Mass and Energy Balance Essay

glomThe objective is to unveil a proposal for a chemic work out upon whole shebang which pass on be able to produce 550,000 gross tonne/year ammonium hydroxide victimisation LPG as the altogether visible. Different litigatees where researched and consequently fin whollyy one was picked, traveler reforming. This was decided to be the intimately viable and cost effective process using the raw sensibles we had available. The report explains in tip how the process works and all aspects of how the comprise pass on work including the mass and capacity brace crosswise the dress.What is ammonium hydroxide ammonia (NH3) is a stable sharpen and is utilize as a starting material for the make out of many important due north compounds and outho workout also be directly employ as fertilisers. It is produced by reacting hydrogen and nitrogen. It is a colourless heavy weapon with a sharp odour. The boiling point is -33.35oC and its frost point is -77.7oC.1 C be must be interpreted when handling ammonia pissing water as cease score deep burns in the skin impatience in the eyes and nose and when inhaled bath parkway coughing, sore throat and headache.2 There are opposite methods for the manufacture of ammonia. The troika main methods are locomote clean reforming, partial(p) oxidisation and electrolysis.Application and UsesAmmonia is a widely apply chemical in dia calculatedal types of industries. One of the main user of ammonia is the untaught industries for fertilisers. Around 80% of ammonia produced is for fertilisers such as urea, ammonium sulphate and ammonium nitrate.3 It is also apply as a building block for nitrogen containing compounds alike(p) nitric acid (HNO3). It is also apply in the fibres and plastics industry for the proceeds of acrylonitrile, melamine etc., and manufacture of explosives. Ammonia is also used in water treatment such as pH chasten and also in combination with chlorine to throw up industrial and municipal water supplies. Less commonly uses include as a refrigerant in compression and absorption governing bodys, manufacture of house donjon ammonia, in the food and beverage industry 4. word form 1 Pie map showing the uses of Ammonia.Market TrendsGlobally ammonia expenditures have been headed up due the large take in of fertilisers that are needed in the crop achievement to obtain high yield6. The circulating(prenominal) selling price of ammonia in Europe goes up to $600 per tonne7.Figure 2 Shows the global demand for Ammonia (D.a.NH3- treat application of Ammonia) As we can see from the chart the trend of ammonia demand globally is upward. It is say that the global ammonia market is to generate r stillues of approx. US$102 billion in 2019. As on that point is continous emergence in population in the developing countries the possible to cause demand for foodstuffs are to increase even yet. As the amount of agricultural land declines, ammonia-based nitrogen fer tilizers cater continue to gain importance in the incoming.9 So the demand of ammonia will ferment in the future which is shown in the chart. swear outesThere are many dissimilar processes confused in the ammonia production. The near common processes for ammonia are partial oxidation, steam reforming and electrolysis. From these 3 processes the best process driveway is so selected and that process would be most scotch and that meetes the design brief. partial oxidisationPartial oxidation involves the reaction of oxygen with burn down to produce hydrogen. The future(a) equations represent the partial oxidation of ethane, propane, barelyane and pentane. 10 ethane + O2 2CO + 3H2, C3H8 + 1.5O2 3CO + 4H2, C4H10 + 2O2 4CO + 5H2, C5H12 + 2.5O2 5CO+ 6H2There is no need for the cracking of LPG as they are light hydro carbon papers and can be used in partial oxidation.11 See Partial oxidation flow sheet (Reference 1 Partial Oxidation Flow Sheet)Hazards and Environmental ImpactT he main firing off is carbon dioxide which is a greenhouse gas and Partial Oxidation process emits more than carbon dioxide compared to steam Methane Reforming. Carbon dioxide emissions can be reduced by recycling it and selling it to urea and nitro-phosphate plants.13 No ammonia should be present in the air provided whitethornbe because of faulty equipment and maintenance activities, somewhat ammonia maybe released. Ammonia be bes explosive at the 16%-25% volume in air which could occur if in that location are any leakages in the ammonia fund facilities. It is also toxic by inhalation and pulmonic oedema can occur up to 48 hours after exposure and could be fatal.12 Nitrogen dioxide that is released is a toxic gas can be baneful when inhaled moreover can be avoided as can be detected because of the smell.The large amount of decompose water from this process is anformer(a) problem but there is a river near the Milford Haven site. in any case water pollution is a concern w hich may occur because of the suspended and dissolved impurities. It could also consider the aquatic life. Therefore the water must be treated in a full three stage water treatment plant in advance disposing it. 13 The disadvantage of partial oxidation is that the capital costs are higher for partial oxidation compared to any other process. It is estimated to be 100-120 cardinal for an annual production of 7.7 million GJ while for SR it will only be 70 million.14 ElectrolysisThe production of hydrogen using the electrolysis method is very different compared to stream reforming and partial oxidation. Electrolysis produces hydrogen by divide water into hydrogen and oxygen using volts of current to separate the hydrogen to one electrode and oxygen at the other in a cell. Oxygen is the byproduct in the process of producing ammonia which is valuable because it can be used in other chemical processes or sold to other companies for profit. In electrolysis there is no CO2 produced the refore there is no pollution.Standard electrolytic ammonia production energy consumption historically has been about 12 megawatt-hour. The fuel cost alone of making ammonia is $600 metric ton, and including capital and operating expenses that metric ton of ammonia cost about $800 to make. Compare electrolytic and using uses of inwrought gas as raw material the economically, for the past 100 years the cost of natural gas has not been higher than $1 and the fuel cost for a metric ton of ammonia from natural gas has been $30-$40. Figure 3 Ammonia Manufacturing ProcessFigure 3 Ammonia Manufacturing ProcessSteam ReformingGas purificationSyngas of a mixed bag of hydrogen, carbon monoxide, carbon dioxide and water can be broken down in to individual components and further cleansed through purification. The syngas will enter a channel reformer, which breaks down the carbon monoxide in to hydrogen and carbon dioxide using steam (H2O). Carbon dioxide is much more environsally friendly th an CO and can every be released in to the atmosphere or used in other steam reforming processes in the future.Desulphurisation randomness is a problem when carrying out steam reforming as it acts as a poison for the catalysts involved. It is important that this is outside prior to the syngas entering the system. The process is carried out in the presence of a catalyst, which is usually nickel. This nickel acts as an absorber for the sulphur, and so several catalyst-filled tubes within the system with a large internal surface area will allow the sulphur to collect to be abandoned of suitably.The ProcessHydrocarbons usually contain sulphur which ineluctably to be removed. The purification subsection is the first rear end of the whole steam reforming process. Feed is passed through tubes containing surface oxide. The sulphur in the feed reacts with the zinc oxide to produce zinc sulphide. This is to ensure that the feed travelling to the steam reformer does not poison the catalys ts in this section in any way. The catalysts used in the steam reforming process are nickel-based. These are easily poisoned by sulphur species.The purified feed is mixed with steam and then is passed to the primary reformer, which involves a nickel-based catalyst where the steam reforming process is carried out. Once the hydrocarbon is cleansed of sulphur, the reforming process can begin. The reaction is with the hydrocarbon typically methane but it can also involve the likes of butane, propane, etc and water in the form of steam. The reaction for methane (CH4) is shown below.CH4 + H2O 3H2 + COH = +251kJmol-1C3H8 + 6H2O 3CO2 + 10H2C2H6 + 4H2O 2CO2 + 7H2C4H10 + 8H2O 4CO2 + 7H2C5H12 + 10H2O 5CO2 + 16H2Reactions for other hydrocarbons, such as ethane (C2H6), propane (C3H8), butane (C4H10) and pentane (C5H12) are also shown, with their respective steam amounts required and the products gained. Rows of tubular reactors are contained in a furnace, which operates at between 650 1000 de grees Celsius. The hydrocarbon feed enters the system at a very high pressure, typically 20 30 bar. The process is carried out in the presence of a nickel-based catalyst which is packed into rounded tubes through which the steam/hydrocarbon gas mixture is passed. The catalysts act as surface for which the hydrocarbon will absorb and the steam. (Reference 2 Steam Reforming Flow Sheet)JustificationSteam reforming is the most viable proposition as we have all of the raw materials available within easy access, whereas if we were to use other processes, then we would have to source other materials e.g. we would need to source x no of kilowatts of electrical energy per year, for electrolysis. Mass reliefCp ValuesEnergy BalanceMaterial constitutesSimple Plant CostUsing a base of roughly 410 per ton of ammonia, and out designate at 550,000 tonnes, it would be assumed that the plant would produce 225,500,000 a year of ammonia. The Burrup plant in Australia was built at a cost of 457 mi llion and produces roughly 800,000 tonnes a year of ammonia. Using the 2/3 power rule, as follows, will allow the costs of the new 550k p/a plant to be shown. C = Cref(S/Sref)2/3C = 457000000 * (550,000/800,000)2/3C = 355,984,702The output of the new plant is 225,500,000, but the plant costs 355,984,702 to build, so it would take around a year and seven months for the plant to be profitable, based on an estimation without including the costs of the raw materials.Taylor MethodPay Back TimeSustainabilityThe environment is constantly changing, whether by nature or by human led processes. Sustainability is about trying to suffice this change through balancing social, economic and environmental needs, both locally and globally for present and future generations.HAZOPRisksThe production of ammonia involves working at commodious temperatures and pressures. As such, it is vital that the equipment used in the plant is designed to withstand these conditions to function properly. The high te mperatures and pressures involved in the production of ammonia can potentially put tremendous amounts of strain on the pipes and vessels used. The risks associated with this are * Explosions from sudden release of pressurised gases from ruptured vessels * Fragmentation from rupture of the pipes* fervency* Poisoning from exposure to leaked materials* Chemical or thermal burns, again from exposure to leaked materials Not only are these hazards life-threatening, they would also be very expensive to put right for the production company. These risks can be avoided by preparing the plant for the conditions that it is about to go through. It is more economically viable to run the steam reformer at as high a temperature and pressure as possible. Magnesium oxide-lined furnaces, MgO, has a melting point of around 2800 degrees Fahrenheit, making it ideal for lining the furnaces used in the production of hydrogen. Hydrogen itself will cause some materials to become brittle and eventually brea k. Hydrogen features an brisk electron and thus will behave like a halogen, causing erosion in the metals that it comes into advert with.This can be avoided by using high-purity chromium steel steel in the sections of the plant which will come into contact with the hydrogen. This steel must have a maximum hardness of 80 HRB on the Rockwell Scale. Ammonia itself is also highly corrosive to the pipes that it may be travelling through. For this reason, it is recommended that stainless steel is also used here, at a similar hardness of that shown above. nearly ammonia plants use centrifugally cast high-alloy tubing to hold the nickel-base catalyst in the primary reformer furnace. The most commonly used is similar in establishment to grade 310 with 25% chromium and 20% nickel, balance iron. This has a carbon content in the grasp of 0.35 0.45% for improved high-temperature creep and rupture stress. Thermal guard of piping involves fire brick owing to the high temperatures involved.