#!/usr/bin/env python
# coding: utf-8

# <!--NOTEBOOK_HEADER-->
# *This notebook contains course material from [CBE20255](https://jckantor.github.io/CBE20255)
# by Jeffrey Kantor (jeff at nd.edu); the content is available [on Github](https://github.com/jckantor/CBE20255.git).
# The text is released under the [CC-BY-NC-ND-4.0 license](https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode),
# and code is released under the [MIT license](https://opensource.org/licenses/MIT).*

# <!--NAVIGATION-->
# < [Reactors](http://nbviewer.jupyter.org/github/jckantor/CBE20255/blob/master/notebooks/05.00-Reactors.ipynb) | [Contents](toc.ipynb) | [Steam Reforming of Methane](http://nbviewer.jupyter.org/github/jckantor/CBE20255/blob/master/notebooks/05.02-Steam-Reforming-of-Methane.ipynb) ><p><a href="https://colab.research.google.com/github/jckantor/CBE20255/blob/master/notebooks/05.01-Dehydrogenation-of-Propane.ipynb"><img align="left" src="https://colab.research.google.com/assets/colab-badge.svg" alt="Open in Colab" title="Open in Google Colaboratory"></a>

# # Dehydrogenation of Propane
# 
# (Example 4.7-2 from Felder, et al.)
# 
# Propane can be dehydrogenated to form propylene in a catalytic reactor: 
# 
# $$C_3H_8 \longrightarrow C_3H_6 + H_2$$
# 
# A process is to be designed for a 95% overall conversion of propane. The reaction products are separated into two streams: the first, which contains H2, C3H6, and 0.555% of the propane that leaves the reactor, is taken off as product; the second stream, which contains the balance of the unreacted propane and propylene in an amount equal to 5% of that in the first stream, is recycled to the reactor. Calculate the composition of the product, the ratio (moles recycled)/(mole fresh feed), and the single-pass conversion.
# 
# 

# * [Example 4.7-2 Dehydrogenation of Propane](#scrollTo=QNHvXizqqcc6)
# * [Process Model](#scrollTo=XEn6os4dvqZX)
# * [Product Composition](#scrollTo=zIxh44zIvD_a)
# * [Recycle Ratio](#scrollTo=0z2mr1SVvG3P)
# * [Single Pass Conversion](#scrollTo=3XZtQmHcvWaY)
# * [How Does Process Performance Depend on Single Pass Conversion?](#scrollTo=VIrO99Kqvzkz)

# ## Process Model

# In[1]:


from sympy import *

# define constants

nfeed = 100.0

# define variables

var('X')
var('n1:11')

# define constants

# unit balances

mixer = [
    Eq(nfeed + n9, n1),     # C3H8
    Eq(n10, n2)             # C3H6
]

reactor = [
    Eq(n3, n1 - X),         # C3H8
    Eq(n4, n2 + X),         # C3H6
    Eq(n5, X)               # H2
]

separator = [
    Eq(n3, n6 + n9),        # C3H8
    Eq(n4, n7 + n10),       # C3H6
    Eq(n5, n8)              # H2
]

# process specifications

specs = [
    Eq(n6, (1-0.95)*nfeed), # 95% process conversion
    Eq(n6, 0.00555*n3),     # 0.555% of propane recovered in propylene product
    Eq(n10, 0.05*n7)        # propylene recycle is 5% of outlet flow
]

soln = solve(mixer + reactor + separator + specs)
soln


# ### Product Composition

# In[2]:


nTotal = soln[n6] + soln[n7] + soln[n8]
print('C3H8 Product = ', round(100*soln[n6]/nTotal,2), '%')
print('C3H6 Product = ', round(100*soln[n7]/nTotal,2), '%')
print('  H2 Product = ', round(100*soln[n8]/nTotal,2), '%')


# ### Recycle Ratio

# In[3]:


print('Recycle Ratio = ', (soln[n9] + soln[n10])/nfeed)


# ### Single Pass Conversion

# In[4]:


print('Single Pass Conversion', (soln[n1] - soln[n3])/soln[n1])


# In[ ]:





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# < [Reactors](http://nbviewer.jupyter.org/github/jckantor/CBE20255/blob/master/notebooks/05.00-Reactors.ipynb) | [Contents](toc.ipynb) | [Steam Reforming of Methane](http://nbviewer.jupyter.org/github/jckantor/CBE20255/blob/master/notebooks/05.02-Steam-Reforming-of-Methane.ipynb) ><p><a href="https://colab.research.google.com/github/jckantor/CBE20255/blob/master/notebooks/05.01-Dehydrogenation-of-Propane.ipynb"><img align="left" src="https://colab.research.google.com/assets/colab-badge.svg" alt="Open in Colab" title="Open in Google Colaboratory"></a>