Published at : 25 Jan 2021
Volume : IJtech
Vol 12, No 1 (2021)
DOI : https://doi.org/10.14716/ijtech.v12i1.4245
Totok Soehartanto | Department of Instrumentation, Faculty of Vocation, Institut Teknologi Sepuluh Nopember (ITS), Jl. Arief Rahman Hakim, ITS campus Keputih, Sukolilo, 60111 Surabaya, Indonesia |
Ruri Agung Wahyuono | Department of Engineering Physics, Faculty of Industrial Technology and System Engineering, Institut Teknologi Sepuluh Nopember (ITS), Jl. Arief Rahman Hakim, ITS campus Keputih, Sukolilo, 60111 Surab |
Putri Yeni Aisyah | Department of Instrumentation, Faculty of Vocation, Institut Teknologi Sepuluh Nopember (ITS), Jl. Arief Rahman Hakim, ITS campus Keputih, Sukolilo, 60111 Surabaya, Indonesia |
Biondhi Ubaidhilah | Department of Instrumentation, Faculty of Vocation, Institut Teknologi Sepuluh Nopember (ITS), Jl. Arief Rahman Hakim, ITS campus Keputih, Sukolilo, 60111 Surabaya, Indonesia |
Biogas impurities
CO2 and H2S decrease the quality of biogas, which leads
to a reduced caloric value and corrosive behavior, respectively. A
vertical/columnar wet scrubber has been widely employed for biogas purification
in which the absorption of impurities strongly depends on the contact time and
surface area between the biogas and water. The drawback of this method lies in
the stability of CH4 production due to the influence of the
bioreactor conditions and the fluctuating condition of the surrounding
environment. In this work, we present a novel design of simple water absorption
columns embedded with an ultrasonic nebulizer for biogas purification. In this
designed system, CO2 and H2S become dissolved in the
water, as the CH4 characterized by water low solubility is released
on the surface of the water by using an ultrasonic diffuser/nebulizer. We
optimized the water absorption performance by varying the water pH in the range
6.0–7.3. The results indicate that water pH affects biogas purification in the
designed system. The optimum pH condition was 6.78, which yielded CH4
enrichment of 11%, O2 increase of 29%, CO2 reduction of
32%, and H2S reduction of 99.8%. To evaluate the biogas purification
process in the upscaled system, a model and SIMULINK-based simulation were
developed to predict the biogas purification process.
CH4 enrichment; Impurities removal; Modeling and simulation; Water pH
Biogas is a renewable energy source generated from anaerobic processes
of organic substrates, such as animal, plant, or household organic waste (Petersson, 2014; Ghatak
and Mahanta, 2017). Typically, biogas
contains methane (CH4), carbon dioxide (CO2), and
hydrogen sulfide (H2S) (Arutyunov et al., 2020).
CH4 can be used as an energy source for electricity generation,
vehicle fuel, or as a raw material in the industry ( Wahyuono et al., 2015; Chen et al., 2017).
However, the other gases contained in biogas are considered impurities. For
example, CO2 which causes ozone depletion and lowers the heating
value of biogas, and H2S is so strongly corrosive and can damage
industrial equipment that uses biogas. Therefore, the recent development of
biogas technology not only focuses on biogas production but also on the biogas
purification process, particularly the removal of CO2 and H2S
(Baena-Moreno et al., 2019).
There exist various biogas purification methods including physical and chemical absorption, adsorption, gas permeation through the membrane, and cryogenic methods (Horikawa et al., 2004; Abatzoglou and Boivin, 2009; Ofori-Boateng and Kwafie, 2009; Songolzadeh et al., 2014; Belaissaoui et al., 2016; Kusrini et al., 2016; Maile et al., 2017;). Of these, the spray-type wet scrubber is widely utilized in the industry for biogas purification, as the process is relatively simple with strong adaptability. The spraying water scrubber passes the biogas in the vertical vessel, and the water is sprayed from the top of the vessel (Wang et al., 2020). In the spray-type wet scrubber method, the effectiveness of impurities absorption is controlled by the dimension of the wet scrubber, as the absorption is a function of the contact surface area and contact duration (Tahir et al., 2015; Sarono et al., 2016; Kapoor et al., 2017; Noorain et al., 2019). This in turn leads to the high cost of construction and operation of the spray-type wet scrubber. Moreover, the spray-type wet scrubber is known to be merely effective for absorbing CO2, H2S or other impurities in biogas but unable to stabilize or maintain the CH4 concentration in biogas (Islamiyah et al., 2015). Therefore, CH4 gas accumulation process will not occur in the spray-type wet scrubber method as the purified biogas will pass directly through the biogas outlet to be used as an energy source (Wang et al., 2020). It should also be noted that CH4 concentration in biogas varies as the operational condition of the anaerobic bioreactor is altered. Practically, CH4 concentration must be kept to a minimum value (~ 65%) so that the energy source is sufficient to meet the minimum load (Shah et al., 2016).
In this work, we propose a new system of purification that dissolves biogas into a water absorption system that consists of two absorption columns, the so-called dipping-nebulizing water absorption system. This proposed system addresses the abovementioned drawbacks of vertical spray type water scrubber. The purification process in the proposed system mainly combines a dissolution technique by dipping the biogas outlet into water and a nebulizing technique to pull off the dissolved CH4 to the water surface, with its subsequent release in the head space of the main water absorption column. The proposed dipping-nebulizing water absorption system has been proven to work with relatively high purification efficiency. Furthermore, this proposed system does not require many mechanical components; hence, the operational cost of the upscaled system should not be a major concern. Additionally, a SIMULINK simulation based on the mathematical model for biogas purification was performed to offer insights into the proposed process in an upscaled dimension.
A
miniaturized dipping-nebulizing water absorption system for biogas purification
has been successfully developed, especially for CO2 and H2S
reduction. The ultrasonic nebulizer was embedded in one of the bioreactor’s
water absorption columns to extract CH4 out from the first water
volume for purification. The biogas purification was found to be water-pH
dependent, and an optimum pH condition was observed. Of the investigated pH
levels, the highest purification of biogas was achieved by using water with a
pH of 6.78. At the optimum pH condition, the concentration of CH4
and O2 increased by 11 and 29%, respectively, whereas CO2
and H2S was efficiently suppressed by as much as 32 and 99.8%,
respectively. To upscale the system, better operational conditions were
simulated using a model. Further research will focus on the optimization of
water pH to yield higher CH4.
The
author would like to thank Badan Riset dan Inovasi Nasional Republik Indonesia
for providing research assistance through the Hibah Rencana Induk Riset
Nasional scheme (Grant Contract Number : 132/5P2H/LT/DRPM/2018).
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Abatzoglou, N., Boivin, S., 2009. A Review of
Biogas Purification Processes. Biofuels, Bioproducts
& Biorefining, Volume 3, pp. 42–71
Abdurrakhman, A.,
Adhim, M.M., Widjiantoro, B.L., 2018. Optimization of H2S Absorption
toward the Alteration in Flow Rate of Biogas Purification System with Water
Scrubber using Particle Swarm Optimization. In:
AIP Conference Proceedings,
Volume 1983, 020014
Arutyunov, V., Nikitin,
A., Strekova, L., Savchenko, V., Sedov, I., 2020. Utilization of Renewable
Sources of Biogas for Small-Scale Production of Liquid Fuels. Catalysis
Today, In Press, Corrected Proof. doi.org/10.1016/j.cattod.2020.06.057
Baena-Moreno, F.M.,
Rodríguez-Galán, M., Vega, F., Vilches, L.F., Navarrete, B., 2019. Review:
Recent Advances in Biogas Purifying Technologies. International Journal of
Green Energy, Volume 16(5), pp. 401–412
Belaissaoui, B.,
Claveria-Baro, J., Lorenzo-Hernando, A., Zaidiza, D.A., Chabanon, E., Castel,
C., Rode, S., Roizard, D., Favre, E., 2016. Potentialities of a Dense Skin
Hollow Fiber Membrane Contactor for Biogas Purification by Pressurized Water
Absorption. Journal of Membrane Science, Volume 513, pp. 236–249
Chen, Y., Moloney,
J.G., Christensen, K.E., Moloney, M.G., 2017. Fused-ring Oxazolopyrrolopyridopyrimidine
Systems with Gram-Negative Activity. Antibiotics, Volume 6(1), pp. 1–11
Fu, X., Wang, Z., Lu, S.,
1996. Mechanisms and Solubility Equations of Gas Dissolving
in Water. Science in China, Series B: Chemistry, Volume 39(5), pp. 500–508
Ghatak, M.D., Mahanta,
P., 2017. Kinetic Model Development for Biogas Production from Lignocellulosic
Biomass. International Journal of
Technology, Volume 8(4), pp. 673–680
Gross,
E.L., Cravotta III, C.A., 2016. Groundwater Quality for 75 Domestic Wells in
Lycoming Country, Pennsylvania, 2014. Scientific Investigation Report
2016-5143, U.S. Department of the Interior and U.S. Geological Survey
Horikawa, M.S., Rossi,
F., Gimenes, M.L., Costa, C.M.M., da Silva, M.G.C., 2004. Chemical Absorption
of H2S for Biogas Purification. Brazilian Journal of Chemical
Engineering, Volume 21, pp. 415–422
Islamiyah, M.,
Soehartanto, T., Hantoro, R., Abdurrahman, A., 2015. Water Scrubbing for
Removal of CO2 (Carbon Dioxide) and H2S (Hydrogen Sulfide)
in Biogas from Manure. KnE Energy, Volume 2(2), pp. 126–131
Kapoor, R., Subbarao,
P.M.V., Vijay, V.K., Shah, G., Sahota, S., Singh, D., Verma, M., 2017. Factors
Affecting Methane Loss from a Water Scrubbing Based Biogas Upgrading System. Applied
Energy, Volume 208, pp. 1379–1388
Kusrini, E., Lukita,
M., Gozan, M., Susanto, B.H., Widodo, T.W., Nasution, D.A., Wu, S., Rahman, A.,
Siregar, Y.D.I., 2016. Biogas from Palm Oil Mill Effluent: Characterization and
Removal of CO2 using Modified Clinoptilolite Zeolites in a Fixed-Bed
Column. International Journal of
Technology, Volume 7(4), pp. 625–634
Latif,
M.A., Mehta, C.M., Batstone, D.J., 2014. Improved Phosphorus Solubility During
Acidic Anaerobic Digestion. In: AWA Biosolids Conference, pp. 1–7, Melbourne,
Australia
Lin,
E.S., 2004. A Modelling Study of H2S Absorption in Pure Water and
in Rainwater. Master’s Thesis, Graduate Program, National University of
Singapore, Singapore
Macgregor, R.J.,
Mather, A.E., 1991. Equilibrium Solubility of H2S and CO2
and Their Mixtures in a Mixed Solvent. The Canadian Journal of Chemical
Engineering, Volume 69(6), pp. 1357–1366
Maile, O.I., Muzenda,
E., Tesfagiorgis, H., 2017. Chemical Absorption of Carbon Dioxide in Biogas
Purification. Procedia manufacturing, Volume 7, pp. 639–646
Ofori-Boateng, C.,
Kwafie, E.M., 2009. Water Scrubbing: A Better Option for Biogas Purification
for Effective Storage. World Applied Science Journal, Volume 5, pp. 122–125
Noorain, R., Kindaichi,
T., Ozaki, N., Aoi, Y., Ohashi, A., 2019. Biogas Purification Performance of
New Water Scrubber Packed With Sponge Carriers. Journal of Cleaner
Production, Volume 214, pp. 103–111
Petersson, A.W., 2014. Biogas Upgrading Technologies – Developments
and Innovations. IEA Bioenergy, Sweden
Shah, D.R., Nagarsheth,
H.J., Pradeep, A., 2016. Purification of Biogas using Chemical Scrubbing and
Application of Purified Biogas as Fuel for Automotive Engines. Research Journal of Recent Sciences, Volume
5, pp. 1–7
Recebli, Z., Selimli,
S., Ozkaymak, M., Gonc, O., 2015. Biogas Production from Animal Manure. Journal
of Engineering Science and Technology, Volume 10(6), pp. 722–729
Sarono., Suparno, O.,
Suprihatin, S., Hasanudin, U., 2016. The Performance of Biogas Production from
Pome at Different Temperatures. International Journal of Technology,
Volume 7(8), pp. 1413–1421
Revsbech, N.P.,
Garcia-Robledo, E., Sveegaard, S., Andersen, M.H., Gothelf, K.V., Larsen, L.H.,
2019. Amperometic Microsensor for Measurement of Gaseous and Dissolved CO2.
Sensors and Actuators B: Chemical, Volume 283, pp. 349–354
Songolzadeh, M.,
Soleimani, M., Takht Ravanchi, M., Songolzadeh, R., 2014. Carbon Dioxide
Separation from Flue Gases: A Technological Review Emphasizing Reduction in
Greenhouse Gas Emissions. The Scientific World Journal, Volume 2014, pp.
1–34
Tahir, M.S., Shahid,
Z., Shahzad, K., Sagir, M., Rehan, M., Nizami, A.S., 2015. Producing Methane
Enriched Biogas using Solvent Absorption Method. Chemical Engineering
Transactions, Volume 45, pp. 1309–1314
Wahyuono, R.A., Hakim,
M.N., Santoso, S.A., 2015. Feasibility Study on the Production of Bioethanol
from Tapioca Solid Waste to Meet the National Demand of Biofuel. Energy Procedia,
Volume 65, pp. 324–330
Wang,
Y., Liu, Y., Wang, Y., 2020. Oxidation Absorption of Hydrogen Sulfide from Gas
Stream using Vacuum Ultraviolet/H2O2/Urea Wet Scrubbing
System. Process Safety and Environmental Protection, Volume 140, pp. 348–355