SBIR-STTR Award

Organic acid esters, produced from bio-based organic acids and alcohols, are truly bio-renewable, green chemicals that are promising replacements for halogenated and other petroleum-based solvents, lubricants, and plasticizers. With current uncertainty regarding the future of ethanol and other alcohols as biofuels, and with the availability of organic acids via fermentation, there exists strong motivation to develop esters as viable commodity bio-chemicals to support and expand the existing bio-renewable infrastructure. Esters are advantageously produced using reactive distillation, where simultaneous reaction and separation take place in the same process unit. Because of challenges in some esterification reactions, where reactions are slow and limited thermodynamically, there exists a need for breakthrough advances in reactive distillation to make the production of esters more competitive economically with their petroleum-based counterparts. This project will develop and demonstrate advanced reactive distillation concepts for esterification that reduce energy consumption and lower capital equipment costs. The major objective is to develop and experimentally validate design concept(s) of heat-integrated reactive distillation with side reactors and divided-wall columns for esterification of bio-based organic acids with alcohols and to evaluate techno-economic viability for near-term commercialization. The Phase I proposed project focuses on an innovative, heat-integrated reactive distillation with side reactors and divided-wall column for synthesis of organic acid esters. AspenPlus process analysis will be performed based on the available kinetic data for esterification of citric acid with ethanol and it will be validated by preliminary reactive distillation experiments. The experimental part of the Phase 1 research will use the reactive distillation facility at Michigan State University with a pre-reactor and one side reactor coupled to a distillation column. Heat integration will be examined for energy efficiency and maintaining temperatures in side reactors for maximizing the catalyst utilization. Phase II research will focus on pilot-scale experiments and industrial participation to develop design basis for a commercial process. Commercial Applications and Other

Benefits:
The major benefits are: a) synthesis of high-value green chemicals from bio-based ethanol and organic acids; and b) U.S. competitiveness in manufacturing of bio-based plasticizers and solvents.

The global market for bio-based chemicals is at a critical stage of development, with focus on new bio-based routes to chemicals and building the type of commercial-scale plants that will enable the market to truly compete with petroleum derived chemicals. The 2011 Frost & amp; Sullivan report identifies six market challenges associated with bio-based chemicals production: 1) price volatility; 2) the continuing dominance of petroleum-based fuel as the primary product; 3) overcoming the end users lack of knowledge about bio-based chemicals; 4) competing against mature petrochemical technologies; 5) competing for attention with other sustainability factors; and 6) attracting equity investment in bio-based industry development. Along with market and financial issues, these challenges clearly point to the need for further development of processing strategies for bio-based chemicals and fuels in order to foster broad commercialization. Organic acid esters, produced from bio-based organic acids and alcohols, are truly bio-renewable, green chemicals that are promising replacements for halogenated and other petroleum-based solvents, lubricants, and plasticizers. This project will develop and demonstrate advanced reactive distillation concepts for esterification that reduce energy consumption and lower capital equipment costs. The governing objectives of the proposed Phase II research are: a) to develop experimentally validated design methodology for scaling the test data from MSUs pilot-plant to commercial unit; b) to demonstrate performance of integrated HIRD with side reactors and PerVap for esterification of multi-functional organic acids; c) to establish the energy and economic merits of HIRD with side reactors and PerVap membrane for manufacturing ester-based plasticizers; and d) to develop a roadmap for commercialization of HIRD with side reactors for synthesis of bio-based esters. The Phase II work plan will advance the technology from TRL-4 to TRL-5, or perhaps to TRL-6, with focus on licensing the technology to industrial partner(s). In terms of the DOE BioEnergys Stage-Gate process, Phase II will advance the technology from Stage-2 to Stage-3. The major tasks consists of a) development of design methodology of heat integrated reactive distillation with side reactors and PerVap membranes; b) preliminary design of a pre-commercial plant; c) pilot- plant tests; d) techno-economic analysis of manufacturing bio-based esters to replace phthalate plasticizers; and e) developing a commercialization roadmap, including holding an industry workshop. Commercial Applications and Other

Benefits:
The major benefits that will arise from this project are: a) enhanced U.S. competitiveness in manufacturing of bio-based plasticizers and solvents; and b) process intensification and energy efficiency for broad-based manufacturing of bio-based chemicals in the modern biorefinery.