Screening biorefinery pathways to biodiesel, green-diesel and propylene-glycol: A hierarchical sustainability assessment of process.

Plant design implies the best choice among a set of feedstock-to-product process pathways. Multiple sustainability performance indicators can blur the decision, and existing sustainability assessment methods usually focus only on environmental life-cycle performance and corporate metrics or solely on the gate-to-gate process. It is relevant to incorporate integrated system analysis to address sustainability comprehensively.

Sewage-water treatment with bio-energy production and carbon capture and storage.

Typical large-scale sewage-water treatments consume energy, occupy space and are unprofitable. This work evaluates a conceivable two-staged sewage-water treatment at 40,000 m/d of sewage-water with sewage-sludge (totaling 10kg/m) that becomes a profitable bioenergy producer exporting reusable water and electricity, while promoting carbon capture. The first stage comprises microbial anaerobic digesters reducing the chemical oxygen demand (COD) by 95% and producing 60%mol methane biogas.

Economic leverage affords post-combustion capture of 43% of carbon emissions: Supersonic separators for methanol hydrate inhibitor recovery from raw natural gas and CO drying.

Offshore oil/gas productions are power intensive and CO emitters from gas-fired power generation. This work investigates supersonic separator as a strategy for affording post-combustion capture backed up by cost reductions. Conventional offshore gas processing usually loses thermodynamic hydrate inhibitor methanol in processing and exported gas.

Effects of CO2 enrichment and nutrients supply intermittency on batch cultures of Isochrysis galbana.

Aiming at enhanced performance to increase economic feasibility of microalgae based processes, Isochrysis galbana was grown in three modes of cultivation: batch, intermittent fed batch and semi-continuous. The batch mode was conducted under two regimes of aeration: conventional aeration and CO2 enriched aeration (5% v/v in air). Increased biomass productivity without significant impact on lipid accumulation was observed for CO2 enriched aeration relatively to cultivation aerated with air only.