Environmental assessment of alternative pasteurization technologies for fluid milk production using process simulation

Authors: Tomasula, Peggy; Bonnaillie, Laetitia; Yee, Winnie

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/4/2015
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: JUSTIFICATION Fluid milk processing (FMP) has significant environmental impact because of its high energy use and greenhouse gas (GHG) emissions. High temperature short time (HTST) pasteurization is the third most energy intense operation in FMP comprising about 16% of total energy use, after clean-in-place operations and packaging. Thermal or nonthermal pasteurization processes for production of shelf – stable or extended shelf-life milk need to be explored as approaches to reduce energy use and GHG emissions in FMP. OBJECTIVE To develop models for alternative pasteurization methods to be used in a FM computer simulator to estimate their impact on energy use and greenhouse gas emissions in FMP. Only alternative processes that are currently amenable to continuous processing were selected. METHODOLOGY Models were developed for pulsed electric fields (PEF), microfiltration (MF), and ultrahigh temperature (UHT) processing. The simulator was built using SuperPro Designer (Intelligen, Inc., Scotch Plains, NJ). A plant producing 113.6 million L/yr of whole milk and 40% cream and extending from storage of raw milk to cold storage of processed milk, if applicable, was simulated. RESULTS/DISCUSSION Results indicated that GHG emissions, reported as carbon footprint of milk, were lowest at 37.6 g CO2 equivalents (e)/kg raw milk processed (RMP) for the HTST pasteurization base-case FMP. The carbon footprint of PEF as a pasteurization step was the highest of the alternative pasteurization methods at 99.1 g CO2 e/kg RMP. Specific energy consumptions (SEC) for HTST milk were 0.14 MJ/kg RMP for electrical use and 0.13 MJ/kg RMP for natural gas use while SEC using PEF were 0.44 MJ/kg RMP and 0.10 MJ/kg RMP, respectively. Energy use for PEF pasteurization was 51.7% of the total energy used for FMP. Other scenarios using PEF in the FMP simulator should reduce the attendant GHG emissions and SEC and will be explored. Operating costs associated with the PEF process were $0.52/L, $0.51/L for the HTST process, and $0.60/L for the UHT process. CONCLUSION The benchmarking capabilities of the FMP simulator allow determination of performance of alternative technologies without costly pilot plant trials and are a useful tool to identify process scenarios to improve the environmental impact of FMP.