Synthesis of Zeolites from Production Sand Waste: The Circular Model for Oil and Gas Exploration and Production

Abstract

This project aims to convert production sand waste from oil & gas exploration & production process to be high value silica-based product, Zeolites, and explore opportunities to lower amount of sand waste disposal to landfill. This is one key item in Circular Model for Oil & Gas Exploration & Production. Zeolites is a microporous crystalline aluminosilicate material, which possess a superior characteristic in terms of high surface area. Therefore, it is widely utilized in many industries such as adsorbent, ion exchange, and catalysts in oil refining and petrochemical industry. In this work, various types of zeolites were synthesized from PTTEP production sand waste, to prove concept of turning sand waste to high value-added product, called zeolite. In normal operation, sand waste was sent to dispose as landfill about 50 Ton/annual. To synthesize zeolite from sand waste, there are three main steps, which are 1) Sand Pretreatment, 2) Silica Extraction, and 3) Zeolite Synthesis. Firstly, sand waste from petroleum production were pretreated by water and acid washing. Then, nanosilica was extracted out from pretreated sand by boiling the pretreated sand in NaOH solution at temperature 150 C for 4 hrs, then precipitate them to get the nanosilica substances. It was further used as a reactant source for zeolite synthesis. In the last step, the extracted silica was reacted with Structure Directing Agent (SDA); zeolite template, under optimal condition of hydrothermal treatment process to obtain zeolites product. Zeolites synthesis from production sand waste was firstly initiated and successfully achieved in lab phase, to prove of concept for extracting silica source as a substance for zeolite synthesis. Various types of zeolites (Silicalite-1, ZSM-5, Faujasite (FAU), Mordenite, and Zeolite A) can be synthesized from PTTEP sand waste with synthesis yield 80%, 68%, 85%, 40%, and 81%, respectively. This indicates that silica source from production sand waste can be utilized as a reactant source for zeolites synthesis. The next phase of prototype unit is under design phase, to allow unit can be operated more versatile, and automatically run. From this novel technology, it is expected to reduce an amount of production sand waste disposal out from separator to landfill about 50 Ton/year. The synthesized zeolites from prototype phase will be further applied in many potential applications such as an adsorbent in wastewater treatment process, as catalyst, and moisture adsorbent in oil & gas dehydration unit. New findings and requirements discovered during the prototype test will be used to iteratively optimize and improve the design of the sand to zeolites process for future industrial-scale implementation.