 5 shows the process flow diagram of a detergent.27 (Veronica Burrows, personal communication)

Figure 5: Detergent process using surfactants [27]

As discussed previously MEA is used as a surfactant which is utilized in this process. First phosphate, silicate, and dry scrap are mixed together, then mixed with the surfactant. This entire mixture then enters a crutcher.27 A crutcher is an effective mixer which can combine liquids and solids together. It acts similarly to a washing machine.28 The output is put in a drop tank and then pumped into a spray tower. A furnace is used to heat the spray tower. The products are then moved to cyclones to “recover powder products.”29 The output is then moved to a screen and then a perfume mixer for scent. The final result is detergent.

In chemical engineering an important consideration to any process is the environmental impact that the process that is designed possess. Ammonia and ethylene oxide are the two major components to produce MEA both come from petroleum and/or natural gas. The process to obtain both of these components has a large amount of pollution associated with it as fracking is not an environmentally friendly practice.17,19

The production of MEA comes with emissions of carbon dioxide. Carbon dioxide can interact with Nitrogen and create carcinogens. Currently research is being conducted to absorb carbon dioxide using MEA. Carbon dioxide is a by-product when making ammonia. Therefore, the more ammonia that is made and used for MEA the more CO2 is being released. The process of making ammonia also uses a large amount of energy.30

In humans MEA should not come in contact with the eyes or skins as it can create burns. It is listed as corrosive to the skin. Inhalation can cause damage to the entire respiratory system. If MEA is ingested internal chemical burns can occur.15

MEA can be harmful to aquatic life in large quantities which can create toxic compounds when mixed with water including nitrosamines, and nitramines15. If a large quantity is released into water the pH can be affected and cause toxic shock to species using the water source. It can also affect waste water treatment facilities and can create unwanted odors when mixed with sewage.15

MEA, DEA, and TEA can harm the environment because of industrial waste water used in the process. Often times, chemical plants are placed near sources of water which is where industrial waste water may be let out. A study was conducted on different species of bacterium, algae, crustaceans, and echinoderm. The study looked at how MEA, DEA, and TEA in the water affected each of these species. TEA was the harshest to the species immobilizing crustaceans and inhibiting bioluminescence in bacterium. Therefore, more research should be done in this are to protect fresh and salt water species from harm.31

A major process safety concern comes from the use of ammonia. Ammonia is not flammable under pressure as a liquid. It can ignite or cause an explosion if a big source of energy occurs. There is a danger of a confined space explosion.32 Deflagration can occur and cause an explosion. This is especially important to monitor within the CSTR as that unit is heated up. Therefore, it is important to have monitors on all units as well as back up monitors. An unusual temperature or pressure increase could lead to an explosion. Therefore, it is best for any plant using ammonia not be located near to residential areas. There should be a buffer zone.33

Additionally, the reaction between ammonia and ethylene oxide is an exothermic reaction. Therefore, there is a chance of a runaway reaction taking place. Runaway reactions can occur because of “mischarged raw materials, failure of a reactor’s cooling system, or the presence of contaminants.”33 The environment, workers, and the public can all be hurt if a “sudden energy release from…an uncontrolled reaction,”33 takes place. In order to prevent runaway reactions, it is best to thoroughly understand the reaction and reaction mechanisms while designing a plant. Runaway reaction can occur in a short amount of time due to over pressurization by a byproduct.33

When training it is best to make sure there are multiple safeguards in place. Human error does happen, but one error, “should not lead to a catastrophic release.”33 Relief systems should be put in place. Training on SOPs and review training is important to assure all employees understand how operation should occur. Additionally, accident history is critical to learn from the mistakes of other plants so as to not incur the same result again. An emergency relief system should be put in place in case of an emergency.33

Another important concern when it comes to process design is the economics behind the plant. It is important to understand what the product goes for, how much the reactants or raw materials cost and how much each process unit costs.

Using the book “Rules of Thumb in Engineering Practice,” cost estimates (FOB) range by about ±30%. Since the book was written in 2007 that range could be even larger.34 The centrifugal pump would cost $7000 for a typical 1800 rpm, 15m head. The pump would have a drive power of 16kW.34 There are other costs associated with pumps and other options for exact specifications. This is only one option of selection of pump specifications.

For a reactor in the process a jacketed and agitated CSTR would be preferred as the temperature could be controlled and the CSTR needs an agitator to stir. The reactor volume chosen was 4,000 gallons with a vessel pressure of 150 psi. The material used should be stainless steel, 304 as it does not react with ammonia, the most reactive of the species in the process. The cost in 2014 for this reactor in the United States was $378,100. If, however, the plant is located near the ocean and could be exposed to salt water then stainless steel, 316 should be used which costs $459,200.35,36

In the industrial use of MEA as a surfactant a furnace is used to heat the spray tower. For a fired box furnace with “horizontal radiant c/s tubes” with 10MW heat absorbed ranging from 2-100MW the cost is $1.5 million dollars.34Additional costs can be added based on the alloy inside the furnace and pressure factors.34

The commodity price of MEA was between $1,897 and $1,949 per tonne which is equivalent to $0.86 to $0.88 per lbm in May of 2013. Related products DEA and TEA were valued between €1,140-1,190/tonne and €1,500-1570 tonne, respectively. Which is equivalent to $0.67 to $0.70 per lbm and $0.88 to $0.92 per lbm, respectively. 37  Since MEA, DEA, and TEA are commonly produced together it is important to examine the price of all three.

The commodity price of ammonia on August 20, 2018 was $281/ton or $0.14/lbm. The retail price is $484.38 Therefore, there is a large difference between the commodity and retail price. The commodity price for Ethylene Oxide was about $11/tonne in August 2011.39 Therefore, Ethylene Oxide is a very cheap chemical as it costs about $0.005 per lbm.

References

[1] DOW. DOW Monoethanolamine http://msdssearch.dow.com/PublishedLiteratureDOWCOM/dh_098c/0901b8038098cd2d.pdf?filepath=amines/pdfs/noreg/111-01410.pdf&fromPage=GetDoc (accessed Aug 21, 2018).

[2] Block, E.; Smith, P. A. S. Amine Chemical Compound https://www.britannica.com/science/amine (accessed Aug 21, 2018).

[3] Monoethanolamine https://pubchem.ncbi.nlm.nih.gov/compound/Ethanolamine#section=Top (accessed Aug 21, 2018).

[4] Diethanolamine https://pubchem.ncbi.nlm.nih.gov/compound/diethanolamine (accessed Aug 30, 2018).

[5] Triethanolamine https://www.sigmaaldrich.com/catalog/product/sigma/90279?lang=en&region=US (accessed Aug 31, 2018).

[6] Triethanolamine, Commercial Grade LFG 85 https://www.dow.com/webapps/msds/ShowPDF.aspx?id=090003e8806f26cd (accessed Aug 30, 2018).

[7] DOW Specialty Amines- https://www.dow.com/amines/prod/ethano-mea.htm (accessed Aug 30, 2018).

[8] Ethanolamine applications http://www.intermediates.basf.com/chemicals/ethanolamines-ethyleneamines/applications-ethanol (accessed Aug 30, 2018).

[9] Abu-Zahra, M. R. M.; Schneiders, L. H. J.; Niederer, J. P. M.; Feron, P. H. M.; Versteeg, G. F. Int. J. Greenh. Gas Control 2007, 1 (1), 37–46.

[10] Product Details: Monoethanolamine (MEA) http://www.trichemicals.com/products/product-detail/Monoethanolamine_(MEA) (accessed Aug 21, 2018).

[11] Monoethanolamine http://www.seidlerchem.com/monoethanolamine.htm (accessed Aug 21, 2018).

[12] Monoethanolamine, NF https://www.spectrumchemical.com/OA_HTML/chemical-products_Monoethanolamine-NF_M1322.jsp?minisite=10020&respid=22372&phrase=Monoethanolamine (accessed Aug 21, 2018).

[13] O’Lenick, T. Comparatively Speaking: Commodity vs. Specialty Chemical https://www.cosmeticsandtoiletries.com/research/chemistry/3573772.html (accessed Aug 22, 2018).

[14] K, C. Global Ethanolamine Market Worth $5.5 Billion by 2019; Fort Worth, 2015.

[15] Product Safety Assessment DOWTM Monoethanolamine; 2015.

[16] Ethanolamines (MEA, DEA, TEA) production from ammonia and ethylene oxide http://www.inclusive-science-engineering.com/ethanolamines-mea-dea-tea-production-from-ammonia-and-ethylene-oxide/ (accessed Aug 22, 2018).

[17] Pattabathula, V.; Richardson, J. Introduction to Ammonia production https://www.aiche.org/resources/publications/cep/2016/september/introduction-ammonia-production (accessed Aug 22, 2018).

[18)] HydroGEN http://www.gulfgases.com/H2GenerationPlts_PFD1.htm (accessed Aug 26, 2018).

[19] US Department of Energy. Natural Gas Explained https://www.eia.gov/energyexplained/index.php?page=natural_gas_where (accessed Aug 26, 2018).

[20] N2-O2 Membrane http://www.gulfgases.com/N2O2MembraneUnits.htm.

[21] Energy Balances and Numerical Methods; 2002.

[22] Carey, F. A. Ethylene https://www.britannica.com/science/ethylene (accessed Aug 26, 2018).

[23] U.S. Energy Inf. Adm. 2014.

[24] Kk, S. Ethanolamines production by reacting ammonia and ethylene oxide http://www.inclusive-science-engineering.com/process-technology-to-produce-ethanolamines-by-reaction-of-ammonia-and-ethylene-oxide/ (accessed Aug 30, 2018).

[25] Soaps & Detergents: Chemistry (Surfactants) https://www.cleaninginstitute.org/clean_living/soaps__detergents_chemistry_2.aspx (accessed Aug 29, 2018).

[26] What are surfactants?

[27] Yuan, W. M.; Qi, S. W.; Hao, L. Z. Organic Chemistry about Soap and Detergent http://aliceinchemiland.blogspot.com/2013/03/organic-chemistry-about-soap-and.html (accessed Aug 30, 2018).

[28] Sanghavi, H. Soap Crutcher https://www.indiamart.com/proddetail/soap-crutcher-7832717655.html (accessed Aug 30, 2018).

[29] Zenz, F. A. CYCLONE — DESIGN TIPS https://www.chemengonline.com/cyclone-design-tips/?printmode=1 (accessed Aug 30, 2018).

[30] Luis, P. Sci. Direct 2015, 93–99.

[31] Libralato, G.; Volpi Ghirardini, A.; Avezzù, F. J. Hazard. Mater. 2009, 176, 535–539.

[32] What are the hazards of working with Ammonia? https://enviromed.ca/index.php?id_cms=28&controller=cms (accessed Aug 29, 2018).

[33] How to Prevent Runaway Reactions https://archive.epa.gov/emergencies/docs/chem/web/pdf/gpcasstd.pdf (accessed Aug 30, 2018).

[34] Woods, D. R. Rules of Thumb in Engineering Practice; 2007.

[35] Selection of stainless steels for handling ammonia (NH3) https://www.bssa.org.uk/topics.php?article=36 (accessed Aug 30, 2018).

[36] Reactor Cost Estimate http://matche.com/equipcost/Reactor.html (accessed Aug 30, 2018).

[37] Price and market trends: Europe May ethanolamine prices move down on feedstock fall https://www.icis.com/resources/news/2013/05/31/9673987/price-and-market-trends-europe-may-ethanolamine-prices-move-down-on-feedstock-fall/ (accessed Aug 29, 2018).

[38] Knorr, B. Fertilizer Outlook – Fertilizer costs take another step higher https://www.farmfutures.com/story-weekly-fertilizer-review-0-30765 (accessed Aug 29, 2018).

[39] Finch, H. Ethylene Oxide (EO) Prices and Pricing Information https://www.icis.com/resources/news/2007/11/05/9075771/ethylene-oxide-eo-prices-and-pricing-information/ (accessed Aug 29, 2018).  

Post-Reflection

CHE 432 Assignment 1

Overall, I am satisfied with the end result of this project. It worked well for me to break up the work as well as start working on the assignment well in advance of when it was due. This gave my wrist time to rest in between typing so that I was not worried the night before because my wrist was freezing up and would not type. Working ahead also gave me time to brush up on topics I did not remember.

I wish I had known that I would not procrastinate this assignment because I was stressed that I would not be able to get it done in time but am happy that I was able to do so. I also learned that if I take a break and come back to an assignment later I am more likely to be able to get it done in a shorter amount of time and more successfully. I also felt as though I was not as familiar with the data bases as I remember so I will have to go back and brush up on them in order to do better on future assignment. On future assignments I would use a larger variety of data bases as I may come upon the answer more quickly.

I used my strength of being organized to complete this assignment. It was helpful for me to organize the questions and my citations so that I was not scrambling right before I turned it in to make sense of all of my citations, notes, and references. In the past right before I turned in my assignment I was working on completing citations and this time I was actively writing them as I came across them. I did use my previous chemical engineering coursework to complete this assignment and looked up what I did not remember. I do not think my knowledge from fluids or my business minor came in handy for this assignment, but they may for another in the future.

I was able to avoid the weakness of my wrist by working on the assignment in small parts at a time so that at any one time I was not overwhelmed or unable to complete my assignment on time. I was also able to avoid my weakness of getting overwhelmed by the amount of work I had left to do. There was definitely knowledge I did not remember, but I took the time to relearn it or look up terms for which I forgot the definition.

As far as learning objectives I was able to use previous course work knowledge. I do believe I got an idea of how to size process equipment, but I do not entirely have that concept under my grasp. I was able to get equipment costs for a design. The hardest objective is the ability to design flow diagrams. I struggled to use ChemCad and the symbols offered with that package. If in class, we had explicitly gone over each symbol I would have learned more.

This assignment relates to my role as a professional engineer in order to design processes and how to write the beginnings of a report. This assignment relates to my non-University life, by teaching me to work ahead on assignments.

I learned how to look up information on specific process designs as well as the chemicals involved which will allow me to design my own processes in the future. I would like to get a better understanding of what symbols are matched with which units for process design. I would add some videos on how to use ChemCad and a list of process units and their symbols to the assignment. I would say my interest has stayed the same.