Title: Pretreatment of Biomass by Selected Type-III Deep Eutectic Solvents and Evaluation of the Pretreatment Effects on Hydrothermal Carbonization

Abstract

Hydrothermal carbonization (HTC) is a novel thermochemical conversion that converts wet biomass into energy dense solid fuel. Residual moisture under subcritical conditions reacts with a lignin-cellulose-hemicellulose matrix with the major reactions being identified as dehydration and decarboxylation. Among other reaction parameters (e.g., temperature, time, pressure), biomass morphology often plays a key role in HTC. The hypothesis of this study was enhancing the porous structure of biomass without significantly affecting biopolymer composition would augment hydrothermal carbonization (HTC). To prove the hypothesis, two type-III deep eutectic solvents (DESs), namely choline chloride:urea (ChCl:Urea, 1:2 mol/mol) and methyltriphenylphosphonium bromide:ethylene glycol (MTPB:EG, 1:4 mol/mol), were studied to pretreat loblolly pine at room temperature and ambient pressure for 1 h. DES pretreatment shows swelling of the biomass, increasing the surface fiber-to-fiber gap length by 52% and 185% for ChCl:Urea and MPTB:EG pretreatments, respectively. The total pore volume remained intact (2.6 × 10^–3 cm³/g), although new small pores evolved, and existing pores were abated with DES pretreatment. Hydrochars prepared from DES pretreated loblolly pine showed a high O/C and H/C ratio resulting in a significant increase of energy content (up to 42%) and a decrease of mass yield (up to 50 wt %), indicating an enhancement ofmore » HTC severity due to the alteration of surface morphology by DES. Finally, a preliminary process economics revealed that integrated DES pretreatment-HTC would increase fixed capital investment but decrease the cost of operation and manufacturing than the standalone HTC process.« less

Authors:

Islam, Md Tahmid ^[1]; Sultana, Al Ibtida  ^[1];

• Search DOE PAGES for author "Sultana, Al Ibtida"
• Search DOE PAGES for ORCID "0000-0002-4411-4355"

Saha, Nepu ^[2]; Klinger, Jordan L.  ^[2];

• Search DOE PAGES for author "Klinger, Jordan L."
• Search DOE PAGES for ORCID "0000-0003-4004-9864"

Reza, M. Toufiq  ^[1]

• Search DOE PAGES for author "Reza, M. Toufiq"
• Search DOE PAGES for ORCID "0000-0001-9856-5947"

---

+ Show Author Affiliations

1. Florida Institute of Technology, Melbourne, FL (United States)
2. Idaho National Lab. (INL), Idaho Falls, ID (United States)

Publication Date:

Thu Oct 21 00:00:00 EDT 2021

Research Org.:

Idaho National Laboratory (INL), Idaho Falls, ID (United States)

Sponsoring Org.:

USDOE Office of Energy Efficiency and Renewable Energy (EERE), Transportation Office. Bioenergy Technologies Office; National Science Foundation (NSF); USDA

OSTI Identifier:

1903512

Report Number(s):

INL/JOU-21-63600-Rev000
Journal ID: ISSN 0888-5885; TRN: US2311347

Grant/Contract Number:  

AC07-05ID14517; 1856058; 2019-67019-31594

Resource Type:

Accepted Manuscript

Journal Name:

Industrial and Engineering Chemistry Research

Additional Journal Information:

Journal Volume: 60; Journal Issue: 43; Journal ID: ISSN 0888-5885

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

09 BIOMASS FUELS; biomass; deep eutectic solvent; swelling; hydrothermal carbonization; process economics; biopolymers; organic polymers; pretreatment; separation science