Benzoic acid

The dewatered DSS feedstock used in this study was provided by Bergen Water and their biogas facility in Norway. The DSS was used as received with no drying or homogenisation, hence there is a risk of a certain degree of inhomogeneity in the batches used for each experiment.
Ethyl acetate (EtOAc, > 99.5%), ethanol (absolute, 99.96%), formic acid (> 98%), sodium sulphate ( $\ge$  99.0%, anhydrous), dodecane (analytical standard), benzoic acid ( $\ge$  99.5%), pyridine ( $\ge$  99.5%), N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) w/1% trimethylchlorosilane (TMCS)) and pentane ( $\ge$  99%) were purchased from Merck (Saint-Louis, MO, USA) and used without further purification.
The oil yields are calculated by mass of oil produced relative to input mass of dry, organic feedstock. The energy recovery in the bio-oil is calculated relative to the organic matter input in the DSS. As formic acid does not contribute significantly to the oil yield^{31 (link)}, this input is not included in the yield calculations. When ethanol is included in the reaction medium, it can react with specific hydroxyl substituents^{32 (link)} or in esterification of carboxylic acids. However, such contributions were not included in the yield calculations due to challenges in quantification, and this gives an unknown uncertainty in the recovery values for the different systems.

2,3,4,5,6-D₅-benzoic acid (internal standard, ≥99 atom % D, ≥99%), benzoic acid (BA, ≥99.5%), phenylpropionic acid (PhPA, ≥99%), phenyllactic acid (PhLA, ≥98%), 4-hydroxyphenylacetic acid (p-HPhAA, ≥98%), 4-hydroxyphenyllactic acid (p-HPhLA, ≥97%), 3,4-dihydroxybenzoic acid (internal standard, ≥98%), succinic acid (≥99%), α-ketoglutaric acid (≥98%), fumaric acid (≥99%), itaconic acid (≥99%), N,O-bis(trimethylsilyl)trifluoroacetamide (contains 1% trimethylchlorosilane, 99% N,O-bis(trimethylsilyl)trifluoroacetamide), hexane (≥97.0%) were obtained from Merck (Darmstadt, Germany); sulfuric acid, acetone, diethyl ether, sodium chloride were Laboratory Reagent grade and obtained from Khimreactiv (Staryy Oskol, Russia). All other reagents were from the Sigma–Aldrich Corporation (St. Louis, MO, USA).

Benzoic acid (BA, ≥99.5%), phenyllactic acid (PLA, ≥98%) and 4-hydroxyphenyllactic acid (HPLA, ≥97%) were obtained from Merck (Darmstadt, Germany); all other reagents were from the Sigma–Aldrich Corporation (St. Louis, MO, USA).

All of the chemicals were of analytical grade. Methanol, phosphoric acid, vanillin, cyanidin, and benzoic acid were purchased from Merck (Darmstadt, Germany). Quercetin, rescorcinol, and luteolin were acquired from Sigma Chemical Co. (St. Louis, MO, USA). High performance liquid chromatography (HPLC-DAD) was performed with a Shimadzu Prominence Auto Sampler (SIL-20A) HPLC system (Shimadzu, Kyoto, Japan), equipped with Shimadzu LC-20AT reciprocating pumps connected to a DGU 20A5 degasser with a CBM 20A integrator, SPD-M20A diode array detector, and LC solution 1.22 SP1 software.

The lovastatin (LOV) raw material was purchased from Valdequimica, Brazil (purity reported to be >99%) and used without further purification. Adipic acid (ADI, 99% purity), citric acid (CIT, 99% purity), and tartaric acid (TAR, 99% purity) were acquired from Fischer Scientific (Hampton, NH, USA). Benzoic acid (BEN, 99% purity), salicylic acid (SAL, 99% purity) and cinnamic acid (CIN, 99% purity) were purchased from Merck (Darmstadt, Hesse, Germany), Mallinckrodt (Phillipsburg, NY, USA) and Sigma-Aldrich (Saint Louis, MO, USA), respectively. Lovastatin pharmaceutical secondary standard traceable to USP and PhEur Fluka brand used in the HPLC quantification studies was purchased from Sigma-Aldrich. All solvents were HPLC/UV grade, and water was purified using a Millipore system filtered through a Millipore 0.22 µm Millipak™ 40 membrane.

Ag(I) carboxylates (Ag(I) 2,2-dimethylbutanoate, Ag(I) benzoate, Ag(I) 2,2-dimethylbutanoate-d₁₁, Ag(I) 2-methylpentanoate, Ag(I) hexanoate, and Ag(I) heptanoate) were synthesised from the corresponding carboxylic acids (2,2-dimethylbutanoic acid (Alfa Aesar, Haverhill, MA, USA, 97%)), benzoic acid (Merck, Darmstadt, Germany, 99%), 2,2-dimethylbutanoic acid d₁₁ (CDN Isotopes, QC, Canada, 98.4% d₁₁), 2-methylpentanoic acid (Sigma-Aldrich, St. Louis, MO, USA, 98%), hexanoic acid (Alfa Aesar, Haverhill, MA, USA, 98+%), heptanoic acid (SAFC, St. Louis, MO, USA, 97%)), and silver nitrate (Alfa Aesar, Haverhill, MA, USA, 99.9+%) using a simple precipitation reaction modified from a protocol reported previously [21 (link)]. A solution of the carboxylic acid (3.5 mmol) and potassium hydroxide (Riedel-de-Haën, Seelze, Germany, >85%, 3.5 mmol) in a water–ethanol mixture (1:1 v/v) was stirred and an equal volume of a solution of silver nitrate in water (3.5 mmol) was slowly added. A white precipitate formed, which was filtered, washed with water and ethanol, and dried in vacuo. Ag(I) 3,3-dimethyl-1-butynyl was obtained from Oliver Feddersen Clausen (www.modularflow.com, accessed on 9 November 2021) and used as received.

DKT (99.8% purity) was provided by Laboratorios Infarma LTDA (Cartago, Costa Rica). Chitosan (MW: 100,000–300,000), PVA (MW: 89,000–98,000), and gelatin were purchased from Sigma Aldrich (St. Louis, MO, USA); citric acid monohydrate and benzoic acid from Merck (Kenilworth, NJ, USA). Distilled water was obtained from LABIOFAR facilities (San José, Costa Rica).