Selective Catalysis for One-Step Lignocellulose Delignification and Lignin Valorization to High Value Methoxyphenols

The U.S.s global leadership position in the manufacture of high value chemicals (HVCs) relies on its ability to produce and utilize simple and useful organic (SUO) building block chemicals, a $400 billion a year enterprise based on nonrenewable petroleum feedstock. To maintain U.S.s leadership position in the 21st century, we must seek alternate renewable and economically competitive sources for making HVCs that are used in polymers, medicines, advanced materials, and flavor and fragrance applications. Lignin, a natural biopolymer of monomeric phenol subunits, is a rich source of aromatic building block chemicals and contains about 40% of the total carbon of plants. Current biorefinery strategies primarily focused on valorization of carbohydrates of biomass because of lack of selective catalyst for lignin conversion. As a result, >98% of 70 million tons of lignin annually produced by global paper pulping industries and biorefineries is neglected as a biorenewable feedstock and is typically burned for low value fuel. However, lignin value and hence the profitability of the current lignocellulose processing industries can be significantly improved by selective upgrading of lignin into high value products that can be used as green alternative to many petroleum-derived products. Spero Energy, Inc. has a proprietary catalytic technology for one-step lignocellulose deconstruction and selective conversion of wood lignin into high value flavor and fragrance chemicals, dihydroeugenol (DHE) and 2,6-dimethoxy-4-propylphenol (DMPP) of average market price of $22.5 per kg, with the simultaneous production of digestible cellulose. The combined global market of our lignin derived DHE, DMPP and the derivate aroma chemicals is about $1.1 billion per year. Using the SBIR Phase I financial support from the Department of Energy, Spero Energy has achieved several critical milestones including evaluation of feedstock flexibility, catalyst stability and lifespan analysis, and digestibility studies of the cellulose product. The critical objectives of the Phase II technology development includes (1) process scale up to assess and mitigate scale up risks, (2) enhance operational efficiency of the process under continuous operation conditions, (3) process design and process parameters optimization, (4) produce products in quantities for industrial standard quality testing with reference to the benchmark of the current products and determine any unique properties of our products that may give additional competitive advantages and (5) complete detailed techno-economic analysis. The ultimate goal is to deliver a risk-free process on mini-pilot scale by the end of Phase II performance period so that the technology can be rolled out to pilot scale during the Phase III and the products can hit the target entry market. On broader aspect, our technology provides a unique solution for upgrading the entire woody biomass selectively into high value downstream products with high carbon efficiently. Our long term strategy of upgrading the initial lignin products (DHE and DMPP) into commodity chemicals and aromatic fuel additive will bring significant societal and educational benefits for producing such products in a new way from lignin.