#!/usr/bin/env python # coding: utf-8 # # *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).* # # < [Global CO₂ Budget](http://nbviewer.jupyter.org/github/jckantor/CBE20255/blob/master/notebooks/03.01-Global-CO2-Budget.ipynb) | [Contents](toc.ipynb) | [Separating Milk](http://nbviewer.jupyter.org/github/jckantor/CBE20255/blob/master/notebooks/03.04-Separating-Milk.ipynb) >

# # CO₂ Production by Automobiles # ## Summary # # This notebook demonstrates the solution of a mass balance for a vehicle powered by an internal combusion engine. # ## Examples # ### How much CO₂ is generated per mile driven with an ICE? # # A recent model automobile is advertised with a fuel consumption of 30 miles per gallon of gasoline. Assume gasoline consists of pure octane $C_8H_{18}$, has a specific gravity of 0.74, and is consumed via the chemical reaction # # $$C_8H_{18} + \frac{25}{2}\ O_2 \longrightarrow 8\ CO_2 + 9\ H_2O$$ # # How much $CO_2$ is generated per mile driven? Report your answer in grams/mile. # # **Solution** # In[1]: liters_per_m3 = 1000.0 gallons_per_m3 = 264.17 V_lpm = (1.0*liters_per_m3/gallons_per_m3)/30.0 # volume of gasline in liters/mile m_kg = 0.74*V_lpm # mass of gasoline in kg/mile m_grams = m_kg*1000.0 # mass of gasoline in grams/mile n_octane = m_grams/114.0 # moles of gasoline in gmol/mile n_co2 = 8.0*n_octane # modles of CO2 in gmol/mile m_co2 = 44.0*n_co2 # mass of CO2 in grams/mile print("Gasoline consumed per mile = ", round(m_grams,1), "g/mile") print("Gram moles of octane per mile = ", round(n_octane,3) ,"gmol/mile") print("CO2 Production =", round(m_co2,1), "g/mile") # ### How much CO₂ is generated per mile driven by an electric car? # # Owners of the Tesla S electric car report an average electricity consumption of 0.367 kilowatt-hours per mile driven. # # Assume the electricity is produced from natural gas which, [according to the U.S. Energy Information Administration](https://www.eia.gov/tools/faqs/faq.cfm?id=74&t=11), produces 117.0 pounds of $CO_2$ per million BTU consumed, and requires 10,400 BTU to produce a kilowatt-hour of electricity. Assume an overall transmission efficiency of 80% from the power plant to the Tesla motor. How many grams of $CO_2$ are generated per mile driven by the Tesla? # **Solution** # In[2]: grams_per_lb = 453.593 w_kwh = 0.367 # kwh per mile q_btu = (w_kwh/0.8)*10400.0 # natural gas per mile print("Thermal energy requirement =",round(q_btu,2),"BTU per mile driven") # In[3]: m_co2_lb = 117.0*q_btu/1.0e6 # mass CO2 lb/mile m_co2_grams = m_co2_lb*grams_per_lb # mass CO2 grams/mile print("CO2 Production =", round(m_co2_grams,2), "grams per mile") # # < [Global CO₂ Budget](http://nbviewer.jupyter.org/github/jckantor/CBE20255/blob/master/notebooks/03.01-Global-CO2-Budget.ipynb) | [Contents](toc.ipynb) | [Separating Milk](http://nbviewer.jupyter.org/github/jckantor/CBE20255/blob/master/notebooks/03.04-Separating-Milk.ipynb) >