The Potential of Power and Biomass-to-X Systems in the Decarbonization Challenge: a Critical Review

Abstract

Purpose of the Review The scope of this work is to present a critical review of the novel class of plants for the enhanced production of bioproducts in power and biomass-to-X (PBtX) plants, where the excess carbon in the feedstock is converted into a product thanks to the addition of hydrogen from water electrolysis, rather than being vented as CO2. Recent Findings The review of the recent literature shows that (i) a significant gain in carbon efficiency can be achieved with this class of plants compared to corresponding biomass-to-X plants; (ii) there is high dependency of the power-to-X efficiency on the efficiency of the electrolysis system and a relatively low dependency on the final product; and (iii) the economic competitivity of PBtX plants is closely associated to the cost of hydrogen (i.e., electrolysis capital cost, electricity cost, and capacity factor) and such systems cannot rely only on green hydrogen from the low expected amounts of excess electricity from intermittent renewables. Summary In this work, through a simplified economic analysis, the region of competitiveness of this class of plants compared to other possible uses of biomass has been qualitatively identified. The research gaps mainly lie in the lack of assessments on the design and operating criteria of flexible PBtX plants and of studies providing insights on the value of flexibility for a PBtX plant, when integrated in the electric energy systems of the future.

Flexible methanol and hydrogen production from biomass gasification with negative emissions

“…As discussed in ref. 10 bioenergy plants integrated into the broader energy system may be required to cope with the intermittency of renewable energy sources (RES), that lead to variable prices of electricity on hourly time-scales and may lead to variable hydrogen prices on dailymonthly time scales depending on the cost of storage and on the exibility of the market demand. Therefore, the expected time-dependent relative values of power, carbon-based products, hydrogen, and sequestered CO 2 may lead to economic benets for plants integrated with electrolysis units increasing carbon utilization and product yield during low electricity price periods 11,12 and for multi-product plants operated exibly to produce goods generating the highest revenues.…”

Flexible Power and Biomass-To-Methanol Plants With Different Gasification Technologies

“…In this framework, power and biomass-to-X (PBtX) plants aim to optimize the utilization of the biogenic carbon by integrating with water electrolysis to produce increased amounts of generic products "X," which may include fuels and chemicals. Poluzzi et al (2021) reviewed the most significant scientific papers on techno-economic analysis of PBtX plants within the scientific literature. This kind of plants enhances the production of bioproducts by converting the excess biogenic carbon contained in the feedstock through the addition of hydrogen from water electrolysis rather than venting it as CO 2 .…”

Optimal Renewable Energy Distribution Between Gasifier and Electrolyzer for Syngas Generation in a Power and Biomass-to-Liquid Fuel Process

“…It is clear from the studies performed in the literature (Agrawal and Singh, 2009;Bernical et al, 2012;Lysenko et al, 2012;Newport et al, 2012;Schaub et al, 2013;Hannula, 2016;Dietrich et al, 2018;Hillestad et al, 2018;Karl and Pröll, 2018;Ostadi et al, 2019;Poluzzi et al, 2021) that addition of energy to the BtL process, either in the form of hydrogen or directly to the gasifier, improves the carbon efficiency. Here, the process concept with energy addition to the BtL process is further improved by optimally distributing the amount of energy added through SOEC as hydrogen and directly to the gasifier as heat.…”