National and State-Level Energy Consumption and Cost Analysis of Drying Processes in the U.S. Chemical Industry

Abstract

Thermal drying is among the most energy-intensive unit operations in chemical manufacturing, yet its contribution to energy use across the U.S. chemical sector has not been quantified at the unit-operation level. This study presents a national techno-economic assessment of thermal drying and molecular-sieve across the U.S. chemical sector. A thermodynamic model based on the minimum theoretical energy for moisture removal and dryer-specific efficiencies was combined with national production data, product-level moisture, and state-resolved fuel prices to estimate annual drying energy demand and cost. Specific energy consumption (SEC) was calculated for 73 products, of which 45, those with production data available in the literature, were carried forward to the total energy and cost analysis, including products that are major energy consumers in the U.S. The calculated SEC values agreed well with published data. Thermal drying is estimated to consume approximately 166 TBtu/yr (range 161–172 TBtu/yr), corresponding to about 4.2% of total U.S. chemical-sector energy use and 20.8% of its process-heating demand. At the subsector level, other basic inorganic chemicals, ethyl alcohol manufacturing, and other basic organic chemicals are the largest consumers, with precipitated calcium carbonate (PCC) and ethanol alone accounting for 31% and 18% of total drying energy, respectively. The associated energy cost is approximately $1,610 million in 2024, with California, Iowa, and Minnesota as the principal contributors owing to facility density and regional energy prices. Conventional efficiency measures and advanced technologies are reviewed as OPEX cost-reduction pathways. The results provide a quantitative baseline to prioritize energy-efficiency interventions in chemical-sector drying.