Simulation and Analysis on Desulfurization of Biogas using Iron Oxide Particles

( Cheng-chang Lien ),( Min-wei Wang ),( Ming-hong Ke ),( Tong-bao Zhang ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

Biogas has a great potential for renewable energy, it contained with hydrogen sulfide which can cause metal equipment corrosion. Therefore the Hydrogen sulfide must be remove before uses biogas, in order to remove hydrogen sulfide in biogas that let biogas passed through the desulfurization column during field application. Inside of the desulfurization column has the certain height of iron oxide particles, Hydrogen sulfide in biogas will generates adsorption reaction on the surface of the iron oxide particles and forms iron sulfide to achieve the purpose of biogas purification. The purpose of this study uses computational fluid dynamics (CFD) numerical simulation to simulate the desulfurization column at a certain amount of biogas to obtain the pressure between the inlet and the outlet of the desulfurization column, and also obtained the airflow velocity profile inside the desulfurization column. The results of this simulation are compared with the actual measured pressure data, it shows that both have a good consistency. For further, improve the upper end of the exit of the desulfurization column to an inverted funnel shape for comparative analysis, it found that the flow in the inverted funnel at the top of the desulfurization column has obviously slowed down which means the sudden contraction (sudden unremitting). This result will provide help to improve a uniformity of the air velocity in the non-central region of the desulfurization column, in order to promote the iron oxide particles of its effective utilization of biogas desulfurization.

Regeneration of sodium bicarbonate from industrial Na-based desulfurization waste using ammonium hydroxide

이동현,윤태호,민정기,Youngchul Byun,임창용 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.122 No.-

In an effort to improve industrial waste recycling and realize zero-waste technology, we optimized theregeneration of sodium bicarbonate from desulfurization waste using aqueous ammonia. Sodium bicarbonateis essential for absorbing SO2 gas in flue gas desulfurization. Based on X-ray fluorescence analysis,desulfurization waste consists of 86.2% sodium sulfate. Rapid deposition of undesired ammonium bicarbonatein a reactor was observed at the early stages of the reaction when using ammonia gas, resulting ininsufficient yield. For further improvement, the effect of ammonia solution dosage was explored in detail. The yield/purity of sodium bicarbonate regenerated from desulfurization waste is very close to that frompure sodium sulfate, 58.2/85.9% and 56.6/91.5%, respectively. Moreover, owing to greater surface area,the as-regenerated sample showed higher desulfurization performance (97% removal rate) than commercialsodium bicarbonate (88.6%) on 200 ppm SO2 gas at a 5 g/min feeding rate.

Ultrasound Assisted Oxidative Desulfurization: A Definitive Screening Design Analysis

( Angelo Earvin Sy Choi ),( Susan Roces ),( Nathaniel Dugos ),( Meng-wei Wan ),( Hung-suck Park ) 한국폐기물자원순환학회(구 한국폐기물학회) 2016 한국폐기물자원순환학회 추계학술발표논문집 Vol.2016 No.-

The desulfurization of untreated petroleum oil is required in order to comply with stringent environmental regulations. Ultrasound-assisted oxidative desulfurization (UAOD) is an innovative technology for sulfur removal in order to avoid the environmental hazards associated with the combustion of sulfur compounds in raw diesel oil. In this study, diesel oil is treated through UAOD. The effects of ultrasound time (6-30 min), amplitude (20-60%), phase transfer agent (100-500mg), catalyst dosage (10-500mg), H₂O₂ concentration (30-50%v/v), organic to aqueous phase (OP:AP) ratio (50:50-90:10) and reaction temperature (30-70℃) were examined. The screening analysis used is the definitive screening design that statistically determines the parameters that have a significant effect on the oxidation of diesel oil. Results indicate that significant factors (p-value < 0.5) where ultrasound time, amplitude, catalyst dosage and reaction temperature; while the phase transfer agent, H₂O₂ concentration and OP:AP ratio were insignificant (p-value > 0.5) on the response of sulfur conversion in the untreated diesel oil. This study concludes that the essential factors to achieve deep desulfurization in diesel oil include ultrasound time, amplitude, H₂O₂ concentration and reaction temperature which are key factors in the oxidation of sulfur compounds to achieve low sulfur containing diesel oil.

Ordered Mesoporous WO3/KIT-6 Catalyst for Oxidative Desulfurization: Application to the Removal of Dibenzothiophene

홍경희,이정화,이성빈,박진서,김지만 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.0

Mesoporous KIT-6 supported WO3 catalysts (with various WO3 loadings of 5, 10, 15and 20wt%) were synthesized by incipient impregnation method and used as the catalysts for oxidative desulfurization of model oil. The materials were well-characterized by X-ray diffraction, N2-adsorption, Scanning electron microscope, Transmission electron microscopy, H2-TPR and Raman spectroscopy. The results show that the WO3/KIT-6 catalyst with a WO3 content up to 10wt% can well dispersed on the support of mesoporous KIT-6, and from 15wt%, crystalline WO3 was generated. The application of these catalysts to the oxidative desulfurization (ODS) of aromatic sulfur compounds with H2O2 was reported. The effects of reaction temperature, catalyst amount, and H2O2/S ratio on the desulfurization of DBT over 10wt% WO3/KIT-6 were studied in detail. And when the temperature increased to 70°C, treatment of BT, DBT, 4,6-DMDBT with 10wt% WO3/KIT-6 showed 100% removal of sulfur compounds in 2h.

모사 Spray Type배연탈황설비를이용한소성패각슬러리의 SO₂흡수능평가:석회석과의 비교연구

김석휘(Seok-Hwi Kim),홍범의(Bum-Uh Hong),이진원(Jin-Won Lee),차왕석(Wang-Seok Cha),김강주(Kangjoo Kim),문보경(Bo-Kyung Moon) 대한자원환경지질학회 2019 자원환경지질 Vol.52 No.2

국내에서는 연간 약 30만 톤 내외의 굴패각이 발생되고 있어, 이를 대규모로 활용할 수 있는 적절한 방안이 요구되고 있다. CaCO3가 주성분인 굴패각을 탈황재료로 사용하는 연구들이 많이 진행되어 왔으나, 지금까지는 주로 건식탈황을 대상으로 한 것이었다. 본 연구에서는 굴패각을 소성하여 습식탈황재료로 활용하는 가능성에 대하여 고찰하였다. 이를 위하여 습식배연탈황공정의 하나인 spray type 방식의 모사탈황장치를 제작하여 소성 굴패각의 탈황특성을 석회석과 비교하였다. 연구결과, 소성 굴패각은 석회석이나 소성하지 않은 굴패각에 비하여 우수한 SO₂ 흡수능을 보였다. 이는 굴패각이 소성 및 수화반응을 통해 상대적으로 반응성이 높은 형태(Ca(OH)2)로 전환되었기 때문이다. 이로 인하여 반응잔류물 중에 석고(CaSO4·2H2O)의 함량이 다른 경우에 비하여 높게 나타났다. 본 연구의 연속탈황실험에서는 소성 굴패각이 석회석에 비하여 큰 pH 변동폭을 보였으며, 석회석과 소성 굴패각을 혼합하여 수행된 탈황실험에서도 소성 굴패각의 혼합비율이 증가됨에 따라 pH변동폭이 커지는 결과를 보였다. 이러한 현상은 소성 굴패각의 SO₂ 흡수 반응성이 큰 것을 잘 보여주는 것이다. 본 연구결과는 소성 굴패각을 습식탈황에 이용할 경우 탈황효율을 크게 향상시킬 수 있음도 보여준다. About 300,000 tones of oyster shell are annually produced in Korea and, thus, a massive recycling plan is required. Many desulfurizing studies using oyster shells with chemical composition of CaCO3 have been performed so far; however, most of them have focused on dry desulfurization. This study investigates the possibility of using oyster shells for wet desulfurization after calcination. For this, a simulated wet desulfurization facility of spray type was devised and compared the SOx-stripping characteristics of calcined oyster shell with those of limestone. The calcined oyster shell slurry indicate a better desulfurizability than the slurries of raw shell or limestone because the oyster shell transformed to a more reactive phase (Ca(OH)2) by the calcination and hydration. Because of this reason, when the calcined oyster shell slurries were used, the reaction residue showed the higher gypsum (CaSO4·2H2O) contents than any other cases. In the continuous desulfurization experiments, calcined oyster shell slurry showed a wider pH variation than limestone or raw oyster shell slurries, another clear indication of high reactivity of calcined oyster shells for SO₂ absorption. Our study also shows that the efficiency of wet desulfurization can be improved by the use of calcined oyster shells.

천연제올라이트를 지지체로 사용한 고온건식 아연계 탈황제의 반응특성 연구

박노국,정용길,이종대,이태진,김재창 한국화학공학회 2003 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.41 No.5

고온건식 탈황제의 지지체로 알루미나와 천연제올라이트를 사용하여 아연계 탈황제를 제조하였으며 성능을 조사하였다. 두 가지 탈황제의 반응특성실험은 480℃/580℃(황화/재생온도)에서 칸 밸런스와 고정층 반응장치로 반응속도와 황수용능력을 비교하였으며 내마모 실험장치를 이용하여 탈황제의 내마모도를 조사하였다. 두 탈황제의 성능 실험결과 천연제올라이트를 지지체로 사용한 탈황제의 초기 황화반응속도가 알루미나를 지지체로 사용한 탈황제보다 빨라졌으며, 10 cycle에서 황수용능력이 20 gS/100 g sorbent 이상 유지되었다. 내마모성은 AI(마모지표)값이 14.7%정도였다. 본 연구에서는 천연제올라이트의 고온건식 탈황제의 지지체로 적용 가능성을 확인하였다. Two types of zinc-based sorbents using alumina and natural zeolite as the supports for hot-gas desulfurization were prepared, and investigated their desulfurization capability. Their reaction rate and sulfur capacity were compared by Cahn balance and over the fixed bed reactor system at 480℃/580℃ (sulfidation/regeneration). The attrition resistance was measured by ASTM methd. Thc initial sulfidation rate of ZnO/natural zeolite sorbent was higher than that of ZnO/alumina, and the sulfur capacity of ZnO/natural zeolite sorbent was maintained above 20 gS/l00 g sorbent for 10 cycles. A attrition index was 14.7%. The use of natural zeolite as a support of sorbents may be possible for hot gas desulfurization.

초저황 디젤 생산을 위한 탈황 기술 동향

박조용 ( Jo Yong Park ),김재곤 ( Jae Kon Kim ),임의순 ( Eui Soon Yim ),정충섭 ( Choong Sub Jung ) 한국유화학회 2013 한국응용과학기술학회지 Vol.30 No.3

Sulfur content of diesel fuel has been cut down to under 10 ppm ULSD (ultra low sulfur diesel) level by environmental regulation with the aim of reducing exhaust emissions. This review discusses the methods and principles of sulfur reduction in diesel and presents an overview of new approaches for ultra-deep desulfurization. The deep HDS (hydrodesulfurization) problems of diesel streams is exacerbated by the inhibiting effect of co-existing aromatics, nitrogen compounds and H2S. The new approaches to deep desulfurization includes non-HDS type processing schemes such as adsorptive, extractive and oxidative desulfurization.

폐타이어 분말의 Acidithiobacillus 종에 의한 탈황 메커니즘

박세호(Se-Ho Park),이민지(Minji Lee),김동학(Donghak Kim),이재열(Jae-Yeul Lee),양선아(Seun-Ah Yang),방대석(Daesuk Bang),지광환(Kwang-Hwan Jhee) 한국고분자학회 2015 폴리머 Vol.39 No.4

폐타이어(WTR)는 안정한 가교결합을 하고 있어 자연 상태에서 변형되기 어려워 환경 문제를 일으킨다. 이에 우리는 Acidithiobacillus 종을 이용하여 폐타이어의 분말 크기에 따른 생물학적 탈황 메커니즘을 연구하였다. 본 연구에서는 FTIR-ATR과 XPS를 사용하여 탈황 전후의 폐타이어 표면의 화학구조 및 화학적 결합을 측정하였다. FTIR-ATR 분석 결과, C=C 결합(1540 cm<SUP>-1</SUP>)에서의 값이 탈황 후 감소하였으며, XPS 분석으로, 탈황된 폐타이어(DWTR)의 표면에서 S-O, S-S, S-C 결합이 감소함을 확인하였다. 또한 DTNB 정량법과 황산 이온의 양을 측정함으로써 WTR과 DWTR의 탈황을 확인하였다. 결론적으로 Acidithiobacillus 종들은 WTR 표면의 가교결합인 S-S 결합을 파괴하여 sulfoxide, sulfone, SO4<SUP>2-</SUP> 이온의 형태로 변화시킴을 확인하였다. Waste tire rubber (WTR) is hard to transform naturally because of the stable crosslinked structure of rubber material, resulting in environmental problems. Here, we investigated the biological desulfurization mechanism of WTR by Acidithiobacillus strains (Acidithiobacillus thioxidans and Acidithiobacillus ferrooxidans) by the size of crushed WTR. The surface chemical groups of desulfurizated waste tire rubber (DWTR) were analyzed by FTIR-ATR and XPS. FTIRATR data exhibited C=C bonds (1540 cm<SUP>-1</SUP>) decreased after desulfurization. XPS data showed S-O, S-S and S-C bonds were remarkably decreased on the surface of DWTR. Also, we confirmed desulfurization between WTR and DWTR by DTNB assay and SO4<SUP>2-</SUP> ion measurement. Taken together, Acidithiobacillus species break the crosslinked disulfide bonding on the surface of WTR, resulting in sulfoxide, sulfone, and sulfate ions.

Oxidative desulfurization and denitrogenation of fuels using metal-organic framework-based/-derived catalysts

Bhadra, Biswa Nath,Jhung, Sung Hwa Elsevier 2019 Applied Catalysis B Vol.259 No.-

<P><B>Abstract</B></P> <P>Removal of sulfur- and nitrogen-containing compounds (SCCs and NCCs) from commercial fuel is very important since those impurities can cause various problems including catalyst deactivation and acid rain. Because of the limitations of the conventional refinery methods, development of a new method such as oxidative desulfurization (ODS) is highly desirable. Metal-organic frameworks (MOFs)-based and MOF-derived nanohybrid materials were suggested as a good catalyst for ODS of fuels. Moreover, removal of NCCs via oxidation with MOF-derived catalyst was also reported even though the technique is just emerging. Therefore, it is required to analyze the reported results; and more importantly to suggest a new research direction; and finally, to estimate the possibility of new desulfurization/denitrogenation technology that might replace/compensate studied technologies. This review might be quite beneficial not only to accumulate or understand the reported results but also to develop new efficient catalysts for the probable commercialization of the ODS/ODN technology.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Oxidative purification of fuel with MOFs or MOF-derived materials was summarized. </LI> <LI> Oxidative catalysis to remove S- and N-compounds from fuel was analyzed. </LI> <LI> The mechanism and limit/possibility of the catalysis with those catalysts were summarized. </LI> <LI> The prospect and future research direction on the field were summarized/suggested. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

석유 코크스에 함유된 황 성분의 직접 탈황: 용매 추출 및 고온 열처리 비교

박노국,송유나,부진호,이승우,김민규,이승종,윤용승 한국에너지기후변화학회 2022 에너지기후변화학회지 Vol.17 No.2

In this study, the possibility of direct desulfurization technology as a pretreatment technology to reduce theconcentration of sulfur compounds contained in syngas produced from the gasification of petroleum coke wasexperimentally investigated. High-temperature thermal treatment and solvent extraction were applied as directdesulfurization techniques for petroleum cokes. The weight changes due to volatilization of free sulfur above 250 °C wasconfirmed by TGA analysis. When the thermal treatment of petroleum coke powder was performed in the range of250-330 °C, sulfur volatilization with high yield above 330 °C was confirmed by SEM / EDX analysis. In addition, it wasconfirmed by UV-Visible adsorption spectrum and FT-IR analysis that organic sulfur contained in petroleum coke wasextracted with using ethanol, acetone, and polyethylene glycol as solvents. Although the effect of direct desulfurizationis not high by thermal treatment and solvent extraction, it was considered to be effective as a pretreatment method toreduce the concentration load of sulfur compound gases in syngas produced from petroleum cokes derived gasification. In the future, it was expected to contribute to the expansion of mass hydrogen production technology by developing apretreatment process technology to reduce sulfur content in petroleum coke by direct desulfurization.