Biogenic silica has been considered as a potential feedstock for producing a variety of silicon-containing products. A new synthesis pathway of tetraethyl orthosilicate from silica that is contained in rice hull ash has been recently proposed. Requiring only one-step processing, it is expected to offer advantages over conventional routes which are derived from silicon metal. This study aims to investigate the optimal synthesis conditions for which this new technology can sustainably replace the conventional method. Experiments employing different reaction conditions are performed to provide the necessary information for a conceptual process design and an economic and environmental viability evaluation. The results obtained by comparison with a selected conventional process show that, under the optimal synthesis conditions, the new process can decrease the production cost and markedly reduce the high greenhouse gas emissions. The competitiveness of the new process is further examined with a sensitivity analysis considering fluctuations in key feedstock and utility prices and alternative sources of electricity supplied to the conventional process. The new synthesis technology shows high potential as a sustainable alternative to the conventional one.