What is still Limiting the Deployment of Cellulosic Ethanol? Analysis of the Current Status of the Sector

Abstract

Ethanol production from cellulosic material is considered one of the most promising options for future biofuel production contributing to both the energy diversification and decarbonization of the transport sector, especially where electricity is not a viable option (e.g., aviation). Compared to conventional (or first generation) ethanol production from food and feed crops (mainly sugar and starch based crops), cellulosic (or second generation) ethanol provides better performance in terms of greenhouse gas (GHG) emissions savings and low risk of direct and indirect land-use change. However, despite the policy support (in terms of targets) and significant R&D funding in the last decade (both in EU and outside the EU), cellulosic ethanol production appears to be still limited. The paper provides a comprehensive overview of the status of cellulosic ethanol production in EU and outside EU, reviewing available literature and highlighting technical and non-technical barriers that still limit its production at commercial scale. The review shows that the cellulosic ethanol sector appears to be still stagnating, characterized by technical difficulties as well as high production costs. Competitiveness issues, against standard starch based ethanol, are evident considering many commercial scale cellulosic ethanol plants appear to be currently in idle or on-hold states.

Isomerization of n-C5/C6 Bioparaffins to Gasoline Components with High Octane Number

“…As a result of persistent research and development in the last few years, the construction of plants using lignocellulose as feedstock has already begun [9]. However, their technological efficiency and reliability need to be proven [10].…”

Lignocellulosic Ethanol in a Greenhouse Gas Emission Reduction Obligation System—A Case Study of Swedish Sawdust Based-Ethanol Production

“…A large proportion of the fuel production cost of a crop-based biofuel is the cost of the biomass feedstock, while the production of advanced biofuels requires installations with higher investment costs [6,14]. Globally, advanced ethanol production has stagnated, mainly due to technical difficulties and high production costs [15], and advanced ethanol made up less than 2% of the ethanol used in Sweden in 2018 [5]. The considerable financial risk means that long-term stable political incentives will be required for this type of ethanol production to be commercialized [6].…”

“…Several previous studies have shown that lignocellulosic ethanol production systems require economic support to be competitive with existing crop-based ethanol production systems, and especially so compared to fossil liquid fuels [15,[52][53][54]. The estimated production cost in the large-scale commercial production of lignocellulosic ethanol has been reported to be up to 30% higher than the production cost using existing wheat-based ethanol production in Sweden [47,51].…”

“…A recent summary of the costs of producing advanced ethanol (i.e., from agricultural residues and woody biomass) found them to be in the range of 0.51-1.2 €/L [15]. In a techno-economic assessment focusing on woody biomass [16], it was concluded that the minimum ethanol selling price, ensuring profitable production, varied between 0.55 and 1.1 €/L ethanol.…”

Morphological composition and fiber partitioning along regrowth in elephant grass CT115 intended for ethanol production

“…Second-generation ethanol derives from lignocellulosic raw materials, while first-generation ethanol derives from starch rich crops like corn or from sucrose rich crops such as sugarcane 1 . Despite the industrial production of second-generation biofuels yet being incipient; substantial research is being conducted for both production and conversion of raw materials 2 . Among the energetic crops, perennial grasses stand as the leading alternative, as their use overcome the major drawbacks of both the fossil fuels and the first-generation biofuels.…”