The phrase near-zero emissions, which is also referred to as partial-zero emissions, is an all-encompassing term that describes technologies that reduce the environmental impact of engines. These technological advances reduce the emissions of particles and greenhouse gases that produce smog and acid rain, both of which lead to debilitating health issues and environmental concerns. Near-zero emission technologies are currently supported by the tightening EPA standards that apply to a variety of engines, including generators and vehicles.
What is Clean Diesel?
Efforts to reduce emissions from diesel engines are currently three-pronged.
- The latest generators and other diesel engines use ultra-low sulfur diesel (ULSD). There is 97% less sulfur than in low-sulfur diesel, which leads to a cleaner-burning fuel. There are downsides to this technology. The additional refining of the diesel fuel results in costs about 10% higher. This fuel is not available worldwide, including in some key regions.
- Diesel engine technology is becoming more efficient. Today’s engines are able to generate more power with less fuel. These innovations include “rail fuel injection, variable injection timing and improved combustion chamber configuration.”
- Emissions, including fine particulates and nitrogen oxide, are reduced with re-circulation technology and filters.
Renewable diesel fuel, or biodiesel, is a diesel-like fuel made from renewable materials. Instead of petroleum, biodiesel is made from organic oils, including rapeseed, soybean and vegetable oil. Biodiesel emissions have fewer fine particulates, nitrogen oxides, hydrocarbons and carbon monoxide than traditional diesel.
Other fuels are also undergoing changes to be less harmful to the environment and reduce reliance on finite fossil fuel resources. Biopropane is produced from waste, residue, vegetable oil and other renewable raw materials. Renewable natural gas “is an ultra-clean and ultra-low-carbon natural gas alternative made from the methane that is captured when waste from food scraps, animal manure, sewage and other organic sources is broken down, captured and refined.”