scholarly journals Sulfur Recovery from Syngas in Pulp Mills with Integrated Black Liquor Gasification

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1173
Author(s):  
Michal Hruška ◽  
Miroslav Variny ◽  
Juma Haydary ◽  
Ján Janošovský

Research Highlights: As to fill the current knowledge gap and to deliver important findings to the scientific community, efficient sulfur recovery from black liquor gasifier syngas, comprising both gas cleaning and returning sulfur to the pulping process, was modeled and assessed from a techno-economic viewpoint. This manuscript proves that the associated investment and operational costs cannot be neglected and that they impact the black liquor gasification feasibility significantly. To prove its gasification as a sustainable and more efficient processing route over its combustion in recovery boilers, a substantial process efficiency improvement and operating costs reduction must be targeted in future research. Background and Objectives: Sulfur compounds found in black liquor partly turn into hydrogen sulfide during gasification and exit the gasifier in the syngas. Their efficient recovery in their sulfidic form to the pulping process is of utmost importance. Current studies focus on black liquor gasifier syngas desulfurization only. Materials and Methods: A mathematical model of two H2S absorption units from a 66.7 tDS/h (1600 tons dry solids per day) black liquor gasification process to 20 ppm H2S content in cleaned syngas using either white liquor plus NaOH or N-methyldiethanolamine (MDEA) was created using the Aspen Plus simulation software. Results: The results show that CO2 co-absorption significantly increases the lime kiln load: +20% in the MDEA alternative and +100% in the other one. The MDEA alternative requires almost the same investment costs but by around USD 9.7 million (>50%) lower annual operating costs compared to the other one. Economic evaluation was based on the assumed discount rate of 5% and on the expected plant operation time of 25 years. The estimated total investment cost of the whole plant is around USD 170 million for both alternatives. The whole plant including this alternative exhibits a positive net present value (over USD 19 million), an internal rate of return of 5% and a profitability index of 1.12, whereas that with the other alternative is economically infeasible. Conclusions: The MDEA-based syngas cleaning technology represents a more efficient and economically feasible option of sulfur recovery. A major drawback of both modeled syngas cleaning technologies is that their estimated annual operating costs significantly reduce the expected profit margin of gasification over the traditional black liquor combustion in a recovery boiler. Syngas cleaning and sulfur recovery have to be further optimized to reach a significant cut down in operational costs to improve the economic feasibility of black liquor gasification.

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Haikal Rahman

This study is specifically aims to elaborate  on the  economic valuation  that  consists of: (1) Investment costs and (2) Operating  Costs of the alternative  waste  management technology which can be applied to the final processing of Municipalities Solid Waste. The results of the simulation shows that the Biodrying with the combination of Incenerator or Gasification is the technology that has the least operational costs with an average of 10.907 million Euro per year of its operational costs. On the other hand the Aerobic MBT (Mechanical Biological Treatment) without the production of RDF (refuse Derivative Fuel) technology is a technology that requires the highest operational costs with an average of 15,808 million Euro per year. In terms of the initial investment costs both Biological Treatment technology has the lower value compare to the two Thermal Treatment technologies.


Author(s):  
Bruno Henrique S. Amorim ◽  
Luis Fernando G. Pires ◽  
Ivan Menezes ◽  
António Filipe F. Montalvão ◽  
Fábio M. Limeira

The use of drag reduction agents (DRA) can be a decisive factor in determining the technical and economic feasibility of new pipelines projects, meeting the demands not foreseen and seasonality accommodation without large investments in infrastructure. Knowing the friction reduction mechanism and its impact on the operating procedure of existing products is essential in order to have the guarantee of the benefit for your application. Most of the works published report field experiences obtained from its application, seeking to determine the influence that internal and external factors have on the polymer. Knowing these effects is essential for better application performance. However, few authors have sought to identify the best way to operate an existing pipeline with DRA, with either an increase in capacity or an energy reduction. Operationally, the use of drag reducing agents may decrease the currently used arrangement of pumps, or even the complete shutdown of a pumping station. In this context, the use of drag reducers may be a suitable solution for decreasing power consumption in fluid transport pipelines of petroleum and derivatives. This paper presents a case study of the application of drag reducing agents in a Brazilian high-energy pipeline. It features five intermediate pumping stations and three withdrawal points along its nearly one thousand kilometer stretch. With the aid of a computer simulation software, it is proposed a methodology to evaluate the best application condition, minimizing pump costs, polymer volume and meeting the scheduled demand of the month. This methodology first sought to validate the computational model of the pipeline. It was made a historical survey and inserted into the simulator, in order to reproduce faithfully a monthly operation. A sensitivity analysis is performed to determine which pump stations are most relevant. It was established an initial concentration of polymer to be injected in the sending refinery, aiming the reduction of arrangement or total shutdown of the subsequent station and keeping volume delivered on all points. The other bases remain working according to the operation of the month. This procedure is then repeated for the other bases, resulting in a combined and continuous injection, minimizing the operating costs. An economic evaluation is finally performed to quantify the benefits of this application. A reduction in energy consumption of 49% was noticed, and considering the costs with DRA, the monthly movement had a 35% drop in the total costs of operation.


Liquidity ◽  
2016 ◽  
Vol 5 (1) ◽  
pp. 53-64
Author(s):  
Yumniati Agustina

Investigation in various regions in Indonesia found indications of the alleged fraud that result from unccountable use and management of BOS funds. Among the findings, including payments that do not fit the technical guidelines, no accountability report, and the use of funds with unaccountable receipt. In the Regulation of the Minister of Education and Culture of the Republic of No. 161/2014, stated that: BOS is a government program that is basically forfunding the nonpersonnel operating costs of the primary education as the implementer of compulsory education program. The purpose of this study were (1) to analyze the accounting cycle and financial accountability for the use of BOS funds in the 2015, (2) to analyze the compliance of the accounting cycle and financial accountability of the BOS funds, (3) to analyze the transparency and accountability of BOS fund’s reports. The observed elementary school is SDIT X in Depok, West Java. Result shows that they do not fully compliance to the appropriate regulatory technical guidelines. On the other hand, the transparency and accountability issues show that: (1) BOS Management Team, Teachers Council and School’s Committee’s involvement in the BOS fund management, and (2) evaluation and comparison of the final report of prior periods, so that transparency and accountability of the use and management of BOS funds can be improved.


TAPPI Journal ◽  
2014 ◽  
Vol 13 (8) ◽  
pp. 65-78 ◽  
Author(s):  
W.B.A. (SANDY) SHARP ◽  
W.J. JIM FREDERICK ◽  
JAMES R. KEISER ◽  
DOUGLAS L. SINGBEIL

The efficiencies of biomass-fueled power plants are much lower than those of coal-fueled plants because they restrict their exit steam temperatures to inhibit fireside corrosion of superheater tubes. However, restricting the temperature of a given mass of steam produced by a biomass boiler decreases the amount of power that can be generated from this steam in the turbine generator. This paper examines the relationship between the temperature of superheated steam produced by a boiler and the quantity of power that it can generate. The thermodynamic basis for this relationship is presented, and the value of the additional power that could be generated by operating with higher superheated steam temperatures is estimated. Calculations are presented for five plants that produce both steam and power. Two are powered by black liquor recovery boilers and three by wood-fired boilers. Steam generation parameters for these plants were supplied by industrial partners. Calculations using thermodynamics-based plant simulation software show that the value of the increased power that could be generated in these units by increasing superheated steam temperatures 100°C above current operating conditions ranges between US$2,410,000 and US$11,180,000 per year. The costs and benefits of achieving higher superheated steam conditions in an individual boiler depend on local plant conditions and the price of power. However, the magnitude of the increased power that can be generated by increasing superheated steam temperatures is so great that it appears to justify the cost of corrosion-mitigation methods such as installing corrosion-resistant materials costing far more than current superheater alloys; redesigning biomassfueled boilers to remove the superheater from the flue gas path; or adding chemicals to remove corrosive constituents from the flue gas. The most economic pathways to higher steam temperatures will very likely involve combinations of these methods. Particularly attractive approaches include installing more corrosion-resistant alloys in the hottest superheater locations, and relocating the superheater from the flue gas path to an externally-fired location or to the loop seal of a circulating fluidized bed boiler.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ramhari Poudyal ◽  
Pavel Loskot ◽  
Ranjan Parajuli

AbstractThis study investigates the techno-economic feasibility of installing a 3-kilowatt-peak (kWp) photovoltaic (PV) system in Kathmandu, Nepal. The study also analyses the importance of scaling up the share of solar energy to contribute to the country's overall energy generation mix. The technical viability of the designed PV system is assessed using PVsyst and Meteonorm simulation software. The performance indicators adopted in our study are the electric energy output, performance ratio, and the economic returns including the levelised cost and the net present value of energy production. The key parameters used in simulations are site-specific meteorological data, solar irradiance, PV capacity factor, and the price of electricity. The achieved PV system efficiency and the performance ratio are 17% and 84%, respectively. The demand–supply gap has been estimated assuming the load profile of a typical household in Kathmandu under the enhanced use of electric appliances. Our results show that the 3-kWp PV system can generate 100% of electricity consumed by a typical residential household in Kathmandu. The calculated levelised cost of energy for the PV system considered is 0.06 $/kWh, and the corresponding rate of investment is 87%. The payback period is estimated to be 8.6 years. The installation of the designed solar PV system could save 10.33 tons of CO2 emission over its lifetime. Overall, the PV systems with 3 kWp capacity appear to be a viable solution to secure a sufficient amount of electricity for most households in Kathmandu city.


PEDIATRICS ◽  
1970 ◽  
Vol 46 (6) ◽  
pp. 870-870
Author(s):  
T. E. Cone

infant-from Latin infans; in (neg.) + fans speaking (fans is the participle). In Roman law infant means a child not old enough to talk... Cretin-Old French-chretien, a Christian. Perhaps used first as a perjorative term by the ancient Romans because to them the first Christians were stupid enough to "turn the other cheek" when attacked by mobs or by the lions in the Roman amphitheater. Meconium-from Greek mekonion meaning the poppy juice obtained from pressing the whole plant which gives a thick Juice of black, greenish-brown color. The intestinal content of the newborn infant has a similar consistency and appearance and so Galenadopted the term for the content of the bowels of newborn infants. (Meconism means the opium habit). lcterus-from Greek ikteros, a yellow bird, probably the golden thrush or a species of oriole. Pliny relates that if a person suffering from jaundice looks at a yellow bird, the bird will die and the patient recovers. Icterus was first used in pediatrics by Ludwig von Buhl (1816-1880) when he described icterus neonatorum.


1992 ◽  
Vol 25 (10) ◽  
pp. 55-67 ◽  
Author(s):  
R. C. Squires

The performance of Exxflow, a patented form of crossflow microfiltration, treating industrial wastewaters containing mixed heavy metals discharged by two types of industry is quantified and compared with the traditional technologies used for such treatment. Pilot trial results using Exxflow are shown and compared to the performance of the full scale plants now operating on these effluents. The operating costs of the Exxflow process are estimated for the two plants. One of which has been operating for 18 months and the other about 4 months. The Exxflow process is described and improvements which are being developed to lower the operating costs are presented. It is shown that industrial effluents containing mixed heavy metals are very effectively treated by the Exxflow process and since the installation of the plants the treated effluent has been of a quality suitable for discharge to the River Thames in one case and to a sewage treatment plant in the other. Unlike other processes, Exxflow has shown that it can successfully treat effluent containing mixed metals and that removal of antimony from mixed metal waste waters is affected by the concentration of sodium sulphate in the wastewater.


1959 ◽  
Vol 52 (2) ◽  
pp. 230-237 ◽  
Author(s):  
D. J. C. Jones

1. Four varieties of marrow stem kale, three of thousand headed kales, Hungry Gap Kale and Rape-Kale were grown at three centres in mid-Wales. They were sampled in the early winter period and separate leaf and stem samples analysed for the proximate constituents and minerals.2. Leaf to stem ratios were measured on both a green and dry matter basis and the latter values used to calculate whole plant values for the chemical constituents.3. The leaves of the marrow stem kales were higher in dry matter than the stems, except in the case of the Purple Stem Kale. This variety resembled the thousand headed and rape-type kales in having a higher dry matter in the stems. On a dry matter basis, the leaves of all the varieties were richer than the stems in ether extract, crude protein, total ash and all the minerals except potassium and sodium. These elements occurred to a greater extent in the stems of the fleshy stemmed marrow stem kales than in the leaves. The stems were higher in crude fibre and nitrogen-free extractives.4. The leaves of the rape-type kales were higher than those of the other varieties in silica, phosphorus and potassium. They were the best source of phosphorus on a whole plant basis. The marrow stem kales had considerably higher leaf and stem values for sodium and were markedly superior to the other varieties as a source of the element.


2011 ◽  
Vol 40 (2) ◽  
pp. 343-351 ◽  
Author(s):  
Paulo Levi de Oliveira Carvalho ◽  
Ivan Moreira ◽  
Antonio Claudio Furlan ◽  
Diovani Paiano ◽  
Liliane Maria Piano ◽  
...  

Two experiments were carried out with the objective of evaluating the performance and carcass traits of growing and finishing pigs fed rations with sticky coffee hull silage. In experiment 1, the coffee hulls were ground through a 4-mm screen and ensiled with 30% water and enzymatic-bacterial inoculant and evaluated in digestibility trial with 15 crossbred pigs distributed in a completely randomised design. Overall, the ensiling process did not improve the digestibility of the sticky coffee hulls. In experiment 2, it was used 60 pigs (32.52 to 59.58 kg) in the growing phase and 55 pigs (61.70 to 90.27 kg) in the finishing phase, distributed in a completely randomised design with five diets (0, 4, 8, 12 and 16% of sticky coffee hull silage) and six replicates. In the growing and finishing phase, inclusion of levels of sticky coffee hull silage did not affect feed intake, weight gain, and plasma urea nitrogen. However, in the finishing phase, feed conversion improved as the levels of sticky coffee hull silage increased. Responses by backfat thickness and marbling were quadratic, whereas empty stomach weight increased linearly when sticky coffee hull silage was included in the diet. Sticky coffee hull silage has good nutritional value and if used in levels up to 16% of the diet, it does not impair performance of pigs in the growing and finishing phases and it results in leaner carcasses. However, the economic feasibility of its use depends on the price relationship of this by-product with the other feedstuffs.


Author(s):  
Jeong Hun Kim ◽  
Nicholas Theodore ◽  
Rajiv Iyer ◽  
Amir Manbachi ◽  
Richard Um

Abstract Wasted time in the operating room results in higher operating costs and greater post-operative complications. One effective way to reduce operation time is automating basic processes that occur during surgery. Given the rise of smart-home devices, implementation of virtual assistants became a feasible solution in many medical settings. With a consumer smart-home device and off-the-shelf components, we engineered a voice-controlled smart surgical bed that adjusts the bed configuration via a voice input. The resulting device is expected to optimize human resources and reduce surgical site infection by eliminating the need of a traditional touch control mechanism. Future work is needed to develop its proprietary hardware and software, and continuous collaboration with medical personnel to bring this device into market.


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