A Comparative Study for the Development of Coal-to-Liquids Industries in China, South Africa and United States

Many energy consuming countries have carried out research, development, demonstration, planning and deployment of coal-to-liquids (CTL) because of its ability to replace oil imports by converting coal resources into fuel. Among them, China and South Africa successfully had their CTL technology industrialized, while the United States did not. To understand the differences in the industrial development level, a comparative study is necessary. This paper compares the history, driver and policy of CTL industry in China, South Africa and United States, collates and discloses numbers of industry details for the first time. We figure out that the motivation, top level planning and policy consistency are the key indicators of the difference on the industrial development level. Among them, the key to the success of CTL industrialization in China and South Africa is the government’s strong and stable determination to improve energy security, which provides a stable top-level planning and robust policy support. The failure of CTL in United States is caused by the shift of policy attention after its energy security situation improved.

Spectroscopic study on transformations of dissolved organic matter in coal-to-liquids wastewater under integrated chemical oxidation and biological treatment process

A large amount of wastewater containing various toxic organic contaminants is produced during coal-to-liquids process. In this study, several spectroscopic methods were used to monitor the transformation of organic pollutants during an integrated chemical oxidation and biological process. The results showed that the hydrophobic acid fraction increased after Fenton oxidation, which was likely due to the production of small-molecule organic acids. Soluble microbial products were generated during biological treatment processes,which were degraded after ozonation; meanwhile, the hydrophilic base and acid components increased. Ultraviolet-visible spectroscopic analysis indicated that peaks at the absorption wavelengths of 280 and 254 nm, which are associated with aromatic substances, were detected in the raw water. The aromatic substances were gradually removed, becoming undetectable after biological aeration filter（BAF） treatment. Fourier transform infrared spectroscopy analysis revealed that the functional groups of phenols;benzene, toluene, ethylbenzene, and xylene（BTEX）; aromatic hydrocarbons; aliphatic acids;aldehydes; and esters were present in raw wastewater. The organic substances were oxidized into small molecules after Fenton treatment. Aromatic hydrocarbons were effectively removed through bioadsorption and biodegradation after BAF process.Biodegradable organic matter was reduced and finally became undetectable after anoxic–oxic treatment in combination with a membrane bioreactor. Four fluorescent components were fractionated and obtained via excitation–emission matrix parallel factor analysis（EEM-PARAFAC）. Dissolved organic matter fractionation in conjunction with EEM-PARAFAC was able to monitor more precisely the evolution of characteristic organic contaminants.

Lifecycle carbon footprint and cost assessment for coal-to-liquid coupled with carbon capture,storage,and utilization technology in China

Thecoal-to-liquidcoupledwithcarbon capture,utilization,and storage technology has the potential to reduce CO_(2)emissions,but its carbon footprint and cost assessment are still insufficient.In this paper,coal mining to oil production is taken as a life cycle to evaluate the carbon footprint and levelized costs of direct-coal-toliquid and indirect-coal-to-liquid coupled with the carbon capture utilization and storage technology under three scenarios:non capture,process capture,process and public capture throughout the life cycle.The results show that,first,the coupling carbon capture utilization and storage technology can reduce CO_(2)footprint by 28%-57%from 5.91 t CO_(2)/t:oil of direct-coal-to-liquid and 24%-49%from 7.10 t CO_(2)/t:oil of indirect-coal-to-liquid.Next,the levelized cost of direct-coal-to-liquid is 648-1027$/t of oil,whereas that of indirect-coal-to-liquid is 653-1065$/t of oil.When coupled with the carbon capture utilization and storage technology,the levelized cost of direct-coalto-liquid is 285-1364$/t of oil,compared to 1101-9793/t of oil for indirect-coal-to-liquid.Finally,sensitivity analysis shows that CO_(2)transportation distance has the greatest impact on carbon footprint,while coal price and initial investment cost significantly affect the levelized cost ofcoal-to-liquid.