From db9452343cad6c5821b874923938e615563f7b33 Mon Sep 17 00:00:00 2001 From: romainsacchi Date: Mon, 26 Aug 2024 17:44:21 +0200 Subject: [PATCH] Update docs --- docs/transform.rst | 80 +++++++++++++++++++++++++++++++--------------- 1 file changed, 55 insertions(+), 25 deletions(-) diff --git a/docs/transform.rst b/docs/transform.rst index 4c54742d..f310329f 100644 --- a/docs/transform.rst +++ b/docs/transform.rst @@ -845,11 +845,49 @@ activities to the new regional markets. The regional market it re-links to depends on the location of the consumer. Cement production -+++++++++++++++++ +""""""""""""""""" -The modelling of future improvements in the cement sector is relatively -simple at the moment, and does not involve the emergence of new -technologies (e.g., electric kilns). +The modelling of future improvements in the cement sector is dependent on the IAM model chosen. + +When choosing IMAGE, scenarios include the emergence of a new, more efficient kiln, as well +as kilns fitted with three types of carbon capture technologies: + +* using monoethanolamine (MEA) as a solvent, +* using oxyfuel combustion, +* using Direct Separation (Leilac process). + +The implementation of the corresponding datasets for these new kiln technologies are based on the work of +Muller_ et al., 2024. + +.. _Muller: https://doi.org/10.1016/j.jclepro.2024.141884 + +We differ slightly from the implementation of Muller_ et al., 2024, in that: + +* the heat necessary for the regeneration of the MEA solvent is assumed to be provided by a natural gas boiler +(instead of a fuel mix resembling that of the kiln itself), with up to 30% coming from recovered heat from the kiln by 2050, +* the amount of heat needed for the regeneration of the MEA solvent goes from 3.76 GJ/ton CO2 in 2020, to 2.6 GJ/ton CO2 in 2050, +* the provision of oxygen for the Direct Separation option comes from an existing air separation dataset from ecoinvent, +* the fuel mix for the kiln is that of ecoinvent, further scaled down by the change of efficiency of the kiln +(in Müller et al., 2024, they use directly the fuel mix provided by the IMAGE scenario, which we do not find representative, +as it also includes the fuel used by other activities in the non-metallic minerals, notably a large share of natural gas). + +In a nutshell, *premise*: +* makes copies of the `clinker production` dataset, +* adjusts the fuel consumption and related CO2 emissions, +* adjusts specific hot pollutant emissions removed by the carbon capture process (Mercury, NOx, SOx), +* adds an input from the carbon capture process, based on a capture efficiency share, +* and removes a corresponding amount from the outgoing CO2 emissions. + +The Direct Separation process only captures calcination emissions, while the other two technologies capture +both combustion and calcination emissions. + +When choosing another IAM, the current implementation is relatively +simpler at the moment, and does not involve the emergence of new +technologies. In these scenarios, the production volumes of kilns +equipped with CCS is not given. Instead, the share of CO2 emissions +that is sequestered is given. We use the ratio of the CO2 emissions +sequestered over the total CO2 emissions to determine the share of +the CO2 emissions that is sequestered in the clinker production dataset Run @@ -887,17 +925,9 @@ Efficiency adjustment --------------------- *premise* then adjusts the thermal efficiency of the process. -It does so by calculating the technology-weighted energy requirements -per ton of clinker. -Based on GNR/IEA roadmap data, *premise* uses: -* the share of kiln technology for a given region today (2020): - * wet, - * dry, - * dry with pre-heater, - * and dry with pre-heater and pre-calciner - -* the energy requirement for each of these technologies today (2020). +It first calculates the energy input in teh current (original) dataset, +by looking up the fuel inputs and their respective lower heating values. Once the energy required per ton clinker today (2020) is known, it is multiplied by a *scaling factor* that represents a change in efficiency @@ -916,15 +946,16 @@ between today and the scenario year. .. note:: *premise* enforces a lower limit on the fuel consumption per ton of clinker. - This limit is set to 2.8 GJ/t clinker and corresponds to the minimum + This limit is set to 3.1 GJ/t clinker and is close to the minimum theoretical fuel consumption with an moisture content of the raw materials, - as considered in the 2018 IEA_ cement roadmap report. Hence, regardless of the - scaling factor, the fuel consumption per ton of clinker will never be less than - 2.8 GJ/t. + as considered in the 2018 IEA_ cement roadmap report (i.e., 2.8 GJ/t clinker). + Hence, regardless of the scaling factor, the fuel consumption per ton of clinker + will never be less than 3.1 GJ/t. .. _IEA: https://iea.blob.core.windows.net/assets/cbaa3da1-fd61-4c2a-8719-31538f59b54f/TechnologyRoadmapLowCarbonTransitionintheCementIndustry.pdf + Once the new energy input is determined, *premise* scales down the fuel, and the fossil and biogenic CO2 emissions accordingly, based on the Lower Heating Value and CO2 emission factors for these fuels. @@ -943,22 +974,21 @@ If the IAM scenario indicates that a share of the CO2 emissions for the cement sector in a given region and year is sequestered and stored, *premise* adds CCS to the corresponding clinker production dataset. -The CCS dataset used to that effect is from Meunier_ et al., 2020. -The dataset described the capture of CO2 from a cement plant. +The CCS dataset used to that effect is from Muller_ et al., 2024. +The dataset described the capture of CO2 from a cement plant, +using a monoethanolamine-based sorbent. To that dataset, *premise* adds another dataset that models the storage of the CO2 underground, from Volkart_ et al, 2013. Besides electricity, the CCS process requires heat, water and others inputs to regenerate the amine-based sorbent. We use two data points to approximate the heat -requirement: 3.66 MJ/kg CO2 captured in 2020, and 2.6 MJ/kg in 2050. -The first number is from Meunier_ et al., 2020, while the second number is described +requirement: 3.76 MJ/kg CO2 captured in 2020 (minus 30% coming from the kiln as recovered heat), +and 2.6 MJ/kg in 2050. The first number is from Muller_ et al., 2024, while the second number is described as the best-performing pilot project today, according to the 2022 review of pilot projects by the Global CCS Institute_. It is further assumed that the heat requirement -is fulfilled to an extent of 15% by the recovery of excess heat, as mentioned in -the 2018 IEA_ cement roadmap report. +is fulfilled to an extent of 30% by the recovery of excess heat, as found in numerous studies. -.. _Meunier: https://www.sciencedirect.com/science/article/pii/S0960148119310304 .. _Volkart: https://doi.org/10.1016/j.ijggc.2013.03.003 .. _Institute: https://www.globalccsinstitute.com/wp-content/uploads/2022/05/State-of-the-Art-CCS-Technologies-2022.pdf