diff --git a/doc/supply_demand.rst b/doc/supply_demand.rst index 5d1a6ca3..8e30346f 100644 --- a/doc/supply_demand.rst +++ b/doc/supply_demand.rst @@ -437,7 +437,7 @@ For the remaining subprocesses in this sector, the following transformations are The chemicals industry includes a wide range of diverse industries, including the production of basic organic compounds (olefins, alcohols, aromatics), basic inorganic compounds (ammonia, chlorine), polymers (plastics), and end-user products (cosmetics, pharmaceutics). -The chemicals industry consumes large amounts of fossil-fuel based feedstocks (see `Levi et. al `_), which can also be produced from renewables as outlined for hydrogen (see :ref:`Hydrogen supply`), for methane (see :ref:`Methane supply`), and for oil-based products (see :ref:`Oil-based products supply`). The ratio between synthetic and fossil-based fuels used in the industry is an endogenous result of the opti- misation. +The chemicals industry consumes large amounts of fossil-fuel based feedstocks (see `Levi et. al `_), which can also be produced from renewables as outlined for hydrogen (see :ref:`Hydrogen supply`), for methane (see :ref:`Methane supply`), and for oil-based products (see :ref:`Oil-based products supply`). The ratio between synthetic and fossil-based fuels used in the industry is an endogenous result of the optimisation. The basic chemicals consumption data from the `JRC IDEES `_ database comprises high- value chemicals (ethylene, propylene and BTX), chlorine, methanol and ammonia. However, it is necessary to separate out these chemicals because their current and future production routes are different. @@ -448,7 +448,7 @@ N_2 + 3H_2 → 2NH_3 $$ -The Haber-Bosch process is not explicitly represented in the model, such that demand for ammonia enters the model as a demand for hydrogen ( 6.5 MWh $_{H_2}$ / t $_{NH_3}$ ) and electricity ( 1.17 MWh$_{el}$ /t $_{NH_3}$ ) (see `Wang et. al `_). Today, natural gas dominates in Europe as the source for the hydrogen used in the Haber-Bosch process, but the model can choose among the various hydrogen supply options described in the hydrogen section (see :ref:`Hydrogen supply`) +The Haber-Bosch process is not explicitly represented in the model, such that demand for ammonia enters the model as a demand for hydrogen ( 6.5 MWh $_{H_2}$ / t $_{NH_3}$ ) and electricity ( 1.17 MWh $_{el}$ /t $_{NH_3}$ ) (see `Wang et. al `_). Today, natural gas dominates in Europe as the source for the hydrogen used in the Haber-Bosch process, but the model can choose among the various hydrogen supply options described in the hydrogen section (see :ref:`Hydrogen supply`) The total production and specific energy consumption of chlorine and methanol is taken from a `DECHEMA report `_. According to this source, the production of chlorine amounts to 9.58 MtCl/a, which is assumed to require electricity at 3.6 MWh $_{el}$/t of chlorine and yield hydrogen at 0.937 MWh $_{H_2}$/t of chlorine in the chloralkali process. The production of methanol adds up to 1.5 MtMeOH/a, requiring electricity at 0.167 MWh $_{el}$/t of methanol and methane at 10.25 MWh $_{CH_4}$/t of methanol. @@ -457,9 +457,8 @@ The production of ammonia, methanol, and chlorine production is deducted from th The process emissions from feedstock in the chemical industry are as high as 0.369 t $_{CO_2}$/t of ethylene equivalent. We consider process emissions for all the material output, which is a conservative approach since it assumes that all plastic-embedded $CO_2$ will eventually be released into the atmosphere. However, plastic disposal in landfilling will avoid, or at least delay, associated $CO_2$ emissions. - -Circular economy practices drastically reduce the amount of primary feedstock needed for the production of plastics in the model (see `Kullmann et al. `_, `Meys et al. (2021) `_, `Meys et al. (2020) `_, `Gu et al. `_) and consequently, also the energy demands and level of process emission (LINK TO PROCESS EMISSIONS FIGURE). We assume that 30% of plastics are mechanically recycled requiring 0.547 MWh $_{el}$/t of HVC (`Meys et al. (2020) `_), 15% of plastics are chemically recycled requiring 6.9 MWh $_{el}$/t of HVC based on pyrolysis and electric steam cracking (see `Materials Economics `_ report, and 10% of plastics are reused (equivalent to reduction in demand). The remaining 45% need to be produced from primary feedstock. In comparison, Material Economics presents a scenario with circular economy scenario with 27% primary production, 18% mechanical recycling, 28% chemical recycling, and 27% reuse. Another new-processes scenario has 33% primary production, 14% mechanical recycling, 40% chemical recycling, and 13% reuse. - +Circular economy practices drastically reduce the amount of primary feedstock needed for the production of plastics in the model (see `Kullmann et al. `_, `Meys et al. (2021) `_, `Meys et al. (2020) `_, `Gu et al. `_) and consequently, also the energy demands and level of process emission. The percentage of plastics that are asumed to be mechanically recycled can be selected in the `config file `_, as well as +the percentage that is chemically recycled `config file `_ The energy consumption for those recycling process are respectively `0.547 MWh $_{el}$/t of HVC `_ (`Meys et al. (2020) `_), and `6.9 MWh $_{el}$/t of HVC of HVC `_ based on pyrolysis and electric steam cracking (see `Materials Economics `_ report, ). **Non-metallic Mineral Products**