Potential emission reductions by converting agricultural residue biomass to synthetic fuels for vehicles and domestic cooking in China

Vehicle exhaust and transported biomass burning emissions are important air pollution sources in many urban areas,and domestic cooking with biomass fuels causes indoor air pollution in many rural areas.Using agricultural waste-generated synthetic fuels can reduce emissions both from vehicles and biomass burning.To estimate the potential benefits of synthetic diesel in Beijing,the emission factor model for the Beijing vehicle fleet was applied to estimate exhaust emissions for the 2015-2030 period.Compared with 100%petroleum diesel,a 20%synthetic diesel blend reduced diesel fleet emissions by 24%for carbon monoxide,30%for total hydrocarbons,5.5%for nitrogen oxides,and 19%for fine particulate matter with an aerodynamic diameter of≤2.5μm(PM2.5)while using 100%synthetic diesel decreased emissions by 36%for carbon monoxide,48%for total hydrocarbons,10%for nitrogen oxides,and 34%for PM2.5.The use of biomass for producing synthetic fuels rather than burning in the field also reduces air pollution.Over 60g of PM2.5 agricultural open-field burning emissions are avoided per liter of synthetic fuel produced.Replacing solid crop residues with synthetic liquid fuels in household cooking would reduce PM2.5 emissions by more than 90%.

Cost projections for microwave plasma CO production using renewable energy

Successful deployment of renewable fuel production requires substantial cost reduction along the entire value chain of the underlying manufacturing routes.To improve their performance,renewable fuel production technologies should follow a cost-reducing learning curve.In this article,we adopt recent evidence that learning-by-doing is directly influenced by the technology unit size and explore three scenarios for microwave plasma CO_(2)conversion in which the learning rate varies between 10%,15%,and 20%.Our projections reveal that the total investments required to deploy this CO_(2)conversion technology at an exajoule scale decline from 83 down to 23 billion euros under a 10%increase in the value of the learning rate.The CO_(2) production costs in 2050 amount to 247–346€(2019)/t CO_(2),in which the range is determined by the value of the learning rate.Even under substantial learning until 2050 the levelized CO production cost is unlikely to become competitive with conventional natural gas-based CO_(2) production processes,except when a CO_(2)tax is applied of up to 150€(2019)/t CO_(2).To optimally exploit effects of learning-by-doing,we recommend developing several CO production technologies simultaneously with multiple unit sizes,so as to improve the chance of ultimately selecting the process with the highest learning rate.

Hydroprocessing and Blending of a Biomass-Based DTG-Gasoline

The number of annually registered internal-combustion vehicles still exceeds electric-driven ones in most regions,e.g.,Germany.Ambitious goals are disclosed with the European Green Deal,which calls for new technical approaches and greenhouse gas neutral transition technologies.Such bridging technologies are synthetic fuels for®the transportation sector,e.g.,using the bioliq process for a CO_(2)-neutral gasoline supply.Fuels must meet the applicable national standards to be used in existing engines.Petrochemical parameters can be variably adapted to their requirements by hydroprocessing.In this work,we considered the upgrading of aromatic-rich DTG®gasoline from the bioliq process.The heavy gasoline was therefore separated from the light one by rectification.We investigated how to selectively modify the petrochemical parameters of the heavy gasoline,especially the boiling characteristics,to make the product suitable as a high-quality blending component.Three commercially available Pt/zeolite catalysts were tested over a wide range of temperature and space velocity.We achieved high gasoline yields,while the content of light end compounds up to a boiling temperature of 150°C could be increased significantly.In contrast to the high naphthenic content of the gasoline,the obtained octane numbers were satisfactory.Especially the Motor Octane Number turned out unexpectedly high and showed a dependency on the isomerization of the naphthenic rings.By blending the upgraded heavy gasoline with the previously separated light gasoline,we could finally show that hydroprocessing is suitable for adjusting petrochemical parameters.The aromatic concentration was 37.5%lower than that in the original raw gasoline,while the boiling characteristics improved significantly.Additionally,the final boiling point was 82°C lower,which is beneficial for the emission behavior.

Chemical storage of hydrogen in synthetic liquid fuels:building block for CO_(2)-neutral mobility

Green hydrogen is anticipated to play a major role in the decarbonization of the mobility sector.Its chemical storage in CO_(2)-neutral synthetic liquid fuels is advantageous in terms of safety and reliability compared to other hydrogen storage developments,and thus represents a complementary building block to developments in electric and hydrogen mobility for the low-carbon transition in the mobility sector.Its development is especially relevant for transport sectors which will have no alternatives to liquid fuels in the foreseeable future.In this paper,three alternative technological routes for the chemical storage of hydrogen in CO_(2)-neutral synthetic liquid fuels are identified and comparatively evaluated in terms of feedstock potential,product potential,demand for renewable electricity and associated costs,efficiency as well as expected market relevance.While all three routes exhibited similar levels of overall efficiencies,electricity-based liquid fuels in Germany are currently limited by the high cost and limited supply of renewable electricity.In contrast,liquid fuels generated from biogenic waste have a constant supply of biogenic feedstock and are largely independent from the supply and cost of renewable electricity.