Accounting for water formation from hydrocarbon fuel combustion in life cycle analyses

Abstract

Hydrocarbon fuel production and utilization are considered water intensive processes due to the high volumes of water used in source development and fuel processing. At the same time, there is significant water formed during combustion. However, this water is not currently widely harvested at the site of production. Instead, it is added to the hydrologic cycle, often in a different location from the fuel production site. This study quantifies the water formed from combustion of these fuels and analyzes the magnitudes of formation in the context of other hydrologic sources and sinks in order to facilitate future assessments of water harvesting technology and/or atmospheric impacts of combustion. Annual water formation from stoichiometric combustion of hydrocarbon fuels, including natural gas, oil-and natural gas liquid-derived products, and coal, in the United States and worldwide are presented and compared with quantities of water sequestered, evaporated, and stored in the atmosphere. Water production factors in terms of mass and energy of fuel consumed, WPFm and WPFe, respectively, are defined for the comparison of fuels and incorporation into future life cycle analyses (LCAs). Results show that water formation from combustion has increased worldwide from 2005 to 2015, with the largest increase coming from growth in combustion of natural gas. Water formation from combustion of hydrocarbon fuels equals or exceeds water sequestered from the hydrologic cycle through deep well injection in the US annually. Overall, water formation is deemed significant enough to warrant consideration by LCAs of water intensity in fuel production and use, and should be included in future analyses.

A regional assessment of the water embedded in the US electricity system

“…emissions, our results do not account for water consumption downstream of the power plant (e.g. for waste management past the power plant gate) or water production from combustion of hydrocarbons, which can be non-negligible volumes in some cases, though see [1,34] for further discussion. Results from this study should be interpreted carefully with this boundary in mind.…”

The CO2 Emissions Drivers of Post-Communist Economies in Eastern Europe and Central Asia

“…It produces carbon dioxide, CO 2 , water, and energy. For example, according to [1], "the total annual quantity of water formed from the combustion of hydrocarbon fuels exceeds the water sequestered from the hydrologic cycle through deep well injection in the US, but is substantially less than water volumes generated through evaporation and irrigation each year. However, this water is not currently widely harvested at the site of production.…”

“…Many scientists have empirically tested the impact of greenhouse gas (GHG) emissions on national economies as well as a proper relationship between various factors that cause those emissions. According to their findings, economic growth [1][2][3][4][5][6][7][8][9][10][11], energy prices [4,[12][13][14][15][16], electricity consumption [2,3,8,9,11,[17][18][19][20] energy efficiency [11,[21][22][23], institutional reforms and structural changes [16,[21][22][23][24][25][26][27], investment and trade openness [6,8,9,11,19,20,[28][29][30], and population dynamics and urbanization [2,…”

Sustaining Water Resources: Environmental and Economic Impact

“…In the US, hydrocarbon combustion produces 2.4 billion cubic meters of water per year, nearly twice the amount of water that is disposed of via deep well injection. 68 Integrating renewable energy with water infrastructure presents another opportunity for reducing the intensity of the water−energy nexus. The use of renewable wind and/or solar energy for electricity generation presents a 2-fold opportunity.…”

“…The water production from combustion is nontrivial, amounting to 12 billion cubic meters per year globally as of 2015. In the US, hydrocarbon combustion produces 2.4 billion cubic meters of water per year, nearly twice the amount of water that is disposed of via deep well injection …”