OPEM models Downstream Oil Product Transport and Oil and Gas End Use Emissions
OPEM estimates two emissions sources: the transport of petroleum products by shipping entities and the end use of all petroleum products by various consumers. The combustion of natural gas and petroleum products by consumers (Scope 3 emissions) is increasingly being considered in this sector’s climate impacts.
OPEM considers all associated oil and gas products that are consumed. Historically, petroleum end use centered only on transport fuels, including gasoline and diesel, and ignored or incompletely and inconsistently reported GHG emissions from petroleum co-products like petcoke, fuel oil, residual fuels, asphalt, and petrochemical feedstocks. OPEM v.3.0 includes these co-products, as well as gas and natural gas liquids that were produced along with each barrel of crude.
OPEM estimates emissions using combustion, transport, and process emissions factors reported by the U.S. Environmental Protection Agency for GHG inventories and Argonne National Laboratory’s GREET model. Note that the EPA assumes high fuel quality and near-complete fuel combustion in the calculation of published combustion emissions factors. Depending on the quality of the engine in which a fuel is burned, EPA emissions factors may result in a best-case (lowest emissions) estimate. The model also assumes some percentage of ethane is converted to ethylene for petrochemical use, and assumes a conversion process emissions intensity, but does not include emissions associated with further processing and use of the ethylene product, nor does it include other petrochemical processes.
Instructions:
There are two ways to install the OPEM package:
- download the source code and install in editable mode (best option for those who want to make changes to the code);
- download the .whl or .tar.gz file from the latest release and install with pip
INSTRUCTIONS FOR OPTION 1:
Clone this repo to your local machine:
git clone https://github.com/zacharyschmidt/opem.git
or
git clone git@github.com:zacharyschmidt/opem.git
Once you have a local copy of the repo, navigate to the same directory as the setup.py file and create a virtual environment:
python -m venv venv
Activate the virtual environment:
source venv/bin/activate
Then run the command below to install the package in 'editable' mode (make sure you are in the same directory as the setup.py file). Any changes you make to the source code will automatically update the locally installed package.
pip install -e .
INSTRUCTIONS FOR OPTION 2:
Click on 'Releases', located in the rightmost section of the repository page (beneath 'About').
Find the latest release and open the 'Assets' dropdown. Then download either the .whl or .tar.gz file.
Set up and activate a virtual environment:
python -m venv venv
source venv/bin/activate
Use pip to install OPEM from the downloaded file. For example, if you have a .whl file in your current working directory:
pip install opem-1.0.4a0-py3-none-any.whl
Once the installation is complete you can run opem from anywhere on your local machine with the terminal command 'opem' (make sure the virtual environment is activated).
opem will look for a file named 'opem_input.csv' in your current working directory. An example input file is included. You can make changes to the values in column E to provide user input (don't change any other columns). Blank cells in column E will be ignored.
If it can find 'opem_input.csv' the program will run and write results to a new file 'opem_output.csv', saved to your current working directory.
The input and output files are based on the 'OPEM 3.0 Input Outputs' excel workbook created by Raghav Muralidharan (included in this repo). Please refer to this workbook to see how the names in the input/output csv filed map to parameters in the OPEM3.0 workbook.
HTML documentation can be found in the "documentation" folder (start at "index.html"). The opem_dev_usage_demo.py file shows how the opem library can be imported and used in scripts.