This is a type of biorefinery which uses only one type of feedstock, and converts it with a single process into one end product. This is the simplest and oldest type of biorefinery and nowadays it is in operation and economically viable. The disadvantage of a phase I biorefinery is that there is no flexibility in the processes that are used or the products that are formed. It is therefore not possible to adapt the production to meet changing market demands.

Biodiesel is produced in Europe in phase I biorefineries, where rapeseed is first pretreated and then transesterified to FAME with $\text{MeOH}$ and a catalyst to obtain biodiesel as the major product. Glycerine and the meal are by-products and are usually not used for other purposes, which makes a biodiesel production plant a phase I type of biorefinery.

Applications: Alkylpolyglucosides (APGs) are used as surfactant molecules in detergents and personal care products. They consist of several oligomerized glucose molecules attached to a long-chain fatty alcohol.

Synthesis: The reaction can be either acid- or base-catalyzed:

• Acid-catalyzed reaction (Fischer glycosylation): The hydroxyl group at position 1 is protonated and eliminated. $\text{OH}$-groups of other glucose molecules can then react onto this position to form glucose poly- or oligomers. Also, the fatty alcohol added to the reaction mixture can perform a nucleophilic attack to form the APG.
  • Role of butanol: The glycoside moiety is hydrophilic while fatty alcohols are hydrophobic. A direct one-step process is therefore difficult and proceeds very slowly due to phase separation. The solution is a two-step process where butanol is added to form a butylated intermediate, improving miscibility. This intermediate is subsequently transacetalized to the long-chain APG by adding fatty alcohols under vacuum (removing butanol).
• Base-catalyzed reaction (Koenigs-Knorr glycosylation): Uses a base and fatty alcohols. To prevent unselective deprotonation of multiple hydroxyl groups, the $\text{OH}$ at the anomeric carbon is first replaced by a bromine atom ($\text{Br}$), turning it into a good leaving group. The other $\text{OH}$-groups are protected (e.g. as acetate groups). The base selectively deprotonates the fatty alcohol, which undergoes an $\text{S}_\text{N}2$ substitution at the anomeric carbon to form the alkyl-D-pyranoside.

Catalysts:

• Homogeneous catalyst: Mineral acids ($\text{HCl}$, $\text{H}_2\text{SO}_4$) or $p$-toluenesulfonic acid ($p$-TsOH).
• Heterogeneous catalyst: Acidic sulfonic ion-exchange resins.

Reaction mechanism: Both coniferyl alcohol units ($\text{G}$) are oxidized enzymatically to radical species via abstraction of a phenolic hydrogen radical. This radical delocalizes across the aromatic ring and propenyl side chain. Two radicals couple: one through the phenoxy oxygen radical and the other via the radical at the $\beta$-carbon of the double bond. Subsequent nucleophilic addition of water across the quinone methide intermediate yields the $\beta\text{-O-}4$ ether linkage.

Zip-lignin strategy: The zip-lignin strategy genetically introduces ester bonds (or other labile linkages) directly into the lignin backbone during lignification (e.g., using monolignol ferulate conjugates). These ester linkages are significantly easier to cleave chemically under mild alkaline conditions compared to traditional $\text{C-C}$ or ether bonds, facilitating facile depolymerization. This is an example of the green engineering principle design for deconstruction.

• Lower density: Lower density compared to glass fibers, resulting in significant weight reduction and lower material mass requirements.
• Mechanical properties & recyclability: Although their absolute tensile strength is lower than synthetic fibers (yet sufficient for many structural applications), lower energy is needed to mechanically recycle or grind them down at the end-of-life; they are also biodegradable.
• Cost-effective: Generally cheaper to produce than synthetic fibers (e.g. glass or carbon fibers).
• Environmental benefits: Renewable raw material with lower process emissions; photosynthetic $\text{CO}_2$ sequestration during plant growth and less toxic waste upon disposal.
• Vibration and acoustic damping: Natural cellular structures (e.g. flax) absorb mechanical vibrations effectively because van der Waals forces and hydrogen bonds between cellulose and hemicellulose break and dissipate energy upon impact.
• Low capital investment: Low-energy and low-cost agricultural processing compared to mineral melting or chemical fiber spinning.

(Voorbeeld op basis van het MixAlco-proces)

• Green Chemistry Principles:
  • Use of Renewable Feedstocks: Diverse non-food biomass sources can be used, ranging from municipal solid waste and sewage sludge to lignocellulose and chicken manure.
  • Catalysis: Zeolite catalysts are applied for the esterification of mixed carboxylic acids and subsequent oligomerization to fuels, avoiding stoichiometric reagents.
  • Waste Prevention: Undigested fermentation residues are gasified into syngas (to generate process heat and steam) and biochar (usable as fertilizer or soil conditioner).
• Green Engineering Principle:
  • Integrate Local Material and Energy Flows: Co-locating biorefineries near organic waste generators (e.g. adjacent to industrial livestock farms) minimizes transportation energy and closes nutrient loops.

A genetically modified potato variety developed by BASF designed to produce pure amylopectin starch (nearly 100%), knocking out the granule-bound starch synthase enzyme responsible for amylose synthesis. Industrially, isolating amylose from amylopectin is expensive and energy-intensive; hence, Amflora represents the green engineering principle of design for separation. Amylopectin is utilized as a thickening and binding agent in paper and adhesive manufacturing. The potato carried an antibiotic marker gene (kanamycin/neomycin resistance), raising biosafety concerns regarding horizontal gene transfer. It was intended strictly for industrial, non-food applications.

A pulping/pretreatment method using organic solvents (frequently aqueous ethanol, acetone, or methanol) at elevated temperatures ($150\text{--}200\ ^\circ\text{C}$) to separate lignocellulosic biomass into pure streams. Lignin hydrolyzes and dissolves in the organic medium, leaving a solid, high-purity cellulose pulp suitable for paper or enzymatic hydrolysis. Upon flashing/cooling and adding water as an anti-solvent, high-purity, sulfur-free organosolv lignin precipitates, which can be directly valorized for materials, resin formulations, or chemical aromatics.

An electrochemical membrane separation process used to fractionate protein hydrolysate mixtures into acidic, neutral, and basic amino acids. Under slightly alkaline pH in an applied electric field, negatively charged amino acids ($\text{Asp}$, $\text{Glu}$) migrate toward the anode through anion exchange membranes (AEM), while positively charged species ($\text{Lys}$, $\text{Arg}$) migrate toward the cathode through cation exchange membranes (CEM). Zwitterionic/neutral amino acids do not migrate across charge-selective membranes and remain in the central diluate channel, allowing salt-free fractionation.

A saturated $\text{C}_9$ $\alpha,\omega$-dicarboxylic acid utilized in the production of polyamides, polyester plasticizers, and anti-acne pharmaceuticals. Produced from oleic acid via:

1. Epoxidation followed by hydrolysis to 9,10-dihydroxystearic acid, subsequently cleaved oxidatively with $\text{O}_2$ and cobalt catalysts into pelargonic acid ($\text{C}_9$ monocarboxylic acid, used as a bio-herbicide) and azelaic acid; or
2. Ozonolysis of oleic acid directly cleaving the $\text{C}9\text{=C}10$ double bond. The resulting mixture is fractionated by multi-step vacuum distillation and water recrystallization to achieve $>99.1%$ polymer-grade purity.