Avaliação econômica e ambiental de um novo processo de produção de 1,3-propanodiol a partir do glicerol bruto

Abstract

The significant availability of glycerol derived from biodiesel presents an economic opportunity for its use as a low-cost raw material to produce high-value-added chemicals. 1,3-propanediol (1,3-PDO) is a specialty chemical of commercial interest to obtain high-performance polymers, and it is currently obtained in large scale from glucose through DuPont's biotechnological process. The utilization of glycerol enables the development of new production routes for 1,3-PDO that can economically and environmentally compete with the biotechnological pathway, aiming to expand its market. In this context, this study assesses the current market and growth prospects for glycerol and 1,3-PDO, proposes a novel process to produce 1,3-PDO through the hydrogenolysis of glycerol, followed by a technical-economic feasibility study (EVTE) and a comparative life cycle analysis (ACV) with a representation of the existing commercial biotechnological process. The catalytic route was developed using the Aspen Plus® software, and the ACV was based on Ecoinvent data and simulated using SimaPro®, employing TRACI and Environment Footprint methods for assessing environmental impacts. The proposed catalytic route yielded superior results compared to the biotechnological pathway, both in terms of economic and environmental aspects. The proposed route demonstrates cost-effectiveness and competitiveness in relation to the biotechnological process, with a net present value to investment ratio (NPV/INV) of 2.03, an internal rate of return (IRR) of 38%, and a 18% lower production cost of 1,3-PDO compared to the biotechnological route. These gains are primarily attributed to reduced investment for constructing the new plant and lower energy demand during operation. The proposed led to fewer environmental impacts, particularly in categories like ecotoxicity, scarcity of fossil sources, and water usage, when compared to the biotechnological process. Catalytic route environmental improvements in these categories are linked to reduced consumption of natural gas and water compared to the biotecnological one. It was found that the glycerol purification step in the proposed route contributes the most to environmental impacts due to the use of sodium hydroxide as a homogeneous catalyst in biodiesel and glycerol production. The use of zeolite Y as a heterogeneous catalyst, in relation to the homogeneous one, could enhance process yield and decrease environmental impacts during glycerol separation, resulting in a significant reduction in generated waste. The process of obtaining 1,3-PDO from glycerol is scalable and has the potential to become a competitive pathway alongside commercial biotechnological production, transforming the product into a commodity.