Under The Guidance OF Mrs.N.SudhaRani By B. Rajasekhar Ch.Madhubabu M. Ramya N.Ganesh varma Department of chemical engineering:BEC

 Project statement  Introduction of the product  History of the product  Properties  Applications  Advantages over other oxygenates  Literature survey: comparison and selection of processes  Flow sheet  Material balances  references

 The purpose of this project is to determine the feasibility of constructing a chemical plant to manufacture 1,00,000 ton/y of MTBE by liquid phase catalysis of methanol and isobutylene using sulfuric acid catalyst.  Both methanol and isobutylene are pure and available from natural gas and refinery cuts respectively.  This project includes Simulation of flowsheet using chemcad- Simulation of PFR using MATLAB (or) spreadsheet. Specific equipment design for Heatexchanger Preliminary cost estimation and Plant design &layout.

 MTBE(methyl tertiary butyl ether) belongs to oxygenates family eg: ethers, alcohols.  It is a gasoline additive that boosts the oxygen content of gasoline which is also called as “an octane enhancer”.  Results in significant reduction in air pollution from vehicle exhausts as it replaces TEL and TML.  Can be used in concentrations on average of 8-10 weight % in gasoline.

 MTBE production started and shooted up between in US since the phase out of ‘lead’ in1970.  US EPA ordered to stop its production in 1999 due to ground water contamination and to replace with ethanol.  But EU of MTBE,Europe studies concluded that It does not pose danger to human health but tight controls are required on handling and storage. US EPA studies might be faulty.  In Europe production approximately equals the demand and firmly stable in next few years.  8 Asian countries like Japan, China etc already phased out lead and started MTBE production. INDIA is in progress

 Chemical Name: 2-methoxy-2- methyl-propane (IUPAC)  Chemical Family: Alkyl ethers  Form: At room temperature it is a highly volatile, flammable and colorless liquid.  Common Names: MTBE Methyl tert-butyl ether tert-Butyl methyl ether  CAS# :  Formula: C 5 H 12 O  Chemical Structure:

 Molecular weight :  Elemental analysis Carbon content, wt% : 68.1 Hydrogen content, wt% :13.7 Oxygen content, wt% :18.2  C/H ratio :5.0  Density, g/cc at 25° : at 30°C :  Reid vapor pressure at 25°C, psi- : 7.8  Boiling point, °C :55.0  Freezing point, °C :  Critical properties: temperature(Tc),°K: : 510 pressure (Pc),Pa :3.31*e5 volume(Vc),m3\kmol :0.329

 Solubility of MTBE in water at 25°C, wt%: :<5  Viscosity at 37.8°C, cSt :11.7  Refractive index at 20°C :  Surface tension, din/sqrcm :19.4  Latent heat of vaporization at 25°C, Cal/g :81.7  Specific heat at 25°C, Cal/g°C :0.51  Flammability limits in air Lower limit, vol% :1.5 Upper limit, vol% :8.5  Auto ignition temperature, °C :425  Flash point, °C : -30  Blending octane number RON :117 MON :101 (RON+MON)/2 :110

 90% of total production of MTBE is used as an antiknocking agent. Remaining 10%  To produce highly reactive polyisobutylene, butylrubber, methylmethacrylate.  As a solvent replaced with diethyl ethers to improve the miscibility of other solvents.  In clinical medicine to dissolve the cholesterol gall stones.

 Other oxygenates are Ethers: TAME,TAEE,ETBE, Alcohols: ethanol, methanol.  Ethers have comparatively: low RVP low vaporization temperature low flame temperature and high octane number.  Among ethers MTBE is proven to be economically effective as its physical, chemical properties are compatible with gasoline especially its boiling range.  Higher octane number than other ethers.

 There are three types of MTBE production plants:  Refinery/Petrochemical plants: uses Isobutylene, produced as a byproduct in refinery catalytic crackers.  Merchant plants: Merchant plants uses normal butane to isobutane, dehydrogenate isobutane to isobutylene  TBA plants: TBA plants uses tertiary butyl alcohol (TBA) as a byproduct of the propylene oxide production process.  Another raw material is methanol for all plants

Type of plantProduction cost per daily barrel of capacity Yield of MTBEconclusions Refinery chemical plants $6,000 - $10, %Smallest and least expensive Merchant plants $20,000- $28, %Large area and highly expensive TBA plantsLess than $15,000 98%Only two plants are available out of the world as availability of TBA is low.

 Refinery plants are proven to be least expensive which can also work on less purity raw materials.  Operated in only liquid phase with either solid or liquid phase acid catalysts.  Solid phase catalysed process Liquid phase catalysed process Acidified ion exchange catalysts eg: zeolites, amberlyst etc. Available at low cost Main disadvantage is regeneration cost is too high. Acids such as H 2 SO 4, HCL etc. Also available at low cost Catalyst can be recovered as pure can be reused.

 Basis :100,000 ton/y of MTBE with on-stream factor of 0.9.  Reactants mole ratio (CH 3 OH to C 4 H 8 ):- 1.1  Product in kmol/h : 100,000*1000/(328*24*88.15)=144.1  Feed requirements to produce 144.1kmol/h of mtbe:  C 4 H 8 == kmol/h (144.1/0.895)  CH 3 OH == kmol/h (1.1*162.46)  Sulfuric acid== 7.57 kmol/h (5wt% of reaction mixture)  Molecular weights(kg/kmol): C 4 H 8: 56.1 CH 3 OH:32.04 Sulfuric acid:98 MTBE:88.15

 Reactor  Separator 1  Washer  Separator 2  Distillation column 1  Distillation column 2  Mixers-1,2,3

Conversion= 89.5% 1 mole of isobutene requires 1mole of methanol to produce 1mole of product(from reaction stoichiometry) Mole flow inlet (kmol/hr) Mass flow inlet (kg/hr) Mole flow out (kmol/hr) Mass flow Out (kg/hr) Methanol Isobutene Sulfuric acid MTBE water Total

Total mass flow rate in = kg/h Total mass flow rate out= = kg/hr IN RATE = OUT RATE Sulfuric acid recovery= 97% and methanol=2% from bottom Top and washer inlet(kg/hr) Bottom and mixer 3 inlet Methanol Iso-butylene sulfuricacid MTBE water Total mass rate

Total mass flow rate in= seperator1 top+ fresh water in= = = kg/hr Total mass rate out= kg/hr ComponentsWasher outlet and Seperator 2 inlet(kg/hr) methanol Iso-butylene Sulfuric acid water mtbe total

 99.8% of MTBE 100% of isobutene is removed from the top. Water and methanol from the bottom.  Total mass in = kg/hr  Total mass out = = kg/hr Sep 2 top and distillation 1 feed(kg/hr) Sep 2 bottom and distillation 2 Feed(kg/hr) methanol Isobutylene Sulfuric acid MTBE Water total

 Distillate purity xd = 91.05%  bottom product purity: 99.97%  Total feed= kg/hr outlet=D+B= kg/hr Feed (kg/hr) Feed mole fraction Distil late( D) (kg/h r) Distilla te mole frac Residue (B) Kg/hr Residue mole frac Iso butene Methanol e-6 MTBE Total

 Total feed (SEP 2 bottoms),F = kg/hr  Dstillate purity.x d= ,  Feed F = kg/hr =(D+B)= ( )kg/hr Feed (kg/hr) (F) Feed mole frac Distillate (kg/hr) (D) Distillate Mol frac Resdue (kg/hr) (B) Residue Mole frac Methanol Water Sulfuric acid MTBE TOTAL

 Mixer 1:  Inlet streams: fresh methanol + recycle stream from distillation column 2: = kg/hr  Outlet stream flow rate = kg/hr.  Mixer 2:  Inlet streams= mixer1 outlet +fresh isobutene+ recycle stream from distillation column 1: = = kg/hr  Outlet flow rate = kg/hr  Mixer 3: inlet streams = mixer 2 outlet + fresh sulfuric acid + recycle stream from seperator 1 = = kg/hr Outlet mass flow rate = kg/hr.

History,properties, applications: Hand book of MTBE by “Hamid and Ali” Literature survey; wikipedia.org Hand book of MTBE by “Hamid and Ali” Chemical reaction kinetics: “kinetics of MTBEcatalyzed by sulfuric acid ” an article By ADNANM.AL JARALLAH and A.K.K LEE. Mass balances: “chemical process principles” standard text books process flow sheet and description: “Economics of the new MTBE design ” an article By ADNANM.AL JARALLAH

 Energy balances  Simulation of PFR  Specific equipment design  Plant location and layout  Health and safety factors  Preliminary cost estimation etc