6 BECCS - Bioenergy with Carbon Capture and Storage
Burning plants and burying the carbon
Anderson
Biomass carbon removal and storage involves using biomass (such as algae, municipal waste, agricultural or forest residues) to remove CO2 from the atmosphere and store it underground or in products. It looks promising in many areas but is very context-dependent. There are a number of methods that deserve more research, including ocean alkalinity enhancement, enhanced rock weathering and agrigenomic ideas such as engineering plants for enhanced carbon sequestration or microbe-based carbon capture soil amendments. It is early to assess the scalability of all these approaches, and much of the scalability depends on culture and policy. The IPCC assesses that moderate-to-large future mitigation potentials are estimated for direct air carbon capture and sequestration, enhanced weathering and ocean-based CDR methods, with medium evidence and medium agreement.
As an engineer with a background in design and construction in the petrochemical industry, I feel a streak of professional shame when, in 2023, the pinnacle of engineering prowess is burning plants and burying the carbon (termed BECCS).
There are many reasons for this shame, but key amongst these is the very low energy density of plants. Add this to the inefficiencies in thermal electricity generation and nation-sized areas of land needed to be put aside to deliver the volumes of BECCS assumed in the IAM models. Yet, with very few exceptions, it is such an unsustainable and yesteryear approach to current problems that the IAM modelling groups evoke on a huge planetary scale. So, for me, and on so many levels, BECCS is a blunder of monumental proportions and illustrates just how low we are prepared to stoop to get the carbon molecules to add up in models.