Enzymatic biodiesel synthesis in semi-pilot continuous process in near-critical carbon dioxide.

A semi-pilot continuous process (SPCP) for enzymatic biodiesel synthesis utilizing near-critical carbon dioxide (NcCO₂) as the reaction medium was developed with the aim of reducing the reaction time and alleviating the catalyst inhibition by methanol. Biodiesel synthesis was evaluated in both lab-scale and semi-pilot scale reactors (batch and continuous reactors). In a SPCP, the highest conversion (∼99.

Optimization of enzymatic biodiesel synthesis using RSM in high pressure carbon dioxide and its scale up.

Enzymatic synthesis of biodiesel by the transesterification of canola oil and methanol in high pressure carbon dioxide [HPCO(2): near-critical and supercritical carbon dioxide (NcCO(2) and ScCO(2))] was optimized using response surface methodology (RSM). RSM based on 5-level-5-factor central composite rotatable design (CCRD) was used to evaluate the effects of temperature, pressure, enzyme loading, substrate molar ratio, and time on the conversion to biodiesel by transesterification. Finally, batch reactions for biodiesel synthesis were preformed in a 100 mL and 7 L high-pressure stirred batch reactors.

A Multicenter Study of Pertussis Infection in Adults with Coughing in Korea: PCR-Based Study.

Background: Limited data on the incidence and clinical characteristics of adult pertussis infections are available in Korea.

Methods: Thirty-one hospitals and the Korean Centers for Disease Control and Prevention collaborated to investigate the incidence and clinical characteristics of pertussis infections among adults with a bothersome cough in non-outbreak, ordinary outpatient settings. Nasopharyngeal aspirates or nasopharyngeal swabs were collected for polymerase chain reaction (PCR) and culture tests.

Enzymatic coproduction of biodiesel and glycerol carbonate from soybean oil and dimethyl carbonate.

The enzymatic coproduction of biodiesel and glycerol carbonate by the transesterification of soybean oil was studied using lipase as catalyst in organic solvent. To produce biodiesel and glycerol carbonate simultaneously, experiments were designed sequentially. Enzyme screening, the molar ratio of dimethyl carbonate (DMC) to soybean oil, reaction temperature and solvent effects were investigated.

Improvement of enzymatic biodiesel production by controlled substrate feeding using silica gel in solvent free system.

A silica gel-based substrate feeding system was developed to prevent methanol inhibiting the catalyst during enzymatic biodiesel synthesis. In the system, silica gel swelled upon methanol addition and subsequently released it in a controlled manner to prevent excess methanol affecting the enzyme. Biodiesel was synthesized by the enzymatic transesterification of canola oil with methanol.

Improved high-pressure enzymatic biodiesel batch synthesis in near-critical carbon dioxide.

The enzymatic synthesis of biodiesel by a high-pressure semi-continuous process in near-critical carbon dioxide (NcCO(2)) was studied. Biodiesel synthesis was evaluated in both batch and semi-continuous systems to develop an effective process. Batch processing demonstrated the advantageous properties of NcCO(2) as an alternative reaction medium.

Effects of various pretreatments for enhanced anaerobic digestion with waste activated sludge.

The purpose of this study was to enhance the efficiency of anaerobic digestion with waste activated sludge (WAS) by batch experiments. We studied the effects of various pretreatment methods (thermal, chemical, ultrasonic and thermochemical pretreatments) on the biogas production and pollutants reduction owing to solubilization enhancement, particle size reduction, increased soluble protein, and increased soluble COD. The thermochemical pretreatment gave the best results, i.