Zeolite-Based Catalysis for Phenol Production

Abstract

Phenol is an important chemical commodity utilized for several applications (e.g., polycarbonate, epoxy–resins, phenolic resins, nylon). Its conventional production starts from benzene and propylene and is based on a series of reaction steps most of which are catalyzed by acid catalysts. Besides this technology other ones have been considered during the last decades, starting from other reactants and catalysts. Looking at the catalyst types both already in use or under evaluation, it is interesting to note that zeolites, as acidic catalysts or red-ox catalysts, were widely investigated. Therefore, the production of phenol represents a fascinating example of how zeolite catalysis contributes to improving the sustainability of these chemical processes by displacing the previous large use of corrosive and dangerous liquid acids and improving overall selectivity, which reduces the side production of wastes. Aromatic alkylation, transalkylation, and disproportionation, oxidations, rearrangements, oligomerization, and cracking are the reactions occurring in phenol production technologies, but also key unit operations in refineries and the chemical industry. A review of the zeolite catalysts utilized and proposed by major licensors and research groups in these technologies is provided as well as a discussion of key process differences and recent advances.

Current State and Perspectives of Exfoliated Zeolites

“…[65,113] The XRD pattern of MWW nanosheets is one of the most analyzed examples, including theoretical simulation, which match experimental profiles. [44,[113][114][115] The pattern contains relatively sharp peaks due to 100, 200, 220, and 310 reflections and a broad band without a valley between 8 and 10°2𝜃 (CuK𝛼 radiation everywhere, except when specified otherwise). The band is instead of 101 and 102 reflections in the 3D structure, at 8 and 10°2𝜃, respectively, indicating absence of order in the 3rd dimension.…”

Computational Study of Alkane Adsorption in Brønsted Acid Zeolites for More Efficient Alkane Cracking

“…Approximately 30% of propylene, the second most important chemical after ethylene, is produced through fluid catalytic cracking . In these processes, Brønsted acid zeolites have been widely used as the catalysts. − Zeolites are microporous aluminosilicates comprising networks of SiO 4 4– and AlO 4 5– . Brønsted acid sites form when a negatively charged oxygen of AlO 4 5– is compensated for by a catalytically active Brønsted proton.…”

Turning the Light on Phenols: New Opportunities in Organic Synthesis

“…Most of the phenol available on the global market is derived from the direct oxidation of benzene [8] . Among several industrially relevant processes, phenol is principally produced via a multistep and indirect synthesis, namely the cumene process [9] .…”

“…[7] Most of the phenol available on the global market is derived from the direct oxidation of benzene. [8] Among several industrially relevant processes, phenol is principally produced via a multistep and indirect synthesis, namely the cumene process. [9] However, this process has several disadvantages that include high consumption of energy and the need for fossil raw chemicals.…”