http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Muhammad Kashif Iqbal Khan,Abid Aslam Maan,Rana Muhammad Aadil,Akmal Nazir,Masood Sadiq Butt,Muhammad Imtiaz Rashid,Muhammad Inam Afzal 한국식품과학회 2020 Food Science and Biotechnology Vol.29 No.4
Onion and ginger are rich sources of bioactive compounds which are lost during conventional drying process. The present study was designed to optimize the novel Microwave Assisted Drying and Extraction technique (MADE) for simultaneous drying and extraction/recovery of bioactive compounds from model food products. The time required for drying of samples was 11 (onion) and 16 (ginger) minutes with recovery yield of 87% (onion) and 85% (ginger). The drying time was reduced to 100 times compared to hot air drying and moisture ratio of dried samples was best described by Midilli model. The diffusivities of onion and ginger slices were 1.27 e-11 and 1.43 e-11 m2/s, respectively. Moreover, microwave-based extraction was compared with conventional one. The results of antioxidant activity and total phenolic contents of condensates obtained through MADE were higher compared to conventional method. In short, MADE exhibited better yield of extraction and drying properties compared to conventional methods.
Conversion of petroleum emulsion into light fraction-rich upgraded oil in supercritical methanol
Khan, Muhammad Kashif,Kwek, Winarto,Kim, Jaehoon Elsevier 2018 Fuel Vol.218 No.-
<P><B>Abstract</B></P> <P>Unconventional crude oil extraction, transportation, and downstream refining have encountered a huge formation of petroleum emulsion (or rag layer), which causes serious problems such as equipment corrosion, loss of crude oil, and catalyst poisoning. In addition, if not treated properly, the rag layer engenders toxic and hazardous effects on the environment and living organisms. In this study, we developed a supercritical methanol (scMeOH) route to convert the petroleum emulsions into light fraction-rich upgraded oil with low impurities. Several process variables were investigated, including temperature (350–400 °C), rag layer concentration (16.7–100 wt%), and reaction time (30–90 min). At 400 °C, 35 MPa, 16.7 wt%, and 90 min, a high recoverable oil yield (76.7 wt%) was achieved. In addition, the naphtha-to-diesel fractions increased significantly from 6.0 (rag layer) to 42.0 wt% (upgraded oil), the acidity in terms of total acid number (TAN) was reduced by up to 91.5% from 58.7 (rag layer) to 5.0 mg-KOH/g-oil (upgraded oil), and the heteroatoms (O, N, S) and metallic impurities (Ca, Ni, V, Fe) were reduced significantly in the upgraded oil. A model compound study revealed that esterification is the major deacidification pathway for TAN reduction. The rag layer conversion in scMeOH was compared with those in subcritical water (without adding additional methanol or water) and in supercritical water (scH<SUB>2</SUB>O). Asphaltenes, Ni, and N were completely removed from the toxic rag layer in the presence of scMeOH as compared to scH<SUB>2</SUB>O treatment, which makes it more suitable for upgrading.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Recalcitrant petroleum emulsion was demulsified completely in supercritical methanol. </LI> <LI> Almost complete removal of asphaltene, Ni and V at 400 °C and 35 MPa. </LI> <LI> Naphtha to diesel range fractions increased from 6 to 42 wt%. </LI> <LI> More than 90% toxic naphthenic acids were removed. </LI> <LI> Esterification was major reaction pathway in deacidification of model compounds. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Efficient oil recovery from highly stable toxic oily sludge using supercritical water
Khan, Muhammad Kashif,Cahyadi, Handi Setiadi,Kim, Sung-Min,Kim, Jaehoon Elsevier 2019 Fuel Vol.235 No.-
<P><B>Abstract</B></P> <P>One of the main challenges in crude oil extraction and refining is the formation of highly toxic intractable petroleum emulsions (oily sludge). Herein, the simultaneous demulsification and recovery of oil with low impurity content, trapped in petroleum emulsions, was investigated using supercritical water (scH<SUB>2</SUB>O). Various parameters, including temperature (350–400 °C), pressure (25–35 MPa), emulsion concentration (10–100 wt%), and reaction time (30–120 min) were explored to establish the optimized conditions. At 400 °C, the asphaltene content (23.7–3.4 wt%) and total acid number (15.4–2.8 mg-KOH/g-oil) decreased significantly, while the naphtha-to-diesel fraction increased from 9 to 21 wt%. These results indicated effective cracking of the toxic interfacially active species to form their non-toxic, non-interfacially active counterparts. By removing the interfacially active compounds that stabilize the petroleum emulsion, clear oil-water separation was achieved after conversion in scH<SUB>2</SUB>O, thereby facilitating the recovery of the upgraded oil. Additionally, heteroatoms and metallic impurities in the upgraded oil were significantly reduced [reduction efficiencies: 79% (V), 69% (Ni), 99% (Ca), 23% (S), 82% (N)]. Finally, plausible reaction mechanisms for the removal of interfacially active compounds were discussed using model compound reactions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Complete demulsification of toxic oily sludge by non-catalytic supercritical water. </LI> <LI> Efficient oil recovery of 75–80 wt% with negligible coke and gas formation. </LI> <LI> Asphaltenes, nitrogen and residue reduction were 90, 82 and 68% respectively at 400 °C. </LI> <LI> Acidity and heavy metals were sufficiently reduced. </LI> <LI> Alkyl-CO<SUB>2</SUB> and Aryl-CO<SUB>2</SUB> bond scissions are major pathways for deacidification. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Upgrading Heavy Crude Oils and Extra Heavy Fractions in Supercritical Methanol
Khan, Muhammad Kashif,Kwek, Winarto,Kim, Jaehoon ACS AMERICAN CHEMICAL SOCIETY 2017 ENERGY AND FUELS Vol.31 No.11
<P>Herein, we report a method of upgrading unconventional crude oils and extra heavy fractions using supercritical methanol (scMeOH) and compare it to supercritical water (scH<SUB>2</SUB>O)-based and pyrolytic upgrading. The yields and properties of upgraded oil are explored as functions of operating parameters (temperature, pressure, and concentration) and feedstocks for high-acid crude oils (Laguna and Bachaquero-13), a heavy crude oil (Rubiales), and a vacuum tower bottom (VTB). As a result, scMeOH upgrading of unconventional crude oils at 400 °C and 30 MPa effectively reduced their asphaltene content to ∼0 wt % and increased that of naphtha–diesel fractions to 30–40 wt %. Conversely, a considerable amount of asphaltenes (8.8–10.0 wt %) was present in oil upgraded using scH<SUB>2</SUB>O and pyrolysis. Additionally, scMeOH upgrading resulted in a more effective reduction of the total acid number (TAN) of high-acid crude oils (<0.5 mg of KOH/g of oil) compared to values achieved by scH<SUB>2</SUB>O and pyrolysis methods. Finally, scMeOH treatment significantly reduced the metal (Ni, V, and Fe) content of the upgraded oil. The effective asphaltene content and TAN reduction realized in scMeOH was attributed to its hydrogen donation and esterification ability, with plausible mechanisms of scMeOH, scH<SUB>2</SUB>O, and pyrolytic upgrading presented and discussed in detail.</P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ef7b02524'>ACS Electronic Supporting Info</A></P>
Aslam, Muhammad,Ahmad, Rizwan,Yasin, Muhammad,Khan, Asim Laeeq,Shahid, Muhammad Kashif,Hossain, Shakhawat,Khan, Zakir,Jamil, Farrukh,Rafiq, Sikander,Bilad, Muhammad Roil,Kim, Jeonghwan,Kumar, Gopalakr Elsevier 2018 Bioresource technology Vol.269 No.-
<P><B>Abstract</B></P> <P>Biohydrogen as one of the most appealing energy vector for the future represents attractive avenue in alternative energy research. Recently, variety of biohydrogen production pathways has been suggested to improve the key features of the process. Nevertheless, researches are still needed to overcome remaining barriers to practical applications such as low yields and production rates. Considering practicality aspects, this review emphasized on anaerobic membrane bioreactors (AnMBRs) for biological hydrogen production. Recent advances and emerging issues associated with biohydrogen generation in AnMBR technology are critically discussed. Several techniques are highlighted that are aimed at overcoming these barriers. Moreover, environmental and economical potentials along with future research perspectives are addressed to drive biohydrogen technology towards practicality and economical-feasibility.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Anaerobic membrane bioreactor technology for biohydrogen production is overviewed. </LI> <LI> Enhancement of biohydrogen yield and generation rates via various strategies is discussed. </LI> <LI> Techno-economic and environmental impacts of this approach are addressed. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Saad Ullah Khan,Khawaja Khalid Mehmood,Soon-Jeong Lee,Zunaib Maqsood Haider,Muhammad Kashif Rafique,Chul-Hwan Kim 한국조명·전기설비학회 2017 조명·전기설비학회논문지 Vol.31 No.9
Secure and continuous electric vehicle (EV) charging operation is a key concern for the safety of EVs and their reliable integration with the power grid. During a lightning incident on the distribution network, the security of integrated EVs is threatened. Lightning overvoltages can be damaging for the EVs, resulting in huge repair costs. Thus, it is necessary that the feeder is provided with lightning protection for the safe integration of EVs. This paper has analyzed direct lightning overvoltages on IEEE 13-node distribution feeder with and without surge arrester protection. The system overvoltages are evaluated on primary distribution nodes, which are the prospective locations for EV connection. Results show the importance of lightning protection of the feeder for EV integration.