Simulation-Based Estimates of Life Cycle Inventory Gate-to-Gate Process Energy Use for 151 Organic Chemical Syntheses

Abstract

Process energy data is integral to the sustainability analysis of chemical products and processes. However, due to the lack of primary data from chemical plants, process energy calculations in chemical life-cycle inventories (LCIs) often rely primarily on empirical averages, estimations based on proxy processes, or the industrial chemistry literature. In this study, we demonstrate a streamlined process simulation-based methodology to estimate energy consumption in chemical manufacturing when the data availability for the process is limited. The methodology is applied to 151 different chemical processes using Aspen Plus to estimate their gate-to-gate process energy use, representing the largest such simulation-based LCI data set to date. Further, pinch analysis used for process heat integration and specification of different utility types for each of the chemical processes enhance the representativeness of the LCI data. The total heating requirement for chemicals assessed ranges from 0.1 to 24 MJ/kg with an average of 3.1 MJ/kg product, while the average cooling requirement before heat integration is 4.5 MJ/kg. More than half of the total energy requirement comes from the separation section. Steam is the most used hot utility in the chemical industry which reflects in the simulation results, accounting for 70% of the heating requirements, while air and cooling water accounts for 40% of the cold utilities used. The engineering design-based estimates reported here represent a substantial addition to chemical LCI data and can provide a strong foundation for future predictive models for the large chemical universe.

Zero-Emission Pathway for the Global Chemical and Petrochemical Sector

“…New technology options and cross-cutting technologies such as advanced membranes to reduce process heat demand by 2050 [47] would double the improvements to 1%/yr. 2 While pinch analysis for heat integration shows 50% and 30% savings for hot and cold utilities, respectively [48], actual potential could still be lower, since efficiency is typically assessed at site level where a high level of steam system integration reduces potential. Renewable-hydrogen for ammonia (11,20) Feedstock switching Renewable hydrogen can replace fossil fuels used as feedstock for ammonia production [22].…”

Comparison between Different Hybrid Life Cycle Assessment Methodologies: A Review and Case Study of Biomass-based p-Xylene Production

“…Even the most comprehensive process background database currently only covers a small fraction of all chemicals sold on the market. 43 In the chemical process design, it is not uncommon to face the data gap of chemicals. The most common method in process LCA to fill the data gap is to use the stoichiometric ratio of raw materials.…”

“…It is especially the case for chemical production. Even the most comprehensive process background database currently only covers a small fraction of all chemicals sold on the market . In the chemical process design, it is not uncommon to face the data gap of chemicals.…”

“…42 Second, not all chemicals are covered in the database; only a fraction of more than 80 000 chemicals sold in the United States are in the commercial database. 43 Among the data captured, only a few necessary chemicals use the primary data directly obtained from chemical plants. Most chemical production processes are kept confidential.…”

“…The error differs from case to case and is mainly due to difficulties in tracking infinite supply chains and collecting data . Second, not all chemicals are covered in the database; only a fraction of more than 80 000 chemicals sold in the United States are in the commercial database . Among the data captured, only a few necessary chemicals use the primary data directly obtained from chemical plants.…”