Hydrocarbon bio-jet fuel from bioconversion of poplar biomass: life cycle assessment

BACKGROUND

Bio-jet fuels compatible with current aviation infrastructure are needed as an alternative to petroleum-based jet fuel to lower greenhouse gas emissions and reduce dependence on fossil fuels. Cradle to grave life cycle analysis is used to investigate the global warming potential and fossil fuel use of converting poplar biomass to drop-in bio-jet fuel via a novel bioconversion platform. Unique to the biorefinery designs in this research is an acetogen fermentation step. Following dilute acid pretreatment and enzymatic hydrolysis, poplar biomass is fermented to acetic acid and then distilled, hydroprocessed, and oligomerized to jet fuel. Natural gas steam reforming and lignin gasification are proposed to meet hydrogen demands at the biorefineries. Separate well to wake simulations are performed using the hydrogen production processes to obtain life cycle data. Both biorefinery designs are assessed using natural gas and hog fuel to meet excess heat demands.

RESULTS

Global warming potential of the natural gas steam reforming and lignin gasification bio-jet fuel scenarios range from CO2 equivalences of 60 to 66 and 32 to 73 g MJ(-1), respectively. Fossil fuel usage of the natural gas steam reforming and lignin gasification bio-jet fuel scenarios range from 0.78 to 0.84 and 0.71 to 1.0 MJ MJ(-1), respectively. Lower values for each impact category result from using hog fuel to meet excess heat/steam demands. Higher values result from using natural gas to meet the excess heat demands.

CONCLUSION

Bio-jet fuels produced from the bioconversion of poplar biomass reduce the global warming potential and fossil fuel use compared with petroleum-based jet fuel. Production of hydrogen is identified as a major source of greenhouse gas emissions and fossil fuel use in both the natural gas steam reforming and lignin gasification bio-jet simulations. Using hog fuel instead of natural gas to meet heat demands can help lower the global warming potential and fossil fuel use at the biorefineries.

α-Fe2O3 nanotubes-reduced graphene oxide composites as synergistic electrochemical capacitor materials

We present a facile approach for the fabrication of a nanocomposite comprising α-Fe(2)O(3) nanotubes (NTs) anchored on reduced graphene oxide (rGO) for electrochemical capacitors (ECs). The hollow tubular structure of the α-Fe(2)O(3) NTs presents a high surface area for reaction, while the incorporation of rGO provides an efficient two-dimensional conductive pathway to allow fast, reversible redox reaction. As a result, the nanocomposite materials exhibit a specific capacitance which is remarkably higher (~7 times) than α-Fe(2)O(3) NTs alone. In addition, the nanocomposites show excellent cycling life and large negative potential window. These findings suggest that such nanocomposites are a promising candidate as negative electrodes in asymmetrical capacitors with neutral electrolytes.

Dodecanethiol-Protected Copper/Silver Bimetallic Nanoclusters and Their Surface Properties

Dodecanethiol-protected copper/silver bimetallic nanoclusters were prepared by a liquid-phase method using different copper to silver feed ratios. The morphology and size of the prepared nanoclusters were analyzed with X-ray diffraction (XRD) and transmission electron microscopy (TEM), while their spectroscopic and surface properties were characterized by infrared (IR) and X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), and 13C cross-polarization magic angle spinning NMR (13C CPMAS NMR). TEM analysis indicated that all the bimetallic clusters prepared are approximately 4-6 nm in size. On the other hand, the results of XRD, XPS, and Fourier transform infrared (FTIR) spectroscopy suggested that the surfaces of the alloy nanoclusters are mostly enriched with the less noble metal copper atoms. This surface enrichment of copper may be attributed to a galvanic exchange process during preparation, and the extent of enrichment is directly related to the copper feed ratio used. Interestingly, DSC studies showed two melting transitions in some of these alloy samples, suggesting different packing behavior of the dodecanethiol chains onto the heterogeneously intercalated silver- and copper-rich surfaces.

Contralateral tension pneumothorax following unilateral chest tube drainage of bilateral pneumothoraces in a heart-lung transplant patient

Bilateral pneumothoraces can result from unilateral air leak after heart-lung transplantation. The recommended initial management of such patients is insertion of a unilateral chest tube. We report a patient who developed bilateral pneumothoraces after undergoing transbronchial biopsies 2 years after a heart-lung transplant. The unilateral chest tube failed to drain the contralateral pneumothorax and a tension pneumothorax developed. The advocated approach should be used with caution.

A case of human melioidosis originating in south-west Western Australia

OBJECTIVE

To report the first human case of autochthonous melioidosis in temperate Australia (latitude 31 degrees 10'S) and to describe the extent of the presence of the causative agent, Pseudomonas pseudomallei, in southwest Western Australia.

CLINICAL FEATURES

A 45-year-old man living on a hobby farm was admitted to hospital for investigation of lung lesions, weight loss and low grade fevers. P. pseudomallei was cultured from material from an aspiration biopsy of a mediastinal mass.

INTERVENTION AND OUTCOME

The patient was successfully treated with a regimen of ceftazidime and trimethoprim-sulfamethoxazole. A review of epidemiological data showed that, since 1967, P. pseudomallei has been cultured from animals and soil in a region 50-250 km north-west of Perth, Western Australia, and that pockets of endemicity are found in the districts of Toodyay (where our patient's farm was), Chittering, Ballidu, Gidgegannup, Badgingarra, and Wongan Hills.

CONCLUSION

The persistence of the bacterium in animals and soil in south-west Western Australia demonstrates abundantly that P. pseudomallei can exist opportunely beyond its traditional tropical habitat. It is likely that there will be further clinical cases of melioidosis originating in this region, and that the boundaries of endemicity in Australia will expand further.

Percutaneous aspiration lung biopsy

Percutaneous needle aspiration lung biopsy is reviewed. Its method and place in the investigation of lung lesions is described and re-emphasized. It is a safe, cheap, quick and simple way to achieve a definitive diagnosis. The diagnostic accuracy is high and the complication rate low. The paper strongly advocates wider usage of this very useful investigative modality.

Ossification of the posterior longitudinal ligament of the spine

"The Japanese disease" or ossification of the posterior longitudinal ligament of the cervical spine was initially thought to affect only the Japanese people. Non-Japanese Asian and Caucasian cases have been reported but appear to be exceedingly rare. The reason is unknown. Although the disease appears to be generally benign, it can cause a myelopathy. We present here 16 non-Japanese patients in Singapore who were found to have ossification of the posterior longitudinal ligament in the cervical, thoracic and lumbar spine.

The chest X-ray in antiglomerular basement membrane antibody disease (Goodpasture's syndrome)

The chest radiographs of 25 patients with proven antiglomerular basement membrane antibody disease (Goodpasture's syndrome) were analysed. All except two of the patients had pulmonary haemorrhage at some stage of their disease. Altogether there were 39 episodes of pulmonary haemorrhage, 25 being relapses. During seven episodes the chest radiograph was normal. Relapses of pulmonary haemorrhage never occurred in isolation but were usually associated with infection (not necessarily a chest infection) or occasionally fluid overload. Conversely fluid overload or infection were always associated with pulmonary haemorrhage provided there were high or rising titres of circulating antibodies at the time. Therefore in a patient with antiglomerular basement membrane antibody disease, the presence of shadowing in the lung fields on the chest radiograph almost invariably means the patient has pulmonary haemorrhage whether or not pulmonary oedema or a chest infection are present. Limitation of shadowing by a fissure, loss of major portions of the diaphragmatic or cardiac silhouette, involvement of the lung apex or costophrenic angles suggest an underlying chest infection. Septal lines suggest fluid overload. Pleural effusions are seen with chest infections and fluid overload. The carbon monoxide uptake (KCO) was invariably high in the presence of pulmonary haemorrhage even if the chest radiograph was normal. A combined use of KCO and chest radiographs is the best method of monitoring lung disease in these patients.

Percutaneous aspiration biopsy of malignant lung lesions using the Chiba needle. An initial experience

The fine gauge Chiba needle was evaluated in percutaneous aspiration biopsy in 20 patients with suspected malignant lung neoplasm. Adequate aspirate can be obtained with one biopsy. A confident cytological diagnosis of malignancy was made in 19 out of 20 patients. Most of the patients were elderly. Nine patients developed pneumothoraces which were small and asymptomatic. The needle is easy to handle and very acceptable to patients. This needle therefore appears to be very suitable for percutaneous aspiration biopsy of lung neoplasms and possibly other non-neoplastic lesions too. It promises to supersede the larger aspiration needles currently in use.

Interstitial gastric and duodenal emphysema

A 31-year-old woman developed combined interstitial gastric and duodenal emphysema associated with acute dilatation of the stomach and duodenum following an asthmatic attack. The literature is reviewed.