Scrubber System Research Articles

Study on characteristics of marine heavy fuel oil and low carbon alcohol blended fuels at different temperatures

The current study proposes heavy fuel oil (HFO)-methanol/ethanol blends as sustainable way shipowners can limit their emissions to acceptable levels. However, the blends of HFO- methanol/ethanol present miscibility problems, and little has been reported about the improvement of this situation within the existing literature. Hence, the primary aim of the current study is to prepare a blend of HFO- methanol/ethanol in the presence of n-butanol, tetrahydrofuran (THF), and polyoxymethylene dimethyl ethers (PODE), that can be kinetically stable for at least 48 h. Also, the ternary systems’ viscosity, corrosivity, and sulfur content relative to that of neat HFO were ascertained. Finally, an economic feasibility of using the proposed ternary systems in comparison to an HFO + scrubber system, as two different pathways of meeting SOx emission standards is conducted. The ternary blends were undisturbed at an experimental temperature (20 °C, 40 °C, and 50 °C) for at least 48 h to observe their mutual solubility. After maintaining a 2-day single-phase solution, the best co-solvent for methanol-containing blends was PODE, and that of ethanol was THF. The oxygenated fuels decreased the kinematic viscosity well below that of a preheated/unheated HFO; reducing preheating cost and energy. The corrosivity of the ternary systems were extremely low and negligible. The HFO blend at 1:1 ratio showed a significant decrease in sulfur content of neat HFO. The study promotes the wide use of oxygenated fuels in the shipping industry; a positive step towards decarbonizing this transportation sector.

Green Shipping—Multifunctional Marine Scrubbers for Emission Control: Silencing Effect

Scrubber systems abate the sulphur oxide emissions of engines when cheap fuel oils that are high in sulphur content are employed as combustibles. However, the ships with these voluminous devices installed on board is space demanding. This work analyses the feasibility of incorporating the acoustic abatement of the exhaust gas noise functionality into the scrubber design to provide a combined scrubber–silencer system. For this purpose, a finite element analysis is performed on a simple expansion chamber, which is assessed using both analytical and experimental data. The transmission loss is the acoustic parameter chosen in this work. The numerical model depicts a good correlation with the transmission loss measured on a model scale scrubber. Finally, scrubber geometry modifications alter the transmission loss, changing and/or enhancing its featuring. These abilities indicate the feasibility to confer to scrubber silencing effects.

Experimental Study on Simultaneous Desulfurization and Denitrification by DBD Combined with Wet Scrubbing

A dielectric barrier discharge (DBD) reactor combined with a wet scrubbing tower was used to carry out an experimental study on desulfurization and denitrification. The effects of the packing type, packing height, spray density, mass fraction of the NaOH solution, discharge power in the DBD reactor, and simulated flue gas flow rate on the desulfurization and denitrification efficiency were analyzed, along with the influence weight of each factor, using orthogonal testing. The experimental results showed that SO2 was easily absorbed by the scrubbing solution, while the desulfurization efficiency remained at a high level (97–100%) during the experiment. The denitration efficiency was between 12 and 96% under various operating conditions. Denitration is the key problem in this system. The influence weights of the DBD power, simulated flue gas flow rate, mass fraction of the NaOH solution, spray density, packing type, and packing height on the denitration efficiency were 56.96%, 18.02%, 11.52%, 5.02%, 4.33%, and 4.16%, respectively. This paper can provide guidance to optimize the desulfurization and denitrification efficiency of this DBD reactor combined with a wet scrubbing system.

Evaluating the impact of several scrubbing systems on the tar removal efficiency from producer gas

Evaluating the impact of several scrubbing systems on the tar removal efficiency from producer gas

화물 작업용 스크러버의 세정수 처리에 관한 이론적 제안

In the past, international efforts have been made to prevent pollution from ships, and as a result, the International Convention on Pollution Prevention(MARPOL) has been adopted. However, there is a growing need for stronger pollution control as international perceptions of environmental issues such as global warming change. As part of this, regulations on emissions from ships have been implemented, especially regulating the sulfur content. Ships are responding by using low sulfur fuel, LNG fuel and installing scrubbers. The reduction of sulfur content through scrubber systems is under international discussion as additional regulatory needs are recognized as contaminated washwater. Scrubbers have been operated on tankers for cargo operations for a long time, and no regulations have been made on contaminated washwater generated from these cargo scrubbers. In response, this study proposes international discussion and regulatory needs for contaminated wahswater generated from cargo operations, as well as several treatment measures. Through this, it will be able to reduce pollution caused by ships while preemptively responding to the situation where regulations on environmental pollution are continuously strengthened.

Enrichment of Biogas by Microalgal Scrubbing System and Value added Products Synthesis

Biogas is composed of CH4 (50-60%) and CO2 (40-50%), therefore scrubbing (removal) of CO2 from biogas is imperative as high concentration of it reduces the calorific value and limits its end application. Problems associated with physiochemical process can be alleviated through microalgae as they are efficient in utilizing the CO2 as its carbon source that can be technically termed as CO2 sequestration. This study aims to apply the use of a microalgae CO2 capturing system using Chlorella sorokiniana and Scenedesmus obliquus that have higher photosynthetic capacity and sequestration of carbon dioxide subsequently and transforming into biomass. Chlorella sorokiniana had a total biomass yield of 1.59 g/L and 1.98 g/L for unpurged and purged respectively. Scenedesmus obliquus on the other had a better yield over Chlorella sorokiniana with an overall biomass of 1.7 g/L for unpurged and 2.4 g/l under mixotrophic condition. Upon analysis of lipid content in the biomass, the cultures that were grown under mixotrophic condition were found to yield 3.45 and 3.28 fold higher as compared to unpurged sample in Chlorella and Scenedesmus respectively. Under purged conditions, Chlorella sorokiniana had the maximum yield of 5.5 mg/g of vitamin E compared to Scenedesmus obliquus with a comparatively lower yield of 2.32 mg/g. Overall, the increase in the specific growth rate and doubling time indicated that a better adaptability and utilization of carbon source in the purged sample which was provided in the form of 50% citric acid and carbon dioxide. This provides evidence in support of Chlorella sorokiniana for having a higher potential in the area of nutraceuticals. Along with purifying the biogas produced from an anaerobic digester fed with food waste.

Treatment of Flue Gas from an Infectious Waste Incinerator using the Ozone System

Recently, levels of air pollution caused by exhaust gases from infectious waste combustion have been rising at a startling rate. Pollutant gases such as carbon monoxide (CO) and nitrogen dioxide (NO2) have numerous health implications when unsafe amounts are released into the atmosphere. Thus, Pollution Control Systems (PCS) and Gas Cleaner Systems (GCS) play an important role in industries and the monitoring of incinerators. This research evaluated the GCS of rotary kilns in medical facilities located in the Northeast of Thailand. Data was collected from various sites, analyzed, and examined. Furthermore, Ozone (O3) technology was applied to the rotary kiln allowing for the collection of new information on the pollution treatment systems. O3 technology was installed along with the Wet Scrubber System (WSS) catalyzing the oxidation of O3 and pollutant gases. In addition, a chiller was added to control and stabilize the temperature of the water. After the water temperature was controlled, the concentration of O3 increased resulting in an efficient pollution treatment system. Levels of pollutant gas emission were found to be beneath control standards of both Thailand and those of the U.S. EPA. TSP content was reduced significantly from 22.0 mg/m³ to 3.4 mg/m³ (97%), CO content from 13.6 mg/m³ to 1.7 mg/m³ (96%), and NO₂ content fell from 16.3 (mg/m³) to 2.0 mg/m³ (99%). It is clear that the rotary kiln and Ozone technology should be used together in order to create a new and far more effective method of pollution treatment in small and mid-sized cities of Thailand.

INNOVATIVE SYSTEM WITH SIMULTANEOUS ENERGY RECOVERY IN SHIPS FOR COMPLETE DESULPHURISATION OF EXHAUST GAS DERIVED BY HEAVY OIL

This paper presents an innovative worldwide method of total of gas combustion-derived ships on heavy fuel diesel engines. For the treatment of waste aqueous solution derived from with aqueous solution NaOH the exhaust gas and capture the S from . For the treatment wastewater plant is necessary to have big surface and quantity of salt water. But unfortunately, the space free on the ships are very restricted and further consequently born stability problems for the ships. This proposal innovative methodology with new approx and new design overcame the limitations and the low performance of the actual scrubber systems and the negative provoked enormous environmental impact of these emissions and not complies the IMO international regulations. The method exposed in this paper overcame the requirement its international regulations of IMO (international maritime organization) and is Patent N. Pittas .

Controlling emissions from an ocean-going container vessel with a wet scrubber system

This study assessed the real-world gaseous and particulate emissions for a wet scrubber retrofit to an existing container ocean-going vessel as it cruised from Tacoma Washington to Anchorage Alaska. The vessel was operated with a high sulfur heavy fuel oil and testing was performed following the ISI 8178 E2 steady test cycle. The scrubber unit provided more than a 95% removal efficiency of sulfur dioxide (SO2) emissions across all engine loads. In contrast to the higher removal efficiencies for SO2 emissions, the scrubber only removed approximately 10% (ISO weighted reduction) of particulate matter (PM2.5) emissions. PM2.5 composition was primarily composed of sulfate, followed by organic carbon (OC) and elemental carbon (EC). Pre- and post-scrubber sulfate levels were similar, indicating why the PM2.5 removal efficiencies were low. This phenomenon was likely due to the formation of small sulfuric acid particles in the scrubber fluid that were not efficiently removed by impaction, influencing PM2.5 mass emission measurements.

Parametric analysis and design optimization of wet SOx scrubber system in marine industry

Regulations on emission control of sulfur oxides (SOx) contained in exhaust gas (EG) from ships’ engines enter into force. In the recent past, emission control regulations have continually been made more stringent. Consequently, there is an urgent need for novel emission abatement technologies for ship operators, to satisfy the regulations. The objective of this study was to investigate a novel design of a wet SOx scrubber prepared for compliance with the new regulations and to identify the key parameters affecting the SOx removal efficiency and design optimization. The model of wet SOx scrubber system was developed and validated using actual experimental results. On the basis of a parametric analysis, a design for an open-loop mode involving the cooling of the EG inlet temperature via an EG inlet/wash water heat exchanger is proposed. Design optimization results showed that the liquid-to-gas (L/G) ratio and EG inlet temperature could be adjusted to reduce the required power of a seawater (SW) pump by 31.72% and 51.17% for an open-loop system operated inside and outside designated emission control areas, respectively. For a closed-loop system, the adjustment of the L/G ratio, circulating wash water’s (WW’s) temperature, and chemical dosing flow rate reduced the amount of dose input and required power of the SW pump and circulating WW pump by 11%, 66%, and 49%, respectively.

Wastewater Management of Wet Scrubbers in Waste-to-energy Facilities: a Life Cycle Analysis

Nowadays, increasing attention is focused on the indirect impacts of emission control technologies and the potential burden shifting. A clear example is the generation of wastewater when wet scrubbing systems are used for flue gas cleaning. The present study takes into consideration a typical wet scrubber for waste-to-energy plants and the available options for wastewater management: physicochemical treatment, evaporation or valorisation. A comparative assessment of the environmental footprint of the alternatives is performed by taking into account the burdens related to the supply of reactants, energy and the disposal of process residues (solid and liquid waste streams). It is thus shown that the recovery of a marketable product from the effluent produces a net environmental benefit, while the choice between wastewater discharge or evaporation represents only a shift of burden between the water and the soil compartments.

Plant Trials of Filter aid AS-43124M for Dewatering of Sludge from Gas Scrubbing System

Plant Trials of Filter aid AS-43124M for Dewatering of Sludge from Gas Scrubbing System

Computer Aided Simulation POME Biogas Purification System

About three (3) tonnes of palm oil mill effluent (POME) is generated when one (1) tonne of crude palm oil (CPO) is produced. Microbial digestion treatment is commonly used in Malaysian palm oil mills due to the low capital expenditure (CAPEX) and operational expenditure (OPEX). However, anaerobic digestion of POME produces methane gas which is 21 times more harmful than carbon dioxide. 1m<sup>3</sup> of POME could generate 27m<sup>3</sup> of biogas at standard temperature and pressure with approximate caloric value of 20 MJm<sup>-3</sup> under optimum conditions Thus, methane capturing biogas plant to address sustainability issue is included as part of effluent treatment plant. Many mills start to utilise the biogas energy to replace palm kernel shell which could be sold as renewable solid fuel. Although untreated biogas may be good enough for boiler fuel, internal combustion engines need a fairly homogeneous fuel with methane (CH<sub>4</sub>) content up to 80 % and hydrogen sulphite (H<sub>2</sub>S) content less than 200 ppm in order to ensure the optimum engine performance. Water scrubber system is widely used in gas purification. Computer aided biogas purification system simulation involving water scrubber and flashing drum is presented in the effort to produce IC engine fuel. ChemCAD simulation result shows that POME biogas purification process is feasible at 10 bar pressure and 25°C ambient temperature.

Techno-economic assessment at full scale of a biogas refinery plant receiving nitrogen rich feedstock and producing renewable energy and biobased fertilisers

Anaerobic digestion of nitrogen (N) rich substrates might be hindered when ammonia (NH3) formation reaches toxic levels for methanogenic microorganisms. One possible strategy to avoid inhibiting conditions is the removal of NH3 from digestate by stripping and scrubbing technology and by recirculating N depleted digestate back to the digester. This study aimed to i) monitor the performance (mass and energy balances) of a full scale digestate processing cascade that includes an innovative vacuum side stream NH3stripping and scrubbing system, ii) assess the production cost of ammonium sulphate (AS) solution and iii) evaluate its fertiliser quality. The use of gypsum to recover NH3 in the scrubbing unit, instead of the more common sulphuric acid, results in the generation of AS and a fertilising liming substrate. Mass and nutrient balances indicated that 57% and 7.5% of ammonium N contained in digestate was recovered in the form of a 22% AS and liming substrate, respectively. The energy balance showed that about 3.8 kWhel and 59 kWhth were necessary to recover 1 kg of N in the form of AS. Furthermore, the production cost of AS, including both capital and operational costs, resulted to be 5.8 € t−1 of digestate processed. According to the fertiliser quality assessment, this technology allows for the recovery of NH3in the form of salt solutions that can be utilised as a substitute for synthetic mineral nitrogen fertilisers.

Experimental and Numerical Investigation of the Effect of Integration of a Flooded-Bed Scrubber into a Longwall Shearer on Airflow along a Coal Mine Longwall Face

Dust control is one of the most difficult challenges for underground coal mine operators, especially longwall mine operators. The most widely used dust control technologies at a longwall section are ventilation air and water sprays, whereas a continuous miner section has the added advantage of having a dust scrubber built into the continuous miner. To test the potential benefits of integrating a flooded-bed scrubber into a longwall shearer, the authors designed and built a dust scrubber system for a full-scale mock-up of a longwall shearer. The mock-up was installed in the longwall test gallery at the Pittsburgh Research Laboratory (PRL) for testing. Air quantity surveys were performed at different cross-sections of the test gallery at a fixed face-air quantity, but at different scrubber airflow rates to quantify the distribution of air in the test gallery. Subsequently, a computational fluid dynamics (CFD) model of the PRL test gallery was developed and validated. In this study, the effect of the flooded-bed scrubber on airflow pattern in the test gallery is investigated using the validated CFD model. This model can be used further to predict the dust capture efficiency of the scrubber and to develop new techniques to reduce dust concentration in longwall sections.

Removal of Cement Dust Particulates via Fully Submerged Self‐Primed Venturi Scrubber

AbstractIn the last few decades, researchers have aimed to improve the removal efficiency of air pollutants using several engineered devices. Here, cement dust removal is investigated using the water scrubbing technique by applying a self‐priming venturi scrubber in fully submerged conditions to study the effect of various operating parameters on performance. This study carries out optimization to develop a model. The removal efficiency of particulates acts as the functional process parameter and its related interaction terms are discussed in this work. Response surface methodology is applied to optimize the process output response. The developed model and design expert platform, inbuilt with the central composite design technique performs the process optimization. This helps in comparing the input and output variables. The maximum removal efficiency obtained is 99.77% at a throat gas velocity of 60 m s−1, an inlet cement dust loading rate of 3.1 g m−3, and a liquid level of 100 cm in the external cylinder under fully submerged conditions. Moreover, recyclable household greywater is used as a scrubbing liquid owing to its low‐cost and availability in sufficient quantities. The proposed scrubber system efficiently removes particulate matter such as cement dust particulates from the environment.

A new model of Algal Turf Scrubber for bioremediation and biomass production using seaweed aquaculture principles

An increase in the use of macroalgal biomass for different applications is required in development of efficient cultivation systems and low-cost culture media. With this in mind, the present work proposes modifications to the Algal Turf Scrubber (ATS) system inducing the establishment of a monospecific culture of Ulva ohnoi through a seeding process, speeding up the maturation time and increasing efficiency and productivity. Bench-scale units of Seeded Algal Turf Scrubber (sATS) were built to test different types of algal attachment substrates (nylon and jute fiber) and water flow conditions (stagnant and continuous) besides evaluating of coverage rate, daily growth rate, and nutrient removal capacity. The results were promising. The coverage rate by U. ohnoi seedlings was higher when nylon substrate was combined with continuous water flow (74.41 ± 6.79%). Changes in nutrient concentration demonstrated a dose-dependent pattern with complete removal of P-PO43− in 24 h at all concentrations tested when the system had 18 days of maturation and N-NH4+ was completely removed in 24 h at all concentrations tested in both maturation times (18 and 47 days). Daily growth rates presented satisfactory values, reaching maximum of 4.8 ± 0.6% day−1. In conclusion, it was demonstrated that the bench-scale sATS system was successful to enable cultivation of U. ohnoi by seeding, resulting in good quality biomass production and efficient nutrient removal, thus justifying upscale experiments.

Химическая коррозия каталитических материалов в системе очистки отработавших газов судовых энергетических установок

Object and purpose of research. This paper discusses exhaust gases of marine power plants. The purpose of this study was to investigate acid-mix corrosion of porous permeable catalysts in exhaust scrubbers. Materials and methods. Specially developed program of tests intended to analyse the effect of acid mix upon catalyst in marine exhaust scrubber, as well as the studies on sulfur-nitrogen acid mix upon corrosion behavior of porous permeable catalysts. Main results. The study yielded the data on acid-mix effect upon porous permeable catalysts used in marine exhaust scrubbers. Conclusion. The results of these tests made it possible to estimate how much the catalysts used in marine scrubbing systems are affected by their aggressive environments, as well as to suggest tailor-made compositions of catalytic materials so as to meet the requirements to exhaust cleaning quality.

A Comparative Life Cycle Assessment of Marine Desox Systems

Abstract With new sulphur oxides emission limits carried out in 2020, multiple desulphurisation methods have been proposed. The main desulphurisation scrubber systems were chosen and investigated using life cycle assessment. The whole system life is divided into the construction and operational phases. Three different systems classified by desulphurisers, namely, seawater, NaOH, and Mg-based systems, were modelled in GaBi software. Moreover, environmental, economic and energy aspects (3E model) were introduced for further analysis. Through this study, some conclusions have been drawn. As for the environmental aspect, the seawater system has the most pleasing performance since the primary emissions come from 1.24E+03 kg CO2 and 1.48E+01 kg chloride. The NaOH system causes 1000 times more emissions than the seawater. The Mg-based system has less pollution than the NaOH system, with 5.86E+06kg CO2 and 3.86E+03 kg chloride. The economic aspect is divided into capital expenditure (CapEx) and operational expenditure (OpEx) to estimate disbursement. The seawater system also has the most favourable cost appearance, which takes 1.7 million dollars without extra desulphuriser expenses, based on 10MW engine flue gas treatment. The next is the Mg-based system, which cost 2 million dollars in CapEx and $ 1200/year in OpEx for the desulphuriser. NaOH uses about 2.5 million dollars for construction and $ 30000/year in desulphuriser. As for the energy aspect, the seawater and Mg-based systems use less non-renewable energy than the NaOH system in the construction phase. In conclusion, the seawater system shows the best performance and could be an alternative in SOx control technologies. This study sheds light on the comprehensive evaluation of marine environmental protection technologies for further optimisation.

Substrate properties as controlling parameters in attached algal cultivation.

There is growing interest in attached algae cultivation systems because they could provide a more cost- and energy-efficient alternative to planktonic (suspended algae) cultivation systems for many applications. However, attached growth systems have been far less studied than planktonic systems and have largely emphasized algae strains of most interest for biofuels. New algal biorefinery pathways have assessed the commercial potentials of algal biomass beyond biofuel production and placed more emphasis on value-added products from that biomass. Therefore, algal strain selection criteria and biomass cultivation methods need to be updated to include additional strains for improved efficiency. One possible way of improving attached cultivation systems is through engineering substrate surface characteristics to boost algal adhesion and enable strain selective algal colonization and growth. This review explores the effect of substrate chemical and topographical characteristics on the cultivation of attached algae. It also highlights the importance of considering algal community structure and attachment mechanisms in investigating attached algae systems using the example of filamentous algae found in algal turf scrubber (ATS™) systems. KEY POINTS : • Attached algal cultivation is a promising alternative to planktonic cultivation. • Performance increase results from tuning surface qualities of attachment substrates. • Attachment adaptation of periphytic algae has innate potential for cultivation.