Enhancing power, water and biofuel multigeneration system through developed biomass-driven hybrid process with energy, exergy, economic and environmental (4E) analysis
Seyed Taher Kermani Alghorayshi, Milad Imandoust, Ali Montazeri, Samaneh Ayoubi, Rahim Zahedi
Abstract
In recent years, the use of solar and biomass energy in tandem manufacturing has surged, driven by a growing awareness of environmental concerns and the potential for cost savings. These processes not only generate clean power and fresh water but also contribute to other essential needs, improving overall resource management. Previous articles highlighted the effective and suitable design of the power, water, and biogas triple production process, emphasizing its seamless integration. Systems using solar heat, however, incur additional costs from the need for heat storage and larger solar collector areas during periods of low or no sunlight. Solar collectors account for the greatest energy and exergy losses. This research seeks to develop a continuous, high-performance biomass-only process, eliminating the need for solar collectors. This design removes solar energy's nighttime limitations and eliminates costly heat storage, benefiting the environment and the economy. Therefore, four power generation processes were designed to convert the synthesis gas produced in the previous step, including syngas purification, methanol production, and dimethyl ether production (using ASPEN Plus & ASPEN Economic). Performance evaluations of all four processes included energy, exergy, economic, and life cycle analyses. The current power cycle process shows a marked improvement in both energy and exergy efficiency compared to previous iterations. Energy and exergy efficiencies in the initial process were 42.2 % and 35.5 %, respectively. In contrast, the current process, utilizing methanol (MEOH) and dimethyl ether (DME), shows improved energy efficiencies of 82.5 % and 74.1 %, and exergy efficiencies of 61.2 % and 58.6 %, respectively. In the Rectisol process, energy efficiency is high, showing energy and exergy drops of −5.8 and −2.08 units respectively. The Rectisol, MEOH, DME, and combined cycle processes generated 5.59, 0, 9.67, and 37.53 MW (MW), respectively. Freshwater production for these processes reached 1186.5, 933.5, 1295, and 1223 cubic meters per hour (m 3 /h). The Rectisol, MEOH, and DME processes also yielded 77,374 kg/h of sweet syngas, along with 42,603 kg/h of methanol and 30,539.5 kg/h of DME as a byproduct. The DME process is considerably more environmentally friendly. In the long run, DME implementation will create a cost-effective and efficient process benefiting the global community.