Wastes in Makkah during Hajj
Annually, millions of Muslims from across the globe converge in the two holy cities of Saudi Arabia: Madinah and Makkah to take part in Umrah and Hajj. The city of Makkah is characterized by significant amounts of municipal solid wastes mainly attributed to the large annual number of visitors coupled with the rapid urbanization as well as the increase in the number of local. Significant amounts of the municipal solid waste generated in the city are dumped into landfills without being treated causing both health hazards as well as environmental degradation (Lucia, 2014). The majority of the landfills in Makkah city is almost reaching their full capacity, and this has led to the accumulation of sludge, emission of greenhouse gasses, waste leachate, and odour. The extent of the problem of solid waste in Makkah city is evident by the daily dumping of about two and half thousand tons of waste into the city’s landfills with the volume increasing to about four thousand tons on a daily basis during the annual Hajj and Ramadan periods (Demirbas et al., 2016).
About twenty-three percent of all the wastes generated in Makkah city comprise of plastic wastes in the form of shopping bags, water cups, food plates as well as plastic bottles. In 2016, the number of solid wastes produced by both the locals and pilgrims during the Ramadan was estimated to be slightly above one million tons of the value projected to be about two million tons by 2040 (Sharma, Gupta & Mehta, 2016) The Waste-To-Energy (WTE) technologies are popularly used across the globe to add value to products and recover energy from different fractions of municipal wastes, and they include anaerobic digestion, pyrolysis, plasma arc gasification, gasification, incineration, transesterification as well as Refuse Derived Fuel (Astrup et al., 2015).
The process of plasma gasification involves the extreme burning of wastes using plasma converting organic matter into synthesis gas or syngas mainly comprising of carbon monoxide and hydrogen. The process entails the use of plasma torch which is powered by electric arc leading to ionization of gas as well as catalysing the organic matter into synthesis gas with slag as the byproduct of the process. The process of plasma gasification is an essential form of waste treatment, and it has been employed in the management of hazardous wastes, biomass, municipal wastes as well as solid hydrocarbons including oil shale, oil sands a, petcock and coal (Anjum et al., 2016).
Plasma gasification involves utilization of inert gas such as argon while hydrogen gas is used when larger torches are used in the process. The electrodes employed in the process range from zirconium, hafnium, copper or tungsten to some alloys. Plasma gasification involves passage of high electric current with very high voltages between two electrodes forming an electric arc which leads to the ionization of the pressurized inert gas as it passages through the plasma (Arena et al., 2015). The temperatures of the electric torch range from four thousand to twenty-five thousand Fahrenheit and the temperatures of the reaction of the plasma is essential for the determination of the formed gas and the structure of the plasma (Lee, 2014). The process allows heating, melting, and vaporization of the wastes and the extreme temperatures is fundamental in promoting molecular dissociation leading to the breakdown of the molecular bonds resulting in the reduction of complex molecules into individual atoms. The process of molecular dissociation using plasma is referred to as plasma pyrolysis, and the final components are in gaseous form (syngas) (Ismail & Nizami, 2016).
The feedstock employed in the process of plasma gasification is mainly organic waste and municipal waste and some time may be hazmat materials or biomedical wastes. The performance of the plasma equipment is dependent on the consistency and content of the wastes used, thus, the need for recycling and presorting of material before the gasification process improving its consistency (Tozlu et al., 2016). The volume of the syngas production during the process is reduced by the increased amount of slag produced from wastes with the high volume of inorganic materials such as construction materials and metals. One of the advantages of the plasma gasification is the production of inert and safe to handle slug, although the type of gas produced may be defined by the use of particular materials (Perna, Minutillo & Jannelli, 2016).
Furthermore, ensuring that the wastes are shredded before they are put into the main chamber fosters increased production of gas, and this is attributed to the efficient transfer of energy leading to increased material breakdown. The process of plasma gasification can also be enhanced through the addition of steam (Bosmans et al., 2013). The yields of the plasma gasification mainly comprise of a synthetic gas with high-calorie value comprising of hydrogen and carbon monoxide gasses (Portugal-Pereira & Lee, 2016). The presence of inorganic matter in the wastes is melted instead of being broken down, and they include metals, ceramic, and glass. The process does not lead to the formation of toxic gasses such as sulfur dioxide, furans, nitrogen oxides and dioxins because of the high temperatures and absence of oxygen gas (Andreadou & Martinopoulos, 2016). Some dioxins are formed during the cooling of the synthesis gas. The inert slag produced is then granulated for use in construction works while metals can be recovered and sold as the commodity. The gas produced can be used sustainably in the process by using it to run the equipment turbines (Miandad et al., 2017).
Advantages of plasma gasification
- The gas emissions from the process are cleaner compared to those from incinerators and landfills (Khan & Kaneesamkandi, 2013).
- Processes organic waste into syngas that can be used to generate thermal energy and electric power (Agboola & Saleh, 2016).
- A safe method of eliminating hazardous and medical wastes (Pan et al., 2015).
- The process does not lead to the production of furans and dioxins common to incinerators because of the extreme temperatures and oxygen starved combustion (Ouda & Cekirge, 2013).
- Destroys hazardous wastes in an environmentally friendly manner (Aga et al., 2014).
- Valued added products are produced from the slug generated such as metals
- The vitrified slug can be generated and used in construction works (Jannelli et al., 2015).
- Harmful wastes are prevented from reaching landfills (Nizami et al., 2015).
- Leads to recovery of bottom ash, fly ash and other particulates preventing them from entering landfills (Panicker, Philip & Amani Magid, 2016).
- Equipment is limited in number and requires frequent maintenance (Sharma & Ghoshal, 2015).
- High operational costs compared to those incurred in incineration
- There is production of negative or little net energy (Cammack, Freyand & Robson, 2015).
- Use of wet feed leads to high power consumption and limited production of syngas
- Requires massive investment costs during the setting up compared to those of incineration and landfills use (Nizami et al., 2017).
Uses of Hydrogen as a fuel
The Waste-to-Hydrogen-Energy is one of the possible sources of alternative energy in the Kingdom of Saudi Arabia, notably through the use of hydrogen gas derived from waste solid management processes like the plasma gasification (Nizami et al., 2016). The country generates an enormous amount of municipal solid wastes, particularly during the Hajj in the city of Makkah coupled with significant volumes generated from the agricultural and industrial processes (Watkins & McKendry, 2015). Currently, the city’s wastes are partially recycled and segregated before being dumped in the landfill with no energy recovery (Verhelst, 2014). Thus, the capabilities of the country, venturing into production of hydrogen to be used as a source fuel from the massive amounts of wastes is promising (Dodds et al, 2015). According to O’hayre et al. (2016), the main parameters considered for adequate production of hydrogen gas from the plasma gasification of the solid wastes include biodegradability, cost effectiveness as well as high carbon contents of the wastes (Lucia, 2014).
Hydrogen gas can be as fuel capable of providing motive power for liquid-propelled airplanes, rockets, boats, and cars as well as for stationary fuel cells and portable fuel cell applications capable of powering general motors (Hwang, 2013). Some of the challenges of using hydrogen as a fuel are related to it’s difficult to be stored in cryogenic or high-pressure tanks. Also, it is tough to extract it from the hydrogen bearing compounds (Hlina, 2014).
Hydrogen can be used as an alternative transportation fuel because of its potential to be produced domestically, its ability to be used to power fuel cells in electric cars with zero emissions as well as the high efficiency of the fuel cells (Ouda et al., 2015). Also, Hydrogen is used in the internal combustion engines, although it produces tailpipe emissions, reducing its effectiveness (Materazzi, 2014).
Aga, O., Ouda, O.K. and Raza, S.A., 2014, November. Investigating waste to energy potential in the Eastern Region, Saudi Arabia. In Renewable Energies for Developing Countries (REDEC), 2014 International Conference on (pp. 7-11). IEEE.
Agboola, P.O. and Saleh, J., 2016. Feasibility of municipal solid waste (MSW) as energy sources for Saudi Arabia’s future Reverse osmosis (RO) desalination plants. Polish Journal of Chemical Technology, 18(4), pp.82-89.
Andreadou, C. and Martinopoulos, G., 2016. CAPE-OPEN simulation of waste-to-energy technologies for urban cities. International Journal of Sustainable Energy, pp.1-9.
Anjum, M., Miandad, R., Waqas, M., Ahmad, I., Alafif, Z.O.A., Aburiazaiza, A.S., Barakat, M.A. and Akhtar, T., 2016. Solid waste management in Saudi Arabia: a review. J. Appl. Agric. Biotechnol, 1(1), pp.13-26.
Arena, U., Ardolino, F. and Di Gregorio, F., 2015. A life cycle assessment of environmental performances of two combustion-and gasification-based waste-to-energy technologies. Waste Management, 41, pp.60-74.
Astrup, T.F., Tonini, D., Turconi, R. and Boldrin, A., 2015. Life cycle assessment of thermal waste-to-energy technologies: review and recommendations. Waste management, 37, pp.104-115.
Bosmans, A., Vanderreydt, I., Geysen, D. and Helsen, L., 2013. The crucial role of Waste-to-Energy technologies in enhanced landfill mining: a technology review. Journal of Cleaner Production, 55, pp.10-23.
Cammack, R., Frey, M. and Robson, R. eds., 2015. Hydrogen as a fuel: learning from nature. CRC Press.
Demirbas, A., Alamoudı, R.H., Ahmad, W. and Sheıkh, M.H., 2016. Optimization of municipal solid waste (MSW) disposal in Saudi Arabia. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 38(13), pp.1929-1937.
Dodds, P.E., Staffell, I., Hawkes, A.D., Li, F., Grünewald, P., McDowall, W. and Ekins, P., 2015. Hydrogen and fuel cell technologies for heating: a review. International journal of hydrogen energy, 40(5), pp.2065-2083.
Hlina, M., Hrabovsky, M., Kavka, T. and Konrad, M., 2014. Production of high quality syngas from argon/water plasma gasification of biomass and waste. Waste management, 34(1), pp.63-66.
Hwang, J.J., 2013. Sustainability study of hydrogen pathways for fuel cell vehicle applications. Renewable and Sustainable Energy Reviews, 19, pp.220-229.
Ismail, I.M. and Nizami, A.S., 2016. ENV-617: WASTE-BASED BIOREFINERIES IN DEVELOPING COUNTRIES: AN IMPERATIVE NEED OF TIME.
Jannelli, E., Minutillo, M. and Perna, A., 2014. Hydrogen from intermittent renewable energy sources as plasma gas in integrated plasma gasification systems for waste treatment and electric energy production. Proceedings of SEEP2014, 23, p.25.
Khan, M.S.M. and Kaneesamkandi, Z., 2013. Biodegradable waste to biogas: renewable energy energy option for the Kingdom of Saudi Arabia. Int J Innov Appl Stud, 4(1), pp.101-113.
Lee, S., Speight, J.G. and Loyalka, S.K. eds., 2014. Handbook of alternative fuel technologies. crc Press.
Lucia, U., 2014. Overview on fuel cells. Renewable and Sustainable Energy Reviews, 30, pp.164-169.
Materazzi, M., Lettieri, P., Mazzei, L., Taylor, R. and Chapman, C., 2014. Tar evolution in a two in a two stage fluid bed–plasma gasification process for waste valorization. Fuel Processing Technology, 128, pp.146-157.
Miandad, R., Rehan, M., Ouda, O.K.M., Khan, M.Z., Shahzad, K., Ismail, I.M.I. and Nizami, A.S., 2017. Waste-to-hydrogen energy in Saudi Arabia: challenges and perspectives. In Biohydrogen Production: Sustainability of Current Technology and Future Perspective (pp. 237-252). Springer India.
Nizami, A.S., Ouda, O.K.M., Rehan, M., El-Maghraby, A.M.O., Gardy, J., Hassanpour, A., Kumar, S. and Ismail, I.M.I., 2016. The potential of Saudi Arabian natural zeolites in energy recovery technologies. Energy, 108, pp.162-171.
Nizami, A.S., Rehan, M., Ouda, O.K., Shahzad, K., Sadef, Y., Iqbal, T. and Ismail, I.M., 2015. An argument for developing waste-to-energy technologies in Saudi Arabia. Chem. Eng, 45, pp.337-342.
Nizami, A.S., Shahzad, K., Rehan, M., Ouda, O.K.M., Khan, M.Z., Ismail, I.M.I., Almeelbi, T., Basahi, J.M. and Demirbas, A., 2017. Developing waste biorefinery in Makkah: a way forward to convert urban waste into renewable energy. Applied Energy, 186, pp.189-196.
O’hayre, R., Cha, S.W., Prinz, F.B. and Colella, W., 2016. Fuel cell fundamentals. John Wiley & Sons.]
Ouda, O.K. and Cekirge, H.M., 2013. Roadmap for development of waste-to energy facility in Saudi Arabia. American Journal of Environmental Engineering, 3(6), pp.267-272.
Ouda, O.K., Raza, S.A., Al-Waked, R., Al-Asad, J.F. and Nizami, A.S., 2015. Waste-to-energy potential in the Western Province of Saudi Arabia. Journal of King Saud University-Engineering Sciences.
Ouda, O.K.M., Raza, S.A., Nizami, A.S., Rehan, M., Al-Waked, R. and Korres, N.E., 2016. Waste to energy potential: a case study of Saudi Arabia. Renewable and Sustainable Energy Reviews, 61, pp.328-340.
Pan, S.Y., Du, M.A., Huang, I.T., Liu, I.H., Chang, E.E. and Chiang, P.C., 2015. Strategies on implementation of waste-to-energy (WTE) supply chain for circular economy system: a review. Journal of Cleaner Production, 108, pp.409-421.
Panicker, Philip K., and Amani Magid. “Microwave Plasma Gasification for Enhanced Oil Recovery and Sustainable Waste Management.” In ASME 2016 10th International Conference on Energy Sustainability collocated with the ASME 2016 Power Conference and the ASME 2016 14th International Conference on Fuel Cell Science, Engineering and Technology, pp. V001T02A010-V001T02A010. American Society of Mechanical Engineers, 2016.
Perna, A., Minutillo, M. and Jannelli, E., 2016. Hydrogen from intermittent renewable energy sources as gasification medium in integrated waste gasification combined cycle power plants: A performance comparison. Energy, 94, pp.457-465.
Portugal-Pereira, J. and Lee, L., 2016. Economic and environmental benefits of waste-to-energy technologies for debris recovery in disaster-hit Northeast Japan. Journal of Cleaner Production, 112, pp.4419-4429.
Sharma, A.P., Gupta, S.K. and Mehta, S.B., 2016. RENEWABLE ENERGY SOURCES. Indian Journal of Applied Research, 6(1).
Sharma, S. and Ghoshal, S.K., 2015. Hydrogen the future transportation fuel: from production to applications. Renewable and sustainable energy reviews, 43, pp.1151-1158.
Tozlu, A., Özahi, E. and Abuşoğlu, A., 2016. Waste to energy technologies for municipal solid waste management in Gaziantep. Renewable and Sustainable Energy Reviews, 54, pp.809-815.
Verhelst, S., 2014. Recent progress in the use of hydrogen as a fuel for internal combustion engines. international journal of hydrogen energy, 39(2), pp.1071-1085.
Watkins, P. and McKendry, P., 2015. Assessment of waste derived gases as a renewable energy source–Part 1. Sustainable Energy Technologies and Assessments, 10, pp.102-113.
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