Lactic acid and biomethane production from bread waste: a techno-economic and profitability analysis using pinch technology

Maity, Sunil Kumar (2023) Lactic acid and biomethane production from bread waste: a techno-economic and profitability analysis using pinch technology. Sustainable Energy & Fuels, 7 (13). pp. 3034-3046. ISSN 2398-4902

Text
d3se00119a.pdf - Published Version
Download (2MB)

Abstract

Lactic acid (LA) is a vital platform chemical with diverse applications, especially for biodegradable polylactic acid. Bread waste (BW) is sugar-rich waste biomass generated in large quantities in residential and commercial operations. Recently, we evaluated the potential of BW for LA production by Bacillus coagulans under non-sterile conditions. This work presents a techno-economic and profitability analysis for valorizing 100 metric tons of BW per day to alleviate environmental pollution with concurrent production of LA and biomethane. We compared two fermentation approaches: acid-neutral (Scenario I) and low pH (Scenario II). Traditional esterification with methanol, followed by hydrolysis of methyl lactate, was employed for downstream separation to obtain polymer-grade LA. High-pressure steam was generated from solid debris via anaerobic digestion to complement energy demands partly. Energy consumption was further attenuated by process integration using pinch technology, with around 15% and 11% utility cost savings for Scenario I and II, respectively. These processes were capital-intensive, with 42-46% of LA production cost stemming from direct and indirect costs. Utilities were the major cost-contributing factor (19-21%) due to energy-intensive water evaporation from dilute fermentation broth. Due to additional processing steps, capital investment and operating costs were slightly higher in Scenario I than in Scenario II. LA manufacturing cost was thus more for Scenario I ($2.07 per kg) than Scenario II ($1.82 per kg). The minimum LA selling price for Scenario I and II were $3.52 and $3.22 per kg, respectively, with five-year payback periods and 8.5% internal rates of return. LA was slightly more expensive for decentralized BW processing than the market price.

[error in script]

IITH Creators:

IITH Creators	ORCiD
Maity, Sunil Kumar	https://orcid.org/0000-0002-1832-5060

Item Type:

Article

Uncontrolled Keywords:

Anaerobic digestion; Bacteriology; Economic analysis; Energy utilization; Fermentation; Food products; Investments; Operating costs; Profitability; Bacillus coagulans; Biomethane; Commercial operation; Diverse applications; Lactic acid production; Pinch technology; Platform chemicals; Profitability analysis; Techno-Economic analysis; Waste biomass; anaerobic digestion; biomass; capital flow; cost-benefit analysis; energy management; fermentation; food waste; hydrolysis; investment; production cost; Lactic acid

Subjects:

Chemical Engineering
Chemical Engineering > Food and Beverage technology
Chemical Engineering > Biochemical Engineering

Divisions:

Department of Chemical Engineering

Depositing User:

Mr Nigam Prasad Bisoyi

Date Deposited:

12 Nov 2023 09:35

Last Modified:

12 Nov 2023 09:35

URI:

http://raiithold.iith.ac.in/id/eprint/11740