|Cradle-to-Gate (farmer-to-product) pathways for soybeans. Source: USB. Click to enlarge.|
An updated life cycle assessment (LCA) of soybean production and products commissioned by the United Soybean Board found multiple energy and environmental benefits of current US soybean farming and processing. Currently, the data included in the Department of Energy’s US Life Cycle Inventory is based on three years, 1998 to 2001. This LCA project is based on US agricultural data for the 2001-2007 period. It also contains actual data on soybean processing, commonly known as crushing, that was not previously available.
A key objective was to update life cycle inventory (LCI) databases for soybean production and processing as well as conversion into four key soy-derived feedstocks (methyl soyate, soy lube base stock, soy polyol, and soy resin) used in fuel and industrial products. Its cradle-to-gate scope begins with soybean farming (the cradle) and goes through processing of products (the gate).
Omni Tech International, Ltd conducted the study for the United Soybean Board. Four Elements Consulting, LLC performed the life cycle assessment modeling. A group of international reviewers verified the project was performed in accordance with International Organization for Standardization (ISO) 14040/44 Life Cycle Requirements. Reviewers included Dr. Martin Patel of Utrecht University and Michael Levy of the American Chemistry Council.
Key findings of the study include:
Average soybean yield for the 2004-2007 time period was 42.35 bushels per acre, which represents a 12% increase over the data (1998-2000 average) used in the current US LCI database;
Each bushel of soybeans harvested reduces greenhouse gases (carbon dioxide (CO2) equivalents) by 32.6 kg (for the 3.36 billion bushels of soybeans produced in 2009 this would translate into the equivalent of taking 21 million cars off the road);
The calculated release of nitrous oxide (N2O), a potent greenhouse gas, is 85% less than the data contained in the current US LCI Database due to a corrected emission factor issued by the International Panel on Climate Change (IPCC) in 2006;
Approximately 20% less direct energy is used for soybean production due to reduced diesel and gasoline usage;r
Soybean crushing facilities reduced their energy consumption by 45% compared to the 1998 data;
Improved efficiencies at crushing facilities increased both soybean oil and meal yield compared to 1998 data, by 11% and 4% respectively; and
Hexane emissions at crushing facilities decreased over 70% compared to the 1998 data (going from 10.15 kilograms per 1,000 kilograms of oil produced to 2.96 kilograms).
The study provides a resource for companies to update life cycle assessments on their specific products made using US soy.
The United Soybean Board’s study sheds even more light on why biodiesel is good for the environment. Biodiesel production and use recognizes and builds on this progress.
—National Biodiesel Board Director of Sustainability Don Scott
Biodiesel production facilities reduced their energy consumption by 27% compared to the 1998 data. Biodiesel has even more benefits when one calculates the emissions reductions when it is used to fuel a vehicle.
USB is made up of 68 farmer-directors who oversee the investments of the soybean checkoff on behalf of all US soybean farmers. Checkoff funds are invested in the areas of animal utilization, human utilization, industrial utilization, industry relations, market access and supply. As stipulated in the Soybean Promotion, Research and Consumer Information Act, USDA’s Agricultural Marketing Service has oversight responsibilities for USB and the soybean checkoff.