Refrigeration Cycle

Example:

A Refrigeration cycle utilizes propane as the working fluid is used in

the liquefaction of the NG. Propane is fed to an evaporator (Heater) the pressure drop-5 kPa, where it absorbed 1.50e+6 kJ/hr from the NG and leaves at the dew point (Vapor Fraction=1.0) at T= -15°C. The output of the evaporator is then compressed adiabatically with efficiency of 75%, and then it's condensed to reject heat. Inside the Condenser there is a pressure drop of 30 kPa, and leaves as saturated liquid at 45°C. Finally, the propane passes through a valve to return the pressure of the Evaporator.

Fluid Pkg: Peng Robinson

 

Plug Flow Reactor

PROBLEM STATEMENT

Consider the reversible aqueous phase esterification

of acetic acid shown below:

CH3COOH + C2H5OH = CH3COOC2H5 + H₂O

Reaction Kinetics:

Forward Reaction: 8 x 10-6m³ kmol-1s-1

Backward Reaction: 2.6 x 10-6m³ kmol-1s-1

Activate.

It is desired to produce 375kg/hr of ethyl acetate from a

feed stream consisting of 13mole% acetic acid, 35mole%

ethanol and 52mole% water. This feed stream is available

at 100,000kg/day. A single tube plug flow reactor with a

length of 10m and diameter of 1m is available for use in

an existing chemical plant. Determine if it is feasible to

achieve the desired product using this reactor, also find

the residence time in minutes.

Fluid Package: NRTL.

Feed Properties: 25°C, 1Bar.

 

Plate Heat Exchanger

Introduction.

• To simulate a plate heat exchanger using the

simple end point model.

• To simulate a plate heat exchanger using the

rigorous model.

Transferring rigorous data to the simple end point

model.

 

PROCESS INVOLVING RECYCLE

PROCESS INVOLVING RECYCLE

Ethyl chloride will be produced by the gas-phase reaction of HCI with ethylene over a copper  chloride catalyst supported on silica as

C2H4+HCI→C2H5CI

The feed stream is composed of 50 mol% HCl, 48 mol% C₂H, and 2 mol% N₂ at 100  kmol/hr, 25 °C, and 1 atm. Since the reaction achieves only 90 mol% conversion, the ethyl  chloride product is separated from the unreacted reactants, and the latter is recycled. The

Separation is achieved using a distillation column, where it is assumed that a perfect  separation is achievable. The process is operated at atmospheric pressure, and pressure drops

are ignored.

 To prevent the accumulation of inerts in the system, 10 kmol/hr is withdrawn in a purge stream. W. Show the effect of the flowrate of the purge stream W on the recycle R and on the composition of the reactor feed.

 

Optimization on Hysys

INTRODUCTION

• In this lecture, a simple distillation column to separate

Tetrahydrofuran (THF) from Toluene is simulated. The

objective of the exercise is to select the product

specifications such that profit is maximized.

A special tool in HYSYS, the Optimizer, will be used to

find the optimum operating conditions.

HYSYS includes additional modelling and decision

support tools that can be used to enhance the usability

of your models.

In this lecture, you will use the HYSYS optimization too

available in HYSYS to investigate the debottlenecking

and optimization of a crude column.

LEARNING OUTCOMES

• Use the Optimizer tool in HYSYS to optimize flowsheets

• Use the Spreadsheet to perform calculations

 PROBLEM STATEMENT

⚫ 3700 kg/hr mixture of tetrahydrofuran & toluene

(44 mass% THF) at 10°C and 140 kPa is to be

separated by distillation to get each of them with

purity of 99.5 mass% of THF & 94 mass% of

Toluene (THF is the more volatile component).

• Use Wilson fluid package

PROBLEM STATEMENT CONT.

The column specifications are:

The condenser & reboiler pressure are 103 kPa & 107

kPa.

The condenser works on total condensation

conditions.

Number of stages = 10.

• Feed enters from the 5th tray.

• Calculate:

- The reflux ratio and the distillate rate under the

specified conditions.

Separation Columns De ethanizer and De Propanizer modelled as Distillation.

Hysys can model   wide range of different column configurations. In this simulation, that will span for to lectures , the NGL will be built, consisting of three columns: 

- De methanizer (operate and peeled hair removal column absorption). 

- De ethanizer (Distillation Column).

- De-proporanizer (distillation column).

PROBLEM STATEME

A pump is used to move the De-Methanizer bottom

product to the 6th stage of the De-Ethanizer(modelled as

a 16-stage-Distillation Column), 14 trays in the column,

plus the reboiler and condenser. It operates at 400 psia.

The objective of this column is to produce a bottom

product that has a ratio of ethane to propane of 0.01.

• Using the given data, simulate the above process.

• What is the flowrate of C, and C, in the De-Ethanizer

bottom product and the ratio of C2/C3

• What is the Overhead Vapour rate when C2/C3 is 0.01

simulation

 

Shell & Tube Heat Exchanger Design

How does the heat exchanger is work in the HYSYS program?, we have already talked about that, but we will explain more in this video simulation design heat exchanger.

 

 In this paper simulation of some process equipments were done by HYSYS , Equipment simulation is a basic work to design a chemical process plant. HYSYS is an easy and leading powerful process engineering simulation tool. Study shows the major advantages of the process simulator HYSYS over other simulation softwares and the causes of it’s preference. The equipments were chosen from typical downstream oil and gas process plants. This study involves the simulation of equipments such as heat exchangers, separators, vessels, distillation column, pumps, compressors, heaters and absorption tower

simulation

 

Pressure Drop Pipeline

Pressure drop (often abbreviated as "dP" or "ΔP") is defined as the difference in total pressure between two points of a fluid carrying network. A pressure drop occurs when frictional forces, caused by the resistance to flow, act on a fluid as it flows through a conduit (such as a channel, pipe, or tube). This friction converts some of the fluid’s hydraulic energy to thermal energy (i.e., internal energy). Since the thermal energy cannot be converted back to hydraulic energy, the fluid experiences a drop in pressure, 

.as is required by conservation of energy

The main determinants of resistance to fluid flow are fluid velocity through the pipe and fluid viscosity. Pressure drop increases proportionally to the frictional shear forces within the piping network. A piping network containing a high relative roughness rating as well as many pipe fittings and joints, tube convergence, divergence, turns, surface roughness, and other physical properties will affect the pressure drop. High flow velocities or high fluid viscosities result in a larger pressure drop across a pipe section, valve, or elbow joint. Low velocity will result in less (or no) pressure drop. The fluid may also be biphasic as in pneumatic conveying with a gas and a solid; in this case, the friction of the solid must also be taken into consideration for calculating the pressure drop.

 

De Methanizer

Introduction to the contractor 

Hysys can model   wide range of different column configurations. In this simulation, that will span for to lectures , the NGL will be built, consisting of three columns: 

- De methanizer (operate and peeled hair removal column absorption). 

- Deethanizer (Distillation Column).

- De-proporanizer (distillation column).

Learning Outcomes

• Add columns using input experts.

 • Add additional specifications to columns.

Presentation of the problem acc

- simulated a demethanizer (similar to a 10-stage reboiler adsorption process) with two natural gas feed streams of a 2.1 × 106 kJ/h energy feed stream, which is a bypass heater on the shaft.  

-The first feed enters at the top of the shaft, the second feed enters the second stage and the power is fed into the fourth stage. 

 -What is the molecular fraction of methane in the top product.

feed 1&2

simulation