Yigang Ding

Catalytic hydroprocessing of microalgae-derived biofuels: a review

The algal biofuel technology has been accelerated greatly during the last decade. Microalgae can be processed into a broad spectrum of biofuel precursors, which mainly include crude algal oil recovered by extraction and bio-crude oils produced from hydrothermal liquefaction and pyrolysis processes. Due to the high protein content in algal species and the limitations of conversion technologies, these biofuel precursors require the further catalytic removal of heteroatoms such as oxygen, nitrogen, and sulfur, being upgraded to biofuels like green diesel and aviation fuel. This article reviews the state-of-the-art in the hydroprocessing of microalgae-based biofuels, as well as the catalyst development and the effect of process parameters on hydrotreated algal fuels. Hydroprocessing of algal fuels is a new and challenging task, and still underdeveloped. For the long term, an ideal catalyst for this process should possess the following characteristics: high activities towards deoxygenation and denitrogenation, strong resistance to poisons, minimized leaching problems and coke formation, and an economically sound preparation process.

The pyrolysis of duckweed over a solid base catalyst: Py-GC/MS and TGA analysis

ABSTRACT The possibility of using the solid base as the pyrolysis catalyst to synthesize chemicals from duckweed (Lemna minor) was explored. Thermogravimetric analyses indicated that the conversion of duckweed in slow pyrolysis was approximately 60 wt%. Direct pyrolysis of duckweed could form various hydrocarbons and precursors for industrious products. When pyrolyzing this species with the solid base catalyst, new chemicals such as 3-methyl-butanal, cyclobutanol, 2-methyl-1H-pyrrole, ethylbenzene, 2-pyrrolidinone, and 4-ethyl-phenol were synthesized. The results indicated that the application of the solid base in pyrolysis mainly enhanced the alkyl substitution reactions and could direct complex pyrolysis reactions to preferred products.

Recent Developments in Commercial Processes for Refining Bio-Feedstocks to Renewable Diesel

The process technologies for conversion of bio-feedstocks such as vegetable oils, animal fats, and algal oil into renewable diesel have been developed and commercialized during the last decade. The global annual production capacity of renewable diesel is approaching to 5.5 million tons per year. The refining process generally includes pretreatment of the renewable feedstock to remove impurities, hydroprocessing and isomerization to produce hydrocarbons, and distillation to produce a fuel suitable for use as diesel or jet fuel. This article reviews recent development in the commercial production of renewable diesel, pretreatment technologies, chemistry of deoxygenation and cracking of triglycerides, the effect of reaction parameters on the relative activities of different reaction pathways, catalyst development, and the technical details of commercial processes for refining bio-feedstocks.